Add Microsoft signature verification support

gdams · Jun 29, 2026 · Jun 17, 2026 · Jun 17, 2026 · Jun 17, 2026 · Jun 17, 2026
commit db1f1b87544f03c66ad108ff152c3e03c87c9c0a
@@ -48,7 +48,7 @@ For information about the latest releases, recent updates, and newly supported d
 
   - `check-latest`: Setting this option makes the action to check for the latest available version for the version spec.
 
-  - `verify-signature`: Verifies downloaded Java package signatures when supported by the selected distribution. Currently supported for `temurin`. If set to `true` for unsupported distributions, the action fails.
+  - `verify-signature`: Verifies downloaded Java package signatures when supported by the selected distribution. Currently supported for `temurin` and `microsoft`. If set to `true` for unsupported distributions, the action fails.
 
   - `cache`: Quick [setup caching](#caching-packages-dependencies) for the dependencies managed through one of the predefined package managers. It can be one of "maven", "gradle" or "sbt".
 

@@ -1,8 +1,15 @@
-import {MicrosoftDistributions} from '../../src/distributions/microsoft/installer';
+import {
+  MicrosoftDistributions,
+  MICROSOFT_PUBLIC_KEY
+} from '../../src/distributions/microsoft/installer';
 import os from 'os';
 import data from '../data/microsoft.json';
 import * as httpm from '@actions/http-client';
 import * as core from '@actions/core';
+import * as tc from '@actions/tool-cache';
+import * as gpg from '../../src/gpg';
+import * as util from '../../src/util';
+import fs from 'fs';
 
 describe('findPackageForDownload', () => {
   let distribution: MicrosoftDistributions;
@@ -97,6 +104,7 @@ describe('findPackageForDownload', () => {
       .replace('{{OS_TYPE}}', os)
       .replace('{{ARCHIVE_TYPE}}', archive);
     expect(result.url).toBe(url);
+    expect(result.signatureUrl).toBe(`${url}.sig`);
   });
 
   it.each([
@@ -183,3 +191,118 @@ describe('findPackageForDownload', () => {
     );
   });
 });
+
+describe('downloadTool', () => {
+  let spyDownloadTool: jest.SpyInstance;
+  let spyExtractJdkFile: jest.SpyInstance;
+  let spyCacheDir: jest.SpyInstance;
+  let spyVerifySignature: jest.SpyInstance;
+  let distribution: MicrosoftDistributions;
+
+  beforeEach(() => {
+    jest
+      .spyOn(os, 'platform')
+      .mockReturnValue(process.platform as ReturnType<typeof os.platform>);
+
+    distribution = new MicrosoftDistributions({
+      version: '17',
+      architecture: 'x64',
+      packageType: 'jdk',
+      checkLatest: false
+    });
+
+    spyDownloadTool = jest.spyOn(tc, 'downloadTool');
+    spyDownloadTool.mockImplementation(async () => {
+      return '/tmp/jdk.tar.gz';
+    });
+
+    spyExtractJdkFile = jest.spyOn(util, 'extractJdkFile');
+    spyExtractJdkFile.mockImplementation(async () => {
+      return '/tmp/unpacked';
+    });
+
+    jest.spyOn(fs, 'readdirSync').mockReturnValue(['jdk'] as any);
+    spyCacheDir = jest.spyOn(tc, 'cacheDir');
+    spyCacheDir.mockImplementation(async () => {
+      return '/tmp/cached';
+    });
+
+    spyVerifySignature = jest.spyOn(gpg, 'verifyPackageSignature');
+    spyVerifySignature.mockImplementation(async () => {});
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  it('verifies signature when enabled', async () => {
+    const signedDistribution = new MicrosoftDistributions({
+      version: '17',
+      architecture: 'x64',
+      packageType: 'jdk',
+      checkLatest: false,
+      verifySignature: true
+    });
+
+    await signedDistribution['downloadTool']({
+      version: '17.0.14+7',
+      url: 'https://example.com/jdk.tar.gz',
+      signatureUrl: 'https://example.com/jdk.tar.gz.sig'
+    });
+
+    expect(spyVerifySignature).toHaveBeenCalledWith(
+      '/tmp/jdk.tar.gz',
+      'https://example.com/jdk.tar.gz.sig',
+      MICROSOFT_PUBLIC_KEY
+    );
+  });
+
+  it('uses custom public key when verifySignaturePublicKey is provided', async () => {
+    const customKey =
+      '-----BEGIN PGP PUBLIC KEY BLOCK-----\ncustom\n-----END PGP PUBLIC KEY BLOCK-----';
+    const signedDistribution = new MicrosoftDistributions({
+      version: '17',
+      architecture: 'x64',
+      packageType: 'jdk',
+      checkLatest: false,
+      verifySignature: true,
+      verifySignaturePublicKey: customKey
+    });
+
+    await signedDistribution['downloadTool']({
+      version: '17.0.14+7',
+      url: 'https://example.com/jdk.tar.gz',
+      signatureUrl: 'https://example.com/jdk.tar.gz.sig'
+    });
+
+    expect(spyVerifySignature).toHaveBeenCalledWith(
+      '/tmp/jdk.tar.gz',
+      'https://example.com/jdk.tar.gz.sig',
+      customKey
+    );
+  });
+
+  it('fails when signature is missing and verification is enabled', async () => {
+    const signedDistribution = new MicrosoftDistributions({
+      version: '17',
+      architecture: 'x64',
+      packageType: 'jdk',
+      checkLatest: false,
+      verifySignature: true
+    });
+
+    await expect(
+      signedDistribution['downloadTool']({
+        version: '17.0.14+7',
+        url: 'https://example.com/jdk.tar.gz'
+      })
+    ).rejects.toThrow(
+      "Input 'verify-signature' is enabled, but no signature URL was found for Microsoft Build of OpenJDK version 17.0.14+7."
+    );
+    expect(spyVerifySignature).not.toHaveBeenCalled();
+  });
+
+  it('supports signature verification', () => {
+    expect(distribution['supportsSignatureVerification']()).toBe(true);
+  });
+});
@@ -10,12 +10,16 @@ import {
   getGitHubHttpHeaders,
   renameWinArchive
 } from '../../util';
+import * as gpg from '../../gpg';
+import {MICROSOFT_PUBLIC_KEY} from './microsoft-key';
 import * as core from '@actions/core';
 import * as tc from '@actions/tool-cache';
 import fs from 'fs';
 import path from 'path';
 import {TypedResponse} from '@actions/http-client/lib/interfaces';
 
