Quiet Gitea prebuilt fallback

Implicit sessions (dosh host with no --session) get a random
term-<millis>-<pid> name you can never reattach to, so persisting them just
left unreattachable holder processes lingering across restarts. The server
now only uses a persistent holder for prewarmed or explicitly-named
sessions; implicit ones use the in-process shell that dies on restart and
reaps on disconnect, as before. Adds a shared
protocol::{generate,is}_implicit_session_name as the single source of truth
for the name shape, used by both client (generate) and server (detect).

Server-only behavior change; wire VERSION unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -3,6 +3,9 @@ name: ci
 on:
   push:
   pull_request:
+  workflow_dispatch:
+  schedule:
+    - cron: "17 7 * * 1"
 
 jobs:
   test:
@@ -36,21 +39,42 @@ jobs:
         if: steps.nightly.outcome == 'success' && steps.install.outcome == 'success'
         run: |
           set -e
-          for target in \
+          if [ "${{ github.event_name }}" = "schedule" ] || [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
-            packet_decode \
+            DOSH_FUZZ_SECONDS="${DOSH_FUZZ_SECONDS:-300}" sh scripts/fuzz-run.sh
-            from_body \
+          else
-            authorized_keys \
+            sh scripts/fuzz-run.sh 20
-            known_hosts \
+          fi
-            handshake_structs \
-            attach_ticket; do
-            echo "== fuzzing $target =="
-            cargo +nightly fuzz run --fuzz-dir fuzz "$target" -- \
-              -max_total_time=20 -rss_limit_mb=4096
-          done
       - name: Note when fuzzing was skipped
         if: steps.nightly.outcome != 'success' || steps.install.outcome != 'success'
         run: echo "cargo-fuzz / nightly toolchain unavailable; skipped fuzz smoke run."
 
+  package-release:
+    if: github.event_name == 'workflow_dispatch' || startsWith(github.ref, 'refs/tags/')
+    strategy:
+      matrix:
+        include:
+          - os: ubuntu-latest
+            name: linux-x86_64
+          - os: macos-14
+            name: macos-aarch64
+          - os: macos-13
+            name: macos-x86_64
+          - os: windows-latest
+            name: windows-x86_64
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - name: Package release
+        shell: bash
+        run: sh scripts/package-release.sh
+      - uses: actions/upload-artifact@v4
+        with:
+          name: dosh-${{ matrix.name }}
+          path: |
+            target/dosh-release/dosh-*
+            !target/dosh-release/stage/**
+
   remote-bench:
     runs-on: ubuntu-latest
     env:

Cargo.lock

@@ -397,6 +397,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e7c1832837b905bbfb5101e07cc24c8deddf52f93225eee6ead5f4d63d53ddcb"
 dependencies = [
  "const-oid",
+ "pem-rfc7468",
  "zeroize",
 ]
 
@@ -448,11 +449,14 @@ dependencies = [
  "ed25519-dalek",
  "hkdf",
  "hmac",
+ "libc",
  "portable-pty",
  "rand",
  "rpassword",
+ "rsa",
  "serde",
  "sha2",
+ "signature",
  "ssh-key",
  "tempfile",
  "tokio",
@@ -1498,6 +1502,7 @@ checksum = "3b86f5297f0f04d08cabaa0f6bff7cb6aec4d9c3b49d87990d63da9d9156a8c3"
 dependencies = [
  "bcrypt-pbkdf",
  "ed25519-dalek",
+ "num-bigint-dig",
  "p256",
  "p384",
  "p521",

Cargo.toml

@@ -16,12 +16,15 @@ dirs = "5.0"
 ed25519-dalek = "2.1"
 hkdf = "0.12"
 hmac = "0.12"
+libc = "0.2"
 portable-pty = "0.8"
 rand = "0.8"
+rsa = { version = "0.9.10", features = ["sha2"] }
 rpassword = "7.5.4"
 serde = { version = "1.0", features = ["derive"] }
 sha2 = "0.10"
-ssh-key = { version = "0.6.7", features = ["ed25519", "encryption"] }
+signature = "2.2"
+ssh-key = { version = "0.6.7", features = ["ed25519", "encryption", "p256", "rsa"] }
 tokio = { version = "1.41", features = ["full"] }
 toml = "0.8"
 vt100 = "0.15"

Makefile

@@ -1,4 +1,4 @@
-.PHONY: build test fmt install bench-local bench-local-json bench-docker-ssh bench-docker-mosh
+.PHONY: build test fmt install package-release bench-report bench-local bench-local-json bench-docker-ssh bench-docker-mosh fuzz-smoke fuzz-deep soak-local
 
 build:
 	cargo build --release
@@ -12,6 +12,12 @@ fmt:
 install:
 	sh packaging/install.sh
 
+package-release:
+	sh scripts/package-release.sh
+
+bench-report:
+	sh scripts/bench-report.sh
+
 # Safe, self-contained local benchmark matrix (native cold auth, cached attach
 # ticket, local-auth) on a throwaway server bound to 127.0.0.1 on a free port in
 # a temp HOME. Never touches the production server or UDP port 50000.
@@ -28,3 +34,14 @@ bench-docker-ssh:
 
 bench-docker-mosh:
 	DOSH_BENCH_INCLUDE_MOSH=1 sh scripts/ci-docker-ssh-bench.sh
+
+fuzz-smoke:
+	sh scripts/fuzz-run.sh 20
+
+# Longer pre-launch fuzz pass. Override with DOSH_FUZZ_SECONDS=NN.
+fuzz-deep:
+	DOSH_FUZZ_SECONDS=$${DOSH_FUZZ_SECONDS:-300} sh scripts/fuzz-run.sh
+
+# 30-minute launch soak by default. Override with DOSH_SOAK_SECONDS=NN.
+soak-local:
+	DOSH_SOAK_SECONDS=$${DOSH_SOAK_SECONDS:-1800} cargo test --test integration_smoke sleep_roaming_soak_30m -- --ignored --nocapture

README.md

@@ -81,6 +81,9 @@ dosh-server
   client table per session
   encrypted UDP protocol
   tiny SSH-invoked dosh-auth helper mode
+  persistent sessions (persist_sessions, currently opt-in): each shell runs in a
+    detached per-session holder process; the server adopts its PTY master fd via
+    SCM_RIGHTS and re-adopts it after a restart, so sessions survive crash/upgrade
 
 dosh-client
   terminal raw mode
@@ -107,33 +110,42 @@ Install the client on macOS:
 
 ```bash
 curl -fsSL https://git.palav.dev/Palav/dosh/raw/branch/main/install.sh \
-  | DOSH_REPO=https://git.palav.dev/Palav/dosh.git DOSH_SERVER=palav DOSH_HOST=git.palav.dev DOSH_PORT=50000 sh -s -- client
+  | DOSH_REPO=https://git.palav.dev/Palav/dosh.git DOSH_PORT=50000 sh -s -- client
 ```
 
 Update an installed client later:
 
 ```bash
 dosh update
+dosh update --check
+dosh --version
 ```
 
+`dosh update` first tries a release tarball named for the platform
+(`dosh-macos-aarch64.tar.gz`, `dosh-linux-x86_64.tar.gz`, etc.) from the latest
+Gitea/GitHub release. If that asset is not published yet, it falls back to the
+source build path. If the release also publishes `<artifact>.sha256`, the installer
+verifies the archive before installing it.
+
 Install the client on Windows PowerShell:
 
 ```powershell
-$env:DOSH_REPO="https://git.palav.dev/Palav/dosh.git"; $env:DOSH_SERVER="palav"; $env:DOSH_HOST="git.palav.dev"; $env:DOSH_PORT="50000"; irm https://git.palav.dev/Palav/dosh/raw/branch/main/install.ps1 | iex
+$env:DOSH_REPO="https://git.palav.dev/Palav/dosh.git"; $env:DOSH_PORT="50000"; irm https://git.palav.dev/Palav/dosh/raw/branch/main/install.ps1 | iex
 ```
 
 Attach:
 
 ```bash
-dosh palav
+dosh user@server.example.com
 ```
 
-Plain `dosh palav` opens a fresh terminal session. Use named sessions when you want
+Plain `dosh user@server.example.com` opens a fresh terminal session. Use named
-to reattach to the same persistent terminal from multiple clients:
+sessions when you want to reattach to the same persistent terminal from multiple
+clients:
 
 ```bash
-dosh --session work palav
+dosh --session work user@server.example.com
-dosh --session logs palav
+dosh --session logs user@server.example.com
 ```
 
 Press `Ctrl-]` to detach the current client while leaving the server session alive.
@@ -159,7 +171,31 @@ UDP host from an SSH alias when `dosh_host` is not configured. To make that expl
 in Dosh's host config:
 
 ```bash
-dosh import-ssh palav homelab
+dosh import-ssh homelab
+dosh homelab
+```
+
+Optional command extensions are just config-side startup shortcuts; Dosh has no
+compile-time dependency on the tools they run. For example, to make a separately
+installed server-side `tm` dashboard easy to open:
+
+```toml
+# ~/.config/dosh/client.toml
+[extensions.tm]
+command = "tm {args}"
+description = "Open the server-side tmux dashboard"
+```
+
+Then `dosh homelab tm` sends `tm`, and `dosh homelab tm dosh` sends `tm 'dosh'`.
+Remove that table to remove the integration. Hosts can override or opt out:
+
+```toml
+# ~/.config/dosh/hosts.toml
+[homelab.extensions.tm]
+command = "/opt/tm/bin/tm {args}"
+
+[other-host.extensions.tm]
+disabled = true
 ```
 
 ## Develop
@@ -194,9 +230,9 @@ Benchmark the ControlMaster-backed SSH bootstrap path:
 target/release/dosh-bench --server user@host --controlmaster --iterations 3
 ```
 
-Run the Docker OpenSSH benchmark gate used by CI. It checks both cold SSH bootstrap
+Run the Docker OpenSSH benchmark gate used by CI. It checks cold SSH bootstrap,
-and ControlMaster-backed SSH bootstrap against a containerized `sshd` plus resident
+ControlMaster-backed SSH bootstrap, native cold auth after one-time `dosh trust`,
-`dosh-server`:
+and cached attach against a containerized `sshd` plus resident `dosh-server`:
 
 ```bash
 make bench-docker-ssh
@@ -208,12 +244,39 @@ Run the same Docker comparison with Mosh installed in the benchmark container:
 make bench-docker-mosh
 ```
 
-That prints `ssh_true_ms`, `dosh_attach_ms`, and `mosh_start_true_ms` under the same
+That prints `ssh_true_ms`, `dosh_attach_ms`, `dosh_cold_native_ms`,
-container, key, DNS, and network path. It also prints `dosh_cached_attach_ms`, which
+`dosh_cached_attach_ms`, and, for the Mosh target, `mosh_start_true_ms` under the
-is the real Dosh fast path after the first SSH-authenticated bootstrap has issued an
+same container, key, DNS, and network path. `dosh_cached_attach_ms` is the real Dosh
-attach ticket. See `docs/PUBLIC_READINESS.md` before using the numbers publicly;
+fast path after the first authentication has issued an attach ticket. See
-Dosh's current strongest claim is fast attach/reconnect, not full Mosh feature
+`docs/PUBLIC_READINESS.md` before using the numbers publicly; Dosh's current
-parity yet.
+strongest claim is fast attach/reconnect plus native encrypted forwarding on
+Dosh-installed servers, not generic SSH compatibility.
+
+The latest local release evidence is in
+`docs/RELEASE_EVIDENCE_2026-06-20.md`.
+
+Generate a publishable Markdown benchmark report:
+
+```bash
+make bench-report
+```
+
+Set `DOSH_BENCH_SERVER`, `DOSH_BENCH_ITERS`, `DOSH_BENCH_ARGS`, and
+`DOSH_BENCH_REPORT` to target a real host and choose the output path.
+
+Run the explicit pre-launch soak and fuzz gates:
+
+```bash
+make soak-local                 # 30-minute sleep/roaming gate by default
+make fuzz-deep                  # 5 minutes per fuzz target by default
+```
+
+Both are configurable for shorter local shakedowns:
+
+```bash
+DOSH_SOAK_SECONDS=30 make soak-local
+DOSH_FUZZ_SECONDS=60 make fuzz-deep
+```
 
 The CI workflow includes an optional remote benchmark job. It runs when
 `DOSH_BENCH_HOST`, `DOSH_BENCH_USER`, and `DOSH_BENCH_SSH_KEY` repository secrets are
@@ -225,6 +288,13 @@ Install release binaries and the user systemd service:
 make install
 ```
 
+Build release tarballs for upload to Gitea/GitHub releases:
+
+```bash
+make package-release
+GITEA_TOKEN=... scripts/upload-gitea-release.sh v0.1.0 target/dosh-release/dosh-*
+```
+
 ## Performance Rules
 
 The stack is performance-driven, not fixed by taste. Rust is the default because the
@@ -259,7 +329,8 @@ Hot-path rules:
 
 - Replacing SSH as the first public-key trust mechanism.
 - Multi-user access control.
-- Windows support in v0.
+- Windows server/full parity in v0; the client installer supports prebuilt Windows
+  client artifacts when published.
 - Full mosh compatibility.
 - Perfect predictive local echo in the first MVP.
 
@@ -278,10 +349,10 @@ Beyond the SSH-bootstrap core, native v1 (`docs/NATIVE_V1_SPEC.md`) is substanti
 implemented and aims to replace the day-to-day `ssh host` workflow on Dosh-installed
 servers:
 
-- **Native UDP auth** with X25519 key exchange, transcript-bound Ed25519 user auth
+- **Native UDP auth** with X25519 key exchange; transcript-bound Ed25519, ECDSA
-  via ssh-agent or an encrypted OpenSSH key, ChaCha20-Poly1305 transport, and
+  P-256, and RSA-SHA2 user auth via ssh-agent or OpenSSH identity files;
-  `authorized_keys` policy enforcement (`from=`, `no-port-forwarding`, `permitopen=`;
+  ChaCha20-Poly1305 transport; and `authorized_keys` policy enforcement (`from=`,
-  unsupported options fail closed).
+  `no-port-forwarding`, `permitopen=`; unsupported options fail closed).
 - **Dosh host-key trust**: pinned `known_hosts`, `dosh trust [--remove|--replace]`,
   TOFU only when explicitly enabled, and hard-fail on host-key mismatch.
 - **TCP forwarding**: local `-L`, remote `-R` (loopback bind by default), dynamic
@@ -300,10 +371,12 @@ the native authenticated path is tried first and falls back to SSH bootstrap
 explicitly when native auth is disabled, unavailable, or rejected. It never silently
 degrades to an unauthenticated mode.
 
-Native v1 is **not yet fully verified**. Per-IP token-bucket rate limiting, protocol
+Native v1 is **not externally audited yet**. Local 30-minute sleep/roaming soak,
-VERSION negotiation hardening, fuzzing in CI, ECDSA/RSA user keys, and an external
+fuzz-smoke, and Docker SSH/Mosh benchmark evidence is captured in
-security review are still open. See `docs/THREAT_MODEL.md` for the published threat
+`docs/RELEASE_EVIDENCE_2026-06-20.md`. See `docs/THREAT_MODEL.md` for the
-model and accepted residual risks, and the "Native v1 verification checklist status"
+published threat model and accepted residual risks, `docs/PROTOCOL_VERSIONING.md`
-table in `docs/PUBLIC_READINESS.md` for the item-by-item state. Dosh does not yet
+for the v1 versioning policy, `docs/AUDIT_PACKET.md` for the external security
-claim a fully verified SSH replacement; its defensible claim remains fast encrypted
+review handoff, and the "Native v1 verification checklist status" table in
-native attach/reconnect with SSH-equivalent transport security and SSH fallback.
+`docs/PUBLIC_READINESS.md` for the item-by-item state. Dosh does not claim generic
+SSH compatibility; its defensible claim is fast encrypted native attach/reconnect
+and forwarding on Dosh-installed servers with SSH bootstrap fallback.

SPEC.md

@@ -468,6 +468,8 @@ dosh_port = 50000
 default_session = "new"
 reconnect_timeout_secs = 5
 view_only = false
+predict = true
+predict_mode = "experimental"
 cache_attach_tickets = true
 credential_cache = "~/.local/share/dosh/credentials"
 ```

docs/AUDIT_PACKET.md

@@ -0,0 +1,75 @@
+# Dosh Native v1 Audit Packet
+
+This is the handoff checklist for an external security review.
+
+## Scope
+
+Review the security properties of Dosh native v1:
+
+- Native UDP authentication and key exchange
+- Host key trust and known-host mismatch behavior
+- Authorized key parsing and policy enforcement
+- Transport encryption, replay protection, rekeying, resume, and stale packet handling
+- Attach ticket sealing/opening
+- TCP forwarding and agent forwarding authorization boundaries
+- Parser robustness for untrusted wire/config data
+
+Primary files:
+
+- `src/native.rs`
+- `src/protocol.rs`
+- `src/auth.rs`
+- `src/ssh_agent.rs`
+- `src/bin/dosh-client.rs`
+- `src/bin/dosh-server.rs`
+- `src/config.rs`
+- `tests/parser_robustness.rs`
+- `tests/protocol_auth.rs`
+- `tests/hostile_network.rs`
+- `tests/integration_smoke.rs`
+- `fuzz/fuzz_targets/*`
+
+Primary docs:
+
+- `docs/NATIVE_V1_SPEC.md`
+- `docs/THREAT_MODEL.md`
+- `docs/PROTOCOL_VERSIONING.md`
+- `docs/PUBLIC_READINESS.md`
+- `docs/RELEASE_EVIDENCE_2026-06-20.md`
+
+## Required Reviewer Questions
+
+1. Is the native handshake transcript complete enough to bind client/server keys,
+   requested session, mode, env, and forwarding permissions?
+2. Are host-key trust transitions fail-closed, especially unknown vs mismatch vs
+   explicit TOFU?
+3. Are authorized-key options parsed conservatively enough, and are unsupported
+   options rejected safely?
+4. Can replayed, reordered, delayed, stale, or cross-epoch packets affect terminal
+   input or forwarded streams more than once?
+5. Does key rotation preserve confidentiality without creating split-brain epoch
+   states?
+6. Do attach tickets create any bearer-token replay or privilege-extension issue?
+7. Can UDP endpoint migration be abused for hijack or reflection?
+8. Are local/remote/dynamic TCP forwarding and agent forwarding gated correctly by
+   client opt-in, server config, and authorized-key options?
+9. Are parser and packet-size limits sufficient against malicious inputs?
+10. Are there any unsafe assumptions in process/session persistence or holder
+    adoption?
+
+## Current Local Evidence
+
+As of 2026-06-20:
+
+- `cargo test`: `153 passed, 1 ignored`
+- `make soak-local`: passed 30-minute sleep/roaming soak
+- `make fuzz-smoke`: passed all configured fuzz targets for 20s each
+- `make bench-docker-mosh`: passed SSH, ControlMaster, native, cached, and Mosh
+  comparison gates
+
+## Explicit Non-Claims Before Audit
+
+- No claim of generic SSH protocol replacement.
+- No claim of full Mosh compatibility.
+- No claim that native v1 is externally audited.
+- No claim that Windows server support is production-ready.

docs/BENCHMARKS.md

@@ -17,6 +17,7 @@ make bench-local          # safe, self-contained matrix on a throwaway server
 make bench-local-json     # same, machine-readable JSON with raw samples
 make bench-docker-ssh     # containerized SSH-vs-Dosh gate used by CI
 make bench-docker-mosh    # same, with Mosh installed for a three-way comparison
+make bench-report         # Markdown report wrapper around dosh-bench
 ```
 
 `make bench-local` never touches a running production server: it builds release
@@ -35,7 +36,8 @@ tool pays before any useful remote work begins.
 Every run prints, per metric, a summary line (count, min, median, p95, mean, max
 in milliseconds) **and** a raw-samples line. Pass `--json` for one machine-readable
 object per run (with the full `samples_ms` array) so published numbers can always
-include raw data, as required by `docs/PUBLIC_READINESS.md`.
+include raw data, as required by `docs/PUBLIC_READINESS.md`. Pass `--markdown` for a
+publishable Markdown table, and `--output path/to/report.md` to write it to disk.
 
 ### Path matrix
 
@@ -93,11 +95,13 @@ Tunables: `scripts/bench-local.sh [ITERATIONS]` (default 20), `DOSH_BENCH_JSON=1
 ### `make bench-docker-ssh` / `make bench-docker-mosh` (`scripts/ci-docker-ssh-bench.sh`)
 
 Builds one Ubuntu image with OpenSSH, `dosh-server`, `dosh-auth` (and Mosh for the
-`-mosh` target), then runs `ssh_true_ms`, cold + ControlMaster `dosh_attach_ms`,
+`-mosh` target), then runs `ssh_true_ms`, cold + ControlMaster SSH-bootstrap
-`dosh_cached_attach_ms`, and optionally `mosh_start_true_ms` against the same
+`dosh_attach_ms`, one-time `dosh trust` followed by native-cold
-container, key, and loopback network path. This is the gate CI enforces; it asserts
+`dosh_cold_native_ms`, `dosh_cached_attach_ms`, and optionally
-cold Dosh stays within 500 ms of SSH and that cached attach stays under a small
+`mosh_start_true_ms` against the same container, key, and loopback network path.
-budget. See `README.md` "Develop" for the exact invocations.
+This is the gate CI enforces; it asserts cold SSH-bootstrap Dosh stays within
+500 ms of SSH, native-cold Dosh beats SSH mean by default, and cached attach stays
+under a small budget. See `README.md` "Develop" for the exact invocations.
 
 ## Methodology and caveats
 
@@ -130,8 +134,8 @@ budget. See `README.md` "Develop" for the exact invocations.
 
 ## Sample results (loopback, self-contained)
 
-Captured with `make bench-local` (`scripts/bench-local.sh 30`), all times in
+Captured with `make bench-local` (`scripts/bench-local.sh 20`), all times in
-milliseconds, 30 samples per metric.
+milliseconds, 20 samples per metric.
 
 - Machine: Intel Core i5-9500 @ 3.00 GHz, 6 cores
 - OS: Ubuntu 24.04.4 LTS, Linux 6.8.0-124-generic, x86_64
@@ -141,27 +145,24 @@ milliseconds, 30 samples per metric.
 
 | Metric | n | min | median | p95 | mean | max |
 | --- | --- | --- | --- | --- | --- | --- |
-| `dosh_cold_native_ms` | 30 | 8.10 | 9.01 | 10.40 | 9.18 | 10.82 |
+| `dosh_cold_native_ms` | 20 | 8.32 | 8.77 | 9.34 | 8.82 | 9.52 |
-| `dosh_cached_attach_ms` | 30 | 2.73 | 2.96 | 3.25 | 2.96 | 3.30 |
+| `dosh_cached_attach_ms` | 20 | 2.83 | 3.23 | 3.75 | 3.24 | 3.77 |
-| `dosh_local_attach_ms` | 30 | 2.66 | 2.78 | 3.24 | 2.87 | 3.33 |
+| `dosh_local_attach_ms` | 20 | 2.84 | 3.21 | 3.96 | 3.28 | 3.98 |
 
 Raw samples (ms):
 
 ```
 dosh_cold_native_ms:
-8.32, 8.23, 10.31, 10.37, 8.83, 8.81, 9.20, 9.04, 10.14, 8.98, 10.82, 9.87,
+8.82, 8.60, 8.69, 8.71, 9.33, 8.82, 8.90, 8.64, 8.39, 8.75, 8.79, 8.70, 8.64,
-10.22, 10.42, 9.76, 9.09, 9.19, 8.94, 8.69, 8.67, 8.74, 9.33, 9.25, 8.92, 8.39,
+9.52, 8.72, 8.32, 9.06, 8.93, 8.96, 9.04
-8.55, 8.38, 9.81, 8.17, 8.10
 
 dosh_cached_attach_ms:
-2.99, 2.99, 2.93, 2.87, 2.95, 2.80, 2.80, 2.90, 3.10, 2.73, 3.19, 2.80, 2.87,
+3.04, 3.06, 2.98, 2.91, 2.96, 2.95, 3.05, 3.66, 3.37, 2.88, 2.83, 3.16, 3.49,
-2.82, 2.89, 3.03, 3.06, 3.21, 2.97, 2.83, 3.00, 2.82, 3.04, 2.97, 3.03, 3.24,
+3.30, 3.77, 3.32, 3.49, 3.75, 3.56, 3.33
-3.30, 2.73, 2.79, 3.25
 
 dosh_local_attach_ms:
-3.05, 3.00, 2.84, 3.04, 3.33, 2.89, 2.76, 2.74, 2.73, 3.32, 3.14, 2.75, 2.83,
+3.08, 3.96, 3.36, 3.30, 2.88, 2.99, 3.96, 3.98, 3.25, 2.84, 3.29, 3.59, 3.65,
-2.88, 2.99, 2.77, 2.75, 2.79, 2.69, 2.78, 2.75, 2.77, 2.75, 2.77, 3.03, 2.75,
+3.47, 3.13, 2.92, 2.87, 2.91, 2.98, 3.18
-2.94, 2.74, 2.82, 2.66
 ```
 
 Reading these numbers: cold native auth is ~9 ms because it pays the native
@@ -171,3 +172,32 @@ overhead floor. Over a real link, expect cached attach ≈ this floor + one netw
 round trip — which is exactly the "near network RTT" target in the spec. There is
 no SSH/Mosh baseline in this loopback table because those paths need an SSH server;
 use `make bench-docker-ssh` / `make bench-docker-mosh` for the head-to-head.
+
+## Sample results (Docker SSH/Mosh comparison)
+
+Captured with `make bench-docker-mosh`, all times in milliseconds. This is the
+same-container comparison gate: one generated key, one OpenSSH server, one
+`dosh-server`, loopback-published TCP/UDP ports.
+
+| Metric | n | min | median | p95 | mean | max |
+| --- | --- | --- | --- | --- | --- | --- |
+| `ssh_true_ms` (cold SSH baseline for native-cold gate) | 5 | 214.53 | 216.84 | 220.55 | 217.60 | 220.91 |
+| `dosh_cold_native_ms` | 5 | 8.62 | 8.96 | 9.78 | 9.15 | 9.88 |
+| `dosh_cached_attach_ms` | 10 | 8.41 | 8.83 | 9.52 | 8.90 | 9.53 |
+| `mosh_start_true_ms` | 3 | 528.03 | 530.87 | 539.23 | 533.02 | 540.16 |
+
+Raw samples (ms):
+
+```
+ssh_true_ms (native-cold gate):
+216.84, 216.61, 214.53, 220.91, 219.09
+
+dosh_cold_native_ms:
+9.39, 8.88, 8.96, 8.62, 9.88
+
+dosh_cached_attach_ms:
+8.44, 8.41, 8.80, 8.48, 9.53, 9.51, 8.85, 8.69, 9.33, 8.96
+
+mosh_start_true_ms:
+540.16, 528.03, 530.87
+```

docs/NATIVE_V1_SPEC.md

@@ -7,16 +7,22 @@
 > - Milestone 1 — host identity and trust: **done.** Host key generation, `dosh trust`,
 >   `known_hosts`, and mismatch hard-fail are implemented.
 > - Milestone 2 — native user auth: **done.** `ClientHello`/`ServerHello`/`UserAuth`/
->   `AuthOk`, ssh-agent and encrypted-key Ed25519, and `authorized_keys` verification
+>   `AuthOk`, ssh-agent and OpenSSH identity-file auth for Ed25519, ECDSA P-256,
->   exist. ECDSA/RSA user keys are still pending (Ed25519 only today).
+>   and RSA-SHA2, plus `authorized_keys` verification, exist.
 > - Milestone 3 — default native auth: **done.** `auth_preference = "native,ssh"` is
->   the default with explicit, visible SSH fallback. Cold-auth benchmark gates are
+>   the default with explicit, visible SSH fallback. Local and Docker benchmark gates
->   pending (Track C / `BENCHMARKS.md`).
+>   cover cached attach, SSH fallback, and native cold auth (Track C /
-> - Milestone 4 — forwarding: **done.** Stream mux, `-L`, `-R`, `-D`, `-N`, `-f`, and
+>   `BENCHMARKS.md`).
->   per-stream flow control are implemented; hostile-network and load tests pending.
+> - Milestone 4 — forwarding: **implemented.** Stream mux, `-L`, `-R`, `-D`, `-N`,
-> - Milestone 5 — hardening: **in progress.** Full per-IP token-bucket rate limiting,
+>   `-f`, per-stream flow control, ordered stream offsets/ACKs, and stream-data
->   protocol VERSION negotiation hardening, fuzzing in CI, and external review are not
+>   retransmission exist. Terminal-priority/load, replay/reorder, and dropped
->   yet complete. The threat model is published (`docs/THREAT_MODEL.md`).
+>   server-to-client `StreamData` recovery regressions are covered.
+> - Milestone 5 — hardening: **partly done.** Per-IP token-bucket rate limiting,
+>   fail-closed protocol-version checks with a documented v1 policy, parser fuzz
+>   targets, fuzz-smoke/deep CI entry points, scripted TUI transport tests,
+>   forwarding load/priority/replay/loss tests, and independent persistent session
+>   restart tests exist. Published long-soak evidence is not yet complete. The threat
+>   model is published (`docs/THREAT_MODEL.md`).
 > - Milestone 6 — workflow parity: **mostly done.** `dosh doctor`, host-trust
 >   management, and the encrypted-key prompt flow exist; cross-OS daily-driver soak is
 >   ongoing.
@@ -45,6 +51,7 @@ dosh -L 8080:127.0.0.1:80 host
 dosh -R 9000:127.0.0.1:9000 host
 dosh --session work host
 dosh --view-only --session work host
+dosh host tm
 ```
 
 Compatibility expectations:
@@ -101,6 +108,8 @@ Must work in v1:
 - `dosh update`.
 - `dosh doctor host` for config/auth/UDP reachability diagnostics.
 - `dosh sessions host` for session visibility.
+- Optional command extensions such as `dosh host tm` for companion tools that are
+  installed separately from Dosh.
 
 Should work in v1 if it does not compromise the transport schedule:
 
@@ -123,8 +132,14 @@ Native v1 must be boring under real use:
 
 - A closed laptop must not kill the remote session.
 - A client crash must not kill the remote session.
-- Server restart may drop live PTYs in v1 unless session persistence is implemented,
+- A server restart must not kill the remote session when `persist_sessions` is on
-  but the client must fail clearly and reconnect cleanly afterward.
+  (currently opt-in until stress-tested): each session's shell runs in a detached
+  per-session *holder*
+  process whose PTY master fd the server passes back to itself via SCM_RIGHTS, so
+  the shell + scrollback survive a server crash/upgrade/`systemctl restart` and a
+  reattaching client lands on the same shell with its screen restored. With
+  `persist_sessions = false` the old behavior applies: live PTYs drop on restart,
+  but the client must still fail clearly and reconnect cleanly afterward.
 - Decrypt failures from stale packets must be ignored or trigger reconnect, never
   terminate the terminal by themselves.
 - Terminal cleanup must restore cursor, mouse mode, bracketed paste, alternate
@@ -461,6 +476,12 @@ Forwarding rules:
 
 - Terminal traffic has priority over stream bulk data.
 - Each stream has independent flow control.
+- `StreamData` carries a per-stream byte offset and is delivered to TCP in order.
+- `StreamWindowAdjust` carries a cumulative received byte offset; peers free
+  retransmit buffers and replenish send credit only for acknowledged contiguous
+  bytes.
+- Unacknowledged stream bytes are retransmitted as newly encrypted transport packets
+  with fresh packet sequence numbers/nonces.
 - Backpressure must not block PTY input or output.
 - Server enforces `no-port-forwarding` and `permitopen=`.
 - Remote listeners bind to loopback by default.
@@ -538,6 +559,10 @@ forward_agent = false
 send_env = ["LANG", "LC_*", "TERM", "COLORTERM"]
 set_env = {}
 forwardings = []
+
+[extensions.tm]
+command = "tm {args}"
+description = "Open an optional server-side tmux dashboard"
 ```
 
 Server:
@@ -588,7 +613,7 @@ Milestone 5: hardening
 
 - Fuzz packet parsing, authorized-key parsing, known-host parsing, and handshake state.
 - Add hostile-network integration tests.
-- Add external review checklist before public security claims.
+- Keep a public hardening checklist and threat model before public security claims.
 
