com.jcraft.jsch

Interface Cipher

All Known Implementing Classes:

CipherNone

public interface Cipher

Usually not to be used by applications. A cipher object encapsulates some encryption or decryption algorithm.

The Cipher implementations used by the library can be selected using configuration options. The package com.jcraft.jsch.jce contains such implementations based on the cryptographic algorithms given by the Java Cryptography Extension (JCE), these are the default values of the concerning options.

Field Summary

Fields

Modifier and Type	Field and Description
static int	DECRYPT_MODE Decryption mode constant for init(int, byte[], byte[]).
static int	ENCRYPT_MODE Encryption mode constant for init(int, byte[], byte[]).

Method Summary

Modifier and Type	Method and Description
int	getBlockSize() Returns the block size of this algorithm.
int	getIVSize() Returns the size of the identity vector for this cipher.
void	init(int mode, byte[] key, byte[] iv) Initializes the Cipher object for a new encryption or decryption operation.
boolean	isCBC() Checks whether this cipher is in Cipher Block Chaining mode.
void	update(byte[] input, int inOffset, int len, byte[] output, int outOffset) Encrypts or decrypts some more data.

Field Detail

ENCRYPT_MODE

static final int ENCRYPT_MODE

Encryption mode constant for init(int, byte[], byte[]).

See Also:

Constant Field Values

DECRYPT_MODE

static final int DECRYPT_MODE

Decryption mode constant for init(int, byte[], byte[]).

See Also:

Constant Field Values

Method Detail

getIVSize

int getIVSize()

Returns the size of the identity vector for this cipher.

getBlockSize

int getBlockSize()

Returns the block size of this algorithm.

init

void init(int mode,
          byte[] key,
          byte[] iv)
   throws Exception

Initializes the Cipher object for a new encryption or decryption operation.

Parameters:

mode - one of ENCRYPT_MODE or DECRYPT_MODE.

key - the key to use for the crypting operation.

iv - the initialization vector necessary for operation.

Throws:

Exception

update

void update(byte[] input,
            int inOffset,
            int len,
            byte[] output,
            int outOffset)
     throws Exception

Encrypts or decrypts some more data.

Parameters:

input - the array from which the plaintext (for encrypting) or ciphertext (for decrypting) should be taken.

inOffset - the position in input at which the data is to be found.

len - the length of the input in bytes. The same number of output bytes will be produced.

output - the array into which the ciphertext (for encrypting) or plaintext (for decrypting) will be written.

outOffset - the position in output from which on the data should be written.

Throws:

Exception

isCBC

boolean isCBC()

Checks whether this cipher is in Cipher Block Chaining mode.

Returns:

true if this cipher is in CBC mode, false if this cipher is in some other mode.