org.bouncycastle.crypto.macs

Class CFBBlockCipherMac

public class CFBBlockCipherMac extends Object implements Mac

Constructor Summary
CFBBlockCipherMac(BlockCipher cipher)
create a standard MAC based on a CFB block cipher.
CFBBlockCipherMac(BlockCipher cipher, BlockCipherPadding padding)
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.
Method Summary
intdoFinal(byte[] out, int outOff)
StringgetAlgorithmName()
intgetMacSize()
voidinit(CipherParameters params)
voidreset()
Reset the mac generator.
voidupdate(byte in)
voidupdate(byte[] in, int inOff, int len)

Constructor Detail

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, 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.

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.

Method Detail

doFinal

public int doFinal(byte[] out, int outOff)

getAlgorithmName

public String getAlgorithmName()

getMacSize

public int getMacSize()

init

public void init(CipherParameters params)

reset

public void reset()
Reset the mac generator.

update

public void update(byte in)

update

public void update(byte[] in, int inOff, int len)