Kotlin/Multiplatform wrapper for Bitcoin Core's secp256k1 library. Targets: JVM, Android, iOS & Linux.
secp256k1-kmp is available on maven central
Then, the actual dependency depends on your targeted platform(s):
Add the secp256k1
dependency to the common sourceSet, and the JNI dependencies to JVM and Android sourcesets:
// build.gradle.kts
kotlin {
jvm()
android()
linuxX64("linux")
ios()
sourceSets {
val commonMain by getting {
dependencies {
implementation(kotlin("stdlib-common"))
implementation("fr.acinq.secp256k1:secp256k1-kmp:$secp256k1_version")
}
}
val jvmMain by getting {
dependencies {
implementation(kotlin("stdlib"))
implementation("fr.acinq.secp256k1:secp256k1-kmp-jni-jvm:$secp256k1_version")
}
}
val androidMain by getting {
dependencies {
implementation(kotlin("stdlib"))
implementation("fr.acinq.secp256k1:secp256k1-kmp-jni-android:$secp256k1_version")
}
}
}
}
Native targets include libsecp256k1, called through KMP's c-interop, simply add the fr.acinq.secp256k1:secp256k1
dependency.
The JVM library uses JNI bindings for libsecp256k1, which is much faster than BouncyCastle. It will extract and load native bindings for your operating system in a temporary directory.
JNI libraries are included for:
Along this library, you must specify which JNI native library to use in your dependency manager:
fr.acinq.secp256k1:secp256k1-kmp-jni-jvm
dependency which imports all supported platforms.fr.acinq.secp256k1:secp256k1-kmp-jni-jvm-linux
for Linuxfr.acinq.secp256k1:secp256k1-kmp-jni-jvm-darwin
for Mac OS Xfr.acinq.secp256k1:secp256k1-kmp-jni-jvm-mingw
for Windowsfr.acinq.secp256k1:secp256k1-kmp-jni-android
dependencyIf you are using the JVM on an OS for which we don't provide JNI bindings (32 bits OS for example), you can use your own library native library by
adding the fr.acinq.secp256k1:secp256k1-kmp-jni-jvm
dependency and specifying its path with -Dfr.acinq.secp256k1.lib.path
and optionally its name with -Dfr.acinq.secp256k1.lib.name
(if unspecified bitcoink use the standard name for your OS i.e. libsecp256k1.so on Linux, secp256k1.dll on Windows, ...).
To compile your own JNI bindings, have a look add the native/build.sh
and jni/build.sh
scripts.
You can also specify the temporary directory where the library will be extracted with -Djava.io.tmpdir
or -Dfr.acinq.secp256k1.tmpdir
(if you want to use a different directory from -Djava.io.tmpdir
).
Please have a look at unit tests, more samples will be added soon.
secp256k1-kmp is a Kotlin Multiplatform wrapper for Bitcoin Core's secp256k1 library.
To build the library you need the following:
It may work with other Operating Systems and JDKs, but then you're on your own (in particular we don't plan to support 32 bits Operating Systems). To build the library and publish compiled artefacts locally (so they can be used by other projects):
./gradlew :build
./gradlew :publishToMavenLocal
To run all tests on all platforms:
./gradlew allTests
To run tests on a single platform, for example the JVM:
./gradlew jvmTest
If you want to skip building Android artefacts create a local.properties
file in the project's root directory and add the following line:
skip.android=true
secp256k1-kmp follows 2 simples rules:
"Porting" C/C++ code that uses secp256k1 should be a no-brainer and we should not have to document secp256k1-kmp
To extend this library and support methods that have been added to specific versions of secp256k1 you have to:
javac -h jni/c/headers/java jni/src/main/java/fr/acinq/secp256k1/Secp256k1CFunctions.java
You may also need to modify build files if you need to compile secp256k1 with custom options
We use secp256k1 through git submodules so you may also need to change what they point to