Package org.bouncycastle.crypto

Class DefaultBufferedBlockCipher

java.lang.Object
org.bouncycastle.crypto.DefaultBufferedBlockCipher
All Implemented Interfaces:
BufferedBlockCipher
Direct Known Subclasses:
CTSBlockCipher, KXTSBlockCipher, NISTCTSBlockCipher, OldCTSBlockCipher, PaddedBufferedBlockCipher
public class DefaultBufferedBlockCipher extends Object implements BufferedBlockCipher
A wrapper class that allows 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. Use this class for construction rather than BufferedBlockCipher as BufferedBlockCipher will eventually turn into an interface.

  • Field Details

    • buf

      protected byte[] buf

    • bufOff

      protected int bufOff

    • forEncryption

      protected boolean forEncryption

    • cipher

      protected BlockCipher cipher

    • mbCipher

      protected MultiBlockCipher mbCipher

    • partialBlockOkay

      protected boolean partialBlockOkay

    • pgpCFB

      protected boolean pgpCFB

  • Constructor Details

    • DefaultBufferedBlockCipher

      protected DefaultBufferedBlockCipher()
      constructor for subclasses

    • DefaultBufferedBlockCipher

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

  • Method Details

    • getUnderlyingCipher

      public BlockCipher getUnderlyingCipher()
      return the cipher this object wraps.
      Specified by:
      getUnderlyingCipher in interface BufferedBlockCipher
      Returns:
      the cipher this object wraps.

    • init

      public void init(boolean forEncryption, CipherParameters params) throws 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:
      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.

    • processByte

      public int processByte(byte in, byte[] out, int outOff) throws DataLengthException, IllegalStateException
      process a single byte, producing an output block if necessary.
      Specified by:
      processByte in interface BufferedBlockCipher
      Parameters:
      in - the input byte.
      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.
      IllegalStateException - if the cipher isn't initialised.

    • processBytes

      public int processBytes(byte[] in, int inOff, int len, byte[] out, int outOff) throws DataLengthException, 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.
      IllegalStateException - if the cipher isn't initialised.

    • doFinal

      public int doFinal(byte[] out, int outOff) throws DataLengthException, 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.
      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 String toString()
      Overrides:
      toString in class Object