signal-desktop/libtextsecure/sendmessage.js
Daniel Gasienica 32911002d4 Verify makeAttachmentPointer and encryptAttachment arguments
The underlying `crypto.subtle.encrypt` API requires it.
2018-03-26 16:38:34 -04:00

765 lines
30 KiB
JavaScript

/*
* vim: ts=4:sw=4:expandtab
*/
function stringToArrayBuffer(str) {
if (typeof str !== 'string') {
throw new Error('Passed non-string to stringToArrayBuffer');
}
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 Message(options) {
this.body = options.body;
this.attachments = options.attachments || [];
this.group = options.group;
this.flags = options.flags;
this.recipients = options.recipients;
this.timestamp = options.timestamp;
this.needsSync = options.needsSync;
this.expireTimer = options.expireTimer;
this.profileKey = options.profileKey;
if (!(this.recipients instanceof Array) || this.recipients.length < 1) {
throw new Error('Invalid recipient list');
}
if (!this.group && this.recipients.length > 1) {
throw new Error('Invalid recipient list for non-group');
}
if (typeof this.timestamp !== 'number') {
throw new Error('Invalid timestamp');
}
if (this.expireTimer !== undefined && this.expireTimer !== null) {
if (typeof this.expireTimer !== 'number' || !(this.expireTimer >= 0)) {
throw new Error('Invalid expireTimer');
}
}
if (this.attachments) {
if (!(this.attachments instanceof Array)) {
throw new Error('Invalid message attachments');
}
}
if (this.flags !== undefined) {
if (typeof this.flags !== 'number') {
throw new Error('Invalid message flags');
}
}
if (this.isEndSession()) {
if (this.body !== null || this.group !== null || this.attachments.length !== 0) {
throw new Error('Invalid end session message');
}
} else {
if ( (typeof this.timestamp !== 'number') ||
(this.body && typeof this.body !== 'string') ) {
throw new Error('Invalid message body');
}
if (this.group) {
if ( (typeof this.group.id !== 'string') ||
(typeof this.group.type !== 'number') ) {
throw new Error('Invalid group context');
}
}
}
}
Message.prototype = {
constructor: Message,
isEndSession: function() {
return (this.flags & textsecure.protobuf.DataMessage.Flags.END_SESSION);
},
toProto: function() {
if (this.dataMessage instanceof textsecure.protobuf.DataMessage) {
return this.dataMessage;
}
var proto = new textsecure.protobuf.DataMessage();
if (this.body) {
proto.body = this.body;
}
proto.attachments = this.attachmentPointers;
if (this.flags) {
proto.flags = this.flags;
}
if (this.group) {
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(this.group.id);
proto.group.type = this.group.type
}
if (this.expireTimer) {
proto.expireTimer = this.expireTimer;
}
if (this.profileKey) {
proto.profileKey = this.profileKey;
}
this.dataMessage = proto;
return proto;
},
toArrayBuffer: function() {
return this.toProto().toArrayBuffer();
}
};
function MessageSender(url, username, password, cdn_url) {
this.server = new TextSecureServer(url, username, password, cdn_url);
this.pendingMessages = {};
}
MessageSender.prototype = {
constructor: MessageSender,
// makeAttachmentPointer :: Attachment -> Promise AttachmentPointerProto
makeAttachmentPointer: function(attachment) {
if (typeof attachment !== 'object' || attachment == null) {
return Promise.resolve(undefined);
}
if (!(attachment.data instanceof ArrayBuffer) &&
!ArrayBuffer.isView(attachment.data)) {
return Promise.reject(new TypeError(
'`attachment.data` must be an `ArrayBuffer` or `ArrayBufferView`; got: ' +
typeof attachment.data
));
}
var proto = new textsecure.protobuf.AttachmentPointer();
proto.key = libsignal.crypto.getRandomBytes(64);
var iv = libsignal.crypto.getRandomBytes(16);
return textsecure.crypto.encryptAttachment(attachment.data, proto.key, iv).then(function(result) {
return this.server.putAttachment(result.ciphertext).then(function(id) {
proto.id = id;
proto.contentType = attachment.contentType;
proto.digest = result.digest;
if (attachment.fileName) {
proto.fileName = attachment.fileName;
}
if (attachment.size) {
proto.size = attachment.size;
}
if (attachment.flags) {
proto.flags = attachment.flags;
}
return proto;
});
}.bind(this));
},
retransmitMessage: function(number, jsonData, timestamp) {
var outgoing = new OutgoingMessage(this.server);
return outgoing.transmitMessage(number, jsonData, timestamp);
},
validateRetryContentMessage: function(content) {
// We want at least one field set, but not more than one
var count = 0;
count += content.syncMessage ? 1 : 0;
count += content.dataMessage ? 1 : 0;
count += content.callMessage ? 1 : 0;
count += content.nullMessage ? 1 : 0;
if (count !== 1) {
return false;
}
// It's most likely that dataMessage will be populated, so we look at it in detail
var data = content.dataMessage;
if (data && !data.attachments.length && !data.body && !data.expireTimer && !data.flags && !data.group) {
return false;
}
return true;
},
getRetryProto: function(message, timestamp) {
// If message was sent before v0.41.3 was released on Aug 7, then it was most certainly a DataMessage
//
// var d = new Date('2017-08-07T07:00:00.000Z');
// d.getTime();
var august7 = 1502089200000;
if (timestamp < august7) {
return textsecure.protobuf.DataMessage.decode(message);
}
// This is ugly. But we don't know what kind of proto we need to decode...
