org.bouncycastle.crypto.macs

Class CFBBlockCipherMac

Implemented Interfaces:
Mac

public class CFBBlockCipherMac
extends java.lang.Object
implements Mac

Constructor Summary

CFBBlockCipherMac(BlockCipher cipher)
create a standard MAC based on a CFB block cipher.
CFBBlockCipherMac(BlockCipher cipher, int cfbBitSize, int macSizeInBits)
create a standard MAC based on a block cipher with the size of the MAC been given in bits.
CFBBlockCipherMac(BlockCipher cipher, int cfbBitSize, int macSizeInBits, BlockCipherPadding padding)
create a standard MAC based on a block cipher with the size of the MAC been given in bits.
CFBBlockCipherMac(BlockCipher cipher, BlockCipherPadding padding)
create a standard MAC based on a CFB block cipher.

Method Summary

int
doFinal(byte[] out, int outOff)
String
getAlgorithmName()
int
getMacSize()
void
init(CipherParameters params)
void
reset()
Reset the mac generator.
void
update(byte in)
void
update(byte[] in, int inOff, int len)

Constructor Details

CFBBlockCipherMac

public CFBBlockCipherMac(BlockCipher cipher)
create a standard MAC based on a CFB block cipher. This will produce an authentication code half the length of the block size of the cipher, with the CFB mode set to 8 bits.
Parameters:
cipher - the cipher to be used as the basis of the MAC generation.

CFBBlockCipherMac

public CFBBlockCipherMac(BlockCipher cipher,
                         int cfbBitSize,
                         int macSizeInBits)
create a standard MAC based on a block cipher with the size of the MAC been given in bits. This class uses CFB mode as the basis for the MAC generation.

Note: the size of the MAC must be at least 24 bits (FIPS Publication 81), or 16 bits if being used as a data authenticator (FIPS Publication 113), and in general should be less than the size of the block cipher as it reduces the chance of an exhaustive attack (see Handbook of Applied Cryptography).

Parameters:
cipher - the cipher to be used as the basis of the MAC generation.
cfbBitSize - the size of an output block produced by the CFB mode.
macSizeInBits - the size of the MAC in bits, must be a multiple of 8.

CFBBlockCipherMac

public CFBBlockCipherMac(BlockCipher cipher,
                         int cfbBitSize,
                         int macSizeInBits,
                         BlockCipherPadding padding)
create a standard MAC based on a block cipher with the size of the MAC been given in bits. This class uses CFB mode as the basis for the MAC generation.

Note: the size of the MAC must be at least 24 bits (FIPS Publication 81), or 16 bits if being used as a data authenticator (FIPS Publication 113), and in general should be less than the size of the block cipher as it reduces the chance of an exhaustive attack (see Handbook of Applied Cryptography).

Parameters:
cipher - the cipher to be used as the basis of the MAC generation.
cfbBitSize - the size of an output block produced by the CFB mode.
macSizeInBits - the size of the MAC in bits, must be a multiple of 8.
padding - a padding to be used.

CFBBlockCipherMac

public CFBBlockCipherMac(BlockCipher cipher,
                         BlockCipherPadding padding)
create a standard MAC based on a CFB block cipher. This will produce an authentication code half the length of the block size of the cipher, with the CFB mode set to 8 bits.
Parameters:
cipher - the cipher to be used as the basis of the MAC generation.
padding - the padding to be used.

Method Details

doFinal

public int doFinal(byte[] out,
                   int outOff)
Specified by:
doFinal in interface Mac

getAlgorithmName

public String getAlgorithmName()
Specified by:
getAlgorithmName in interface Mac

getMacSize

public int getMacSize()
Specified by:
getMacSize in interface Mac

init

public void init(CipherParameters params)
Specified by:
init in interface Mac

reset

public void reset()
Reset the mac generator.
Specified by:
reset in interface Mac

update

public void update(byte in)
Specified by:
update in interface Mac

update

public void update(byte[] in,
                   int inOff,
                   int len)
Specified by:
update in interface Mac