Setting up the environment

CONTRIBUTING.md

@@ -0,0 +1,77 @@
+# Contributing
+
+This is based on information seen [here](https://github.com/mgp25/Instagram-API/wiki/Technical-information).
+
+#### Table of contents
+
+ 1. [Capturing Endpoints](#capturing-endpoints)
+ 2. [Reading the Signature Key](#reading-the-signature-key)
+ 3. [Capturing MQTT (Notifications)](#capturing-tls-requests)
+
+## Capturing Endpoints
+
+In order to capture endpoints you have to monitor the requests using a proxy.
+Instagram itself prevents that as anyone could monitor your requests, so you'll have to modify the app.
+Currently, [this](https://github.com/itsMoji/Instagram_SSL_Pinning) project by [itsMoji](https://github.com/itsMoji)
+allows you to disable the certificate-pinning which effectively makes the app accept every certificate.
+
+**Only use it in _your_ network as anyone with the certificate can then monitor your requests!**
+
+#### Step by step guide
+ The first steps are just for setting up the apk. You can also use [these](https://github.com/itsMoji/Instagram_SSL_Pinning#instagram-ssl-pinning) instructions.
+
+ 1. **Install** either the patched apk provided by itsMoji [here](https://github.com/itsMoji/Instagram_SSL_Pinning/tree/master/non-root)
+    **or** manually patch the apk (requires root access) 
+    by following [these](https://github.com/itsMoji/Instagram_SSL_Pinning#root-method) instructions.
+ 2. **Install** a http proxy on your host machine.
+     - Currently, the only proxy able to decrypt **TLS  1.3** is [Burp 1.7.x](https://portswigger.net/burp/releasesarchive/community)
+     (use version 1.7 although it's outdated, 2.x **won't work**) with [Java 11 or above](https://www.oracle.com/technetwork/java/javase/downloads/index.html).
+ 3. **Configure** your proxy to decrypt TLS 1.3 and **export** the *root certificate* to the phone/emulator.
+ 4. **Capture** the requests.
+
+#### General Infos
+
+- A request looking like `signed_body={HEX}.{Request}&ig_sig_key_version=4` has to be signed.
+
+## Reading the Signature Key
+
+The signature key is used to sign requests.
+
+#### Step by step guide
+
+ 1. [Setup Instagram on your phone like this](#capturing-endpoints)
+ 2. Install frida on your [device](https://www.frida.re/docs/android/) and [host machine](https://www.frida.re/docs/installation/).
+ 3. Start the frida-server on your device
+ 4. Connect to frida and the `com.instagram.android` process (using an emulator e.g. run `frida -U -n com.instagram.android`)
+ 5. Run ``` 
+    fscrambler = Module.findExportByName("libstrings.so","_ZN9Scrambler9getStringESs");
+    Interceptor.attach(ptr(fscrambler), {
+       onLeave: function (retval) {
+      send(Memory.readCString(retval));
+       }
+    });```
+ 6. Force a signed request inside the app by for example liking an image.
+ 7. You should now see `message: {'type': 'send', 'payload': '{SIGNATURE_KEY}'} data: none`
+
+
+## Capturing TLS Requests
+
+MQTT and FBNS are currently not implemented in the main library as they're not ready.
+You can see the current development [here](https://github.com/dilame/instagram-private-api/issues/845).
+They are built using MQTT (v3 and for FBNS a custom implementation of v3) and [Thrift](https://thrift.apache.org/)
+You'll probably have to use a Hex Editor for that.
+
+Currently, the only way of capturing these packets is using another proxy.
+
+#### Step by step guide
+
+If you are using Burp, **only** enable the proxy on `127.0.0.1`.
+
+ 1. [Setup Instagram on your phone like this](#capturing-endpoints)
+ 2. **Install** [Charles](https://www.charlesproxy.com/download/) (the test version only supports 30min per session, so save your results in another editor).
+ 3. **Configure** Charles as a **SOCKS** proxy (*Proxy* > *Proxy Settings...* > *Enable SOCKS Proxy*).
+ 4. **Export and install** the certificate (*Help* > *SSL Proxying* > *Install certificate on a Mobile Device or Remote Browser*).
+ 5. **Enable** SSL proxying for the domains `mqtt-mini.facebook.com:* and edge-mqtt.facebook.com:*` (*Proxy* > *SSL Proxying Settings...*).
+ 6. (optional) forward HTTP Packets to Burp (Charles only decrypts TLS 1.2):
+    * Go to *Proxy* > *External proxy settings...*, enable it and forward HTTP and HTTPS to `127.0.0.1:{BURP_PORT}`. 
+    * See your HTTP(S) requests in Burp.

README.md

@@ -146,6 +146,8 @@ If you need features that is not implemented - feel free to implement and create
 
 Plus we need some documentation, so if you are good in it - you are welcome.
 
+Setting up your environment is described [here](CONTRIBUTING.md).
+
 # Useful links
 
 [instagram-id-to-url-segment](https://www.npmjs.com/package/instagram-id-to-url-segment) - convert the image url fragment to the media ID