MXCrypto: Use the last olm session that got a message

CHANGES.rst

@@ -1,13 +1,14 @@
 Changes in Matrix iOS SDK in 0.12.1 (2012-12-xx)
 ===============================================
 
+Improvements:
+* MXCrypto: Use the last olm session that got a message (vector-im/riot-ios/issues/2128).
+* MXScanManager: Support the encrypted body (the request body is now encrypted by default using the server public key).
+* MXMediaManager: Support the encrypted body.
+
 Bug Fix:
  * MXCryptoStore: Stop duplicating devices in the store (vector-im/riot-ios/issues/2132).
 
-Improvements:
- * MXScanManager: Support the encrypted body (the request body is now encrypted by default using the server public key).
- * MXMediaManager: Support the encrypted body.
-
 Changes in Matrix iOS SDK in 0.12.0 (2018-12-06)
 ===============================================
 

MatrixSDK.xcodeproj/project.pbxproj

@@ -240,6 +240,8 @@
 		32E226A61D06AC9F00E6CA54 /* MXPeekingRoom.h in Headers */ = {isa = PBXBuildFile; fileRef = 32E226A41D06AC9F00E6CA54 /* MXPeekingRoom.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		32E226A71D06AC9F00E6CA54 /* MXPeekingRoom.m in Sources */ = {isa = PBXBuildFile; fileRef = 32E226A51D06AC9F00E6CA54 /* MXPeekingRoom.m */; };
 		32E226A91D081CE200E6CA54 /* MXPeekingRoomTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 32E226A81D081CE200E6CA54 /* MXPeekingRoomTests.m */; };
+		32E402B921C957D2004E87A6 /* MXOlmSession.h in Headers */ = {isa = PBXBuildFile; fileRef = 32E402B721C957D2004E87A6 /* MXOlmSession.h */; };
+		32E402BA21C957D2004E87A6 /* MXOlmSession.m in Sources */ = {isa = PBXBuildFile; fileRef = 32E402B821C957D2004E87A6 /* MXOlmSession.m */; };
 		32F634AB1FC5E3480054EF49 /* MXEventDecryptionResult.h in Headers */ = {isa = PBXBuildFile; fileRef = 32F634A91FC5E3470054EF49 /* MXEventDecryptionResult.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		32F634AC1FC5E3480054EF49 /* MXEventDecryptionResult.m in Sources */ = {isa = PBXBuildFile; fileRef = 32F634AA1FC5E3470054EF49 /* MXEventDecryptionResult.m */; };
 		32F945F51FAB83D900622468 /* MXIncomingRoomKeyRequestCancellation.m in Sources */ = {isa = PBXBuildFile; fileRef = 32F945F11FAB83D800622468 /* MXIncomingRoomKeyRequestCancellation.m */; };
@@ -614,6 +616,8 @@
 		32E226A41D06AC9F00E6CA54 /* MXPeekingRoom.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MXPeekingRoom.h; sourceTree = "<group>"; };
 		32E226A51D06AC9F00E6CA54 /* MXPeekingRoom.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MXPeekingRoom.m; sourceTree = "<group>"; };
 		32E226A81D081CE200E6CA54 /* MXPeekingRoomTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MXPeekingRoomTests.m; sourceTree = "<group>"; };
+		32E402B721C957D2004E87A6 /* MXOlmSession.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MXOlmSession.h; sourceTree = "<group>"; };
+		32E402B821C957D2004E87A6 /* MXOlmSession.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MXOlmSession.m; sourceTree = "<group>"; };
 		32F1FE9AF82A426C2EAED587 /* Pods-MatrixSDK.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-MatrixSDK.release.xcconfig"; path = "Pods/Target Support Files/Pods-MatrixSDK/Pods-MatrixSDK.release.xcconfig"; sourceTree = "<group>"; };
 		32F634A91FC5E3470054EF49 /* MXEventDecryptionResult.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MXEventDecryptionResult.h; sourceTree = "<group>"; };
 		32F634AA1FC5E3470054EF49 /* MXEventDecryptionResult.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = MXEventDecryptionResult.m; sourceTree = "<group>"; };
@@ -1131,6 +1135,8 @@
 				32A151451DAF7C0C00400192 /* MXUsersDevicesMap.m */,
 				324BE46A1E422766008D99D4 /* MXMegolmSessionData.h */,
 				324BE46B1E422766008D99D4 /* MXMegolmSessionData.m */,
+				32E402B721C957D2004E87A6 /* MXOlmSession.h */,
+				32E402B821C957D2004E87A6 /* MXOlmSession.m */,
 			);
 			path = Data;
 			sourceTree = "<group>";
@@ -1593,6 +1599,7 @@
 				323F3F9420D3F0C700D26D6A /* MXRoomEventFilter.h in Headers */,
 				32A9E8251EF4026E0081358A /* MXUIKitBackgroundModeHandler.h in Headers */,
 				325D1C261DFECE0D0070B8BF /* MXCrypto_Private.h in Headers */,
+				32E402B921C957D2004E87A6 /* MXOlmSession.h in Headers */,
 				B146D4D621A5A44E00D8C2C6 /* MXScanRealmInMemoryProvider.h in Headers */,
 				B17285792100C8EA0052C51E /* MXSendReplyEventStringsLocalizable.h in Headers */,
 				32A151521DAF8A7200400192 /* MXQueuedEncryption.h in Headers */,
@@ -1866,6 +1873,7 @@
 				32D776821A27877300FC4AA2 /* MXMemoryRoomStore.m in Sources */,
 				3293C701214BBA4F009B3DDB /* MXPeekingRoomSummary.m in Sources */,
 				C602B58C1F2268F700B67D87 /* MXRoom.swift in Sources */,
+				32E402BA21C957D2004E87A6 /* MXOlmSession.m in Sources */,
 				32A151271DABB0CB00400192 /* MXMegolmDecryption.m in Sources */,
 				C6D5D60E1E4FBD2900706C0F /* MXSession.swift in Sources */,
 				320DFDE319DD99B60068622A /* MXError.m in Sources */,