try {
// Simply decoding as a Content message may throw
var proto = textsecure.protobuf.Content.decode(message);
// But it might also result in an invalid object, so we try to detect that
if (this.validateRetryContentMessage(proto)) {
return proto;
}
return textsecure.protobuf.DataMessage.decode(message);
} catch(e) {
// If this call throws, something has really gone wrong, we'll fail to send
return textsecure.protobuf.DataMessage.decode(message);
}
},
tryMessageAgain: function(number, encodedMessage, timestamp) {
var proto = this.getRetryProto(encodedMessage, timestamp);
return this.sendIndividualProto(number, proto, timestamp);
},
queueJobForNumber: function(number, runJob) {
var taskWithTimeout = textsecure.createTaskWithTimeout(runJob, 'queueJobForNumber ' + number);
var runPrevious = this.pendingMessages[number] || Promise.resolve();
var runCurrent = this.pendingMessages[number] = runPrevious.then(taskWithTimeout, taskWithTimeout);
runCurrent.then(function() {
if (this.pendingMessages[number] === runCurrent) {
delete this.pendingMessages[number];
}
}.bind(this));
},
uploadMedia: function(message) {
return Promise.all(
message.attachments.map(this.makeAttachmentPointer.bind(this))
).then(function(attachmentPointers) {
message.attachmentPointers = attachmentPointers;
}).catch(function(error) {
if (error instanceof Error && error.name === 'HTTPError') {
throw new textsecure.MessageError(message, error);
} else {
throw error;
}
});
},
sendMessage: function(attrs) {
var message = new Message(attrs);
return this.uploadMedia(message).then(function() {
return new Promise(function(resolve, reject) {
this.sendMessageProto(
message.timestamp,
message.recipients,
message.toProto(),
function(res) {
res.dataMessage = message.toArrayBuffer();
if (res.errors.length > 0) {
reject(res);
} else {
resolve(res);
}
}
);
}.bind(this));
}.bind(this));
},
sendMessageProto: function(timestamp, numbers, message, callback, silent) {
var rejections = textsecure.storage.get('signedKeyRotationRejected', 0);
if (rejections > 5) {
throw new textsecure.SignedPreKeyRotationError(numbers, message.toArrayBuffer(), timestamp);
}
var outgoing = new OutgoingMessage(this.server, timestamp, numbers, message, silent, callback);
numbers.forEach(function(number) {
this.queueJobForNumber(number, function() {
return outgoing.sendToNumber(number);
});
}.bind(this));
},
retrySendMessageProto: function(numbers, encodedMessage, timestamp) {
var proto = textsecure.protobuf.DataMessage.decode(encodedMessage);
return new Promise(function(resolve, reject) {
this.sendMessageProto(timestamp, numbers, proto, function(res) {
if (res.errors.length > 0) {
reject(res);
} else {
resolve(res);
}
});
}.bind(this));
},
sendIndividualProto: function(number, proto, timestamp, silent) {
return new Promise(function(resolve, reject) {
var callback = function(res) {
if (res.errors.length > 0) {
reject(res);
} else {
resolve(res);
}
};
this.sendMessageProto(timestamp, [number], proto, callback, silent);
}.bind(this));
},
createSyncMessage: function() {
var syncMessage = new textsecure.protobuf.SyncMessage();
// Generate a random int from 1 and 512
var buffer = libsignal.crypto.getRandomBytes(1);
var paddingLength = (new Uint8Array(buffer)[0] & 0x1ff) + 1;
// Generate a random padding buffer of the chosen size
syncMessage.padding = libsignal.crypto.getRandomBytes(paddingLength);
return syncMessage;
},
sendSyncMessage: function(encodedDataMessage, timestamp, destination, expirationStartTimestamp) {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
if (myDevice == 1) {
return Promise.resolve();
}
var dataMessage = textsecure.protobuf.DataMessage.decode(encodedDataMessage);
var sentMessage = new textsecure.protobuf.SyncMessage.Sent();
sentMessage.timestamp = timestamp;
sentMessage.message = dataMessage;
if (destination) {
sentMessage.destination = destination;
}
if (expirationStartTimestamp) {
sentMessage.expirationStartTimestamp = expirationStartTimestamp;
}
var syncMessage = this.createSyncMessage();
syncMessage.sent = sentMessage;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, Date.now(), silent);
},
getProfile: function(number) {
return this.server.getProfile(number);
},
getAvatar: function(path) {
return this.server.getAvatar(path);
},
