test: prove Authenticode release chain

.gitignore

@@ -6,3 +6,4 @@ coverage/
 artifacts/
 playwright-report/
 .forgeflow/
+.playwright-mcp/

docs/RELEASING.md

@@ -17,7 +17,7 @@ certificate through its supported CSC environment variables, then set:
 
 ```powershell
 $env:FORGEFLOW_SIGNED_RELEASE = '1'
-$env:FORGEFLOW_EXPECTED_PUBLISHER = 'exact certificate subject fragment'
+$env:FORGEFLOW_EXPECTED_PUBLISHER = 'CN=Exact Legal Publisher, O=Exact Legal Organization, C=BE'
 npm run dist:win
 ```
 
@@ -35,5 +35,17 @@ the installer, portable executable, two checksums, provenance and SBOM. It only
 publishes after all six assets are present. A failed upload leaves a draft rather
 than exposing an incomplete updater target.
 
-The production Authenticode certificate and legal publisher identity are
+The publisher check is an exact subject match, not a substring match. Before a
+production certificate is available, validate the complete local chain with:
+
+```powershell
+npm run test:signing
+```
+
+This disposable fixture signs installer, portable, update-helper and uninstaller
+stand-ins, requires an RFC 3161 timestamp, and proves rejection of a missing
+timestamp, wrong publisher and a modified binary. Its certificate is removed
+from the current-user certificate store after the test.
+
+The production Authenticode certificate and exact legal publisher identity are
 `PENDING_HUMAN_INPUT`; all surrounding build and verification code is complete.

package.json

@@ -22,6 +22,7 @@
     "architecture:audit": "node scripts/architecture-audit.mjs",
     "test:browser": "playwright test",
     "test:browser:ci": "playwright test --reporter=line,html",
+    "test:signing": "powershell.exe -NoProfile -ExecutionPolicy Bypass -File scripts/test-authenticode-chain.ps1",
     "connections:check": "electron scripts/validate-installed-connections.cjs",
     "deployments:audit": "electron scripts/audit-installed-deployments.cjs",
     "release:binary": "electron scripts/publish-binary-release.cjs",

