signal-desktop/js/helpers.js
2014-03-09 20:32:00 -04:00

1084 lines
36 KiB
JavaScript

//TODO: Stolen from MDN (copyright...)
function b64ToUint6 (nChr) {
return nChr > 64 && nChr < 91 ?
nChr - 65
: nChr > 96 && nChr < 123 ?
nChr - 71
: nChr > 47 && nChr < 58 ?
nChr + 4
: nChr === 43 ?
62
: nChr === 47 ?
63
:
0;
}
function base64DecToArr (sBase64, nBlocksSize) {
var
sB64Enc = sBase64.replace(/[^A-Za-z0-9\+\/]/g, ""), nInLen = sB64Enc.length,
nOutLen = nBlocksSize ? Math.ceil((nInLen * 3 + 1 >> 2) / nBlocksSize) * nBlocksSize : nInLen * 3 + 1 >> 2;
var aBBytes = new ArrayBuffer(nOutLen);
var taBytes = new Uint8Array(aBBytes);
for (var nMod3, nMod4, nUint24 = 0, nOutIdx = 0, nInIdx = 0; nInIdx < nInLen; nInIdx++) {
nMod4 = nInIdx & 3;
nUint24 |= b64ToUint6(sB64Enc.charCodeAt(nInIdx)) << 18 - 6 * nMod4;
if (nMod4 === 3 || nInLen - nInIdx === 1) {
for (nMod3 = 0; nMod3 < 3 && nOutIdx < nOutLen; nMod3++, nOutIdx++) {
taBytes[nOutIdx] = nUint24 >>> (16 >>> nMod3 & 24) & 255;
}
nUint24 = 0;
}
}
return aBBytes;
}
/* Base64 string to array encoding */
function uint6ToB64 (nUint6) {
return nUint6 < 26 ?
nUint6 + 65
: nUint6 < 52 ?
nUint6 + 71
: nUint6 < 62 ?
nUint6 - 4
: nUint6 === 62 ?
43
: nUint6 === 63 ?
47
:
65;
}
function base64EncArr (aBytes) {
var nMod3, sB64Enc = "";
for (var nLen = aBytes.length, nUint24 = 0, nIdx = 0; nIdx < nLen; nIdx++) {
nMod3 = nIdx % 3;
//if (nIdx > 0 && (nIdx * 4 / 3) % 76 === 0) { sB64Enc += "\r\n"; }
nUint24 |= aBytes[nIdx] << (16 >>> nMod3 & 24);
if (nMod3 === 2 || aBytes.length - nIdx === 1) {
sB64Enc += String.fromCharCode(uint6ToB64(nUint24 >>> 18 & 63), uint6ToB64(nUint24 >>> 12 & 63), uint6ToB64(nUint24 >>> 6 & 63), uint6ToB64(nUint24 & 63));
nUint24 = 0;
}
}
return sB64Enc.replace(/A(?=A$|$)/g, "=");
}
var USE_NACL = false;
/*********************************
*** Type conversion utilities ***
*********************************/
// Strings/arrays
//TODO: Throw all this shit in favor of consistent types
var StaticByteBufferProto = new dcodeIO.ByteBuffer().__proto__;
var StaticArrayBufferProto = new ArrayBuffer().__proto__;
var StaticUint8ArrayProto = new Uint8Array().__proto__;
var StaticWordArrayProto = CryptoJS.lib.WordArray.create('').__proto__;
function getString(thing) {
if (thing === Object(thing)) {
if (thing.__proto__ == StaticUint8ArrayProto)
return String.fromCharCode.apply(null, thing);
if (thing.__proto__ == StaticArrayBufferProto)
return getString(new Uint8Array(thing));
if (thing.__proto__ == StaticByteBufferProto)
return thing.toString("binary");
if (thing.__proto__ == StaticWordArrayProto)
return thing.toString(CryptoJS.enc.Latin1);
}
return thing;
}
function getStringable(thing) {
return (typeof thing == "string" || typeof thing == "number" ||
(thing === Object(thing) &&
(thing.__proto__ == StaticArrayBufferProto ||
thing.__proto__ == StaticUint8ArrayProto ||
thing.__proto__ == StaticByteBufferProto ||
thing.__proto__ == StaticWordArrayProto)));
}
function toArrayBuffer(thing) {
//TODO: Optimize this for specific cases
if (thing === undefined)
return undefined;
if (thing === Object(thing) && thing.__proto__ == StaticArrayBufferProto)
return thing;
if (thing instanceof Array) {
// Assuming Uint16Array from curve25519
var res = new ArrayBuffer(thing.length * 2);
var uint = new Uint16Array(res);
for (var i = 0; i < thing.length; i++)
uint[i] = thing[i];
return res;
}
if (!getStringable(thing))
throw "Tried to convert a non-stringable thing of type " + typeof thing + " to an array buffer";
var str = getString(thing);
var res = new ArrayBuffer(str.length);
var uint = new Uint8Array(res);
for (var i = 0; i < str.length; i++)
uint[i] = str.charCodeAt(i);
return res;
}
function ensureStringed(thing) {
if (getStringable(thing))
return getString(thing);
else if (thing instanceof Array) {
var res = [];
for (var i = 0; i < thing.length; i++)
res[i] = ensureStringed(thing);
return res;
} else if (thing === Object(thing)) {
var res = {};
for (key in thing)
res[key] = ensureStringed(thing[key]);
return res;
}
throw "unsure of how to jsonify object of type " + typeof thing;
}
function jsonThing(thing) {
return JSON.stringify(ensureStringed(thing));
}