 Milestone 6: workflow parity
 

docs/PROTOCOL_VERSIONING.md

@@ -0,0 +1,40 @@
+# Dosh Protocol Versioning
+
+Dosh v1 uses a deliberately simple compatibility policy: **single-version,
+fail-closed, explicit error**.
+
+The wire header carries `protocol::VERSION`. The native handshake carries
+`native::NATIVE_PROTOCOL_VERSION`. A peer that speaks any other version is rejected
+before application data is accepted:
+
+- foreign wire `VERSION` packets get an `AttachReject` with
+  `protocol version mismatch - upgrade dosh`;
+- foreign native handshake `protocol_version` values get the same named upgrade
+  error with local/remote versions;
+- there is no silent downgrade, compatibility fallback, or best-effort decoding.
+
+## When To Bump
+
+Bump `protocol::VERSION` when a change affects packet framing, packet kind meaning,
+serialized protocol structs carried outside native handshake negotiation, or anything
+an older peer could misparse.
+
+Bump `native::NATIVE_PROTOCOL_VERSION` when a change affects native handshake
+transcripts, native auth semantics, algorithm negotiation, attach tickets, or any
+field that is signed or key-derived by native auth.
+
+If both layers are affected, bump both.
+
+## Compatibility Window
+
+Native v1 supports exactly the current version. That keeps the implementation small
+and makes security review tractable. Multi-version negotiation can be added later
+only with an explicit downgrade-resistance design:
+
+- negotiated version must be transcript-bound;
+- the selected version must be visible in diagnostics;
+- tests must prove an active attacker cannot force an older mutually supported
+  version;
+- unsupported peers must still get the same named upgrade error.
+
+Until that exists, the public policy is: upgrade both sides together.

docs/PUBLIC_READINESS.md

@@ -1,21 +1,21 @@
 # Dosh Public Readiness
 
-Dosh's defensible public claim is fast terminal attach and reconnect. It should not
+Dosh's defensible public claim is fast terminal attach/reconnect plus native
-claim full Mosh replacement status until the feature matrix below is green and the
+encrypted forwarding on Dosh-installed servers. It should not claim generic SSH
-comparison benchmark is reproducible outside the author's homelab.
+compatibility unless it implements the SSH protocol, and public benchmark claims
+must be reproducible outside the author's homelab.
 
 The plan for replacing the day-to-day SSH workflow with native Dosh authentication
 and forwarding is specified in `docs/NATIVE_V1_SPEC.md`, and the published threat
 model is in `docs/THREAT_MODEL.md`. Native v1 is now substantially implemented:
 native key-exchange + user auth, host-key pinning/trust, `-L`/`-R`/`-D` forwarding,
-and `dosh doctor` all exist (see the feature matrix and the verification-checklist
+`dosh doctor`, token-bucket auth rate limiting, and fuzz-smoke CI all exist (see the
-status table below). It is **not yet fully verified**: per-IP token-bucket rate
+feature matrix and the verification-checklist status table below). It is **not yet
-limiting, protocol-version negotiation hardening, fuzzing in CI, and external review
+fully verified**: long sleep/roaming soak and deeper fuzzing results are still open
-are still open. Until the verification checklist (`NATIVE_V1_SPEC.md` section 16) is
+launch evidence. Until the verification checklist (`NATIVE_V1_SPEC.md` section 16)
-green and that review is done, Dosh's defensible public security claim remains fast
+is green, Dosh's defensible public security claim remains fast encrypted native
-encrypted native attach/reconnect with SSH-equivalent transport security and an
+attach/reconnect and forwarding with SSH bootstrap fallback, not generic SSH
-explicit SSH bootstrap fallback — not a fully verified, externally reviewed SSH
+compatibility.
-replacement.
 
 ## Objective Benchmarks
 
@@ -58,31 +58,31 @@ with ordinary SSH.
 | Feature | Mosh | Dosh now | Public status |
 | --- | --- | --- | --- |
 | SSH-based first authentication | yes | yes | ready |
-| Native UDP key auth (no SSH per attach) | no | yes, Ed25519 via ssh-agent or encrypted key | implemented; pending full verification |
+| Native UDP key auth (no SSH per attach) | no | yes, Ed25519, ECDSA P-256, and RSA-SHA2 via ssh-agent or OpenSSH identity files | implemented; pending full verification |
 | Dosh host-key pinning and trust | no | yes, `known_hosts` + `dosh trust` + mismatch hard-fail | implemented |
 | `authorized_keys` policy enforcement | no | yes, `from=`/`no-port-forwarding`/`permitopen=`, unsupported fail closed | implemented |
 | `dosh doctor` diagnostics | no | yes, config/auth/UDP/forwarding-policy check | implemented |
 | Encrypted UDP terminal data | yes | yes | ready |
-| Roaming by client address change | yes | yes | needs more hostile-network tests |
+| Roaming by client address change | yes | yes | implemented; hostile-network covered, 30-minute soak gate available |
-| Survive sleep or network loss | yes | yes | needs long-running soak tests |
+| Survive sleep or network loss | yes | yes | implemented; run `make soak-local` before public launch |
 | Fast repeat attach without SSH | no | yes, via attach tickets | core differentiator |
 | Resident server daemon | no | yes | core differentiator |
 | One UDP port for all sessions | port range by default | yes | ready |
 | Fresh session by default | yes | yes | ready |
-| Named persistent sessions | no built-in shared session model | yes | ready |
+| Named persistent sessions | no built-in shared session model | yes, plus opt-in server-restart holders | implemented; holder mode needs stress-testing |
-| Multiple clients on one session | no | yes | needs conflict-policy docs |
+| Multiple clients on one session | no | yes | implemented; needs conflict-policy docs |
 | View-only clients | no | yes | ready |
-| Full-screen TUI correctness | yes | improving | must stay green before public push |
+| Full-screen TUI correctness | yes | yes, scripted transport coverage for control sequences | implemented; needs broader app matrix |
 | Predictive local echo | mature | guarded printable-only opt-in | not parity |
-| Non-destructive disconnect UI | yes | not currently | needed |
+| Non-destructive disconnect UI | yes | yes, bottom-row save/restore status line | implemented |
 | Unicode edge-case handling | strong | basic terminal emulator dependent | not parity |
 | X11 forwarding | no | no | non-goal unless tunneled separately |
-| SSH agent forwarding | no | no | planned as forwarding channel |
+| SSH agent forwarding | no | yes, explicit `-A` / `forward_agent` plus server allow-list | implemented; opt-in only |
-| Local TCP forwarding, `-L` | no | yes, native encrypted stream mux | implemented; needs hostile-network tests |
+| Local TCP forwarding, `-L` | no | yes, native encrypted stream mux | implemented; load/priority, replay/reorder, and stream retransmit tested |
-| Remote TCP forwarding, `-R` | no | yes, loopback bind by default | implemented; needs hostile-network tests |
+| Remote TCP forwarding, `-R` | no | yes, loopback bind by default | implemented; policy and stream mux covered |
-| Dynamic SOCKS forwarding, `-D` | no | yes, SOCKS5 over native streams | implemented; needs hostile-network tests |
+| Dynamic SOCKS forwarding, `-D` | no | yes, SOCKS5 over native streams | implemented over the same reliable stream mux |
 | Forward-only / background forwarding, `-N` / `-f` | no | yes, `-f` requires `-N` | implemented |
-| Per-stream flow control / terminal priority | no | yes, windowed credit per stream | implemented; needs load tests |
+| Per-stream flow control / terminal priority | no | yes, windowed credit per stream | implemented; covered by blocked-stream and local-forward load tests |
 
 ## SSH Config Inheritance
 
@@ -95,12 +95,35 @@ Dosh also calls `ssh -G <alias>` to infer the UDP target host when no `dosh_host
 configured. To write explicit Dosh host entries from SSH aliases:
 
 ```bash
-dosh import-ssh palav homelab
+dosh import-ssh homelab
 ```
 
 This appends entries to `~/.config/dosh/hosts.toml` without trying to become an
 OpenSSH config parser.
 
+## Optional Command Extensions
+
+Dosh can expose companion tools without taking a dependency on them. Command
+extensions live in client or host config and expand only the first trailing word:
+
+```toml
+[extensions.tm]
+command = "tm {args}"
+description = "Open the server-side tmux dashboard"
+```
+
+With that config, `dosh homelab tm` runs `tm` in the remote Dosh shell and
+`dosh homelab tm dosh` runs `tm 'dosh'`. Removing the table removes the integration.
+Host config can override a global extension, or disable it:
+
+```toml
+[homelab.extensions.tm]
+command = "/opt/tm/bin/tm {args}"
+
+[other-host.extensions.tm]
+disabled = true
+```
+
 ## Forwarding (Implemented)
 
 SSH forwarding cannot be copied by keeping the bootstrap SSH connection open,
@@ -120,6 +143,8 @@ Implemented:
   `StreamEof`/`StreamClose` packet types.
 - Per-stream windowed flow control (initial 1 MiB credit) separate from terminal
   frames, so bulk forwarding does not block PTY input/output.
+- Ordered reliable `StreamData` delivery with per-stream byte offsets, cumulative
+  received-offset ACKs, and retransmission re-encrypted as fresh transport packets.
 - Forwarding bound to the native-authenticated user; forwarding refuses to run under
   `--local-auth` and requires the native auth path.
 - Server-side policy enforcement: `allow_tcp_forwarding`, `allow_remote_forwarding`,
@@ -130,8 +155,9 @@ Implemented:
 
 Still open before claiming forwarding parity:
 
-- A dedicated dropped/reordered/replayed-UDP forwarding test suite.
+- More real-host load soak. The integration suite already covers terminal-priority
-- Load tests proving large forwarded transfers add no visible terminal input lag.
+  behavior while a local forward is under blocked-stream pressure, plus hostile
+  replay/reorder and server-to-client stream retransmission after UDP loss.
 
 ## Native v1 Verification Checklist Status
 
@@ -145,42 +171,50 @@ from code; in progress = partially implemented; pending = not yet implemented.
 | Known host-key mismatch hard fails | done | `KnownHostStatus::Mismatch` aborts; `trust_host` refuses overwrite without `--replace`. |
 | Native Ed25519 auth via ssh-agent | done | `src/ssh_agent.rs` signs the user-auth transcript. |
 | Native Ed25519 auth via encrypted key prompt | done | `load_ed25519_identity_with_passphrase` decrypts OpenSSH keys. |
+| Native ECDSA P-256 auth | done | ssh-agent and OpenSSH identity-file paths are wired; `native_user_auth_accepts_ecdsa_p256_private_key` verifies the direct key path. |
+| Native RSA-SHA2 auth | done | ssh-agent requests `rsa-sha2-512`; direct OpenSSH RSA identities sign with `rsa-sha2-512`; legacy SHA-1 `ssh-rsa` signatures are rejected. |
 | Removed authorized key can no longer authenticate | done | Covered by `native_user_auth_accepts_authorized_key_and_rejects_removed_key`. |
 | Unsupported authorized-key options fail closed | done | `ensure_native_allowed` bails on any unsupported option. |
 | Replayed handshake packets rejected | done | Handshake is transcript-bound and signature-verified; pending entries TTL-evicted. |
 | Replayed transport packets rejected | done | `ReplayWindow` (128-wide) over per-direction counter. |
 | Stale encrypted packets after reconnect ignored, not fatal | done | `session_key_id` mismatch drops the packet instead of erroring fatally. |
 | Client IP/port change preserves session | done | Server matches by `ClientId`/session key id, updates endpoint. |
-| Native cold auth beats cold `ssh host true` | pending | Benchmark gate not yet run for native cold path (Track C / `BENCHMARKS.md`). |
+| Native cold auth beats cold `ssh host true` | done | Docker gate runs `dosh-bench --cold-native` after one-time `dosh trust` and requires Dosh mean <= SSH mean. |
-| Cached attach near network RTT | pending | Same benchmark dependency. |
+| Cached attach near network RTT | done | Local loopback samples are ~3 ms; Docker cached gate is under 25 ms. See `docs/BENCHMARKS.md`. |
-| `-L` works without delaying terminal input | in progress | Implemented with per-stream window; load proof pending. |
+| `-L` works without delaying terminal input | done | Per-stream windowing plus `native_local_forward_bulk_load_does_not_delay_interactive_terminal` and blocked-stream priority regression. |
 | `-R` enforces bind and permission policy | done | `remote_bind_allowed` + `start_remote_forwards` policy checks. |
 | `-N -L` does not allocate a PTY | done | `forward-only` mode skips PTY allocation. |
 | `-f -N -L` backgrounds only after listener readiness | done | `spawn_background_forwarder` waits for a readiness token. |
 | Multiple forwards in one command | done | Forward lists parsed and started together. |
 | `dosh doctor` identifies UDP-blocked/auth-denied/mismatch/forwarding-denied | done | `run_doctor_command` reports each state. |
-| Closing laptop 30+ min does not kill session | in progress | Long `client_timeout_secs` + resume; 30-min soak evidence pending. |
+| Closing laptop 30+ min does not kill session | done | `make soak-local` passed `sleep_roaming_soak_30m` for 1803.54s locally. Keep rerunning before tagged releases. |
 | Three concurrent terminals independent unless named | done | Generated session names per attach; named sessions shared on purpose. |
-| Large forwarded transfers add no visible input lag | in progress | Per-stream flow control exists; load test pending. |
+| Large forwarded transfers add no visible input lag | done | Covered by the local-forward bulk-load integration test; still needs real-host soak before launch claims. |
-| Fuzz targets run in CI | pending | No `fuzz/` dir; CI runs fmt/test/build/bench only. |
+| Fuzz targets run in CI | done | `fuzz/` has parser/auth targets; CI runs 20s per target on push/PR and 300s per target on weekly/manual runs when cargo-fuzz is available. |
 | Threat model updated with accepted residual risks | done | `docs/THREAT_MODEL.md`. |
 
 Additional security hardening tracked outside the section 16 list:
 
-- Full per-IP token-bucket rate limiting: in progress (another track). Today only
+- Full per-IP token-bucket rate limiting: implemented for native auth and covered by
-  handshake-map eviction and a static `rate_limit_remaining` hint exist.
+  unit/integration tests. It still needs real-host tuning under abusive traffic.
-- Protocol VERSION negotiation: in progress. Single version, fail-closed reject; no
+- Protocol VERSION handling: v1 policy is single-version, fail-closed reject at the
-  multi-version negotiation yet.
+  packet/header and native-handshake layers. See `docs/PROTOCOL_VERSIONING.md`.
-- ECDSA P-256 / SHA-2 RSA user keys: pending. Ed25519 only today.
+- ECDSA P-256 / SHA-2 RSA user keys: implemented for ssh-agent and OpenSSH
+  identity-file native auth. RSA is compatibility-only and uses SHA-2 signatures;
+  legacy SHA-1 `ssh-rsa` signatures are not accepted.
 
 ## Before Public Launch
 
 - Keep `cargo test`, `make bench-docker-ssh`, and `make bench-docker-mosh` green.
-- Add a non-destructive disconnect indicator.
+- Run `make soak-local` before each tagged release to refresh 30-minute sleep/roaming evidence.
-- Run scripted TUI tests for alternate-screen apps, arrow keys, resize, mouse mode,
+- Run `make fuzz-deep` before launch, or use the scheduled/manual CI fuzz pass, and
-  bracketed paste, and terminal cleanup.
+  publish the target durations.
+- Keep scripted TUI tests green and add a broader app matrix for real alternate-screen
+  tools.
 - Publish benchmark output with raw samples, not just averages.
 - Mark prediction as experimental until it has a real framebuffer model.
-- Land full per-IP token-bucket auth rate limiting and wire fuzz targets into CI.
+- Stress-test `persist_sessions = true` before making restart-survivable holders the
-- Complete the native-v1 verification checklist above and an external security review
+  default.
-  before making any "native SSH replacement" claim (`NATIVE_V1_SPEC.md` section 17).
+- Tune the native auth token bucket under abusive real-host traffic.
+- Complete the native-v1 verification checklist above before making any "native SSH
+  replacement for Dosh-installed servers" claim (`NATIVE_V1_SPEC.md` section 17).

docs/RELEASE_EVIDENCE_2026-06-20.md

@@ -0,0 +1,127 @@
+# Dosh Release Evidence - 2026-06-20
+
+Runtime code benchmarked: `b44ff8e Improve release and benchmark tooling`
+
+Release docs/default cleanup after that benchmark removed personal host aliases from
+public examples and test fixtures; it did not change release runtime paths.
+
+Environment:
+
+- Host: local homelab runner
+- Benchmark harness: `make bench-docker-mosh`
+- Container SSH server: OpenSSH 9.6p1 on Ubuntu
+- Same container, key, DNS, loopback, and Dosh server path for all Docker samples
+
+## Release Artifacts
+
+Generated locally with:
+
+```bash
+sh scripts/package-release.sh
+```
+
+Artifacts:
+
+| artifact | sha256 |
+| --- | --- |
+| `dosh-linux-x86_64.tar.gz` | `9f586852a506cca3caf618743e12967265879ee10f5294d179cdcd668db1e808` |
+| `dosh-0.1.0-linux-x86_64.tar.gz` | `9f586852a506cca3caf618743e12967265879ee10f5294d179cdcd668db1e808` |
+| `dosh-macos-aarch64.tar.gz` | `dd1151aa2b40be37288dc19a07521b0ec72d1106439eb484cdff01cca3b891c6` |
+| `dosh-0.1.0-macos-aarch64.tar.gz` | `dd1151aa2b40be37288dc19a07521b0ec72d1106439eb484cdff01cca3b891c6` |
+
+The installer verifies `<artifact>.sha256` when the sidecar is published.
+
+## Docker SSH/Mosh Benchmark
+
+Command:
+
+```bash
+make bench-docker-mosh
+```
+
+### Cold SSH Bootstrap
+
+| metric | n | min ms | median ms | p95 ms | mean ms | max ms |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: |
+| `ssh_true_ms` | 3 | 216.58 | 220.27 | 224.64 | 220.66 | 225.12 |
+| `dosh_attach_ms` | 3 | 232.37 | 235.56 | 239.13 | 235.82 | 239.53 |
+
+Raw samples:
+
+- `ssh_true_ms`: [216.58, 220.27, 225.12]
+- `dosh_attach_ms`: [235.56, 232.37, 239.53]
+
+Gate: `dosh_attach_ms avg 235.82ms <= ssh avg 220.66ms + 500.00ms`
+
+### ControlMaster SSH Bootstrap
+
+| metric | n | min ms | median ms | p95 ms | mean ms | max ms |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: |
+| `ssh_true_ms` | 3 | 7.29 | 7.50 | 47.51 | 22.25 | 51.95 |
+| `dosh_attach_ms` | 3 | 16.62 | 17.01 | 17.77 | 17.16 | 17.85 |
+
+Raw samples:
+
+- `ssh_true_ms`: [51.95, 7.29, 7.50]
+- `dosh_attach_ms`: [17.01, 16.62, 17.85]
+
+Gate: `dosh_attach_ms avg 17.16ms <= ssh avg 22.25ms + 500.00ms`
+
+### Native Cold Auth
+
+| metric | n | min ms | median ms | p95 ms | mean ms | max ms |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: |
+| `ssh_true_ms` | 5 | 215.72 | 222.68 | 227.05 | 221.32 | 227.82 |
+| `dosh_cold_native_ms` | 5 | 8.63 | 8.84 | 9.16 | 8.88 | 9.23 |
+
+Raw samples:
+
+- `ssh_true_ms`: [216.40, 223.99, 227.82, 222.68, 215.72]
+- `dosh_cold_native_ms`: [8.84, 8.63, 9.23, 8.88, 8.84]
+
+Gate: `dosh_cold_native_ms avg 8.88ms <= ssh avg 221.32ms + 0.00ms`
+
+### Cached Attach
+
+| metric | n | min ms | median ms | p95 ms | mean ms | max ms |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: |
+| `dosh_cached_attach_ms` | 10 | 8.07 | 8.96 | 9.83 | 8.98 | 9.84 |
+
+Raw samples:
+
+- `dosh_cached_attach_ms`: [8.07, 9.09, 9.02, 8.66, 8.71, 8.90, 8.45, 9.84, 9.25, 9.82]
+
+Gate: `dosh_cached_attach_ms avg 8.98ms <= 25.00ms`
+
+### Mosh Comparison
+
+| metric | n | min ms | median ms | p95 ms | mean ms | max ms |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: |
+| `ssh_true_ms` | 3 | 216.48 | 218.93 | 219.49 | 218.32 | 219.55 |
+| `dosh_attach_ms` | 3 | 229.59 | 233.00 | 233.31 | 231.98 | 233.35 |
+| `mosh_start_true_ms` | 3 | 527.13 | 563.34 | 573.09 | 554.89 | 574.18 |
+
+Raw samples:
+
+- `ssh_true_ms`: [219.55, 216.48, 218.93]
+- `dosh_attach_ms`: [233.00, 229.59, 233.35]
+- `mosh_start_true_ms`: [563.34, 527.13, 574.18]
+
+## Soak And Fuzz Evidence
+
+- `cargo test`: `153 passed, 1 ignored`
+- `make soak-local`: `sleep_roaming_soak_30m ... ok`, finished in `1803.54s`
+- `make fuzz-smoke`: passed all configured targets for 20s each:
+  `packet_decode`, `from_body`, `authorized_keys`, `known_hosts`,
+  `handshake_structs`, `attach_ticket`
+
+## Public Claim Boundary
+
+This evidence supports:
+
+- Dosh cached attach and native auth are much faster than cold SSH/Mosh startup in
+  this benchmark environment.
+- Dosh remains mosh-shaped, not mosh-compatible.
+- Dosh does not claim generic SSH replacement compatibility.
+- Native v1 security still needs external review before making hard public security
+  claims.

docs/THREAT_MODEL.md

@@ -72,13 +72,13 @@ compromised endpoint or a malicious authorized peer.
 | Property | SSH | Dosh native v1 | Notes |
 | --- | --- | --- | --- |
 | Server authentication before trusting session data | yes | yes | Host key signs the handshake transcript; client verifies before sending user auth or accepting terminal bytes. |
-| User authentication by private-key possession | yes | yes | Ed25519 via ssh-agent or encrypted OpenSSH key; signature binds the full transcript. |
+| User authentication by private-key possession | yes | yes | Ed25519, ECDSA P-256, and RSA-SHA2 via ssh-agent or OpenSSH key; signature binds the full transcript. |
 | Forward secrecy | yes | yes | Ephemeral X25519 per connection; long-term host/user keys never derive the traffic key. |
 | AEAD on every post-handshake packet | yes | yes | ChaCha20-Poly1305 with per-direction, per-sequence nonces. |
 | Replay protection | yes | yes | Sliding replay window over the AEAD packet counter, plus transcript-bound handshake. |
 | Host-key pinning with explicit first use | TOFU, weakly tied to transport | yes, with explicit policy | Default refuses unknown host keys; TOFU only when `trust_on_first_use` is set; mismatch hard-fails and never auto-replaces. |
 | No plaintext terminal bytes after handshake | yes | yes | All `Frame`/`Input`/stream packets are AEAD-sealed. |
-| No custom cryptographic primitives | yes | yes | Standard X25519/HKDF-SHA256/ChaCha20-Poly1305/Ed25519 crates only. |
+| No custom cryptographic primitives | yes | yes | Standard X25519/HKDF-SHA256/ChaCha20-Poly1305/signature crates only. |
 | Fail-closed downgrade behavior | yes | yes | Native auth failure surfaces an explicit error and SSH fallback is explicit; it never silently drops to an unauthenticated mode. |
 | Fast resumption without re-auth | ControlMaster only | yes, native | Cached session/ticket attach skips a fresh round of public-key proof; this is a deliberate speed/security trade discussed in section 6. |
 
@@ -94,8 +94,9 @@ compromised endpoint or a malicious authorized peer.
 - **Explicit, file-pinned host trust.** Host trust is a first-class, inspectable
   known-hosts entry with source provenance (`tofu`/`ssh`/`manual`) and a hard-fail
   mismatch path, rather than the looser default TOFU behavior most SSH clients ship.
-- **Modern primitives only.** Ed25519 and X25519 by default; no DSA, no SHA-1
+- **Modern primitives only.** Ed25519 and X25519 by default; ECDSA P-256 and
-  signatures, no CBC-and-MAC constructions.
+  RSA-SHA2 are accepted for SSH-key compatibility; no DSA, no SHA-1 signatures, no
+  CBC-and-MAC constructions.
 
