sigstore: sign and verify BuildKit attestation manifests

__tests__/.fixtures/cosign/verify-output-err1.txt

@@ -0,0 +1,96 @@
+2025/10/31 13:57:03 --> GET https://index.docker.io/v2/
+2025/10/31 13:57:03 GET /v2/ HTTP/1.1
+Host: index.docker.io
+User-Agent: cosign/v3.0.2 (linux; amd64) go-containerregistry/v0.20.6
+Accept-Encoding: gzip
+
+
+2025/10/31 13:57:03 <-- 401 https://index.docker.io/v2/ (191.948348ms)
+2025/10/31 13:57:03 HTTP/2.0 401 Unauthorized
+Content-Length: 87
+Content-Type: application/json
+Date: Fri, 31 Oct 2025 13:57:03 GMT
+Docker-Distribution-Api-Version: registry/2.0
+Strict-Transport-Security: max-age=31536000
+Www-Authenticate: ***"https://auth.docker.io/token",service="registry.docker.io"
+
+{"errors":[{"code":"UNAUTHORIZED","message":"authentication required","detail":null}]}
+
+2025/10/31 13:57:03 --> GET https://auth.docker.io/token?scope=repository%3Acrazymax%2Fgithub-builder-test%3Apull&service=registry.docker.io [body redacted: basic token response contains credentials]
+2025/10/31 13:57:03 GET /token?scope=repository%3Acrazymax%2Fgithub-builder-test%3Apull&service=registry.docker.io HTTP/1.1
+Host: auth.docker.io
+User-Agent: cosign/v3.0.2 (linux; amd64) go-containerregistry/v0.20.6
+Authorization: <redacted>
+Accept-Encoding: gzip
+
+
+2025/10/31 13:57:03 <-- 200 https://auth.docker.io/token?scope=repository%3Acrazymax%2Fgithub-builder-test%3Apull&service=registry.docker.io (180.01561ms) [body redacted: basic token response contains credentials]
+2025/10/31 13:57:03 HTTP/2.0 200 OK
+Connection: close
+Content-Type: application/json
+Date: Fri, 31 Oct 2025 13:57:03 GMT
+Strict-Transport-Security: max-age=31536000
+X-Trace-Id: 8d63fbce36baf5f2a0c5f2542efa7a7a
+X-Trace-Sampled: false
+
+
+2025/10/31 13:57:03 --> GET https://index.docker.io/v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0
+2025/10/31 13:57:03 GET /v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0 HTTP/1.1
+Host: index.docker.io
+User-Agent: cosign/v3.0.2 (linux; amd64) go-containerregistry/v0.20.6
+Accept: application/vnd.oci.image.index.v1+json
+Authorization: <redacted>
+Accept-Encoding: gzip
+
+
+2025/10/31 13:57:03 <-- 200 https://index.docker.io/v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0 (84.160823ms)
+2025/10/31 13:57:03 HTTP/2.0 200 OK
+Content-Length: 89
+Content-Type: application/vnd.oci.image.index.v1+json
+Date: Fri, 31 Oct 2025 13:57:03 GMT
+Docker-Distribution-Api-Version: registry/2.0
+Strict-Transport-Security: max-age=31536000
+
+{"schemaVersion":2,"mediaType":"application/vnd.oci.image.index.v1+json","manifests":[]}
+
+2025/10/31 13:57:03 --> GET https://index.docker.io/v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0
+2025/10/31 13:57:03 GET /v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0 HTTP/1.1
+Host: index.docker.io
+User-Agent: cosign/v3.0.2 (linux; amd64) go-containerregistry/v0.20.6
+Accept: application/vnd.oci.image.index.v1+json
+Authorization: <redacted>
+Accept-Encoding: gzip
+
+
+2025/10/31 13:57:03 <-- 200 https://index.docker.io/v2/crazymax/github-builder-test/referrers/sha256:6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0 (95.303988ms)
+2025/10/31 13:57:03 HTTP/2.0 200 OK
+Content-Length: 89
+Content-Type: application/vnd.oci.image.index.v1+json
+Date: Fri, 31 Oct 2025 13:57:03 GMT
+Docker-Distribution-Api-Version: registry/2.0
+Strict-Transport-Security: max-age=31536000
+
+{"schemaVersion":2,"mediaType":"application/vnd.oci.image.index.v1+json","manifests":[]}
+
+2025/10/31 13:57:03 --> GET https://index.docker.io/v2/crazymax/github-builder-test/manifests/sha256-6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0.sig
+2025/10/31 13:57:03 GET /v2/crazymax/github-builder-test/manifests/sha256-6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0.sig HTTP/1.1
+Host: index.docker.io
+User-Agent: cosign/v3.0.2 (linux; amd64) go-containerregistry/v0.20.6
+Accept: application/vnd.docker.distribution.manifest.v1+json,application/vnd.docker.distribution.manifest.v1+prettyjws,application/vnd.docker.distribution.manifest.v2+json,application/vnd.oci.image.manifest.v1+json,application/vnd.docker.distribution.manifest.list.v2+json,application/vnd.oci.image.index.v1+json
+Authorization: <redacted>
+Accept-Encoding: gzip
+
+
+2025/10/31 13:57:03 <-- 404 https://index.docker.io/v2/crazymax/github-builder-test/manifests/sha256-6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0.sig (66.155995ms)
+2025/10/31 13:57:03 HTTP/2.0 404 Not Found
+Content-Length: 169
+Content-Type: application/json
+Date: Fri, 31 Oct 2025 13:57:03 GMT
+Docker-Distribution-Api-Version: registry/2.0
+Docker-Ratelimit-Source: d2fd3209-1e2e-451f-b428-29c5bbf3b4b7
+Strict-Transport-Security: max-age=31536000
+
+{"errors":[{"code":"MANIFEST_UNKNOWN","message":"manifest unknown","detail":"unknown tag=sha256-6cc021c733ae2760b2493f449d9885b1606002962b51a9c4f0d0d1568b6dc5c0.sig"}]}
+
+Error: no signatures found
+error during command execution: no signatures found