function getArrayBuffer(string) {
return base64DecToArr(btoa(string));
}
function base64ToArrayBuffer(string) {
return base64DecToArr(string);
}
// Protobuf decodingA
//TODO: throw on missing fields everywhere
var IncomingPushMessageProtobuf = dcodeIO.ProtoBuf.loadProtoFile("protos/IncomingPushMessageSignal.proto").build("textsecure.IncomingPushMessageSignal");
function decodeIncomingPushMessageProtobuf(string) {
return IncomingPushMessageProtobuf.decode(btoa(string));
}
var PushMessageContentProtobuf = dcodeIO.ProtoBuf.loadProtoFile("protos/IncomingPushMessageSignal.proto").build("textsecure.PushMessageContent");
function decodePushMessageContentProtobuf(string) {
return PushMessageContentProtobuf.decode(btoa(string));
}
var WhisperMessageProtobuf = dcodeIO.ProtoBuf.loadProtoFile("protos/WhisperTextProtocol.proto").build("textsecure.WhisperMessage");
function decodeWhisperMessageProtobuf(string) {
return WhisperMessageProtobuf.decode(btoa(string));
}
var PreKeyWhisperMessageProtobuf = dcodeIO.ProtoBuf.loadProtoFile("protos/WhisperTextProtocol.proto").build("textsecure.PreKeyWhisperMessage");
function decodePreKeyWhisperMessageProtobuf(string) {
return PreKeyWhisperMessageProtobuf.decode(btoa(string));
}
var KeyExchangeMessageProtobuf = dcodeIO.ProtoBuf.loadProtoFile("protos/WhisperTextProtocol.proto").build("textsecure.KeyExchangeMessage");
function decodeKeyExchangeMessageProtobuf(string) {
return KeyExchangeMessageProtobuf.decode(btoa(string));
}
// Number formatting
function getNumberFromString(string) {
return string.split(".")[0];
}
function getEncodedNumber(number) {
var split = number.split(".");
if (split.length > 1) {
if (split[1] == 1)
return split[0];
else
return number;
} else
return number;
}
function getDeviceId(encodedNumber) {
var split = encodedNumber.split(".");
if (split.length > 1)
return split[1];
return 1;
}
// Other
function timestampToHumanReadable(timestamp) {
var date = new Date();
date.setTime(timestamp*1000);
return date.toUTCString();
}
function objectContainsKeys(object) {
var count = 0;
for (key in object) {
count++;
break;
}
return count != 0;
}
/************************************************
*** Utilities to store data in local storage ***
************************************************/
var storage = {};
storage.putEncrypted = function(key, value) {
//TODO
if (value === undefined)
throw "Tried to store undefined";
localStorage.setItem("e" + key, jsonThing(value));
}
storage.getEncrypted = function(key, defaultValue) {
//TODO
var value = localStorage.getItem("e" + key);
if (value === null)
return defaultValue;
return JSON.parse(value);
}
storage.removeEncrypted = function(key) {
//TODO
}
storage.putUnencrypted = function(key, value) {
if (value === undefined)
throw "Tried to store undefined";
localStorage.setItem("u" + key, jsonThing(value));
}
storage.getUnencrypted = function(key, defaultValue) {
var value = localStorage.getItem("u" + key);
if (value === null)
return defaultValue;
return JSON.parse(value);
}
storage.removeUnencrypted = function(key) {
//TODO
}
function registrationDone() {
storage.putUnencrypted("registration_done", "");
//TODO: Fix dirty hack:
chrome.runtime.reload();
}
function isRegistrationDone() {
return storage.getUnencrypted("registration_done") !== undefined;
}
function getMessageMap() {
return storage.getEncrypted("messageMap", {});
}
function storeMessage(outgoingMessageSignal) {
var messageMap = getMessageMap();
var conversation = messageMap[outgoingMessageSignal.source]; //TODO: Also support Group message IDs here
if (conversation === undefined) {
conversation = []
messageMap[outgoingMessageSignal.source] = conversation;
}
conversation[conversation.length] = { message: getString(outgoingMessageSignal.message),
destinations: outgoingMessageSignal.destinations,
sender: outgoingMessageSignal.source,
timestamp: outgoingMessageSignal.timestamp.div(dcodeIO.Long.fromNumber(1000)).toNumber() };
storage.putEncrypted("messageMap", messageMap);
chrome.runtime.sendMessage(conversation[conversation.length - 1]);
}
function getDeviceObject(encodedNumber) {
return storage.getEncrypted("deviceObject" + getEncodedNumber(encodedNumber));
}
