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fix: certificate in Apple Game Center auth adapter not validated [ski…
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…p release] (parse-community#8058)
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mtrezza authored Jun 17, 2022
1 parent 4a10396 commit 75af9a2
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7 changes: 7 additions & 0 deletions changelogs/CHANGELOG_release.md
Original file line number Diff line number Diff line change
@@ -1,3 +1,10 @@
## [5.2.2](https://github.com/parse-community/parse-server/compare/5.2.1...5.2.2) (2022-06-17)


### Bug Fixes

* certificate in Apple Game Center auth adapter not validated; this fixes a security vulnerability in which authentication could be bypassed using a fake certificate; if you are using the Apple Gamer Center auth adapter it is your responsibility to keep its root certificate up-to-date and we advice you read the security advisory ([GHSA-rh9j-f5f8-rvgc](https://github.com/parse-community/parse-server/security/advisories/GHSA-rh9j-f5f8-rvgc)) ([ba2b0a9](https://github.com/parse-community/parse-server/commit/ba2b0a9cb9a568817a114b132a4c2e0911d76df1))

## [5.2.1](https://github.com/parse-community/parse-server/compare/5.2.0...5.2.1) (2022-05-01)


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2 changes: 1 addition & 1 deletion package-lock.json

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2 changes: 1 addition & 1 deletion package.json
Original file line number Diff line number Diff line change
@@ -1,6 +1,6 @@
{
"name": "parse-server",
"version": "5.3.0-beta.1",
"version": "5.2.2",
"description": "An express module providing a Parse-compatible API server",
"main": "lib/index.js",
"repository": {
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130 changes: 130 additions & 0 deletions spec/AuthenticationAdapters.spec.js
Original file line number Diff line number Diff line change
Expand Up @@ -1682,7 +1682,41 @@ describe('Apple Game Center Auth adapter', () => {
const gcenter = require('../lib/Adapters/Auth/gcenter');
const fs = require('fs');
const testCert = fs.readFileSync(__dirname + '/support/cert/game_center.pem');

it('can load adapter', async () => {
const options = {
gcenter: {
rootCertificateUrl:
'https://cacerts.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crt.pem',
},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
});

it('validateAuthData should validate', async () => {
const options = {
gcenter: {
rootCertificateUrl:
'https://cacerts.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crt.pem',
},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
// real token is used
const authData = {
id: 'G:1965586982',
Expand All @@ -1698,6 +1732,15 @@ describe('Apple Game Center Auth adapter', () => {
});

it('validateAuthData invalid signature id', async () => {
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
{}
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
const authData = {
id: 'G:1965586982',
publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-6.cer',
Expand All @@ -1712,6 +1755,21 @@ describe('Apple Game Center Auth adapter', () => {
});

it('validateAuthData invalid public key http url', async () => {
const options = {
gcenter: {
rootCertificateUrl:
'https://cacerts.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crt.pem',
},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
const publicKeyUrls = [
'example.com',
'http://static.gc.apple.com/public-key/gc-prod-4.cer',
Expand Down Expand Up @@ -1739,6 +1797,78 @@ describe('Apple Game Center Auth adapter', () => {
)
);
});

it('should not validate Symantec Cert', async () => {
const options = {
gcenter: {
rootCertificateUrl:
'https://cacerts.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crt.pem',
},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
expect(() =>
gcenter.verifyPublicKeyIssuer(
testCert,
'https://static.gc.apple.com/public-key/gc-prod-4.cer'
)
);
});

it('adapter should load default cert', async () => {
const options = {
gcenter: {},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);
const previous = new Date();
await adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
);

const duration = new Date().getTime() - previous.getTime();
expect(duration).toEqual(0);
});

it('adapter should throw', async () => {
const options = {
gcenter: {
rootCertificateUrl: 'https://example.com',
},
};
const { adapter, appIds, providerOptions } = authenticationLoader.loadAuthAdapter(
'gcenter',
options
);
await expectAsync(
adapter.validateAppId(
appIds,
{ publicKeyUrl: 'https://static.gc.apple.com/public-key/gc-prod-4.cer' },
providerOptions
)
).toBeRejectedWith(
new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
'Apple Game Center auth adapter parameter `rootCertificateURL` is invalid.'
)
);
});
});

describe('phant auth adapter', () => {
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100 changes: 79 additions & 21 deletions src/Adapters/Auth/gcenter.js
Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,8 @@ const authData = {
const { Parse } = require('parse/node');
const crypto = require('crypto');
const https = require('https');

