Package org.bouncycastle.crypto

Class DefaultBufferedMultiBlockCipher

  • All Implemented Interfaces:
    BufferedBlockCipher
    Direct Known Subclasses:
    PaddedBufferedMultiBlockCipher
    public class DefaultBufferedMultiBlockCipher
extends java.lang.Object
implements BufferedBlockCipher
    A wrapper class that allows multi-block ciphers to be used to process data in a piecemeal fashion. The BufferedBlockCipher outputs a block only when the buffer is full and more data is being added, or on a doFinal.

    Note: in the case where the underlying cipher is either a CFB cipher or an OFB one the last block may not be a multiple of the block size.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int doFinal​(byte[] out, int outOff)
      Process the last block in the buffer.
      int getBlockSize()
      return the blocksize for the underlying cipher.
      int getOutputSize​(int length)
      return the size of the output buffer required for an update plus a doFinal with an input of 'length' bytes.
      BlockCipher getUnderlyingCipher()
      return the cipher this object wraps.
      int getUpdateOutputSize​(int len)
      return the size of the output buffer required for an update an input of len bytes.
      void init​(boolean forEncryption, CipherParameters params)
      initialise the cipher.
      int processByte​(byte in, byte[] out, int outOff)  
      int processBytes​(byte[] in, int inOff, int len, byte[] out, int outOff)
      process an array of bytes, producing output if necessary.
      void reset()
      Reset the buffer and cipher.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • buf

        protected byte[] buf

      • bufOff

        protected int bufOff

      • forEncryption

        protected boolean forEncryption

      • partialBlockOkay

        protected boolean partialBlockOkay

      • pgpCFB

        protected boolean pgpCFB

      • blockSize

        protected int blockSize

    • Constructor Detail

      • DefaultBufferedMultiBlockCipher

        public DefaultBufferedMultiBlockCipher​(MultiBlockCipher cipher)
        Create a buffered block cipher without padding.
        Parameters:
        cipher - the underlying block cipher this buffering object wraps.

    • Method Detail

      • init

        public void init​(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
        initialise the cipher.
        Specified by:
        init in interface BufferedBlockCipher
        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.

      • getBlockSize

        public int getBlockSize()
        return the blocksize for the underlying cipher.
        Specified by:
        getBlockSize in interface BufferedBlockCipher
        Returns:
        the blocksize for the underlying cipher.

      • getUpdateOutputSize

        public int getUpdateOutputSize​(int len)
        return the size of the output buffer required for an update an input of len bytes.
        Specified by:
        getUpdateOutputSize in interface BufferedBlockCipher
        Parameters:
        len - the length of the input.
        Returns:
        the space required to accommodate a call to update with len bytes of input.

      • getOutputSize

        public int getOutputSize​(int length)
        return the size of the output buffer required for an update plus a doFinal with an input of 'length' bytes.
        Specified by:
        getOutputSize in interface BufferedBlockCipher
        Parameters:
        length - the length of the input.
        Returns:
        the space required to accommodate a call to update and doFinal with 'length' bytes of input.

      • processBytes

        public int processBytes​(byte[] in,
                        int inOff,
                        int len,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        java.lang.IllegalStateException
        process an array of bytes, producing output if necessary.
        Specified by:
        processBytes in interface BufferedBlockCipher
        Parameters:
        in - the input byte array.
        inOff - the offset at which the input data starts.
        len - the number of bytes to be copied out of the input array.
        out - the space for any output that might be produced.
        outOff - the offset from which the output will be copied.
        Returns:
        the number of output bytes copied to out.
        Throws:
        DataLengthException - if there isn't enough space in out.
        java.lang.IllegalStateException - if the cipher isn't initialised.

      • doFinal

        public int doFinal​(byte[] out,
                   int outOff)
            throws DataLengthException,
                   java.lang.IllegalStateException,
                   InvalidCipherTextException
        Process the last block in the buffer.
        Specified by:
        doFinal in interface BufferedBlockCipher
        Parameters:
        out - the array the block currently being held is copied into.
        outOff - the offset at which the copying starts.
        Returns:
        the number of output bytes copied to out.
        Throws:
        DataLengthException - if there is insufficient space in out for the output, or the input is not block size aligned and should be.
        java.lang.IllegalStateException - if the underlying cipher is not initialised.
        InvalidCipherTextException - if padding is expected and not found.
        DataLengthException - if the input is not block size aligned.

      • reset

        public void reset()
        Reset the buffer and cipher. After resetting the object is in the same state as it was after the last init (if there was one).
        Specified by:
        reset in interface BufferedBlockCipher

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object