| // Copyright 2015 Joyent, Inc. |
| |
| var assert = require('assert-plus'); |
| var crypto = require('crypto'); |
| var sshpk = require('sshpk'); |
| var utils = require('./utils'); |
| |
| var HASH_ALGOS = utils.HASH_ALGOS; |
| var PK_ALGOS = utils.PK_ALGOS; |
| var InvalidAlgorithmError = utils.InvalidAlgorithmError; |
| var HttpSignatureError = utils.HttpSignatureError; |
| var validateAlgorithm = utils.validateAlgorithm; |
| |
| ///--- Exported API |
| |
| module.exports = { |
| /** |
| * Verify RSA/DSA signature against public key. You are expected to pass in |
| * an object that was returned from `parse()`. |
| * |
| * @param {Object} parsedSignature the object you got from `parse`. |
| * @param {String} pubkey RSA/DSA private key PEM. |
| * @return {Boolean} true if valid, false otherwise. |
| * @throws {TypeError} if you pass in bad arguments. |
| * @throws {InvalidAlgorithmError} |
| */ |
| verifySignature: function verifySignature(parsedSignature, pubkey) { |
| assert.object(parsedSignature, 'parsedSignature'); |
| if (typeof (pubkey) === 'string' || Buffer.isBuffer(pubkey)) |
| pubkey = sshpk.parseKey(pubkey); |
| assert.ok(sshpk.Key.isKey(pubkey, [1, 1]), 'pubkey must be a sshpk.Key'); |
| |
| var alg = validateAlgorithm(parsedSignature.algorithm); |
| if (alg[0] === 'hmac' || alg[0] !== pubkey.type) |
| return (false); |
| |
| var v = pubkey.createVerify(alg[1]); |
| v.update(parsedSignature.signingString); |
| return (v.verify(parsedSignature.params.signature, 'base64')); |
| }, |
| |
| /** |
| * Verify HMAC against shared secret. You are expected to pass in an object |
| * that was returned from `parse()`. |
| * |
| * @param {Object} parsedSignature the object you got from `parse`. |
| * @param {String} secret HMAC shared secret. |
| * @return {Boolean} true if valid, false otherwise. |
| * @throws {TypeError} if you pass in bad arguments. |
| * @throws {InvalidAlgorithmError} |
| */ |
| verifyHMAC: function verifyHMAC(parsedSignature, secret) { |
| assert.object(parsedSignature, 'parsedHMAC'); |
| assert.string(secret, 'secret'); |
| |
| var alg = validateAlgorithm(parsedSignature.algorithm); |
| if (alg[0] !== 'hmac') |
| return (false); |
| |
| var hashAlg = alg[1].toUpperCase(); |
| |
| var hmac = crypto.createHmac(hashAlg, secret); |
| hmac.update(parsedSignature.signingString); |
| |
| /* |
| * Now double-hash to avoid leaking timing information - there's |
| * no easy constant-time compare in JS, so we use this approach |
| * instead. See for more info: |
| * https://www.isecpartners.com/blog/2011/february/double-hmac- |
| * verification.aspx |
| */ |
| var h1 = crypto.createHmac(hashAlg, secret); |
| h1.update(hmac.digest()); |
| h1 = h1.digest(); |
| var h2 = crypto.createHmac(hashAlg, secret); |
| h2.update(new Buffer(parsedSignature.params.signature, 'base64')); |
| h2 = h2.digest(); |
| |
| /* Node 0.8 returns strings from .digest(). */ |
| if (typeof (h1) === 'string') |
| return (h1 === h2); |
| /* And node 0.10 lacks the .equals() method on Buffers. */ |
| if (Buffer.isBuffer(h1) && !h1.equals) |
| return (h1.toString('binary') === h2.toString('binary')); |
| |
| return (h1.equals(h2)); |
| } |
| }; |