MatrixSDK/Crypto/Data/MXOlmSession.h

@@ -0,0 +1,56 @@
+/*
+ Copyright 2018 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "MXSDKOptions.h"
+
+#ifdef MX_CRYPTO
+
+#import <OLMKit/OLMKit.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ The 'MXOlmSession' class adds additional information to an OLMSession object from OLMKit.
+ */
+@interface MXOlmSession : NSObject
+
+
+- (instancetype)initWithOlmSession:(OLMSession*)session;
+
+/**
+ The associated olm session.
+ */
+@property (nonatomic, readonly) OLMSession *session;
+
+/**
+ Timestamp at which the session last received a message.
+ */
+@property (nonatomic) NSTimeInterval lastReceivedMessageTs;
+
+
+/**
+ Notify this model that a message has been received on this olm session
+ so that it updates `lastReceivedMessageTs`
+ */
+- (void)didReceiveMessage;
+
+@end
+
+NS_ASSUME_NONNULL_END
+
+#endif

MatrixSDK/Crypto/Data/MXOlmSession.m

@@ -0,0 +1,37 @@
+/*
+ Copyright 2018 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import "MXOlmSession.h"
+
+@implementation MXOlmSession
+
+- (instancetype)initWithOlmSession:(OLMSession *)session
+{
+    self = [super init];
+    if (self)
+    {
+        _session = session;
+        _lastReceivedMessageTs = 0;
+    }
+    return self;
+}
+
+- (void)didReceiveMessage
+{
+    _lastReceivedMessageTs = [[NSDate date] timeIntervalSince1970];
+}
+
+@end

MatrixSDK/Crypto/Data/Store/MXCryptoStore.h

@@ -24,6 +24,7 @@
 #import "MXJSONModels.h"
 
 #import <OLMKit/OLMKit.h>
+#import "MXOlmSession.h"
 #import "MXOlmInboundGroupSession.h"
 #import "MXDeviceInfo.h"
 #import "MXOutgoingRoomKeyRequest.h"
@@ -188,16 +189,26 @@
  @param deviceKey the public key of the other device.
  @param session the end-to-end session.
  */
-- (void)storeSession:(OLMSession*)session forDevice:(NSString*)deviceKey;
+- (void)storeSession:(MXOlmSession*)session forDevice:(NSString*)deviceKey;
 
 /**
- Retrieve the end-to-end sessions between the logged-in user and another
+ Retrieve an end-to-end session between the logged-in user and another
  device.
 
