org.logi.crypto.modes
Class DecryptCFB

java.lang.Object
  |
  +--org.logi.crypto.Crypto
        |
        +--org.logi.crypto.modes.DecryptMode
              |
              +--org.logi.crypto.modes.DecryptCFB

All Implemented Interfaces:

DecryptSession

public class DecryptCFB

extends org.logi.crypto.modes.DecryptMode

Use this class to decrypt ciphertext generated by EncryptCFB.

Note that unlike ECB or CBC mode, CFB mode uses the same key to encrypt and decrypt, even with asymmetric ciphers.

Author:

Logi Ragnarsson (logir@logi.org)

See Also:

EncryptCFB

Fields inherited from class org.logi.crypto.Crypto

BIT, cdsPath, EMPTY_ARRAY, FOUR, keySource, NIBBLE, ONE, primeCertainty, random, TWO, ZERO

Constructor Summary

DecryptCFB()
Create a new CFB-mode decrypt session with no key.

DecryptCFB(DecryptionKey key)
Create a new CFB-mode decrypt session with the specified key.

Method Summary

byte[]	decrypt(byte[] source, int i, int length) Send bytes to the DecryptCFB object for encryption.
byte[]	flush() Flush any buffers internal to the DecryptSession object and releases any and all resources.
byte[]	flush(byte[] source, int i, int length) Decrypt the last part of ciphertext and return plaintext.
DecryptionKey	getKey() Return the key used for decryption.
int	plainBlockSize() Return the size of the blocks of plaintext output by this object.
void	setKey(DecryptionKey key) Set the key to use for decryption.

Methods inherited from class org.logi.crypto.Crypto

binString, binString, ensureArrayLength, ensureArrayLength, equal, equalRelaxed, equalSub, fromHexNibble, fromHexString, fromString, fromString, hexString, hexString, hexString, hexString, hexString, initRandom, initRandom, makeClass, makeInt, makeLong, makeSessionKey, pastSpace, pickBits, pickBits, prettyPrint, prettyPrint, readBlock, readInt, trimArrayLength, trimArrayLength, trimLeadingZeroes, writeBytes, writeBytes, writeInt

Methods inherited from class java.lang.Object

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

Constructor Detail

DecryptCFB

public DecryptCFB(DecryptionKey key)
           throws KeyException

Create a new CFB-mode decrypt session with the specified key.

Throws:

KeyException - if key is a public key.

DecryptCFB

public DecryptCFB()

Create a new CFB-mode decrypt session with no key. No decryption can be performed until a call to setKey() has been made.

Method Detail

getKey

public DecryptionKey getKey()

Return the key used for decryption.

setKey

public void setKey(DecryptionKey key)
            throws KeyException

Set the key to use for decryption.

Throws:

KeyException - if key is a public key.

plainBlockSize

public int plainBlockSize()

Return the size of the blocks of plaintext output by this object.

decrypt

public byte[] decrypt(byte[] source,
                      int i,
                      int length)

Send bytes to the DecryptCFB object for encryption.

Decrypt length bytes from source, starting at i and return the plaintext.

flush

public byte[] flush()

Description copied from interface: DecryptSession

Flush any buffers internal to the DecryptSession object and releases any and all resources.

flush

public byte[] flush(byte[] source,
                    int i,
                    int length)
             throws CryptoException

Decrypt the last part of ciphertext and return plaintext. This will flush any buffers internal to the DecryptSession object.

Specified by:

flush in interface DecryptSession