org.bouncycastle.crypto.encodings
Class PKCS1Encoding

java.lang.Object
  org.bouncycastle.crypto.encodings.PKCS1Encoding

All Implemented Interfaces:

AsymmetricBlockCipher

public class PKCS1Encoding
extends java.lang.Object
implements AsymmetricBlockCipher

this does your basic PKCS 1 v1.5 padding - whether or not you should be using this depends on your application - see PKCS1 Version 2 for details.

Field Summary

private AsymmetricBlockCipher	engine
private boolean	forEncryption
private boolean	forPrivateKey
private static int	HEADER_LENGTH
private java.security.SecureRandom	random
static java.lang.String	STRICT_LENGTH_ENABLED_PROPERTY some providers fail to include the leading zero in PKCS1 encoded blocks.
private boolean	useStrictLength

Constructor Summary

PKCS1Encoding(AsymmetricBlockCipher cipher)
Basic constructor.

Method Summary

private byte[]	decodeBlock(byte[] in, int inOff, int inLen)
private byte[]	encodeBlock(byte[] in, int inOff, int inLen)
int	getInputBlockSize() returns the largest size an input block can be.
int	getOutputBlockSize() returns the maximum size of the block produced by this cipher.
void	init(boolean forEncryption, CipherParameters param) initialise the cipher.
byte[]	processBlock(byte[] in, int inOff, int inLen) process the block of len bytes stored in in from offset inOff.
private boolean	useStrict()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

STRICT_LENGTH_ENABLED_PROPERTY

public static final java.lang.String STRICT_LENGTH_ENABLED_PROPERTY

some providers fail to include the leading zero in PKCS1 encoded blocks. If you need to work with one of these set the system property org.bouncycastle.pkcs1.strict to false.

The system property is checked during construction of the encoding object, it is set to true by default.

See Also:

Constant Field Values

HEADER_LENGTH

private static final int HEADER_LENGTH

See Also:

Constant Field Values

random

private java.security.SecureRandom random

engine

private AsymmetricBlockCipher engine

forEncryption

private boolean forEncryption

forPrivateKey

private boolean forPrivateKey

useStrictLength

private boolean useStrictLength

Constructor Detail

PKCS1Encoding

public PKCS1Encoding(AsymmetricBlockCipher cipher)

Basic constructor.

Parameters:

cipher -

Method Detail

useStrict

private boolean useStrict()

init

public void init(boolean forEncryption,
                 CipherParameters param)

Description copied from interface: AsymmetricBlockCipher

initialise the cipher.

Specified by:

init in interface AsymmetricBlockCipher

Parameters:

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

param - the key and other data required by the cipher.

getInputBlockSize

public int getInputBlockSize()

Description copied from interface: AsymmetricBlockCipher

returns the largest size an input block can be.

Specified by:

getInputBlockSize in interface AsymmetricBlockCipher

Returns:

maximum size for an input block.

getOutputBlockSize

public int getOutputBlockSize()

Description copied from interface: AsymmetricBlockCipher

returns the maximum size of the block produced by this cipher.

Specified by:

getOutputBlockSize in interface AsymmetricBlockCipher

Returns:

maximum size of the output block produced by the cipher.

processBlock

public byte[] processBlock(byte[] in,
                           int inOff,
                           int inLen)
                    throws InvalidCipherTextException

Description copied from interface: AsymmetricBlockCipher

process the block of len bytes stored in in from offset inOff.

Specified by:

processBlock in interface AsymmetricBlockCipher

Parameters:

in - the input data

inOff - offset into the in array where the data starts

inLen - the length of the block to be processed.

Returns:

the resulting byte array of the encryption/decryption process.

Throws:

InvalidCipherTextException - data decrypts improperly.

encodeBlock

private byte[] encodeBlock(byte[] in,
                           int inOff,
                           int inLen)
                    throws InvalidCipherTextException

Throws:

InvalidCipherTextException

decodeBlock

private byte[] decodeBlock(byte[] in,
                           int inOff,
                           int inLen)
                    throws InvalidCipherTextException

Throws:

InvalidCipherTextException - if the decrypted block is not in PKCS1 format.