ChatHeads-Extensions

These tweaks are designed to be installed and communicate (via RocketBootstrap) with ChatHeads.

The goal of these tweaks is to provide communications between applications such as stock iOS Messages, Facebook Messenger, WhatsApp, etc. and ChatHeads. Information such as the message body, contact photo, contact name, and thread-id will allow ChatHeads to present a head for the corresponding application.

Dumping Headers

To dump headers for the desired client apps, install BFDecrypt from level3tjg.github.io. Open BFDecrypt's settings, enable the app(s) you would like to decrypt. Open the apps, let BFDecrypt do its thing. Then on your computer run nc xx.x.x.x 31336 > ~/Desktop/decrypted.ipa. This will transfer the IPA to your desktop.

Unzip the .ipa and find the executable(s) you would like to dump the headers for. Facebook was tricky as the main executable would not dump. This turned out to be the result of Messenger relying on shared frameworks containing the bulk of the code. Navigating to /Messenger/Frameworks/ will reveal the different frameworks. Inside each framework exists a different executable which I did manage to dump. (I have not included any .ipa's or headers due to legal reasons)

Once you find the executables, run class-dump on them

class-dump -o ./ -Hr [output-dir] [executable]

You should now have the headers.

Developing extensions

The existing tweaks are commented, so take a look at those. Each application is different but I'll outline the main implementation.

When creating a theos tweak for ChatHeads, it must follow the naming convention of MH[YourApp]Support.dylib to allow the package to show up in ChatHeads "Installed Extensions" section. The package name can be whatever you'd like (eg: ChatHeads Facebook Messenger Support, FB Support, FB Messenger for ChatHeads).

Don't forget to filter the BundleID of the target application.

In the AppDelegate, hook application:didFinishLaunchingWithOptions: and create an instance of RBS for com.c1d3r.messagehub.

Send the registerExtension message to ChatHeads, along with the app's bundleId, and add an observer for openConversation.

I also send a debug message, telling ChatHeads the application was launched.

Next, you'll need to find the message received function. When that is called, we need to parse through the message to find all of the information. This includes (NSString *) conversationId, (NSArray *) recipients, (NSString *) message, and (NSString *) bundleId.

Here is an example of what should be sent to ChatHeads. All of these values will change depending on the client application, but it'll work with ChatHeads, since ChatHeads will just send this info back to the client app.

      [center sendMessageName:@"messageReceived" userInfo:@{
        @"conversationId" : @"00000001",
        @"recipients" : @[
                           @{
                             @"name": @"c1d3r",
                             @"id": @"abc123",
                             @"imageData": UIImagePNGRepresentation([UIImage new])
                           }
                         ],
        @"message" : @"Hello there! This is an example of a message being recived by the client application!",
        @"bundleId" : [UIApplication displayIdentifier]
      }];

Hope this helps get you started. It comes down to a lot of trial and error. I've tried reverse engineering with tools like Hopper, but I've found the best way to find what your looking for is to just filter the dumped headers by method/class name.

The current tweaks (FB Messenger, SMS, WhatsApp) all very quite a bit, both due to experimenting with different implementations, as well as the how the developers of the apps have written them.

I've recently been in talks with a team who are working on a web-based solution for something similar, which may turn out to be a more reliable implementation due to the nature of a integrating directly with the client-apps API, rather than hooking a front end app receiving data from said API.

Publishing

In ChatHeads’ settings, I have a page to display the Available Extensions, tapping an extension will open it in Cydia (or Sileo). If you create an extension, let me know and I'll add it to the list of available extensions! I can also deploy it to my repo if you're interested.

If you have any questions, feel free to get in touch. Thanks for looking, I hope you create something awesome!

Twitter: @c1d3rdev Email: c1d3rdev@gmail.com