Parse Server: Account takeover via JWT algorithm confusion in Google auth adapter

@@ -500,19 +500,60 @@ describe('google auth adapter', () => {
     }
   });
 
-  // it('should throw error if public key used to encode token is not available', async () => {
-  //   const fakeDecodedToken = { header: { kid: '789', alg: 'RS256' } };
-  //   try {
-  //     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
-
-  //     await google.validateAuthData({ id: 'the_user_id', id_token: 'the_token' }, {});
-  //     fail();
-  //   } catch (e) {
-  //     expect(e.message).toBe(
-  //       `Unable to find matching key for Key ID: ${fakeDecodedToken.header.kid}`
-  //     );
-  //   }
-  // });
+  it('should reject forged alg:none JWT from advisory PoC (GHSA-4q3h-vp4r-prv2)', async () => {
+    const header = Buffer.from('{"alg":"none","kid":"nonexistent-key","typ":"JWT"}').toString('base64url');
+    const payload = Buffer.from('{"sub":"the_user_id","iss":"accounts.google.com","aud":"secret","exp":9999999999}').toString('base64url');
+    const forgedToken = `${header}.${payload}.`;
+
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+
+    try {
+      await google.validateAuthData(
+        { id: 'the_user_id', id_token: forgedToken },
+        { clientId: 'secret' }
+      );
+      fail('should have rejected forged token');
+    } catch (e) {
+      expect(e.code).toBe(Parse.Error.OBJECT_NOT_FOUND);
+    }
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg', async () => {
+    const fakeClaim = {
+      iss: 'https://accounts.google.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'ES256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await google.validateAuthData(
+      { id: 'the_user_id', id_token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should throw error if Google signing key is not found', async () => {
+    const fakeDecodedToken = { kid: '789', alg: 'RS256' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.rejectWith(new Error('key not found'));
+
+    try {
+      await google.validateAuthData(
+        { id: 'the_user_id', id_token: 'the_token' },
+        { clientId: 'secret' }
+      );
+      fail('should have thrown');
+    } catch (e) {
+      expect(e.message).toBe('Unable to find matching key for Key ID: 789');
+    }
+  });
 
   it('(using client id as string) should verify id_token (google.com)', async () => {
     const fakeClaim = {
@@ -521,8 +562,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     const result = await google.validateAuthData(
@@ -537,8 +580,10 @@ describe('google auth adapter', () => {
       iss: 'https://not.google.com',
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -561,8 +606,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -583,8 +630,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -897,7 +946,27 @@ describe('apple signin auth adapter', () => {
       { clientId: 'secret' }
     );
     expect(result).toEqual(fakeClaim);
-    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(fakeDecodedToken.header.alg);
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg (GHSA-4q3h-vp4r-prv2)', async () => {
+    const fakeClaim = {
+      iss: 'https://appleid.apple.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'none' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await apple.validateAuthData(
+      { id: 'the_user_id', token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
   });
 
   it('should not verify invalid id_token', async () => {
@@ -1236,7 +1305,27 @@ describe('facebook limited auth adapter', () => {
       { clientId: 'secret' }
     );
     expect(result).toEqual(fakeClaim);
-    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(fakeDecodedToken.header.alg);
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg (GHSA-4q3h-vp4r-prv2)', async () => {
+    const fakeClaim = {
+      iss: 'https://www.facebook.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'none' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await facebook.validateAuthData(
+      { id: 'the_user_id', token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
   });
 
   it('should not verify invalid id_token', async () => {

@@ -673,8 +673,10 @@ describe('server', () => {
           exp: Date.now(),
           sub: 'the_user_id',
         };
-        const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+        const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+        const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
         spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+        spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
         spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
         const user = new Parse.User();
         user

@@ -77,7 +77,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, `id token is invalid for this user.`);
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
   const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
 
@@ -89,7 +89,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
 
   try {
     jwtClaims = jwt.verify(token, signingKey, {
-      algorithms: algorithm,
+      algorithms: ['RS256'],
       // the audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.
       audience: clientId,
     });