sendRequestConfigurationSyncMessage: function() {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
if (myDevice != 1) {
var request = new textsecure.protobuf.SyncMessage.Request();
request.type = textsecure.protobuf.SyncMessage.Request.Type.CONFIGURATION;
var syncMessage = this.createSyncMessage();
syncMessage.request = request;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, Date.now(), silent);
}
return Promise.resolve();
},
sendRequestGroupSyncMessage: function() {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
if (myDevice != 1) {
var request = new textsecure.protobuf.SyncMessage.Request();
request.type = textsecure.protobuf.SyncMessage.Request.Type.GROUPS;
var syncMessage = this.createSyncMessage();
syncMessage.request = request;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, Date.now(), silent);
}
return Promise.resolve();
},
sendRequestContactSyncMessage: function() {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
if (myDevice != 1) {
var request = new textsecure.protobuf.SyncMessage.Request();
request.type = textsecure.protobuf.SyncMessage.Request.Type.CONTACTS;
var syncMessage = this.createSyncMessage();
syncMessage.request = request;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, Date.now(), silent);
}
return Promise.resolve();
},
sendReadReceipts: function(sender, timestamps) {
var receiptMessage = new textsecure.protobuf.ReceiptMessage();
receiptMessage.type = textsecure.protobuf.ReceiptMessage.Type.READ;
receiptMessage.timestamp = timestamps;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.receiptMessage = receiptMessage;
var silent = true;
return this.sendIndividualProto(sender, contentMessage, Date.now(), silent);
},
syncReadMessages: function(reads) {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
if (myDevice != 1) {
var syncMessage = this.createSyncMessage();
syncMessage.read = [];
for (var i = 0; i < reads.length; ++i) {
var read = new textsecure.protobuf.SyncMessage.Read();
read.timestamp = reads[i].timestamp;
read.sender = reads[i].sender;
syncMessage.read.push(read);
}
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, Date.now(), silent);
}
return Promise.resolve();
},
syncVerification: function(destination, state, identityKey) {
var myNumber = textsecure.storage.user.getNumber();
var myDevice = textsecure.storage.user.getDeviceId();
var now = Date.now();
if (myDevice == 1) {
return Promise.resolve();
}
// First send a null message to mask the sync message.
var nullMessage = new textsecure.protobuf.NullMessage();
// Generate a random int from 1 and 512
var buffer = libsignal.crypto.getRandomBytes(1);
var paddingLength = (new Uint8Array(buffer)[0] & 0x1ff) + 1;
// Generate a random padding buffer of the chosen size
nullMessage.padding = libsignal.crypto.getRandomBytes(paddingLength);
var contentMessage = new textsecure.protobuf.Content();
contentMessage.nullMessage = nullMessage;
// We want the NullMessage to look like a normal outgoing message; not silent
const promise = this.sendIndividualProto(destination, contentMessage, now);
return promise.then(function() {
var verified = new textsecure.protobuf.Verified();
verified.state = state;
verified.destination = destination;
verified.identityKey = identityKey;
verified.nullMessage = nullMessage.padding;
var syncMessage = this.createSyncMessage();
syncMessage.verified = verified;
var contentMessage = new textsecure.protobuf.Content();
contentMessage.syncMessage = syncMessage;
var silent = true;
return this.sendIndividualProto(myNumber, contentMessage, now, silent);
}.bind(this));
},
sendGroupProto: function(numbers, proto, timestamp) {
timestamp = timestamp || Date.now();
var me = textsecure.storage.user.getNumber();
numbers = numbers.filter(function(number) { return number != me; });
if (numbers.length === 0) {
return Promise.reject(new Error('No other members in the group'));
}
return new Promise(function(resolve, reject) {
var silent = true;
var callback = function(res) {
res.dataMessage = proto.toArrayBuffer();
if (res.errors.length > 0) {
reject(res);
} else {
resolve(res);
}
}.bind(this);
this.sendMessageProto(timestamp, numbers, proto, callback, silent);
}.bind(this));
},
sendMessageToNumber: function(number, messageText, attachments, timestamp, expireTimer, profileKey) {
