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)

Constructor Summary

Constructors

Constructor and Description
ISO9796d2Signer(AsymmetricBlockCipher cipher, Digest digest) Constructor for a signer with an explicit digest trailer.
ISO9796d2Signer(AsymmetricBlockCipher cipher, Digest digest, boolean implicit) Generate a signer with either implicit or explicit trailers for ISO9796-2.

Method Summary

Modifier and Type	Method and Description
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, either as it was added to a just generated signature, or extracted from a verified one.
boolean	hasFullMessage() Return true if the full message was recoveredMessage.
void	init(boolean forSigning, CipherParameters param) Initialise the signer for signing or verification.
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
void	updateWithRecoveredMessage(byte[] signature) Perform an update with the recovered message before adding any other data.
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

Constructor Detail

ISO9796d2Signer

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

Generate a signer 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.

updateWithRecoveredMessage

public void updateWithRecoveredMessage(byte[] signature)
                                throws InvalidCipherTextException

Description copied from interface: SignerWithRecovery

Perform an update with the recovered message before adding any other data. This must be the first update method called, and calling it will result in the signer assuming that further calls to update will include message content past what is recoverable.

Specified by:

updateWithRecoveredMessage in interface SignerWithRecovery

Parameters:

signature - the signature that we are in the process of verifying.

Throws:

InvalidCipherTextException

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, either as it was added to a just generated signature, or extracted from a verified one.

Specified by:

getRecoveredMessage in interface SignerWithRecovery

Returns:

the full/partial recoveredMessage message.

See Also:

SignerWithRecovery.getRecoveredMessage()