llvm-string-obfuscator VS Obfuscate

For my use case, I need to create a llvm plugin which does some basic obfuscation to deter reversing of my application. I'm well aware obfuscation will not fully protect my application, but would like to implement it because one, the concept is interesting to me, and two, it will serve as a barrier to entry and might discourage some lazy bad actors. As an example, I have been referencing this project https://github.com/tsarpaul/llvm-string-obfuscator/blob/master/StringObfuscator/StringObfuscator.cpp , but would like to keep my code base totally in rust. I've searched around crates.io and can't find any library exposing bindings to the plugin pass api of llvm. Is there a crate already available to facilitate creating llvm passes in rust, or does anyone have any resources to suggest which could get me on the right path? I've created basic sys bindings for a c++ library (https://github.com/0xFounders/detour-sys), but am not an expert and was hoping there was already an established way to access the llvm pass api in rust.

if you hardcode the api key into your app, the apk can always get decompiled (apk -> dex -> dex2jar -> jar -> java decompiler). I personally hardcode sensitive api keys in C code, as #define constants. I use this class to obfiscate the C string constants. then I expose functions returning the api keys from C to java via JNI. I also use a mechanism to verify the apk signature, so that the C methods will only be called from the correct application (without this, others could take the .so library, include in their project, and just call the c functions from java / kotlin side, to get the api key). There was an article about this online, but i cannot find it right now.