Class BCrypt


  • public class BCrypt
    extends java.lang.Object
    BCrypt implements OpenBSD-style Blowfish password hashing using the scheme described in "A Future-Adaptable Password Scheme" by Niels Provos and David Mazieres.

    This password hashing system tries to thwart off-line password cracking using a computationally-intensive hashing algorithm, based on Bruce Schneier's Blowfish cipher. The work factor of the algorithm is parameterised, so it can be increased as computers get faster. The amount of work increases exponentially (2**log_rounds), so each increment is twice as much work. The default log_rounds is 10, and the valid range is 4 to 30.

    Version:
    0.2
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static int BLOWFISH_NUM_ROUNDS  
      private static int[] openbsd_iv  
      private int[] P  
      private static int[] P_orig  
      private int[] S  
      private static int[] S_orig  
    • Constructor Summary

      Constructors 
      Constructor Description
      BCrypt()  
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private void ekskey​(byte[] data, byte[] key)
      Perform the "enhanced key schedule" step described by Provos and Mazieres in "A Future-Adaptable Password Scheme" http://www.openbsd.org/papers/bcrypt-paper.ps
      private void encipher​(int[] lr, int off)
      Blowfish encipher a single 64-bit block encoded as two 32-bit halves
      void hash​(byte[] hpass, byte[] hsalt, byte[] output)
      Compatibility with new OpenBSD function.
      private void init_key()
      Initialise the Blowfish key schedule
      private void key​(byte[] key)
      Key the Blowfish cipher
      void pbkdf​(byte[] password, byte[] salt, int rounds, byte[] output)
      Compatibility with new OpenBSD function.
      private static int streamtoword​(byte[] data, int[] offp)
      Cycically extract a word of key material
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • P_orig

        private static final int[] P_orig
      • S_orig

        private static final int[] S_orig
      • openbsd_iv

        private static final int[] openbsd_iv
      • P

        private int[] P
      • S

        private int[] S
    • Constructor Detail

      • BCrypt

        public BCrypt()
    • Method Detail

      • encipher

        private void encipher​(int[] lr,
                              int off)
        Blowfish encipher a single 64-bit block encoded as two 32-bit halves
        Parameters:
        lr - an array containing the two 32-bit half blocks
        off - the position in the array of the blocks
      • streamtoword

        private static int streamtoword​(byte[] data,
                                        int[] offp)
        Cycically extract a word of key material
        Parameters:
        data - the string to extract the data from
        offp - a "pointer" (as a one-entry array) to the current offset into data
        Returns:
        the next word of material from data
      • init_key

        private void init_key()
        Initialise the Blowfish key schedule
      • key

        private void key​(byte[] key)
        Key the Blowfish cipher
        Parameters:
        key - an array containing the key
      • ekskey

        private void ekskey​(byte[] data,
                            byte[] key)
        Perform the "enhanced key schedule" step described by Provos and Mazieres in "A Future-Adaptable Password Scheme" http://www.openbsd.org/papers/bcrypt-paper.ps
        Parameters:
        data - salt information
        key - password information
      • hash

        public void hash​(byte[] hpass,
                         byte[] hsalt,
                         byte[] output)
        Compatibility with new OpenBSD function.
      • pbkdf

        public void pbkdf​(byte[] password,
                          byte[] salt,
                          int rounds,
                          byte[] output)
        Compatibility with new OpenBSD function.