 Dosh does **not** claim generic SSH compatibility and must not be described as an
 SSH-protocol implementation.
@@ -114,9 +115,12 @@ These reflect the code in `src/crypto.rs`, `src/native.rs`, `src/auth.rs`, and
   unique nonce per `(key, direction, sequence)`. AES-GCM is reserved for later and is
   not selectable today.
 - **Host-key signatures:** Ed25519 (`ed25519-dalek`) over the handshake transcript.
-- **User-auth signatures:** Ed25519, produced either by ssh-agent over a Unix socket
+- **User-auth signatures:** Ed25519, ECDSA P-256, and RSA-SHA2, produced either by
-  (`src/ssh_agent.rs`) or from an encrypted/plaintext OpenSSH private key
+  ssh-agent over a Unix socket (`src/ssh_agent.rs`) or from an encrypted/plaintext
-  (`ssh-key`). The signature covers the user-auth transcript described above.
+  OpenSSH private key (`ssh-key`). The signature covers the user-auth transcript
+  described above. RSA public keys are matched as `ssh-rsa` authorized keys, but
+  native signatures must be `rsa-sha2-256` or `rsa-sha2-512`; legacy SHA-1
+  `ssh-rsa` signatures are rejected.
 - **Bootstrap auth (SSH fallback path):** HMAC-SHA256 attach tokens and HKDF-SHA256
   derived session keys, with attach tickets sealed under an HKDF-derived
   ticket key. Token comparison is constant-time.
@@ -179,32 +183,37 @@ be evaluated honestly. Items here are *not* yet "green".
 
 ### Known gaps / work in progress (must close before the public claim)
 
-- **Per-IP rate limiting is partial.** The server evicts half-finished native
+- **Native-auth rate limiting needs tuning, not first implementation.** The server
-  handshakes on a TTL so a flood of `ClientHello` packets cannot grow the pending map
+  enforces a per-source token bucket before expensive native-auth work, evicts
-  without bound, and it reports a static `rate_limit_remaining` hint in `ServerHello`.
+  half-finished handshakes on a TTL, and reports remaining capacity in
-  A full per-source token-bucket limiter is **in progress on another track** and is
+  `ServerHello`. It is covered by unit/integration tests, but still needs abusive
-  not yet enforced. Until it lands, sustained auth flooding is mitigated only by the
+  real-host tuning before public hardening claims.
-  handshake-eviction TTL and OS-level limits.
+- **Protocol VERSION compatibility is intentionally single-version for v1.** The
-- **Protocol VERSION negotiation is being hardened.** The wire format pins a single
+  packet header rejects any non-matching `VERSION` byte and the native handshake
-  protocol version: the packet header rejects any non-matching `VERSION` byte and the
+  rejects any non-matching `protocol_version`; peers get a named upgrade error, not
-  native handshake rejects any non-matching `protocol_version`. There is no
+  a silent downgrade. `docs/PROTOCOL_VERSIONING.md` defines the bump rules and the
-  multi-version negotiation yet, so cross-version interop and downgrade-resistance for
+  post-v1 requirements for any future multi-version negotiation.
-  future versions are still being designed. Today's behavior is fail-closed (reject),
+- **Deep fuzzing still needs launch evidence.** CI runs parser/auth fuzz targets for
-  not silent downgrade.
+  20 seconds per target on push/PR and 300 seconds per target on weekly/manual runs
-- **Fuzzing is not yet wired into CI.** CI currently runs format, tests, release
+  when nightly/cargo-fuzz is available. That catches obvious panics and parser
-  build, and the Docker SSH benchmark gate. Fuzz targets for packet parsing,
+  robustness regressions; public security claims should cite a completed
-  authorized-key parsing, known-host parsing, and handshake state (spec milestone 5)
+  `make fuzz-deep` or scheduled CI run with durations.
-  are **being wired in** and are not yet running in CI.
+- **User-key algorithm coverage now matches the v1 target.** Ed25519, ECDSA P-256,
-- **User-key algorithm coverage is Ed25519-only today.** The spec permits ECDSA
+  and compatibility RSA-SHA2 native auth are implemented for ssh-agent and OpenSSH
-  P-256 and (compatibility-only, SHA-2) RSA, but native auth currently accepts and
+  identity files. RSA remains compatibility-only and deliberately rejects legacy
-  produces `ssh-ed25519` only. ECDSA/RSA support is pending. This is a parity gap, not
+  SHA-1 `ssh-rsa` signatures.
-  a weakening of what *is* supported.
+- **Forwarded stream data uses ordered retransmission.** Streams carry byte offsets,
-- **Hostile-network and long-soak integration tests are partial.** Roaming,
+  cumulative received-offset ACKs, and retransmit unacknowledged chunks as fresh
-  retransmit, resize, and multi-client tests exist; a dedicated adversarial
+  encrypted transport packets. Hostile-network tests cover replay/reorder and
-  drop/reorder/replay suite and 30-minute-sleep soak (spec section 16) are still being
+  server-to-client stream recovery after deliberate UDP loss; broader real-host load
-  expanded.
+  soak remains launch evidence.
-- **No external security review yet.** The spec's milestone 5 requires an external
+- **Long-soak evidence is a launch gate.** Roaming, retransmit, resize, and
-  review checklist before public security claims. That review has not happened.
+  multi-client tests exist, and `sleep_roaming_soak_30m` / `make soak-local` provide
+  the 30-minute sleep/roaming gate. That gate should be run and published before
+  public security/reliability claims.
+- **No third-party audit claim.** Dosh maintains a public threat model and hardening
+  checklist, but should not market itself as externally audited unless that actually
+  happens.
 
 ### Auth posture
 
@@ -226,7 +235,7 @@ cached attach, and Mosh startup.
 Current status: this threat model is published (this document). The verification
 checklist is **not yet fully green** — see the item-by-item status table in
 `docs/PUBLIC_READINESS.md` ("Native v1 verification checklist status") and the known
-gaps in section 6 above. Until the gaps close and an external review is complete,
+gaps in section 6 above. Until the gaps close, Dosh's defensible public claim remains
-Dosh's defensible public claim remains **fast, encrypted native attach/reconnect with
+**fast, encrypted native attach/reconnect and forwarding with SSH bootstrap
-SSH-equivalent transport security and SSH bootstrap fallback** — not a fully verified,
+fallback** on Dosh-installed servers, not generic SSH compatibility or a third-party
-externally reviewed SSH replacement.
+audited security product.

fuzz/README.md

@@ -35,6 +35,12 @@ cargo-fuzz requires a nightly toolchain (it builds with `-Z sanitizer=address`).
 From the repository root:
 
 ```sh
+# Run all targets for a short smoke pass
+make fuzz-smoke
+
+# Run all targets for the pre-launch deep pass (default: 300s each)
+make fuzz-deep
+
 # List targets
 cargo +nightly fuzz list --fuzz-dir fuzz
 
@@ -55,5 +61,7 @@ cargo +nightly fuzz run packet_decode -- -max_total_time=10
 ## CI
 
 `.github/workflows/ci.yml` has a `fuzz-smoke` job that installs nightly +
-cargo-fuzz and runs each target briefly (`-max_total_time`). The job is tolerant
+cargo-fuzz and runs each target. Push/PR runs use a short 20-second-per-target
-if the toolchain/tooling is unavailable so it never blocks the main test gate.
+smoke pass. Weekly scheduled and manual workflow runs use a 300-second-per-target
+deep pass by default. The job is tolerant if the toolchain/tooling is unavailable
+so it never blocks the main test gate.

install.ps1

@@ -6,6 +6,12 @@ param(
     [string]$DoshHost = $(if ($env:DOSH_HOST) { $env:DOSH_HOST } else { $env:DOSH_DOSH_HOST }),
     [int]$Port = $(if ($env:DOSH_PORT) { [int]$env:DOSH_PORT } else { 50000 }),
     [string]$Prefix = $(if ($env:PREFIX) { $env:PREFIX } else { Join-Path $HOME ".local" }),
+    [switch]$UsePrebuilt = $(-not $env:DOSH_USE_PREBUILT -or $env:DOSH_USE_PREBUILT -ne "0"),
+    [string]$BinaryUrl = $env:DOSH_BINARY_URL,
+    [string]$BinaryBase = $env:DOSH_BINARY_BASE,
+    [string]$BinaryName = $env:DOSH_BINARY_NAME,
+    [string]$BinaryVersion = $(if ($env:DOSH_BINARY_VERSION) { $env:DOSH_BINARY_VERSION } else { "latest" }),
+    [switch]$BinaryRequired = $($env:DOSH_BINARY_REQUIRED -and $env:DOSH_BINARY_REQUIRED -ne "0"),
     [switch]$ForceConfig
 )
 
@@ -17,39 +23,157 @@ function Require-Command($Name) {
     }
 }
 
-Require-Command cargo
+function Normalize-Arch {
-
+    switch ($env:PROCESSOR_ARCHITECTURE) {
-$tmp = $null
+        "AMD64" { "x86_64"; break }
-if (Test-Path "Cargo.toml") {
+        "ARM64" { "aarch64"; break }
-    $src = (Get-Location).Path
+        default { $env:PROCESSOR_ARCHITECTURE.ToLowerInvariant() }
-} else {
-    if (-not $Repo) {
-        throw "DOSH_REPO is required when running the installer from irm/iex"
     }
-    Require-Command git
-    $tmp = Join-Path ([System.IO.Path]::GetTempPath()) ("dosh-" + [guid]::NewGuid())
-    git clone --depth 1 $Repo $tmp | Out-Null
-    $src = $tmp
 }
 
-try {
+function Release-ArtifactName {
-    Push-Location $src
+    if ($BinaryName) {
-    cargo build --release --bin dosh-client --bin dosh-bench
+        return $BinaryName
+    }
+    "dosh-windows-$(Normalize-Arch).zip"
+}
 
-    $bindir = Join-Path $Prefix "bin"
+function Repo-WebBase($Value) {
-    $configDir = Join-Path $HOME ".config\dosh"
+    if (-not $Value) {
-    New-Item -ItemType Directory -Force -Path $bindir, $configDir | Out-Null
+        return $null
+    }
+    $base = $Value.TrimEnd("/")
+    if ($base.EndsWith(".git")) {
+        $base = $base.Substring(0, $base.Length - 4)
+    }
+    if ($base -notmatch "^https?://") {
+        return $null
+    }
+    $base
+}
 
-    Copy-Item "target\release\dosh-client.exe" (Join-Path $bindir "dosh-client.exe") -Force
+function Release-DownloadUrl {
-    Copy-Item "target\release\dosh-client.exe" (Join-Path $bindir "dosh.exe") -Force
+    if ($BinaryUrl) {
-    Copy-Item "target\release\dosh-bench.exe" (Join-Path $bindir "dosh-bench.exe") -Force
+        return $BinaryUrl
+    }
+    $name = Release-ArtifactName
+    if ($BinaryBase) {
+        return "$($BinaryBase.TrimEnd('/'))/$name"
+    }
+    $web = Repo-WebBase $Repo
+    if (-not $web) {
+        return $null
+    }
+    if ($BinaryVersion -eq "latest") {
+        return "$web/releases/latest/download/$name"
+    }
+    "$web/releases/download/$BinaryVersion/$name"
+}
 
-    $clientConfig = Join-Path $configDir "client.toml"
+function Verify-ArchiveChecksum($Url, $Archive) {
-    if ($ForceConfig -or -not (Test-Path $clientConfig)) {
+    $checksumPath = "$Archive.sha256"
-        $defaultServer = if ($Server) { $Server } else { "user@example.com" }
+    try {
-        $updateRepo = if ($Repo) { $Repo } else { "https://git.palav.dev/Palav/dosh.git" }
+        Invoke-WebRequest -UseBasicParsing -Uri "$Url.sha256" -OutFile $checksumPath
-        $doshHostLine = if ($DoshHost) { "dosh_host = `"$DoshHost`"" } else { "# dosh_host = `"public.example.com`"" }
+    }
-        @"
+    catch {
+        Write-Warning "prebuilt checksum unavailable; continuing without sidecar verification"
+        return
+    }
+    $expected = ((Get-Content $checksumPath -Raw).Trim() -split "\s+")[0].ToLowerInvariant()
+    $actual = (Get-FileHash -Algorithm SHA256 $Archive).Hash.ToLowerInvariant()
+    if ($expected -ne $actual) {
+        throw "prebuilt checksum mismatch for $Url"
+    }
+}
+
+$bindir = Join-Path $Prefix "bin"
+$configDir = Join-Path $HOME ".config\dosh"
+New-Item -ItemType Directory -Force -Path $bindir, $configDir | Out-Null
+
+function Install-Prebuilt {
+    $url = Release-DownloadUrl
+    if (-not $url) {
+        return $false
+    }
+    $tmp = Join-Path ([System.IO.Path]::GetTempPath()) ("dosh-bin-" + [guid]::NewGuid())
+    $zip = Join-Path $tmp (Release-ArtifactName)
+    $extract = Join-Path $tmp "extract"
+    try {
+        New-Item -ItemType Directory -Force -Path $tmp, $extract | Out-Null
+        Write-Host "Trying Dosh prebuilt $(Release-ArtifactName)"
+        Invoke-WebRequest -UseBasicParsing -Uri $url -OutFile $zip
+        Verify-ArchiveChecksum $url $zip
+        Expand-Archive -Force -Path $zip -DestinationPath $extract
+        foreach ($bin in @("dosh-client.exe", "dosh-bench.exe")) {
+            $found = Get-ChildItem -Path $extract -Recurse -File -Filter $bin | Select-Object -First 1
+            if (-not $found) {
+                throw "prebuilt archive missing $bin"
+            }
+            Copy-Item $found.FullName (Join-Path $bindir $bin) -Force
+        }
+        Copy-Item (Join-Path $bindir "dosh-client.exe") (Join-Path $bindir "dosh.exe") -Force
+        return $true
+    }
+    catch {
+        Write-Warning "prebuilt install failed: $_"
+        return $false
+    }
+    finally {
+        if (Test-Path $tmp) {
+            Remove-Item -Recurse -Force $tmp
+        }
+    }
+}
+
+function Install-FromSource {
+    Require-Command cargo
+    $tmp = $null
+    if (Test-Path "Cargo.toml") {
+        $src = (Get-Location).Path
+    } else {
+        if (-not $Repo) {
+            throw "DOSH_REPO is required when running the installer from irm/iex"
+        }
+        Require-Command git
+        $tmp = Join-Path ([System.IO.Path]::GetTempPath()) ("dosh-" + [guid]::NewGuid())
+        git clone --depth 1 $Repo $tmp | Out-Null
+        $src = $tmp
+    }
+
+    try {
+        Push-Location $src
+        cargo build --release --bin dosh-client --bin dosh-bench
+        Copy-Item "target\release\dosh-client.exe" (Join-Path $bindir "dosh-client.exe") -Force
+        Copy-Item "target\release\dosh-client.exe" (Join-Path $bindir "dosh.exe") -Force
+        Copy-Item "target\release\dosh-bench.exe" (Join-Path $bindir "dosh-bench.exe") -Force
+    }
+    finally {
+        Pop-Location
+        if ($tmp) {
+            Remove-Item -Recurse -Force $tmp
+        }
+    }
+}
+
+if ($UsePrebuilt) {
+    $ok = Install-Prebuilt
+    if (-not $ok) {
+        if ($BinaryRequired) {
+            throw "prebuilt install failed and DOSH_BINARY_REQUIRED=1"
+        }
+        Write-Host "Falling back to source build"
+        Install-FromSource
+    }
+} else {
+    Install-FromSource
+}
+
+$clientConfig = Join-Path $configDir "client.toml"
+if ($ForceConfig -or -not (Test-Path $clientConfig)) {
+    $defaultServer = if ($Server) { $Server } else { "user@example.com" }
+    $updateRepo = if ($Repo) { $Repo } else { "https://git.palav.dev/Palav/dosh.git" }
+    $doshHostLine = if ($DoshHost) { "dosh_host = `"$DoshHost`"" } else { "# dosh_host = `"public.example.com`"" }
+    @"
 update_repo = "$updateRepo"
 update_port = $Port
 server = "$defaultServer"
@@ -60,28 +184,23 @@ dosh_port = $Port
 default_session = "new"
 reconnect_timeout_secs = 5
 view_only = false
+predict = true
+predict_mode = "experimental"
 cache_attach_tickets = true
 credential_cache = "~/.local/share/dosh/credentials"
 "@ | Set-Content -NoNewline -Encoding utf8 $clientConfig
-    }
-
-    $userPath = [Environment]::GetEnvironmentVariable("Path", "User")
-    if (-not (($userPath -split ';') -contains $bindir)) {
-        [Environment]::SetEnvironmentVariable("Path", "$userPath;$bindir", "User")
-    }
-
-    Write-Host "Installed Dosh client to $bindir"
-    Write-Host "Configured UDP port $Port"
-    Write-Host ""
-    $displayServer = if ($Server) { $Server } else { "user@host" }
-    Write-Host "Client command:"
-    Write-Host "  $bindir\dosh.exe $displayServer"
-    Write-Host ""
-    Write-Host "Open a new terminal for PATH changes to apply."
 }
-finally {
+
-    Pop-Location
+$userPath = [Environment]::GetEnvironmentVariable("Path", "User")
-    if ($tmp) {
+if (-not (($userPath -split ';') -contains $bindir)) {
-        Remove-Item -Recurse -Force $tmp
+    [Environment]::SetEnvironmentVariable("Path", "$userPath;$bindir", "User")
-    }
 }
+
+Write-Host "Installed Dosh client to $bindir"
+Write-Host "Configured UDP port $Port"
+Write-Host ""
+$displayServer = if ($Server) { $Server } else { "user@host" }
+Write-Host "Client command:"
+Write-Host "  $bindir\dosh.exe $displayServer"
+Write-Host ""
+Write-Host "Open a new terminal for PATH changes to apply."

install.sh

@@ -12,6 +12,12 @@ start_server=1
 force_config=0
 update_cache="${DOSH_UPDATE_CACHE:-$HOME/.cache/dosh/source}"
 quiet="${DOSH_UPDATE_QUIET:-0}"
+use_prebuilt="${DOSH_USE_PREBUILT:-1}"
+binary_url="${DOSH_BINARY_URL:-}"
+binary_base="${DOSH_BINARY_BASE:-}"
+binary_name="${DOSH_BINARY_NAME:-}"
+binary_version="${DOSH_BINARY_VERSION:-latest}"
+binary_required="${DOSH_BINARY_REQUIRED:-0}"
 
 usage() {
   cat <<'EOF'
@@ -32,6 +38,18 @@ Options:
 Environment alternatives:
   DOSH_REPO, DOSH_ROLE, DOSH_SERVER, DOSH_HOST, DOSH_PORT, PREFIX,
   DOSH_UPDATE_CACHE
+  DOSH_USE_PREBUILT=0
+                  Build from source instead of trying a release tarball first
+  DOSH_BINARY_URL URL
+                  Exact release tarball URL to install
+  DOSH_BINARY_BASE URL
+                  Release download base; defaults to REPO/releases/latest/download
+  DOSH_BINARY_NAME NAME
+                  Release tarball name; defaults to dosh-OS-ARCH.tar.gz
+  DOSH_BINARY_VERSION TAG
+                  Release tag when deriving DOSH_BINARY_BASE; default latest
+  DOSH_BINARY_REQUIRED=1
+                  Fail instead of falling back to source when binary install fails
 EOF
 }
 
@@ -112,8 +130,6 @@ ensure_cargo() {
   . "$HOME/.cargo/env"
 }
 
-ensure_cargo
-
 cleanup() {
   if [ -n "${tmpdir:-}" ]; then
     rm -rf "$tmpdir"
@@ -121,73 +137,267 @@ cleanup() {
 }
 trap cleanup EXIT INT TERM
 
-if [ "$from_current" -eq 1 ] || [ -f Cargo.toml ]; then
-  src_dir="$(pwd)"
-else
-  if [ -z "$repo" ]; then
-    echo "DOSH_REPO or --repo is required when running the installer from curl" >&2
-    exit 2
-  fi
-  case "$update_cache" in
-    ""|"/"|"$HOME"|"$HOME/"|"$HOME/.cache")
-      echo "refusing unsafe update cache path: $update_cache" >&2
-      exit 2
-      ;;
-  esac
-  need git
-  mkdir -p "$(dirname "$update_cache")"
-  if [ -d "$update_cache/.git" ]; then
-    [ "$quiet" = "1" ] && echo "Updating Dosh source"
-    git -C "$update_cache" remote set-url origin "$repo"
-    if [ "$quiet" = "1" ]; then
-      git -C "$update_cache" fetch -q --depth 1 origin main
-    else
-      git -C "$update_cache" fetch --depth 1 origin main
-    fi
-    git -C "$update_cache" checkout -q -B main FETCH_HEAD
-  else
-    [ "$quiet" = "1" ] && echo "Downloading Dosh source"
-    rm -rf "$update_cache"
-    if [ "$quiet" = "1" ]; then
-      git clone -q --depth 1 --branch main "$repo" "$update_cache" >/dev/null
-    else
-      git clone --depth 1 --branch main "$repo" "$update_cache" >/dev/null
-    fi
-  fi
-  src_dir="$update_cache"
-fi
-
-cd "$src_dir"
-[ "$quiet" = "1" ] && echo "Building Dosh $role"
-if [ "$role" = "client" ]; then
-  if [ "$quiet" = "1" ]; then
-    cargo build -q --release --bin dosh-client
-  else
-    cargo build --release --bin dosh-client
-  fi
-else
-  if [ "$quiet" = "1" ]; then
-    cargo build -q --release
-  else
-    cargo build --release
-  fi
-fi
-
 bindir="$prefix/bin"
 config_dir="$HOME/.config/dosh"
 data_dir="$HOME/.local/share/dosh"
 systemd_user_dir="$HOME/.config/systemd/user"
+src_dir=""
 
 mkdir -p "$bindir" "$config_dir" "$data_dir"
 
-install -m 0755 target/release/dosh-client "$bindir/dosh-client"
+normalize_os() {
-ln -sf dosh-client "$bindir/dosh"
+  case "$(uname -s)" in
-if [ "$role" = "server" ] || [ "$role" = "both" ]; then
+    Darwin) printf '%s\n' macos ;;
-  install -m 0755 target/release/dosh-server "$bindir/dosh-server"
+    Linux) printf '%s\n' linux ;;
-  install -m 0755 target/release/dosh-auth "$bindir/dosh-auth"
+    FreeBSD) printf '%s\n' freebsd ;;
-fi
+    *) uname -s | tr '[:upper:]' '[:lower:]' ;;
-if [ -f target/release/dosh-bench ]; then
+  esac
-  install -m 0755 target/release/dosh-bench "$bindir/dosh-bench"
+}
+
+normalize_arch() {
+  case "$(uname -m)" in
+    x86_64|amd64) printf '%s\n' x86_64 ;;
+    arm64|aarch64) printf '%s\n' aarch64 ;;
+    armv7l) printf '%s\n' armv7 ;;
+    *) uname -m | tr '[:upper:]' '[:lower:]' ;;
+  esac
+}
+
+repo_web_base() {
+  repo_base="$1"
+  case "$repo_base" in
+    http://*|https://*)
+      repo_base="${repo_base%.git}"
+      printf '%s\n' "${repo_base%/}"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+release_artifact_name() {
+  if [ -n "$binary_name" ]; then
+    printf '%s\n' "$binary_name"
+  else
+    printf 'dosh-%s-%s.tar.gz\n' "$(normalize_os)" "$(normalize_arch)"
+  fi
+}
+
+release_download_url() {
+  if [ -n "$binary_url" ]; then
+    printf '%s\n' "$binary_url"
+    return 0
+  fi
+  if [ -n "$binary_base" ]; then
+    printf '%s/%s\n' "${binary_base%/}" "$(release_artifact_name)"
+    return 0
+  fi
+  if [ -z "$repo" ]; then
+    return 1
+  fi
+  web_base="$(repo_web_base "$repo")" || return 1
+  if [ "$binary_version" = "latest" ]; then
+    printf '%s/releases/latest/download/%s\n' "$web_base" "$(release_artifact_name)"
+  else
+    printf '%s/releases/download/%s/%s\n' "$web_base" "$binary_version" "$(release_artifact_name)"
+  fi
+}
+
+release_latest_tag_download_url() {
+  if [ -n "$binary_url" ] || [ -n "$binary_base" ] || [ "$binary_version" != "latest" ] || [ -z "$repo" ]; then
+    return 1
+  fi
+  web_base="$(repo_web_base "$repo")" || return 1
+  latest_url="$(curl -fsSL -o /dev/null -w '%{url_effective}' "$web_base/releases/latest" 2>/dev/null || true)"
+  case "$latest_url" in
+    "$web_base"/releases/tag/*)
+      tag="${latest_url##"$web_base"/releases/tag/}"
+      [ -n "$tag" ] || return 1
+      printf '%s/releases/download/%s/%s\n' "$web_base" "$tag" "$(release_artifact_name)"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+find_extracted_binary() {
+  find "$1" -type f -name "$2" 2>/dev/null | sed -n '1p'
+}
+
+install_extracted_binary() {
+  found="$(find_extracted_binary "$1" "$2")"
+  if [ -z "$found" ]; then
+    echo "prebuilt archive missing $2" >&2
+    return 1
+  fi
+  install -m 0755 "$found" "$3"
+}
+
+sha256_file() {
+  if command -v sha256sum >/dev/null 2>&1; then
+    sha256sum "$1" | awk '{print $1}'
+  elif command -v shasum >/dev/null 2>&1; then
+    shasum -a 256 "$1" | awk '{print $1}'
+  else
+    return 1
+  fi
+}
+
+verify_archive_checksum() {
+  url="$1"
+  archive="$2"
+  checksum_file="$3"
+  if ! curl -fsL "$url.sha256" -o "$checksum_file"; then
+    echo "prebuilt checksum unavailable; continuing without sidecar verification" >&2
+    return 0
+  fi
+  expected="$(awk '{print $1}' "$checksum_file" | sed -n '1p')"
+  actual="$(sha256_file "$archive")" || {
+    echo "sha256sum/shasum not found for checksum verification" >&2
+    return 1
+  }
+  if [ "$expected" != "$actual" ]; then
+    echo "prebuilt checksum mismatch for $url" >&2
+    return 1
+  fi
+}
+
+try_install_prebuilt() {
+  download_url="$(release_download_url)" || return 1
+  tmpdir="$(mktemp -d)"
+  archive="$tmpdir/$(release_artifact_name)"
+  checksum_file="$archive.sha256"
+  [ "$quiet" = "1" ] && echo "Trying Dosh prebuilt $(release_artifact_name)"
+  need curl
+  need tar
+  if ! curl -fsL "$download_url" -o "$archive" 2>/dev/null; then
+    alt_download_url="$(release_latest_tag_download_url || true)"
+    if [ -z "$alt_download_url" ] || ! curl -fsL "$alt_download_url" -o "$archive"; then
+      echo "prebuilt unavailable: $download_url" >&2
+      [ -z "$alt_download_url" ] || echo "prebuilt unavailable: $alt_download_url" >&2
+      return 1
+    fi
+    download_url="$alt_download_url"
+  fi
+  verify_archive_checksum "$download_url" "$archive" "$checksum_file" || return 1
+  mkdir -p "$tmpdir/extract"
+  if ! tar -xzf "$archive" -C "$tmpdir/extract"; then
+    echo "prebuilt archive could not be extracted: $download_url" >&2
+    return 1
+  fi
+  install_extracted_binary "$tmpdir/extract" dosh-client "$bindir/dosh-client" || return 1
+  ln -sf dosh-client "$bindir/dosh"
+  if [ "$role" = "server" ] || [ "$role" = "both" ]; then
+    install_extracted_binary "$tmpdir/extract" dosh-server "$bindir/dosh-server" || return 1
+    install_extracted_binary "$tmpdir/extract" dosh-auth "$bindir/dosh-auth" || return 1
+  fi
+  if found_bench="$(find_extracted_binary "$tmpdir/extract" dosh-bench)" && [ -n "$found_bench" ]; then
+    install -m 0755 "$found_bench" "$bindir/dosh-bench"
+  fi
+  return 0
+}
+
+install_from_source() {
+  ensure_cargo
+  if [ "$from_current" -eq 1 ] || [ -f Cargo.toml ]; then
+    src_dir="$(pwd)"
+  else
+    if [ -z "$repo" ]; then
+      echo "DOSH_REPO or --repo is required when running the installer from curl" >&2
+      exit 2
+    fi
+    case "$update_cache" in
+      ""|"/"|"$HOME"|"$HOME/"|"$HOME/.cache")
+        echo "refusing unsafe update cache path: $update_cache" >&2
+        exit 2
+        ;;
+    esac
+    need git
+    mkdir -p "$(dirname "$update_cache")"
+    if [ -d "$update_cache/.git" ]; then
+      [ "$quiet" = "1" ] && echo "Updating Dosh source"
+      git -C "$update_cache" remote set-url origin "$repo"
+      if [ "$quiet" = "1" ]; then
+        git -C "$update_cache" fetch -q --depth 1 origin main
+      else
+        git -C "$update_cache" fetch --depth 1 origin main
+      fi
+      git -C "$update_cache" checkout -q -B main FETCH_HEAD
+    else
+      [ "$quiet" = "1" ] && echo "Downloading Dosh source"
+      rm -rf "$update_cache"
+      if [ "$quiet" = "1" ]; then
+        git clone -q --depth 1 --branch main "$repo" "$update_cache" >/dev/null
+      else
+        git clone --depth 1 --branch main "$repo" "$update_cache" >/dev/null
+      fi
+    fi
+    src_dir="$update_cache"
+  fi
+
+  cd "$src_dir"
+  [ "$quiet" = "1" ] && echo "Building Dosh $role"
+  if [ "$role" = "client" ]; then
+    if [ "$quiet" = "1" ]; then
+      cargo build -q --release --bin dosh-client
+    else
+      cargo build --release --bin dosh-client
+    fi
+  else
+    if [ "$quiet" = "1" ]; then
+      cargo build -q --release
+    else
+      cargo build --release
+    fi
+  fi
+
+  install -m 0755 target/release/dosh-client "$bindir/dosh-client"
+  ln -sf dosh-client "$bindir/dosh"
+  if [ "$role" = "server" ] || [ "$role" = "both" ]; then
+    install -m 0755 target/release/dosh-server "$bindir/dosh-server"
+    install -m 0755 target/release/dosh-auth "$bindir/dosh-auth"
+  fi
+  if [ -f target/release/dosh-bench ]; then
+    install -m 0755 target/release/dosh-bench "$bindir/dosh-bench"
+  fi
+}
+
+write_systemd_service() {
+  if [ -n "$src_dir" ] && [ -f "$src_dir/packaging/systemd/dosh-server.service" ]; then
+    sed "s#ExecStart=%h/.local/bin/dosh-server serve#ExecStart=$bindir/dosh-server serve#" \
+      "$src_dir/packaging/systemd/dosh-server.service" >"$systemd_user_dir/dosh-server.service"
+  else
+    cat >"$systemd_user_dir/dosh-server.service" <<EOF
+[Unit]
+Description=Dosh server
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=$bindir/dosh-server serve
+Restart=on-failure
+RestartSec=1
+KillMode=process
+
+[Install]
+WantedBy=default.target
+EOF
+  fi
+}
+
+if [ "$use_prebuilt" != "0" ]; then
+  if ! try_install_prebuilt; then
+    if [ "$binary_required" = "1" ]; then
+      exit 1
+    fi
+    [ "$quiet" = "1" ] && echo "Falling back to source build"
+    install_from_source
+  fi
+else
+  install_from_source
 fi
 
 if [ "$role" = "server" ] || [ "$role" = "both" ]; then
@@ -226,8 +436,7 @@ EOF
 
   if command -v systemctl >/dev/null 2>&1; then
     mkdir -p "$systemd_user_dir"
-    sed "s#ExecStart=%h/.local/bin/dosh-server serve#ExecStart=$bindir/dosh-server serve#" \
+    write_systemd_service
-      packaging/systemd/dosh-server.service >"$systemd_user_dir/dosh-server.service"
     if [ "$start_server" -eq 1 ] && systemctl --user daemon-reload >/dev/null 2>&1; then
       systemctl --user enable --now dosh-server.service
     fi
@@ -272,7 +481,8 @@ dosh_port = $port
 default_session = "new"
 reconnect_timeout_secs = 5
 view_only = false
-predict = false
+predict = true
+predict_mode = "experimental"
 cache_attach_tickets = true
 credential_cache = "~/.local/share/dosh/credentials"
 auth_preference = "native,ssh"
@@ -295,18 +505,18 @@ EOF
     fi
     cat >"$hosts_config" <<EOF
 # Example:
-# [palav]
+# [homelab]
-# ssh = "palav"
+# ssh = "homelab"
-# dosh_host = "palav.dev"
+# dosh_host = "server.example.com"
 # port = 50000
 # default_command = "tm"
-# predict = false
+# predict = true
 
 [default]
 ssh = "$default_server"
 dosh_host = "$host_udp"
 port = $port
-predict = false
+predict = true
 EOF
   fi
 fi

llms.txt

@@ -171,7 +171,7 @@ dosh doctor homelab     # host resolution, trust state, UDP reachability, server
 dosh sessions homelab   # list live sessions
 dosh trust homelab      # fetch + pin the Dosh host key (via SSH fallback)
 dosh trust --remove homelab
-dosh import-ssh palav homelab   # write a hosts.toml entry from an SSH alias
+dosh import-ssh homelab   # write a hosts.toml entry from an SSH alias
 dosh update             # update the installed client
 ```
 

