io.neow3j.wallet.Bip39Account Maven / Gradle / Ivy
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package io.neow3j.wallet;
import static io.neow3j.crypto.Hash.sha256;
import io.neow3j.crypto.ECKeyPair;
import io.neow3j.crypto.MnemonicUtils;
import io.neow3j.crypto.SecureRandomUtils;
/**
* Class encapsulating a BIP-39 compatible NEO account.
*/
public class Bip39Account extends Account {
/**
* Generated BIP-39 mnemonic for the account.
*/
private String mnemonic;
private Bip39Account() {
}
protected Bip39Account(String mnemonic) {
super();
this.mnemonic = mnemonic;
}
public Bip39Account(ECKeyPair ecKeyPair) {
super(ecKeyPair);
}
private Bip39Account mnemonic(String mnemonic) {
this.mnemonic = mnemonic;
return this;
}
/**
* Generates a BIP-39 compatible NEO account. The private key for the wallet can be calculated using following
* algorithm:
*
* Key = SHA-256(BIP_39_SEED(mnemonic, password))
*
*
* The password will *only* be used as passphrase for BIP-39 seed (i.e., used to recover the account).
*
* @param password the passphrase with which to encrypt the private key.
* @return a BIP-39 compatible Neo account.
*/
public static Bip39Account create(final String password) {
byte[] initialEntropy = SecureRandomUtils.generateRandomBytes(16);
String mnemonic = MnemonicUtils.generateMnemonic(initialEntropy);
byte[] seed = MnemonicUtils.generateSeed(mnemonic, password);
ECKeyPair keyPair = ECKeyPair.create(sha256(seed));
return new Bip39Account(keyPair).mnemonic(mnemonic);
}
/**
* Recovers a key pair based on BIP-39 mnemonic and password.
*
* @param password the passphrase given when the BIP-39 account was generated.
* @param mnemonic the generated mnemonic with the given passphrase.
* @return a Bip39Account builder.
*/
public static Bip39Account fromBip39Mnemonic(String password, String mnemonic) {
byte[] seed = MnemonicUtils.generateSeed(mnemonic, password);
ECKeyPair ecKeyPair = ECKeyPair.create(sha256(seed));
return new Bip39Account(ecKeyPair).mnemonic(mnemonic);
}
public String getMnemonic() {
return mnemonic;
}
}