secp-ffi

rust-secp256k1 uniffi bindings for kotlin and swift

1. Build Binaries

Prerequisite

# rust - targets
rustup target add aarch64-linux-android   # android - arm64-v8a
rustup target add aarch64-apple-darwin    # jvm - arm
rustup target add x86_64-apple-darwin     # jvm - x86

# android - ndk environment variables
export CFLAGS="-D__ANDROID_MIN_SDK_VERSION__=24"
export AR="llvm-ar"
export CARGO_TARGET_AARCH64_LINUX_ANDROID_LINKER="aarch64-linux-android24-clang"
export CC="aarch64-linux-android24-clang"

Build

# android - arm64-v8a (modern hw)
cargo build --profile release-smaller --target aarch64-linux-android
# TODO android - x86_64 (emulators) 
# TODO android - armeabi-v7a (old 32-bit hw)
  
# jvm - arm
cargo build --profile release-smaller --target aarch64-apple-darwin

# jvm - x86
#cargo build --profile release-smaller --target x86_64-apple-darwin

2. Copy Binaries

# android - arm64-v8a
cp target/aarch64-linux-android/release-smaller/libsecpffi.so example/kotlin/app/src/main/jniLibs/arm64-v8a/libsecpffi.so

# jvm - arm
cp target/aarch64-apple-darwin/release-smaller/libsecpffi.dylib example/kotlin/app/src/main/resources/libsecpffi.dylib

3. Generate Bindings

a) Library mode (recommended):

Kotlin

# android - arm64-v8a
cargo run --bin uniffi-bindgen generate --library target/aarch64-linux-android/release-smaller/libsecpffi.so --language kotlin --out-dir example/kotlin/app/src/main/kotlin/ --no-format

# jvm - arm
cargo run --bin uniffi-bindgen generate --library target/aarch64-apple-darwin/release-smaller/libsecpffi.dylib --language kotlin --out-dir example/kotlin/app/src/main/kotlin/ --no-format

Swift

# TODO: `rustup target add <arch>`
#cargo run --bin uniffi-bindgen generate --library target/<arch>/<profile>/libsecpffi.so --language swift --out-dir <out_dir> --no-format

b) Single UDL mode (alternative):

# Kotlin
cargo run --features=uniffi/cli --bin uniffi-bindgen generate src/secp.udl --language kotlin

Example Apps

Kotlin (JVM App)

idea example/kotlin