org.bouncycastle.crypto.encodings
Class OAEPEncoding

java.lang.Object
  org.bouncycastle.crypto.encodings.OAEPEncoding

All Implemented Interfaces:

AsymmetricBlockCipher

public class OAEPEncoding
extends java.lang.Object
implements AsymmetricBlockCipher

Optimal Asymmetric Encryption Padding (OAEP) - see PKCS 1 V 2.

Field Summary

private byte[]	defHash
private AsymmetricBlockCipher	engine
private boolean	forEncryption
private Digest	hash
private java.security.SecureRandom	random

Constructor Summary

OAEPEncoding(AsymmetricBlockCipher cipher)

OAEPEncoding(AsymmetricBlockCipher cipher, Digest hash)

OAEPEncoding(AsymmetricBlockCipher cipher, Digest hash, byte[] encodingParams)

Method Summary

byte[]	decodeBlock(byte[] in, int inOff, int inLen)
byte[]	encodeBlock(byte[] in, int inOff, int inLen)
int	getInputBlockSize() returns the largest size an input block can be.
int	getOutputBlockSize() returns the maximum size of the block produced by this cipher.
AsymmetricBlockCipher	getUnderlyingCipher()
void	init(boolean forEncryption, CipherParameters param) initialise the cipher.
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.
byte[]	processBlock(byte[] in, int inOff, int inLen) process the block of len bytes stored in in from offset inOff.

Methods inherited from class java.lang.Object

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

Field Detail

defHash

private byte[] defHash

hash

private Digest hash

engine

private AsymmetricBlockCipher engine

random

private java.security.SecureRandom random

forEncryption

private boolean forEncryption

Constructor Detail

OAEPEncoding

public OAEPEncoding(AsymmetricBlockCipher cipher)

OAEPEncoding

public OAEPEncoding(AsymmetricBlockCipher cipher,
                    Digest hash)

OAEPEncoding

public OAEPEncoding(AsymmetricBlockCipher cipher,
                    Digest hash,
                    byte[] encodingParams)

Method Detail

getUnderlyingCipher

public AsymmetricBlockCipher getUnderlyingCipher()

init

public void init(boolean forEncryption,
                 CipherParameters param)

Description copied from interface: AsymmetricBlockCipher

initialise the cipher.

Specified by:

init in interface AsymmetricBlockCipher

Parameters:

forEncryption - if true the cipher is initialised for encryption, if false for decryption.

param - the key and other data required by the cipher.

getInputBlockSize

public int getInputBlockSize()

Description copied from interface: AsymmetricBlockCipher

returns the largest size an input block can be.

Specified by:

getInputBlockSize in interface AsymmetricBlockCipher

Returns:

maximum size for an input block.

getOutputBlockSize

public int getOutputBlockSize()

Description copied from interface: AsymmetricBlockCipher

returns the maximum size of the block produced by this cipher.

Specified by:

getOutputBlockSize in interface AsymmetricBlockCipher

Returns:

maximum size of the output block produced by the cipher.

processBlock

public byte[] processBlock(byte[] in,
                           int inOff,
                           int inLen)
                    throws InvalidCipherTextException

Description copied from interface: AsymmetricBlockCipher

process the block of len bytes stored in in from offset inOff.

Specified by:

processBlock in interface AsymmetricBlockCipher

Parameters:

in - the input data

inOff - offset into the in array where the data starts

inLen - the length of the block to be processed.

Returns:

the resulting byte array of the encryption/decryption process.

Throws:

InvalidCipherTextException - data decrypts improperly.

encodeBlock

public byte[] encodeBlock(byte[] in,
                          int inOff,
                          int inLen)
                   throws InvalidCipherTextException

Throws:

InvalidCipherTextException

decodeBlock

public byte[] decodeBlock(byte[] in,
                          int inOff,
                          int inLen)
                   throws InvalidCipherTextException

Throws:

InvalidCipherTextException - if the decrypted block turns out to be badly formatted.

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.