Top Description Fields Constructors Methods
org.bouncycastle.crypto.engines

public Class NaccacheSternEngine

extends Object
implements AsymmetricBlockCipher
Class Inheritance
All Implemented Interfaces
org.bouncycastle.crypto.AsymmetricBlockCipher
Imports
java.math.BigInteger, java.util.Vector, org.bouncycastle.crypto.AsymmetricBlockCipher, .CipherParameters, .CryptoServicesRegistrar, .DataLengthException, .InvalidCipherTextException, org.bouncycastle.crypto.constraints.ConstraintUtils, .DefaultServiceProperties, org.bouncycastle.crypto.params.NaccacheSternKeyParameters, .NaccacheSternPrivateKeyParameters, .ParametersWithRandom, org.bouncycastle.util.Arrays
NaccacheStern Engine. For details on this cipher, please see https://www.gemplus.com/smart/rd/publications/pdf/NS98pkcs.pdf

Field Summary

Modifier and TypeField and Description
private boolean
debug

private boolean
forEncryption

private NaccacheSternKeyParameters
key

private Vector<E>[]
lookup

private static BigInteger
ONE

private static BigInteger
ZERO

Constructor Summary

AccessConstructor and Description
public
NaccacheSternEngine()

Method Summary

Modifier and TypeMethod and Description
public byte[]

Returns:

encrypt((block1 + block2) mod sigma)
addCryptedBlocks(byte[]
the first encrypted block
block1, byte[]
the second encrypted block
block2)

Adds the contents of two encrypted blocks mod sigma

private static BigInteger

Returns:

an integer x for that x % p_i == c_i
chineseRemainder(Vector<E>
the congruences c_i
congruences, Vector<E>
the primes p_i
primes)

Computes the integer x that is expressed through the given primes and the congruences with the chinese remainder theorem (CRT).

public byte[]

Returns:

The byte[] representation of the encrypted BigInteger (i.e. crypted.toByteArray())
encrypt(BigInteger
The BigInteger to encrypt
plain)

Encrypts a BigInteger aka Plaintext with the public key.

public int
getInputBlockSize()

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.getInputBlockSize.

Returns the input block size of this algorithm.
public int
getOutputBlockSize()

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.getOutputBlockSize.

Returns the output block size of this algorithm.
public void
init(boolean
if true the cipher is initialised for encryption, if false for decryption.
forEncryption, CipherParameters
the key and other data required by the cipher.
param)

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.init.

Initializes this algorithm.
public byte[]
processBlock(byte[]
the input data
in, int
offset into the in array where the data starts
inOff, int
the length of the block to be processed.
len)

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

Process a single Block using the Naccache-Stern algorithm.
public byte[]

Returns:

the data after it went through the NaccacheSternEngine.
processData(byte[]
the data to be processed
data)

Convenience Method for data exchange with the cipher.

public void
setDebug(boolean debug)

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

debugback to summary
private boolean debug
forEncryptionback to summary
private boolean forEncryption
keyback to summary
private NaccacheSternKeyParameters key
lookupback to summary
private Vector<E>[] lookup
ONEback to summary
private static BigInteger ONE
ZEROback to summary
private static BigInteger ZERO

Constructor Detail

NaccacheSternEngineback to summary
public NaccacheSternEngine()

Method Detail

addCryptedBlocksback to summary
public byte[] addCryptedBlocks(byte[] block1, byte[] block2) throws InvalidCipherTextException

Adds the contents of two encrypted blocks mod sigma

Parameters
block1:byte[]

the first encrypted block

block2:byte[]

the second encrypted block

Returns:byte[]

encrypt((block1 + block2) mod sigma)

chineseRemainderback to summary
private static BigInteger chineseRemainder(Vector<E> congruences, Vector<E> primes)

Computes the integer x that is expressed through the given primes and the congruences with the chinese remainder theorem (CRT).

Parameters
congruences:Vector<E>

the congruences c_i

primes:Vector<E>

the primes p_i

Returns:BigInteger

an integer x for that x % p_i == c_i

encryptback to summary
public byte[] encrypt(BigInteger plain)

Encrypts a BigInteger aka Plaintext with the public key.

Parameters
plain:BigInteger

The BigInteger to encrypt

Returns:byte[]

The byte[] representation of the encrypted BigInteger (i.e. crypted.toByteArray())

getInputBlockSizeback to summary
public int getInputBlockSize()

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.getInputBlockSize.

Returns the input block size of this algorithm.

Returns:int

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.getInputBlockSize.

maximum size for an input block.

See Also
org.bouncycastle.crypto.AsymmetricBlockCipher#getInputBlockSize()
getOutputBlockSizeback to summary
public int getOutputBlockSize()

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.getOutputBlockSize.

Returns the output block size of this algorithm.

Returns:int

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.getOutputBlockSize.

maximum size of the output block produced by the cipher.

See Also
org.bouncycastle.crypto.AsymmetricBlockCipher#getOutputBlockSize()
initback to summary
public void init(boolean forEncryption, CipherParameters param)

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.init.

Initializes this algorithm. Must be called before all other Functions.

Parameters
forEncryption:boolean

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.init.

if true the cipher is initialised for encryption, if false for decryption.

param:CipherParameters

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.init.

the key and other data required by the cipher.

See Also
org.bouncycastle.crypto.AsymmetricBlockCipher#init(boolean, org.bouncycastle.crypto.CipherParameters)
processBlockback to summary
public byte[] processBlock(byte[] in, int inOff, int len) throws InvalidCipherTextException

Implements org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

Process a single Block using the Naccache-Stern algorithm.

Parameters
in:byte[]

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

the input data

inOff:int

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

offset into the in array where the data starts

len:int

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

the length of the block to be processed.

Returns:byte[]

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

the resulting byte array of the encryption/decryption process.

Exceptions
InvalidCipherTextException:

Doc from org.bouncycastle.crypto.AsymmetricBlockCipher.processBlock.

data decrypts improperly.

See Also
org.bouncycastle.crypto.AsymmetricBlockCipher#processBlock(byte[], int, int)
processDataback to summary
public byte[] processData(byte[] data) throws InvalidCipherTextException

Convenience Method for data exchange with the cipher. Determines blocksize and splits data to blocksize.

Parameters
data:byte[]

the data to be processed

Returns:byte[]

the data after it went through the NaccacheSternEngine.

setDebugback to summary
public void setDebug(boolean debug)