return this.sendMessage({
recipients : [number],
body : messageText,
timestamp : timestamp,
attachments : attachments,
needsSync : true,
expireTimer : expireTimer,
profileKey : profileKey
});
},
resetSession: function(number, timestamp) {
console.log('resetting secure session');
var proto = new textsecure.protobuf.DataMessage();
proto.body = "TERMINATE";
proto.flags = textsecure.protobuf.DataMessage.Flags.END_SESSION;
var logError = function(prefix) {
return function(error) {
console.log(
prefix,
error && error.stack ? error.stack : error
);
throw error;
};
};
var deleteAllSessions = function(number) {
return textsecure.storage.protocol.getDeviceIds(number)
.then(function(deviceIds) {
return Promise.all(deviceIds.map(function(deviceId) {
var address = new libsignal.SignalProtocolAddress(number, deviceId);
console.log('deleting sessions for', address.toString());
var sessionCipher = new libsignal.SessionCipher(
textsecure.storage.protocol,
address
);
return sessionCipher.deleteAllSessionsForDevice();
}));
});
};
var sendToContact = deleteAllSessions(number)
.catch(logError('resetSession/deleteAllSessions1 error:'))
.then(function() {
console.log('finished closing local sessions, now sending to contact');
return this.sendIndividualProto(number, proto, timestamp)
.catch(logError('resetSession/sendToContact error:'))
}.bind(this))
.then(function() {
return deleteAllSessions(number)
.catch(logError('resetSession/deleteAllSessions2 error:'));
});
var buffer = proto.toArrayBuffer();
var sendSync = this.sendSyncMessage(buffer, timestamp, number)
.catch(logError('resetSession/sendSync error:'));
return Promise.all([
sendToContact,
sendSync
]);
},
sendMessageToGroup: function(groupId, messageText, attachments, timestamp, expireTimer, profileKey) {
return textsecure.storage.groups.getNumbers(groupId).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
var me = textsecure.storage.user.getNumber();
numbers = numbers.filter(function(number) { return number != me; });
if (numbers.length === 0) {
return Promise.reject(new Error('No other members in the group'));
}
return this.sendMessage({
recipients : numbers,
body : messageText,
timestamp : timestamp,
attachments : attachments,
needsSync : true,
expireTimer : expireTimer,
profileKey : profileKey,
group: {
id: groupId,
type: textsecure.protobuf.GroupContext.Type.DELIVER
}
});
}.bind(this));
},
createGroup: function(numbers, name, avatar) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
return textsecure.storage.groups.createNewGroup(numbers).then(function(group) {
proto.group.id = stringToArrayBuffer(group.id);
var numbers = group.numbers;
proto.group.type = textsecure.protobuf.GroupContext.Type.UPDATE;
proto.group.members = numbers;
proto.group.name = name;
return this.makeAttachmentPointer(avatar).then(function(attachment) {
proto.group.avatar = attachment;
return this.sendGroupProto(numbers, proto).then(function() {
return proto.group.id;
});
}.bind(this));
}.bind(this));
},
updateGroup: function(groupId, name, avatar, numbers) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(groupId);
proto.group.type = textsecure.protobuf.GroupContext.Type.UPDATE;
proto.group.name = name;
return textsecure.storage.groups.addNumbers(groupId, numbers).then(function(numbers) {
if (numbers === undefined) {
return Promise.reject(new Error("Unknown Group"));
}
proto.group.members = numbers;
return this.makeAttachmentPointer(avatar).then(function(attachment) {
proto.group.avatar = attachment;
return this.sendGroupProto(numbers, proto).then(function() {
return proto.group.id;
});
}.bind(this));
}.bind(this));
},
addNumberToGroup: function(groupId, number) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(groupId);
proto.group.type = textsecure.protobuf.GroupContext.Type.UPDATE;
return textsecure.storage.groups.addNumbers(groupId, [number]).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
proto.group.members = numbers;
return this.sendGroupProto(numbers, proto);
}.bind(this));
},
setGroupName: function(groupId, name) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(groupId);
proto.group.type = textsecure.protobuf.GroupContext.Type.UPDATE;
proto.group.name = name;
return textsecure.storage.groups.getNumbers(groupId).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
