Package org.bouncycastle.crypto.modes

Class PGPCFBBlockCipher

  • All Implemented Interfaces:
    BlockCipher
    public class PGPCFBBlockCipher
extends java.lang.Object
implements BlockCipher
    Implements OpenPGP's rather strange version of Cipher-FeedBack (CFB) mode on top of a simple cipher. For further info see RFC 2440.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.String getAlgorithmName()
      return the algorithm name and mode.
      int getBlockSize()
      return the block size we are operating at.
      BlockCipher getUnderlyingCipher()
      return the underlying block cipher that we are wrapping.
      void init​(boolean forEncryption, CipherParameters params)
      Initialise the cipher and, possibly, the initialisation vector (IV).
      int processBlock​(byte[] in, int inOff, byte[] out, int outOff)
      Process one block of input from the array in and write it to the out array.
      void reset()
      reset the chaining vector back to the IV and reset the underlying cipher.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • PGPCFBBlockCipher

        public PGPCFBBlockCipher​(BlockCipher cipher,
                         boolean inlineIv)
        Basic constructor.
        Parameters:
        cipher - the block cipher to be used as the basis of the feedback mode.
        inlineIv - if true this is for PGP CFB with a prepended iv.

    • Method Detail

      • getUnderlyingCipher

        public BlockCipher getUnderlyingCipher()
        return the underlying block cipher that we are wrapping.
        Returns:
        the underlying block cipher that we are wrapping.

      • getAlgorithmName

        public java.lang.String getAlgorithmName()
        return the algorithm name and mode.
        Specified by:
        getAlgorithmName in interface BlockCipher
        Returns:
        the name of the underlying algorithm followed by "/PGPCFB" and the block size in bits.

      • getBlockSize

        public int getBlockSize()
        return the block size we are operating at.
        Specified by:
        getBlockSize in interface BlockCipher
        Returns:
        the block size we are operating at (in bytes).

      • processBlock

        public int processBlock​(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        java.lang.IllegalStateException
        Process one block of input from the array in and write it to the out array.
        Specified by:
        processBlock in interface BlockCipher
        Parameters:
        in - the array containing the input data.
        inOff - offset into the in array the data starts at.
        out - the array the output data will be copied into.
        outOff - the offset into the out array the output will start at.
        Returns:
        the number of bytes processed and produced.
        Throws:
        DataLengthException - if there isn't enough data in in, or space in out.
        java.lang.IllegalStateException - if the cipher isn't initialised.

      • reset

        public void reset()
        reset the chaining vector back to the IV and reset the underlying cipher.
        Specified by:
        reset in interface BlockCipher

      • init

        public void init​(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
        Initialise the cipher and, possibly, the initialisation vector (IV). If an IV isn't passed as part of the parameter, the IV will be all zeros. An IV which is too short is handled in FIPS compliant fashion.
        Specified by:
        init in interface BlockCipher
        Parameters:
        forEncryption - if true the cipher is initialised for encryption, if false for decryption.
        params - the key and other data required by the cipher.
        Throws:
        java.lang.IllegalArgumentException - if the params argument is inappropriate.