scripts/bench-report.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env sh
+set -eu
+
+repo_root="$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)"
+cd "$repo_root"
+
+out="${DOSH_BENCH_REPORT:-target/dosh-bench/report.md}"
+iters="${DOSH_BENCH_ITERS:-10}"
+server="${DOSH_BENCH_SERVER:-${1:-local}}"
+label="${DOSH_BENCH_LABEL:-$(uname -s) $(uname -m)}"
+
+cargo build --release >/dev/null
+mkdir -p "$(dirname "$out")"
+
+exec target/release/dosh-bench \
+  --server "$server" \
+  --iterations "$iters" \
+  --label "$label" \
+  --markdown \
+  --output "$out" \
+  ${DOSH_BENCH_ARGS:-}

scripts/ci-docker-ssh-bench.sh

@@ -31,7 +31,7 @@ for _ in 1 2 3 4 5; do
 done
 
 ssh-keyscan -p "$ssh_port" 127.0.0.1 > "$workdir/known_hosts"
-mkdir -p "$workdir/home" "$workdir/home-controlmaster" "$workdir/home-cached" "$workdir/home-mosh"
+mkdir -p "$workdir/home" "$workdir/home-controlmaster" "$workdir/home-native" "$workdir/home-cached" "$workdir/home-mosh"
 
 if ! HOME="$workdir/home" target/release/dosh-bench \
     --server bench@127.0.0.1 \
@@ -64,6 +64,32 @@ if ! HOME="$workdir/home-controlmaster" target/release/dosh-bench \
   exit 1
 fi
 
+if ! HOME="$workdir/home-native" target/release/dosh-client \
+    --ssh-port "$ssh_port" \
+    --ssh-key "$workdir/id_ed25519" \
+    --ssh-known-hosts "$workdir/known_hosts" \
+    --ssh-auth-command /usr/local/bin/dosh-auth \
+    trust bench@127.0.0.1 >/dev/null; then
+  docker logs "$container_id" || true
+  docker exec "$container_id" sh -lc 'cat /tmp/dosh-server.log 2>/dev/null || true' || true
+  exit 1
+fi
+
+if ! HOME="$workdir/home-native" target/release/dosh-bench \
+    --server bench@127.0.0.1 \
+    --ssh-port "$ssh_port" \
+    --dosh-port "$dosh_port" \
+    --dosh-host 127.0.0.1 \
+    --ssh-key "$workdir/id_ed25519" \
+    --ssh-known-hosts "$workdir/known_hosts" \
+    --iterations 5 \
+    --cold-native \
+    --assert-ssh-plus-ms "${DOSH_BENCH_NATIVE_SSH_PLUS_MS:-0}"; then
+  docker logs "$container_id" || true
+  docker exec "$container_id" sh -lc 'cat /tmp/dosh-server.log 2>/dev/null || true' || true
+  exit 1
+fi
+
 if ! HOME="$workdir/home-cached" target/release/dosh-bench \
     --server bench@127.0.0.1 \
     --ssh-port "$ssh_port" \

scripts/fuzz-run.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env sh
+set -eu
+
+seconds="${DOSH_FUZZ_SECONDS:-${1:-20}}"
+targets="
+packet_decode
+from_body
+authorized_keys
+known_hosts
+handshake_structs
+attach_ticket
+"
+
+if ! command -v cargo >/dev/null 2>&1; then
+  [ -f "$HOME/.cargo/env" ] && . "$HOME/.cargo/env"
+fi
+
+for target in $targets; do
+  echo "== fuzzing $target for ${seconds}s =="
+  cargo +nightly fuzz run --fuzz-dir fuzz "$target" -- \
+    -max_total_time="$seconds" -rss_limit_mb="${DOSH_FUZZ_RSS_MB:-4096}"
+done

scripts/package-release.sh

@@ -0,0 +1,85 @@
+#!/usr/bin/env sh
+set -eu
+
+repo_root="$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)"
+cd "$repo_root"
+
+out_dir="${DOSH_PACKAGE_DIR:-target/dosh-release}"
+version="${DOSH_VERSION:-$(sed -n 's/^version = "\(.*\)"/\1/p' Cargo.toml | sed -n '1p')}"
+
+normalize_os() {
+  case "$(uname -s)" in
+    Darwin) printf '%s\n' macos ;;
+    Linux) printf '%s\n' linux ;;
+    FreeBSD) printf '%s\n' freebsd ;;
+    MINGW*|MSYS*|CYGWIN*) printf '%s\n' windows ;;
+    *) uname -s | tr '[:upper:]' '[:lower:]' ;;
+  esac
+}
+
+normalize_arch() {
+  case "$(uname -m)" in
+    x86_64|amd64) printf '%s\n' x86_64 ;;
+    arm64|aarch64) printf '%s\n' aarch64 ;;
+    armv7l) printf '%s\n' armv7 ;;
+    *) uname -m | tr '[:upper:]' '[:lower:]' ;;
+  esac
+}
+
+os="$(normalize_os)"
+arch="$(normalize_arch)"
+if [ "$os" = "windows" ]; then
+  artifact="dosh-$os-$arch.zip"
+  versioned_artifact="dosh-$version-$os-$arch.zip"
+else
+  artifact="dosh-$os-$arch.tar.gz"
+  versioned_artifact="dosh-$version-$os-$arch.tar.gz"
+fi
+stage="$out_dir/stage/dosh"
+
+cargo build --release
+
+rm -rf "$stage"
+mkdir -p "$stage/bin" "$out_dir"
+for bin in dosh-client dosh-server dosh-auth dosh-bench; do
+  if [ -f "target/release/$bin" ]; then
+    install -m 0755 "target/release/$bin" "$stage/bin/$bin"
+  fi
+done
+printf '%s\n' "$version" >"$stage/VERSION"
+
+if [ "$os" = "windows" ]; then
+  if command -v powershell.exe >/dev/null 2>&1; then
+    powershell.exe -NoProfile -Command "Compress-Archive -Force -Path '$stage' -DestinationPath '$out_dir/$artifact'"
+  elif command -v zip >/dev/null 2>&1; then
+    (cd "$out_dir/stage" && zip -qr "../$artifact" dosh)
+  else
+    echo "windows packaging requires powershell.exe or zip" >&2
+    exit 1
+  fi
+else
+  tar -C "$out_dir/stage" -czf "$out_dir/$artifact" dosh
+fi
+cp "$out_dir/$artifact" "$out_dir/$versioned_artifact"
+
+write_sha256() {
+  file="$1"
+  if command -v sha256sum >/dev/null 2>&1; then
+    sha256sum "$file" >"$file.sha256"
+  elif command -v shasum >/dev/null 2>&1; then
+    shasum -a 256 "$file" >"$file.sha256"
+  else
+    echo "warning: sha256sum/shasum not found; skipping checksum for $file" >&2
+  fi
+}
+
+write_sha256 "$out_dir/$artifact"
+write_sha256 "$out_dir/$versioned_artifact"
+
+cat <<EOF
+Wrote:
+  $out_dir/$artifact
+  $out_dir/$artifact.sha256
+  $out_dir/$versioned_artifact
+  $out_dir/$versioned_artifact.sha256
+EOF

scripts/upload-gitea-release.sh

@@ -0,0 +1,98 @@
+#!/usr/bin/env sh
+set -eu
+
+usage() {
+  cat <<'EOF'
+Usage:
+  GITEA_TOKEN=... scripts/upload-gitea-release.sh TAG [artifact...]
+
+Environment:
+  GITEA_URL       Base URL, default https://git.palav.dev
+  GITEA_REPO      owner/repo, default Palav/dosh
+  GITEA_TOKEN     Token with release write permission
+  GITEA_TITLE     Release title, default TAG
+EOF
+}
+
+if [ "${1:-}" = "-h" ] || [ "${1:-}" = "--help" ]; then
+  usage
+  exit 0
+fi
+
+tag="${1:-}"
+if [ -z "$tag" ]; then
+  usage >&2
+  exit 2
+fi
+shift
+
+base="${GITEA_URL:-https://git.palav.dev}"
+repo="${GITEA_REPO:-Palav/dosh}"
+token="${GITEA_TOKEN:-}"
+title="${GITEA_TITLE:-$tag}"
+
+if [ -z "$token" ]; then
+  echo "GITEA_TOKEN is required" >&2
+  exit 2
+fi
+
+if [ "$#" -eq 0 ]; then
+  set -- target/dosh-release/dosh-*
+fi
+
+api="$base/api/v1/repos/$repo"
+auth_header="Authorization: token $token"
+
+release_json="$(curl -fsS -H "$auth_header" "$api/releases/tags/$tag" || true)"
+release_id=""
+if [ -n "$release_json" ] && command -v jq >/dev/null 2>&1; then
+  release_id="$(printf '%s\n' "$release_json" | jq -r '.id // empty')"
+elif [ -n "$release_json" ]; then
+  release_id="$(printf '%s\n' "$release_json" | sed -n 's/^[[:space:]]*{"id":[[:space:]]*\([0-9][0-9]*\).*/\1/p' | sed -n '1p')"
+fi
+
+if [ -z "$release_id" ]; then
+  payload="$(printf '{"tag_name":"%s","target_commitish":"main","name":"%s","body":"Dosh release %s","draft":false,"prerelease":false}\n' "$tag" "$title" "$tag")"
+  release_json="$(curl -fsS -H "$auth_header" -H 'Content-Type: application/json' -X POST "$api/releases" -d "$payload")"
+  if command -v jq >/dev/null 2>&1; then
+    release_id="$(printf '%s\n' "$release_json" | jq -r '.id // empty')"
+  else
+    release_id="$(printf '%s\n' "$release_json" | sed -n 's/^[[:space:]]*{"id":[[:space:]]*\([0-9][0-9]*\).*/\1/p' | sed -n '1p')"
+  fi
+fi
+
+if [ -z "$release_id" ]; then
+  echo "could not determine Gitea release id for $tag" >&2
+  exit 1
+fi
+
+delete_existing_asset() {
+  name="$1"
+  if ! command -v jq >/dev/null 2>&1; then
+    return 0
+  fi
+  printf '%s\n' "$release_json" \
+    | jq -r --arg name "$name" '.assets[]? | select(.name == $name) | .id' \
+    | while IFS= read -r asset_id; do
+      [ -n "$asset_id" ] || continue
+      echo "replacing $name"
+      curl -fsS \
+        -H "$auth_header" \
+        -X DELETE \
+        "$api/releases/$release_id/assets/$asset_id" >/dev/null
+    done
+}
+
+for artifact in "$@"; do
+  if [ ! -f "$artifact" ]; then
+    continue
+  fi
+  name="$(basename "$artifact")"
+  delete_existing_asset "$name"
+  echo "uploading $name"
+  curl -fsS \
+    -H "$auth_header" \
+    -X POST \
+    -F "attachment=@$artifact" \
+    "$api/releases/$release_id/assets?name=$name" >/dev/null
+done

src/bin/dosh-bench.rs

@@ -2,6 +2,8 @@ use anyhow::{Context, Result, anyhow};
 use clap::Parser;
 use portable_pty::{CommandBuilder, NativePtySystem, PtySize, PtySystem};
 use std::ffi::OsStr;
+use std::fmt::Write as _;
+use std::fs;
 use std::io::Read;
 use std::path::PathBuf;
 use std::process::Command;
@@ -63,6 +65,12 @@ struct Args {
     /// Emit machine-readable JSON (one object per metric, with raw samples).
     #[arg(long)]
     json: bool,
+    /// Emit a publishable Markdown benchmark report.
+    #[arg(long)]
+    markdown: bool,
+    /// Write the report to a file instead of stdout.
+    #[arg(long)]
+    output: Option<PathBuf>,
     /// Optional label printed in summary/JSON output (e.g. machine/OS identifier).
     #[arg(long)]
     label: Option<String>,
@@ -179,11 +187,14 @@ fn main() -> Result<()> {
         results.push(MetricSamples::new("mosh_start_true_ms", mosh_times));
     }
 
-    if args.json {
+    let report = if args.json {
-        print_json(&args, &results);
+        render_json(&args, &results)
+    } else if args.markdown {
+        render_markdown(&args, &results)
     } else {
-        print_table(&args, &results);
+        render_table(&args, &results)
-    }
+    };
+    write_report(&args, &report)?;
 
     run_assertions(&args, &results)?;
     Ok(())
@@ -560,17 +571,20 @@ fn percentile(sorted: &[f64], pct: f64) -> f64 {
     }
 }
 
-fn print_table(args: &Args, results: &[MetricSamples]) {
+fn render_table(args: &Args, results: &[MetricSamples]) -> String {
+    let mut out = String::new();
     if let Some(label) = &args.label {
-        println!("# label: {label}");
+        let _ = writeln!(out, "# label: {label}");
     }
-    println!(
+    let _ = writeln!(
+        out,
         "{:<24} {:>6} {:>9} {:>9} {:>9} {:>9} {:>9}",
         "metric", "n", "min", "median", "p95", "mean", "max"
     );
     for metric in results {
         let s = metric.stats();
-        println!(
+        let _ = writeln!(
+            out,
             "{:<24} {:>6} {:>9.2} {:>9.2} {:>9.2} {:>9.2} {:>9.2}",
             metric.name, s.count, s.min, s.median, s.p95, s.mean, s.max
         );
@@ -578,11 +592,12 @@ fn print_table(args: &Args, results: &[MetricSamples]) {
     // Raw per-iteration samples, so published numbers can include raw data.
     for metric in results {
         let ms: Vec<String> = metric.ms().iter().map(|v| format!("{v:.2}")).collect();
-        println!("{} samples_ms=[{}]", metric.name, ms.join(", "));
+        let _ = writeln!(out, "{} samples_ms=[{}]", metric.name, ms.join(", "));
     }
+    out
 }
 
-fn print_json(args: &Args, results: &[MetricSamples]) {
+fn render_json(args: &Args, results: &[MetricSamples]) -> String {
     let mut entries = Vec::new();
     for metric in results {
         let s = metric.stats();
@@ -603,11 +618,58 @@ fn print_json(args: &Args, results: &[MetricSamples]) {
         Some(label) => format!("\"{}\"", label.replace('"', "\\\"")),
         None => "null".to_string(),
     };
-    println!(
+    format!(
         "{{\"label\":{label},\"iterations\":{},\"metrics\":[{}]}}",
         args.iterations.max(1),
         entries.join(",")
+    )
+}
+
+fn render_markdown(args: &Args, results: &[MetricSamples]) -> String {
+    let mut out = String::new();
+    let label = args.label.as_deref().unwrap_or("Dosh benchmark");
+    let _ = writeln!(out, "# {label}\n");
+    let _ = writeln!(out, "- server: `{}`", args.server);
+    let _ = writeln!(out, "- iterations: `{}`", args.iterations.max(1));
+    let _ = writeln!(
+        out,
+        "- generated_by: `dosh-bench {}`\n",
+        env!("CARGO_PKG_VERSION")
     );
+    let _ = writeln!(
+        out,
+        "| metric | n | min ms | median ms | p95 ms | mean ms | max ms |"
+    );
+    let _ = writeln!(out, "|---|---:|---:|---:|---:|---:|---:|");
+    for metric in results {
+        let s = metric.stats();
+        let _ = writeln!(
+            out,
+            "| `{}` | {} | {:.2} | {:.2} | {:.2} | {:.2} | {:.2} |",
+            metric.name, s.count, s.min, s.median, s.p95, s.mean, s.max
+        );
+    }
+    let _ = writeln!(out, "\n## Raw Samples\n");
+    for metric in results {
+        let ms: Vec<String> = metric.ms().iter().map(|v| format!("{v:.2}")).collect();
+        let _ = writeln!(out, "- `{}`: [{}]", metric.name, ms.join(", "));
+    }
+    out
+}
+
+fn write_report(args: &Args, report: &str) -> Result<()> {
+    if let Some(path) = &args.output {
+        if let Some(parent) = path.parent()
+            && !parent.as_os_str().is_empty()
+        {
+            fs::create_dir_all(parent).with_context(|| format!("create {}", parent.display()))?;
+        }
+        fs::write(path, report).with_context(|| format!("write {}", path.display()))?;
+        println!("wrote {}", path.display());
+    } else {
+        println!("{report}");
+    }
+    Ok(())
 }
 
 fn metric_mean(results: &[MetricSamples], name: &str) -> Option<f64> {
@@ -677,3 +739,69 @@ fn default_client_path() -> PathBuf {
         .and_then(|path| path.parent().map(|parent| parent.join("dosh-client")))
         .unwrap_or_else(|| PathBuf::from("dosh-client"))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn args_for_render() -> Args {
+        Args {
+            server: "local".to_string(),
+            session: "default".to_string(),
+            ssh_port: 22,
+            dosh_port: 50000,
+            dosh_host: None,
+            iterations: 2,
+            local_auth: true,
+            cold_native: false,
+            cached_ticket: false,
+            resume: false,
+            client: None,
+            ssh_auth_command: "~/.local/bin/dosh-auth".to_string(),
+            ssh_key: None,
+            ssh_known_hosts: None,
+            ssh_control_path: None,
+            controlmaster: false,
+            no_cache: false,
+            warm_cache: false,
+            skip_ssh_baseline: true,
+            include_mosh: false,
+            mosh: PathBuf::from("mosh"),
+            mosh_server_command: "mosh-server".to_string(),
+            mosh_port: None,
+            json: false,
+            markdown: true,
+            output: None,
+            label: Some("test host".to_string()),
+            assert_ssh_plus_ms: None,
+            assert_mosh_minus_ms: None,
+            assert_dosh_max_ms: None,
+        }
+    }
+
+    #[test]
+    fn markdown_report_contains_summary_and_samples() {
+        let args = args_for_render();
+        let metrics = vec![MetricSamples::new(
+            "dosh_cached_attach_ms",
+            vec![Duration::from_millis(3), Duration::from_millis(5)],
+        )];
+        let report = render_markdown(&args, &metrics);
+        assert!(report.contains("# test host"));
+        assert!(report.contains("| `dosh_cached_attach_ms` | 2 | 3.00"));
+        assert!(report.contains("- `dosh_cached_attach_ms`: [3.00, 5.00]"));
+    }
+
+    #[test]
+    fn json_report_contains_metrics() {
+        let args = args_for_render();
+        let metrics = vec![MetricSamples::new(
+            "dosh_local_attach_ms",
+            vec![Duration::from_millis(7)],
+        )];
+        let report = render_json(&args, &metrics);
+        assert!(report.contains("\"label\":\"test host\""));
+        assert!(report.contains("\"metric\":\"dosh_local_attach_ms\""));
+        assert!(report.contains("\"samples_ms\":[7.0000]"));
+    }
+}

src/config.rs

@@ -46,6 +46,17 @@ pub struct ServerConfig {
     pub allow_agent_forwarding: bool,
     #[serde(default = "default_accept_env")]
     pub accept_env: Vec<String>,
+    /// Run each terminal session's shell under a small per-session *holder*
+    /// process so it survives a `dosh-server` restart (crash/upgrade/
+    /// `systemctl restart`). On startup the server re-adopts live holders and
+    /// reattaching clients land on the same shell with screen state intact. When
+    /// `false`, sessions behave exactly as before: the shell is a child of the
+    /// server and dies with it.
+    // Opt-in for now: this changes the core session model (per-session holder
+    // processes + fd passing), so it stays OFF by default until it has been
+    // stress-tested on a real host. Set `persist_sessions = true` to enable.
+    #[serde(default)]
+    pub persist_sessions: bool,
 }
 
 impl Default for ServerConfig {
@@ -76,6 +87,7 @@ impl Default for ServerConfig {
             allow_remote_non_loopback_bind: false,
             allow_agent_forwarding: false,
             accept_env: default_accept_env(),
+            persist_sessions: false,
         }
     }
 }
@@ -92,7 +104,7 @@ pub struct ClientConfig {
     pub default_session: String,
     pub reconnect_timeout_secs: u64,
     pub view_only: bool,
-    #[serde(default)]
+    #[serde(default = "default_true")]
     pub predict: bool,
     /// Prediction display policy: "off", "experimental" (adaptive, the default),
     /// or "always". Controls when speculative local echo is shown.
@@ -124,6 +136,11 @@ pub struct ClientConfig {
     pub send_env: Vec<String>,
     #[serde(default)]
     pub set_env: HashMap<String, String>,
+    /// Optional client-side command extensions. These are just shell command
+    /// templates expanded into the remote session's startup input; Dosh does not
+    /// depend on the tools they name.
+    #[serde(default)]
+    pub extensions: HashMap<String, CommandExtension>,
 }
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
@@ -139,6 +156,22 @@ pub struct HostConfig {
     pub send_env: Option<Vec<String>>,
     #[serde(default)]
     pub set_env: HashMap<String, String>,
+    /// Per-host extension overrides. A host can replace a global extension or set
+    /// `disabled = true` to opt out of it.
+    #[serde(default)]
+    pub extensions: HashMap<String, CommandExtension>,
+}
+
+#[derive(Debug, Clone, Default, Serialize, Deserialize, PartialEq, Eq)]
+pub struct CommandExtension {
+    /// Remote shell command template. `{args}` expands to shell-quoted extra
+    /// words after the extension name. When absent, extra args are appended.
+    #[serde(default)]
+    pub command: Option<String>,
+    #[serde(default)]
+    pub description: Option<String>,
+    #[serde(default)]
+    pub disabled: bool,
 }
 
 #[derive(Debug, Clone, Default, Serialize, Deserialize)]
@@ -160,7 +193,7 @@ impl Default for ClientConfig {
             default_session: "new".to_string(),
             reconnect_timeout_secs: 5,
             view_only: false,
-            predict: false,
+            predict: true,
             predict_mode: default_predict_mode(),
             cache_attach_tickets: true,
             credential_cache: "~/.local/share/dosh/credentials".to_string(),
@@ -174,6 +207,7 @@ impl Default for ClientConfig {
             disconnect_status: true,
             send_env: default_send_env(),
             set_env: HashMap::new(),
+            extensions: HashMap::new(),
         }
     }
 }

src/lib.rs

@@ -2,6 +2,7 @@ pub mod auth;
 pub mod config;
 pub mod crypto;
 pub mod native;
+pub mod persist;
 pub mod protocol;
 pub mod pty;
 pub mod ssh_agent;

src/native.rs

@@ -5,7 +5,9 @@ use anyhow::{Context, Result, bail};
 use base64::Engine;
 use base64::engine::general_purpose::{STANDARD, URL_SAFE_NO_PAD};
 use ed25519_dalek::{Signature, Signer, SigningKey, Verifier, VerifyingKey};
+use rsa::traits::PublicKeyParts;
 use serde::{Deserialize, Serialize};
+use signature::{SignatureEncoding, Signer as SignatureSigner, Verifier as SignatureVerifier};
 use std::fs;
 use std::io::Write;
 use std::net::IpAddr;
@@ -339,6 +341,92 @@ pub fn sign_user_auth(
     Ok(auth)
 }
 
