Package org.bouncycastle.crypto.paddings

Interface BlockCipherPadding

All Known Implementing Classes:
ISO10126d2Padding, ISO7816d4Padding, PKCS7Padding, TBCPadding, X923Padding, ZeroBytePadding
public interface BlockCipherPadding
Block cipher padders are expected to conform to this interface

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    addPadding(byte[] in, int inOff)
    add the pad bytes to the passed in block, returning the number of bytes added.
    String
    getPaddingName()
    Return the name of the algorithm the cipher implements.
    void
    init(SecureRandom random)
    Initialise the padder.
    int
    padCount(byte[] in)
    return the number of pad bytes present in the block.

  • Method Details

    • init

      void init(SecureRandom random) throws IllegalArgumentException
      Initialise the padder.
      Parameters:
      random - the source of randomness for the padding, if required.
      Throws:
      IllegalArgumentException

    • getPaddingName

      String getPaddingName()
      Return the name of the algorithm the cipher implements.
      Returns:
      the name of the algorithm the cipher implements.

    • addPadding

      int addPadding(byte[] in, int inOff)
      add the pad bytes to the passed in block, returning the number of bytes added.

      Note: this assumes that the last block of plain text is always passed to it inside in. i.e. if inOff is zero, indicating the entire block is to be overwritten with padding the value of in should be the same as the last block of plain text. The reason for this is that some modes such as "trailing bit compliment" base the padding on the last byte of plain text.

    • padCount

      int padCount(byte[] in) throws InvalidCipherTextException
      return the number of pad bytes present in the block.
      Throws:
      InvalidCipherTextException - if the padding is badly formed or invalid.