function getDeviceIdListFromNumber(number) {
return storage.getEncrypted("deviceIdList" + getNumberFromString(number), []);
}
function addDeviceIdForNumber(number, deviceId) {
var deviceIdList = getDeviceIdListFromNumber(getNumberFromString(number));
for (var i = 0; i < deviceIdList.length; i++) {
if (deviceIdList[i] == deviceId)
return;
}
deviceIdList[deviceIdList.length] = deviceId;
storage.putEncrypted("deviceIdList" + getNumberFromString(number), deviceIdList);
}
// throws "Identity key mismatch"
function saveDeviceObject(deviceObject) {
var existing = getDeviceObject(deviceObject.encodedNumber);
if (existing === undefined)
existing = {encodedNumber: getEncodedNumber(deviceObject.encodedNumber)};
for (key in deviceObject) {
if (key == "encodedNumber")
continue;
if (key == "identityKey" && deviceObject.identityKey != deviceObject.identityKey)
throw "Identity key mismatch";
existing[key] = deviceObject[key];
}
storage.putEncrypted("deviceObject" + getEncodedNumber(deviceObject.encodedNumber), existing);
addDeviceIdForNumber(deviceObject.encodedNumber, getDeviceId(deviceObject.encodedNumber));
}
function getDeviceObjectListFromNumber(number) {
var deviceObjectList = [];
var deviceIdList = getDeviceIdListFromNumber(number);
for (var i = 0; i < deviceIdList.length; i++)
deviceObjectList[deviceObjectList.length] = getDeviceObject(getNumberFromString(number) + "." + deviceIdList[i]);
return deviceObjectList;
}
/**********************
*** NaCL Interface ***
**********************/
var onLoadCallbacks = [];
var naclLoaded = 0;
function registerOnLoadFunction(func) {
if (naclLoaded || !USE_NACL) {
func();
return;
}
onLoadCallbacks[onLoadCallbacks.length] = func;
}
var naclMessageNextId = 0;
var naclMessageIdCallbackMap = {};
function moduleDidLoad() {
common.hideModule();
naclLoaded = 1;
for (var i = 0; i < onLoadCallbacks.length; i++)
onLoadCallbacks[i]();
onLoadCallbacks = [];
}
function handleMessage(message) {
naclMessageIdCallbackMap[message.data.call_id](message.data);
}
function postNaclMessage(message, callback) {
if (!USE_NACL)
throw "Attempted to make NaCL call with !USE_NACL?";
naclMessageIdCallbackMap[naclMessageNextId] = callback;
message.call_id = naclMessageNextId++;
common.naclModule.postMessage(message);
}
/*******************************************
*** Utilities to manage keys/randomness ***
*******************************************/
function getRandomBytes(size) {
//TODO: Better random (https://www.grc.com/r&d/js.htm?)
try {
var buffer = new ArrayBuffer(size);
var array = new Uint8Array(buffer);
window.crypto.getRandomValues(array);
return buffer;
} catch (err) {
//TODO: ummm...wat?
throw err;
}
}
// functions exposed for testing
var crypto_tests = {};
(function(crypto, $, undefined) {
crypto_tests.privToPub = function(privKey, callback) {
if (privKey.byteLength != 32)
throw "Invalid private key";
var prependVersion = function(pubKey) {
var origPub = new Uint8Array(pubKey);
var pub = new ArrayBuffer(33);
var pubWithPrefix = new Uint8Array(pub);
for (var i = 0; i < 32; i++)
pubWithPrefix[i+1] = origPub[i];
pubWithPrefix[0] = 5;
return pub;
}
if (USE_NACL) {
postNaclMessage({command: "bytesToPriv", priv: privKey}, function(message) {
postNaclMessage({command: "privToPub", priv: message.res}, function(message) {
callback({ pubKey: prependVersion(message.res), privKey: privKey });
});
});
} else {
var priv = new Uint16Array(privKey);
priv[0] &= 0xFFF8;
priv[15] = (priv[15] & 0x7FFF) | 0x4000;
//TODO: fscking type conversion
callback({ pubKey: prependVersion(toArrayBuffer(curve25519(priv))), privKey: privKey});
}
}
var createNewKeyPair = function(callback) {
crypto_tests.privToPub(getRandomBytes(32), callback);
}
var crypto_storage = {};
crypto_storage.getNewPubKeySTORINGPrivKey = function(keyName, callback) {
createNewKeyPair(function(keyPair) {
storage.putEncrypted("25519Key" + keyName, keyPair);
callback(keyPair.pubKey);
});
}
crypto_storage.getStoredPubKey = function(keyName) {
return toArrayBuffer(storage.getEncrypted("25519Key" + keyName, { pubKey: undefined }).pubKey);
}
crypto_storage.getStoredKeyPair = function(keyName) {
var res = storage.getEncrypted("25519Key" + keyName);
if (res === undefined)