const { pki } = require('node-forge');
const ca = { cert: null, url: null };
const cache = {}; // (publicKey -> cert) cache

function verifyPublicKeyUrl(publicKeyUrl) {
Expand Down Expand Up @@ -52,39 +53,53 @@ async function getAppleCertificate(publicKeyUrl) {
path: url.pathname,
method: 'HEAD',
};
const headers = await new Promise((resolve, reject) =>
const cert_headers = await new Promise((resolve, reject) =>
https.get(headOptions, res => resolve(res.headers)).on('error', reject)
);
const validContentTypes = ['application/x-x509-ca-cert', 'application/pkix-cert'];
if (
headers['content-type'] !== 'application/pkix-cert' ||
headers['content-length'] == null ||
headers['content-length'] > 10000
!validContentTypes.includes(cert_headers['content-type']) ||
cert_headers['content-length'] == null ||
cert_headers['content-length'] > 10000
) {
throw new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
`Apple Game Center - invalid publicKeyUrl: ${publicKeyUrl}`
);
}
const { certificate, headers } = await getCertificate(publicKeyUrl);
if (headers['cache-control']) {
const expire = headers['cache-control'].match(/max-age=([0-9]+)/);
if (expire) {
cache[publicKeyUrl] = certificate;
// we'll expire the cache entry later, as per max-age
setTimeout(() => {
delete cache[publicKeyUrl];
}, parseInt(expire[1], 10) * 1000);
}
}
return verifyPublicKeyIssuer(certificate, publicKeyUrl);
}

function getCertificate(url, buffer) {
return new Promise((resolve, reject) => {
https
.get(publicKeyUrl, res => {
let data = '';
.get(url, res => {
const data = [];
res.on('data', chunk => {
data += chunk.toString('base64');
data.push(chunk);
});
res.on('end', () => {
const cert = convertX509CertToPEM(data);
if (res.headers['cache-control']) {
var expire = res.headers['cache-control'].match(/max-age=([0-9]+)/);
if (expire) {
cache[publicKeyUrl] = cert;
// we'll expire the cache entry later, as per max-age
setTimeout(() => {
delete cache[publicKeyUrl];
}, parseInt(expire[1], 10) * 1000);
}
if (buffer) {
resolve({ certificate: Buffer.concat(data), headers: res.headers });
return;
}
resolve(cert);
let cert = '';
for (const chunk of data) {
cert += chunk.toString('base64');
}
const certificate = convertX509CertToPEM(cert);
resolve({ certificate, headers: res.headers });
});
})
.on('error', reject);
Expand Down Expand Up @@ -115,6 +130,30 @@ function verifySignature(publicKey, authData) {
}
}

function verifyPublicKeyIssuer(cert, publicKeyUrl) {
const publicKeyCert = pki.certificateFromPem(cert);
if (!ca.cert) {
throw new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
'Apple Game Center auth adapter parameter `rootCertificateURL` is invalid.'
);
}
try {
if (!ca.cert.verify(publicKeyCert)) {
throw new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
`Apple Game Center - invalid publicKeyUrl: ${publicKeyUrl}`
);
}
} catch (e) {
throw new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
`Apple Game Center - invalid publicKeyUrl: ${publicKeyUrl}`
);
}
return cert;
}

// Returns a promise that fulfills if this user id is valid.
async function validateAuthData(authData) {
if (!authData.id) {
Expand All @@ -126,8 +165,27 @@ async function validateAuthData(authData) {
}

// Returns a promise that fulfills if this app id is valid.
function validateAppId() {
return Promise.resolve();
async function validateAppId(appIds, authData, options = {}) {
if (!options.rootCertificateUrl) {
options.rootCertificateUrl =
'https://cacerts.digicert.com/DigiCertTrustedG4CodeSigningRSA4096SHA3842021CA1.crt.pem';
}
if (ca.url === options.rootCertificateUrl) {
return;
}
const { certificate, headers } = await getCertificate(options.rootCertificateUrl, true);
if (
headers['content-type'] !== 'application/x-pem-file' ||
headers['content-length'] == null ||
headers['content-length'] > 10000
) {
throw new Parse.Error(
Parse.Error.OBJECT_NOT_FOUND,
'Apple Game Center auth adapter parameter `rootCertificateURL` is invalid.'
);
}
ca.cert = pki.certificateFromPem(certificate);
ca.url = options.rootCertificateUrl;
}

module.exports = {
Expand Down

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