  @param deviceKey the public key of the other device.
- @return {object} A map from sessionId to Base64 end-to-end session.
+ @return a array of end-to-end sessions sorted by the last updated first.
  */
-- (NSDictionary<NSString*, OLMSession*>*)sessionsWithDevice:(NSString*)deviceKey;
+- (MXOlmSession*)sessionWithDevice:(NSString*)deviceKey andSessionId:(NSString*)sessionId;
+
+/**
+ Retrieve all end-to-end sessions between the logged-in user and another
+ device sorted by `lastReceivedMessageTs`, the most recent(higest value) first.
+
+ @param deviceKey the public key of the other device.
+ @return a array of end-to-end sessions.
+ */
+- (NSArray<MXOlmSession*>*)sessionsWithDevice:(NSString*)deviceKey;
+
 
 /**
  Store an inbound group session.

MatrixSDK/Crypto/Data/Store/MXRealmCryptoStore/MXRealmCryptoStore.m

@@ -23,7 +23,7 @@
 #import "MXSession.h"
 #import "MXTools.h"
 
-NSUInteger const kMXRealmCryptoStoreVersion = 8;
+NSUInteger const kMXRealmCryptoStoreVersion = 9;
 
 static NSString *const kMXRealmCryptoStoreFolder = @"MXRealmCryptoStore";
 
@@ -84,6 +84,7 @@ + (NSString *)primaryKey
 @interface MXRealmOlmSession : RLMObject
 @property NSString *sessionId;
 @property NSString *deviceKey;
+@property NSTimeInterval lastReceivedMessageTs;
 @property NSData *olmSessionData;
 @end
 
@@ -599,48 +600,77 @@ - (MXRealmRoomAlgorithm *)realmRoomAlgorithmForRoom:(NSString*)roomId inRealm:(R
 }
 
 
-- (void)storeSession:(OLMSession*)session forDevice:(NSString*)deviceKey
+- (void)storeSession:(MXOlmSession*)session forDevice:(NSString*)deviceKey
 {
     BOOL isNew = NO;
     NSDate *startDate = [NSDate date];
 
     RLMRealm *realm = self.realm;
     [realm transactionWithBlock:^{
 
-        MXRealmOlmSession *realmOlmSession = [MXRealmOlmSession objectsInRealm:realm where:@"sessionId = %@ AND deviceKey = %@", session.sessionIdentifier, deviceKey].firstObject;
+        MXRealmOlmSession *realmOlmSession = [MXRealmOlmSession objectsInRealm:realm where:@"sessionId = %@ AND deviceKey = %@", session.session.sessionIdentifier, deviceKey].firstObject;
         if (realmOlmSession)
         {
             // Update the existing one
-            realmOlmSession.olmSessionData = [NSKeyedArchiver archivedDataWithRootObject:session];
+            realmOlmSession.olmSessionData = [NSKeyedArchiver archivedDataWithRootObject:session.session];
         }
         else
         {
             // Create it
             realmOlmSession = [[MXRealmOlmSession alloc] initWithValue:@{
-                                                                         @"sessionId": session.sessionIdentifier,
+                                                                         @"sessionId": session.session.sessionIdentifier,
                                                                          @"deviceKey": deviceKey,
-                                                                         @"olmSessionData": [NSKeyedArchiver archivedDataWithRootObject:session]
+                                                                         @"olmSessionData": [NSKeyedArchiver archivedDataWithRootObject:session.session]
                                                                          }];
+            realmOlmSession.lastReceivedMessageTs = session.lastReceivedMessageTs;
+
             [realm addObject:realmOlmSession];
         }
     }];
 