__tests__/cosign/cosign.test.ts

@@ -15,11 +15,15 @@
  */
 
 import {describe, expect, it, jest, test} from '@jest/globals';
+import fs from 'fs';
+import path from 'path';
 import * as semver from 'semver';
 
 import {Exec} from '../../src/exec';
 import {Cosign} from '../../src/cosign/cosign';
 
+const fixturesDir = path.join(__dirname, '..', '.fixtures');
+
 describe('isAvailable', () => {
   it('checks Cosign is available', async () => {
     const execSpy = jest.spyOn(Exec, 'getExecOutput');
@@ -61,3 +65,26 @@ describe('versionSatisfies', () => {
     expect(await cosign.versionSatisfies(range, version)).toBe(expected);
   });
 });
+
+describe('parseCommandOutput', () => {
+  // prettier-ignore
+  test.each([
+    [path.join(fixturesDir, 'cosign', 'sign-output1.txt')],
+    [path.join(fixturesDir, 'cosign', 'sign-output2.txt')],
+    [path.join(fixturesDir, 'cosign', 'sign-output3.txt')],
+  ])('parsing %p', async (fixturePath: string) => {
+    const signResult = Cosign.parseCommandOutput(fs.readFileSync(fixturePath, 'utf-8'));
+    expect(signResult).toBeDefined();
+    expect(signResult.bundle).toBeDefined();
+  });
+
+  // prettier-ignore
+  test.each([
+    [path.join(fixturesDir, 'cosign', 'verify-output-err1.txt')],
+  ])('parsing %p', async (fixturePath: string) => {
+    const signResult = Cosign.parseCommandOutput(fs.readFileSync(fixturePath, 'utf-8'));
+    expect(signResult).toBeDefined();
+    expect(signResult.bundle).toBeUndefined();
+    expect(signResult.errors).toBeDefined();
+  });
+});

src/cosign/cosign.ts

@@ -15,14 +15,28 @@
  */
 
 import * as core from '@actions/core';
+import {BUNDLE_V03_MEDIA_TYPE, SerializedBundle} from '@sigstore/bundle';
 
 import {Exec} from '../exec';
 import * as semver from 'semver';
+import {MEDIATYPE_EMPTY_JSON_V1} from '../types/oci/mediatype';
 
 export interface CosignOpts {
   binPath?: string;
 }
 
+export interface CosignCommandResult {
+  bundle?: SerializedBundle;
+  signatureManifestDigest?: string;
+  errors?: Array<CosignCommandError>;
+}
+
+export interface CosignCommandError {
+  code: string;
+  message: string;
+  detail: string;
+}
+
 export class Cosign {
   private readonly binPath: string;
   private _version: string;
@@ -88,4 +102,59 @@ export class Cosign {
     core.debug(`Cosign.versionSatisfies ${ver} statisfies ${range}: ${res}`);
     return res;
   }
+
+  public static parseCommandOutput(logs: string): CosignCommandResult {
+    let signatureManifestDigest: string | undefined;
+    let signatureManifestFallbackDigest: string | undefined;
+    let bundlePayload: SerializedBundle | undefined;
+    let errors: Array<CosignCommandError> | undefined;
+
+    for (const rawLine of logs.split(/\r?\n/)) {
+      const line = rawLine.trim();
+      if (!line.startsWith('{') || !line.endsWith('}')) {
+        continue;
+      }
+
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      let obj: any;
+      try {
+        obj = JSON.parse(line);
+      } catch {
+        continue;
+      }
+
+      if (obj && Array.isArray(obj.errors) && obj.errors.length > 0) {
+        errors = obj.errors;
+      }
+
+      // signature manifest digest
+      if (!signatureManifestDigest && obj && Array.isArray(obj.manifests) && obj.manifests.length > 0) {
+        const m0 = obj.manifests[0];
+        if (m0?.artifactType === BUNDLE_V03_MEDIA_TYPE && typeof m0.digest === 'string') {
+          signatureManifestDigest = m0.digest;
+        } else if (m0?.artifactType === MEDIATYPE_EMPTY_JSON_V1 && typeof m0.digest === 'string') {
+          signatureManifestFallbackDigest = m0.digest;
+        }
+      }
+
+      // signature payload
+      if (!bundlePayload && obj && obj.mediaType === BUNDLE_V03_MEDIA_TYPE) {
+        bundlePayload = obj as SerializedBundle;
+      }
+
+      if (bundlePayload && signatureManifestDigest) {
+        break;
+      }
+    }
+
+    if (!errors && !bundlePayload) {
+      throw new Error(`Cannot find signature bundle from cosign command output: ${logs}`);
+    }
+
+    return {
+      bundle: bundlePayload,
+      signatureManifestDigest: signatureManifestDigest || signatureManifestFallbackDigest,
+      errors: errors
+    };
+  }
 }