@@ -136,7 +136,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'id token is invalid for this user.');
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
   const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
 
@@ -148,7 +148,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
 
   try {
     jwtClaims = jwt.verify(token, signingKey, {
-      algorithms: algorithm,
+      algorithms: ['RS256'],
       // the audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.
       audience: clientId,
     });

@@ -4,6 +4,8 @@
  * @class GoogleAdapter
  * @param {Object} options - The adapter configuration options.
  * @param {string} options.clientId - Your Google application Client ID. Required for authentication.
+ * @param {number} [options.cacheMaxEntries] - Maximum number of JWKS cache entries. Default: 5.
+ * @param {number} [options.cacheMaxAge] - Maximum age of JWKS cache entries in ms. Default: 3600000 (1 hour).
  *
  * @description
  * ## Parse Server Configuration
@@ -21,93 +23,74 @@
  * The adapter requires the following `authData` fields:
  * - **id**: The Google user ID.
  * - **id_token**: The Google ID token.
- * - **access_token**: The Google access token.
  *
  * ## Auth Payload
  * ### Example Auth Data Payload
  * ```json
  * {
  *   "google": {
  *     "id": "1234567",
- *     "id_token": "xxxxx.yyyyy.zzzzz",
- *     "access_token": "abc123def456ghi789"
+ *     "id_token": "xxxxx.yyyyy.zzzzz"
  *   }
  * }
  * ```
  *
  * ## Notes
  * - Ensure your Google Client ID is configured properly in the Parse Server configuration.
- * - The `id_token` and `access_token` are validated against Google's authentication services.
+ * - The `id_token` is validated against Google's authentication services.
  *
  * @see {@link https://developers.google.com/identity/sign-in/web/backend-auth Google Authentication Documentation}
  */
 
 'use strict';
 
-// Helper functions for accessing the google API.
 var Parse = require('parse/node').Parse;
 
-const https = require('https');
+const jwksClient = require('jwks-rsa');
 const jwt = require('jsonwebtoken');
 const authUtils = require('./utils');
 
 const TOKEN_ISSUER = 'accounts.google.com';
 const HTTPS_TOKEN_ISSUER = 'https://accounts.google.com';
 
-let cache = {};
+const getGoogleKeyByKeyId = async (keyId, cacheMaxEntries, cacheMaxAge) => {
+  const client = jwksClient({
+    jwksUri: 'https://www.googleapis.com/oauth2/v3/certs',
+    cache: true,
+    cacheMaxEntries,
+    cacheMaxAge,
+  });
 
-// Retrieve Google Signin Keys (with cache control)
-function getGoogleKeyByKeyId(keyId) {
-  if (cache[keyId] && cache.expiresAt > new Date()) {
-    return cache[keyId];
+  let key;
+  try {
+    key = await authUtils.getSigningKey(client, keyId);
+  } catch {
+    throw new Parse.Error(
+      Parse.Error.OBJECT_NOT_FOUND,
+      `Unable to find matching key for Key ID: ${keyId}`
+    );
   }
+  return key;
+};
 