+export {MICROSOFT_PUBLIC_KEY} from './microsoft-key';
+
 export class MicrosoftDistributions extends JavaBase {
   constructor(installerOptions: JavaInstallerOptions) {
     super('Microsoft', installerOptions);
@@ -29,6 +33,28 @@ export class MicrosoftDistributions extends JavaBase {
     );
     let javaArchivePath = await tc.downloadTool(javaRelease.url);
 
+    if (this.verifySignature) {
+      if (!javaRelease.signatureUrl) {
+        throw new Error(
+          `Input 'verify-signature' is enabled, but no signature URL was found for Microsoft Build of OpenJDK version ${javaRelease.version}.`
+        );
+      }
+      core.info(`Verifying Java package signature...`);
+      try {
+        await gpg.verifyPackageSignature(
+          javaArchivePath,
+          javaRelease.signatureUrl,
+          this.verifySignaturePublicKey ?? MICROSOFT_PUBLIC_KEY
+        );
+      } catch (error) {
+        throw new Error(
+          `Failed to verify signature for Microsoft Build of OpenJDK version ${javaRelease.version} from ${javaRelease.signatureUrl}: ${
+            (error as Error).message
+          }`
+        );
+      }
+    }
+
     core.info(`Extracting Java archive...`);
     const extension = getDownloadArchiveExtension();
     if (process.platform === 'win32') {
@@ -82,10 +108,15 @@ export class MicrosoftDistributions extends JavaBase {
 
     return {
       url: foundRelease.files[0].download_url,
+      signatureUrl: `${foundRelease.files[0].download_url}.sig`,
       version: foundRelease.version
     };
   }
 
+  protected supportsSignatureVerification(): boolean {
+    return true;
+  }
+
   private async getAvailableVersions(): Promise<tc.IToolRelease[] | null> {
     // TODO get these dynamically!
     // We will need Microsoft to add an endpoint where we can query for versions.

@@ -0,0 +1,21 @@
+// Microsoft Build of OpenJDK GPG signing key
+// Retrieved from: https://download.visualstudio.microsoft.com/download/pr/b90071e2-e0cf-4411-98be-dbeb09d67bf0/8622862bcd54206e158c5abca0582c9b/464279_464280_aoc_20210208.asc
+export const MICROSOFT_PUBLIC_KEY = `-----BEGIN PGP PUBLIC KEY BLOCK-----
+Version: BSN Pgp v1.1.0.0
+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+=rHCS
+-----END PGP PUBLIC KEY BLOCK-----`;