Encrypt rooms' last messages

MatrixSDK/Data/MXRoomLastMessage.h

@@ -69,6 +69,15 @@ FOUNDATION_EXPORT NSString *const MXRoomLastMessageDataType;
 
 - (instancetype)initWithEvent:(MXEvent *)event;
 
+/**
+ Returns an archived (possibly encrypted) version of MXRoomLastMessage sensible data.
+ These include:
+ - `text`
+ - `attributedText`
+ - `others`
+ */
+- (nullable NSData*)sensitiveData;
+
 #pragma mark - CoreData Model
 
 - (instancetype)initWithManagedObject:(MXRoomLastMessageMO *)model;

MatrixSDK/Data/MXRoomLastMessage.m

@@ -23,6 +23,7 @@
 
 #import <Security/Security.h>
 #import <CommonCrypto/CommonCryptor.h>
+#import <Foundation/Foundation.h>
 
 NSString *const MXRoomLastMessageDataType = @"org.matrix.sdk.keychain.MXRoomLastMessage";
 
@@ -58,6 +59,22 @@ - (instancetype)initWithEvent:(MXEvent *)event
     return self;
 }
 
+- (nullable NSData*)sensitiveData;
+{
+    NSData* archived = [NSKeyedArchiver archivedDataWithRootObject:[self sensitiveDataDictionary]
+                                             requiringSecureCoding:NO
+                                                             error:nil];
+
+    if (archived && self.isEncrypted)
+    {
+        return [self encrypt:archived];
+    }
+    else
+    {
+        return archived;
+    }
+}
+
 - (NSComparisonResult)compareOriginServerTs:(MXRoomLastMessage *)otherMessage
 {
     NSComparisonResult result = NSOrderedAscending;
@@ -87,16 +104,39 @@ - (instancetype)initWithManagedObject:(MXRoomLastMessageMO *)model
         _originServerTs = model.s_originServerTs;
         _isEncrypted = model.s_isEncrypted;
         _sender = model.s_sender;
-        _text = model.s_text;
-        if (model.s_attributedText)
+
+        NSData* archivedSensitiveData;
+        if (model.s_sensitiveData && model.s_isEncrypted)
         {
-            _attributedText = [NSKeyedUnarchiver unarchiveObjectWithData:model.s_attributedText];
+            archivedSensitiveData = [self decrypt:model.s_sensitiveData];
         }
-        if (model.s_others)
+        else
         {
-            _others = [NSKeyedUnarchiver unarchiveObjectWithData:model.s_others];
+            archivedSensitiveData = model.s_sensitiveData;
+        }
+
+        if (archivedSensitiveData)
+        {
+            NSDictionary* sensitiveDataDictionary = [NSKeyedUnarchiver unarchiveObjectWithData:archivedSensitiveData];
+
+            _text = sensitiveDataDictionary[kCodingKeyText];
+            _attributedText = sensitiveDataDictionary[kCodingKeyAttributedText];
+            _others = sensitiveDataDictionary[kCodingKeyOthers];
+        }
+        else // fallback logic for old database versions
+        {
+            _text = model.s_text;
+
+            if (model.s_attributedText) {
+                _attributedText = [NSKeyedUnarchiver unarchiveObjectWithData:model.s_attributedText];
+            }
+
+            if (model.s_others) {
+                _others = [NSKeyedUnarchiver unarchiveObjectWithData:model.s_others];
+            }
         }
     }
+
     return self;
 }
 
@@ -142,20 +182,7 @@ - (void)encodeWithCoder:(NSCoder *)coder
     [coder encodeObject:_sender forKey:kCodingKeySender];
 
     // Build last message sensitive data
-    NSMutableDictionary *lastMessageDictionary = [NSMutableDictionary dictionary];
-    if (_text)
-    {
-        lastMessageDictionary[kCodingKeyText] = _text;
-    }
-    if (_attributedText)
-    {
-        lastMessageDictionary[kCodingKeyAttributedText] = _attributedText;
-    }
-    if (_others)
-    {
-        lastMessageDictionary[kCodingKeyOthers] = _others;
-    }
-
+    NSDictionary *lastMessageDictionary = [self sensitiveDataDictionary];
     // And encrypt it if necessary
     if (_isEncrypted)
     {
@@ -173,6 +200,26 @@ - (void)encodeWithCoder:(NSCoder *)coder
     }
 }
 
+- (NSDictionary*)sensitiveDataDictionary
+{
+    NSMutableDictionary *lastMessageDictionary = [NSMutableDictionary dictionary];
+
+    if (_text)
+    {
+        lastMessageDictionary[kCodingKeyText] = _text;
+    }
+    if (_attributedText)
+    {
+        lastMessageDictionary[kCodingKeyAttributedText] = _attributedText;
+    }
+    if (_others)
+    {
+        lastMessageDictionary[kCodingKeyOthers] = _others;
+    }
+
+    return  lastMessageDictionary;
+}
+
 #pragma mark - Data encryption
 
