cryptix.provider.cipher
public final class SAFER extends Cipher implements SymmetricCipher
SAFER (Secure And Fast Encryption Routine) is a block-cipher algorithm developed by Prof. J.L. Massey at the Swiss Federal Institute of Technology. SAFER is usable in four versions (referred to in this implementation as VARIANTS): SAFER K-64, SAFER K-128, SAFER SK-64 and SAFER SK-128. The numerals 64 and 128 stand for the length of the user-selected key, 'K' stands for the original key schedule and 'SK' stands for the strengthened key schedule.
References:
Ported to Java from public domain 'C' code latest revised on September 9, 1995 by:
Richard De Moliner (demoliner@isi.ee.ethz.ch)
Signal and Information Processing Laboratory
Swiss Federal Institute of Technology
CH-8092 Zürich, Switzerland.
Copyright © 1997
Systemics Ltd on behalf of the
Cryptix Development Team.
All rights reserved.
$Revision: 1.8 $
Since: Cryptix 2.2.2
Field Summary | |
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static int | K128_VARIANT |
static int | K64_VARIANT |
static int | SK128_VARIANT |
static int | SK64_VARIANT |
Constructor Summary | |
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SAFER()
Calls the Cipher constructor with implBuffering false,
implPadding false and the provider set to "Cryptix".
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Method Summary | |
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Object | clone()
Always throws a CloneNotSupportedException (cloning of ciphers is not
supported for security reasons). |
int | engineBlockSize()
SPI: Returns the length of an input block, in bytes.
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protected Object | engineGetParameter(String param) |
void | engineInitDecrypt(Key key)
SPI: Initializes this cipher for decryption, using the
specified key.
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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) |
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. |
static LinkStatus | getLinkStatus()
Gets an object representing the native linking status of this class. |
int | getRounds()
Gets the number of rounds for this cipher. |
String | getVariant()
Gets the variant for this cipher ("SK-128", "SK-64", "K-128", or "K-64"). |
void | setRounds(int rounds)
Sets the number of rounds for this cipher. |
void | setVariant(String ps)
Sets the variant for this cipher. |
implBuffering
false,
implPadding
false and the provider set to "Cryptix".
Sets the variant of this cipher based on the currently set "variant" property in the provider properties file. The current JCE syntax for the SAFER algorithm variant property is:
Alg.variant.SAFER = ...
Valid alternatives for variant are:
Once the variant is set, a default value for the number of rounds to use is also set as follows:
Variant Number of rounds = current value ------- -------------------------------- SK-128 SK128_DEFAULT_NOF_ROUNDS = 10 SK-64 SK64_DEFAULT_NOF_ROUNDS = 8 K-128 K128_DEFAULT_NOF_ROUNDS = 10 K-64 K64_DEFAULT_NOF_ROUNDS = 6
If no variant property is found in the provider's properties file a strengthened key schedule of 128 bits is used with 10 rounds.
This constructor also attempts to set the desired number of rounds for this cipher object from a "rounds" property in the provider's properties file. Acceptable values are non-zero integers between 1 and the MAX_NOF_ROUNDS constant; i.e. 13. If no such property is found, or is found but deemed invalid, then the already set value (depending on the variant property as determined above) remains unaltered.
Returns: the length in bytes of an input block for this cipher.
Parameters: key the key to use for decryption.
Throws: KeyException if the key is invalid.
Parameters: key the key to use for encryption.
Throws: KeyException if the key is invalid.
in and out may be the same array, and the input and output regions may overlap.
Parameters: 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.
Returns: the number of bytes written.
Throws: CryptixException if the native library is being used, and it reports an error.
If the specified number is invalid, the current one remains unchanged.
Parameters: rounds the desired number of rounds for this cipher.
UNKNOWN: IllegalStateException if this cipher is not uninitialised.
Parameters: ps The desired new variant identifier for this cipher.
UNKNOWN: IllegalStateException If this cipher is not uninitialised. InvalidParameterException If the variant identifier is invalid.