File	Doc	Category	Size	Date	Package
DES_CBC.java	API Doc	phoneME MR2 API (J2ME)	5333	Wed May 02 18:00:00 BST 2007	com.sun.midp.crypto

DES_CBC

• java.lang.Object
  • DES_ECB

Fields Summary
private byte[]	chainingBlock Internal data.
private byte[]	storeBuffer Internal data.
private byte[]	savedChainingBlock Saved state variable.

Constructors Summary
public DES_CBC(boolean useTripleDes) Constructor. param useTripleDes true if the class is being used for triple DES super(useTripleDes); chainingBlock = new byte[BLOCK_SIZE]; storeBuffer = new byte[BLOCK_SIZE];

Methods Summary
public int	doFinal(byte[] inBuff, int inOffset, int inLength, byte[] outBuff, int outOffset) Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation. The data is encrypted or decrypted, depending on how this cipher was initialized. param inBuff the input buffer param inOffset the offset in input where the input starts param inLength the input length param outBuff the buffer for the result param outOffset the offset in output where the result is stored return the number of bytes stored in output exception IllegalStateException if this cipher is in a wrong state (e.g., has not been initialized) exception javax.crypto.IllegalBlockSizeException if this cipher is a block cipher, no padding has been requested (only in encryption mode), and the total input length of the data processed by this cipher is not a multiple of block size exception javax.crypto.ShortBufferException if the given output buffer is too small to hold the result exception javax.crypto.BadPaddingException if this cipher is int decryption mode, and (un)padding has been requested, but the decrypted data is not bounded by the appropriate padding bytes int result = super.doFinal(inBuff, inOffset, inLength, outBuff, outOffset); System.arraycopy(IV, 0, chainingBlock, 0, BLOCK_SIZE); return result;
public void	init(int mode, Key key, CryptoParameter params) Initializes this cipher with a key and a set of algorithm parameters. param mode the operation mode of this cipher param key the encryption key param params the algorithm parameters exception java.security.InvalidKeyException if the given key is inappropriate for initializing this cipher exception java.security.InvalidAlgorithmParameterException if the given algorithm parameters are inappropriate for this cipher doInit(mode, keyAlgorithm, key, true, params); System.arraycopy(IV, 0, chainingBlock, 0, BLOCK_SIZE);
protected void	processBlock(byte[] out, int offset) Depending on the mode, either encrypts or decrypts data block. param out will contain the result of encryption or decryption operation param offset is the offset in out if (mode == Cipher.ENCRYPT_MODE) { Util.xorArrays(holdData, chainingBlock); super.processBlock(out, offset); System.arraycopy(out, offset, chainingBlock, 0, BLOCK_SIZE); } else { System.arraycopy(holdData, 0, storeBuffer, 0, BLOCK_SIZE); super.processBlock(out, offset); for (int i = 0; i < BLOCK_SIZE; i++) { out[offset + i] ^= chainingBlock[i]; } System.arraycopy(storeBuffer, 0, chainingBlock, 0, BLOCK_SIZE); }
protected void	restoreState() Restores cipher state. super.restoreState(); chainingBlock = savedChainingBlock;
protected void	saveState() Saves cipher state. super.saveState(); savedChainingBlock = Util.cloneArray(chainingBlock);