ci: pin every third-party action to a commit SHA, gated and Dependabot-maintained (D-226)

A tag is a mutable pointer owned by the action's publisher. These jobs are not
ordinary CI: they hold the code-signing Key Vault token (D-223), the federated
storage credentials (D-222), and combine-rules.yml holds a contents:write token
that pushes to main. Whoever could repoint v7 would run code with all of that.

azure/login and Azure/functions-action were already pinned; the actions/* and
github/codeql-action references were not, on the usual argument that GitHub owns
them and shares the runner's trust boundary. That argument does not survive the
fact that they run in the same jobs as the signing identity. All seven are now
pinned by SHA with the version in a trailing comment -- the comment is what keeps
the line reviewable, and Dependabot rewrites both together.

action-pins.yml is the guard: pins nobody enforces rot, and no review reliably
catches one @v4 added to a 200-line workflow. It lives in its own workflow because
ci.yml deliberately ignores changes to the other workflow files, so a job placed
there would stay silent for exactly the commits it must inspect. Like CI it reports
rather than blocks -- main is unprotected; making it binding would mean adding it
as a required status check, which is a branch-protection decision.

Verified both directions: 49 references pass against the repo, and a fixture with
@v7, @main and a bare SHA fails with three annotations while the local reusable
workflow refs are skipped.

Two floating tool versions closed while here. wix went from the range 5.* to 5.0.2
-- it writes the bytes of the MSI customers install, where AzureSignTool only signs
them. ajv was the worse one: unpinned, and npm runs lifecycle scripts at install,
so a hijacked release would have executed with the push token before a single rule
was validated; now exact versions with --ignore-scripts.

Line endings: sed -i rewrote the workflow files as LF. Git normalises on commit, so
the content diff is unaffected and indexnow-notify.yml carries no change at all.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.github/dependabot.yml

@@ -55,6 +55,10 @@ updates:
       - dependency-name: '*'
         update-types: ['version-update:semver-major']
 
+  # Every action is referenced by commit SHA with the version in a trailing comment;
+  # action-pins.yml fails any workflow change that reintroduces a mutable tag. Dependabot
+  # is what keeps those pins current: it rewrites the SHA and the comment together, so the
+  # pins are reviewed in a PR instead of drifting silently or being bumped by hand.
   - package-ecosystem: github-actions
     directory: /
     schedule:

.github/workflows/action-pins.yml

@@ -0,0 +1,70 @@
+name: Action Pin Gate
+
+# Every third-party action must be referenced by a full commit SHA, never by a tag.
+# Tags are mutable: whoever controls an action repository can repoint v4 at new code,
+# and that code runs inside jobs that hold the code-signing identity, the storage
+# credentials and a token that can push to main. A SHA is the only reference an
+# upstream owner cannot change under us.
+#
+# Lives in its own workflow rather than in ci.yml: CI deliberately ignores changes to
+# the other workflow files, so a guard placed there would stay silent for exactly the
+# commits it needs to inspect.
+#
+# Like CI, this reports rather than blocks: main is deliberately unprotected, so a red
+# run is a signal to act on, not a merge barrier. Making it binding means adding
+# 'Verify action pins' as a required status check -- a branch-protection decision, not
+# something this file can assert.
+#
+# The pins are not maintained by hand — .github/dependabot.yml opens a monthly grouped
+# PR that rewrites both the SHA and the trailing version comment. The comment is
+# therefore required too: it is what makes a pinned line reviewable.
+
+on:
+  push:
+    branches: [main]
+    paths: ['.github/workflows/**']
+  pull_request:
+    branches: [main]
+    paths: ['.github/workflows/**']
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  verify-pins:
+    name: Verify action pins
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
+
+      - name: Every third-party action is pinned to a SHA
+        run: |
+          set -uo pipefail
+          failed=0
+          while IFS=: read -r file line ref; do
+            # Reusable workflows from this repository move with the commit that calls
+            # them, so there is nothing to pin.
+            case "$ref" in ./*) continue ;; esac
+
+            if [[ "$ref" =~ ^[^@]+@[0-9a-f]{40}[[:space:]]+#[[:space:]]*[^[:space:]] ]]; then
+              printf 'ok  %s:%s  %s\n' "$file" "$line" "$ref"
+              continue
+            fi
+
+            if [[ "$ref" =~ ^[^@]+@[0-9a-f]{40}[[:space:]]*$ ]]; then
+              echo "::error file=$file,line=$line::Pinned but the version comment is missing: '$ref'. Write 'owner/action@<sha> # vN' so the line stays reviewable."
+            else
+              echo "::error file=$file,line=$line::Action '$ref' is not pinned to a commit SHA. Tags are mutable -- resolve it with: gh api repos/<owner>/<action>/git/ref/tags/<tag>"
+            fi
+            failed=1
+          # -H is load-bearing: with a single matching file grep omits the name, the
+          # fields shift by one and every diagnostic points at nothing.
+          done < <(grep -nHE '^[[:space:]]*(-[[:space:]]+)?uses:' .github/workflows/*.yml \
+                   | sed -E 's/^([^:]+):([0-9]+):[[:space:]]*(-[[:space:]]+)?uses:[[:space:]]*/\1:\2:/')
+
+          if [ "$failed" -ne 0 ]; then
+            echo "::error::Unpinned action references found -- fix them before this reaches main."
+            exit 1
+          fi
+          echo "All action references are pinned to commit SHAs."

