session-desktop/libtextsecure/outgoing_message.js

function OutgoingMessage(
  server,
  timestamp,
  numbers,
  message,
  silent,
  callback
) {
  if (message instanceof textsecure.protobuf.DataMessage) {
    var content = new textsecure.protobuf.Content();
    content.dataMessage = message;
    message = content;
  }
  this.server = server;
  this.timestamp = timestamp;
  this.numbers = numbers;
  this.message = message; // ContentMessage proto
  this.callback = callback;
  this.silent = silent;

  this.numbersCompleted = 0;
  this.errors = [];
  this.successfulNumbers = [];
}

OutgoingMessage.prototype = {
  constructor: OutgoingMessage,
  numberCompleted: function() {
    this.numbersCompleted++;
    if (this.numbersCompleted >= this.numbers.length) {
      this.callback({
        successfulNumbers: this.successfulNumbers,
        errors: this.errors,
      });
    }
  },
  registerError: function(number, reason, error) {
    if (!error || (error.name === 'HTTPError' && error.code !== 404)) {
      error = new textsecure.OutgoingMessageError(
        number,
        this.message.toArrayBuffer(),
        this.timestamp,
        error
      );
    }

    error.number = number;
    error.reason = reason;
    this.errors[this.errors.length] = error;
    this.numberCompleted();
  },
  reloadDevicesAndSend: function(number, recurse) {
    return function() {
      return textsecure.storage.protocol.getDeviceIds(number).then(
        function(deviceIds) {
          if (deviceIds.length == 0) {
            return this.registerError(
              number,
              'Got empty device list when loading device keys',
              null
            );
          }
          return this.doSendMessage(number, deviceIds, recurse);
        }.bind(this)
      );
    }.bind(this);
  },

  getKeysForNumber: function(number, updateDevices) {
    var handleResult = function(response) {
      return Promise.all(
        response.devices.map(
          function(device) {
            device.identityKey = response.identityKey;
            if (
              updateDevices === undefined ||
              updateDevices.indexOf(device.deviceId) > -1
            ) {
              var address = new libsignal.SignalProtocolAddress(
                number,
                device.deviceId
              );
              var builder = new libsignal.SessionBuilder(
                textsecure.storage.protocol,
                address
              );
              if (device.registrationId === 0) {
                console.log('device registrationId 0!');
              }
              return builder.processPreKey(device).catch(
                function(error) {
                  if (error.message === 'Identity key changed') {
                    error.timestamp = this.timestamp;
                    error.originalMessage = this.message.toArrayBuffer();
                    error.identityKey = device.identityKey;
                  }
                  throw error;
                }.bind(this)
              );
            }
          }.bind(this)
        )
      );
    }.bind(this);

    if (updateDevices === undefined) {
      return this.server.getKeysForNumber(number).then(handleResult);
    } else {
      var promise = Promise.resolve();
      updateDevices.forEach(
        function(device) {
          promise = promise.then(
            function() {
              return this.server
                .getKeysForNumber(number, device)
                .then(handleResult)
                .catch(
                  function(e) {
                    if (e.name === 'HTTPError' && e.code === 404) {
                      if (device !== 1) {
                        return this.removeDeviceIdsForNumber(number, [device]);
                      } else {
                        throw new textsecure.UnregisteredUserError(number, e);
                      }
                    } else {
                      throw e;
                    }
                  }.bind(this)
                );
            }.bind(this)
          );
        }.bind(this)
      );

      return promise;
    }
  },

  transmitMessage: function(number, jsonData, timestamp) {
    return this.server
      .sendMessages(number, jsonData, timestamp, this.silent)
      .catch(function(e) {
        if (e.name === 'HTTPError' && (e.code !== 409 && e.code !== 410)) {
          // 409 and 410 should bubble and be handled by doSendMessage
          // 404 should throw UnregisteredUserError
          // all other network errors can be retried later.
          if (e.code === 404) {
            throw new textsecure.UnregisteredUserError(number, e);
          }
          throw new textsecure.SendMessageNetworkError(
            number,
            jsonData,
            e,
            timestamp
          );
        }
        throw e;
      });
  },

  getPaddedMessageLength: function(messageLength) {
    var messageLengthWithTerminator = messageLength + 1;
    var messagePartCount = Math.floor(messageLengthWithTerminator / 160);

    if (messageLengthWithTerminator % 160 !== 0) {
      messagePartCount++;
    }

    return messagePartCount * 160;
  },

  getPlaintext: function() {
    if (!this.plaintext) {
      var messageBuffer = this.message.toArrayBuffer();
      this.plaintext = new Uint8Array(
        this.getPaddedMessageLength(messageBuffer.byteLength + 1) - 1
      );
      this.plaintext.set(new Uint8Array(messageBuffer));
      this.plaintext[messageBuffer.byteLength] = 0x80;
    }
    return this.plaintext;
  },

  doSendMessage: function(number, deviceIds, recurse) {
    var ciphers = {};
    var plaintext = this.getPlaintext();

    return Promise.all(
      deviceIds.map(
        function(deviceId) {
          var address = new libsignal.SignalProtocolAddress(number, deviceId);

          var ourNumber = textsecure.storage.user.getNumber();
          var options = {};