return undefined;
return { pubKey: toArrayBuffer(res.pubKey), privKey: toArrayBuffer(res.privKey) };
}
crypto_storage.getAndRemoveStoredKeyPair = function(keyName) {
var keyPair = this.getStoredKeyPair(keyName);
storage.removeEncrypted("25519Key" + keyName);
return keyPair;
}
crypto_storage.getAndRemovePreKeyPair = function(keyId) {
return this.getAndRemoveStoredKeyPair("preKey" + keyId);
}
crypto_storage.getIdentityPrivKey = function() {
return this.getStoredKeyPair("identityKey").privKey;
}
crypto_storage.saveSession = function(encodedNumber, session) {
storage.putEncrypted("session" + getEncodedNumber(encodedNumber), session);
}
crypto_storage.getSession = function(encodedNumber) {
return storage.getEncrypted("session" + getEncodedNumber(encodedNumber));
}
/*****************************
*** Internal Crypto stuff ***
*****************************/
//TODO: Think about replacing CryptoJS stuff with optional NaCL-based implementations
// Probably means all of the low-level crypto stuff here needs pulled out into its own file
var ECDHE = function(pubKey, privKey, callback) {
if (privKey !== undefined) {
privKey = toArrayBuffer(privKey);
if (privKey.byteLength != 32)
throw "Invalid private key";
} else
throw "Invalid private key";
if (pubKey !== undefined) {
pubKey = toArrayBuffer(pubKey);
var pubView = new Uint8Array(pubKey);
if (pubKey.byteLength == 33 && pubView[0] == 5) {
pubKey = new ArrayBuffer(32);
var pubCopy = new Uint8Array(pubKey);
for (var i = 0; i < 32; i++)
pubCopy[i] = pubView[i+1];
} else if (pubKey.byteLength != 32)
throw "Invalid public key";
}
if (USE_NACL) {
postNaclMessage({command: "ECDHE", priv: privKey, pub: pubKey}, function(message) {
callback(message.res);
});
} else {
callback(toArrayBuffer(curve25519(new Uint16Array(privKey), new Uint16Array(pubKey))));
}
}
crypto_tests.ECDHE = ECDHE;
var HMACSHA256 = function(input, key) {
//TODO: Waaayyyy less type conversion here (probably just means replacing CryptoJS)
return CryptoJS.HmacSHA256(
CryptoJS.lib.WordArray.create(toArrayBuffer(input)),
CryptoJS.enc.Latin1.parse(getString(key)))
.toString(CryptoJS.enc.Latin1);
}
crypto_tests.HKDF = function(input, salt, info) {
// Specific implementation of RFC 5869 that only returns exactly 64 bytes
var PRK = HMACSHA256(input, salt);
var infoString = getString(info);
// TextSecure implements a slightly tweaked version of RFC 5869: the 0 and 1 should be 1 and 2 here
var T1 = HMACSHA256(infoString + String.fromCharCode(0), PRK);
var T2 = HMACSHA256(getString(T1) + infoString + String.fromCharCode(1), PRK);
return [ T1, T2 ];
}
var HKDF = function(input, salt, info) {
// HKDF for TextSecure has a bit of additional handling - salts always end up being 32 bytes
if (salt == '') {
salt = new ArrayBuffer(32);
var uintKey = new Uint8Array(salt);
for (var i = 0; i < 32; i++)
uintKey[i] = 0;
}
salt = toArrayBuffer(salt);
if (salt.byteLength != 32)
throw "Got salt of incorrect length";
return crypto_tests.HKDF(input, salt, info);
}
var decryptPaddedAES = function(ciphertext, key, iv) {
//TODO: Waaayyyy less type conversion here (probably just means replacing CryptoJS)
return CryptoJS.AES.decrypt(btoa(getString(ciphertext)),
CryptoJS.enc.Latin1.parse(getString(key)),
{iv: CryptoJS.enc.Latin1.parse(getString(iv))})
.toString(CryptoJS.enc.Latin1);
}
var decryptAESCTR = function(ciphertext, key, counter) {
//TODO: Waaayyyy less type conversion here (probably just means replacing CryptoJS)
return CryptoJS.AES.decrypt(btoa(getString(ciphertext)),
CryptoJS.enc.Latin1.parse(getString(key)),
{mode: CryptoJS.mode.CTR, iv: CryptoJS.enc.Latin1.parse(""), padding: CryptoJS.pad.NoPadding})
.toString(CryptoJS.enc.Latin1);
}
var encryptAESCTR = function(plaintext, key, counter) {
//TODO: Waaayyyy less type conversion here (probably just means replacing CryptoJS)
return CryptoJS.AES.encrypt(CryptoJS.enc.Latin1.parse(getString(plaintext)),
CryptoJS.enc.Latin1.parse(getString(key)),
{mode: CryptoJS.mode.CTR, iv: CryptoJS.enc.Latin1.parse(""), padding: CryptoJS.pad.NoPadding})
.ciphertext.toString(CryptoJS.enc.Latin1);
}
var verifyMACWithVersionByte = function(data, key, mac, version) {
if (version === undefined)
