Harden release artifact verification

scripts/verify-release-artifacts.sh

@@ -22,6 +22,70 @@ artifact_version() {
   esac
 }
 
+archive_contains() {
+  artifact="$1"
+  member="$2"
+  case "$artifact" in
+    *.tar.gz)
+      tar -tzf "$artifact" "$member" >/dev/null 2>&1
+      ;;
+    *.zip)
+      unzip -Z1 "$artifact" 2>/dev/null | grep -Fx "$member" >/dev/null 2>&1
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+expected_members() {
+  artifact_name="$(basename -- "$1")"
+  case "$artifact_name" in
+    dosh-windows-*.zip)
+      cat <<EOF
+dosh/VERSION
+dosh/bin/dosh.exe
+dosh/bin/dosh-client.exe
+dosh/bin/dosh-bench.exe
+EOF
+      ;;
+    dosh-*.tar.gz)
+      cat <<EOF
+dosh/VERSION
+dosh/bin/dosh
+dosh/bin/dosh-client
+dosh/bin/dosh-server
+dosh/bin/dosh-auth
+dosh/bin/dosh-bench
+EOF
+      ;;
+    *)
+      cat <<EOF
+dosh/VERSION
+EOF
+      ;;
+  esac
+}
+
+checksum_value() {
+  artifact="$1"
+  if command -v sha256sum >/dev/null 2>&1; then
+    sha256sum "$artifact" | awk '{print $1}'
+  elif command -v shasum >/dev/null 2>&1; then
+    shasum -a 256 "$artifact" | awk '{print $1}'
+  else
+    return 1
+  fi
+}
+
+verify_checksum() {
+  artifact="$1"
+  checksum="$artifact.sha256"
+  expected="$(awk '{print $1; exit}' "$checksum")"
+  actual="$(checksum_value "$artifact" || true)"
+  [ -n "$actual" ] && [ "$actual" = "$expected" ]
+}
+
 if [ "$#" -gt 0 ]; then
   artifacts="$*"
 else
@@ -38,12 +102,21 @@ for artifact in $artifacts; do
   if [ ! -f "$artifact.sha256" ]; then
     echo "missing release checksum: $artifact.sha256" >&2
     failed=1
+  elif ! verify_checksum "$artifact"; then
+    echo "release checksum mismatch: $artifact" >&2
+    failed=1
   fi
   actual="$(artifact_version "$artifact" || true)"
   if [ "$actual" != "$version" ]; then
     echo "artifact version mismatch: $artifact has ${actual:-unknown}, expected $version" >&2
     failed=1
   fi
+  for member in $(expected_members "$artifact"); do
+    if ! archive_contains "$artifact" "$member"; then
+      echo "artifact missing expected member: $artifact:$member" >&2
+      failed=1
+    fi
+  done
 done
 
 exit "$failed"