ro.raducora.utils.encryption
Class RC4

java.lang.Object
  |
  +--ro.raducora.utils.encryption.RC4

public final class RC4

extends java.lang.Object

This class implements the RC4 (TM) stream cipher.

Constructor Summary

RC4()
Constructs an RC4 cipher object, in the UNINITIALIZED state.

Method Summary

java.lang.Object	clone() Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).
int	engineBlockSize() SPI : Returns the length of an input block, in bytes.
void	engineInitDecrypt(byte[] key) SPI : Initializes this cipher for decryption, using the specified key.
void	engineInitEncrypt(byte[] key) SPI : Initializes this cipher for encryption, using the specified key.
protected int	engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) SPI : This is the main engine method for updating data.
boolean	getState()
void	rc4(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) RC4 encryption/decryption.

Methods inherited from class java.lang.Object

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

Constructor Detail

RC4

public RC4()

Constructs an RC4 cipher object, in the UNINITIALIZED state.

Method Detail

getState

public boolean getState()

Returns:

true for encrypt false for decrypt

clone

public final java.lang.Object clone()
                             throws java.lang.CloneNotSupportedException

Always throws a CloneNotSupportedException (cloning of ciphers is not supported for security reasons).

Overrides:

clone in class java.lang.Object

java.lang.CloneNotSupportedException

engineBlockSize

public int engineBlockSize()

SPI : Returns the length of an input block, in bytes.

Returns:

the length in bytes of an input block for this cipher.

engineInitEncrypt

public void engineInitEncrypt(byte[] key)
                       throws java.security.InvalidKeyException

SPI : Initializes this cipher for encryption, using the specified key.

Parameters:

key - the key to use for encryption.

Throws:

java.security.InvalidKeyException - if the key is invalid.

engineInitDecrypt

public void engineInitDecrypt(byte[] key)
                       throws java.security.InvalidKeyException

SPI : Initializes this cipher for decryption, using the specified key.

Parameters:

key - the key to use for decryption.

Throws:

java.security.InvalidKeyException - if the key is invalid.

engineUpdate

protected int engineUpdate(byte[] in,
                           int inOffset,
                           int inLen,
                           byte[] out,
                           int outOffset)

SPI : This is the main engine method for updating data.

in and out may be the same array, and the input and output regions may overlap.

Parameters:

in - the input data.

inOffset - the offset into in specifying where the data starts.

inLen - the length of the subarray.

out - the output array.

outOffset - the offset indicating where to start writing into the out array.

Returns:

the number of bytes written.

rc4

public void rc4(byte[] in,
                int inOffset,
                int inLen,
                byte[] out,
                int outOffset)

RC4 encryption/decryption. The input and output regions are assumed not to overlap.

Parameters:

in - the input data.

inOffset - the offset into in specifying where the data starts.

inLen - the length of the subarray.

out - the output array.

outOffset - the offset indicating where to start writing into the out array.