sigstore: add function to verify image attestations

__tests__/sigstore/sigstore.test.itg.ts

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-import {describe, expect, jest, it, beforeAll} from '@jest/globals';
+import {beforeAll, describe, expect, jest, it, test} from '@jest/globals';
 import fs from 'fs';
 import * as path from 'path';
 
@@ -23,7 +23,10 @@ import {Sigstore} from '../../src/sigstore/sigstore';
 
 const fixturesDir = path.join(__dirname, '..', '.fixtures');
 
-const maybe = process.env.GITHUB_ACTIONS && process.env.GITHUB_ACTIONS === 'true' && process.env.ACTIONS_ID_TOKEN_REQUEST_URL && process.env.ImageOS && process.env.ImageOS.startsWith('ubuntu') ? describe : describe.skip;
+const runTest = process.env.GITHUB_ACTIONS && process.env.GITHUB_ACTIONS === 'true' && process.env.ImageOS && process.env.ImageOS.startsWith('ubuntu');
+
+const maybe = runTest ? describe : describe.skip;
+const maybeIdToken = runTest && process.env.ACTIONS_ID_TOKEN_REQUEST_URL ? describe : describe.skip;
 
 // needs current GitHub repo info
 jest.unmock('@actions/github');
@@ -36,7 +39,29 @@ beforeAll(async () => {
   await cosignInstall.install(cosignBinPath);
 }, 100000);
 
-maybe('signProvenanceBlobs', () => {
+maybe('verifyImageAttestations', () => {
+  test.each([
+    ['moby/buildkit:master@sha256:84014da3581b2ff2c14cb4f60029cf9caa272b79e58f2e89c651ea6966d7a505', `^https://github.com/docker/github-builder-experimental/.github/workflows/bake.yml.*$`],
+    ['docker/dockerfile-upstream:master@sha256:3e8cd5ebf48acd1a1939649ad1c62ca44c029852b22493c16a9307b654334958', `^https://github.com/docker/github-builder-experimental/.github/workflows/bake.yml.*$`]
+  ])(
+    'given %p',
+    async (image, certificateIdentityRegexp) => {
+      const sigstore = new Sigstore();
+      const verifyResults = await sigstore.verifyImageAttestations(image, {
+        certificateIdentityRegexp: certificateIdentityRegexp
+      });
+      expect(Object.keys(verifyResults).length).toBeGreaterThan(0);
+      for (const [attestationRef, res] of Object.entries(verifyResults)) {
+        expect(attestationRef).toBeDefined();
+        expect(res.cosignArgs).toBeDefined();
+        expect(res.signatureManifestDigest).toBeDefined();
+      }
+    },
+    60000
+  );
+});
+
+maybeIdToken('signProvenanceBlobs', () => {
   it('single platform', async () => {
     const sigstore = new Sigstore();
     const results = await sigstore.signProvenanceBlobs({
@@ -68,20 +93,17 @@ maybe('signProvenanceBlobs', () => {
   });
 });
 
-maybe('verifySignedArtifacts', () => {
+maybeIdToken('verifySignedArtifacts', () => {
   it('sign and verify', async () => {
     const sigstore = new Sigstore();
     const signResults = await sigstore.signProvenanceBlobs({
       localExportDir: path.join(fixturesDir, 'sigstore', 'multi')
     });
     expect(Object.keys(signResults).length).toEqual(2);
 
-    const verifyResults = await sigstore.verifySignedArtifacts(
-      {
-        certificateIdentityRegexp: `^https://github.com/docker/actions-toolkit/.github/workflows/test.yml.*$`
-      },
-      signResults
-    );
+    const verifyResults = await sigstore.verifySignedArtifacts(signResults, {
+      certificateIdentityRegexp: `^https://github.com/docker/actions-toolkit/.github/workflows/test.yml.*$`
+    });
     expect(Object.keys(verifyResults).length).toEqual(2);
     for (const [artifactPath, res] of Object.entries(verifyResults)) {
       expect(fs.existsSync(artifactPath)).toBe(true);

src/cosign/cosign.ts

@@ -142,15 +142,12 @@ export class Cosign {
         bundlePayload = obj as SerializedBundle;
       }
 
