net.sf.mmm.crypto.asymmetric.sign.ec.bc

Class SignatureEcBcWithRecoveryId

java.lang.Object

net.sf.mmm.binary.api.BinaryType

net.sf.mmm.crypto.CryptoBinary

net.sf.mmm.crypto.asymmetric.sign.SignatureBinary

net.sf.mmm.crypto.asymmetric.sign.ec.bc.SignatureEcBc

net.sf.mmm.crypto.asymmetric.sign.ec.bc.SignatureEcBcWithRecoveryId

All Implemented Interfaces:

net.sf.mmm.binary.api.Binary, net.sf.mmm.binary.api.Streamable, SignatureWithPublicKeyRecovery

public class SignatureEcBcWithRecoveryId
extends SignatureEcBc
implements SignatureWithPublicKeyRecovery

SignatureEcBc with an extra byte for the recovery ID. Allows to recover the public key. This enables to transfer only a compact hash of the public key to save capacity. E.g. BitCoin uses this to transmit a BitCoin Address instead of the actual public key.

Since:

1.0.0

Field Summary

Fields

Modifier and Type	Field and Description
static byte	BITCOIN_COMPRESSED_OFFSET Additional recovery offset used for BitCoin for compressed public key.
static byte	BITCOIN_RECOVERY_OFFSET recovery offset used for BitCoin.
private static int	HEAD
private byte	recoveryOffset

Fields inherited from class net.sf.mmm.binary.api.BinaryType

data

Fields inherited from interface net.sf.mmm.binary.api.Binary

EMPTY_BYTE_ARRAY

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SignatureEcBcWithRecoveryId(CryptoEllipticCurveBc curve, byte[] data, BigInteger r, BigInteger s, byte recoveryOffset) The constructor.
	SignatureEcBcWithRecoveryId(CryptoEllipticCurveBc curve, byte[] data, byte recoveryOffset) The constructor.

Method Summary

Modifier and Type	Method and Description
protected int	getHead()
byte	getRecoveryId()
byte	getRecoveryIndex()
protected byte	getRecoveryOffset()
boolean	isCompressed()
static SignatureEcBcWithRecoveryId	of(CryptoEllipticCurveBc curve, BigInteger r, BigInteger s, byte[] message, org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey publicKey, byte recoveryOffset)
org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey	recoverPublicKey(byte[] message)

Methods inherited from class net.sf.mmm.crypto.asymmetric.sign.ec.bc.SignatureEcBc

calculateRecoveryIndex, createData, deserialize, getCurve, getR, getS, recoverPublicKey, recoverPublicKey

Methods inherited from class net.sf.mmm.binary.api.BinaryType

asStream, equals, format, formatBase64, formatHex, getData, getData, getDataByte, getLength, getMaxLength, getMinLength, hashCode, isZeros, parseBase64, parseHex, save, toBytes, toBytes, toInt, toLong, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.mmm.binary.api.Binary

format, formatBase64, formatHex, getData, getData, getDataByte, getLength, isZeros

Methods inherited from interface net.sf.mmm.binary.api.Streamable

asStream, save

Field Detail

BITCOIN_RECOVERY_OFFSET

public static final byte BITCOIN_RECOVERY_OFFSET

recovery offset used for BitCoin. Nobody knows why this magic number was chosen.

See Also:

Constant Field Values

BITCOIN_COMPRESSED_OFFSET

public static final byte BITCOIN_COMPRESSED_OFFSET

Additional recovery offset used for BitCoin for compressed public key.

See Also:

Constant Field Values

HEAD

private static final int HEAD

See Also:

Constant Field Values

recoveryOffset

private final byte recoveryOffset

Constructor Detail

SignatureEcBcWithRecoveryId

protected SignatureEcBcWithRecoveryId(CryptoEllipticCurveBc curve,
                                      byte[] data,
                                      BigInteger r,
                                      BigInteger s,
                                      byte recoveryOffset)

The constructor.

Parameters:

curve - the elliptic curve.

data - the binary data.

r - - see SignatureEcBc.getR().

s - - see SignatureEcBc.getS().

recoveryOffset - the recovery offset.

SignatureEcBcWithRecoveryId

public SignatureEcBcWithRecoveryId(CryptoEllipticCurveBc curve,
                                   byte[] data,
                                   byte recoveryOffset)

The constructor.

Parameters:

curve - the elliptic curve.

data - the binary data.

recoveryOffset - the recovery offset.

Method Detail

getHead

protected int getHead()

Overrides:

getHead in class SignatureEcBc

Returns:

number of bytes reserved at the beginning (header) of the binary data.

getRecoveryId

public byte getRecoveryId()

Returns:

the recovery ID containing the recovery index and compression information.

getRecoveryIndex

public byte getRecoveryIndex()

Returns:

the index to recover the public key from the signature. It is a value in the range from 0 to 3.

getRecoveryOffset

protected byte getRecoveryOffset()

Returns:

the offset to add to the recovery index for building the recovery ID.

isCompressed

public boolean isCompressed()

Returns:

true if public key was compressed, false otherwise.

recoverPublicKey

public org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey recoverPublicKey(byte[] message)

Specified by:

recoverPublicKey in interface SignatureWithPublicKeyRecovery

Parameters:

message - the payload (typically hash of message) that was signed when this signature was created.

Returns:

the recovered public key.

of

public static SignatureEcBcWithRecoveryId of(CryptoEllipticCurveBc curve,
                                             BigInteger r,
                                             BigInteger s,
                                             byte[] message,
                                             org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey publicKey,
                                             byte recoveryOffset)

Parameters:

curve - the elliptic curve.

r - the value r.

s - the value s.

message - the signed message (hash).

publicKey - the BCECPublicKey that was used to sign the message.

recoveryOffset - the recovery offset.

Returns:

the signature.