tls: use options in getCACertificates() with X509Certificate

doc/api/tls.md

@@ -2308,21 +2308,35 @@ const additionalCerts = ['-----BEGIN CERTIFICATE-----\n...'];
 tls.setDefaultCACertificates([...currentCerts, ...additionalCerts]);
 ```
 
-## `tls.getCACertificates([type])`
+## `tls.getCACertificates([options])`
 
 <!-- YAML
 added:
   - v23.10.0
   - v22.15.0
--->
-
-* `type` {string|undefined} The type of CA certificates that will be returned. Valid values
-  are `"default"`, `"system"`, `"bundled"` and `"extra"`.
-  **Default:** `"default"`.
-* Returns: {string\[]} An array of PEM-encoded certificates. The array may contain duplicates
-  if the same certificate is repeatedly stored in multiple sources.
-
-Returns an array containing the CA certificates from various sources, depending on `type`:
+changes:
+  - version:
+      - REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/59349
+    description: Added optional `options.type` parameter to `getCACertificates()`.
+-->
+
+* `options` {string|Object|undefined}
+  Optional. If a string, it is treated as the `type` of certificates to return.
+  If an object, it may contain:
+  * `type` {string} The type of CA certificates to return. One of `"default"`, `"system"`, `"bundled"`, or `"extra"`.
+    **Default:** `"default"`.
+  * `format` {string} The format of returned certificates. One of `"pem"`, `"der"`, or `"x509"`.
+    **Default:** `"pem"`.
+    * `"pem"` (alias: `"string"`): Returns an array of PEM-encoded certificate strings.
+    * `"der"` (alias: `"buffer"`): Returns an array of certificate data as `Buffer` objects in DER format.
+    * `"x509"`: Returns an array of [`X509Certificate`][x509certificate] instances.
+
+* Returns: {Array}
+  An array of certificate data in the specified format:
+  * PEM strings when `format` is `"pem"` (or `"string"`).
+  * `Buffer` objects containing DER data when `format` is `"der"` (or `"buffer"`).
+  * [`X509Certificate`][x509certificate] instances when `format` is `"x509"`.
 
 * `"default"`: return the CA certificates that will be used by the Node.js TLS clients by default.
   * When [`--use-bundled-ca`][] is enabled (default), or [`--use-openssl-ca`][] is not enabled,
@@ -2494,7 +2508,7 @@ added: v0.11.3
 [`tls.connect()`]: #tlsconnectoptions-callback
 [`tls.createSecureContext()`]: #tlscreatesecurecontextoptions
 [`tls.createServer()`]: #tlscreateserveroptions-secureconnectionlistener
-[`tls.getCACertificates()`]: #tlsgetcacertificatestype
+[`tls.getCACertificates()`]: #tlsgetcacertificatesoptions
 [`tls.getCiphers()`]: #tlsgetciphers
 [`tls.rootCertificates`]: #tlsrootcertificates
 [`x509.checkHost()`]: crypto.md#x509checkhostname-options
@@ -2503,3 +2517,4 @@ added: v0.11.3
 [cipher list format]: https://www.openssl.org/docs/man1.1.1/man1/ciphers.html#CIPHER-LIST-FORMAT
 [forward secrecy]: https://en.wikipedia.org/wiki/Perfect_forward_secrecy
 [perfect forward secrecy]: #perfect-forward-secrecy
+[x509certificate]: crypto.md#class-x509certificate

lib/tls.js

@@ -60,7 +60,11 @@ const { Buffer } = require('buffer');
 const { canonicalizeIP } = internalBinding('cares_wrap');
 const tlsCommon = require('internal/tls/common');
 const tlsWrap = require('internal/tls/wrap');
-const { validateString } = require('internal/validators');
+const {
+  validateOneOf,
+  validateString,
+} = require('internal/validators');
+const { X509Certificate } = require('crypto');
 
 // Allow {CLIENT_RENEG_LIMIT} client-initiated session renegotiations
 // every {CLIENT_RENEG_WINDOW} seconds. An error event is emitted if more
@@ -164,8 +168,7 @@ function cacheDefaultCACertificates() {
   return defaultCACertificates;
 }
 
-// TODO(joyeecheung): support X509Certificate output?
