Package org.bouncycastle.crypto.engines

Class Salsa20Engine

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int DEFAULT_ROUNDS  
      protected int[] engineState  
      protected int rounds  
      protected static byte[] sigma
      Deprecated. 
      protected static byte[] tau
      Deprecated. 
      protected int[] x  

    • Constructor Summary

      Constructors 
      Constructor Description
      Salsa20Engine()
      Creates a 20 round Salsa20 engine.
      Salsa20Engine​(int rounds)
      Creates a Salsa20 engine with a specific number of rounds.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected void advanceCounter()  
      protected void advanceCounter​(long diff)  
      protected void generateKeyStream​(byte[] output)  
      java.lang.String getAlgorithmName()
      Return the name of the algorithm the cipher implements.
      protected long getCounter()  
      protected int getNonceSize()  
      long getPosition()
      Return the current "position" of the cipher
      void init​(boolean forEncryption, CipherParameters params)
      initialise a Salsa20 cipher.
      protected void packTauOrSigma​(int keyLength, int[] state, int stateOffset)  
      int processBytes​(byte[] in, int inOff, int len, byte[] out, int outOff)
      process a block of bytes from in putting the result into out.
      void reset()
      reset the cipher.
      protected void resetCounter()  
      protected void retreatCounter()  
      protected void retreatCounter​(long diff)  
      byte returnByte​(byte in)
      encrypt/decrypt a single byte returning the result.
      static void salsaCore​(int rounds, int[] input, int[] x)
      Salsa20 function
      long seekTo​(long position)
      Reset the cipher and then skip forward to a given position.
      protected void setKey​(byte[] keyBytes, byte[] ivBytes)  
      long skip​(long numberOfBytes)
      Skip numberOfBytes forwards, or backwards.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • sigma

        protected static final byte[] sigma
        Deprecated.

      • tau

        protected static final byte[] tau
        Deprecated.

      • rounds

        protected int rounds

      • engineState

        protected int[] engineState

      • x

        protected int[] x

    • Constructor Detail

      • Salsa20Engine

        public Salsa20Engine()
        Creates a 20 round Salsa20 engine.

      • Salsa20Engine

        public Salsa20Engine​(int rounds)
        Creates a Salsa20 engine with a specific number of rounds.
        Parameters:
        rounds - the number of rounds (must be an even number).

    • Method Detail

      • packTauOrSigma

        protected void packTauOrSigma​(int keyLength,
                              int[] state,
                              int stateOffset)

      • init

        public void init​(boolean forEncryption,
                 CipherParameters params)
        initialise a Salsa20 cipher.
        Specified by:
        init in interface StreamCipher
        Parameters:
        forEncryption - whether or not we are for encryption.
        params - the parameters required to set up the cipher.
        Throws:
        java.lang.IllegalArgumentException - if the params argument is inappropriate.

      • getNonceSize

        protected int getNonceSize()

      • getAlgorithmName

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

      • returnByte

        public byte returnByte​(byte in)
        Description copied from interface: StreamCipher
        encrypt/decrypt a single byte returning the result.
        Specified by:
        returnByte in interface StreamCipher
        Parameters:
        in - the byte to be processed.
        Returns:
        the result of processing the input byte.

      • advanceCounter

        protected void advanceCounter​(long diff)

      • advanceCounter

        protected void advanceCounter()

      • retreatCounter

        protected void retreatCounter​(long diff)

      • retreatCounter

        protected void retreatCounter()

      • processBytes

        public int processBytes​(byte[] in,
                        int inOff,
                        int len,
                        byte[] out,
                        int outOff)
        Description copied from interface: StreamCipher
        process a block of bytes from in putting the result into out.
        Specified by:
        processBytes in interface StreamCipher
        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.

      • 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.

      • reset

        public void reset()
        Description copied from interface: StreamCipher
        reset the cipher. This leaves it in the same state it was at after the last init (if there was one).
        Specified by:
        reset in interface StreamCipher

      • getCounter

        protected long getCounter()

      • resetCounter

        protected void resetCounter()

      • setKey

        protected void setKey​(byte[] keyBytes,
                      byte[] ivBytes)

      • generateKeyStream

        protected void generateKeyStream​(byte[] output)

      • salsaCore

        public static void salsaCore​(int rounds,
                             int[] input,
                             int[] x)
        Salsa20 function
        Parameters:
        input - input data