Merge pull request #1467 from matrix-org/andy/build_flag

Shared history flag in crypto module
matrix-org · May 19, 2022 · 03a153e · 03a153e
2 parents 6cb7100 + a1c667a
commit 03a153e
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Showing 3 changed files with 86 additions and 2 deletions.
diff --git a/MatrixSDK/Crypto/MXCrypto.m b/MatrixSDK/Crypto/MXCrypto.m
@@ -1897,6 +1897,11 @@ - (BOOL)isRoomEncrypted:(NSString *)roomId
 
 - (BOOL)isRoomSharingHistory:(NSString *)roomId
 {
+    if (!MXSDKOptions.sharedInstance.enableRoomSharedHistoryOnInvite)
+    {
+        return NO;
+    }
+
     MXRoom *room = [self.mxSession roomWithRoomId:roomId];
     MXRoomHistoryVisibility visibility = room.summary.historyVisibility;
     return [visibility isEqualToString:kMXRoomHistoryVisibilityWorldReadable] || [visibility isEqualToString:kMXRoomHistoryVisibilityShared];

diff --git a/MatrixSDKTests/Crypto/Algorithms/Megolm/MXMegolmEncryptionTests.swift b/MatrixSDKTests/Crypto/Algorithms/Megolm/MXMegolmEncryptionTests.swift
@@ -49,7 +49,8 @@ class MXMegolmEncryptionTests: XCTestCase {
         return store?.inboundGroupSessions().last?.sharedHistory == true
     }
 
-    func testResetsSessionIfRoomVisibilityChanges() {
+    func test_resetsSession_ifRoomVisibilityChanges() {
+        MXSDKOptions.sharedInstance().enableRoomSharedHistoryOnInvite = true
 
         // The following tests that oubound session Id (and therefore the related inbound session Id)
         // is reset whenever the room's history visibility changes from shared to not shared.
@@ -122,4 +123,78 @@ class MXMegolmEncryptionTests: XCTestCase {
             }
         }
     }
+
+    func test_doesNotResetsSession_ifRoomVisibilityChanges_andFeatureDisabled() {
+        MXSDKOptions.sharedInstance().enableRoomSharedHistoryOnInvite = false
+
+        // The following tests that if the feature is disabled, then outbound session Id
+        // is not reset when room visibility changes
+        e2eData.doE2ETestWithAlice(inARoom: self) { session, roomId, expectation in
+
+            let room = session?.room(withRoomId: roomId)
+
+            // 1st set of messages
+            room?.sendTextMessages(messages: ["Hi", "Hello"]) { _ in
+
+                // After first few messages we only expect one inbound and one outbound session
+                let sessionIds1 = self.storedSessionIds(in: session)
+                XCTAssertEqual(sessionIds1.outbound.count, 1)
+                XCTAssertEqual(sessionIds1.inbound.count, 1)
+                XCTAssertEqual(sessionIds1.inbound, sessionIds1.outbound)
+                XCTAssertFalse(self.isSharedHistoryInLastSession(for: session))
+
+                // 2nd set of messages
+                room?.sendTextMessages(messages: ["Hi", "Hello"]) { _ in
+
+                    // After second batch of messages nothing has changed that would require resetting
+                    // of sessions, therefore sessionIds are unchanged
+                    let sessionIds2 = self.storedSessionIds(in: session)
+                    XCTAssertEqual(sessionIds2, sessionIds1)
+                    XCTAssertFalse(self.isSharedHistoryInLastSession(for: session))
+
+                    // Changing room visibility from shared by default to more restrictive will not reset session keys
+                    room?.setHistoryVisibility(.joined) { _ in
+
+                        // 3rd set of messages
+                        room?.sendTextMessages(messages: ["Hi", "Hello"]) { _ in
+
+                            // Sessions are identical as before
+                            let sessionIds3 = self.storedSessionIds(in: session)
+                            XCTAssertEqual(sessionIds3.outbound.count, 1)
+                            XCTAssertEqual(sessionIds3.outbound, sessionIds2.outbound)
+                            XCTAssertEqual(sessionIds3.inbound.count, 1)
+                            XCTAssertEqual(sessionIds3.inbound, sessionIds1.outbound)
+                            XCTAssertFalse(self.isSharedHistoryInLastSession(for: session))
+
+                            // 4th set of messages
+                            room?.sendTextMessages(messages: ["Hi", "Hello"]) { _ in
+                                // After fourth batch of messages nothing has changed that would require resetting
+                                // of sessions, therefore sessionIds are unchanged
+                                let sessionIds4 = self.storedSessionIds(in: session)
+                                XCTAssertEqual(sessionIds4, sessionIds3)
+                                XCTAssertFalse(self.isSharedHistoryInLastSession(for: session))
+
+                                // Final visibility change back to shared will still not reset sessions
+                                room?.setHistoryVisibility(.worldReadable) { _ in
+                                    room?.sendTextMessages(messages: ["Hi", "Hello"]) { _ in
+
+                                        // Sessions are still identical as before
+                                        let sessionIds5 = self.storedSessionIds(in: session)
+                                        XCTAssertEqual(sessionIds5.outbound.count, 1)
+                                        XCTAssertEqual(sessionIds5.outbound, sessionIds4.outbound)
+                                        XCTAssertEqual(sessionIds5.inbound.count, 1)
+                                        XCTAssertEqual(sessionIds5.inbound, sessionIds1.outbound)
+                                        XCTAssertFalse(self.isSharedHistoryInLastSession(for: session))
+
+                                        session?.close()
+                                        expectation?.fulfill()
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
 }
diff --git a/MatrixSDKTests/MXCryptoTests.m b/MatrixSDKTests/MXCryptoTests.m
@@ -3235,7 +3235,11 @@ - (void)testIsRoomSharingHistory
             @[kMXRoomHistoryVisibilityWorldReadable, @(YES)]
         ];
 
-        // Visibility is set to shared by default
+        // Visibility is set to not shared by default
+        XCTAssertFalse([session.crypto isRoomSharingHistory:roomId]);
+
+        // But can be enabled with a build flag
+        MXSDKOptions.sharedInstance.enableRoomSharedHistoryOnInvite = YES;
         XCTAssertTrue([session.crypto isRoomSharingHistory:roomId]);
 
         MXRoom *room = [session roomWithRoomId:roomId];