     NSLog(@"[MXRealmCryptoStore] storeSession (%@) in %.0fms", (isNew?@"NEW":@"UPDATE"), [[NSDate date] timeIntervalSinceDate:startDate] * 1000);
 }
 
-- (NSDictionary<NSString*, OLMSession*>*)sessionsWithDevice:(NSString*)deviceKey
+- (MXOlmSession*)sessionWithDevice:(NSString*)deviceKey andSessionId:(NSString*)sessionId
 {
-    NSMutableDictionary<NSString*, OLMSession*> *sessionsWithDevice;
+    MXRealmOlmSession *realmOlmSession = [MXRealmOlmSession objectsInRealm:self.realm
+                                                                      where:@"sessionId = %@ AND deviceKey = %@", sessionId, deviceKey].firstObject;
+
+    MXOlmSession *mxOlmSession;
+    if (realmOlmSession.olmSessionData)
+    {
+        OLMSession *olmSession = [NSKeyedUnarchiver unarchiveObjectWithData:realmOlmSession.olmSessionData];
 
-    RLMResults<MXRealmOlmSession *> *realmOlmSessions = [MXRealmOlmSession objectsInRealm:self.realm where:@"deviceKey = %@", deviceKey];
+        mxOlmSession = [[MXOlmSession alloc] initWithOlmSession:olmSession];
+        mxOlmSession.lastReceivedMessageTs = realmOlmSession.lastReceivedMessageTs;
+    }
+
+    return mxOlmSession;
+}
+
+- (NSArray<MXOlmSession*>*)sessionsWithDevice:(NSString*)deviceKey;
+{
+    NSMutableArray<MXOlmSession*> *sessionsWithDevice;
+
+    RLMResults<MXRealmOlmSession *> *realmOlmSessions = [[MXRealmOlmSession objectsInRealm:self.realm
+                                                                                     where:@"deviceKey = %@", deviceKey]
+                                                         sortedResultsUsingKeyPath:@"lastReceivedMessageTs" ascending:NO];
     for (MXRealmOlmSession *realmOlmSession in realmOlmSessions)
     {
         if (!sessionsWithDevice)
         {
-            sessionsWithDevice = [NSMutableDictionary dictionary];
+            sessionsWithDevice = [NSMutableArray array];
         }
 
-        sessionsWithDevice[realmOlmSession.sessionId] = [NSKeyedUnarchiver unarchiveObjectWithData:realmOlmSession.olmSessionData];
+        if (realmOlmSession.olmSessionData)
+        {
+            OLMSession *olmSession = [NSKeyedUnarchiver unarchiveObjectWithData:realmOlmSession.olmSessionData];
+
+            MXOlmSession *mxOlmSession = [[MXOlmSession alloc] initWithOlmSession:olmSession];
+            mxOlmSession.lastReceivedMessageTs = realmOlmSession.lastReceivedMessageTs;
+
+            [sessionsWithDevice addObject:mxOlmSession];
+        }
     }
 
     return sessionsWithDevice;
@@ -1189,6 +1219,23 @@ + (RLMRealm*)realmForUser:(NSString*)userId
                     // make queries. So, the cleaning will be done afterwards.
                     cleanDuplicatedDevices = YES;
                 }
+
+                case 8:
+                {
+                    // MXRealmOlmSession.lastReceivedMessageTs has been added to implement:
+                    // Use the last olm session that got a message
+                    // https://github.com/vector-im/riot-ios/issues/2128
+
+                    NSLog(@"[MXRealmCryptoStore] Migration from schema #8 -> #9");
+
+                    NSLog(@"    Add lastReceivedMessageTs = 0 to all MXRealmOlmSession objects");
+                    [migration enumerateObjects:MXRealmOlmSession.className block:^(RLMObject *oldObject, RLMObject *newObject) {
+
+                        newObject[@"lastReceivedMessageTs"] = 0;
+                    }];
+
+                    NSLog(@"[MXRealmCryptoStore] Migration from schema #8 -> #9 completed");
+                }
             }
         }
     };