Install

Use either of these repositories:

repositories {
    jcenter()
}

(coming soon)

Or:

repositories {
    maven {
        url 'https://dl.bintray.com/novacrypto/BIP/'
    }
}

Add dependency:

dependencies {
    compile 'io.github.novacrypto:BIP32derivation:2019.01.27@jar'
}

Usage

Derive<YourKeyType> derive = new CkdFunctionDerive<>((parent, childIndex) -> {/*your CKD function*/}, yourRootKey);
YourKeyType ketAtPath = derive.derive("m/44'/0'/0'/0/0");

With own path type

If you don’t want to use strings to describe paths.

Derive<YourKeyType> derive = new CkdFunctionDerive<>((parent, childIndex) -> {/*your CKD function*/}, yourRootKey);
YourKeyType ketAtPath = derive.derive(YourCustomPathType, YourCustomDeriveImplementation);

Caching

CkdFunction<YourKeyType> ckd = (parent, childIndex) -> {/*your CKD function*/};
CkdFunction<YourKeyType> ckdWithCache = CkdFunctionResultCacheDecorator.newCacheOf(ckd);
Derive<YourKeyType> derive = new CkdFunctionDerive<>(ckdWithCache, yourRootKey);
YourKeyType ketAtPath1 = derive.derive("m/44'/0'/0'/0/0");
YourKeyType ketAtPath2 = derive.derive("m/44'/0'/0'/0/0");
assertSame(ketAtPath1, ketAtPath2);

Note you can use NovaCrypto/BIP44 to form the path with a fluent syntax.