org.bouncycastle.crypto.signers
Class ISO9796d2Signer

java.lang.Object
  org.bouncycastle.crypto.signers.ISO9796d2Signer

All Implemented Interfaces:

Signer, SignerWithRecovery

public class ISO9796d2Signer
extends java.lang.Object
implements SignerWithRecovery

ISO9796-2 - mechanism using a hash function with recovery (scheme 1)

Field Summary

private byte[]	block
private AsymmetricBlockCipher	cipher
private Digest	digest
private boolean	fullMessage
private int	keyBits
private byte[]	mBuf
private int	messageLength
private byte[]	recoveredMessage
private int	trailer
static int	TRAILER_IMPLICIT
static int	TRAILER_RIPEMD128
static int	TRAILER_RIPEMD160
static int	TRAILER_SHA1

Constructor Summary

ISO9796d2Signer(AsymmetricBlockCipher cipher, Digest digest)
Constructor for a signer with an explicit digest trailer.

ISO9796d2Signer(AsymmetricBlockCipher cipher, Digest digest, boolean implicit)
Generate a signer for the with either implicit or explicit trailers for ISO9796-2.

Method Summary

private void	clearBlock(byte[] block) clear possible sensitive data
byte[]	generateSignature() generate a signature for the loaded message using the key we were initialised with.
byte[]	getRecoveredMessage() Return a reference to the recoveredMessage message.
boolean	hasFullMessage() Return true if the full message was recoveredMessage.
void	init(boolean forSigning, CipherParameters param) Initialise the signer for signing or verification.
private boolean	isSameAs(byte[] a, byte[] b) compare two byte arrays.
void	reset() reset the internal state
void	update(byte b) update the internal digest with the byte b
void	update(byte[] in, int off, int len) update the internal digest with the byte array in
boolean	verifySignature(byte[] signature) return true if the signature represents a ISO9796-2 signature for the passed in message.

Methods inherited from class java.lang.Object

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

Field Detail

TRAILER_IMPLICIT

public static final int TRAILER_IMPLICIT

See Also:

Constant Field Values

TRAILER_RIPEMD160

public static final int TRAILER_RIPEMD160

See Also:

Constant Field Values

TRAILER_RIPEMD128

public static final int TRAILER_RIPEMD128

See Also:

Constant Field Values

TRAILER_SHA1

public static final int TRAILER_SHA1

See Also:

Constant Field Values

digest

private Digest digest

cipher

private AsymmetricBlockCipher cipher

trailer

private int trailer

keyBits

private int keyBits

block

private byte[] block

mBuf

private byte[] mBuf

messageLength

private int messageLength

fullMessage

private boolean fullMessage

recoveredMessage

private byte[] recoveredMessage

Constructor Detail

ISO9796d2Signer

public ISO9796d2Signer(AsymmetricBlockCipher cipher,
                       Digest digest,
                       boolean implicit)

Generate a signer for the with either implicit or explicit trailers for ISO9796-2.

Parameters:

cipher - base cipher to use for signature creation/verification

digest - digest to use.

implicit - whether or not the trailer is implicit or gives the hash.

ISO9796d2Signer

public ISO9796d2Signer(AsymmetricBlockCipher cipher,
                       Digest digest)

Constructor for a signer with an explicit digest trailer.

Parameters:

cipher - cipher to use.

digest - digest to sign with.

Method Detail

init

public void init(boolean forSigning,
                 CipherParameters param)

Description copied from interface: Signer

Initialise the signer for signing or verification.

Specified by:

init in interface Signer

Parameters:

forSigning - true if for signing, false otherwise

param - necessary parameters.

isSameAs

private boolean isSameAs(byte[] a,
                         byte[] b)

compare two byte arrays.

clearBlock

private void clearBlock(byte[] block)

clear possible sensitive data

update

public void update(byte b)

update the internal digest with the byte b

Specified by:

update in interface Signer

update

public void update(byte[] in,
                   int off,
                   int len)

update the internal digest with the byte array in

Specified by:

update in interface Signer

reset

public void reset()

reset the internal state

Specified by:

reset in interface Signer

generateSignature

public byte[] generateSignature()
                         throws CryptoException

generate a signature for the loaded message using the key we were initialised with.

Specified by:

generateSignature in interface Signer

Throws:

CryptoException

verifySignature

public boolean verifySignature(byte[] signature)

return true if the signature represents a ISO9796-2 signature for the passed in message.

Specified by:

verifySignature in interface Signer

hasFullMessage

public boolean hasFullMessage()

Return true if the full message was recoveredMessage.

Specified by:

hasFullMessage in interface SignerWithRecovery

Returns:

true on full message recovery, false otherwise.

See Also:

SignerWithRecovery.hasFullMessage()

getRecoveredMessage

public byte[] getRecoveredMessage()

Return a reference to the recoveredMessage message.

Specified by:

getRecoveredMessage in interface SignerWithRecovery

Returns:

the full/partial recoveredMessage message.

See Also:

SignerWithRecovery.getRecoveredMessage()