Megolm: don't dereference nullable object

It is possible for `room` to be null when passed to
MegolmEncryption.encryptMessage; we need to avoid dereferencing it. Instead,
make sure that the EncryptionAlgorithm knows about the roomId it is targeting,
and use that.

Replace the increasingly-long argument list on the EncryptionAlgorithm
constructor with a params list, and update DecryptionAlgorithm to match.

lib/crypto-algorithms/base.js

@@ -44,14 +44,17 @@ module.exports.DECRYPTION_CLASSES = {};
  *
  * @constructor
  *
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
+ * @param {object} params parameters
+ * @param {string} params.deviceId The identifier for this device.
+ * @param {module:crypto} params.crypto crypto core
+ * @param {module:OlmDevice} params.olmDevice olm.js wrapper
+ * @param {string} params.roomId  The ID of the room we will be sending to
  */
-module.exports.EncryptionAlgorithm = function(deviceId, crypto, olmDevice) {
-    this._deviceId = deviceId;
-    this._crypto = crypto;
-    this._olmDevice = olmDevice;
+module.exports.EncryptionAlgorithm = function(params) {
+    this._deviceId = params.deviceId;
+    this._crypto = params.crypto;
+    this._olmDevice = params.olmDevice;
+    this._roomId = params.roomId;
 };
 
 /**
@@ -70,7 +73,7 @@ module.exports.EncryptionAlgorithm = function(deviceId, crypto, olmDevice) {
  * @method module:crypto-algorithms/base.EncryptionAlgorithm#encryptMessage
  * @abstract
  *
- * @param {module:models/room} room
+ * @param {module:models/room?} room
  * @param {string} eventType
  * @param {object} plaintext event content
  *
@@ -82,14 +85,11 @@ module.exports.EncryptionAlgorithm = function(deviceId, crypto, olmDevice) {
  * base type for decryption implementations
  *
  * @constructor
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
+ * @param {object} params parameters
+ * @param {module:OlmDevice} params.olmDevice olm.js wrapper
  */
-module.exports.DecryptionAlgorithm = function(deviceId, crypto, olmDevice) {
-    this._deviceId = deviceId;
-    this._crypto = crypto;
-    this._olmDevice = olmDevice;
+module.exports.DecryptionAlgorithm = function(params) {
+    this._olmDevice = params.olmDevice;
 };
 
 /**

lib/crypto-algorithms/megolm.js

@@ -18,7 +18,7 @@ limitations under the License.
 /**
  * Defines m.olm encryption/decryption
  *
- * @module crypto-algorithms/olm
+ * @module crypto-algorithms/megolm
  */
 
 var q = require("q");
@@ -34,13 +34,11 @@ var MEGOLM_ALGORITHM = "m.megolm.v1.aes-sha2";
  * @constructor
  * @extends {module:crypto-algorithms/base.EncryptionAlgorithm}
  *
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
- *
+ * @param {object} params parameters, as per
+ *     {@link module:crypto-algorithms/base.EncryptionAlgorithm}
  */
-function MegolmEncryption(deviceId, crypto, olmDevice) {
-    base.EncryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+function MegolmEncryption(params) {
+    base.EncryptionAlgorithm.call(this, params);
     this._outboundSessionId = null;
 }
 utils.inherits(MegolmEncryption, base.EncryptionAlgorithm);
@@ -58,9 +56,8 @@ MegolmEncryption.prototype.initRoomEncryption = function(roomMembers) {
 
 /**
  * @private
- * @param {string} roomId
  */
-MegolmEncryption.prototype._ensureOutboundSession = function(roomId) {
+MegolmEncryption.prototype._ensureOutboundSession = function() {
     if (this._outboundSessionId) {
         return;
     }
@@ -75,14 +72,14 @@ MegolmEncryption.prototype._ensureOutboundSession = function(roomId) {
         'Created outbound session. Add with window.mxMatrixClientPeg.' +
             'matrixClient._crypto._olmDevice.addInboundGroupSession("' +
             [
-                roomId, this._olmDevice.deviceCurve25519Key, session_id,
+                this._roomId, this._olmDevice.deviceCurve25519Key, session_id,
                 key.key, key.chain_index
             ].join('", "') +
             '")'
     );
 
     this._olmDevice.addInboundGroupSession(
-        roomId, this._olmDevice.deviceCurve25519Key, session_id,
+        this._roomId, this._olmDevice.deviceCurve25519Key, session_id,
         key.key, key.chain_index
     );
 };
@@ -90,17 +87,17 @@ MegolmEncryption.prototype._ensureOutboundSession = function(roomId) {
 /**
  * @inheritdoc
  *
- * @param {module:models/room} room
+ * @param {module:models/room?} room
  * @param {string} eventType
  * @param {object} plaintext event content
  *
  * @return {object} new event body
  */
 MegolmEncryption.prototype.encryptMessage = function(room, eventType, content) {
-    this._ensureOutboundSession(room.roomId);
+    this._ensureOutboundSession();
 
     var payloadJson = {
-        room_id: room.roomId,
+        room_id: this._roomId,
         type: eventType,
         content: content
     };
@@ -126,13 +123,11 @@ MegolmEncryption.prototype.encryptMessage = function(room, eventType, content) {
  * @constructor
  * @extends {module:crypto-algorithms/base.DecryptionAlgorithm}
  *
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
- *
+ * @param {object} params parameters, as per
+ *     {@link module:crypto-algorithms/base.DecryptionAlgorithm}
  */
-function MegolmDecryption(deviceId, crypto, olmDevice) {
-    base.DecryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+function MegolmDecryption(params) {
+    base.DecryptionAlgorithm.call(this, params);
 }
 utils.inherits(MegolmDecryption, base.DecryptionAlgorithm);
 

lib/crypto-algorithms/olm.js

@@ -33,13 +33,11 @@ var OLM_ALGORITHM = "m.olm.v1.curve25519-aes-sha2";
  * @constructor
  * @extends {module:crypto-algorithms/base.EncryptionAlgorithm}
  *
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
- *
+ * @param {object} params parameters, as per
+ *     {@link module:crypto-algorithms/base.EncryptionAlgorithm}
  */
-function OlmEncryption(deviceId, crypto, olmDevice) {
-    base.EncryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+function OlmEncryption(params) {
+    base.EncryptionAlgorithm.call(this, params);
 }
 utils.inherits(OlmEncryption, base.EncryptionAlgorithm);
 
@@ -58,7 +56,7 @@ OlmEncryption.prototype.initRoomEncryption = function(roomMembers) {
 /**
  * @inheritdoc
  *
- * @param {module:models/room} room
+ * @param {module:models/room?} room
  * @param {string} eventType
  * @param {object} plaintext event content
  *
@@ -138,14 +136,11 @@ OlmEncryption.prototype.encryptMessage = function(room, eventType, content) {
  *
  * @constructor
  * @extends {module:crypto-algorithms/base.DecryptionAlgorithm}
- *
- * @param {string} deviceId The identifier for this device.
- * @param {module:crypto} crypto crypto core
- * @param {module:OlmDevice} olmDevice olm.js wrapper
- *
+ * @param {object} params parameters, as per
+ *     {@link module:crypto-algorithms/base.DecryptionAlgorithm}
  */
-function OlmDecryption(deviceId, crypto, olmDevice) {
-    base.DecryptionAlgorithm.call(this, deviceId, crypto, olmDevice);
+function OlmDecryption(params) {
+    base.DecryptionAlgorithm.call(this, params);
 }
 utils.inherits(OlmDecryption, base.DecryptionAlgorithm);