-  return new Promise((resolve, reject) => {
-    https
-      .get(`https://www.googleapis.com/oauth2/v3/certs`, res => {
-        let data = '';
-        res.on('data', chunk => {
-          data += chunk.toString('utf8');
-        });
-        res.on('end', () => {
-          const { keys } = JSON.parse(data);
-          const pems = keys.reduce(
-            (pems, { n: modulus, e: exposant, kid }) =>
-              Object.assign(pems, {
-                [kid]: rsaPublicKeyToPEM(modulus, exposant),
-              }),
-            {}
-          );
-
-          if (res.headers['cache-control']) {
-            var expire = res.headers['cache-control'].match(/max-age=([0-9]+)/);
-
-            if (expire) {
-              cache = Object.assign({}, pems, {
-                expiresAt: new Date(new Date().getTime() + Number(expire[1]) * 1000),
-              });
-            }
-          }
-
-          resolve(pems[keyId]);
-        });
-      })
-      .on('error', reject);
-  });
-}
-
-async function verifyIdToken({ id_token: token, id }, { clientId }) {
+async function verifyIdToken({ id_token: token, id }, { clientId, cacheMaxEntries, cacheMaxAge }) {
   if (!token) {
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, `id token is invalid for this user.`);
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
+  const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
-  const googleKey = await getGoogleKeyByKeyId(keyId);
+
+  cacheMaxAge = cacheMaxAge || ONE_HOUR_IN_MS;
+  cacheMaxEntries = cacheMaxEntries || 5;
+
+  const googleKey = await getGoogleKeyByKeyId(keyId, cacheMaxEntries, cacheMaxAge);
+  const signingKey = googleKey.publicKey || googleKey.rsaPublicKey;
 
   try {
-    jwtClaims = jwt.verify(token, googleKey, {
-      algorithms: algorithm,
+    jwtClaims = jwt.verify(token, signingKey, {
+      algorithms: ['RS256'],
       audience: clientId,
     });
   } catch (exception) {
@@ -150,57 +133,3 @@ module.exports = {
   validateAppId: validateAppId,
   validateAuthData: validateAuthData,
 };
-
-// Helpers functions to convert the RSA certs to PEM (from jwks-rsa)
-function rsaPublicKeyToPEM(modulusB64, exponentB64) {
-  const modulus = new Buffer(modulusB64, 'base64');
-  const exponent = new Buffer(exponentB64, 'base64');
-  const modulusHex = prepadSigned(modulus.toString('hex'));
-  const exponentHex = prepadSigned(exponent.toString('hex'));
-  const modlen = modulusHex.length / 2;
-  const explen = exponentHex.length / 2;
-
-  const encodedModlen = encodeLengthHex(modlen);
-  const encodedExplen = encodeLengthHex(explen);
-  const encodedPubkey =
-    '30' +
-    encodeLengthHex(modlen + explen + encodedModlen.length / 2 + encodedExplen.length / 2 + 2) +
-    '02' +
-    encodedModlen +
-    modulusHex +
-    '02' +
-    encodedExplen +
-    exponentHex;
-
-  const der = new Buffer(encodedPubkey, 'hex').toString('base64');
-
-  let pem = '-----BEGIN RSA PUBLIC KEY-----\n';
-  pem += `${der.match(/.{1,64}/g).join('\n')}`;
-  pem += '\n-----END RSA PUBLIC KEY-----\n';
-  return pem;
-}
-
-function prepadSigned(hexStr) {
-  const msb = hexStr[0];
-  if (msb < '0' || msb > '7') {
-    return `00${hexStr}`;
-  }
-  return hexStr;
-}
-
-function toHex(number) {
-  const nstr = number.toString(16);
-  if (nstr.length % 2) {
-    return `0${nstr}`;
-  }
-  return nstr;
-}
-
-function encodeLengthHex(n) {
-  if (n <= 127) {
-    return toHex(n);
-  }
-  const nHex = toHex(n);
-  const lengthOfLengthByte = 128 + nHex.length / 2;
-  return toHex(lengthOfLengthByte) + nHex;
-}

@@ -500,19 +500,60 @@ describe('google auth adapter', () => {
     }
   });
 