-      if (bundlePayload && signatureManifestDigest) {
+      if (bundlePayload && (signatureManifestDigest || signatureManifestFallbackDigest)) {
+        errors = undefined; // clear errors if we have both payload and manifest digest
         break;
       }
     }
 
-    if (!errors && !bundlePayload) {
-      throw new Error(`Cannot find signature bundle from cosign command output: ${logs}`);
-    }
-
     return {
       bundle: bundlePayload,
       signatureManifestDigest: signatureManifestDigest || signatureManifestFallbackDigest,

src/sigstore/sigstore.ts

@@ -80,13 +80,13 @@ export class Sigstore {
           await core.group(`Signing attestation manifest ${attestationRef}`, async () => {
             // prettier-ignore
             const cosignArgs = [
-            'sign',
-            '--yes',
-            '--oidc-provider', 'github-actions',
-            '--registry-referrers-mode', 'oci-1-1',
-            '--new-bundle-format',
-            '--use-signing-config'
-          ];
+              'sign',
+              '--yes',
+              '--oidc-provider', 'github-actions',
+              '--registry-referrers-mode', 'oci-1-1',
+              '--new-bundle-format',
+              '--use-signing-config'
+            ];
             if (noTransparencyLog) {
               cosignArgs.push('--tlog-upload=false');
             }
@@ -106,7 +106,8 @@ export class Sigstore {
                 const errorMessages = signResult.errors.map(e => `- [${e.code}] ${e.message} : ${e.detail}`).join('\n');
                 throw new Error(`Cosign sign command failed with errors:\n${errorMessages}`);
               } else {
-                throw new Error(`Cosign sign command failed with exit code ${execRes.exitCode}`);
+                // prettier-ignore
+                throw new Error(`Cosign sign command failed with: ${execRes.stderr.trim().split(/\r?\n/).filter(line => line.length > 0).pop() ?? 'unknown error'}`);
               }
             }
             const parsedBundle = Sigstore.parseBundle(bundleFromJSON(signResult.bundle));
@@ -127,69 +128,95 @@ export class Sigstore {
     return result;
   }
 
-  public async verifySignedManifests(opts: VerifySignedManifestsOpts, signed: Record<string, SignAttestationManifestsResult>): Promise<Record<string, VerifySignedManifestsResult>> {
+  public async verifySignedManifests(signedManifestsResult: Record<string, SignAttestationManifestsResult>, opts: VerifySignedManifestsOpts): Promise<Record<string, VerifySignedManifestsResult>> {
+    const result: Record<string, VerifySignedManifestsResult> = {};
+    for (const [attestationRef, signedRes] of Object.entries(signedManifestsResult)) {
+      await core.group(`Verifying signature of ${attestationRef}`, async () => {
+        const verifyResult = await this.verifyImageAttestation(attestationRef, {
+          noTransparencyLog: opts.noTransparencyLog || !signedRes.tlogID,
+          certificateIdentityRegexp: opts.certificateIdentityRegexp,
+          retries: opts.retries
+        });
+        core.info(`Signature manifest verified: https://oci.dag.dev/?image=${signedRes.imageName}@${verifyResult.signatureManifestDigest}`);
+        result[attestationRef] = verifyResult;
+      });
+    }
+    return result;
+  }
+
+  public async verifyImageAttestations(image: string, opts: VerifySignedManifestsOpts): Promise<Record<string, VerifySignedManifestsResult>> {
     const result: Record<string, VerifySignedManifestsResult> = {};
+
+    const attestationDigests = await this.imageTools.attestationDigests(image);
+    if (attestationDigests.length === 0) {
+      throw new Error(`No attestation manifests found for ${image}`);
+    }
+
+    const imageName = image.split(':', 1)[0];
+    for (const attestationDigest of attestationDigests) {
+      const attestationRef = `${imageName}@${attestationDigest}`;
+      const verifyResult = await this.verifyImageAttestation(attestationRef, opts);
+      core.info(`Signature manifest verified: https://oci.dag.dev/?image=${imageName}@${verifyResult.signatureManifestDigest}`);
+      result[attestationRef] = verifyResult;
+    }
+
+    return result;
+  }
+
+  public async verifyImageAttestation(attestationRef: string, opts: VerifySignedManifestsOpts): Promise<VerifySignedManifestsResult> {
     const retries = opts.retries ?? 15;
 
