Install

Repository:

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

Add dependency:

dependencies {
    compile 'io.github.novacrypto:BIP44:2019.01.27'
}

Usage

Fluent construction

AddressIndex addressIndex = BIP44
                                .m()
                                .purpose44()
                                .coinType(2)
                                .account(1)
                                .external()
                                .address(5);

To string

String path = m().purpose44()
                 .coinType(2)
                 .account(1)
                 .external()
                 .address(5)
                 .toString(); //"m/44'/2'/1'/0/5"

Deriving

Using NovaCrypto/BIP32Derivation keys.

From root

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

Account from root

Account account = m().purpose44()
                     .coinType(2)
                     .account(1);
YourKeyType addressKey = derive
                     .derive(account, Account.DERIVATION);

From account private

Derive<YourKeyType> derive = new CkdFunctionDerive<>((parent, childIndex) -> {/*your CKD function*/}, accountPrivateKey);
YourKeyType addressKey = derive
                     .derive(addressIndex, AddressIndex.DERIVATION_FROM_ACCOUNT);

From account public

Derive<YourKeyType> derive = new CkdFunctionDerive<>((parent, childIndex) -> {/*your CKD function*/}, accountPublicKey);
YourKeyType addressKey = derive
                     .derive(addressIndex, AddressIndex.DERIVATION_FROM_ACCOUNT);

Deriving from NovaCrypto BIP32

Using NovaCrypto/BIP32 keys, which implement Derive<> directly:

WIP

!!! Note that BIP32 is a work in progress and you shouldn’t use this just yet for any main net transactions. !!!

From root

PrivateKey addressKey = rootPrivateKey
                     .derive(addressIndex, AddressIndex.DERIVATION);

Account from root

Account account = m().purpose44()
                     .coinType(2)
                     .account(1);
PrivateKey addressKey = rootPrivateKey
                     .derive(account, Account.DERIVATION);

From account private

PrivateKey addressKey = accountPrivateKey
                     .derive(addressIndex, AddressIndex.DERIVATION_FROM_ACCOUNT);

From account public

PublicKey addressKey = accountPublicKey
                     .derive(addressIndex, AddressIndex.DERIVATION_FROM_ACCOUNT);