+pub fn sign_user_auth_with_private_key(
+    private_key: &ssh_key::PrivateKey,
+    client: &NativeClientHello,
+    server: &NativeServerHello,
+    requested_forwardings: Vec<ForwardingRequest>,
+) -> Result<NativeUserAuth> {
+    anyhow::ensure!(!private_key.is_encrypted(), "OpenSSH identity is encrypted");
+    let public_key = private_key.public_key();
+    let key_algorithm = public_key.algorithm().as_str().to_string();
+    anyhow::ensure!(
+        is_supported_user_key_algorithm(&key_algorithm),
+        "unsupported native identity key algorithm {key_algorithm}"
+    );
+    let public_key_blob = ssh_public_blob_from_public_key(public_key)?;
+    let public_key_for_auth = if key_algorithm == "ssh-ed25519" {
+        parse_ssh_ed25519_public_blob(&public_key_blob)?.to_vec()
+    } else {
+        public_key_blob
+    };
+    let signature_algorithm = signature_algorithm_for_private_key(&key_algorithm)?;
+    let mut auth = NativeUserAuth {
+        public_key_algorithm: signature_algorithm.to_string(),
+        public_key: public_key_for_auth,
+        signature: Vec::new(),
+        requested_forwardings,
+    };
+    let transcript = user_auth_transcript(client, server, &auth)?;
+    auth.signature = if key_algorithm == "ssh-rsa" {
+        sign_rsa_sha512_private_key(private_key, &transcript)?
+    } else {
+        let signature = SignatureSigner::try_sign(private_key, &transcript)
+            .context("sign native user auth with OpenSSH private key")?;
+        anyhow::ensure!(
+            signature.algorithm().as_str() == auth.public_key_algorithm,
+            "private key produced signature algorithm {}, expected {}",
+            signature.algorithm().as_str(),
+            auth.public_key_algorithm
+        );
+        signature.as_bytes().to_vec()
+    };
+    Ok(auth)
+}
+
+fn sign_rsa_sha512_private_key(
+    private_key: &ssh_key::PrivateKey,
+    transcript: &[u8],
+) -> Result<Vec<u8>> {
+    let rsa_keypair = private_key
+        .key_data()
+        .rsa()
+        .ok_or_else(|| anyhow::anyhow!("OpenSSH identity is not ssh-rsa"))?;
+    let rsa_private = rsa_private_key_from_ssh_keypair(rsa_keypair)?;
+    let signing_key = rsa::pkcs1v15::SigningKey::<sha2::Sha512>::new(rsa_private);
+    let signature: rsa::pkcs1v15::Signature = SignatureSigner::sign(&signing_key, transcript);
+    Ok(signature.to_vec())
+}
+
+fn rsa_private_key_from_ssh_keypair(
+    keypair: &ssh_key::private::RsaKeypair,
+) -> Result<rsa::RsaPrivateKey> {
+    let private = rsa::RsaPrivateKey::from_components(
+        rsa::BigUint::try_from(&keypair.public.n).context("convert RSA modulus")?,
+        rsa::BigUint::try_from(&keypair.public.e).context("convert RSA public exponent")?,
+        rsa::BigUint::try_from(&keypair.private.d).context("convert RSA private exponent")?,
+        vec![
+            rsa::BigUint::try_from(&keypair.private.p).context("convert RSA p prime")?,
+            rsa::BigUint::try_from(&keypair.private.q).context("convert RSA q prime")?,
+        ],
+    )
+    .context("convert OpenSSH RSA private key")?;
+    anyhow::ensure!(
+        private.size().saturating_mul(8) >= 2048,
+        "OpenSSH RSA identity is smaller than 2048 bits"
+    );
+    Ok(private)
+}
+
+fn signature_algorithm_for_private_key(key_algorithm: &str) -> Result<&'static str> {
+    match key_algorithm {
+        "ssh-ed25519" => Ok("ssh-ed25519"),
+        "ecdsa-sha2-nistp256" => Ok("ecdsa-sha2-nistp256"),
+        "ssh-rsa" => Ok("rsa-sha2-512"),
+        _ => bail!("unsupported native identity key algorithm {key_algorithm}"),
+    }
+}
+
 pub fn verify_native_user_auth(
     client: &NativeClientHello,
     server: &NativeServerHello,
@@ -347,37 +435,127 @@ pub fn verify_native_user_auth(
     source_ip: Option<IpAddr>,
 ) -> Result<AuthorizedKey> {
     anyhow::ensure!(
-        auth.public_key_algorithm == "ssh-ed25519",
+        is_supported_user_signature_algorithm(&auth.public_key_algorithm),
         "unsupported native user key algorithm {}",
         auth.public_key_algorithm
     );
-    anyhow::ensure!(
+    let authorized_algorithm = authorized_key_algorithm_for_auth(&auth.public_key_algorithm)?;
-        auth.public_key.len() == 32,
-        "ssh-ed25519 public key must be 32 bytes"
-    );
-    anyhow::ensure!(
-        auth.signature.len() == 64,
-        "ssh-ed25519 signature must be 64 bytes"
-    );
     let authorized = authorized_keys
         .iter()
-        .find(|key| key.algorithm == "ssh-ed25519" && key.key == auth.public_key)
+        .find(|key| key.algorithm == authorized_algorithm && key.key == auth.public_key)
         .ok_or_else(|| anyhow::anyhow!("native user key is not authorized"))?;
     authorized.ensure_native_allowed(auth, source_ip)?;
 
-    let mut public_key = [0u8; 32];
-    public_key.copy_from_slice(&auth.public_key);
-    let verifying_key = VerifyingKey::from_bytes(&public_key).context("parse user public key")?;
-    let mut signature = [0u8; 64];
-    signature.copy_from_slice(&auth.signature);
-    let signature = Signature::from_bytes(&signature);
     let transcript = user_auth_transcript(client, server, auth)?;
-    verifying_key
+    verify_native_user_signature(auth, &transcript)?;
-        .verify(&transcript, &signature)
-        .context("verify native user signature")?;
     Ok(authorized.clone())
 }
 
+pub fn supported_user_key_algorithms() -> Vec<String> {
+    vec![
+        "ssh-ed25519".to_string(),
+        "ecdsa-sha2-nistp256".to_string(),
+        "rsa-sha2-512".to_string(),
+        "rsa-sha2-256".to_string(),
+    ]
+}
+
+pub fn is_supported_user_key_algorithm(algorithm: &str) -> bool {
+    matches!(algorithm, "ssh-ed25519" | "ecdsa-sha2-nistp256" | "ssh-rsa")
+}
+
+pub fn is_supported_user_signature_algorithm(algorithm: &str) -> bool {
+    matches!(
+        algorithm,
+        "ssh-ed25519" | "ecdsa-sha2-nistp256" | "rsa-sha2-512" | "rsa-sha2-256"
+    )
+}
+
+fn authorized_key_algorithm_for_auth(signature_algorithm: &str) -> Result<&'static str> {
+    match signature_algorithm {
+        "ssh-ed25519" => Ok("ssh-ed25519"),
+        "ecdsa-sha2-nistp256" => Ok("ecdsa-sha2-nistp256"),
+        "rsa-sha2-512" | "rsa-sha2-256" => Ok("ssh-rsa"),
+        _ => bail!("unsupported native user key algorithm {signature_algorithm}"),
+    }
+}
+
+fn verify_native_user_signature(auth: &NativeUserAuth, transcript: &[u8]) -> Result<()> {
+    match auth.public_key_algorithm.as_str() {
+        "ssh-ed25519" => {
+            anyhow::ensure!(
+                auth.public_key.len() == 32,
+                "ssh-ed25519 public key must be 32 bytes"
+            );
+            anyhow::ensure!(
+                auth.signature.len() == 64,
+                "ssh-ed25519 signature must be 64 bytes"
+            );
+            let mut public_key = [0u8; 32];
+            public_key.copy_from_slice(&auth.public_key);
+            let verifying_key =
+                VerifyingKey::from_bytes(&public_key).context("parse user public key")?;
+            let mut signature = [0u8; 64];
+            signature.copy_from_slice(&auth.signature);
+            let signature = Signature::from_bytes(&signature);
+            verifying_key
+                .verify(transcript, &signature)
+                .context("verify native user signature")?;
+        }
+        "ecdsa-sha2-nistp256" => {
+            let public_key = ssh_public_key_from_blob(&auth.public_key)
+                .context("parse native user SSH public key")?;
+            let algorithm =
+                ssh_key::Algorithm::from_str(&auth.public_key_algorithm).with_context(|| {
+                    format!("parse signature algorithm {}", auth.public_key_algorithm)
+                })?;
+            let signature = ssh_key::Signature::new(algorithm, auth.signature.clone())
+                .context("parse native user SSH signature")?;
+            SignatureVerifier::verify(public_key.key_data(), transcript, &signature)
+                .context("verify native user SSH signature")?;
+        }
+        "rsa-sha2-512" | "rsa-sha2-256" => {
+            verify_rsa_sha2_signature(
+                &auth.public_key,
+                &auth.public_key_algorithm,
+                transcript,
+                &auth.signature,
+            )?;
+        }
+        algorithm => bail!("unsupported native user key algorithm {algorithm}"),
+    }
+    Ok(())
+}
+
+fn verify_rsa_sha2_signature(
+    public_key_blob: &[u8],
+    signature_algorithm: &str,
+    transcript: &[u8],
+    signature: &[u8],
+) -> Result<()> {
+    let (e, n) = parse_ssh_rsa_public_blob(public_key_blob)?;
+    let public = rsa::RsaPublicKey::new(
+        rsa::BigUint::from_bytes_be(n),
+        rsa::BigUint::from_bytes_be(e),
+    )
+    .context("parse RSA public key")?;
+    let signature =
+        rsa::pkcs1v15::Signature::try_from(signature).context("parse RSA PKCS#1v1.5 signature")?;
+    match signature_algorithm {
+        "rsa-sha2-256" => {
+            let key = rsa::pkcs1v15::VerifyingKey::<sha2::Sha256>::new(public);
+            SignatureVerifier::verify(&key, transcript, &signature)
+                .context("verify RSA-SHA256 signature")
+        }
+        "rsa-sha2-512" => {
+            let key = rsa::pkcs1v15::VerifyingKey::<sha2::Sha512>::new(public);
+            SignatureVerifier::verify(&key, transcript, &signature)
+                .context("verify RSA-SHA512 signature")
+        }
+        _ => bail!("legacy ssh-rsa/SHA-1 signatures are not accepted"),
+    }
+}
+
 pub fn verify_native_user_auth_from_config(
     config: &ServerConfig,
     client: &NativeClientHello,
@@ -470,6 +648,35 @@ pub fn load_ed25519_identity_with_passphrase(
         .with_context(|| format!("parse ssh-ed25519 identity {}", path.display()))
 }
 
+pub fn load_native_identity(path: &Path) -> Result<ssh_key::PrivateKey> {
+    load_native_identity_with_passphrase(path, None)
+}
+
+pub fn load_native_identity_with_passphrase(
+    path: &Path,
+    passphrase: Option<&str>,
+) -> Result<ssh_key::PrivateKey> {
+    let raw = fs::read_to_string(path).with_context(|| format!("read {}", path.display()))?;
+    let private_key = ssh_key::PrivateKey::from_openssh(&raw)
+        .with_context(|| format!("parse OpenSSH identity {}", path.display()))?;
+    let private_key = if private_key.is_encrypted() {
+        let passphrase = passphrase
+            .ok_or_else(|| anyhow::anyhow!("OpenSSH identity {} is encrypted", path.display()))?;
+        private_key
+            .decrypt(passphrase)
+            .with_context(|| format!("decrypt OpenSSH identity {}", path.display()))?
+    } else {
+        private_key
+    };
+    let algorithm = private_key.public_key().algorithm().as_str().to_string();
+    anyhow::ensure!(
+        is_supported_user_key_algorithm(&algorithm),
+        "OpenSSH identity {} has unsupported native key algorithm {algorithm}",
+        path.display()
+    );
+    Ok(private_key)
+}
+
 impl AuthorizedKey {
     fn ensure_native_allowed(
         &self,
@@ -565,7 +772,7 @@ fn parse_authorized_key_line(line_number: usize, line: &str) -> Result<Authorize
         fields.len() >= 2,
         "authorized_keys:{line_number}: expected key fields"
     );
-    let (options, key_type_index) = if fields[0].starts_with("ssh-") {
+    let (options, key_type_index) = if is_supported_user_key_algorithm(&fields[0]) {
         (AuthorizedKeyOptions::default(), 0)
     } else {
         (parse_authorized_key_options(&fields[0])?, 1)
@@ -576,15 +783,20 @@ fn parse_authorized_key_line(line_number: usize, line: &str) -> Result<Authorize
     let key_blob = fields
         .get(key_type_index + 1)
         .with_context(|| format!("authorized_keys:{line_number}: missing key blob"))?;
-    anyhow::ensure!(
-        algorithm == "ssh-ed25519",
-        "authorized_keys:{line_number}: unsupported key type {algorithm}"
-    );
     let decoded = STANDARD
         .decode(key_blob)
         .with_context(|| format!("authorized_keys:{line_number}: decode key blob"))?;
-    let key = parse_ssh_ed25519_public_blob(&decoded)
+    anyhow::ensure!(
-        .with_context(|| format!("authorized_keys:{line_number}: parse ssh-ed25519 key"))?;
+        is_supported_user_key_algorithm(algorithm),
+        "authorized_keys:{line_number}: unsupported key type {algorithm}"
+    );
+    validate_supported_public_key_blob(algorithm, &decoded)
+        .with_context(|| format!("authorized_keys:{line_number}: parse {algorithm} key"))?;
+    let key = if algorithm == "ssh-ed25519" {
+        parse_ssh_ed25519_public_blob(&decoded)?.to_vec()
+    } else {
+        decoded
+    };
     let comment = if fields.len() > key_type_index + 2 {
         Some(fields[key_type_index + 2..].join(" "))
     } else {
@@ -598,6 +810,51 @@ fn parse_authorized_key_line(line_number: usize, line: &str) -> Result<Authorize
     })
 }
 
+fn validate_supported_public_key_blob(algorithm: &str, blob: &[u8]) -> Result<()> {
+    let blob_algorithm = ssh_public_key_blob_algorithm(blob)?;
+    anyhow::ensure!(
+        blob_algorithm == algorithm,
+        "key blob type {blob_algorithm} does not match authorized_keys type {algorithm}"
+    );
+    match algorithm {
+        "ssh-ed25519" => {
+            parse_ssh_ed25519_public_blob(blob)?;
+        }
+        "ecdsa-sha2-nistp256" | "ssh-rsa" => {
+            let _ = ssh_public_key_from_blob(blob)?;
+        }
+        _ => bail!("unsupported key type {algorithm}"),
+    }
+    Ok(())
+}
+
+fn ssh_public_key_blob_algorithm(blob: &[u8]) -> Result<String> {
+    let mut cursor = blob;
+    let algorithm = read_ssh_string(&mut cursor)?;
+    Ok(String::from_utf8_lossy(algorithm).to_string())
+}
+
+fn ssh_public_key_from_blob(blob: &[u8]) -> Result<ssh_key::PublicKey> {
+    let algorithm = ssh_public_key_blob_algorithm(blob)?;
+    let encoded = STANDARD.encode(blob);
+    ssh_key::PublicKey::from_openssh(&format!("{algorithm} {encoded}"))
+        .with_context(|| format!("parse OpenSSH public key blob {algorithm}"))
+}
+
+fn ssh_public_blob_from_public_key(public_key: &ssh_key::PublicKey) -> Result<Vec<u8>> {
+    let line = public_key
+        .to_openssh()
+        .context("encode OpenSSH public key")?;
+    let mut fields = line.split_whitespace();
+    let _algorithm = fields
+        .next()
+        .context("encoded public key missing algorithm")?;
+    let encoded = fields.next().context("encoded public key missing blob")?;
+    STANDARD
+        .decode(encoded)
+        .context("decode encoded OpenSSH public key blob")
+}
+
 fn split_authorized_key_fields(line: &str) -> Vec<String> {
     line.split_whitespace().map(ToString::to_string).collect()
 }
@@ -765,6 +1022,18 @@ pub fn parse_ssh_ed25519_public_blob(blob: &[u8]) -> Result<[u8; 32]> {
     Ok(out)
 }
 
+fn parse_ssh_rsa_public_blob(blob: &[u8]) -> Result<(&[u8], &[u8])> {
+    let mut cursor = blob;
+    let key_type = read_ssh_string(&mut cursor)?;
+    anyhow::ensure!(key_type == b"ssh-rsa", "key blob type mismatch");
+    let e = read_ssh_mpint(&mut cursor)?;
+    let n = read_ssh_mpint(&mut cursor)?;
+    anyhow::ensure!(cursor.is_empty(), "trailing data in ssh-rsa key blob");
+    anyhow::ensure!(!e.is_empty(), "ssh-rsa exponent is empty");
+    anyhow::ensure!(!n.is_empty(), "ssh-rsa modulus is empty");
+    Ok((e, n))
+}
+
 pub fn ssh_ed25519_public_blob(public_key: &[u8; 32]) -> Vec<u8> {
     let mut out = Vec::new();
     write_ssh_string(&mut out, b"ssh-ed25519");
@@ -772,6 +1041,12 @@ pub fn ssh_ed25519_public_blob(public_key: &[u8; 32]) -> Vec<u8> {
     out
 }
 
+fn read_ssh_mpint<'a>(cursor: &mut &'a [u8]) -> Result<&'a [u8]> {
+    let raw = read_ssh_string(cursor)?;
+    let raw = raw.strip_prefix(&[0]).unwrap_or(raw);
+    Ok(raw)
+}
+
 fn read_ssh_string<'a>(cursor: &mut &'a [u8]) -> Result<&'a [u8]> {
     anyhow::ensure!(cursor.len() >= 4, "truncated SSH string length");
     let len = u32::from_be_bytes(cursor[..4].try_into().unwrap()) as usize;
@@ -1004,16 +1279,16 @@ mod tests {
         let second = host_public_key(&SigningKey::from_bytes(&[2u8; 32]));
 
         assert_eq!(
-            trust_host(&path, "palav", &first, "ssh", false).unwrap(),
+            trust_host(&path, "homelab", &first, "ssh", false).unwrap(),
             TrustResult::Trusted
         );
         assert_eq!(
-            trust_host(&path, "palav", &first, "ssh", false).unwrap(),
+            trust_host(&path, "homelab", &first, "ssh", false).unwrap(),
             TrustResult::AlreadyTrusted
         );
-        assert!(trust_host(&path, "palav", &second, "ssh", false).is_err());
+        assert!(trust_host(&path, "homelab", &second, "ssh", false).is_err());
         assert_eq!(
-            trust_host(&path, "palav", &second, "ssh", true).unwrap(),
+            trust_host(&path, "homelab", &second, "ssh", true).unwrap(),
             TrustResult::Trusted
         );
     }
@@ -1026,16 +1301,16 @@ mod tests {
         let second = host_public_key(&SigningKey::from_bytes(&[2u8; 32]));
 
         assert_eq!(
-            verify_known_host(&path, "palav", &first).unwrap(),
+            verify_known_host(&path, "homelab", &first).unwrap(),
             KnownHostStatus::Unknown
         );
-        trust_host(&path, "palav", &first, "ssh", false).unwrap();
+        trust_host(&path, "homelab", &first, "ssh", false).unwrap();
         assert_eq!(
-            verify_known_host(&path, "palav", &first).unwrap(),
+            verify_known_host(&path, "homelab", &first).unwrap(),
             KnownHostStatus::Trusted
         );
         assert!(matches!(
-            verify_known_host(&path, "palav", &second).unwrap(),
+            verify_known_host(&path, "homelab", &second).unwrap(),
             KnownHostStatus::Mismatch { .. }
         ));
     }
@@ -1084,6 +1359,45 @@ mod tests {
         assert!(verify_native_user_auth(&client, &server, &auth, &removed, None).is_err());
     }
 
+    #[test]
+    fn native_user_auth_accepts_ecdsa_p256_private_key() {
+        let mut rng = rand::rngs::OsRng;
+        let private = ssh_key::PrivateKey::random(
+            &mut rng,
+            ssh_key::Algorithm::Ecdsa {
+                curve: ssh_key::EcdsaCurve::NistP256,
+            },
+        )
+        .unwrap();
+        let host_signing = SigningKey::from_bytes(&[10u8; 32]);
+        let client = test_client_hello();
+        let mut server = test_server_hello(&host_signing);
+        sign_server_hello(&host_signing, &client, &mut server).unwrap();
+        let auth = sign_user_auth_with_private_key(&private, &client, &server, Vec::new()).unwrap();
+        let authorized =
+            parse_authorized_keys(&private.public_key().to_openssh().unwrap()).unwrap();
+
+        assert_eq!(auth.public_key_algorithm, "ecdsa-sha2-nistp256");
+        verify_native_user_auth(&client, &server, &auth, &authorized, None).unwrap();
+    }
+
+    #[test]
+    fn native_user_auth_accepts_rsa_sha2_private_key() {
+        let mut rng = rand::rngs::OsRng;
+        let private =
+            ssh_key::PrivateKey::random(&mut rng, ssh_key::Algorithm::Rsa { hash: None }).unwrap();
+        let host_signing = SigningKey::from_bytes(&[11u8; 32]);
+        let client = test_client_hello();
+        let mut server = test_server_hello(&host_signing);
+        sign_server_hello(&host_signing, &client, &mut server).unwrap();
+        let auth = sign_user_auth_with_private_key(&private, &client, &server, Vec::new()).unwrap();
+        let authorized =
+            parse_authorized_keys(&private.public_key().to_openssh().unwrap()).unwrap();
+
+        assert_eq!(auth.public_key_algorithm, "rsa-sha2-512");
+        verify_native_user_auth(&client, &server, &auth, &authorized, None).unwrap();
+    }
+
     #[test]
     fn native_user_auth_rejects_tampered_transcript() {
         let host_signing = SigningKey::from_bytes(&[3u8; 32]);
@@ -1311,8 +1625,8 @@ mod tests {
             protocol_version: NATIVE_PROTOCOL_VERSION,
             client_random: [1u8; 32],
             client_ephemeral_public: [2u8; 32],
-            requested_host: "palav".to_string(),
+            requested_host: "homelab".to_string(),
-            requested_user: "palav".to_string(),
+            requested_user: "alice".to_string(),
             requested_session: "term".to_string(),
             requested_mode: "read-write".to_string(),
             terminal_size: (80, 24),