-  // it('should throw error if public key used to encode token is not available', async () => {
-  //   const fakeDecodedToken = { header: { kid: '789', alg: 'RS256' } };
-  //   try {
-  //     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
-
-  //     await google.validateAuthData({ id: 'the_user_id', id_token: 'the_token' }, {});
-  //     fail();
-  //   } catch (e) {
-  //     expect(e.message).toBe(
-  //       `Unable to find matching key for Key ID: ${fakeDecodedToken.header.kid}`
-  //     );
-  //   }
-  // });
+  it('should reject forged alg:none JWT from advisory PoC (GHSA-4q3h-vp4r-prv2)', async () => {
+    const header = Buffer.from('{"alg":"none","kid":"nonexistent-key","typ":"JWT"}').toString('base64url');
+    const payload = Buffer.from('{"sub":"the_user_id","iss":"accounts.google.com","aud":"secret","exp":9999999999}').toString('base64url');
+    const forgedToken = `${header}.${payload}.`;
+
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+
+    try {
+      await google.validateAuthData(
+        { id: 'the_user_id', id_token: forgedToken },
+        { clientId: 'secret' }
+      );
+      fail('should have rejected forged token');
+    } catch (e) {
+      expect(e.code).toBe(Parse.Error.OBJECT_NOT_FOUND);
+    }
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg', async () => {
+    const fakeClaim = {
+      iss: 'https://accounts.google.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'ES256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await google.validateAuthData(
+      { id: 'the_user_id', id_token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should throw error if Google signing key is not found', async () => {
+    const fakeDecodedToken = { kid: '789', alg: 'RS256' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.rejectWith(new Error('key not found'));
+
+    try {
+      await google.validateAuthData(
+        { id: 'the_user_id', id_token: 'the_token' },
+        { clientId: 'secret' }
+      );
+      fail('should have thrown');
+    } catch (e) {
+      expect(e.message).toBe('Unable to find matching key for Key ID: 789');
+    }
+  });
 
   it('(using client id as string) should verify id_token (google.com)', async () => {
     const fakeClaim = {
@@ -521,8 +562,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     const result = await google.validateAuthData(
@@ -537,8 +580,10 @@ describe('google auth adapter', () => {
       iss: 'https://not.google.com',
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -561,8 +606,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -583,8 +630,10 @@ describe('google auth adapter', () => {
       exp: Date.now(),
       sub: 'the_user_id',
     };
-    const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+    const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
     spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
     spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
 
     try {
@@ -897,7 +946,27 @@ describe('apple signin auth adapter', () => {
       { clientId: 'secret' }
     );
     expect(result).toEqual(fakeClaim);
-    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(fakeDecodedToken.header.alg);
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg (GHSA-4q3h-vp4r-prv2)', async () => {
+    const fakeClaim = {
+      iss: 'https://appleid.apple.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'none' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await apple.validateAuthData(
+      { id: 'the_user_id', token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
   });
 
   it('should not verify invalid id_token', async () => {
@@ -1236,7 +1305,27 @@ describe('facebook limited auth adapter', () => {
       { clientId: 'secret' }
     );
     expect(result).toEqual(fakeClaim);
-    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(fakeDecodedToken.header.alg);
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
+  });
+
+  it('should pass hardcoded RS256 algorithm to jwt.verify, not the JWT header alg (GHSA-4q3h-vp4r-prv2)', async () => {
+    const fakeClaim = {
+      iss: 'https://www.facebook.com',
+      aud: 'secret',
+      exp: Date.now(),
+      sub: 'the_user_id',
+    };
+    const fakeDecodedToken = { kid: '123', alg: 'none' };
+    const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
+    spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+    spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
+    spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+
+    await facebook.validateAuthData(
+      { id: 'the_user_id', token: 'the_token' },
+      { clientId: 'secret' }
+    );
+    expect(jwt.verify.calls.first().args[2].algorithms).toEqual(['RS256']);
   });
 
   it('should not verify invalid id_token', async () => {

@@ -673,8 +673,10 @@ describe('server', () => {
           exp: Date.now(),
           sub: 'the_user_id',
         };
-        const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+        const fakeDecodedToken = { kid: '123', alg: 'RS256' };
+        const fakeSigningKey = { kid: '123', rsaPublicKey: 'the_rsa_public_key' };
         spyOn(authUtils, 'getHeaderFromToken').and.callFake(() => fakeDecodedToken);
+        spyOn(authUtils, 'getSigningKey').and.resolveTo(fakeSigningKey);
         spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
         const user = new Parse.User();
         user