     if (!(await this.cosign.isAvailable())) {
       throw new Error('Cosign is required to verify signed manifests');
     }
 
+    // prettier-ignore
+    const cosignArgs = [
+      'verify',
+      '--experimental-oci11',
+      '--new-bundle-format',
+      '--certificate-oidc-issuer', 'https://token.actions.githubusercontent.com',
+      '--certificate-identity-regexp', opts.certificateIdentityRegexp
+    ];
+    if (opts.noTransparencyLog) {
+      // skip tlog verification but still verify the signed timestamp
+      cosignArgs.push('--use-signed-timestamps', '--insecure-ignore-tlog');
+    }
+
     let lastError: Error | undefined;
-    for (const [attestationRef, signedRes] of Object.entries(signed)) {
-      await core.group(`Verifying signature of ${attestationRef}`, async () => {
-        // prettier-ignore
-        const cosignArgs = [
-          'verify',
-          '--experimental-oci11',
-          '--new-bundle-format',
-          '--certificate-oidc-issuer', 'https://token.actions.githubusercontent.com',
-          '--certificate-identity-regexp', opts.certificateIdentityRegexp
-        ];
-        if (!signedRes.tlogID) {
-          // skip tlog verification but still verify the signed timestamp
-          cosignArgs.push('--use-signed-timestamps', '--insecure-ignore-tlog');
-        }
-        core.info(`[command]cosign ${[...cosignArgs, attestationRef].join(' ')}`);
-        for (let attempt = 0; attempt < retries; attempt++) {
-          const execRes = await Exec.getExecOutput('cosign', ['--verbose', ...cosignArgs, attestationRef], {
-            ignoreReturnCode: true,
-            silent: true,
-            env: Object.assign({}, process.env, {
-              COSIGN_EXPERIMENTAL: '1'
-            }) as {[key: string]: string}
-          });
-          const verifyResult = Cosign.parseCommandOutput(execRes.stderr.trim());
-          if (execRes.exitCode === 0) {
-            result[attestationRef] = {
-              cosignArgs: cosignArgs,
-              signatureManifestDigest: verifyResult.signatureManifestDigest!
-            };
-            lastError = undefined;
-            core.info(`Signature manifest verified: https://oci.dag.dev/?image=${signedRes.imageName}@${verifyResult.signatureManifestDigest}`);
-            break;
+    core.info(`[command]cosign ${[...cosignArgs, attestationRef].join(' ')}`);
+    for (let attempt = 0; attempt < retries; attempt++) {
+      const execRes = await Exec.getExecOutput('cosign', ['--verbose', ...cosignArgs, attestationRef], {
+        ignoreReturnCode: true,
+        silent: true,
+        env: Object.assign({}, process.env, {
+          COSIGN_EXPERIMENTAL: '1'
+        }) as {[key: string]: string}
+      });
+      const verifyResult = Cosign.parseCommandOutput(execRes.stderr.trim());
+      if (execRes.exitCode === 0) {
+        return {
+          cosignArgs: cosignArgs,
+          signatureManifestDigest: verifyResult.signatureManifestDigest!
+        };
+      } else {
+        if (verifyResult.errors && verifyResult.errors.length > 0) {
+          const errorMessages = verifyResult.errors.map(e => `- [${e.code}] ${e.message} : ${e.detail}`).join('\n');
+          lastError = new Error(`Cosign verify command failed with errors:\n${errorMessages}`);
+          if (verifyResult.errors.some(e => e.code === 'MANIFEST_UNKNOWN')) {
+            core.info(`Cosign verify command failed with MANIFEST_UNKNOWN, retrying attempt ${attempt + 1}/${retries}...\n${errorMessages}`);
+            await new Promise(res => setTimeout(res, Math.pow(2, attempt) * 100));
           } else {
-            if (verifyResult.errors && verifyResult.errors.length > 0) {
-              const errorMessages = verifyResult.errors.map(e => `- [${e.code}] ${e.message} : ${e.detail}`).join('\n');
-              lastError = new Error(`Cosign verify command failed with errors:\n${errorMessages}`);
-              if (verifyResult.errors.some(e => e.code === 'MANIFEST_UNKNOWN')) {
-                core.info(`Cosign verify command failed with MANIFEST_UNKNOWN, retrying attempt ${attempt + 1}/${retries}...\n${errorMessages}`);
-                await new Promise(res => setTimeout(res, Math.pow(2, attempt) * 100));
-              } else {
-                throw lastError;
-              }
-            } else {
-              throw new Error(`Cosign verify command failed: ${execRes.stderr}`);
-            }
+            throw lastError;
           }
+        } else {
+          // prettier-ignore
+          throw new Error(`Cosign verify command failed with: ${execRes.stderr.trim().split(/\r?\n/).filter(line => line.length > 0).pop() ?? 'unknown error'}`);
         }
-      });
-    }
-    if (lastError) {
-      throw lastError;
+      }
     }
 
