iaik.pkcs.pkcs11.provider.ciphers

Class PKCS5Padding

java.lang.Object

iaik.pkcs.pkcs11.provider.ciphers.PKCS5Padding

public class PKCS5Padding
extends java.lang.Object

Implements a padding scheme as specified by the PKCS#5: Password-Based Encryption Standard.

An application wishing to use PKCS5Padding, specifies this in the transformation string when instantiating the Cipher class, e.g.:

 Cipher des_cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
 

Version:

File Revision 15

Field Summary

Fields

Modifier and Type	Field and Description
protected int	blockSize_
protected static int	DEFAULTBLOCKSIZE
protected java.security.SecureRandom	random_

Constructor Summary

Constructors

Constructor and Description
PKCS5Padding()

Method Summary

Modifier and Type	Method and Description
protected java.lang.String	getName() Return the name of this padding.
byte[]	pad(byte[] in, int off, int len) Pads the specified sub-array of the given byte array.
protected byte[]	padFinal(byte[] data, int offset, int length) Finalize padding and return all padded bytes.
protected void	setBlockSize(int blockSize)
protected void	setRandom(java.security.SecureRandom random) Sets the random generator to be used (if required).
byte[]	unpad(byte[] in, int off, int len) Removes any padding bytes from the given padded message.
protected byte[]	unpadFinal(byte[] data, int offset, int length) Finalize unpadding and return all unpadded bytes.

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULTBLOCKSIZE

protected static int DEFAULTBLOCKSIZE

blockSize_

protected int blockSize_

random_

protected java.security.SecureRandom random_

Constructor Detail

PKCS5Padding

public PKCS5Padding()

Method Detail

pad

public byte[] pad(byte[] in,
                  int off,
                  int len)

Pads the specified sub-array of the given byte array.

Parameters:

in - - the byte array holding the message to be padded, big enough to hold the padding string.

off - - the offset within the given byte array, indicating the start position of the message to be padded

len - - the length of the message to be padded

Returns:

the number of padding bytes that have been necessary for padding the given message.

unpad

public byte[] unpad(byte[] in,
                    int off,
                    int len)

Removes any padding bytes from the given padded message.

Parameters:

in - - the byte array holding the message to be unpadded.

off - - the offset within the given byte array, indicating the start position of the padded message

len - - the length of the padded message

Returns:

the length of the unpadded message.

padFinal

protected byte[] padFinal(byte[] data,
                          int offset,
                          int length)
                   throws javax.crypto.BadPaddingException,
                          javax.crypto.IllegalBlockSizeException

Finalize padding and return all padded bytes.

Parameters:

data - the final bytes to be padded, may be null

Returns:

the padded bytes

Throws:

javax.crypto.BadPaddingException

javax.crypto.IllegalBlockSizeException

unpadFinal

protected byte[] unpadFinal(byte[] data,
                            int offset,
                            int length)
                     throws javax.crypto.BadPaddingException,
                            javax.crypto.IllegalBlockSizeException

Finalize unpadding and return all unpadded bytes.

Parameters:

data - the final bytes to be unpadded, may be null

Returns:

the unpadded bytes

Throws:

javax.crypto.BadPaddingException

javax.crypto.IllegalBlockSizeException

getName

protected java.lang.String getName()

Return the name of this padding.

Returns:

the padding name

setBlockSize

protected void setBlockSize(int blockSize)

setRandom

protected void setRandom(java.security.SecureRandom random)

Sets the random generator to be used (if required).

Parameters:

random - the random generator to be used