amazon-cognito-identity-js
Version:
Amazon Cognito Identity Provider JavaScript SDK
377 lines (276 loc) • 14.4 kB
JavaScript
'use strict';
exports.__esModule = true;
var _buffer = require('buffer/');
var _core = require('crypto-js/core');
var _core2 = _interopRequireDefault(_core);
require('crypto-js/lib-typedarrays');
var _sha = require('crypto-js/sha256');
var _sha2 = _interopRequireDefault(_sha);
var _hmacSha = require('crypto-js/hmac-sha256');
var _hmacSha2 = _interopRequireDefault(_hmacSha);
var _BigInteger = require('./BigInteger');
var _BigInteger2 = _interopRequireDefault(_BigInteger);
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } } /*!
* Copyright 2016 Amazon.com,
* Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Amazon Software License (the "License").
* You may not use this file except in compliance with the
* License. A copy of the License is located at
*
* http://aws.amazon.com/asl/
*
* or in the "license" file accompanying this file. This file is
* distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
* CONDITIONS OF ANY KIND, express or implied. See the License
* for the specific language governing permissions and
* limitations under the License.
*/
// necessary for crypto js
var randomBytes = function randomBytes(nBytes) {
return _buffer.Buffer.from(_core2.default.lib.WordArray.random(nBytes).toString(), 'hex');
};
var initN = 'FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD1' + '29024E088A67CC74020BBEA63B139B22514A08798E3404DD' + 'EF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245' + 'E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7ED' + 'EE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3D' + 'C2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F' + '83655D23DCA3AD961C62F356208552BB9ED529077096966D' + '670C354E4ABC9804F1746C08CA18217C32905E462E36CE3B' + 'E39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9' + 'DE2BCBF6955817183995497CEA956AE515D2261898FA0510' + '15728E5A8AAAC42DAD33170D04507A33A85521ABDF1CBA64' + 'ECFB850458DBEF0A8AEA71575D060C7DB3970F85A6E1E4C7' + 'ABF5AE8CDB0933D71E8C94E04A25619DCEE3D2261AD2EE6B' + 'F12FFA06D98A0864D87602733EC86A64521F2B18177B200C' + 'BBE117577A615D6C770988C0BAD946E208E24FA074E5AB31' + '43DB5BFCE0FD108E4B82D120A93AD2CAFFFFFFFFFFFFFFFF';
var newPasswordRequiredChallengeUserAttributePrefix = 'userAttributes.';
/** @class */
var AuthenticationHelper = function () {
/**
* Constructs a new AuthenticationHelper object
* @param {string} PoolName Cognito user pool name.
*/
function AuthenticationHelper(PoolName) {
_classCallCheck(this, AuthenticationHelper);
this.N = new _BigInteger2.default(initN, 16);
this.g = new _BigInteger2.default('2', 16);
this.k = new _BigInteger2.default(this.hexHash('00' + this.N.toString(16) + '0' + this.g.toString(16)), 16);
this.smallAValue = this.generateRandomSmallA();
this.getLargeAValue(function () {});
this.infoBits = _buffer.Buffer.from('Caldera Derived Key', 'utf8');
this.poolName = PoolName;
}
/**
* @returns {BigInteger} small A, a random number
*/
AuthenticationHelper.prototype.getSmallAValue = function getSmallAValue() {
return this.smallAValue;
};
/**
* @param {nodeCallback<BigInteger>} callback Called with (err, largeAValue)
* @returns {void}
*/
AuthenticationHelper.prototype.getLargeAValue = function getLargeAValue(callback) {
var _this = this;
if (this.largeAValue) {
callback(null, this.largeAValue);
} else {
this.calculateA(this.smallAValue, function (err, largeAValue) {
if (err) {
callback(err, null);
}
_this.largeAValue = largeAValue;
callback(null, _this.largeAValue);
});
}
};
/**
* helper function to generate a random big integer
* @returns {BigInteger} a random value.