version = 1;
var calculated_mac = HMACSHA256(String.fromCharCode(version) + getString(data), key);
var macString = getString(mac);
if (calculated_mac.substring(0, macString.length) != macString)
throw "Bad MAC";
}
var calculateMACWithVersionByte = function(data, key, version) {
if (version === undefined)
version = 1;
return HMACSHA256(String.fromCharCode(version) + getString(data), key);
}
/******************************
*** Ratchet implementation ***
******************************/
var initSession = function(isInitiator, ourEphemeralKey, encodedNumber, theirIdentityPubKey, theirEphemeralPubKey, callback) {
var ourIdentityPrivKey = crypto_storage.getIdentityPrivKey();
var sharedSecret;
ECDHE(theirEphemeralPubKey, ourIdentityPrivKey, function(ecRes) {
sharedSecret = getString(ecRes);
function finishInit() {
ECDHE(theirEphemeralPubKey, ourEphemeralKey.privKey, function(ecRes) {
sharedSecret += getString(ecRes);
var masterKey = HKDF(sharedSecret, '', "WhisperText");
var session = {currentRatchet: { rootKey: masterKey[0], ephemeralKeyPair: ourEphemeralKey,
lastRemoteEphemeralKey: theirEphemeralPubKey },
oldRatchetList: []
};
session[getString(ourEphemeralKey.pubKey)] = { messageKeys: {}, chainKey: { counter: -1, key: masterKey[1] } };
// This isnt an actual ratchet, its just here to make maybeStepRatchet work
session[getString(theirEphemeralPubKey)] = { messageKeys: {}, chainKey: { counter: 0xffffffff, key: '' } };
crypto_storage.saveSession(encodedNumber, session);
callback();
});
}
if (isInitiator) {
ECDHE(theirIdentityPubKey, ourEphemeralKey.privKey, function(ecRes) {
sharedSecret = sharedSecret + getString(ecRes);
finishInit();
});
} else {
ECDHE(theirIdentityPubKey, ourEphemeralKey.privKey, function(ecRes) {
sharedSecret = getString(ecRes) + sharedSecret;
finishInit();
});
}
});
}
var initSessionFromPreKeyWhisperMessage = function(encodedNumber, message, callback) {
//TODO: Check remote identity key matches known-good key
var preKeyPair = crypto_storage.getAndRemovePreKeyPair(message.preKeyId);
if (preKeyPair === undefined)
throw "Missing preKey for PreKeyWhisperMessage";
initSession(false, preKeyPair, encodedNumber, message.identityKey, message.baseKey, function() {
callback();
});
}
var fillMessageKeys = function(chain, counter) {
var messageKeys = chain.messageKeys;
var key = chain.chainKey.key;
for (var i = chain.chainKey.counter; i < counter; i++) {
messageKeys[i + 1] = HMACSHA256(String.fromCharCode(1), key);
key = HMACSHA256(String.fromCharCode(2), key);
}
chain.chainKey.key = key;
chain.chainKey.counter = counter;
}
var maybeStepRatchet = function(session, remoteKey, previousCounter, callback) {
if (session[getString(remoteKey)] !== undefined) { //TODO: null???
callback();//TODO: This is happening in tests as alice (when bob is checking), probably shouldn't?
return;
}
var ratchet = session.currentRatchet;
var previousRatchet = session[getString(ratchet.lastRemoteEphemeralKey)];
fillMessageKeys(previousRatchet, previousCounter);
if (!objectContainsKeys(previousRatchet.messageKeys))
delete session[getString(ratchet.lastRemoteEphemeralKey)];
else
session.oldRatchetList[session.oldRatchetList.length] = { added: new Date().getTime(), ephemeralKey: ratchet.lastRemoteEphemeralKey };
delete session[ratchet.ephemeralKeyPair.pubKey];
ECDHE(remoteKey, ratchet.ephemeralKeyPair.privKey, function(sharedSecret) {
var masterKey = HKDF(sharedSecret, ratchet.rootKey, "WhisperRatchet");
session[getString(remoteKey)] = { messageKeys: {}, chainKey: { counter: -1, key: masterKey[1] } };
createNewKeyPair(function(keyPair) {
ratchet.ephemeralKeyPair = keyPair;
ECDHE(remoteKey, ratchet.ephemeralKeyPair.privKey, function(sharedSecret) {
masterKey = HKDF(sharedSecret, masterKey[0], "WhisperRatchet");
ratchet.rootKey = masterKey[0];
session[getString(ratchet.ephemeralKeyPair.pubKey)] = { messageKeys: {}, chainKey: { counter: -1, key: masterKey[1] } };
ratchet.lastRemoteEphemeralKey = remoteKey;
callback();
});
});
});
}
// returns decrypted protobuf
var decryptWhisperMessage = function(encodedNumber, messageBytes, callback) {
var session = crypto_storage.getSession(encodedNumber);
if (session === undefined)