.github/workflows/bootstrap-script-gates.yml

@@ -18,7 +18,7 @@ jobs:
     name: Bootstrap guard tests (PS 5.1)
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       - name: Install Pester 5+
         shell: powershell

.github/workflows/build-agent.yml

@@ -72,7 +72,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       # Every released build is signed; a missing variable stops the run before a build
       # number is burnt.
@@ -122,7 +122,7 @@ jobs:
 
       # SDK 10 = single build toolchain (parity with local build.ps1 / global.json).
       - name: Setup .NET
-        uses: actions/setup-dotnet@v6
+        uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6
         with:
           dotnet-version: '10.0.x'
 
@@ -462,7 +462,7 @@ jobs:
       # Skipped on runs that publish nothing -- no log entry for bytes nobody receives.
       - name: Attest build provenance
         if: inputs.upload_blob || inputs.create_release
-        uses: actions/attest-build-provenance@v4
+        uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4
         with:
           subject-path: |
             ${{ steps.artifact.outputs.versioned_zip_release }}
@@ -470,13 +470,13 @@ jobs:
             staging/agent/AutopilotMonitor.SummaryDialog.exe
 
       - name: Upload build artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: AutopilotMonitor-Agent-v${{ steps.version.outputs.version }}
           path: ${{ steps.artifact.outputs.versioned_zip_release }}
 
       - name: Upload version metadata
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: version-metadata
           path: ${{ env.MANIFEST_NAME }}

.github/workflows/build-msi.yml

@@ -40,7 +40,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       # The loader executes as SYSTEM on every enrolling device — a parse error or
       # non-ASCII mojibake (PS 5.1 codepage roulette) must fail the build, not the fleet.
@@ -111,8 +111,11 @@ jobs:
           tenant-id: ${{ secrets.AZURE_TENANT_ID }}
           subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
 
+      # Exact version, not a "5.*" range: wix writes the bytes of the MSI that customers
+      # install, so a compromised or simply broken point release must not flow into a build
+      # unnoticed. Bumping is a reviewed commit.
       - name: Install WiX toolset
-        run: dotnet tool install --global wix --version "5.*"
+        run: dotnet tool install --global wix --version 5.0.2
 
       # Version pinned; roll-forward because the tool targets an older runtime than the SDK.
       - name: Install AzureSignTool
@@ -235,12 +238,12 @@ jobs:
       # gh attestation verify AutopilotMonitor-Bootstrap.msi --repo okieselbach/AutopilotMonitor
       - name: Attest build provenance (MSI)
         if: inputs.upload_blob
-        uses: actions/attest-build-provenance@v4
+        uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4
         with:
           subject-path: ${{ env.STABLE_MSI }}
 
       - name: Upload build artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: AutopilotMonitor-Bootstrap-v${{ steps.version.outputs.version }}
           path: ${{ env.STABLE_MSI }}

.github/workflows/ci.yml

@@ -35,6 +35,7 @@ on:
       # Every other workflow: nothing here builds or tests anything CI covers. paths-ignore
       # cannot negate, so they are listed one by one; ci.yml itself stays out of the list
       # so a change to CI runs CI. A new workflow file is opt-in — add it here too.
+      - '.github/workflows/action-pins.yml'
       - '.github/workflows/bootstrap-script-gates.yml'
       - '.github/workflows/build-agent.yml'
       - '.github/workflows/build-msi.yml'
@@ -67,6 +68,7 @@ on:
       # Every other workflow: nothing here builds or tests anything CI covers. paths-ignore
       # cannot negate, so they are listed one by one; ci.yml itself stays out of the list
       # so a change to CI runs CI. A new workflow file is opt-in — add it here too.
+      - '.github/workflows/action-pins.yml'
       - '.github/workflows/bootstrap-script-gates.yml'
       - '.github/workflows/build-agent.yml'
       - '.github/workflows/build-msi.yml'
@@ -94,9 +96,9 @@ jobs:
     # windows-latest is required: the agent test projects target net48.
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-dotnet@v6
+      - uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6
         with:
           dotnet-version: '10.0.x'
 