-function getCACertificates(type = 'default') {
+function getCACertificatesAsStrings(type = 'default') {
   validateString(type, 'type');
 
   switch (type) {
@@ -181,6 +184,44 @@ function getCACertificates(type = 'default') {
       throw new ERR_INVALID_ARG_VALUE('type', type);
   }
 }
+
+function getCACertificates(options = undefined) {
+  if (typeof options === 'string' || options === undefined) {
+    return getCACertificatesAsStrings(options);
+  }
+
+  if (typeof options === 'object' && options !== null) {
+    const {
+      type = 'default',
+      format = 'pem',
+    } = options;
+
+    validateString(type, 'type');
+    validateOneOf(format, 'format', ['pem', 'der', 'x509', 'string', 'buffer']);
+
+    const certs = getCACertificatesAsStrings(type);
+
+    if (format === 'x509') {
+      return certs.map((cert) => new X509Certificate(cert));
+    }
+
+    if (format === 'pem' || format === 'string') {
+      return certs;
+    }
+
+    const buffers = certs.map((cert) => {
+      const base64 = cert.replace(/(?:\s|-----BEGIN CERTIFICATE-----|-----END CERTIFICATE-----)+/g, '');
+      return Buffer.from(base64, 'base64');
+    });
+
+    if (format === 'der' || format === 'buffer') {
+      return buffers;
+    }
+  }
+
+  throw new ERR_INVALID_ARG_TYPE('options', ['string', 'object'], options);
+}
+
 exports.getCACertificates = getCACertificates;
 
 function setDefaultCACertificates(certs) {

test/parallel/test-tls-get-ca-certificates-default.js

@@ -13,8 +13,5 @@ const { assertIsCAArray } = require('../common/tls');
 const certs = tls.getCACertificates();
 assertIsCAArray(certs);
 
-const certs2 = tls.getCACertificates('default');
-assert.strictEqual(certs, certs2);
-
 // It's cached on subsequent accesses.
 assert.strictEqual(certs, tls.getCACertificates('default'));

test/parallel/test-tls-get-ca-certificates-x509-option.js

@@ -0,0 +1,66 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+
+const assert = require('assert');
+const tls = require('tls');
+const { X509Certificate } = require('crypto');
+
+{
+  const certs = tls.getCACertificates({ type: 'default', format: 'x509' });
+  assert.ok(Array.isArray(certs));
+  assert.ok(certs.length > 0);
+  for (const cert of certs) {
+    assert.ok(cert instanceof X509Certificate);
+  }
+}
+
+{
+  const certs = tls.getCACertificates({ type: 'default', format: 'buffer' });
+  assert.ok(Array.isArray(certs));
+  assert.ok(certs.length > 0);
+  for (const cert of certs) {
+    assert.ok(Buffer.isBuffer(cert));
+  }
+}
+
+{
+  const certs = tls.getCACertificates({ type: 'default' });
+  assert.ok(Array.isArray(certs));
+  assert.ok(certs.length > 0);
+  for (const cert of certs) {
+    assert.strictEqual(typeof cert, 'string');
+    assert.ok(cert.includes('-----BEGIN CERTIFICATE-----'));
+  }
+}
+
+{
+  assert.throws(() => {
+    tls.getCACertificates({ type: 'default', format: 'invalid' });
+  }, {
+    name: 'TypeError',
+    code: 'ERR_INVALID_ARG_VALUE',
+    message: /must be one of/
+  });
+}
+
+{
+  const certs = tls.getCACertificates({ format: 'buffer' });
+  assert.ok(Array.isArray(certs));
+  assert.ok(certs.length > 0);
+  for (const cert of certs) {
+    assert.ok(Buffer.isBuffer(cert));
+  }
+}
+
+{
+  assert.throws(() => {
+    tls.getCACertificates({ type: 'invalid', format: 'buffer' });
+  }, {
+    name: 'TypeError',
+    code: 'ERR_INVALID_ARG_VALUE',
+    message: "The argument 'type' is invalid. Received 'invalid'"
+  });
+}