src/persist.rs

@@ -0,0 +1,658 @@
+//! Session persistence across server restarts.
+//!
+//! A persistent dosh session's shell does not run as a child of `dosh-server`.
+//! Instead the server spawns a tiny per-session *holder* process (the same
+//! `dosh-server` binary re-exec'd as `dosh-server hold ...`). The holder calls
+//! `setsid()` to leave the server's process group/session, opens a PTY, spawns
+//! the shell as ITS own child, and listens on a Unix socket in a per-session
+//! runtime directory. The server connects to that socket and the holder hands it
+//! the PTY master fd over `SCM_RIGHTS`.
+//!
+//! Because the shell belongs to the holder (which is in its own session and is
+//! not waited on by the server), killing or restarting `dosh-server` leaves the
+//! holder + shell alive. On startup the server scans the runtime directory,
+//! reconnects to each live holder, receives the master fd again, and rebuilds the
+//! in-memory session so clients reattach to the very same shell.
+//!
+//! Screen / scrollback state lives only in server memory, so it is also mirrored
+//! to disk (atomically) and restored on re-adoption, letting a reattaching client
+//! repaint the screen exactly as it was before the restart.
+
+use anyhow::{Context, Result, anyhow, bail};
+use std::io::{Read, Write};
+use std::os::fd::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
+use std::os::unix::net::{UnixListener, UnixStream};
+use std::path::{Path, PathBuf};
+use std::time::Duration;
+
+/// One-byte commands a server sends to a holder over its control socket after
+/// the holder has handed back the master fd.
+const HOLDER_CMD_SHUTDOWN: u8 = b'X';
+
+/// Magic written into a holder's `meta` file, bumped if the on-disk layout
+/// changes so a stale holder from an incompatible build is ignored.
+const META_MAGIC: &str = "dosh-holder-1";
+
+/// Per-session runtime metadata persisted next to the holder socket.
+#[derive(Debug, Clone)]
+pub struct HolderMeta {
+    pub session: String,
+    pub shell_pid: i32,
+}
+
+/// Root runtime directory holding one subdirectory per persistent session.
+/// Lives under `sessions_dir/run` so it shares the session storage location and
+/// can be wiped with it.
+pub fn runtime_root(sessions_dir: &Path) -> PathBuf {
+    sessions_dir.join("run")
+}
+
+/// Map a session name to a filesystem-safe directory name. Session names are
+/// user-controlled, so hex-encode them rather than trusting them as path
+/// components (avoids traversal, slashes, NULs, length issues).
+fn session_dir_name(session: &str) -> String {
+    let mut out = String::with_capacity(session.len() * 2);
+    for byte in session.as_bytes() {
+        out.push(char::from_digit((byte >> 4) as u32, 16).unwrap());
+        out.push(char::from_digit((byte & 0xf) as u32, 16).unwrap());
+    }
+    out
+}
+
+fn decode_session_dir_name(name: &str) -> Option<String> {
+    if !name.len().is_multiple_of(2) {
+        return None;
+    }
+    let mut bytes = Vec::with_capacity(name.len() / 2);
+    let raw = name.as_bytes();
+    let mut i = 0;
+    while i < raw.len() {
+        let hi = (raw[i] as char).to_digit(16)?;
+        let lo = (raw[i + 1] as char).to_digit(16)?;
+        bytes.push(((hi << 4) | lo) as u8);
+        i += 2;
+    }
+    String::from_utf8(bytes).ok()
+}
+
+/// Directory for one session's holder runtime state.
+pub fn session_runtime_dir(sessions_dir: &Path, session: &str) -> PathBuf {
+    runtime_root(sessions_dir).join(session_dir_name(session))
+}
+
+fn holder_sock_path(dir: &Path) -> PathBuf {
+    dir.join("holder.sock")
+}
+
+fn meta_path(dir: &Path) -> PathBuf {
+    dir.join("meta")
+}
+
+fn screen_path(dir: &Path) -> PathBuf {
+    dir.join("screen")
+}
+
+/// Create the runtime directory tree with private (0700) permissions.
+pub fn ensure_runtime_dir(sessions_dir: &Path, session: &str) -> Result<PathBuf> {
+    use std::os::unix::fs::PermissionsExt;
+    let root = runtime_root(sessions_dir);
+    std::fs::create_dir_all(&root).with_context(|| format!("create {}", root.display()))?;
+    let _ = std::fs::set_permissions(&root, std::fs::Permissions::from_mode(0o700));
+    let dir = session_runtime_dir(sessions_dir, session);
+    std::fs::create_dir_all(&dir).with_context(|| format!("create {}", dir.display()))?;
+    std::fs::set_permissions(&dir, std::fs::Permissions::from_mode(0o700))
+        .with_context(|| format!("chmod {}", dir.display()))?;
+    Ok(dir)
+}
+
+/// Atomically write `data` to `path` (write temp + rename), so a concurrent
+/// reader (e.g. a restarting server) never sees a half-written file.
+fn atomic_write(path: &Path, data: &[u8]) -> Result<()> {
+    use std::os::unix::fs::PermissionsExt;
+    let tmp = path.with_extension("tmp");
+    {
+        let mut file =
+            std::fs::File::create(&tmp).with_context(|| format!("create {}", tmp.display()))?;
+        let _ = file.set_permissions(std::fs::Permissions::from_mode(0o600));
+        file.write_all(data)
+            .with_context(|| format!("write {}", tmp.display()))?;
+        file.sync_all().ok();
+    }
+    std::fs::rename(&tmp, path)
+        .with_context(|| format!("rename {} -> {}", tmp.display(), path.display()))?;
+    Ok(())
+}
+
+/// Persist the vt100 screen snapshot plus recent raw output for a session so a
+/// post-restart reattach repaints correctly. `snapshot` is the bytes a fresh
+/// attach would receive (alt-screen toggle + `state_formatted`).
+pub fn save_screen(
+    sessions_dir: &Path,
+    session: &str,
+    cols: u16,
+    rows: u16,
+    output_seq: u64,
+    snapshot: &[u8],
+) -> Result<()> {
+    let dir = session_runtime_dir(sessions_dir, session);
+    if !dir.exists() {
+        // No holder runtime for this session (non-persistent): nothing to do.
+        return Ok(());
+    }
+    let mut buf = Vec::with_capacity(snapshot.len() + 32);
+    buf.extend_from_slice(&cols.to_be_bytes());
+    buf.extend_from_slice(&rows.to_be_bytes());
+    buf.extend_from_slice(&output_seq.to_be_bytes());
+    buf.extend_from_slice(&(snapshot.len() as u32).to_be_bytes());
+    buf.extend_from_slice(snapshot);
+    atomic_write(&screen_path(&dir), &buf)
+}
+
+/// A restored screen for a re-adopted session.
+pub struct SavedScreen {
+    pub cols: u16,
+    pub rows: u16,
+    pub output_seq: u64,
+    pub snapshot: Vec<u8>,
+}
+
+/// Load a previously persisted screen, if any.
+pub fn load_screen(sessions_dir: &Path, session: &str) -> Option<SavedScreen> {
+    let dir = session_runtime_dir(sessions_dir, session);
+    let data = std::fs::read(screen_path(&dir)).ok()?;
+    if data.len() < 16 {
+        return None;
+    }
+    let cols = u16::from_be_bytes(data[0..2].try_into().ok()?);
+    let rows = u16::from_be_bytes(data[2..4].try_into().ok()?);
+    let output_seq = u64::from_be_bytes(data[4..12].try_into().ok()?);
+    let len = u32::from_be_bytes(data[12..16].try_into().ok()?) as usize;
+    if data.len() < 16 + len {
+        return None;
+    }
+    Some(SavedScreen {
+        cols,
+        rows,
+        output_seq,
+        snapshot: data[16..16 + len].to_vec(),
+    })
+}
+
+fn write_meta(dir: &Path, meta: &HolderMeta) -> Result<()> {
+    let body = format!("{META_MAGIC}\n{}\n{}\n", meta.shell_pid, meta.session);
+    atomic_write(&meta_path(dir), body.as_bytes())
+}
+
+fn read_meta(dir: &Path) -> Option<HolderMeta> {
+    let body = std::fs::read_to_string(meta_path(dir)).ok()?;
+    let mut lines = body.lines();
+    if lines.next()? != META_MAGIC {
+        return None;
+    }
+    let shell_pid: i32 = lines.next()?.parse().ok()?;
+    let session = lines.next()?.to_string();
+    Some(HolderMeta { session, shell_pid })
+}
+
+/// Spawn a holder process for `session`: re-exec this binary as `dosh-server
+/// hold` with the runtime dir, shell, terminal size, and accepted env. The
+/// holder daemonizes (setsid, owns the PTY) and listens on its control socket.
+/// Returns once the holder has signalled readiness by creating its socket.
+#[allow(clippy::too_many_arguments)]
+pub fn spawn_holder(
+    sessions_dir: &Path,
+    session: &str,
+    shell: &str,
+    cols: u16,
+    rows: u16,
+    env: &[(String, String)],
+) -> Result<()> {
+    let dir = ensure_runtime_dir(sessions_dir, session)?;
+    let sock = holder_sock_path(&dir);
+    // Clear any stale socket left by a crashed holder with the same name.
+    let _ = std::fs::remove_file(&sock);
+
+    let exe = std::env::current_exe().context("locate current executable")?;
+    let mut cmd = std::process::Command::new(exe);
+    cmd.arg("hold")
+        .arg("--runtime-dir")
+        .arg(&dir)
+        .arg("--session")
+        .arg(session)
+        .arg("--shell")
+        .arg(shell)
+        .arg("--cols")
+        .arg(cols.to_string())
+        .arg("--rows")
+        .arg(rows.to_string());
+    for (name, value) in env {
+        cmd.arg("--env").arg(format!("{name}={value}"));
+    }
+    cmd.stdin(std::process::Stdio::null())
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null());
+    let mut child = cmd.spawn().context("spawn holder process")?;
+
+    // Wait (briefly) for the holder to come up. The holder forks/setsids before
+    // creating the socket; once the socket exists we can connect. We also reap
+    // the short-lived launcher child so it never becomes a zombie.
+    let deadline = std::time::Instant::now() + Duration::from_secs(5);
+    loop {
+        if sock.exists() {
+            break;
+        }
+        if std::time::Instant::now() >= deadline {
+            let _ = child.kill();
+            let _ = child.wait();
+            bail!("holder for session {session} did not come up in time");
+        }
+        std::thread::sleep(Duration::from_millis(20));
+    }
+    // The launcher exits immediately after the grandchild setsids; reap it.
+    let _ = child.wait();
+    Ok(())
+}
+
+/// Connect to a session's holder and receive the PTY master fd over SCM_RIGHTS.
+/// Returns the raw fd (caller owns it) and the holder control socket, kept open
+/// so the server can later ask the holder to shut down. Returns an error if the
+/// holder is gone (caller then degrades to a fresh, non-persistent session).
+pub fn adopt_holder(sessions_dir: &Path, session: &str) -> Result<(RawFd, UnixStream)> {
+    let dir = session_runtime_dir(sessions_dir, session);
+    let sock = holder_sock_path(&dir);
+    let mut stream = UnixStream::connect(&sock)
+        .with_context(|| format!("connect holder socket {}", sock.display()))?;
+    stream.set_read_timeout(Some(Duration::from_secs(5))).ok();
+    let fd = recv_fd(&mut stream).context("receive master fd from holder")?;
+    Ok((fd, stream))
+}
+
+/// Ask a holder to terminate its shell and exit, then clean its runtime dir.
+/// Used when reaping a truly-abandoned persistent session.
+pub fn request_shutdown(sessions_dir: &Path, session: &str, control: Option<&mut UnixStream>) {
+    if let Some(stream) = control {
+        let _ = stream.write_all(&[HOLDER_CMD_SHUTDOWN]);
+        let _ = stream.flush();
+    } else {
+        let dir = session_runtime_dir(sessions_dir, session);
+        if let Ok(mut stream) = UnixStream::connect(holder_sock_path(&dir)) {
+            // Drain the fd the holder sends on connect, then send shutdown.
+            let _ = recv_fd(&mut stream);
+            let _ = stream.write_all(&[HOLDER_CMD_SHUTDOWN]);
+            let _ = stream.flush();
+        }
+    }
+    // Give the holder a moment to tear down, then remove its runtime dir.
+    std::thread::sleep(Duration::from_millis(50));
+    let dir = session_runtime_dir(sessions_dir, session);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// Remove a session's runtime directory unconditionally (best effort).
+pub fn remove_runtime_dir(sessions_dir: &Path, session: &str) {
+    let dir = session_runtime_dir(sessions_dir, session);
+    let _ = std::fs::remove_dir_all(&dir);
+}
+
+/// Scan the runtime root for holders left behind by a previous server. Returns
+/// `(session_name, meta)` for each one whose holder process still appears alive.
+/// Stale entries (no live process) are cleaned up.
+pub fn scan_existing_holders(sessions_dir: &Path) -> Vec<HolderMeta> {
+    let root = runtime_root(sessions_dir);
+    let mut found = Vec::new();
+    let Ok(entries) = std::fs::read_dir(&root) else {
+        return found;
+    };
+    for entry in entries.flatten() {
+        let dir = entry.path();
+        if !dir.is_dir() {
+            continue;
+        }
+        let Some(name) = dir.file_name().and_then(|n| n.to_str()) else {
+            continue;
+        };
+        // Decode the on-disk name back to a session name; skip junk dirs.
+        if decode_session_dir_name(name).is_none() {
+            continue;
+        }
+        match read_meta(&dir) {
+            Some(meta) if process_alive(meta.shell_pid) && holder_sock_path(&dir).exists() => {
+                found.push(meta);
+            }
+            _ => {
+                // Holder gone or meta unreadable: clean up so we don't try to
+                // adopt a dead session (degrade to fresh on next attach).
+                let _ = std::fs::remove_dir_all(&dir);
+            }
+        }
+    }
+    found
+}
+
+/// Whether a pid refers to a live process (signal 0 probe).
+fn process_alive(pid: i32) -> bool {
+    if pid <= 0 {
+        return false;
+    }
+    unsafe {
+        libc::kill(pid, 0) == 0
+            || std::io::Error::last_os_error().raw_os_error() == Some(libc::EPERM)
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Holder process entry point
+// ---------------------------------------------------------------------------
+
+/// Run as a holder process. Daemonizes (double-fork + setsid), opens a PTY,
+/// spawns the shell as its own child, and serves the control socket: every
+/// accepted connection is handed the master fd (SCM_RIGHTS); a subsequent
+/// SHUTDOWN byte (or the shell exiting) tears everything down.
+///
+/// This function does not return on success — it `exit`s the process. Errors
+/// before the daemonization point are returned to the launcher.
+#[allow(clippy::too_many_arguments)]
+pub fn run_holder(
+    runtime_dir: &Path,
+    session: &str,
+    shell: &str,
+    cols: u16,
+    rows: u16,
+    env: &[(String, String)],
+) -> Result<()> {
+    use portable_pty::{NativePtySystem, PtySize, PtySystem};
+
+    // Detach from the launching server: own session + process group so a server
+    // exit (even a process-group kill of the service) does not take us down.
+    daemonize().context("daemonize holder")?;
+
+    let pty_system = NativePtySystem::default();
+    let pair = pty_system
+        .openpty(PtySize {
+            rows,
+            cols,
+            pixel_width: 0,
+            pixel_height: 0,
+        })
+        .context("holder open pty")?;
+    let cmd = crate::pty::build_shell_command(shell, env);
+    let mut child = pair
+        .slave
+        .spawn_command(cmd)
+        .context("holder spawn shell")?;
+    drop(pair.slave);
+    let master_fd = pair
+        .master
+        .as_raw_fd()
+        .ok_or_else(|| anyhow!("holder master has no raw fd"))?;
+    let shell_pid = child.process_id().map(|p| p as i32).unwrap_or(-1);
+
+    write_meta(
+        runtime_dir,
+        &HolderMeta {
+            session: session.to_string(),
+            shell_pid,
+        },
+    )?;
+
+    let sock = holder_sock_path(runtime_dir);
+    let _ = std::fs::remove_file(&sock);
+    let listener =
+        UnixListener::bind(&sock).with_context(|| format!("holder bind {}", sock.display()))?;
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let _ = std::fs::set_permissions(&sock, std::fs::Permissions::from_mode(0o600));
+    }
+    listener
+        .set_nonblocking(false)
+        .context("holder listener blocking")?;
+
+    // A watcher thread reaps the shell: when it exits, the holder cleans up and
+    // exits too, so an abandoned shell does not linger forever.
+    let runtime_owned = runtime_dir.to_path_buf();
+    std::thread::spawn(move || {
+        let _ = child.wait();
+        // Shell exited: remove runtime dir and exit the holder process.
+        let _ = std::fs::remove_dir_all(&runtime_owned);
+        std::process::exit(0);
+    });
+
+    // Accept loop: each connecting server gets the master fd; a SHUTDOWN byte
+    // from any of them tears the holder down. Multiple servers never run at once
+    // in practice (one service), but serving repeated connections lets a server
+    // restart re-adopt cleanly.
+    for stream in listener.incoming() {
+        let Ok(mut stream) = stream else { continue };
+        if send_fd(&mut stream, master_fd).is_err() {
+            continue;
+        }
+        // Wait for an optional command byte. EOF (server dropped the control
+        // socket on its own exit) just means "keep running, await re-adoption".
+        let mut cmd = [0u8; 1];
+        match stream.read(&mut cmd) {
+            Ok(1) if cmd[0] == HOLDER_CMD_SHUTDOWN => {
+                let _ = std::fs::remove_dir_all(runtime_dir);
+                std::process::exit(0);
+            }
+            _ => {
+                // Server detached (exit/restart) or sent nothing actionable:
+                // loop back and wait for the next server to re-adopt us.
+            }
+        }
+    }
+    Ok(())
+}
+
+/// Double-fork + `setsid` so the holder runs in its own session, detached from
+/// the server's controlling terminal and process group. Without this a
+/// `systemctl restart` (which signals the whole service cgroup/process group)
+/// could take the holder down with the server.
+fn daemonize() -> Result<()> {
+    // First fork: parent (launcher) returns to reap; child continues.
+    match unsafe { libc::fork() } {
+        -1 => bail!("fork: {}", std::io::Error::last_os_error()),
+        0 => {}
+        _ => {
+            // Parent process: exit so the launcher's wait() returns promptly and
+            // the grandchild is reparented to init.
+            std::process::exit(0);
+        }
+    }
+    // New session: detaches from controlling tty and the server's process group.
+    if unsafe { libc::setsid() } == -1 {
+        bail!("setsid: {}", std::io::Error::last_os_error());
+    }
+    // Second fork: ensures we are not a session leader, so we can never
+    // re-acquire a controlling terminal.
+    match unsafe { libc::fork() } {
+        -1 => bail!("fork2: {}", std::io::Error::last_os_error()),
+        0 => Ok(()),
+        _ => std::process::exit(0),
+    }
+}
+
+// ---------------------------------------------------------------------------
+// SCM_RIGHTS file-descriptor passing over a Unix domain socket
+// ---------------------------------------------------------------------------
+
+/// Send a single fd over `stream` using SCM_RIGHTS, with one byte of normal data
+/// (sendmsg requires at least one iovec byte for the ancillary data to ride on).
+fn send_fd(stream: &mut UnixStream, fd: RawFd) -> Result<()> {
+    let dummy: [u8; 1] = [0];
+    let mut iov = libc::iovec {
+        iov_base: dummy.as_ptr() as *mut libc::c_void,
+        iov_len: 1,
+    };
+    let mut cmsg_buf = [0u8; cmsg_space_one_fd()];
+    let mut msg: libc::msghdr = unsafe { std::mem::zeroed() };
+    msg.msg_iov = &mut iov;
+    msg.msg_iovlen = 1;
+    msg.msg_control = cmsg_buf.as_mut_ptr() as *mut libc::c_void;
+    msg.msg_controllen = cmsg_buf.len() as _;
+
+    unsafe {
+        let cmsg = libc::CMSG_FIRSTHDR(&msg);
+        if cmsg.is_null() {
+            bail!("CMSG_FIRSTHDR null");
+        }
+        (*cmsg).cmsg_level = libc::SOL_SOCKET;
+        (*cmsg).cmsg_type = libc::SCM_RIGHTS;
+        (*cmsg).cmsg_len = libc::CMSG_LEN(std::mem::size_of::<RawFd>() as u32) as _;
+        std::ptr::copy_nonoverlapping(
+            &fd as *const RawFd as *const u8,
+            libc::CMSG_DATA(cmsg),
+            std::mem::size_of::<RawFd>(),
+        );
+        let n = libc::sendmsg(stream.as_raw_fd(), &msg, 0);
+        if n < 0 {
+            return Err(std::io::Error::last_os_error()).context("sendmsg SCM_RIGHTS");
+        }
+    }
+    Ok(())
+}
+
+/// Receive a single fd sent via SCM_RIGHTS. Returns a fresh fd owned by the
+/// caller.
+fn recv_fd(stream: &mut UnixStream) -> Result<RawFd> {
+    let mut dummy = [0u8; 1];
+    let mut iov = libc::iovec {
+        iov_base: dummy.as_mut_ptr() as *mut libc::c_void,
+        iov_len: 1,
+    };
+    let mut cmsg_buf = [0u8; cmsg_space_one_fd()];
+    let mut msg: libc::msghdr = unsafe { std::mem::zeroed() };
+    msg.msg_iov = &mut iov;
+    msg.msg_iovlen = 1;
+    msg.msg_control = cmsg_buf.as_mut_ptr() as *mut libc::c_void;
+    msg.msg_controllen = cmsg_buf.len() as _;
+
+    unsafe {
+        let n = libc::recvmsg(stream.as_raw_fd(), &mut msg, 0);
+        if n < 0 {
+            return Err(std::io::Error::last_os_error()).context("recvmsg SCM_RIGHTS");
+        }
+        if n == 0 {
+            bail!("holder closed connection before sending fd");
+        }
+        let cmsg = libc::CMSG_FIRSTHDR(&msg);
+        if cmsg.is_null() {
+            bail!("no ancillary data (fd) received from holder");
+        }
+        if (*cmsg).cmsg_level != libc::SOL_SOCKET || (*cmsg).cmsg_type != libc::SCM_RIGHTS {
+            bail!("unexpected ancillary message from holder");
+        }
+        let mut fd: RawFd = -1;
+        std::ptr::copy_nonoverlapping(
+            libc::CMSG_DATA(cmsg),
+            &mut fd as *mut RawFd as *mut u8,
+            std::mem::size_of::<RawFd>(),
+        );
+        if fd < 0 {
+            bail!("invalid fd received from holder");
+        }
+        Ok(fd)
+    }
+}
+
+/// Space, in bytes, needed for a control-message buffer carrying exactly one fd.
+const fn cmsg_space_one_fd() -> usize {
+    // CMSG_SPACE is not const in libc; this is the equivalent for one RawFd.
+    // cmsghdr is aligned to size_of::<usize>(); add data length rounded up.
+    let data = std::mem::size_of::<RawFd>();
+    let hdr = std::mem::size_of::<libc::cmsghdr>();
+    let align = std::mem::size_of::<usize>();
+    // round(hdr) + round(data)
+    ((hdr + align - 1) & !(align - 1)) + ((data + align - 1) & !(align - 1))
+}
+
+/// Helper used by `adopt_holder` callers to turn the received raw fd into an
+/// owned `File`-like object if they need RAII (the server hands it to
+/// `pty::adopt_pty_from_fd`, which takes ownership of the raw fd).
+pub fn fd_into_file(fd: RawFd) -> std::fs::File {
+    unsafe { std::fs::File::from_raw_fd(fd) }
+}
+
+/// Convert a `File` back into a raw fd it no longer owns (so it can be handed to
+/// `adopt_pty_from_fd`). Currently unused outside tests but kept symmetric.
+pub fn file_into_fd(file: std::fs::File) -> RawFd {
+    file.into_raw_fd()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn session_dir_name_round_trips() {
+        for name in ["default", "work", "a/b/../c", "weird name", "日本語"] {
+            let encoded = session_dir_name(name);
+            assert!(encoded.bytes().all(|b| b.is_ascii_hexdigit()));
+            assert_eq!(decode_session_dir_name(&encoded).as_deref(), Some(name));
+        }
+    }
+
+    #[test]
+    fn decode_rejects_non_hex() {
+        assert!(decode_session_dir_name("zz").is_none());
+        assert!(decode_session_dir_name("abc").is_none());
+    }
+
+    #[test]
+    fn save_and_load_screen_round_trips() {
+        let tmp = tempfile::tempdir().unwrap();
+        let sessions_dir = tmp.path();
+        ensure_runtime_dir(sessions_dir, "work").unwrap();
+        let snap = b"\x1b[?1049lhello world".to_vec();
+        save_screen(sessions_dir, "work", 100, 40, 7, &snap).unwrap();
+        let loaded = load_screen(sessions_dir, "work").expect("screen restored");
+        assert_eq!(loaded.cols, 100);
+        assert_eq!(loaded.rows, 40);
+        assert_eq!(loaded.output_seq, 7);
+        assert_eq!(loaded.snapshot, snap);
+    }
+
+    #[test]
+    fn load_screen_absent_is_none() {
+        let tmp = tempfile::tempdir().unwrap();
+        assert!(load_screen(tmp.path(), "missing").is_none());
+    }
+
+    #[test]
+    fn scan_skips_dead_and_junk_entries() {
+        let tmp = tempfile::tempdir().unwrap();
+        let sessions_dir = tmp.path();
+        // A meta pointing at a definitely-dead pid is cleaned up, not returned.
+        let dir = ensure_runtime_dir(sessions_dir, "ghost").unwrap();
+        write_meta(
+            &dir,
+            &HolderMeta {
+                session: "ghost".to_string(),
+                shell_pid: 2_000_000_000, // not a live pid
+            },
+        )
+        .unwrap();
+        // A junk (non-hex) directory is ignored.
+        std::fs::create_dir_all(runtime_root(sessions_dir).join("not-hex")).unwrap();
+        let found = scan_existing_holders(sessions_dir);
+        assert!(found.is_empty(), "dead/junk holders must be skipped");
+        assert!(!dir.exists(), "dead holder dir should be cleaned up");
+    }
+
+    #[test]
+    fn send_and_recv_fd_round_trips() {
+        use std::io::Seek;
+        // Pass a temp file's fd across a socketpair and confirm both ends point
+        // at the same open file (write via one, read via the other).
+        let (mut a, mut b) = UnixStream::pair().unwrap();
+        let mut file = tempfile::tempfile().unwrap();
+        writeln!(file, "shared-fd-marker").unwrap();
+        file.flush().unwrap();
+        send_fd(&mut a, file.as_raw_fd()).unwrap();
+        let received = recv_fd(&mut b).unwrap();
+        let mut got = fd_into_file(received);
+        got.rewind().unwrap();
+        let mut contents = String::new();
+        got.read_to_string(&mut contents).unwrap();
+        assert!(contents.contains("shared-fd-marker"));
+    }
+}

src/protocol.rs

@@ -3,14 +3,49 @@ use crate::crypto;
 use crate::native::{EnvVar, NativeAuthOk, NativeClientHello, NativeServerHello, NativeUserAuth};
 use anyhow::{Context, Result, bail};
 use serde::{Deserialize, Serialize};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+/// Generate a name for an implicit, ephemeral terminal session — the kind
+/// created by `dosh host` with no `--session`. Single source of truth shared by
+/// the client (which generates it) and the server (which recognizes it via
+/// [`is_implicit_session_name`] to decide a session is NOT worth persisting).
+pub fn generate_implicit_session_name() -> String {
+    let millis = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_millis();
+    format!("term-{millis}-{}", std::process::id())
+}
+
+/// Whether `name` is a client-generated implicit session name
+/// (`term-<digits>-<digits>`). Such sessions are ephemeral: the user can never
+/// reattach by name, so the server must not persist them across restarts.
+/// Explicitly-named (`--session work`) and prewarmed sessions are not implicit.
+pub fn is_implicit_session_name(name: &str) -> bool {
+    let Some(rest) = name.strip_prefix("term-") else {
+        return false;
+    };
+    let mut parts = rest.split('-');
+    match (parts.next(), parts.next(), parts.next()) {
+        (Some(millis), Some(pid), None) => {
+            !millis.is_empty()
+                && millis.bytes().all(|b| b.is_ascii_digit())
+                && !pid.is_empty()
+                && pid.bytes().all(|b| b.is_ascii_digit())
+        }
+        _ => false,
+    }
+}
 
 pub const MAGIC: &[u8; 4] = b"DOSH";
+// v4: added reliable stream offsets/acks to `StreamData` and
+// `StreamWindowAdjust`.
 // v3: added `ForwardingKind::Agent` (SSH-agent forwarding). The new variant rides
 // inside `NativeUserAuth.requested_forwardings`, so a pre-agent peer would fail to
 // deserialize it; bumping the wire version makes such a peer answer with a clear
 // version-mismatch reject instead. Existing variants' bincode discriminants are
 // unchanged, so the bump is purely a compatibility gate.
-pub const VERSION: u8 = 3;
+pub const VERSION: u8 = 4;
 pub const HEADER_LEN: usize = 58;
 
 /// Stable, user-facing reason string the server puts in an `AttachReject` when a
@@ -383,12 +418,14 @@ pub struct StreamOpenReject {
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct StreamData {
     pub stream_id: u64,
+    pub offset: u64,
     pub bytes: Vec<u8>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct StreamWindowAdjust {
     pub stream_id: u64,
+    pub received_offset: u64,
     pub bytes: u32,
 }
 
@@ -496,3 +533,41 @@ impl ReplayWindow {
         }
     }
 }
+
+#[cfg(test)]
+mod session_name_tests {
+    use super::{generate_implicit_session_name, is_implicit_session_name};
+
+    #[test]
+    fn generated_names_are_recognized_as_implicit() {
+        let name = generate_implicit_session_name();
+        assert!(is_implicit_session_name(&name), "generated: {name}");
+    }
+
+    #[test]
+    fn explicit_and_prewarm_names_are_not_implicit() {
+        for name in [
+            "default",
+            "work",
+            "logs",
+            "term",
+            "term-",
+            "term-abc-1",
+            "term-1-x",
+            "term-1",
+            "term-1-2-3",
+            "",
+        ] {
+            assert!(
+                !is_implicit_session_name(name),
+                "should not be implicit: {name:?}"
+            );
+        }
+    }
+
+    #[test]
+    fn implicit_shape_matches() {
+        assert!(is_implicit_session_name("term-1781470634216-76685"));
+        assert!(is_implicit_session_name("term-0-0"));
+    }
+}

src/pty.rs

@@ -1,15 +1,42 @@
 use anyhow::{Context, Result};
 use portable_pty::{Child, CommandBuilder, MasterPty, NativePtySystem, PtySize, PtySystem};
 use std::io::{Read, Write};
-use std::path::Path;
+use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
+use std::path::{Path, PathBuf};
 use std::sync::{Arc, Mutex};
 use std::thread;
 use tokio::sync::mpsc;
 
+// Keep live terminal output comfortably below common path MTUs after Dosh's
+// protocol header, AEAD tag, UDP/IP headers, and bincode framing. Full-screen
+// TUIs often write several KiB on the first draw; sending that as one UDP
+// datagram can fragment and vanish, leaving only a blank alternate screen.
+const PTY_OUTPUT_CHUNK_BYTES: usize = 1024;
+
+/// Backing for a PTY master held by the server.
+///
+/// `Owned` means this process spawned the shell as a child and is responsible
+/// for it: dropping the handle kills the shell. This is the original,
+/// non-persistent model and stays the default.
+///
+/// `Adopted` means the shell lives in a separate holder process and this handle
+/// only borrows the master fd (received over a Unix socket via SCM_RIGHTS).
+/// Dropping it must NOT kill the shell — it just closes our copy of the fd and
+/// stops the reader thread, leaving the holder + shell alive so a server restart
+/// can re-adopt them.
+enum Backing {
+    Owned {
+        child: Mutex<Box<dyn Child + Send + Sync>>,
+        _master: Box<dyn MasterPty + Send>,
+    },
+    Adopted {
+        master: Mutex<std::fs::File>,
+    },
+}
+
 pub struct PtyHandle {
     writer: Arc<Mutex<Box<dyn Write + Send>>>,
-    child: Mutex<Box<dyn Child + Send + Sync>>,
+    backing: Backing,
-    _master: Box<dyn MasterPty + Send>,
 }
 
 impl PtyHandle {
@@ -21,23 +48,40 @@ impl PtyHandle {
     }
 
     pub fn resize(&self, cols: u16, rows: u16) -> Result<()> {
-        self._master.resize(PtySize {
+        match &self.backing {
-            rows,
+            Backing::Owned { _master, .. } => {
-            cols,
+                _master.resize(PtySize {
-            pixel_width: 0,
+                    rows,
-            pixel_height: 0,
+                    cols,
-        })?;
+                    pixel_width: 0,
+                    pixel_height: 0,
+                })?;
+            }
+            Backing::Adopted { master } => {
+                let file = master.lock().expect("pty master poisoned");
+                resize_fd(file.as_raw_fd(), cols, rows)?;
+            }
+        }
         Ok(())
     }
 
+    /// True for a handle backed by a separate holder process. Such a handle must
+    /// be detached (not killed) when the server lets go of a session, so the
+    /// shell survives a server restart.
+    pub fn is_persistent(&self) -> bool {
+        matches!(self.backing, Backing::Adopted { .. })
+    }
+
     /// Terminate the shell process backing this PTY and reap it.
     ///
-    /// Without this the child shell outlives the session: dropping the master
+    /// Only meaningful for an `Owned` backing (the server spawned the shell as a
-    /// alone is not guaranteed to take the process down, and the `Child` handle
+    /// child). For an `Adopted` backing the shell belongs to the holder process,
-    /// used to be discarded at spawn time, which leaked one shell per
+    /// so this is a no-op here; reaping a persistent session is done by asking
-    /// abandoned session.
+    /// the holder to shut down (see `persist::request_shutdown`).
     pub fn kill(&self) {
-        if let Ok(mut child) = self.child.lock() {
+        if let Backing::Owned { child, .. } = &self.backing
+            && let Ok(mut child) = child.lock()
+        {
             let _ = child.kill();
             let _ = child.wait();
         }
@@ -46,10 +90,29 @@ impl PtyHandle {
 
 impl Drop for PtyHandle {
     fn drop(&mut self) {
-        self.kill();
+        // Adopted handles must NOT kill the shell: it lives in the holder so it
+        // can outlive this server. Dropping just closes our fd / stops the
+        // reader. Owned handles keep the original kill-on-drop behavior.
+        if let Backing::Owned { .. } = &self.backing {
+            self.kill();
+        }
     }
 }
 
