Package org.bouncycastle.crypto.modes

Class SICBlockCipher

  • All Implemented Interfaces:
    BlockCipher, CTRModeCipher, MultiBlockCipher, SkippingCipher, SkippingStreamCipher, StreamCipher
    public class SICBlockCipher
extends StreamBlockCipher
implements CTRModeCipher
    Implements the Segmented Integer Counter (SIC) mode on top of a simple block cipher. This mode is also known as CTR mode.

    With an IV shorter than the block size, the counter occupies the remaining low bytes and running past its range throws an IllegalStateException. With a full-block IV the whole block is the counter; the advance since init is bounded at 2^64 blocks (the widest range getPosition()/skip arithmetic can represent), past which the same exception is thrown.

    • Constructor Detail

      • SICBlockCipher

        @Deprecated
public SICBlockCipher​(BlockCipher c)
        Deprecated.
        use newInstance() method.
        Basic constructor.
        Parameters:
        c - the block cipher to be used.

    • Method Detail

      • newInstance

        public static CTRModeCipher newInstance​(BlockCipher cipher)
        Return a new SIC/CTR mode cipher based on the passed in base cipher
        Parameters:
        cipher - the base cipher for the SIC/CTR mode.

      • init

        public void init​(boolean forEncryption,
                 CipherParameters params)
          throws java.lang.IllegalArgumentException
        Description copied from interface: BlockCipher
        Initialise the cipher.
        Specified by:
        init in interface BlockCipher
        Specified by:
        init in interface StreamCipher
        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.

      • getAlgorithmName

        public java.lang.String getAlgorithmName()
        Description copied from interface: BlockCipher
        Return the name of the algorithm the cipher implements.
        Specified by:
        getAlgorithmName in interface BlockCipher
        Specified by:
        getAlgorithmName in interface StreamCipher
        Returns:
        the name of the algorithm the cipher implements.

      • getBlockSize

        public int getBlockSize()
        Description copied from interface: BlockCipher
        Return the block size for this cipher (in bytes).
        Specified by:
        getBlockSize in interface BlockCipher
        Returns:
        the block size for this cipher in bytes.

      • processBlock

        public int processBlock​(byte[] in,
                        int inOff,
                        byte[] out,
                        int outOff)
                 throws DataLengthException,
                        java.lang.IllegalStateException
        Description copied from interface: BlockCipher
        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 input , or space in out.
        java.lang.IllegalStateException - if the cipher isn't initialised.

      • processBytes

        public int processBytes​(byte[] in,
                        int inOff,
                        int len,
                        byte[] out,
                        int outOff)
                 throws DataLengthException
        Description copied from interface: StreamCipher
        process a block of bytes from in putting the result into out.
        Specified by:
        processBytes in interface StreamCipher
        Overrides:
        processBytes in class StreamBlockCipher
        Parameters:
        in - the input byte array.
        inOff - the offset into the in array where the data to be processed starts.
        len - the number of bytes to be processed.
        out - the output buffer the processed bytes go into.
        outOff - the offset into the output byte array the processed data starts at.
        Returns:
        the number of bytes produced - should always be len.
        Throws:
        DataLengthException - if the output buffer is too small.

      • reset

        public void reset()
        Description copied from interface: BlockCipher
        Reset the cipher. After resetting the cipher is in the same state as it was after the last init (if there was one).
        Specified by:
        reset in interface BlockCipher
        Specified by:
        reset in interface StreamCipher

      • skip

        public long skip​(long numberOfBytes)
        Description copied from interface: SkippingCipher
        Skip numberOfBytes forwards, or backwards.
        Specified by:
        skip in interface SkippingCipher
        Parameters:
        numberOfBytes - the number of bytes to skip (positive forward, negative backwards).
        Returns:
        the number of bytes actually skipped.

      • seekTo

        public long seekTo​(long position)
        Description copied from interface: SkippingCipher
        Reset the cipher and then skip forward to a given position.
        Specified by:
        seekTo in interface SkippingCipher
        Parameters:
        position - the number of bytes in to set the cipher state to.
        Returns:
        the byte position moved to.

      • getPosition

        public long getPosition()
        Description copied from interface: SkippingCipher
        Return the current "position" of the cipher
        Specified by:
        getPosition in interface SkippingCipher
        Returns:
        the current byte position.