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java.lang.Object
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+--gnu.crypto.cipher.BaseCipher
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+--gnu.crypto.cipher.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 |
| Fields inherited from class gnu.crypto.cipher.BaseCipher |
currentBlockSize, currentKey, defaultBlockSize, defaultKeySize, lock, name |
| Fields inherited from interface gnu.crypto.cipher.IBlockCipher |
CIPHER_BLOCK_SIZE, KEY_MATERIAL |
| Constructor Summary | |
Twofish()
Trivial 0-arguments constructor. |
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| Method Summary | |
java.util.Iterator |
blockSizes()
Returns an Iterator over the supported block sizes. |
java.lang.Object |
clone()
Returns a clone of this instance. |
void |
decrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
java.lang.Object sessionKey,
int bs)
Decrypts exactly one block of ciphertext. |
void |
encrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
java.lang.Object sessionKey,
int bs)
Encrypts exactly one block of plaintext. |
java.util.Iterator |
keySizes()
Returns an Iterator over the supported key sizes. |
java.lang.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 |
currentBlockSize, decryptBlock, defaultBlockSize, defaultKeySize, encryptBlock, init, name, reset, testKat |
| Methods inherited from class java.lang.Object |
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
public Twofish()
| Method Detail |
public java.lang.Object clone()
IBlockCipherReturns a clone of this instance.
clone in interface IBlockCipherclone in class BaseCipherpublic java.util.Iterator blockSizes()
IBlockCipherReturns an Iterator over the supported block sizes. Each
element returned by this object is an Integer.
Iterator over the supported block sizes.public java.util.Iterator keySizes()
IBlockCipherReturns an Iterator over the supported key sizes. Each element
returned by this object is an Integer.
Iterator over the supported key sizes.
public java.lang.Object makeKey(byte[] k,
int bs)
throws java.security.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.
java.lang.IllegalArgumentException - if the block size is not 16 (128-bit).
java.security.InvalidKeyException - if the key data is invalid.
public void encrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
java.lang.Object sessionKey,
int bs)
IBlockCipherSpiEncrypts exactly one block of plaintext.
in - the plaintext.inOffset - index of in from which to start considering
data.out - the ciphertext.outOffset - index of out from which to store the result.sessionKey - the session key to use.bs - the block size to use.
public void decrypt(byte[] in,
int inOffset,
byte[] out,
int outOffset,
java.lang.Object sessionKey,
int bs)
IBlockCipherSpiDecrypts exactly one block of ciphertext.
in - the ciphertext.inOffset - index of in from which to start considering
data.out - the plaintext.outOffset - index of out from which to store the result.sessionKey - the session key to use.bs - the block size to use.public boolean selfTest()
IBlockCipherA 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 IBlockCipherselfTest in class BaseCiphertrue 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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