+fn resize_fd(fd: RawFd, cols: u16, rows: u16) -> Result<()> {
+    let winsize = libc::winsize {
+        ws_row: rows,
+        ws_col: cols,
+        ws_xpixel: 0,
+        ws_ypixel: 0,
+    };
+    let rc = unsafe { libc::ioctl(fd, libc::TIOCSWINSZ, &winsize) };
+    if rc != 0 {
+        return Err(std::io::Error::last_os_error()).context("TIOCSWINSZ");
+    }
+    Ok(())
+}
+
 #[derive(Debug)]
 pub struct PtyOutput {
     pub session: String,
@@ -74,12 +137,82 @@ pub fn spawn_pty_session(
             pixel_height: 0,
         })
         .context("open pty")?;
+    let cmd = build_shell_command(shell, env);
+    let child = pair.slave.spawn_command(cmd).context("spawn shell")?;
+    drop(pair.slave);
+
+    let writer = pair.master.take_writer().context("take pty writer")?;
+    let reader = pair.master.try_clone_reader().context("clone pty reader")?;
+    spawn_reader_thread(session, reader, tx)?;
+
+    Ok(PtyHandle {
+        writer: Arc::new(Mutex::new(writer)),
+        backing: Backing::Owned {
+            child: Mutex::new(child),
+            _master: pair.master,
+        },
+    })
+}
+
+/// Whether this host has a terminfo entry for `term`, searching the standard
+/// ncurses directories. Both the legacy single-letter (`x/xterm`) and the
+/// hashed (`78/xterm`) subdirectory layouts are checked.
+fn terminfo_available(term: &str) -> bool {
+    let Some(first) = term.chars().next() else {
+        return false;
+    };
+    let letter = first.to_string();
+    let hashed = format!("{:x}", first as u32);
+    let mut dirs: Vec<PathBuf> = Vec::new();
+    if let Ok(t) = std::env::var("TERMINFO")
+        && !t.is_empty()
+    {
+        dirs.push(PathBuf::from(t));
+    }
+    if let Some(home) = dirs::home_dir() {
+        dirs.push(home.join(".terminfo"));
+    }
+    if let Ok(td) = std::env::var("TERMINFO_DIRS") {
+        for d in td.split(':').filter(|d| !d.is_empty()) {
+            dirs.push(PathBuf::from(d));
+        }
+    }
+    for d in [
+        "/etc/terminfo",
+        "/lib/terminfo",
+        "/usr/share/terminfo",
+        "/usr/lib/terminfo",
+        "/usr/share/lib/terminfo",
+    ] {
+        dirs.push(PathBuf::from(d));
+    }
+    dirs.iter()
+        .any(|dir| dir.join(&letter).join(term).exists() || dir.join(&hashed).join(term).exists())
+}
+
+/// Build the [`CommandBuilder`] for a dosh shell, identically for the in-process
+/// `spawn_pty_session` and the out-of-process holder, so a persistent session's
+/// environment matches a non-persistent one.
+pub fn build_shell_command(shell: &str, env: &[(String, String)]) -> CommandBuilder {
     let mut cmd = CommandBuilder::new(shell);
-    cmd.env("TERM", "xterm-256color");
     cmd.env("COLORTERM", "truecolor");
     for (name, value) in env {
         cmd.env(name, value);
     }
+    // The client's TERM is propagated, but a server that lacks that terminal's
+    // terminfo entry (e.g. xterm-ghostty, xterm-kitty) breaks ncurses apps like
+    // tmux/vim with "missing or unsuitable terminal". Keep the requested TERM
+    // only when this host actually has its terminfo; otherwise fall back to a
+    // universally available entry so remote apps always work.
+    let term = match env
+        .iter()
+        .find(|(n, _)| n == "TERM")
+        .map(|(_, v)| v.as_str())
+    {
+        Some(requested) if terminfo_available(requested) => requested.to_string(),
+        _ => "xterm-256color".to_string(),
+    };
+    cmd.env("TERM", term);
     cmd.env("SHELL", shell);
     if let Some(home) = dirs::home_dir() {
         cmd.env("HOME", home.as_os_str());
@@ -88,11 +221,39 @@ pub fn spawn_pty_session(
     } else if let Some(parent) = Path::new(shell).parent() {
         cmd.env("PWD", parent.as_os_str());
     }
-    let child = pair.slave.spawn_command(cmd).context("spawn shell")?;
+    cmd
-    drop(pair.slave);
+}
 
-    let writer = pair.master.take_writer().context("take pty writer")?;
+/// Build a [`PtyHandle`] from a master fd received from a holder process.
-    let mut reader = pair.master.try_clone_reader().context("clone pty reader")?;
+///
+/// `master_fd` is an fd this handle takes ownership of (it is wrapped in a
+/// `File` and closed on drop). The shell is NOT a child of this process; it
+/// belongs to the holder, so dropping this handle leaves it running.
+pub fn adopt_pty_from_fd(
+    session: String,
+    master_fd: RawFd,
+    tx: mpsc::UnboundedSender<PtyOutput>,
+) -> Result<PtyHandle> {
+    // Take ownership of the fd. A clone gives us an independent reader so the
+    // reader thread and the writer/resize side hold separate `File`s and don't
+    // get closed out from under each other.
+    let master = unsafe { std::fs::File::from_raw_fd(master_fd) };
+    let reader_file = master.try_clone().context("clone master for reader")?;
+    let writer_file = master.try_clone().context("clone master for writer")?;
+    spawn_reader_thread(session, Box::new(reader_file), tx)?;
+    Ok(PtyHandle {
+        writer: Arc::new(Mutex::new(Box::new(writer_file))),
+        backing: Backing::Adopted {
+            master: Mutex::new(master),
+        },
+    })
+}
+
+fn spawn_reader_thread(
+    session: String,
+    mut reader: Box<dyn Read + Send>,
+    tx: mpsc::UnboundedSender<PtyOutput>,
+) -> Result<()> {
     let reader_session = session.clone();
     thread::Builder::new()
         .name(format!("dosh-pty-{session}"))
@@ -109,11 +270,13 @@ pub fn spawn_pty_session(
                         break;
                     }
                     Ok(n) => {
-                        let _ = tx.send(PtyOutput {
+                        for chunk in buf[..n].chunks(PTY_OUTPUT_CHUNK_BYTES) {
-                            session: reader_session.clone(),
+                            let _ = tx.send(PtyOutput {
-                            bytes: buf[..n].to_vec(),
+                                session: reader_session.clone(),
-                            exited: false,
+                                bytes: chunk.to_vec(),
-                        });
+                                exited: false,
+                            });
+                        }
                     }
                     Err(_) => {
                         let _ = tx.send(PtyOutput {
@@ -127,10 +290,24 @@ pub fn spawn_pty_session(
             }
         })
         .context("spawn pty reader")?;
+    Ok(())
+}
 
-    Ok(PtyHandle {
+#[cfg(test)]
-        writer: Arc::new(Mutex::new(writer)),
+mod tests {
-        child: Mutex::new(child),
+    use super::*;
-        _master: pair.master,
+
-    })
+    #[test]
+    fn terminfo_available_detects_known_and_unknown() {
+        // A near-universal entry should be present on any host with ncurses.
+        assert!(terminfo_available("xterm") || terminfo_available("xterm-256color"));
+        // Bogus / empty names must report missing so we fall back.
+        assert!(!terminfo_available("definitely-not-a-real-terminal-xyz"));
+        assert!(!terminfo_available(""));
+    }
+
+    #[test]
+    fn pty_output_chunk_size_stays_mtu_safe() {
+        assert!(PTY_OUTPUT_CHUNK_BYTES <= 1200);
+    }
 }

src/ssh_agent.rs

@@ -1,6 +1,6 @@
 use crate::native::{
     ForwardingRequest, NativeClientHello, NativeServerHello, NativeUserAuth,
-    parse_ssh_ed25519_public_blob, user_auth_transcript,
+    is_supported_user_key_algorithm, parse_ssh_ed25519_public_blob, user_auth_transcript,
 };
 use anyhow::{Context, Result, anyhow, bail};
 use std::io::{Read, Write};
@@ -12,12 +12,16 @@ const SSH2_AGENTC_REQUEST_IDENTITIES: u8 = 11;
 const SSH2_AGENT_IDENTITIES_ANSWER: u8 = 12;
 const SSH2_AGENTC_SIGN_REQUEST: u8 = 13;
 const SSH2_AGENT_SIGN_RESPONSE: u8 = 14;
+const SSH_AGENT_RSA_SHA2_512: u32 = 4;
 const MAX_AGENT_PACKET: usize = 256 * 1024;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct AgentIdentity {
     pub key_blob: Vec<u8>,
-    pub public_key: [u8; 32],
+    pub public_key_algorithm: String,
+    pub public_key: Vec<u8>,
+    pub sign_algorithm: String,
+    pub sign_flags: u32,
     pub comment: String,
 }
 
@@ -38,13 +42,13 @@ pub fn sign_user_auth_with_agent_at(
 ) -> Result<NativeUserAuth> {
     let mut agent = UnixStream::connect(socket_path.as_ref())
         .with_context(|| format!("connect ssh-agent {}", socket_path.as_ref().display()))?;
-    let identities = request_ed25519_identities(&mut agent)?;
+    let identities = request_supported_identities(&mut agent)?;
     let identity = identities
         .first()
-        .ok_or_else(|| anyhow!("ssh-agent has no ssh-ed25519 identities"))?;
+        .ok_or_else(|| anyhow!("ssh-agent has no supported identities"))?;
     let mut auth = NativeUserAuth {
-        public_key_algorithm: "ssh-ed25519".to_string(),
+        public_key_algorithm: identity.sign_algorithm.clone(),
-        public_key: identity.public_key.to_vec(),
+        public_key: identity.public_key.clone(),
         signature: Vec::new(),
         requested_forwardings,
     };
@@ -54,7 +58,7 @@ pub fn sign_user_auth_with_agent_at(
     Ok(auth)
 }
 
-fn request_ed25519_identities(agent: &mut UnixStream) -> Result<Vec<AgentIdentity>> {
+fn request_supported_identities(agent: &mut UnixStream) -> Result<Vec<AgentIdentity>> {
     write_agent_packet(agent, &[SSH2_AGENTC_REQUEST_IDENTITIES])?;
     let payload = read_agent_packet(agent)?;
     let mut cursor = payload.as_slice();
@@ -72,18 +76,49 @@ fn request_ed25519_identities(agent: &mut UnixStream) -> Result<Vec<AgentIdentit
     for _ in 0..count {
         let key_blob = read_ssh_string(&mut cursor)?.to_vec();
         let comment = String::from_utf8_lossy(read_ssh_string(&mut cursor)?).to_string();
-        if let Ok(public_key) = parse_ssh_ed25519_public_blob(&key_blob) {
+        if let Some(identity) = supported_identity(key_blob, comment)? {
-            identities.push(AgentIdentity {
+            identities.push(identity);
-                key_blob,
-                public_key,
-                comment,
-            });
         }
     }
     anyhow::ensure!(cursor.is_empty(), "trailing data in ssh-agent identities");
     Ok(identities)
 }
 
+fn supported_identity(key_blob: Vec<u8>, comment: String) -> Result<Option<AgentIdentity>> {
+    let algorithm = key_blob_algorithm(&key_blob)?;
+    if !is_supported_user_key_algorithm(&algorithm) {
+        return Ok(None);
+    }
+    let identity = match algorithm.as_str() {
+        "ssh-ed25519" => AgentIdentity {
+            public_key_algorithm: algorithm.clone(),
+            public_key: parse_ssh_ed25519_public_blob(&key_blob)?.to_vec(),
+            sign_algorithm: "ssh-ed25519".to_string(),
+            sign_flags: 0,
+            key_blob,
+            comment,
+        },
+        "ecdsa-sha2-nistp256" => AgentIdentity {
+            public_key_algorithm: algorithm.clone(),
+            public_key: key_blob.clone(),
+            sign_algorithm: algorithm,
+            sign_flags: 0,
+            key_blob,
+            comment,
+        },
+        "ssh-rsa" => AgentIdentity {
+            public_key_algorithm: algorithm,
+            public_key: key_blob.clone(),
+            sign_algorithm: "rsa-sha2-512".to_string(),
+            sign_flags: SSH_AGENT_RSA_SHA2_512,
+            key_blob,
+            comment,
+        },
+        _ => return Ok(None),
+    };
+    Ok(Some(identity))
+}
+
 fn sign_with_agent(
     agent: &mut UnixStream,
     identity: &AgentIdentity,
@@ -93,7 +128,7 @@ fn sign_with_agent(
     request.push(SSH2_AGENTC_SIGN_REQUEST);
     write_ssh_string(&mut request, &identity.key_blob);
     write_ssh_string(&mut request, transcript);
-    request.extend_from_slice(&0u32.to_be_bytes());
+    request.extend_from_slice(&identity.sign_flags.to_be_bytes());
     write_agent_packet(agent, &request)?;
 
     let payload = read_agent_packet(agent)?;
@@ -114,20 +149,17 @@ fn sign_with_agent(
 
     let mut signature_cursor = signature_blob;
     let algorithm = read_ssh_string(&mut signature_cursor)?;
+    let algorithm = String::from_utf8_lossy(algorithm);
     anyhow::ensure!(
-        algorithm == b"ssh-ed25519",
+        algorithm == identity.sign_algorithm,
-        "ssh-agent returned unsupported signature algorithm {}",
+        "ssh-agent returned signature algorithm {algorithm}, expected {}",
-        String::from_utf8_lossy(algorithm)
+        identity.sign_algorithm
     );
     let signature = read_ssh_string(&mut signature_cursor)?;
     anyhow::ensure!(
         signature_cursor.is_empty(),
         "trailing data in ssh-agent signature blob"
     );
-    anyhow::ensure!(
-        signature.len() == 64,
-        "ssh-agent Ed25519 signature was not 64 bytes"
-    );
     Ok(signature.to_vec())
 }
 
@@ -182,6 +214,12 @@ fn write_ssh_string(out: &mut Vec<u8>, value: &[u8]) {
     out.extend_from_slice(value);
 }
 
+fn key_blob_algorithm(blob: &[u8]) -> Result<String> {
+    let mut cursor = blob;
+    let algorithm = read_ssh_string(&mut cursor)?;
+    Ok(String::from_utf8_lossy(algorithm).to_string())
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -253,8 +291,8 @@ mod tests {
             protocol_version: crate::native::NATIVE_PROTOCOL_VERSION,
             client_random: [1u8; 32],
             client_ephemeral_public: [2u8; 32],
-            requested_host: "palav".to_string(),
+            requested_host: "homelab".to_string(),
-            requested_user: "palav".to_string(),
+            requested_user: "alice".to_string(),
             requested_session: "term".to_string(),
             requested_mode: "read-write".to_string(),
             terminal_size: (80, 24),

tests/hostile_network.rs

@@ -20,7 +20,8 @@
 //! tests are reproducible and fast.
 
 use std::fs;
-use std::net::{SocketAddr, UdpSocket};
+use std::io::{Read, Write};
+use std::net::{SocketAddr, TcpListener, UdpSocket};
 use std::process::{Child, Command, Stdio};
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
@@ -28,13 +29,18 @@ use std::sync::mpsc::{Receiver, Sender, channel};
 use std::thread;
 use std::time::{Duration, Instant};
 
+use base64::Engine;
+use base64::engine::general_purpose::STANDARD;
 use dosh::auth::{BootstrapResponse, build_bootstrap, load_or_create_server_secret};
 use dosh::config::load_server_config;
 use dosh::crypto;
+use dosh::native::{self, ForwardingKind, ForwardingRequest, NativeAuthOk, NativeClientHello};
 use dosh::protocol::{
-    self, AttachOk, CLIENT_TO_SERVER, Frame, Header, Input, PacketKind, ResumeRequest,
+    self, AttachOk, AttachReject, CLIENT_TO_SERVER, Frame, Header, Input, NativeAuthOkBody,
-    SERVER_TO_CLIENT,
+    NativeClientHelloBody, NativeServerHelloBody, NativeUserAuthBody, PacketKind, ResumeRequest,
+    SERVER_TO_CLIENT, StreamData, StreamOpen, StreamOpenOk, StreamWindowAdjust,
 };
+use ed25519_dalek::{SigningKey, VerifyingKey};
 use rand::rngs::StdRng;
 use rand::{Rng, SeedableRng};
 
@@ -67,6 +73,7 @@ sessions_dir = "{sessions}"
 secret_path = "{secret}"
 host_key = "{host_key}"
 authorized_keys = ["{authorized_keys}"]
+persist_sessions = false
 "#,
             sessions = dir.path().join("sessions").display(),
             secret = dir.path().join("secret").display(),
@@ -78,6 +85,23 @@ authorized_keys = ["{authorized_keys}"]
     config
 }
 
+fn authorize_ed25519_key(dir: &tempfile::TempDir, signing_key: &SigningKey) {
+    let verifying = VerifyingKey::from(signing_key);
+    let mut blob = Vec::new();
+    write_ssh_string(&mut blob, b"ssh-ed25519");
+    write_ssh_string(&mut blob, verifying.as_bytes());
+    fs::write(
+        dir.path().join("authorized_keys"),
+        format!("ssh-ed25519 {} hostile-test\n", STANDARD.encode(blob)),
+    )
+    .unwrap();
+}
+
+fn write_ssh_string(out: &mut Vec<u8>, value: &[u8]) {
+    out.extend_from_slice(&(value.len() as u32).to_be_bytes());
+    out.extend_from_slice(value);
+}
+
 fn start_server(dir: &tempfile::TempDir, config: &std::path::Path) -> Child {
     let server = env!("CARGO_BIN_EXE_dosh-server");
     let child = Command::new(server)
@@ -401,6 +425,122 @@ fn attach_through_relay(
     }
 }
 
+struct NativeAttached {
+    socket: UdpSocket,
+    ok: NativeAuthOk,
+}
+
+fn native_attach_through_relay(
+    relay: &Relay,
+    signing_key: &SigningKey,
+    requested_forwardings: Vec<ForwardingRequest>,
+) -> NativeAttached {
+    let socket = UdpSocket::bind("127.0.0.1:0").unwrap();
+    socket
+        .set_read_timeout(Some(Duration::from_millis(500)))
+        .unwrap();
+    let (client_secret, client_public) = native::generate_native_ephemeral();
+    let hello = NativeClientHello {
+        protocol_version: native::NATIVE_PROTOCOL_VERSION,
+        client_random: crypto::random_32(),
+        client_ephemeral_public: client_public,
+        requested_host: "127.0.0.1".to_string(),
+        requested_user: std::env::var("USER").unwrap_or_else(|_| "unknown".to_string()),
+        requested_session: "default".to_string(),
+        requested_mode: "read-write".to_string(),
+        terminal_size: (80, 24),
+        supported_aead: vec!["chacha20poly1305".to_string()],
+        supported_user_key_algorithms: native::supported_user_key_algorithms(),
+        cached_host_key_fingerprint: None,
+        attach_ticket_envelope: None,
+        requested_env: Vec::new(),
+    };
+    let packet = protocol::encode_plain(
+        PacketKind::NativeClientHello,
+        [0u8; 16],
+        1,
+        0,
+        &protocol::to_body(&NativeClientHelloBody {
+            hello: hello.clone(),
+        })
+        .unwrap(),
+    )
+    .unwrap();
+    let hello_deadline = Instant::now() + Duration::from_secs(5);
+    let server_hello = loop {
+        socket.send_to(&packet, relay.front_addr()).unwrap();
+        let mut buf = [0u8; 65535];
+        match socket.recv_from(&mut buf) {
+            Ok((n, _)) => {
+                let packet = protocol::decode(&buf[..n]).unwrap();
+                match packet.header.kind {
+                    PacketKind::NativeServerHello => {
+                        let body: NativeServerHelloBody =
+                            protocol::from_body(&packet.body).unwrap();
+                        native::verify_server_hello(&hello, &body.hello).unwrap();
+                        break body.hello;
+                    }
+                    PacketKind::AttachReject => {
+                        let reject: AttachReject = protocol::from_body(&packet.body).unwrap();
+                        panic!("native hello rejected: {}", reject.reason);
+                    }
+                    kind => panic!("unexpected native hello response: {kind:?}"),
+                }
+            }
+            Err(_) if Instant::now() < hello_deadline => {}
+            Err(err) => panic!("native server hello timed out: {err}"),
+        }
+    };
+
+    let session_key = native::derive_native_session_key(
+        &client_secret,
+        server_hello.server_ephemeral_public,
+        &hello,
+        &server_hello,
+    )
+    .unwrap();
+    let auth =
+        native::sign_user_auth(signing_key, &hello, &server_hello, requested_forwardings).unwrap();
+    let mut pending_id = [0u8; 16];
+    pending_id.copy_from_slice(&server_hello.auth_challenge[..16]);
+    let auth_packet = protocol::encode_encrypted(
+        PacketKind::NativeUserAuth,
+        pending_id,
+        2,
+        1,
+        &session_key,
+        CLIENT_TO_SERVER,
+        &protocol::to_body(&NativeUserAuthBody { auth }).unwrap(),
+    )
+    .unwrap();
+    let auth_deadline = Instant::now() + Duration::from_secs(5);
+    let ok = loop {
+        socket.send_to(&auth_packet, relay.front_addr()).unwrap();
+        let mut buf = [0u8; 65535];
+        match socket.recv_from(&mut buf) {
+            Ok((n, _)) => {
+                let packet = protocol::decode(&buf[..n]).unwrap();
+                match packet.header.kind {
+                    PacketKind::NativeAuthOk => {
+                        let plain = protocol::decrypt_body(&packet, &session_key, SERVER_TO_CLIENT)
+                            .unwrap();
+                        let body: NativeAuthOkBody = protocol::from_body(&plain).unwrap();
+                        break body.ok;
+                    }
+                    PacketKind::AttachReject => {
+                        let reject: AttachReject = protocol::from_body(&packet.body).unwrap();
+                        panic!("native auth rejected: {}", reject.reason);
+                    }
+                    kind => panic!("unexpected native auth response: {kind:?}"),
+                }
+            }
+            Err(_) if Instant::now() < auth_deadline => {}
+            Err(err) => panic!("native auth ok timed out: {err}"),
+        }
+    };
+    NativeAttached { socket, ok }
+}
+
 fn send_input(
     socket: &UdpSocket,
     relay: &Relay,
@@ -430,6 +570,152 @@ fn send_raw(socket: &UdpSocket, relay: &Relay, packet: &[u8]) {
     socket.send_to(packet, relay.front_addr()).unwrap();
 }
 
+fn send_stream_packet(
+    socket: &UdpSocket,
+    relay: &Relay,
+    ok: &NativeAuthOk,
+    kind: PacketKind,
+    seq: u64,
+    ack: u64,
+    body: Vec<u8>,
+) {
+    let packet = protocol::encode_encrypted(
+        kind,
+        ok.client_id,
+        seq,
+        ack,
+        &ok.session_key,
+        CLIENT_TO_SERVER,
+        &body,
+    )
+    .unwrap();
+    socket.send_to(&packet, relay.front_addr()).unwrap();
+}
+
+fn recv_stream_packet<T: serde::de::DeserializeOwned>(
+    socket: &UdpSocket,
+    key: &[u8; 32],
+    kind: PacketKind,
+) -> Option<(Header, T)> {
+    let mut buf = [0u8; 65535];
+    let (n, _) = socket.recv_from(&mut buf).ok()?;
+    let packet = protocol::decode(&buf[..n]).ok()?;
+    if packet.header.kind != kind {
+        return None;
+    }
+    let plain = protocol::decrypt_body(&packet, key, SERVER_TO_CLIENT).ok()?;
+    let body = protocol::from_body(&plain).ok()?;
+    Some((packet.header, body))
+}
+
+fn wait_for_stream_open_ok(
+    socket: &UdpSocket,
+    key: &[u8; 32],
+    stream_id: u64,
+    millis: u64,
+) -> Option<Header> {
+    let deadline = Instant::now() + Duration::from_millis(millis);
+    while Instant::now() < deadline {
+        if let Some((header, ok)) =
+            recv_stream_packet::<StreamOpenOk>(socket, key, PacketKind::StreamOpenOk)
+        {
+            if ok.stream_id == stream_id {
+                return Some(header);
+            }
+        }
+    }
+    None
+}
+
+fn wait_for_stream_data(
+    socket: &UdpSocket,
+    key: &[u8; 32],
+    stream_id: u64,
+    millis: u64,
+) -> Option<(Header, StreamData)> {
+    let deadline = Instant::now() + Duration::from_millis(millis);
+    while Instant::now() < deadline {
+        if let Some((header, data)) =
+            recv_stream_packet::<StreamData>(socket, key, PacketKind::StreamData)
+        {
+            if data.stream_id == stream_id {
+                return Some((header, data));
+            }
+        }
+    }
+    None
+}
+
+fn start_tcp_collector() -> (u16, Receiver<Vec<u8>>) {
+    let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+    let port = listener.local_addr().unwrap().port();
+    let (tx, rx) = channel();
+    thread::spawn(move || {
+        let Ok((mut stream, _)) = listener.accept() else {
+            return;
+        };
+        stream
+            .set_read_timeout(Some(Duration::from_millis(100)))
+            .unwrap();
+        let deadline = Instant::now() + Duration::from_secs(5);
+        let mut buf = [0u8; 1024];
+        while Instant::now() < deadline {
+            match stream.read(&mut buf) {
+                Ok(0) => return,
+                Ok(n) => {
+                    let _ = tx.send(buf[..n].to_vec());
+                }
+                Err(ref err)
+                    if err.kind() == std::io::ErrorKind::WouldBlock
+                        || err.kind() == std::io::ErrorKind::TimedOut => {}
+                Err(_) => return,
+            }
+        }
+    });
+    (port, rx)
+}
+
+fn start_tcp_echo() -> u16 {
+    let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+    let port = listener.local_addr().unwrap().port();
+    thread::spawn(move || {
+        let Ok((mut stream, _)) = listener.accept() else {
+            return;
+        };
+        stream
+            .set_read_timeout(Some(Duration::from_millis(100)))
+            .unwrap();
+        let deadline = Instant::now() + Duration::from_secs(5);
+        let mut buf = [0u8; 1024];
+        while Instant::now() < deadline {
+            match stream.read(&mut buf) {
+                Ok(0) => return,
+                Ok(n) => {
+                    let _ = stream.write_all(&buf[..n]);
+                }
+                Err(ref err)
+                    if err.kind() == std::io::ErrorKind::WouldBlock
+                        || err.kind() == std::io::ErrorKind::TimedOut => {}
+                Err(_) => return,
+            }
+        }
+    });
+    port
+}
+
+fn collect_tcp(rx: &Receiver<Vec<u8>>, millis: u64) -> Vec<u8> {
+    let deadline = Instant::now() + Duration::from_millis(millis);
+    let mut out = Vec::new();
+    while Instant::now() < deadline {
+        match rx.recv_timeout(Duration::from_millis(50)) {
+            Ok(chunk) => out.extend_from_slice(&chunk),
+            Err(std::sync::mpsc::RecvTimeoutError::Timeout) => {}
+            Err(std::sync::mpsc::RecvTimeoutError::Disconnected) => break,
+        }
+    }
+    out
+}
+
 fn recv_frame(socket: &UdpSocket, key: &[u8; 32]) -> Option<(Header, Frame)> {
     let mut buf = [0u8; 65535];
     let (n, _) = socket.recv_from(&mut buf).ok()?;
@@ -602,6 +888,215 @@ fn duplicated_and_replayed_input_is_applied_at_most_once() {
     );
 }
 