* @private
*/
AuthenticationHelper.prototype.generateRandomSmallA = function generateRandomSmallA() {
var hexRandom = randomBytes(128).toString('hex');
var randomBigInt = new _BigInteger2.default(hexRandom, 16);
var smallABigInt = randomBigInt.mod(this.N);
return smallABigInt;
};
/**
* helper function to generate a random string
* @returns {string} a random value.
* @private
*/
AuthenticationHelper.prototype.generateRandomString = function generateRandomString() {
return randomBytes(40).toString('base64');
};
/**
* @returns {string} Generated random value included in password hash.
*/
AuthenticationHelper.prototype.getRandomPassword = function getRandomPassword() {
return this.randomPassword;
};
/**
* @returns {string} Generated random value included in devices hash.
*/
AuthenticationHelper.prototype.getSaltDevices = function getSaltDevices() {
return this.SaltToHashDevices;
};
/**
* @returns {string} Value used to verify devices.
*/
AuthenticationHelper.prototype.getVerifierDevices = function getVerifierDevices() {
return this.verifierDevices;
};
/**
* Generate salts and compute verifier.
* @param {string} deviceGroupKey Devices to generate verifier for.
* @param {string} username User to generate verifier for.
* @param {nodeCallback<null>} callback Called with (err, null)
* @returns {void}
*/
AuthenticationHelper.prototype.generateHashDevice = function generateHashDevice(deviceGroupKey, username, callback) {
var _this2 = this;
this.randomPassword = this.generateRandomString();
var combinedString = '' + deviceGroupKey + username + ':' + this.randomPassword;
var hashedString = this.hash(combinedString);
var hexRandom = randomBytes(16).toString('hex');
this.SaltToHashDevices = this.padHex(new _BigInteger2.default(hexRandom, 16));
this.g.modPow(new _BigInteger2.default(this.hexHash(this.SaltToHashDevices + hashedString), 16), this.N, function (err, verifierDevicesNotPadded) {
if (err) {
callback(err, null);
}
_this2.verifierDevices = _this2.padHex(verifierDevicesNotPadded);
callback(null, null);
});
};
/**
* Calculate the client's public value A = g^a%N
* with the generated random number a
* @param {BigInteger} a Randomly generated small A.
* @param {nodeCallback<BigInteger>} callback Called with (err, largeAValue)
* @returns {void}
* @private
*/
AuthenticationHelper.prototype.calculateA = function calculateA(a, callback) {
var _this3 = this;
this.g.modPow(a, this.N, function (err, A) {
if (err) {
callback(err, null);
}
if (A.mod(_this3.N).equals(_BigInteger2.default.ZERO)) {
callback(new Error('Illegal paramater. A mod N cannot be 0.'), null);
}
callback(null, A);
});
};
/**
* Calculate the client's value U which is the hash of A and B
* @param {BigInteger} A Large A value.
* @param {BigInteger} B Server B value.
* @returns {BigInteger} Computed U value.
* @private
*/
AuthenticationHelper.prototype.calculateU = function calculateU(A, B) {
this.UHexHash = this.hexHash(this.padHex(A) + this.padHex(B));
var finalU = new _BigInteger2.default(this.UHexHash, 16);
return finalU;
};
/**
* Calculate a hash from a bitArray
* @param {Buffer} buf Value to hash.
* @returns {String} Hex-encoded hash.
* @private
*/
AuthenticationHelper.prototype.hash = function hash(buf) {
var str = buf instanceof _buffer.Buffer ? _core2.default.lib.WordArray.create(buf) : buf;
var hashHex = (0, _sha2.default)(str).toString();
return new Array(64 - hashHex.length).join('0') + hashHex;
};
/**
* Calculate a hash from a hex string
* @param {String} hexStr Value to hash.
* @returns {String} Hex-encoded hash.
* @private
*/
AuthenticationHelper.prototype.hexHash = function hexHash(hexStr) {
return this.hash(_buffer.Buffer.from(hexStr, 'hex'));
};
/**
* Standard hkdf algorithm
* @param {Buffer} ikm Input key material.
* @param {Buffer} salt Salt value.
* @returns {Buffer} Strong key material.
