Package org.bitcoinj.crypto

Class MnemonicCode

java.lang.Object

org.bitcoinj.crypto.MnemonicCode

public class MnemonicCode
extends Object

A MnemonicCode object may be used to convert between binary seed values and lists of words per the BIP 39 specification

Field Summary

Fields

Modifier and Type	Field	Description
static final Instant	BIP39_STANDARDISATION_TIME	UNIX time for when the BIP39 standard was finalised.
static final int	BIP39_STANDARDISATION_TIME_SECS	Deprecated. Use BIP39_STANDARDISATION_TIME
static MnemonicCode	INSTANCE

Constructor Summary

Constructors

Constructor	Description
MnemonicCode()	Initialise from the included word list.
MnemonicCode(InputStream wordstream, String wordListDigest)	Creates an MnemonicCode object, initializing with words read from the supplied input stream.

Method Summary

Modifier and Type	Method	Description
void	check(List<String> words)	Check to see if a mnemonic word list is valid.
List<String>	getWordList()	Gets the word list this code uses.
byte[]	toEntropy(List<String> words)	Convert mnemonic word list to original entropy value.
List<String>	toMnemonic(byte[] entropy)	Convert entropy data to mnemonic word list.
static byte[]	toSeed(List<String> words, String passphrase)	Convert mnemonic word list to seed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BIP39_STANDARDISATION_TIME

public static final Instant BIP39_STANDARDISATION_TIME

UNIX time for when the BIP39 standard was finalised. This can be used as a default seed birthday.

BIP39_STANDARDISATION_TIME_SECS

@Deprecated
public static final int BIP39_STANDARDISATION_TIME_SECS

Deprecated.

Use BIP39_STANDARDISATION_TIME

INSTANCE

public static MnemonicCode INSTANCE

Constructor Details

MnemonicCode

public MnemonicCode()
             throws IOException

Initialise from the included word list. Won't work on Android.

Throws:

IOException

MnemonicCode

public MnemonicCode(InputStream wordstream,
 String wordListDigest)
             throws IOException,
IllegalArgumentException

Creates an MnemonicCode object, initializing with words read from the supplied input stream. If a wordListDigest is supplied the digest of the words will be checked.

Parameters:

wordstream - input stream of 2048 line-seperated words

wordListDigest - hex-encoded Sha256 digest to check against

Throws:

IOException - if there was a problem reading the steam

IllegalArgumentException - if list size is not 2048 or digest mismatch

Method Details

getWordList

public List<String> getWordList()

Gets the word list this code uses.

Returns:

unmodifiable word list

toSeed

public static byte[] toSeed(List<String> words,
 String passphrase)

Convert mnemonic word list to seed.

toEntropy

public byte[] toEntropy(List<String> words)
                 throws MnemonicException.MnemonicLengthException,
MnemonicException.MnemonicWordException,
MnemonicException.MnemonicChecksumException

Convert mnemonic word list to original entropy value.

Throws:

MnemonicException.MnemonicLengthException

MnemonicException.MnemonicWordException

MnemonicException.MnemonicChecksumException

toMnemonic

public List<String> toMnemonic(byte[] entropy)

Convert entropy data to mnemonic word list.

Parameters:

entropy - entropy bits, length must be a multiple of 32 bits

check

public void check(List<String> words)
           throws MnemonicException

Check to see if a mnemonic word list is valid.

Throws:

MnemonicException