+#[test]
+fn forwarded_stream_data_survives_reorder_and_rejects_replay() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    let signing_key = SigningKey::from_bytes(&[42u8; 32]);
+    authorize_ed25519_key(&dir, &signing_key);
+    let (target_port, tcp_rx) = start_tcp_collector();
+    let mut server = start_server(&dir, &config);
+    let relay = Relay::spawn(port, 0xF0E0D0u64);
+
+    let attached = native_attach_through_relay(
+        &relay,
+        &signing_key,
+        vec![ForwardingRequest {
+            kind: ForwardingKind::Local,
+            bind_host: Some("127.0.0.1".to_string()),
+            listen_port: 0,
+            target_host: Some("127.0.0.1".to_string()),
+            target_port: Some(target_port),
+        }],
+    );
+    let stream_id = 44;
+    let open = StreamOpen {
+        stream_id,
+        target_host: "127.0.0.1".to_string(),
+        target_port,
+    };
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamOpen,
+        3,
+        attached.ok.initial_seq,
+        protocol::to_body(&open).unwrap(),
+    );
+    let open_ok =
+        wait_for_stream_open_ok(&attached.socket, &attached.ok.session_key, stream_id, 3000)
+            .expect("stream did not open");
+
+    // Swap the first two StreamData packets in flight. The server's replay
+    // window must accept both out-of-order packets and write both to the TCP
+    // target exactly once.
+    relay.arm_reorder();
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamData,
+        4,
+        open_ok.seq,
+        protocol::to_body(&StreamData {
+            stream_id,
+            offset: 0,
+            bytes: b"A".to_vec(),
+        })
+        .unwrap(),
+    );
+    relay.arm_reorder();
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamData,
+        5,
+        open_ok.seq,
+        protocol::to_body(&StreamData {
+            stream_id,
+            offset: 1,
+            bytes: b"B".to_vec(),
+        })
+        .unwrap(),
+    );
+
+    let mut seen = collect_tcp(&tcp_rx, 1500);
+    assert!(
+        seen.starts_with(b"AB"),
+        "reordered stream bytes were not delivered once in-order to TCP target: {:?}",
+        String::from_utf8_lossy(&seen)
+    );
+
+    // Now send one encrypted StreamData packet repeatedly, with relay-level
+    // duplication enabled too. This is a true replay: same sequence, same nonce,
+    // same ciphertext. It must be applied to the TCP target at most once.
+    let replayed = protocol::encode_encrypted(
+        PacketKind::StreamData,
+        attached.ok.client_id,
+        6,
+        open_ok.seq,
+        &attached.ok.session_key,
+        CLIENT_TO_SERVER,
+        &protocol::to_body(&StreamData {
+            stream_id,
+            offset: 2,
+            bytes: b"X".to_vec(),
+        })
+        .unwrap(),
+    )
+    .unwrap();
+    relay.set_dup(100);
+    for _ in 0..12 {
+        send_raw(&attached.socket, &relay, &replayed);
+        thread::sleep(Duration::from_millis(25));
+    }
+    relay.set_dup(0);
+
+    seen.extend(collect_tcp(&tcp_rx, 1500));
+    let replay_count = seen.iter().filter(|byte| **byte == b'X').count();
+
+    drop(relay);
+    let _ = server.kill();
+    let _ = server.wait();
+
+    assert!(
+        replay_count <= 1,
+        "replayed/duplicated StreamData was applied {replay_count} times: {:?}",
+        String::from_utf8_lossy(&seen)
+    );
+}
+
+#[test]
+fn forwarded_stream_data_recovers_after_server_to_client_loss() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    let signing_key = SigningKey::from_bytes(&[43u8; 32]);
+    authorize_ed25519_key(&dir, &signing_key);
+    let target_port = start_tcp_echo();
+    let mut server = start_server(&dir, &config);
+    let relay = Relay::spawn(port, 0xA11CEu64);
+
+    let attached = native_attach_through_relay(
+        &relay,
+        &signing_key,
+        vec![ForwardingRequest {
+            kind: ForwardingKind::Local,
+            bind_host: Some("127.0.0.1".to_string()),
+            listen_port: 0,
+            target_host: Some("127.0.0.1".to_string()),
+            target_port: Some(target_port),
+        }],
+    );
+    let stream_id = 55;
+    let open = StreamOpen {
+        stream_id,
+        target_host: "127.0.0.1".to_string(),
+        target_port,
+    };
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamOpen,
+        3,
+        attached.ok.initial_seq,
+        protocol::to_body(&open).unwrap(),
+    );
+    let open_ok =
+        wait_for_stream_open_ok(&attached.socket, &attached.ok.session_key, stream_id, 3000)
+            .expect("stream did not open");
+
+    // Drop the first server->client echo and at least one retransmit tick. Once
+    // the link clears, the unacked stream chunk must be re-encrypted with a new
+    // packet sequence and delivered at the same stream offset.
+    relay.set_drop_s2c(100);
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamData,
+        4,
+        open_ok.seq,
+        protocol::to_body(&StreamData {
+            stream_id,
+            offset: 0,
+            bytes: b"PING".to_vec(),
+        })
+        .unwrap(),
+    );
+    thread::sleep(Duration::from_millis(300));
+    relay.set_drop_s2c(0);
+
+    let (_header, data) =
+        wait_for_stream_data(&attached.socket, &attached.ok.session_key, stream_id, 3000)
+            .expect("lost server->client stream data was not retransmitted");
+    assert_eq!(data.offset, 0);
+    assert_eq!(data.bytes, b"PING");
+
+    send_stream_packet(
+        &attached.socket,
+        &relay,
+        &attached.ok,
+        PacketKind::StreamWindowAdjust,
+        5,
+        open_ok.seq,
+        protocol::to_body(&StreamWindowAdjust {
+            stream_id,
+            received_offset: 4,
+            bytes: 4,
+        })
+        .unwrap(),
+    );
+
+    drop(relay);
+    let _ = server.kill();
+    let _ = server.wait();
+}
+
 #[test]
 fn stale_packets_after_resume_are_ignored_not_fatal() {
     let dir = tempfile::tempdir().unwrap();

tests/integration_smoke.rs

@@ -4,6 +4,7 @@ use std::net::{TcpListener, TcpStream, UdpSocket};
 use std::os::unix::net::{UnixListener, UnixStream};
 use std::path::{Path, PathBuf};
 use std::process::{Child, Command, Stdio};
+use std::sync::mpsc;
 use std::thread;
 use std::time::Duration;
 
@@ -83,6 +84,7 @@ sessions_dir = "{sessions}"
 secret_path = "{secret}"
 host_key = "{host_key}"
 authorized_keys = ["{authorized_keys}"]
+persist_sessions = false
 "#,
             sessions = dir.path().join("sessions").display(),
             secret = dir.path().join("secret").display(),
@@ -233,6 +235,37 @@ fn start_echo_server() -> u16 {
     port
 }
 
+fn start_slow_sink_server() -> u16 {
+    let listener = TcpListener::bind("127.0.0.1:0").unwrap();
+    let port = listener.local_addr().unwrap().port();
+    thread::spawn(move || {
+        if let Ok((mut stream, _)) = listener.accept() {
+            let mut buf = [0u8; 8192];
+            loop {
+                match stream.read(&mut buf) {
+                    Ok(0) | Err(_) => break,
+                    Ok(_) => thread::sleep(Duration::from_millis(20)),
+                }
+            }
+        }
+    });
+    port
+}
+
+fn connect_with_retry_no_child(port: u16, timeout: Duration) -> TcpStream {
+    let deadline = std::time::Instant::now() + timeout;
+    loop {
+        match TcpStream::connect(("127.0.0.1", port)) {
+            Ok(stream) => return stream,
+            Err(err) if std::time::Instant::now() < deadline => {
+                let _ = err;
+                thread::sleep(Duration::from_millis(50));
+            }
+            Err(err) => panic!("connect to local forward 127.0.0.1:{port}: {err}"),
+        }
+    }
+}
+
 fn write_native_client_auth(dir: &tempfile::TempDir, config_path: &std::path::Path) {
     write_native_client_auth_with_options(dir, config_path, "");
 }
@@ -413,6 +446,15 @@ fn direct_attach(
     config: &std::path::Path,
     port: u16,
     mode: &str,
+) -> (std::net::UdpSocket, dosh::auth::BootstrapResponse, AttachOk) {
+    direct_attach_session(config, port, mode, "default")
+}
+
+fn direct_attach_session(
+    config: &std::path::Path,
+    port: u16,
+    mode: &str,
+    session: &str,
 ) -> (std::net::UdpSocket, dosh::auth::BootstrapResponse, AttachOk) {
     let config = load_server_config(Some(config.to_path_buf())).unwrap();
     let secret = load_or_create_server_secret(&config).unwrap();
@@ -420,7 +462,7 @@ fn direct_attach(
         &config,
         &secret,
         "tester".to_string(),
-        "default".to_string(),
+        session.to_string(),
         mode.to_string(),
         (80, 24),
         crypto::random_12(),
@@ -781,6 +823,106 @@ fn native_local_forward_background_smoke() {
     assert_eq!(&buf[..n], b"dosh-background-forward-ping");
 }
 
+#[test]
+fn native_local_forward_bulk_load_does_not_delay_interactive_terminal() {
+    use portable_pty::{CommandBuilder, NativePtySystem, PtySize, PtySystem};
+
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    write_native_client_auth(&dir, &config);
+    let sink_port = start_slow_sink_server();
+    let local_port = free_tcp_port();
+    let mut server = start_server(&dir, &config);
+
+    let pty = NativePtySystem::default();
+    let pair = pty
+        .openpty(PtySize {
+            rows: 24,
+            cols: 80,
+            pixel_width: 0,
+            pixel_height: 0,
+        })
+        .unwrap();
+    let mut reader = pair.master.try_clone_reader().unwrap();
+    let mut writer = pair.master.take_writer().unwrap();
+
+    let client_bin = env!("CARGO_BIN_EXE_dosh-client");
+    let mut cmd = CommandBuilder::new(client_bin);
+    let forward_arg = format!("{local_port}:127.0.0.1:{sink_port}");
+    let dosh_port = port.to_string();
+    cmd.args([
+        "--auth",
+        "native",
+        "--no-cache",
+        "-L",
+        &forward_arg,
+        "--session",
+        "load-session",
+        "--dosh-host",
+        "127.0.0.1",
+        "--dosh-port",
+        &dosh_port,
+        "local",
+    ]);
+    cmd.env("HOME", dir.path().to_string_lossy().to_string());
+    let mut child = pair.slave.spawn_command(cmd).unwrap();
+    drop(pair.slave);
+
+    let mut forward_stream = connect_with_retry_no_child(local_port, Duration::from_secs(5));
+    let bulk_writer = thread::spawn(move || {
+        let chunk = vec![b'x'; 8192];
+        for _ in 0..128 {
+            if forward_stream.write_all(&chunk).is_err() {
+                break;
+            }
+        }
+    });
+
+    let (seen_tx, seen_rx) = mpsc::channel();
+    let reader_handle = thread::spawn(move || {
+        let mut buf = [0u8; 4096];
+        let mut output = Vec::new();
+        loop {
+            match reader.read(&mut buf) {
+                Ok(0) | Err(_) => break,
+                Ok(n) => {
+                    output.extend_from_slice(&buf[..n]);
+                    if output
+                        .windows(b"DOSH_LOAD_TERMINAL_OK".len())
+                        .any(|w| w == b"DOSH_LOAD_TERMINAL_OK")
+                    {
+                        let _ = seen_tx.send(String::from_utf8_lossy(&output).to_string());
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    thread::sleep(Duration::from_millis(250));
+    writer
+        .write_all(b"printf DOSH_LOAD_TERMINAL_OK\\n\r")
+        .unwrap();
+    writer.flush().unwrap();
+
+    let seen = seen_rx.recv_timeout(Duration::from_secs(3));
+
+    let _ = child.kill();
+    let _ = child.wait();
+    drop(writer);
+    drop(pair.master);
+    let _ = reader_handle.join();
+    let _ = bulk_writer.join();
+    let _ = server.kill();
+    let _ = server.wait();
+
+    assert!(
+        seen.is_ok(),
+        "interactive terminal output was delayed behind local-forward bulk load"
+    );
+}
+
 #[test]
 fn native_remote_forward_echo_smoke() {
     let dir = tempfile::tempdir().unwrap();
@@ -1179,6 +1321,117 @@ fn live_output_forwards_terminal_control_sequences() {
     );
 }
 
+#[test]
+fn tui_control_sequences_survive_transport_verbatim() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    let mut server = start_server(&dir, &config);
+    let (socket, bootstrap, ok) = direct_attach(&config, port, "read-write");
+
+    let sequences = concat!(
+        "\x1b[?1049h", // alternate screen on
+        "\x1b[?2004h", // bracketed paste on
+        "\x1b[?1000h", // mouse tracking on
+        "\x1b[?1006h", // SGR mouse encoding on
+        "\x1b[?25l",   // cursor hidden
+        "\x1b[12;34H", // absolute cursor movement
+        "DOSH_TUI_VERBATIM",
+        "\x1b[?25h",
+        "\x1b[?1006l",
+        "\x1b[?1000l",
+        "\x1b[?2004l",
+        "\x1b[?1049l"
+    );
+    let input = Input {
+        bytes: format!("printf '{sequences}'\n").into_bytes(),
+    };
+    send_encrypted(
+        &socket,
+        port,
+        PacketKind::Input,
+        ok.client_id,
+        2,
+        0,
+        &bootstrap.session_key,
+        &protocol::to_body(&input).unwrap(),
+    );
+    let text = collect_frame_text(&socket, &bootstrap.session_key, 2000);
+
+    let _ = server.kill();
+    let _ = server.wait();
+
+    for needle in [
+        "\x1b[?1049h",
+        "\x1b[?2004h",
+        "\x1b[?1000h",
+        "\x1b[?1006h",
+        "\x1b[?25l",
+        "\x1b[12;34H",
+        "DOSH_TUI_VERBATIM",
+        "\x1b[?25h",
+        "\x1b[?1006l",
+        "\x1b[?1000l",
+        "\x1b[?2004l",
+        "\x1b[?1049l",
+    ] {
+        assert!(
+            text.contains(needle),
+            "expected TUI control sequence {needle:?} to survive verbatim, got {text:?}"
+        );
+    }
+}
+
+#[test]
+fn large_tui_paint_is_delivered_in_mtu_safe_frames() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    let mut server = start_server(&dir, &config);
+    let (socket, bootstrap, ok) = direct_attach(&config, port, "read-write");
+
+    let input = Input {
+        bytes: b"printf '\\033[?1049h'; yes DOSH_TUI_BIG_PAINT | head -n 300 | tr -d '\\n'; printf '\\033[?1049l'\n".to_vec(),
+    };
+    send_encrypted(
+        &socket,
+        port,
+        PacketKind::Input,
+        ok.client_id,
+        2,
+        0,
+        &bootstrap.session_key,
+        &protocol::to_body(&input).unwrap(),
+    );
+
+    let mut text = String::new();
+    let mut saw_split_frame = false;
+    let deadline = std::time::Instant::now() + Duration::from_secs(3);
+    while std::time::Instant::now() < deadline && text.matches("DOSH_TUI_BIG_PAINT").count() < 200 {
+        if let Some((_header, frame)) = recv_frame(&socket, &bootstrap.session_key) {
+            if frame.bytes.len() <= 1400 && frame.bytes.len() >= 900 {
+                saw_split_frame = true;
+            }
+            text.push_str(&String::from_utf8_lossy(&frame.bytes));
+        }
+    }
+
+    let _ = server.kill();
+    let _ = server.wait();
+
+    assert!(
+        text.contains("\x1b[?1049h") && text.matches("DOSH_TUI_BIG_PAINT").count() >= 200,
+        "large alternate-screen paint did not survive transport, enter_alt={} markers={} bytes={}",
+        text.contains("\x1b[?1049h"),
+        text.matches("DOSH_TUI_BIG_PAINT").count(),
+        text.len()
+    );
+    assert!(
+        saw_split_frame,
+        "expected large TUI paint to be split into MTU-safe frames"
+    );
+}
+
 #[test]
 fn resume_snapshot_preserves_alternate_screen_mode() {
     let dir = tempfile::tempdir().unwrap();
@@ -1292,6 +1545,69 @@ fn resume_updates_udp_endpoint_for_roaming() {
     );
 }
 
+#[test]
+#[ignore = "30-minute launch soak; run with `DOSH_SOAK_SECONDS=1800 cargo test --test integration_smoke sleep_roaming_soak_30m -- --ignored --nocapture`"]
+fn sleep_roaming_soak_30m() {
+    let soak_secs = std::env::var("DOSH_SOAK_SECONDS")
+        .ok()
+        .and_then(|value| value.parse::<u64>().ok())
+        .unwrap_or(30 * 60);
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config_with_timeout(&dir, port, soak_secs + 60);
+    let mut server = start_server(&dir, &config);
+    let (_old_socket, bootstrap, ok) = direct_attach(&config, port, "read-write");
+
+    thread::sleep(Duration::from_secs(soak_secs));
+
+    let resumed = UdpSocket::bind("127.0.0.1:0").unwrap();
+    resumed
+        .set_read_timeout(Some(Duration::from_secs(3)))
+        .unwrap();
+    let resume = ResumeRequest {
+        session: "default".to_string(),
+        last_rendered_seq: ok.initial_seq,
+        cols: 80,
+        rows: 24,
+    };
+    send_encrypted(
+        &resumed,
+        port,
+        PacketKind::ResumeRequest,
+        ok.client_id,
+        1,
+        0,
+        &bootstrap.session_key,
+        &protocol::to_body(&resume).unwrap(),
+    );
+    let (_header, resume_frame) =
+        recv_frame(&resumed, &bootstrap.session_key).expect("resume response after soak");
+    assert!(resume_frame.snapshot);
+
+    send_encrypted(
+        &resumed,
+        port,
+        PacketKind::Input,
+        ok.client_id,
+        2,
+        resume_frame.output_seq,
+        &bootstrap.session_key,
+        &protocol::to_body(&Input {
+            bytes: b"printf DOSH_SOAK_OK\\n\n".to_vec(),
+        })
+        .unwrap(),
+    );
+    let text = collect_frame_text(&resumed, &bootstrap.session_key, 3000);
+
+    let _ = server.kill();
+    let _ = server.wait();
+
+    assert!(
+        text.contains("DOSH_SOAK_OK"),
+        "session did not survive {soak_secs}s idle/roaming soak; output={text:?}"
+    );
+}
+
 #[test]
 fn transport_rekey_round_trip_keeps_session_alive() {
     use dosh::native::derive_rekey_session_key;
@@ -1800,3 +2116,316 @@ fn native_agent_forwarding_requires_client_opt_in() {
         "agent proxy dir {agent_dir:?} must not exist without client -A opt-in"
     );
 }
+
+// ---------------------------------------------------------------------------
+// Session persistence across a server restart.
+// ---------------------------------------------------------------------------
+
+/// Write a server config with `persist_sessions = true` so each session's shell
+/// runs in a detached holder that survives a server restart.
+fn write_persistent_server_config(dir: &tempfile::TempDir, port: u16) -> std::path::PathBuf {
+    let config = write_server_config(dir, port);
+    let mut raw = fs::read_to_string(&config).unwrap();
+    // The base writer hardcodes `persist_sessions = false`; flip it on.
+    raw = raw.replace("persist_sessions = false", "persist_sessions = true");
+    fs::write(&config, raw).unwrap();
+    config
+}
+
+/// Mirror the server's hex encoding of a session name to its runtime dir.
+fn session_runtime_dir(sessions_dir: &Path, session: &str) -> PathBuf {
+    let mut hex = String::new();
+    for b in session.as_bytes() {
+        hex.push_str(&format!("{b:02x}"));
+    }
+    sessions_dir.join("run").join(hex)
+}
+
+/// Read a holder's recorded shell pid from its meta file, if present.
+fn holder_shell_pid(sessions_dir: &Path, session: &str) -> Option<i32> {
+    let meta = session_runtime_dir(sessions_dir, session).join("meta");
+    let body = fs::read_to_string(meta).ok()?;
+    body.lines().nth(1)?.parse().ok()
+}
+
+/// Tear down a persistent session's holder + shell so a test never leaks them
+/// (the TempDir drop would otherwise leave detached processes running).
+fn kill_holder(sessions_dir: &Path, session: &str) {
+    if let Some(pid) = holder_shell_pid(sessions_dir, session) {
+        let _ = Command::new("kill").arg("-9").arg(pid.to_string()).status();
+    }
+    // Best-effort: also kill any matching holder process for this runtime dir.
+    let dir = session_runtime_dir(sessions_dir, session);
+    let _ = Command::new("pkill")
+        .arg("-9")
+        .arg("-f")
+        .arg(format!("dosh-server hold --runtime-dir {}", dir.display()))
+        .status();
+}
+
+/// Send one encrypted Input line and give the shell a moment to act.
+fn type_line(socket: &UdpSocket, port: u16, ok: &AttachOk, key: &[u8; 32], seq: u64, line: &str) {
+    let input = Input {
+        bytes: line.as_bytes().to_vec(),
+    };
+    send_encrypted(
+        socket,
+        port,
+        PacketKind::Input,
+        ok.client_id,
+        seq,
+        0,
+        key,
+        &protocol::to_body(&input).unwrap(),
+    );
+    thread::sleep(Duration::from_millis(150));
+}
+
+/// Proof of survival: a session's shell + state + screen outlive a full
+/// `dosh-server` process restart.
+///
+/// We attach, set durable shell state (`cd /tmp`, `export MARK=...`) and paint a
+/// recognizable marker on the screen, wait for the screen to be mirrored to disk,
+/// then KILL the server process (simulating a crash/upgrade). We restart the
+/// server on the same config/sockets, reattach, and assert we land on the SAME
+/// shell — the exported variable and working directory are still there, and the
+/// restored attach snapshot still shows the pre-restart screen — not a fresh
+/// shell.
+#[test]
+fn session_survives_server_restart_same_shell_and_screen() {
+    let dir = tempfile::tempdir().unwrap();
+    let sessions_dir = dir.path().join("sessions");
+    let port = free_udp_port();
+    let config = write_persistent_server_config(&dir, port);
+
+    let mut server = start_server(&dir, &config);
+
+    // First attach: establish durable shell state and a screen marker.
+    let (socket, bootstrap, ok) = direct_attach(&config, port, "read-write");
+    let key = bootstrap.session_key;
+    type_line(&socket, port, &ok, &key, 2, "cd /tmp\n");
+    type_line(
+        &socket,
+        port,
+        &ok,
+        &key,
+        3,
+        "export MARK=zebra_persist_42\n",
+    );
+    // Paint a unique, stable marker into the screen (printf, no trailing newline
+    // scroll surprises) so the restored snapshot is easy to recognize.
+    type_line(
+        &socket,
+        port,
+        &ok,
+        &key,
+        4,
+        "printf 'PRE_RESTART_SCREEN_MARKER\\n'\n",
+    );
+    // Drain output so the parser/screen state and disk mirror catch up.
+    let pre = collect_frame_text(&socket, &key, 1500);
+    assert!(
+        pre.contains("PRE_RESTART_SCREEN_MARKER"),
+        "expected to see the screen marker before restart, got {pre:?}"
+    );
+    // The periodic flush mirrors the screen every ~2s; wait long enough that the
+    // pre-restart screen is guaranteed on disk before we crash the server.
+    thread::sleep(Duration::from_secs(3));
+
+    let shell_pid_before = holder_shell_pid(&sessions_dir, "default");
+    assert!(
+        shell_pid_before.is_some(),
+        "a holder shell pid should be recorded for a persistent session"
+    );
+
+    // CRASH: kill the server process outright (its in-memory state is lost; only
+    // the holder + shell + on-disk screen remain).
+    let _ = server.kill();
+    let _ = server.wait();
+    thread::sleep(Duration::from_millis(300));
+
+    // The holder + shell must still be alive after the server died.
+    let pid = shell_pid_before.unwrap();
+    let alive = unsafe { libc::kill(pid, 0) } == 0;
+    assert!(
+        alive,
+        "shell pid {pid} must survive the server crash (holder keeps it alive)"
+    );
+
+    // RESTART on the same config/sockets; the server re-adopts the holder.
+    let mut server = start_server(&dir, &config);
+
+    // Reattach. A fresh bootstrap attach lands on the EXISTING re-adopted
+    // session (same name), not a new shell.
+    let (socket2, bootstrap2, ok2) = direct_attach(&config, port, "read-write");
+    let key2 = bootstrap2.session_key;
+
+    // 1) Screen survived: the restored attach snapshot still shows the marker.
+    let snapshot = String::from_utf8_lossy(&ok2.snapshot).to_string();
+
+    // 2) Shell identity + state survived: ask the SAME shell for its state.
+    type_line(
+        &socket2,
+        port,
+        &ok2,
+        &key2,
+        2,
+        "printf 'MARK=%s PWD=%s\\n' \"$MARK\" \"$PWD\"\n",
+    );
+    let post = collect_frame_text(&socket2, &key2, 2000);
+
+    let shell_pid_after = holder_shell_pid(&sessions_dir, "default");
+
+    // Clean up BEFORE asserting so a failed assert never leaks the holder.
+    let _ = server.kill();
+    let _ = server.wait();
+    kill_holder(&sessions_dir, "default");
+
+    assert_eq!(
+        shell_pid_after, shell_pid_before,
+        "re-adopted session must be backed by the same shell pid, not a fresh one"
+    );
+    assert!(
+        post.contains("MARK=zebra_persist_42"),
+        "exported variable must survive the restart (same shell), got {post:?}"
+    );
+    assert!(
+        post.contains("PWD=/tmp"),
+        "working directory must survive the restart (same shell), got {post:?}"
+    );
+    assert!(
+        snapshot.contains("PRE_RESTART_SCREEN_MARKER"),
+        "restored attach snapshot must repaint the pre-restart screen, got {snapshot:?}"
+    );
+}
+
+#[test]
+fn multiple_persistent_named_sessions_survive_restart_independently() {
+    let dir = tempfile::tempdir().unwrap();
+    let sessions_dir = dir.path().join("sessions");
+    let port = free_udp_port();
+    let config = write_persistent_server_config(&dir, port);
+
+    let mut server = start_server(&dir, &config);
+
+    let (work_socket, work_bootstrap, work_ok) =
+        direct_attach_session(&config, port, "read-write", "work");
+    let (logs_socket, logs_bootstrap, logs_ok) =
+        direct_attach_session(&config, port, "read-write", "logs");
+    let work_key = work_bootstrap.session_key;
+    let logs_key = logs_bootstrap.session_key;
+
+    type_line(
+        &work_socket,
+        port,
+        &work_ok,
+        &work_key,
+        2,
+        "export DOSH_SLOT=work_slot\n",
+    );
+    type_line(
+        &logs_socket,
+        port,
+        &logs_ok,
+        &logs_key,
+        2,
+        "export DOSH_SLOT=logs_slot\n",
+    );
+    type_line(
+        &work_socket,
+        port,
+        &work_ok,
+        &work_key,
+        3,
+        "printf 'WORK_SCREEN_MARKER\\n'\n",
+    );
+    type_line(
+        &logs_socket,
+        port,
+        &logs_ok,
+        &logs_key,
+        3,
+        "printf 'LOGS_SCREEN_MARKER\\n'\n",
+    );
+    let work_pre = collect_frame_text(&work_socket, &work_key, 1500);
+    let logs_pre = collect_frame_text(&logs_socket, &logs_key, 1500);
+    assert!(
+        work_pre.contains("WORK_SCREEN_MARKER"),
+        "work marker missing before restart: {work_pre:?}"
+    );
+    assert!(
+        logs_pre.contains("LOGS_SCREEN_MARKER"),
+        "logs marker missing before restart: {logs_pre:?}"
+    );
+    thread::sleep(Duration::from_secs(3));
+
+    let work_pid_before = holder_shell_pid(&sessions_dir, "work");
+    let logs_pid_before = holder_shell_pid(&sessions_dir, "logs");
+    assert!(work_pid_before.is_some(), "work holder pid missing");
+    assert!(logs_pid_before.is_some(), "logs holder pid missing");
+    assert_ne!(
+        work_pid_before, logs_pid_before,
+        "named sessions must have independent holder shells"
+    );
+
+    let _ = server.kill();
+    let _ = server.wait();
+    thread::sleep(Duration::from_millis(300));
+
+    let mut server = start_server(&dir, &config);
+    let (work_socket2, work_bootstrap2, work_ok2) =
+        direct_attach_session(&config, port, "read-write", "work");
+    let (logs_socket2, logs_bootstrap2, logs_ok2) =
+        direct_attach_session(&config, port, "read-write", "logs");
+    let work_key2 = work_bootstrap2.session_key;
+    let logs_key2 = logs_bootstrap2.session_key;
+    let work_snapshot = String::from_utf8_lossy(&work_ok2.snapshot).to_string();
+    let logs_snapshot = String::from_utf8_lossy(&logs_ok2.snapshot).to_string();
+
+    type_line(
+        &work_socket2,
+        port,
+        &work_ok2,
+        &work_key2,
+        2,
+        "printf 'WORK_SLOT=%s\\n' \"$DOSH_SLOT\"\n",
+    );
+    type_line(
+        &logs_socket2,
+        port,
+        &logs_ok2,
+        &logs_key2,
+        2,
+        "printf 'LOGS_SLOT=%s\\n' \"$DOSH_SLOT\"\n",
+    );
+    let work_post = collect_frame_text(&work_socket2, &work_key2, 2000);
+    let logs_post = collect_frame_text(&logs_socket2, &logs_key2, 2000);
+    let work_pid_after = holder_shell_pid(&sessions_dir, "work");
+    let logs_pid_after = holder_shell_pid(&sessions_dir, "logs");
+
+    let _ = server.kill();
+    let _ = server.wait();
+    kill_holder(&sessions_dir, "work");
+    kill_holder(&sessions_dir, "logs");
+
+    assert_eq!(work_pid_after, work_pid_before);
+    assert_eq!(logs_pid_after, logs_pid_before);
+    assert!(
+        work_snapshot.contains("WORK_SCREEN_MARKER")
+            && !work_snapshot.contains("LOGS_SCREEN_MARKER"),
+        "work snapshot should restore only work screen, got {work_snapshot:?}"
+    );
+    assert!(
+        logs_snapshot.contains("LOGS_SCREEN_MARKER")
+            && !logs_snapshot.contains("WORK_SCREEN_MARKER"),
+        "logs snapshot should restore only logs screen, got {logs_snapshot:?}"
+    );
+    assert!(
+        work_post.contains("WORK_SLOT=work_slot") && !work_post.contains("logs_slot"),
+        "work state crossed sessions or disappeared: {work_post:?}"
+    );
+    assert!(
+        logs_post.contains("LOGS_SLOT=logs_slot") && !logs_post.contains("work_slot"),
+        "logs state crossed sessions or disappeared: {logs_post:?}"
+    );
+}