throw "No session currently open with " + encodedNumber;
if (messageBytes[0] != String.fromCharCode((2 << 4) | 2))
throw "Bad version number on WhisperMessage";
var messageProto = messageBytes.substring(1, messageBytes.length - 8);
var mac = messageBytes.substring(messageBytes.length - 8, messageBytes.length);
var message = decodeWhisperMessageProtobuf(messageProto);
maybeStepRatchet(session, message.ephemeralKey, message.previousCounter, function() {
var chain = session[getString(message.ephemeralKey)];
fillMessageKeys(chain, message.counter);
var keys = HKDF(chain.messageKeys[message.counter], '', "WhisperMessageKeys");
delete chain.messageKeys[message.counter];
verifyMACWithVersionByte(messageProto, keys[1], mac, (2 << 4) | 2);
var plaintext = decryptAESCTR(message.ciphertext, keys[0], message.counter);
//TODO: removeOldChains(session);
crypto_storage.saveSession(encodedNumber, session);
callback(decodePushMessageContentProtobuf(plaintext));
});
}
/*************************
*** Public crypto API ***
*************************/
// Decrypts message into a raw string
crypto.decryptWebsocketMessage = function(message) {
var signaling_key = storage.getEncrypted("signaling_key"); //TODO: in crypto_storage
var aes_key = signaling_key.substring(0, 32);
var mac_key = signaling_key.substring(32, 32 + 20);
var decodedMessage = new Uint8Array(base64DecToArr(getString(message)));
if (decodedMessage[0] != 1)
throw "Got bad version number: " + decodedMessage[0];
var iv = decodedMessage.subarray(1, 1 + 16);
var ciphertext = decodedMessage.subarray(1 + 16, decodedMessage.length - 10);
var ivAndCipherText = decodedMessage.subarray(1, decodedMessage.length - 10);
var mac = decodedMessage.subarray(decodedMessage.length - 10, decodedMessage.length);
verifyMACWithVersionByte(ivAndCipherText, mac_key, mac);
return decryptPaddedAES(ciphertext, aes_key, iv);
}
crypto.handleIncomingPushMessageProto = function(proto, callback) {
switch(proto.type) {
case 0: //TYPE_MESSAGE_PLAINTEXT
callback(decodePushMessageContentProtobuf(getString(proto.message)));
break;
case 1: //TYPE_MESSAGE_CIPHERTEXT
decryptWhisperMessage(proto.source, getString(proto.message), function(result) { callback(result); });
break;
case 3: //TYPE_MESSAGE_PREKEY_BUNDLE
if (proto.message.readUint8() != (2 << 4 | 2))
throw "Bad version byte"; //TODO: I don't believe this actually happens on the wire
var preKeyProto = decodePreKeyWhisperMessageProtobuf(getString(proto.message));
initSessionFromPreKeyWhisperMessage(proto.source, preKeyProto, function() {
decryptWhisperMessage(proto.source, getString(preKeyProto.message), function(result) { callback(result); });
});
break;
}
}
// callback(encoded [PreKey]WhisperMessage)
crypto.encryptMessageFor = function(deviceObject, pushMessageContent, callback) {
var session = crypto_storage.getSession(deviceObject.encodedNumber);
var doEncryptPushMessageContent = function(callback) {
var msg = new WhisperMessageProtobuf();
var plaintext = toArrayBuffer(pushMessageContent.encode());
msg.ephemeralKey = toArrayBuffer(session.currentRatchet.ephemeralKeyPair.pubKey);
var chain = session[getString(msg.ephemeralKey)];
fillMessageKeys(chain, chain.counter + 1);
var keys = HKDF(chain.messageKeys[chain.counter], '', "WhisperMessageKeys");
delete chain.messageKeys[chain.counter];
msg.counter = chain.counter;
//TODO
msg.previousCounter = 1;
msg.ciphertext = toArrayBuffer(encryptAESCTR(plaintext, keys[0], chain.counter));
var encodedMsg = getString(msg.encode());
var mac = calculateMACWithVersionByte(encodedMsg, keys[1], (2 << 4) | 2);
var result = String.fromCharCode((2 << 4) | 2) + encodedMsg + mac.substring(0, 8);
crypto_storage.saveSession(deviceObject.encodedNumber, session);
callback(result);
}
if (session === undefined) {
var preKeyMsg = new PreKeyWhisperMessageProtobuf();
preKeyMsg.identityKey = toArrayBuffer(crypto_storage.getStoredPubKey("identityKey"));
createNewKeyPair(function(baseKey) {
preKeyMsg.baseKey = toArrayBuffer(baseKey.pubKey);
preKeyMsg.preKeyId = deviceObject.preKeyId;
initSession(true, baseKey, deviceObject.encodedNumber, deviceObject.identityKey, deviceObject.publicKey, function() {
//TODO: Delete preKey info now?
