mirror of
https://github.com/SchildiChat/SchildiChat-android.git
synced 2024-12-29 12:28:36 +03:00
97 lines
3 KiB
Markdown
97 lines
3 KiB
Markdown
|
# Kotlin bindings for the Rust SDK crypto layer.
|
||
|
|
|
||
|
|
## Prerequisites
|
||
|
|
|
||
|
|
### Rust
|
||
|
|
|
||
|
|
To build the bindings [Rust] will be needed it can be either installed using an
|
||
|
|
OS specific package manager or directly with the provided [installer](https://rustup.rs/).
|
||
|
|
|
||
|
|
|
||
|
|
### Android NDK
|
||
|
|
|
||
|
|
The Android NDK will be required as well, it can be installed either through
|
||
|
|
Android Studio or directly using an [installer](https://developer.android.com/ndk/downloads).
|
||
|
|
|
||
|
|
### Uniffi
|
||
|
|
|
||
|
|
The bindings are using [uniffi] to generate the C translation layer between Rust
|
||
|
|
and Kotlin. Uniffi is a Rust project and can be installed with our freshly
|
||
|
|
installed Rust setup using:
|
||
|
|
|
||
|
|
```
|
||
|
|
$ cargo install uniffi_bindgen
|
||
|
|
```
|
||
|
|
|
||
|
|
### Configuring Rust for cross compilation
|
||
|
|
|
||
|
|
First we'll need to install the Rust target for our desired Android architecture,
|
||
|
|
for example:
|
||
|
|
|
||
|
|
```
|
||
|
|
# rustup target add aarch64-linux-android
|
||
|
|
```
|
||
|
|
|
||
|
|
This will add support to cross-compile for the aarch64-linux-android target,
|
||
|
|
Rust supports many different [targets], you'll have to make sure to pick the
|
||
|
|
right one for your device or emulator.
|
||
|
|
|
||
|
|
After this is done, we'll have to configure [Cargo] to use the correct linker
|
||
|
|
for our target. Cargo is configured using a TOML file that will be found in
|
||
|
|
`%USERPROFILE%\.cargo\config.toml` on Windows or `$HOME/.cargo/config` on Unix
|
||
|
|
platforms. More details and configuration options for Cargo can be found in the
|
||
|
|
official docs over [here](https://doc.rust-lang.org/cargo/reference/config.html).
|
||
|
|
|
||
|
|
```
|
||
|
|
[target.aarch64-linux-android]
|
||
|
|
ar = "NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin/ar"
|
||
|
|
linker = "NDK_HOME/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android30-clang"
|
||
|
|
```
|
||
|
|
|
||
|
|
## Building
|
||
|
|
|
||
|
|
A `Makefile` is provided that builds and installs the dynamic library into the
|
||
|
|
appropriate target specific `jniLibs` directory. But before we can get started
|
||
|
|
we'll need to tweak our Rust setup to allow cross compilation.
|
||
|
|
|
||
|
|
To enable cross compilation fro `olm-sys` which builds our libolm C library
|
||
|
|
we'll need to set the `ANDROID_NDK` environment variable to the location of our
|
||
|
|
Android NDK installation.
|
||
|
|
|
||
|
|
```
|
||
|
|
$ export ANDROID_NDK=$HOME/Android/Sdk/ndk/22.0.7026061/
|
||
|
|
```
|
||
|
|
|
||
|
|
### Makefile build
|
||
|
|
|
||
|
|
After the prerequisites have been installed and the environment variable has
|
||
|
|
been set a build for the `aarch64` target can be build using:
|
||
|
|
|
||
|
|
```
|
||
|
|
make aarch64
|
||
|
|
```
|
||
|
|
|
||
|
|
### Manual build
|
||
|
|
|
||
|
|
If the `Makefile` doesn't work on your system, the bindings can built for the `aarch64`
|
||
|
|
target with:
|
||
|
|
|
||
|
|
```
|
||
|
|
$ cargo build --target aarch64-linux-android
|
||
|
|
```
|
||
|
|
|
||
|
|
After that, a dynamic library can be found in the `target/aarch64-linux-android/debug` directory.
|
||
|
|
The library will be called `libmatrix_crypto.so` and needs to be renamed and
|
||
|
|
copied into the `jniLibs` directory:
|
||
|
|
|
||
|
|
```
|
||
|
|
$ cp target/aarch64-linux-android/debug/libmatrix_crypto.so \
|
||
|
|
../matrix-sdk-android/src/main/jniLibs/aarch64/libuniffi_olm.so
|
||
|
|
```
|
||
|
|
|
||
|
|
[Rust]: https://www.rust-lang.org/
|
||
|
|
[installer]: https://rustup.rs/
|
||
|
|
[targets]: https://doc.rust-lang.org/nightly/rustc/platform-support.html
|
||
|
|
[Cargo]: https://doc.rust-lang.org/cargo/
|
||
|
|
[uniffi]: https://github.com/mozilla/uniffi-rs/
|