@@ -77,7 +77,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, `id token is invalid for this user.`);
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
   const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
 
@@ -89,7 +89,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
 
   try {
     jwtClaims = jwt.verify(token, signingKey, {
-      algorithms: algorithm,
+      algorithms: ['RS256'],
       // the audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.
       audience: clientId,
     });

@@ -136,7 +136,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, 'id token is invalid for this user.');
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
   const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
 
@@ -148,7 +148,7 @@ const verifyIdToken = async ({ token, id }, { clientId, cacheMaxEntries, cacheMa
 
   try {
     jwtClaims = jwt.verify(token, signingKey, {
-      algorithms: algorithm,
+      algorithms: ['RS256'],
       // the audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.
       audience: clientId,
     });

@@ -4,6 +4,8 @@
  * @class GoogleAdapter
  * @param {Object} options - The adapter configuration options.
  * @param {string} options.clientId - Your Google application Client ID. Required for authentication.
+ * @param {number} [options.cacheMaxEntries] - Maximum number of JWKS cache entries. Default: 5.
+ * @param {number} [options.cacheMaxAge] - Maximum age of JWKS cache entries in ms. Default: 3600000 (1 hour).
  *
  * @description
  * ## Parse Server Configuration
@@ -21,93 +23,74 @@
  * The adapter requires the following `authData` fields:
  * - **id**: The Google user ID.
  * - **id_token**: The Google ID token.
- * - **access_token**: The Google access token.
  *
  * ## Auth Payload
  * ### Example Auth Data Payload
  * ```json
  * {
  *   "google": {
  *     "id": "1234567",
- *     "id_token": "xxxxx.yyyyy.zzzzz",
- *     "access_token": "abc123def456ghi789"
+ *     "id_token": "xxxxx.yyyyy.zzzzz"
  *   }
  * }
  * ```
  *
  * ## Notes
  * - Ensure your Google Client ID is configured properly in the Parse Server configuration.
- * - The `id_token` and `access_token` are validated against Google's authentication services.
+ * - The `id_token` is validated against Google's authentication services.
  *
  * @see {@link https://developers.google.com/identity/sign-in/web/backend-auth Google Authentication Documentation}
  */
 
 'use strict';
 
-// Helper functions for accessing the google API.
 var Parse = require('parse/node').Parse;
 
-const https = require('https');
+const jwksClient = require('jwks-rsa');
 const jwt = require('jsonwebtoken');
 const authUtils = require('./utils');
 
 const TOKEN_ISSUER = 'accounts.google.com';
 const HTTPS_TOKEN_ISSUER = 'https://accounts.google.com';
 
-let cache = {};
+const getGoogleKeyByKeyId = async (keyId, cacheMaxEntries, cacheMaxAge) => {
+  const client = jwksClient({
+    jwksUri: 'https://www.googleapis.com/oauth2/v3/certs',
+    cache: true,
+    cacheMaxEntries,
+    cacheMaxAge,
+  });
 
-// Retrieve Google Signin Keys (with cache control)
-function getGoogleKeyByKeyId(keyId) {
-  if (cache[keyId] && cache.expiresAt > new Date()) {
-    return cache[keyId];
+  let key;
+  try {
+    key = await authUtils.getSigningKey(client, keyId);
+  } catch {
+    throw new Parse.Error(
+      Parse.Error.OBJECT_NOT_FOUND,
+      `Unable to find matching key for Key ID: ${keyId}`
+    );
   }
+  return key;
+};
 
