org.spongycastle.crypto.encodings

Class PKCS1Encoding

java.lang.Object

org.spongycastle.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

Fields

Modifier and Type	Field and Description
static java.lang.String	NOT_STRICT_LENGTH_ENABLED_PROPERTY some providers fail to include the leading zero in PKCS1 encoded blocks.
static java.lang.String	STRICT_LENGTH_ENABLED_PROPERTY Deprecated. use NOT_STRICT_LENGTH_ENABLED_PROPERTY

Constructor Summary

Constructors

Constructor and Description
PKCS1Encoding(AsymmetricBlockCipher cipher) Basic constructor.
PKCS1Encoding(AsymmetricBlockCipher cipher, byte[] fallback) Constructor for decryption with a fixed plaintext length and a fallback value that is returned, if the padding is incorrect.
PKCS1Encoding(AsymmetricBlockCipher cipher, int pLen) Constructor for decryption with a fixed plaintext length.

Method Summary

Modifier and Type	Method and Description
int	getInputBlockSize() returns the largest size an input block can be.
int	getOutputBlockSize() returns the maximum size of the block produced by this cipher.
AsymmetricBlockCipher	getUnderlyingCipher()
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.

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

Deprecated. use NOT_STRICT_LENGTH_ENABLED_PROPERTY

See Also:

Constant Field Values

NOT_STRICT_LENGTH_ENABLED_PROPERTY

public static final java.lang.String NOT_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.spongycastle.pkcs1.not_strict to true.

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

See Also:

Constant Field Values

Constructor Detail

PKCS1Encoding

public PKCS1Encoding(AsymmetricBlockCipher cipher)

Basic constructor.

Parameters:

cipher -

PKCS1Encoding

public PKCS1Encoding(AsymmetricBlockCipher cipher,
                     int pLen)

Constructor for decryption with a fixed plaintext length.

Parameters:

cipher - The cipher to use for cryptographic operation.

pLen - Length of the expected plaintext.

PKCS1Encoding

public PKCS1Encoding(AsymmetricBlockCipher cipher,
                     byte[] fallback)

Constructor for decryption with a fixed plaintext length and a fallback value that is returned, if the padding is incorrect.

Parameters:

cipher - The cipher to use for cryptographic operation.

fallback - The fallback value, we don't do an arraycopy here.

Method Detail

getUnderlyingCipher

public AsymmetricBlockCipher getUnderlyingCipher()

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.