org.bouncycastle.crypto.signers
Class PSSSigner

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

All Implemented Interfaces:

Signer

public class PSSSigner
extends java.lang.Object
implements Signer

RSA-PSS as described in PKCS# 1 v 2.1.

Note: the usual value for the salt length is the number of bytes in the hash function.

Field Summary

private byte[]	block
private AsymmetricBlockCipher	cipher
private Digest	digest
private int	emBits
private int	hLen
private byte[]	mDash
private java.security.SecureRandom	random
private byte[]	salt
private int	sLen
private byte	trailer
static byte	TRAILER_IMPLICIT

Constructor Summary

PSSSigner(AsymmetricBlockCipher cipher, Digest digest, int sLen)
basic constructor

PSSSigner(AsymmetricBlockCipher cipher, Digest digest, int sLen, byte trailer)

Method Summary

private void	clearBlock(byte[] block) clear possible sensitive data
byte[]	generateSignature() generate a signature for the message we've been loaded with using the key we were initialised with.
void	init(boolean forSigning, CipherParameters param) Initialise the signer for signing or verification.
private void	ItoOSP(int i, byte[] sp) int to octet string.
private byte[]	maskGeneratorFunction1(byte[] Z, int zOff, int zLen, int length) mask generator function, as described in PKCS1v2.
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 internal state represents the signature described in the passed in array.

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 byte TRAILER_IMPLICIT

See Also:

Constant Field Values

digest

private Digest digest

cipher

private AsymmetricBlockCipher cipher

random

private java.security.SecureRandom random

hLen

private int hLen

sLen

private int sLen

emBits

private int emBits

salt

private byte[] salt

mDash

private byte[] mDash

block

private byte[] block

trailer

private byte trailer

Constructor Detail

PSSSigner

public PSSSigner(AsymmetricBlockCipher cipher,
                 Digest digest,
                 int sLen)

basic constructor

Parameters:

cipher - the assymetric cipher to use.

digest - the digest to use.

sLen - the length of the salt to use (in bytes).

PSSSigner

public PSSSigner(AsymmetricBlockCipher cipher,
                 Digest digest,
                 int sLen,
                 byte trailer)

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.

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,
                                DataLengthException

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

Specified by:

generateSignature in interface Signer

Throws:

CryptoException

DataLengthException

verifySignature

public boolean verifySignature(byte[] signature)

return true if the internal state represents the signature described in the passed in array.

Specified by:

verifySignature in interface Signer

ItoOSP

private void ItoOSP(int i,
                    byte[] sp)

int to octet string.

maskGeneratorFunction1

private byte[] maskGeneratorFunction1(byte[] Z,
                                      int zOff,
                                      int zLen,
                                      int length)

mask generator function, as described in PKCS1v2.