Interesting, `www.auxbrain.com`. If we jump to its XREF, we get a garbled function, but what it seems to be doing is setting up
certain global values.
-So we have a potential API endpoint, let's put it to the test. We're not going to recompile anything yet or do any byte-patching,
-let's try a quick smoke-test. Ensure your phone is rooted and you have a variant of Xposed Framework installed (I used LSPosed).
-We will need to unarm the SSL pinning present in most apps, including this one, I used [io.github.tehcneko.sslunpinning](https://github.com/Xposed-Modules-Repo/io.github.tehcneko.sslunpinning) module.
-(Note: I know it is possible to repackage the app to do SSL unpinning in most cases, but in many cases, you won't know if it's worth the effort yet)
+## The smoke-test
-Next, install [AdAway app from F-Droid](https://f-droid.org/packages/org.adaway/) so we can setup a redirection on any network we are on.
+So we have a potential API endpoint, let's put it to the test. We can do a quick smoke test by setting up a webserver.
+
+Install [AdAway app from F-Droid](https://f-droid.org/packages/org.adaway/) so we can setup a redirection on any network we are on.
Inside AdAway, add a redirection rule for the address we just found and point it to an IP address in your LAN that will run the API server.
-Generate a self-signed certificate authority and a certificate signed by it and run a webserver with both HTTP and HTTPS on the API server machine.
-Import the self-signed CA to your phone's truststore. Once all of that is done, run the app for first time.
+(NOTE: AdAway doesn't detect any subdomains nor can it do wildcard, you will need to include the FQDN of the API endpoint `www.auxbrain.com`)
+Once you're done setting up the redirection, run any webserver such as nginx for a quick and dirty test.
```
192.168.1.212 - - [...] "POST /ei/first_contact HTTP/1.1" 404 0 "-"
```
a contract database and try scheduling them like the game originally did - a "Leggacy" contract every Friday and regular contracts showing up every 1-2 weeks
for roughly 2 weeks.
-## Rootless SSL Unpinning + Endpoint URL patching
-Let's make the app not require a VPN or root privileges - let's make user CAs work and the endpoint URL something we control on the public net.
-Start off by pulling the following repository
-```
-git clone https://github.com/ilya-kozyr/android-ssl-pinning-bypass.git
-python3 -m venv .venv
-source .venv/bin/activate
-pip install -r requirements.txt
-cp /path/to/your/apk .
-python3 apk-rebuild.py egginc.apk --pause
-```
-
-Open a new terminal window, the script will wait for us to perform modifications, enter the created folder `egginc.apk-decompiled` and `lib`.
-
-We have two folders here now, `arm64-v8a` and `armeabi-v7a`, just as we saw when we pulled the .so file out of the apk earlier. Let's tackle
-the 64-bit build first.
-
-For arm64 build it was really simple to perform bytepatch on the said endpoint. We already know it's supposed to look as `G?www.auxbrain.com` - let's probe the .so library a bit.
-```
-$> hexdump -C libegginc.so | grep "ww.auxbrain.co" -A2 -B2
-00b02b40 cd cc 4c 3f 00 00 00 00 00 00 00 00 00 00 80 3f |..L?...........?|
-00b02b50 00 00 00 00 00 00 00 00 00 00 00 00 14 ae 47 3f |..............G?|
-00b02b60 77 77 77 2e 61 75 78 62 72 61 69 6e 2e 63 6f 6d |www.auxbrain.com|
-00b02b70 00 48 54 54 50 20 52 45 51 3a 20 25 64 00 64 61 |.HTTP REQ: %d.da|
-00b02b80 74 61 3d 00 65 69 2f 66 69 72 73 74 5f 63 6f 6e |ta=.ei/first_con
-```
-
-We seem to have nothing blocking our way, let's create hex representations of `G?www.auxbrain.com` and a target domain of equal length, for example `G?eggs.based.quest`.
-
-(Note: You can choose a shorter name as well, if you null-terminate the extra bytes as padding)
-```
-$> echo "G?www.auxbrain.com" | hexdump -ve '1/1 "%.2X"'
-473F7777772E617578627261696E2E636F6D0A
-$> echo "G?eggs.based.quest" | hexdump -ve '1/1 "%.2X"'
-473F656767732E62617365642E71756573740A
-```
-
-Remove the trailing `0A` from end of both hex strings and now proceed as follows:
-```
-# Place the source in first bracket of sed and the new URL at second bracket.
-hexdump -ve '1/1 "%.2X"' libegginc.so | sed "s/473F7777772E617578627261696E2E636F6D/473F656767732E62617365642E7175657374/g" | xxd -r -p > patched.so
-```
-
-Huzzah! We now have a patched linked-library for the arm64 build. Let's also patch the 32-bit version.
-```
-$> hexdump -C libegginc.so | grep "ww.auxbrain.co" -A2 -B2
-0087b770 69 67 68 5f 74 6f 6f 5f 6d 61 6e 79 5f 70 78 00 |igh_too_many_px.|
-0087b780 74 61 62 6c 65 74 5f 68 64 70 69 00 00 00 00 00 |tablet_hdpi.....|
-0087b790 77 77 77 2e 61 75 78 62 72 61 69 6e 2e 63 6f 6d |www.auxbrain.com|
-0087b7a0 00 00 00 00 00 00 00 00 65 69 2f 66 69 72 73 74 |........ei/first|
-0087b7b0 5f 63 6f 6e 74 61 63 74 00 00 00 00 00 00 00 00 |_contact........|
-```
-This one lacks the `G?` prefix on API endpoint, but we still have null terminators we can rely on. Let's replace the `473F` from our previous strings with `0000`.
-```
-# Place the source in first bracket of sed and the new URL at second bracket.
-hexdump -ve '1/1 "%.2X"' libegginc.so | sed "s/00007777772E617578627261696E2E636F6D/0000656767732E62617365642E7175657374/g" | xxd -r -p > patched.so
-```
-
-Replace both of the libegginc.so files with the patched.so files. Move back to main terminal window and press ENTER.
-
-We now have a patched and debug signed apk for the game that isn't SSL pinned and contains a custom API endpoint we control without a VPN.
-
## Conclusion so far
We have created a (rather ugly looking) server emulator for the game. It functions, but it needs a lot of work still before we can call it ready.
If you have followed this far, give yourself pat on the back - if you actually tried to run this code, give yourself an extra pat on the back.
I won't give any promises for a part 2 any time soon, but I will be trying to make this feature complete, so without further ado, here are the git repository links:
[github.com](https://github.com/cernodile/reEgg), [git.based.quest](https://git.based.quest/?p=reEgg.git;a=tree;h=refs/heads/master;hb=refs/heads/master).
+Next time we will dive into apps that use SSL/TLS and making onboarding for your friends easier.
+
Thank you for reading and making it all the way to the end,
- Cernodile
projects / web-hugo.git / blobdiff