-    return result;
+    throw lastError;
   }
 
   public async signProvenanceBlobs(opts: SignProvenanceBlobsOpts): Promise<Record<string, SignProvenanceBlobsResult>> {
@@ -245,12 +272,12 @@ export class Sigstore {
     return result;
   }
 
-  public async verifySignedArtifacts(opts: VerifySignedArtifactsOpts, signed: Record<string, SignProvenanceBlobsResult>): Promise<Record<string, VerifySignedArtifactsResult>> {
+  public async verifySignedArtifacts(signedArtifactsResult: Record<string, SignProvenanceBlobsResult>, opts: VerifySignedArtifactsOpts): Promise<Record<string, VerifySignedArtifactsResult>> {
     const result: Record<string, VerifySignedArtifactsResult> = {};
     if (!(await this.cosign.isAvailable())) {
       throw new Error('Cosign is required to verify signed artifacts');
     }
-    for (const [provenancePath, signedRes] of Object.entries(signed)) {
+    for (const [provenancePath, signedRes] of Object.entries(signedArtifactsResult)) {
       const baseDir = path.dirname(provenancePath);
       await core.group(`Verifying signature bundle ${signedRes.bundlePath}`, async () => {
         for (const subject of signedRes.subjects) {
@@ -263,7 +290,7 @@ export class Sigstore {
             '--certificate-oidc-issuer', 'https://token.actions.githubusercontent.com',
             '--certificate-identity-regexp', opts.certificateIdentityRegexp
           ]
-          if (!signedRes.tlogID) {
+          if (opts.noTransparencyLog || !signedRes.tlogID) {
             // if there is no tlog entry, we skip tlog verification but still verify the signed timestamp
             cosignArgs.push('--use-signed-timestamps', '--insecure-ignore-tlog');
           }

src/types/sigstore/sigstore.ts

@@ -47,6 +47,7 @@ export interface SignAttestationManifestsResult extends ParsedBundle {
 
 export interface VerifySignedManifestsOpts {
   certificateIdentityRegexp: string;
+  noTransparencyLog?: boolean;
   retries?: number;
 }
 
@@ -68,6 +69,7 @@ export interface SignProvenanceBlobsResult extends ParsedBundle {
 
 export interface VerifySignedArtifactsOpts {
   certificateIdentityRegexp: string;
+  noTransparencyLog?: boolean;
 }
 
 export interface VerifySignedArtifactsResult {