File	Doc	Category	Size	Date	Package
BufferedAsymmetricBlockCipher.java	API Doc	Android 1.5 API	3869	Wed May 06 22:41:06 BST 2009	org.bouncycastle.crypto

BufferedAsymmetricBlockCipher

• java.lang.Object

Fields Summary
protected byte[]	buf
protected int	bufOff
private final AsymmetricBlockCipher	cipher

Constructors Summary
public BufferedAsymmetricBlockCipher(AsymmetricBlockCipher cipher) base constructor. param cipher the cipher this buffering object wraps. this.cipher = cipher;

Methods Summary
public byte[]	doFinal() process the contents of the buffer using the underlying cipher. return the result of the encryption/decryption process on the buffer. exception InvalidCipherTextException if we are given a garbage block. byte[] out = cipher.processBlock(buf, 0, bufOff); reset(); return out;
public int	getBufferPosition() return the amount of data sitting in the buffer. return the amount of data sitting in the buffer. return bufOff;
public int	getInputBlockSize() returns the largest size an input block can be. return maximum size for an input block. return cipher.getInputBlockSize();
public int	getOutputBlockSize() returns the maximum size of the block produced by this cipher. return maximum size of the output block produced by the cipher. return cipher.getOutputBlockSize();
public AsymmetricBlockCipher	getUnderlyingCipher() return the underlying cipher for the buffer. return the underlying cipher for the buffer. return cipher;
public void	init(boolean forEncryption, CipherParameters params) initialise the buffer and the underlying cipher. param forEncryption if true the cipher is initialised for encryption, if false for decryption. param params the key and other data required by the cipher. reset(); cipher.init(forEncryption, params); buf = new byte[cipher.getInputBlockSize()]; bufOff = 0;
public void	processByte(byte in) add another byte for processing. param in the input byte. if (bufOff > buf.length) { throw new DataLengthException("attempt to process message to long for cipher"); } buf[bufOff++] = in;
public void	processBytes(byte[] in, int inOff, int len) add len bytes to the buffer for processing. param in the input data param inOff offset into the in array where the data starts param len the length of the block to be processed. if (len == 0) { return; } if (len < 0) { throw new IllegalArgumentException("Can't have a negative input length!"); } if (bufOff + len > buf.length) { throw new DataLengthException("attempt to process message to long for cipher"); } System.arraycopy(in, inOff, buf, bufOff, len); bufOff += len;
public void	reset() Reset the buffer and the underlying cipher. /* * clean the buffer. */ if (buf != null) { for (int i = 0; i < buf.length; i++) { buf[0] = 0; } } bufOff = 0;