session = crypto_storage.getSession(deviceObject.encodedNumber);
//TODO: We need to step ratchet here, I think
doEncryptPushMessageContent(function(message) {
preKeyMsg.message = toArrayBuffer(message);
var result = String.fromCharCode((2 << 4) | 2) + getString(preKeyMsg.encode());
callback({type: 3, body: result});
});
});
});
} else
doEncryptPushMessageContent(function(message) {
callback({type: 1, body: getString(message)});
});
}
var GENERATE_KEYS_KEYS_GENERATED = 100;
crypto.generateKeys = function(callback) {
var identityKey = crypto_storage.getStoredPubKey("identityKey");
var identityKeyCalculated = function(pubKey) {
identityKey = pubKey;
var firstKeyId = storage.getEncrypted("maxPreKeyId", -1) + 1;
storage.putEncrypted("maxPreKeyId", firstKeyId + GENERATE_KEYS_KEYS_GENERATED);
if (firstKeyId > 16777000)
throw "You crazy motherfucker";
var keys = {};
keys.keys = [];
var keysLeft = GENERATE_KEYS_KEYS_GENERATED;
for (var i = firstKeyId; i < firstKeyId + GENERATE_KEYS_KEYS_GENERATED; i++) {
crypto_storage.getNewPubKeySTORINGPrivKey("preKey" + i, function(pubKey) {
keys.keys[i] = {keyId: i, publicKey: pubKey, identityKey: identityKey};
keysLeft--;
if (keysLeft == 0) {
// 0xFFFFFF == 16777215
keys.lastResortKey = {keyId: 16777215, publicKey: crypto_storage.getStoredPubKey("preKey16777215"), identityKey: identityKey};//TODO: Rotate lastResortKey
if (keys.lastResortKey.publicKey === undefined) {
crypto_storage.getNewPubKeySTORINGPrivKey("preKey16777215", function(pubKey) {
keys.lastResortKey.publicKey = pubKey;
callback(keys);
});
} else
callback(keys);
}
});
}
}
if (identityKey === undefined)
crypto_storage.getNewPubKeySTORINGPrivKey("identityKey", function(pubKey) { identityKeyCalculated(pubKey); });
else
identityKeyCalculated(pubKey);
}
}( window.crypto = window.crypto || {}, jQuery ));
/************************************************
*** Utilities to communicate with the server ***
************************************************/
var URL_BASE = "http://textsecure-test.herokuapp.com";
var URL_CALLS = {};
URL_CALLS['accounts'] = "/v1/accounts";
URL_CALLS['devices'] = "/v1/devices";
URL_CALLS['keys'] = "/v1/keys";
URL_CALLS['push'] = "/v1/messagesocket";
URL_CALLS['messages'] = "/v1/messages/";
/**
* REQUIRED PARAMS:
* call: URL_CALLS entry
* httpType: POST/GET/PUT/etc
* OPTIONAL PARAMS:
* success_callback: function(response object) called on success
* error_callback: function(http status code = -1 or != 200) called on failure
* urlParameters: crap appended to the url (probably including a leading /)
* user: user name to be sent in a basic auth header
* password: password to be sent in a basic auth headerA
* do_auth: alternative to user/password where user/password are figured out automagically
* jsonData: JSON data sent in the request body
*/
function doAjax(param) {
if (param.urlParameters === undefined)
param.urlParameters = "";
if (param.do_auth) {
param.user = storage.getUnencrypted("number_id");
param.password = storage.getEncrypted("password");
}
$.ajax(URL_BASE + URL_CALLS[param.call] + param.urlParameters, {
type: param.httpType,
data: jsonThing(param.jsonData),
contentType: 'application/json; charset=utf-8',
dataType: 'json',
beforeSend: function(xhr) {
if (param.user !== undefined && param.password !== undefined)
xhr.setRequestHeader("Authorization", "Basic " + btoa(getString(param.user) + ":" + getString(param.password)));
},
success: function(response, textStatus, jqXHR) {
if (param.success_callback !== undefined)
param.success_callback(response);
},
error: function(jqXHR, textStatus, errorThrown) {
var code = jqXHR.status;
if (code == 200) {// happens sometimes when we get no response (TODO: Fix server to return 204? instead)
if (param.success_callback !== undefined)
param.success_callback(null);
return;
}
if (code > 999 || code < 100)
code = -1;
if (param.error_callback !== undefined)
param.error_callback(code);
},
cache: false
});
}
// message_callback(decoded_protobuf) (use decodeMessage(proto))
function subscribeToPush(message_callback) {
var user = storage.getUnencrypted("number_id");
var password = storage.getEncrypted("password");
var request = { url: URL_BASE + URL_CALLS['push'] + "/?user=%2B" + getString(user).substring(1) + "&password=" + getString(password),
method: 'GET',
fallbackMethod: 'GET',
transport: 'websocket',
fallbackTransport: 'websocket',
logLevel: 'debug', //TODO
trackMessageLength: false,
//data: "user=" + getString(user) + "&password=" + getString(password),
onOpen: function(response) {
console.log('Connected to server using ' + response.transport);
},
onMessage: function(response) {
try {
// Some bug in Atmosphere.js is forcing trackMessageLength to true