proto.group.members = numbers;
return this.sendGroupProto(numbers, proto);
}.bind(this));
},
setGroupAvatar: function(groupId, avatar) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(groupId);
proto.group.type = textsecure.protobuf.GroupContext.Type.UPDATE;
return textsecure.storage.groups.getNumbers(groupId).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
proto.group.members = numbers;
return this.makeAttachmentPointer(avatar).then(function(attachment) {
proto.group.avatar = attachment;
return this.sendGroupProto(numbers, proto);
}.bind(this));
}.bind(this));
},
leaveGroup: function(groupId) {
var proto = new textsecure.protobuf.DataMessage();
proto.group = new textsecure.protobuf.GroupContext();
proto.group.id = stringToArrayBuffer(groupId);
proto.group.type = textsecure.protobuf.GroupContext.Type.QUIT;
return textsecure.storage.groups.getNumbers(groupId).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
return textsecure.storage.groups.deleteGroup(groupId).then(function() {
return this.sendGroupProto(numbers, proto);
}.bind(this));
});
},
sendExpirationTimerUpdateToGroup: function(groupId, expireTimer, timestamp, profileKey) {
return textsecure.storage.groups.getNumbers(groupId).then(function(numbers) {
if (numbers === undefined)
return Promise.reject(new Error("Unknown Group"));
var me = textsecure.storage.user.getNumber();
numbers = numbers.filter(function(number) { return number != me; });
if (numbers.length === 0) {
return Promise.reject(new Error('No other members in the group'));
}
return this.sendMessage({
recipients : numbers,
timestamp : timestamp,
needsSync : true,
expireTimer : expireTimer,
profileKey : profileKey,
flags : textsecure.protobuf.DataMessage.Flags.EXPIRATION_TIMER_UPDATE,
group: {
id: groupId,
type: textsecure.protobuf.GroupContext.Type.DELIVER
}
});
}.bind(this));
},
sendExpirationTimerUpdateToNumber: function(number, expireTimer, timestamp, profileKey) {
var proto = new textsecure.protobuf.DataMessage();
return this.sendMessage({
recipients : [number],
timestamp : timestamp,
needsSync : true,
expireTimer : expireTimer,
profileKey : profileKey,
flags : textsecure.protobuf.DataMessage.Flags.EXPIRATION_TIMER_UPDATE
});
}
};
window.textsecure = window.textsecure || {};
textsecure.MessageSender = function(url, username, password, cdn_url) {
var sender = new MessageSender(url, username, password, cdn_url);
textsecure.replay.registerFunction(sender.tryMessageAgain.bind(sender), textsecure.replay.Type.ENCRYPT_MESSAGE);
textsecure.replay.registerFunction(sender.retransmitMessage.bind(sender), textsecure.replay.Type.TRANSMIT_MESSAGE);
textsecure.replay.registerFunction(sender.sendMessage.bind(sender), textsecure.replay.Type.REBUILD_MESSAGE);
textsecure.replay.registerFunction(sender.retrySendMessageProto.bind(sender), textsecure.replay.Type.RETRY_SEND_MESSAGE_PROTO);
this.sendExpirationTimerUpdateToNumber = sender.sendExpirationTimerUpdateToNumber.bind(sender);
this.sendExpirationTimerUpdateToGroup = sender.sendExpirationTimerUpdateToGroup .bind(sender);
this.sendRequestGroupSyncMessage = sender.sendRequestGroupSyncMessage .bind(sender);
this.sendRequestContactSyncMessage = sender.sendRequestContactSyncMessage .bind(sender);
this.sendRequestConfigurationSyncMessage = sender.sendRequestConfigurationSyncMessage.bind(sender);
this.sendMessageToNumber = sender.sendMessageToNumber .bind(sender);
this.resetSession = sender.resetSession .bind(sender);
this.sendMessageToGroup = sender.sendMessageToGroup .bind(sender);
this.createGroup = sender.createGroup .bind(sender);
this.updateGroup = sender.updateGroup .bind(sender);
this.addNumberToGroup = sender.addNumberToGroup .bind(sender);
this.setGroupName = sender.setGroupName .bind(sender);
this.setGroupAvatar = sender.setGroupAvatar .bind(sender);
this.leaveGroup = sender.leaveGroup .bind(sender);
this.sendSyncMessage = sender.sendSyncMessage .bind(sender);
this.getProfile = sender.getProfile .bind(sender);
this.getAvatar = sender.getAvatar .bind(sender);
this.syncReadMessages = sender.syncReadMessages .bind(sender);
this.syncVerification = sender.syncVerification .bind(sender);
this.sendReadReceipts = sender.sendReadReceipts .bind(sender);
};
textsecure.MessageSender.prototype = {
constructor: textsecure.MessageSender
};