-  return new Promise((resolve, reject) => {
-    https
-      .get(`https://www.googleapis.com/oauth2/v3/certs`, res => {
-        let data = '';
-        res.on('data', chunk => {
-          data += chunk.toString('utf8');
-        });
-        res.on('end', () => {
-          const { keys } = JSON.parse(data);
-          const pems = keys.reduce(
-            (pems, { n: modulus, e: exposant, kid }) =>
-              Object.assign(pems, {
-                [kid]: rsaPublicKeyToPEM(modulus, exposant),
-              }),
-            {}
-          );
-
-          if (res.headers['cache-control']) {
-            var expire = res.headers['cache-control'].match(/max-age=([0-9]+)/);
-
-            if (expire) {
-              cache = Object.assign({}, pems, {
-                expiresAt: new Date(new Date().getTime() + Number(expire[1]) * 1000),
-              });
-            }
-          }
-
-          resolve(pems[keyId]);
-        });
-      })
-      .on('error', reject);
-  });
-}
-
-async function verifyIdToken({ id_token: token, id }, { clientId }) {
+async function verifyIdToken({ id_token: token, id }, { clientId, cacheMaxEntries, cacheMaxAge }) {
   if (!token) {
     throw new Parse.Error(Parse.Error.OBJECT_NOT_FOUND, `id token is invalid for this user.`);
   }
 
-  const { kid: keyId, alg: algorithm } = authUtils.getHeaderFromToken(token);
+  const { kid: keyId } = authUtils.getHeaderFromToken(token);
+  const ONE_HOUR_IN_MS = 3600000;
   let jwtClaims;
-  const googleKey = await getGoogleKeyByKeyId(keyId);
+
+  cacheMaxAge = cacheMaxAge || ONE_HOUR_IN_MS;
+  cacheMaxEntries = cacheMaxEntries || 5;
+
+  const googleKey = await getGoogleKeyByKeyId(keyId, cacheMaxEntries, cacheMaxAge);
+  const signingKey = googleKey.publicKey || googleKey.rsaPublicKey;
 
   try {
-    jwtClaims = jwt.verify(token, googleKey, {
-      algorithms: algorithm,
+    jwtClaims = jwt.verify(token, signingKey, {
+      algorithms: ['RS256'],
       audience: clientId,
     });
   } catch (exception) {
@@ -150,57 +133,3 @@ module.exports = {
   validateAppId: validateAppId,
   validateAuthData: validateAuthData,
 };
-
-// Helpers functions to convert the RSA certs to PEM (from jwks-rsa)
-function rsaPublicKeyToPEM(modulusB64, exponentB64) {
-  const modulus = new Buffer(modulusB64, 'base64');
-  const exponent = new Buffer(exponentB64, 'base64');
-  const modulusHex = prepadSigned(modulus.toString('hex'));
-  const exponentHex = prepadSigned(exponent.toString('hex'));
-  const modlen = modulusHex.length / 2;
-  const explen = exponentHex.length / 2;
-
-  const encodedModlen = encodeLengthHex(modlen);
-  const encodedExplen = encodeLengthHex(explen);
-  const encodedPubkey =
-    '30' +
-    encodeLengthHex(modlen + explen + encodedModlen.length / 2 + encodedExplen.length / 2 + 2) +
-    '02' +
-    encodedModlen +
-    modulusHex +
-    '02' +
-    encodedExplen +
-    exponentHex;
-
-  const der = new Buffer(encodedPubkey, 'hex').toString('base64');
-
-  let pem = '-----BEGIN RSA PUBLIC KEY-----\n';
-  pem += `${der.match(/.{1,64}/g).join('\n')}`;
-  pem += '\n-----END RSA PUBLIC KEY-----\n';
-  return pem;
-}
-
-function prepadSigned(hexStr) {
-  const msb = hexStr[0];
-  if (msb < '0' || msb > '7') {
-    return `00${hexStr}`;
-  }
-  return hexStr;
-}
-
-function toHex(number) {
-  const nstr = number.toString(16);
-  if (nstr.length % 2) {
-    return `0${nstr}`;
-  }
-  return nstr;
-}
-
-function encodeLengthHex(n) {
-  if (n <= 127) {
-    return toHex(n);
-  }
-  const nHex = toHex(n);
-  const lengthOfLengthByte = 128 + nHex.length / 2;
-  return toHex(lengthOfLengthByte) + nHex;
-}