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java.lang.Objectgnu.crypto.cipher.BaseCipher
gnu.crypto.cipher.Twofish
public final class Twofish
Twofish is a balanced 128-bit Feistel cipher, consisting of 16 rounds. In each round, a 64-bit S-box value is computed from 64 bits of the block, and this value is xored into the other half of the block. The two half-blocks are then exchanged, and the next round begins. Before the first round, all input bits are xored with key-dependent "whitening" subkeys, and after the final round the output bits are xored with other key-dependent whitening subkeys; these subkeys are not used anywhere else in the algorithm.
Twofish is designed by Bruce Schneier, Doug Whiting, John Kelsey, Chris Hall, David Wagner and Niels Ferguson.
References:
Field Summary |
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Fields inherited from class gnu.crypto.cipher.BaseCipher |
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currentBlockSize, currentKey, defaultBlockSize, defaultKeySize, lock, name |
Fields inherited from interface gnu.crypto.cipher.IBlockCipher |
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CIPHER_BLOCK_SIZE, KEY_MATERIAL |
Constructor Summary | |
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Twofish()
Trivial 0-arguments constructor. |
Method Summary | |
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Iterator |
blockSizes()
Returns an Iterator over the supported block sizes. |
Object |
clone()
Returns a clone of this instance. |
void |
decrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
Object sessionKey,
int bs)
|
void |
encrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
Object sessionKey,
int bs)
|
Iterator |
keySizes()
Returns an Iterator over the supported key sizes. |
Object |
makeKey(byte[] k,
int bs)
Expands a user-supplied key material into a session key for a designated block size. |
boolean |
selfTest()
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT). |
Methods inherited from class gnu.crypto.cipher.BaseCipher |
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currentBlockSize, decryptBlock, defaultBlockSize, defaultKeySize, encryptBlock, init, name, reset, testKat, testKat |
Methods inherited from class java.lang.Object |
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equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public Twofish()
Method Detail |
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public Object clone()
IBlockCipher
Returns a clone of this instance.
clone
in interface IBlockCipher
clone
in class BaseCipher
public Iterator blockSizes()
IBlockCipher
Returns an Iterator
over the supported block sizes. Each
element returned by this object is an Integer
.
Iterator
over the supported block sizes.public Iterator keySizes()
IBlockCipher
Returns an Iterator
over the supported key sizes. Each element
returned by this object is an Integer
.
Iterator
over the supported key sizes.public Object makeKey(byte[] k, int bs) throws InvalidKeyException
Expands a user-supplied key material into a session key for a designated block size.
k
- the 64/128/192/256-bit user-key to use.bs
- the desired block size in bytes.
IllegalArgumentException
- if the block size is not 16 (128-bit).
InvalidKeyException
- if the key data is invalid.public void encrypt(byte[] in, int inOffset, byte[] out, int outOffset, Object sessionKey, int bs)
public void decrypt(byte[] in, int inOffset, byte[] out, int outOffset, Object sessionKey, int bs)
public boolean selfTest()
IBlockCipher
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).
selfTest
in interface IBlockCipher
selfTest
in interface IBlockCipherSpi
selfTest
in class BaseCipher
true
if the implementation passes simple
correctness tests. Returns false
otherwise.
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For the latest news and information visit The GNU Crypto project |
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