 /**

MatrixSDK/Data/RoomSummaryStore/CoreData/MXCoreDataRoomSummaryStore.xcdatamodeld/MXRoomSummaryCoreDataStore2.xcdatamodel/contents

@@ -1,12 +1,13 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="20086" systemVersion="21E258" minimumToolsVersion="Automatic" sourceLanguage="Swift" userDefinedModelVersionIdentifier="">
+<model type="com.apple.IDECoreDataModeler.DataModel" documentVersion="1.0" lastSavedToolsVersion="21513" systemVersion="22C65" minimumToolsVersion="Automatic" sourceLanguage="Swift" userDefinedModelVersionIdentifier="">
     <entity name="MXRoomLastMessage" representedClassName="MXRoomLastMessageMO" syncable="YES">
         <attribute name="s_attributedText" optional="YES" attributeType="Binary" valueTransformerName=""/>
         <attribute name="s_eventId" attributeType="String"/>
         <attribute name="s_isEncrypted" attributeType="Boolean" defaultValueString="NO" usesScalarValueType="YES"/>
         <attribute name="s_originServerTs" attributeType="Integer 64" defaultValueString="0" usesScalarValueType="YES"/>
         <attribute name="s_others" optional="YES" attributeType="Binary"/>
         <attribute name="s_sender" attributeType="String"/>
+        <attribute name="s_sensitiveData" optional="YES" attributeType="Binary"/>
         <attribute name="s_text" optional="YES" attributeType="String"/>
         <relationship name="s_ofRoom" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="MXRoomSummary" inverseName="s_lastMessage" inverseEntity="MXRoomSummary"/>
     </entity>
@@ -62,10 +63,4 @@
         <attribute name="s_usersCount" attributeType="Integer 32" defaultValueString="0" usesScalarValueType="YES"/>
         <relationship name="s_ofRoom" optional="YES" maxCount="1" deletionRule="Nullify" destinationEntity="MXRoomSummary" inverseName="s_trust" inverseEntity="MXRoomSummary"/>
     </entity>
-    <elements>
-        <element name="MXRoomLastMessage" positionX="117" positionY="90" width="128" height="149"/>
-        <element name="MXRoomMembersCount" positionX="297.1484375" positionY="-66.14453125" width="128" height="89"/>
-        <element name="MXRoomSummary" positionX="-63" positionY="-18" width="128" height="509"/>
-        <element name="MXUsersTrustLevelSummary" positionX="236.4921875" positionY="519.4296875" width="128" height="104"/>
-    </elements>
 </model>

MatrixSDK/Data/RoomSummaryStore/CoreData/Models/MXRoomLastMessageMO.swift

@@ -28,10 +28,17 @@ public class MXRoomLastMessageMO: NSManagedObject {
     @NSManaged public var s_originServerTs: UInt64
     @NSManaged public var s_isEncrypted: Bool
     @NSManaged public var s_sender: String
+    @NSManaged public var s_sensitiveData: Data?
+
+    @available(*, deprecated, message: "Store sensitive information on s_sensitiveData instead")
     @NSManaged public var s_text: String?
-    @NSManaged public var s_attributedText: Data?
+
+    @available(*, deprecated, message: "Store sensitive information on s_sensitiveData instead")
     @NSManaged public var s_others: Data?
 
+    @available(*, deprecated, message: "Store sensitive information on s_sensitiveData instead")
+    @NSManaged public var s_attributedText: Data?
+
     @discardableResult
     internal static func insert(roomLastMessage lastMessage: MXRoomLastMessage,
                                 into moc: NSManagedObjectContext) -> MXRoomLastMessageMO {
@@ -47,19 +54,11 @@ public class MXRoomLastMessageMO: NSManagedObject {
         s_originServerTs = lastMessage.originServerTs
         s_isEncrypted = lastMessage.isEncrypted
         s_sender = lastMessage.sender
-        s_text = lastMessage.text
-
-        if let attributedText = lastMessage.attributedText {
-            s_attributedText = NSKeyedArchiver.archivedData(withRootObject: attributedText)
-        } else {
-            s_attributedText = nil
-        }
+        s_sensitiveData = lastMessage.sensitiveData()
 
-        if let others = lastMessage.others {
-            s_others = NSKeyedArchiver.archivedData(withRootObject: others)
-        } else {
-            s_others = nil
-        }
+        // Cleaning up unencrypted data in the old database versions. In the future these properties should be deleted from Core Data.
+        s_text = nil;
+        s_others = nil;
+        s_attributedText = nil;
     }
-
 }

changelog.d/pr-1718.change

@@ -0,0 +1 @@
+Encryption: add encryption to rooms' last messages.