1 // Copyright 2015 Joyent, Inc.
3 var assert = require('assert-plus');
4 var crypto = require('crypto');
5 var sshpk = require('sshpk');
6 var utils = require('./utils');
8 var HASH_ALGOS = utils.HASH_ALGOS;
9 var PK_ALGOS = utils.PK_ALGOS;
10 var InvalidAlgorithmError = utils.InvalidAlgorithmError;
11 var HttpSignatureError = utils.HttpSignatureError;
12 var validateAlgorithm = utils.validateAlgorithm;
18 * Verify RSA/DSA signature against public key. You are expected to pass in
19 * an object that was returned from `parse()`.
21 * @param {Object} parsedSignature the object you got from `parse`.
22 * @param {String} pubkey RSA/DSA private key PEM.
23 * @return {Boolean} true if valid, false otherwise.
24 * @throws {TypeError} if you pass in bad arguments.
25 * @throws {InvalidAlgorithmError}
27 verifySignature: function verifySignature(parsedSignature, pubkey) {
28 assert.object(parsedSignature, 'parsedSignature');
29 if (typeof (pubkey) === 'string' || Buffer.isBuffer(pubkey))
30 pubkey = sshpk.parseKey(pubkey);
31 assert.ok(sshpk.Key.isKey(pubkey, [1, 1]), 'pubkey must be a sshpk.Key');
33 var alg = validateAlgorithm(parsedSignature.algorithm);
34 if (alg[0] === 'hmac' || alg[0] !== pubkey.type)
37 var v = pubkey.createVerify(alg[1]);
38 v.update(parsedSignature.signingString);
39 return (v.verify(parsedSignature.params.signature, 'base64'));
43 * Verify HMAC against shared secret. You are expected to pass in an object
44 * that was returned from `parse()`.
46 * @param {Object} parsedSignature the object you got from `parse`.
47 * @param {String} secret HMAC shared secret.
48 * @return {Boolean} true if valid, false otherwise.
49 * @throws {TypeError} if you pass in bad arguments.
50 * @throws {InvalidAlgorithmError}
52 verifyHMAC: function verifyHMAC(parsedSignature, secret) {
53 assert.object(parsedSignature, 'parsedHMAC');
54 assert.string(secret, 'secret');
56 var alg = validateAlgorithm(parsedSignature.algorithm);
57 if (alg[0] !== 'hmac')
60 var hashAlg = alg[1].toUpperCase();
62 var hmac = crypto.createHmac(hashAlg, secret);
63 hmac.update(parsedSignature.signingString);
66 * Now double-hash to avoid leaking timing information - there's
67 * no easy constant-time compare in JS, so we use this approach
68 * instead. See for more info:
69 * https://www.isecpartners.com/blog/2011/february/double-hmac-
72 var h1 = crypto.createHmac(hashAlg, secret);
73 h1.update(hmac.digest());
75 var h2 = crypto.createHmac(hashAlg, secret);
76 h2.update(new Buffer(parsedSignature.params.signature, 'base64'));
79 /* Node 0.8 returns strings from .digest(). */
80 if (typeof (h1) === 'string')
82 /* And node 0.10 lacks the .equals() method on Buffers. */
83 if (Buffer.isBuffer(h1) && !h1.equals)
84 return (h1.toString('binary') === h2.toString('binary'));
86 return (h1.equals(h2));