var message = JSON.parse(response.responseBody.split("|")[1]);
} catch (e) {
console.log('Error parsing server JSON message: ' + response.responseBody.split("|")[1]);
return;
}
var proto;
try {
var plaintext = crypto.decryptWebsocketMessage(message.message);
var proto = decodeIncomingPushMessageProtobuf(plaintext);
// After this point, a) decoding errors are not the server's fault, and
// b) we should handle them gracefully and tell the user they received an invalid message
doAjax({call: 'push', httpType: 'PUT', urlParameters: '/' + message.id, do_auth: true});
} catch (e) {
console.log("Error decoding message: " + e);
return;
}
try {
crypto.handleIncomingPushMessageProto(proto, function(decrypted) {
message_callback(decrypted);
}); // Decrypts/decodes/fills in fields/etc
} catch (e) {
//TODO: Tell the user decryption failed
}
},
onError: function(response) {
console.log('Server is down :(');
//TODO: GUI
}};
$.atmosphere.subscribe(request);
}
// success_callback(identity_key), error_callback(error_msg)
function getKeysForNumber(number, success_callback, error_callback) {
doAjax({call: 'keys', httpType: 'GET', do_auth: true, urlParameters: "/" + getNumberFromString(number) + "?multikeys",
success_callback: function(response) {
for (var i = 0; i < response.length; i++) {
try {
saveDeviceObject({
encodedNumber: number + "." + response[i].deviceId,
identityKey: response[i].identityKey,
publicKey: response[i].publicKey,
preKeyId: response[i].keyId
});
} catch (e) {
error_callback(e);
return;
}
}
success_callback(response[0].identityKey);
}, error_callback: function(code) {
error_callback("Error making HTTP request: " + code);
}
});
}
// success_callback(server success/failure map), error_callback(error_msg)
// message == PushMessageContentProto (NOT STRING)
function sendMessageToDevices(deviceObjectList, message, success_callback, error_callback) {
var jsonData = [];
for (var i = 0; i < deviceObjectList.legnth; i++) {
var encryptedMsg = encryptMessageFor(deviceObjectList[i], message);
jsonData[jsonData.length] = {
type: encryptedMsg.type,
destination: deviceObjectList[i].encodedNumber,
body: encryptedMsg.body,
relay: deviceObjectList[i].relay,
timestamp: new Date().getTime()
};
//TODO: need to encrypt with session key?
}
doAjax({call: 'messages', httpType: 'POST', do_auth: true, jsonData: jsonData,
success_callback: function(result) {
if (result.missingDeviceIds.length > 0) {
var responsesLeft = result.missingDeviceIds.length;
var errorThrown = 0;
for (var i = 0; i < result.missingDeviceIds.length; i++) {
getKeysForNumber(result.missingDeviceIds[i], function(identity_key) {
responsesLeft--;
if (responsesLeft == 0 && errorThrown == 0)
sendMessageToDevices(deviceObjectList, message, success_callback, error_callback);
}, function(error_msg) {
errorThrown++;
if (errorThrown == 1)
error_callback("Failed to retreive new device keys for number " + result.missingDeviceIds[i]);
});
}
} else {
success_callback(result);
}
}, error_callback: function(code) {
error_callback("Failed to conect to data channel: " + code);
}
});
}
// success_callback(success/failure map, see second-to-last line), error_callback(error_msg)
function sendMessageToNumbers(numbers, message, success_callback, error_callback) {
var deviceObjectList = [];
var deviceDatasMissing = 0;
var loopDone = 0;
var errorThrown = 0;
for (var i = 0; i < numbers.length; i++) {
var devicesForNumber = getDeviceObjectListFromNumber(numbers[i]);
for (var j = 0; j < devicesForNumber.length; j++)
deviceObjectList[deviceObjectList.length] = devicesForNumber[j];
if (devicesForNumber.length == 0) {
deviceDatasMissing++;
getKeysForNumber(numbers[i], function(identity_key) {
deviceDatasMissing--;
if (deviceDatasMissing == 0 && loopDone && errorThrown == 0)
sendMessageToNumbers(numbers, message, success_callback, error_callback);
}, function(error_msg) {
errorThrown++;
if (errorThrown == 1)
error_callback("Failed to retreive new device keys for number " + numbers[i]);
});
}
}
if (deviceDatasMissing > 0 || errorThrown > 0) {
loopDone = 1;
return;
}
return sendMessageToDevices(deviceObjectList, message, function(result) {
var successNumbers = {};
var failureNumbers = {};
for (var i = 0; i < result.success; i++)
successNumbers[getNumberFromString(result.success[i])] = 1;
for (var i = 0; i < result.failure; i++)
failureNumbers[getNumberFromString(result.success[i])] = 1;
success_callback({success: successNumbers, failure: failureNumbers});
}, error_callback);
}
function requestIdentityPrivKeyFromMasterDevice(number, identityKey) {
sendMessageToDevices([getDeviceObject(getNumberFromString(number)) + ".1"],
{message: "Identity Key request"}, function() {}, function() {});//TODO
}