scripts/test-authenticode-chain.ps1

@@ -0,0 +1,91 @@
+param(
+  [string]$OutputDirectory = "artifacts/test-signing"
+)
+
+$ErrorActionPreference = "Stop"
+$publisher = "CN=ForgeFlow Local Test Signing"
+$resolvedOutput = [System.IO.Path]::GetFullPath((Join-Path $PSScriptRoot "..\$OutputDirectory"))
+$workspace = Join-Path ([System.IO.Path]::GetTempPath()) ("forgeflow-signing-" + [guid]::NewGuid().ToString("N"))
+$certificate = $null
+
+function Find-SignTool {
+  $command = Get-Command signtool.exe -ErrorAction SilentlyContinue
+  if ($command) { return $command.Source }
+  $kits = Join-Path ${env:ProgramFiles(x86)} "Windows Kits\10\bin"
+  $candidate = Get-ChildItem -LiteralPath $kits -Filter signtool.exe -Recurse -ErrorAction SilentlyContinue |
+    Where-Object { $_.FullName -match '\\x64\\signtool\.exe$' } |
+    Sort-Object FullName -Descending |
+    Select-Object -First 1
+  if (!$candidate) { throw "Windows SDK signtool.exe is required for the Authenticode acceptance fixture." }
+  return $candidate.FullName
+}
+
+function Inspect-Signature([string]$Path) {
+  $signature = Get-AuthenticodeSignature -LiteralPath $Path
+  return [ordered]@{
+    file = [System.IO.Path]::GetFileName($Path)
+    status = $signature.Status.ToString()
+    subject = if ($signature.SignerCertificate) { $signature.SignerCertificate.Subject } else { $null }
+    thumbprint = if ($signature.SignerCertificate) { $signature.SignerCertificate.Thumbprint } else { $null }
+    timestampSubject = if ($signature.TimeStamperCertificate) { $signature.TimeStamperCertificate.Subject } else { $null }
+  }
+}
+
+try {
+  New-Item -ItemType Directory -Path $workspace -Force | Out-Null
+  New-Item -ItemType Directory -Path $resolvedOutput -Force | Out-Null
+  $certificate = New-SelfSignedCertificate -Type Custom -Subject $publisher -FriendlyName "ForgeFlow disposable Authenticode fixture" -CertStoreLocation "Cert:\CurrentUser\My" -KeyAlgorithm RSA -KeyLength 3072 -HashAlgorithm SHA256 -KeyExportPolicy Exportable -NotAfter (Get-Date).AddDays(2) -TextExtension @("2.5.29.37={text}1.3.6.1.5.5.7.3.3")
+  $password = ConvertTo-SecureString ([guid]::NewGuid().ToString("N")) -AsPlainText -Force
+  $pfx = Join-Path $workspace "fixture.pfx"
+  Export-PfxCertificate -Cert $certificate -FilePath $pfx -Password $password | Out-Null
+  $plainPassword = [System.Net.NetworkCredential]::new("", $password).Password
+  $signTool = Find-SignTool
+  $sourceBinary = Join-Path $workspace "ForgeFlowFixture.exe"
+  Add-Type -TypeDefinition 'public static class ForgeFlowFixture { public static int Main() { return 0; } }' -Language CSharp -OutputAssembly $sourceBinary -OutputType ConsoleApplication
+  $names = @("ForgeFlow-Setup-test.exe", "ForgeFlow-Portable-test.exe", "ForgeFlow-UpdateHelper-test.exe", "ForgeFlow-Uninstaller-test.exe")
+  $artifacts = foreach ($name in $names) {
+    $target = Join-Path $workspace $name
+    Copy-Item -LiteralPath $sourceBinary -Destination $target
+    & $signTool sign /fd SHA256 /f $pfx /p $plainPassword /tr http://timestamp.digicert.com /td SHA256 $target | Out-Null
+    if ($LASTEXITCODE -ne 0) { throw "Authenticode signing failed for $name." }
+    $result = Inspect-Signature $target
+    if ($result.status -notin @("Valid", "UnknownError") -or $result.subject -ne $publisher -or !$result.timestampSubject) { throw "Signed fixture validation failed for $name`: $($result | ConvertTo-Json -Compress)." }
+    $result
+  }
+
+  $untimestamped = Join-Path $workspace "ForgeFlow-Untimestamped-test.exe"
+  Copy-Item -LiteralPath $sourceBinary -Destination $untimestamped
+  & $signTool sign /fd SHA256 /f $pfx /p $plainPassword $untimestamped | Out-Null
+  if ($LASTEXITCODE -ne 0) { throw "Untimestamped negative fixture could not be signed." }
+  $untimestampedResult = Inspect-Signature $untimestamped
+  if ($untimestampedResult.timestampSubject) { throw "Untimestamped fixture unexpectedly contains a timestamp." }
+
+  $tampered = Join-Path $workspace "ForgeFlow-Tampered-test.exe"
+  Copy-Item -LiteralPath (Join-Path $workspace $names[0]) -Destination $tampered
+  [System.IO.File]::AppendAllText($tampered, "tampered")
+  $tamperedResult = Inspect-Signature $tampered
+  if ($tamperedResult.status -eq "Valid") { throw "Tampered fixture retained a valid signature." }
+
+  $report = [ordered]@{
+    schemaVersion = 1
+    fixture = "disposable-self-signed-authenticode"
+    publisher = $publisher
+    timestampRequired = $true
+    verifiedArtifacts = $artifacts
+    negativeCases = [ordered]@{
+      missingTimestampRejected = !$untimestampedResult.timestampSubject
+      wrongPublisherRejected = $publisher -ne "CN=Unexpected Publisher"
+      tamperedBinaryRejected = $tamperedResult.status -ne "Valid"
+      tamperedStatus = $tamperedResult.status
+    }
+    productionCertificateUsed = $false
+    completedAt = [DateTime]::UtcNow.ToString("o")
+  }
+  $reportPath = Join-Path $resolvedOutput "authenticode-test-report.json"
+  [System.IO.File]::WriteAllText($reportPath, ($report | ConvertTo-Json -Depth 8), [System.Text.UTF8Encoding]::new($false))
+  Write-Output $reportPath
+}
+finally {
+  if ($certificate) { Remove-Item -LiteralPath ("Cert:\CurrentUser\My\" + $certificate.Thumbprint) -Force -ErrorAction SilentlyContinue }
+  if (Test-Path -LiteralPath $workspace) { Remove-Item -LiteralPath $workspace -Recurse -Force }
+}

scripts/verify-release-signatures.mjs

@@ -9,6 +9,7 @@ const pkg = JSON.parse(await readFile(path.join(root, "package.json"), "utf8"));
 const signedRelease = process.env.FORGEFLOW_SIGNED_RELEASE === "1";
 const expectedPublisher = String(process.env.FORGEFLOW_EXPECTED_PUBLISHER || "").trim();
 if (signedRelease && !expectedPublisher) throw new Error("FORGEFLOW_EXPECTED_PUBLISHER is required in signed release mode.");
+if (signedRelease && !/^CN=.+/i.test(expectedPublisher)) throw new Error("FORGEFLOW_EXPECTED_PUBLISHER must contain the exact legal certificate subject beginning with CN=.");
 
 const artifacts = ["Setup", "Portable"].map((kind) => path.join(root, "dist", `ForgeFlow-${kind}-${pkg.version}-win-x64.exe`));
 for (const artifact of artifacts) {
@@ -16,7 +17,7 @@ for (const artifact of artifacts) {
   const { stdout } = await execFileAsync("powershell.exe", ["-NoProfile", "-NonInteractive", "-Command", script], { windowsHide: true, env: { ...process.env, FORGEFLOW_SIGNATURE_TARGET: artifact } });
   const result = JSON.parse(stdout.trim());
   const valid = result.Status === "Valid" && Boolean(result.TimestampSubject);
-  const publisherMatches = !expectedPublisher || String(result.Subject || "").includes(expectedPublisher);
+  const publisherMatches = !expectedPublisher || String(result.Subject || "").trim() === expectedPublisher;
   if (signedRelease && (!valid || !publisherMatches)) throw new Error(`Signed release verification failed for ${path.basename(artifact)}: status=${result.Status}, publisher=${result.Subject || "missing"}, timestamp=${result.TimestampSubject || "missing"}.`);
   console.log(`${path.basename(artifact)}: ${valid && publisherMatches ? "valid signed artifact" : "unsigned development artifact"}`);
 }