cryptix.provider.cipher
Class Blowfish
- Parameterized, SymmetricCipher
public final class Blowfish
This class implements the Blowfish block cipher.
Blowfish was designed by
Bruce
Schneier. The algorithm is in the public domain.
References:
- Bruce Schneier,
"Section 14.3 Blowfish,"
Applied Cryptography, 2nd edition,
John Wiley & Sons, 1996
- Bruce Schneier,
"Description of a New Variable-Length Key, 64-Bit Cipher (Blowfish),"
Fast Software Encryption Cambridge Security Workshop Proceedings,
Springer-Verlag, 1004, pp 191-204.
Copyright © 1997
Systemics Ltd on behalf of the
Cryptix Development Team.
All rights reserved.
$Revision: 1.8 $
- Systemics Ltd
- David Hopwood
- Raif S. Naffah
- Cryptix 2.2
Blowfish() - Constructs a Blowfish cipher object, in the UNINITIALIZED state.
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Object | clone() - Always throws a CloneNotSupportedException (cloning of ciphers is not
supported for security reasons).
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protected int | engineBlockSize() - SPI: Returns the length of an input block, in bytes.
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protected Object | engineGetParameter(String param) - SPI: Gets the value of the specified algorithm parameter.
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protected void | engineInitDecrypt(Key key) - SPI: Initializes this cipher for decryption, using the
specified key.
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protected void | engineInitEncrypt(Key key) - SPI: Initializes this cipher for encryption, using the
specified key.
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protected void | engineSetParameter(String param, Object value) - SPI: Sets the specified algorithm parameter to the specified
value.
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protected int | engineUpdate(byte[] in, int inOffset, int inLen, byte[] out, int outOffset) - SPI: This is the main engine method for updating data.
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protected void | finalize() - Cleans up resources used by this instance, if necessary.
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static LinkStatus | getLinkStatus() - Gets an object representing the native linking status of this class.
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int | getRounds() - Returns the currently set number of rounds for this instance.
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static void | main(String[] args) - Entry point for very basic
self_test .
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void | setRounds(int r) - Sets the number of rounds for this cipher.
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blockSize , clone , crypt , crypt , crypt , doFinal , doFinal , doFinal , doFinal , engineBlockSize , engineCiphertextBlockSize , engineCrypt , engineGetParameter , engineInBufferSize , engineInitDecrypt , engineInitEncrypt , engineOutBufferSize , enginePlaintextBlockSize , engineSetPaddingScheme , engineSetParameter , engineUpdate , getAlgorithm , getAlgorithms , getAlgorithms , getCiphertextBlockSize , getInputBlockSize , getInstance , getInstance , getInstance , getMode , getOutputBlockSize , getPadding , getPaddingScheme , getParameter , getPlaintextBlockSize , getProvider , getState , inBufferSize , inBufferSizeFinal , initDecrypt , initEncrypt , isPaddingBlockCipher , outBufferSize , outBufferSizeFinal , setParameter , toString , update , update , update , update |
Blowfish
public Blowfish()
Constructs a Blowfish cipher object, in the UNINITIALIZED state.
This calls the Cipher constructor with
implBuffering false,
implPadding false and the provider set to "Cryptix".
We define a "rounds" property to allow running the algorithm in a number
of rounds different than the default value; i.e. 16.
Note however that there is not enough defined initial data for any
number of rounds other than 16 for the time being.
clone
public final Object clone()
throws CloneNotSupportedException
Always throws a CloneNotSupportedException (cloning of ciphers is not
supported for security reasons).
- clone in interface Cipher
engineBlockSize
protected int engineBlockSize()
SPI: Returns the length of an input block, in bytes.
- engineBlockSize in interface Cipher
- the length in bytes of an input block for this cipher.
engineGetParameter
protected Object engineGetParameter(String param)
SPI: Gets the value of the specified algorithm parameter.
Blowfish has a single parameter, "rounds", which specifies the
number of rounds for this instance as a decimal String.
- engineGetParameter in interface Cipher
param
- the string name of the parameter.
- the object that represents the parameter value, or null if there
is none.
engineInitDecrypt
protected void engineInitDecrypt(Key key)
throws InvalidKeyException,
CryptixException
SPI: Initializes this cipher for decryption, using the
specified key.
- engineInitDecrypt in interface Cipher
key
- the key to use for decryption.
CryptixException
- if any one of the two self-tests fail.
The two self-tests are as follows:
- encrypt 0 ten times using the initial S and P boxes
values. Check the result against a known value. If equal
decrypt the result 10 times and compare it to 0;
- complete the key expansion process and use the newly
formed key to encrypt 10 times 0; decrypt the result 10
times and compare.
engineInitEncrypt
protected void engineInitEncrypt(Key key)
throws InvalidKeyException,
CryptixException
SPI: Initializes this cipher for encryption, using the
specified key.
- engineInitEncrypt in interface Cipher
key
- the key to use for encryption.
CryptixException
- if any one of the two self-tests fail.
The two self-tests are as follows:
- encrypt 0 ten times using the initial S and P boxes
values. Check the result against a known value. If equal
decrypt the result 10 times and compare it to 0;
- complete the key expansion process and use the newly
formed key to encrypt 10 times 0; decrypt the result 10
times and compare.
engineSetParameter
protected void engineSetParameter(String param,
Object value)
throws InvalidParameterException,
InvalidParameterTypeException
SPI: Sets the specified algorithm parameter to the specified
value.
Blowfish has a single parameter, "rounds", which specifies the
number of rounds for this instance as a decimal String.
- engineSetParameter in interface Cipher
param
- the string name of the parameter.value
- the parameter value.
InvalidParameterTypeException
- if value is of the wrong
type.
engineUpdate
protected int engineUpdate(byte[] in,
int inOffset,
int inLen,
byte[] out,
int outOffset)
SPI: This is the main engine method for updating data.
in and
out may be the same array, and the input and output
regions may overlap.
- engineUpdate in interface Cipher
in
- the input data.inOffset
- the offset into in specifying where the data starts.inLen
- the length of the subarray.out
- the output array.outOffset
- the offset indicating where to start writing into
the out array.
- the number of bytes written.
finalize
protected final void finalize()
Cleans up resources used by this instance, if necessary.
getLinkStatus
public static LinkStatus getLinkStatus()
Gets an object representing the native linking status of this class.
getRounds
public int getRounds()
Returns the currently set number of rounds for this instance.
- the number of rounds.
main
public static void main(String[] args)
Entry point for very basic self_test
.
setRounds
public void setRounds(int r)
Sets the number of rounds for this cipher. Allowed only when this
cipher is in the UNINITIALIZED state; otherwise an exception is
thrown.
If the specified number is invalid, an IllegalArgumentException is
thrown.
Note that there is not enough defined initial data for any number
of rounds other than 16 for the time being.
r
- the desired number of rounds for this cipher.