Properly handle too-large messages

1. Take note of any large messages.
2. If they are way too large, we just drop them on the floor.

// FREEBIE

Podfile.lock

@@ -125,7 +125,7 @@ EXTERNAL SOURCES:
     :branch: signal-master
     :git: https://github.com/WhisperSystems/JSQMessagesViewController.git
   SignalServiceKit:
-    :path: .
+    :path: "."
   SocketRocket:
     :git: https://github.com/facebook/SocketRocket.git
 

SignalServiceKit/Example/TSKitiOSTestApp/Podfile.lock

@@ -113,7 +113,7 @@ EXTERNAL SOURCES:
   AxolotlKit:
     :git: https://github.com/WhisperSystems/SignalProtocolKit.git
   SignalServiceKit:
-    :path: ../../../SignalServiceKit.podspec
+    :path: "../../../SignalServiceKit.podspec"
   SocketRocket:
     :git: https://github.com/facebook/SocketRocket.git
 

SignalServiceKit/src/Messages/OWSMessageReceiver.m

@@ -333,6 +333,20 @@ NSString *const OWSMessageProcessingJobFinderExtensionGroup = @"OWSMessageProces
 
 - (void)handleReceivedEnvelope:(OWSSignalServiceProtosEnvelope *)envelope
 {
+    // Drop any too-large messages on the floor. Well behaving clients should never send them.
+    NSUInteger kMaxEnvelopeByteCount = 250 * 1024;
+    if (envelope.serializedSize > kMaxEnvelopeByteCount) {
+        OWSProdError(@"message_receiver_error_oversize_message");
+        return;
+    }
+
+    // Take note of any messages larger than we expect, but still process them.
+    // This likely indicates a misbehaving sending client.
+    NSUInteger kLargeEnvelopeWarningByteCount = 25 * 1024;
+    if (envelope.serializedSize > kLargeEnvelopeWarningByteCount) {
+        OWSProdError(@"message_receiver_error_large_message");
+    }
+
     [self.processingQueue enqueueEnvelopeForProcessing:envelope];
     [self.processingQueue drainQueue];
 }

SignalServiceKit/src/Messages/TSMessagesManager.m

@@ -392,13 +392,6 @@ NS_ASSUME_NONNULL_BEGIN
                 return;
             }
 
-            NSUInteger kMaxEncryptedDataLength = 250 * 1024;
-            if (encryptedData.length > kMaxEncryptedDataLength) {
-                OWSProdError(@"message_manager_error_oversize_message");
-                completion(nil);
-                return;
-            }
-
             NSData *plaintextData;
 
             @try {