* @private
*/
AuthenticationHelper.prototype.computehkdf = function computehkdf(ikm, salt) {
var infoBitsWordArray = _core2.default.lib.WordArray.create(_buffer.Buffer.concat([this.infoBits, _buffer.Buffer.from(String.fromCharCode(1), 'utf8')]));
var ikmWordArray = ikm instanceof _buffer.Buffer ? _core2.default.lib.WordArray.create(ikm) : ikm;
var saltWordArray = salt instanceof _buffer.Buffer ? _core2.default.lib.WordArray.create(salt) : salt;
var prk = (0, _hmacSha2.default)(ikmWordArray, saltWordArray);
var hmac = (0, _hmacSha2.default)(infoBitsWordArray, prk);
return _buffer.Buffer.from(hmac.toString(), 'hex').slice(0, 16);
};
/**
* Calculates the final hkdf based on computed S value, and computed U value and the key
* @param {String} username Username.
* @param {String} password Password.
* @param {BigInteger} serverBValue Server B value.
* @param {BigInteger} salt Generated salt.
* @param {nodeCallback<Buffer>} callback Called with (err, hkdfValue)
* @returns {void}
*/
AuthenticationHelper.prototype.getPasswordAuthenticationKey = function getPasswordAuthenticationKey(username, password, serverBValue, salt, callback) {
var _this4 = this;
if (serverBValue.mod(this.N).equals(_BigInteger2.default.ZERO)) {
throw new Error('B cannot be zero.');
}
this.UValue = this.calculateU(this.largeAValue, serverBValue);
if (this.UValue.equals(_BigInteger2.default.ZERO)) {
throw new Error('U cannot be zero.');
}
var usernamePassword = '' + this.poolName + username + ':' + password;
var usernamePasswordHash = this.hash(usernamePassword);
var xValue = new _BigInteger2.default(this.hexHash(this.padHex(salt) + usernamePasswordHash), 16);
this.calculateS(xValue, serverBValue, function (err, sValue) {
if (err) {
callback(err, null);
}
var hkdf = _this4.computehkdf(_buffer.Buffer.from(_this4.padHex(sValue), 'hex'), _buffer.Buffer.from(_this4.padHex(_this4.UValue.toString(16)), 'hex'));
callback(null, hkdf);
});
};
/**
* Calculates the S value used in getPasswordAuthenticationKey
* @param {BigInteger} xValue Salted password hash value.
* @param {BigInteger} serverBValue Server B value.
* @param {nodeCallback<string>} callback Called on success or error.
* @returns {void}
*/
AuthenticationHelper.prototype.calculateS = function calculateS(xValue, serverBValue, callback) {
var _this5 = this;
this.g.modPow(xValue, this.N, function (err, gModPowXN) {
if (err) {
callback(err, null);
}
var intValue2 = serverBValue.subtract(_this5.k.multiply(gModPowXN));
intValue2.modPow(_this5.smallAValue.add(_this5.UValue.multiply(xValue)), _this5.N, function (err2, result) {
if (err2) {
callback(err2, null);
}
callback(null, result.mod(_this5.N));
});
});
};
/**
* Return constant newPasswordRequiredChallengeUserAttributePrefix
* @return {newPasswordRequiredChallengeUserAttributePrefix} constant prefix value
*/
AuthenticationHelper.prototype.getNewPasswordRequiredChallengeUserAttributePrefix = function getNewPasswordRequiredChallengeUserAttributePrefix() {
return newPasswordRequiredChallengeUserAttributePrefix;
};
/**
* Converts a BigInteger (or hex string) to hex format padded with zeroes for hashing
* @param {BigInteger|String} bigInt Number or string to pad.
* @returns {String} Padded hex string.
*/
AuthenticationHelper.prototype.padHex = function padHex(bigInt) {
var hashStr = bigInt.toString(16);
if (hashStr.length % 2 === 1) {
hashStr = '0' + hashStr;
} else if ('89ABCDEFabcdef'.indexOf(hashStr[0]) !== -1) {
hashStr = '00' + hashStr;
}
return hashStr;
};
return AuthenticationHelper;
}();
exports.default = AuthenticationHelper;