          // No limit on message keys if we're communicating with our other devices
          if (ourNumber === number) {
            options.messageKeysLimit = false;
          }

          var sessionCipher = new libsignal.SessionCipher(
            textsecure.storage.protocol,
            address,
            options
          );
          ciphers[address.getDeviceId()] = sessionCipher;
          return sessionCipher.encrypt(plaintext).then(function(ciphertext) {
            return {
              type: ciphertext.type,
              destinationDeviceId: address.getDeviceId(),
              destinationRegistrationId: ciphertext.registrationId,
              content: btoa(ciphertext.body),
            };
          });
        }.bind(this)
      )
    )
      .then(
        function(jsonData) {
          return this.transmitMessage(number, jsonData, this.timestamp).then(
            function() {
              this.successfulNumbers[this.successfulNumbers.length] = number;
              this.numberCompleted();
            }.bind(this)
          );
        }.bind(this)
      )
      .catch(
        function(error) {
          if (
            error instanceof Error &&
            error.name == 'HTTPError' &&
            (error.code == 410 || error.code == 409)
          ) {
            if (!recurse)
              return this.registerError(
                number,
                'Hit retry limit attempting to reload device list',
                error
              );

            var p;
            if (error.code == 409) {
              p = this.removeDeviceIdsForNumber(
                number,
                error.response.extraDevices
              );
            } else {
              p = Promise.all(
                error.response.staleDevices.map(function(deviceId) {
                  return ciphers[deviceId].closeOpenSessionForDevice();
                })
              );
            }

            return p.then(
              function() {
                var resetDevices =
                  error.code == 410
                    ? error.response.staleDevices
                    : error.response.missingDevices;
                return this.getKeysForNumber(number, resetDevices).then(
                  this.reloadDevicesAndSend(number, error.code == 409)
                );
              }.bind(this)
            );
          } else if (error.message === 'Identity key changed') {
            error.timestamp = this.timestamp;
            error.originalMessage = this.message.toArrayBuffer();
            console.log(
              'Got "key changed" error from encrypt - no identityKey for application layer',
              number,
              deviceIds
            );
            throw error;
          } else {
            this.registerError(
              number,
              'Failed to create or send message',
              error
            );
          }
        }.bind(this)
      );
  },

  getStaleDeviceIdsForNumber: function(number) {
    return textsecure.storage.protocol
      .getDeviceIds(number)
      .then(function(deviceIds) {
        if (deviceIds.length === 0) {
          return [1];
        }
        var updateDevices = [];
        return Promise.all(
          deviceIds.map(function(deviceId) {
            var address = new libsignal.SignalProtocolAddress(number, deviceId);
            var sessionCipher = new libsignal.SessionCipher(
              textsecure.storage.protocol,
              address
            );
            return sessionCipher.hasOpenSession().then(function(hasSession) {
              if (!hasSession) {
                updateDevices.push(deviceId);
              }
            });
          })
        ).then(function() {
          return updateDevices;
        });
      });
  },

  removeDeviceIdsForNumber: function(number, deviceIdsToRemove) {
    var promise = Promise.resolve();
    for (var j in deviceIdsToRemove) {
      promise = promise.then(function() {
        var encodedNumber = number + '.' + deviceIdsToRemove[j];
        return textsecure.storage.protocol.removeSession(encodedNumber);
      });
    }
    return promise;
  },

  sendToNumber: function(number) {
    return this.getStaleDeviceIdsForNumber(number).then(
      function(updateDevices) {
        return this.getKeysForNumber(number, updateDevices)
          .then(this.reloadDevicesAndSend(number, true))
          .catch(
            function(error) {
              if (error.message === 'Identity key changed') {
                error = new textsecure.OutgoingIdentityKeyError(
                  number,
                  error.originalMessage,
                  error.timestamp,
                  error.identityKey
                );
                this.registerError(number, 'Identity key changed', error);
              } else {
                this.registerError(
                  number,
                  'Failed to retrieve new device keys for number ' + number,
                  error
                );
              }
            }.bind(this)
          );
      }.bind(this)
    );
  },
};