@@ -125,9 +127,9 @@ jobs:
       run:
         working-directory: src/Web/autopilot-monitor-web
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
           cache: npm
@@ -159,9 +161,9 @@ jobs:
       run:
         working-directory: src/McpServer/autopilot-monitor-mcp
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
           cache: npm
@@ -179,7 +181,7 @@ jobs:
       # (run 31252869254). Persist the model across runs instead; HF_CACHE_DIR
       # is honored by vector-search-provider.ts.
       - name: Cache embedding model
-        uses: actions/cache@v6
+        uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6
         with:
           path: ${{ github.workspace }}/.hf-cache
           key: hf-model-Xenova-all-MiniLM-L6-v2
@@ -193,9 +195,9 @@ jobs:
     name: Generated guardrails match rules/guardrails.json
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
 
@@ -214,9 +216,9 @@ jobs:
     name: Generated wire types match shared-manifests.json
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
 

.github/workflows/codeql.yml

@@ -102,15 +102,15 @@ jobs:
             build-mode: none
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-dotnet@v6
+      - uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6
         if: matrix.language == 'csharp'
         with:
           dotnet-version: '10.0.x'
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.37.9
+        uses: github/codeql-action/init@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
@@ -121,6 +121,6 @@ jobs:
         run: dotnet build AutopilotMonitor.sln --configuration Release
 
       - name: Analyze
-        uses: github/codeql-action/analyze@v4.37.9
+        uses: github/codeql-action/analyze@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
         with:
           category: /language:${{ matrix.language }}

.github/workflows/combine-rules.yml

@@ -24,14 +24,17 @@ jobs:
     permissions:
       contents: write
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
 
+      # Exact versions and no lifecycle scripts: this job holds contents:write and pushes to
+      # main, so an install-time script from a hijacked package would run with a token that
+      # can rewrite the repository. ajv is pure JS and needs no install hooks.
       - name: Install ajv-cli
-        run: npm install -g ajv-cli ajv-formats
+        run: npm install -g --ignore-scripts ajv-cli@5.0.0 ajv-formats@3.0.1
 
       - name: Validate Gather Rules
         run: |

.github/workflows/deploy-backend.yml

@@ -19,7 +19,7 @@ jobs:
     name: Build and Deploy Backend
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       - name: Login to Azure (OIDC)
         uses: azure/login@7ddb5af1ef8758cf1353cf3b42f940aee27ba21c # v3
@@ -29,7 +29,7 @@ jobs:
           subscription-id: ${{ secrets.AZURE_SUBSCRIPTION_ID }}
 
       - name: Setup .NET 10
-        uses: actions/setup-dotnet@v6
+        uses: actions/setup-dotnet@a98b56852c35b8e3190ac28c8c2271da59106c68 # v6
         with:
           dotnet-version: '10.0.x'
 

.github/workflows/deploy-mcp.yml

@@ -26,7 +26,7 @@ jobs:
     name: Build and Deploy MCP Server
 
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       # The published customer documentation lives in its own PUBLIC repo and is
       # baked into the image as the search_docs corpus (see the Dockerfile). No
@@ -36,7 +36,7 @@ jobs:
       # re-run actually rolls a new revision). /health reports the SHA captured
       # below so that staleness is checkable.
       - name: Check out documentation bundle
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
           repository: autopilotmonitor/autopilotmonitor-docs
           path: mcp-docs

.github/workflows/deploy-web.yml

@@ -35,7 +35,7 @@ jobs:
     runs-on: ubuntu-latest
     name: Build and Deploy Job
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
           lfs: false
           fetch-depth: 0  # Full history needed for git-based sitemap lastmod dates
@@ -56,7 +56,7 @@ jobs:
       # workflow runs again (push under src/Web/** or a manual dispatch); versions/web.json
       # records which docs commit is live.
       - name: Check out documentation bundle
-        uses: actions/checkout@v7
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
         with:
           repository: autopilotmonitor/autopilotmonitor-docs
           path: whats-new-docs
@@ -66,7 +66,7 @@ jobs:
         id: docs
         run: echo "sha=$(git -C whats-new-docs rev-parse HEAD)" >> "$GITHUB_OUTPUT"
 
-      - uses: actions/setup-node@v7
+      - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7
         with:
           node-version: '22'
           cache: npm
@@ -114,12 +114,12 @@ jobs:
       # commit, workflow file) in a public transparency log.
       # Verify: gh attestation verify portal-<sha>.tar.gz --repo okieselbach/AutopilotMonitor
       - name: Attest build provenance (portal export)
-        uses: actions/attest-build-provenance@v4
+        uses: actions/attest-build-provenance@4d101475d8b20a2381f78447822ac1eab6504dd8 # v4
         with:
           subject-path: ${{ steps.package.outputs.archive }}
 
       - name: Upload build artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: portal-${{ github.sha }}
           path: ${{ steps.package.outputs.archive }}

.github/workflows/publish-scripts.yml

@@ -54,7 +54,7 @@ jobs:
     needs: gates
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
 
       - name: Check code-signing configuration
         shell: pwsh
@@ -127,7 +127,7 @@ jobs:
       # when someone wants to look at the file.
       - name: Upload signed scripts
         if: always()
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: signed-scripts
           path: ${{ runner.temp }}/signed-scripts