content: package com.amdelamar.jhash.algorithms;
  
  import com.amdelamar.jhash.util.HashUtils;
  
  import java.io.UnsupportedEncodingException;
  
  /**
   * BCrypt implements OpenBSD-style Blowfish password hashing using the scheme described in "A
   * Future-Adaptable Password Scheme" by Niels Provos and David Mazieres.
   *
   * @author amdelamar, djm
   * @see <a href="https://en.wikipedia.org/wiki/Bcrypt">https://en.wikipedia.org/wiki/Bcrypt</a>
   */
  public class BCrypt {
  
      public static final int DEFAULT_SALT_LENGTH = 16;
      public static final int DEFAULT_LOG2_ROUNDS = 13;
      public static final int BLOWFISH_ROUNDS = 16;
  
      // Initial contents of key schedule
      private static final int[] P_ARRAY = {0x243f6a88, 0x85a308d3, 0x13198a2e, 0x03707344, 0xa4093822, 0x299f31d0, 0x082efa98, 0xec4e6c89,
              0x452821e6, 0x38d01377, 0xbe5466cf, 0x34e90c6c, 0xc0ac29b7, 0xc97c50dd, 0x3f84d5b5, 0xb5470917, 0x9216d5d9, 0x8979fb1b};
  
      private static final int[] S_BOX = {0xd1310ba6, 0x98dfb5ac, 0x2ffd72db, 0xd01adfb7, 0xb8e1afed, 0x6a267e96, 0xba7c9045, 0xf12c7f99,
              0x24a19947, 0xb3916cf7, 0x0801f2e2, 0x858efc16, 0x636920d8, 0x71574e69, 0xa458fea3, 0xf4933d7e, 0x0d95748f, 0x728eb658,
              0x718bcd58, 0x82154aee, 0x7b54a41d, 0xc25a59b5, 0x9c30d539, 0x2af26013, 0xc5d1b023, 0x286085f0, 0xca417918, 0xb8db38ef,
              0x8e79dcb0, 0x603a180e, 0x6c9e0e8b, 0xb01e8a3e, 0xd71577c1, 0xbd314b27, 0x78af2fda, 0x55605c60, 0xe65525f3, 0xaa55ab94,
              0x57489862, 0x63e81440, 0x55ca396a, 0x2aab10b6, 0xb4cc5c34, 0x1141e8ce, 0xa15486af, 0x7c72e993, 0xb3ee1411, 0x636fbc2a,
              0x2ba9c55d, 0x741831f6, 0xce5c3e16, 0x9b87931e, 0xafd6ba33, 0x6c24cf5c, 0x7a325381, 0x28958677, 0x3b8f4898, 0x6b4bb9af,
              0xc4bfe81b, 0x66282193, 0x61d809cc, 0xfb21a991, 0x487cac60, 0x5dec8032, 0xef845d5d, 0xe98575b1, 0xdc262302, 0xeb651b88,
              0x23893e81, 0xd396acc5, 0x0f6d6ff3, 0x83f44239, 0x2e0b4482, 0xa4842004, 0x69c8f04a, 0x9e1f9b5e, 0x21c66842, 0xf6e96c9a,
              0x670c9c61, 0xabd388f0, 0x6a51a0d2, 0xd8542f68, 0x960fa728, 0xab5133a3, 0x6eef0b6c, 0x137a3be4, 0xba3bf050, 0x7efb2a98,
              0xa1f1651d, 0x39af0176, 0x66ca593e, 0x82430e88, 0x8cee8619, 0x456f9fb4, 0x7d84a5c3, 0x3b8b5ebe, 0xe06f75d8, 0x85c12073,
              0x401a449f, 0x56c16aa6, 0x4ed3aa62, 0x363f7706, 0x1bfedf72, 0x429b023d, 0x37d0d724, 0xd00a1248, 0xdb0fead3, 0x49f1c09b,
              0x075372c9, 0x80991b7b, 0x25d479d8, 0xf6e8def7, 0xe3fe501a, 0xb6794c3b, 0x976ce0bd, 0x04c006ba, 0xc1a94fb6, 0x409f60c4,
              0x5e5c9ec2, 0x196a2463, 0x68fb6faf, 0x3e6c53b5, 0x1339b2eb, 0x3b52ec6f, 0x6dfc511f, 0x9b30952c, 0xcc814544, 0xaf5ebd09,
              0xbee3d004, 0xde334afd, 0x660f2807, 0x192e4bb3, 0xc0cba857, 0x45c8740f, 0xd20b5f39, 0xb9d3fbdb, 0x5579c0bd, 0x1a60320a,
              0xd6a100c6, 0x402c7279, 0x679f25fe, 0xfb1fa3cc, 0x8ea5e9f8, 0xdb3222f8, 0x3c7516df, 0xfd616b15, 0x2f501ec8, 0xad0552ab,
              0x323db5fa, 0xfd238760, 0x53317b48, 0x3e00df82, 0x9e5c57bb, 0xca6f8ca0, 0x1a87562e, 0xdf1769db, 0xd542a8f6, 0x287effc3,
              0xac6732c6, 0x8c4f5573, 0x695b27b0, 0xbbca58c8, 0xe1ffa35d, 0xb8f011a0, 0x10fa3d98, 0xfd2183b8, 0x4afcb56c, 0x2dd1d35b,
              0x9a53e479, 0xb6f84565, 0xd28e49bc, 0x4bfb9790, 0xe1ddf2da, 0xa4cb7e33, 0x62fb1341, 0xcee4c6e8, 0xef20cada, 0x36774c01,
              0xd07e9efe, 0x2bf11fb4, 0x95dbda4d, 0xae909198, 0xeaad8e71, 0x6b93d5a0, 0xd08ed1d0, 0xafc725e0, 0x8e3c5b2f, 0x8e7594b7,
              0x8ff6e2fb, 0xf2122b64, 0x8888b812, 0x900df01c, 0x4fad5ea0, 0x688fc31c, 0xd1cff191, 0xb3a8c1ad, 0x2f2f2218, 0xbe0e1777,
              0xea752dfe, 0x8b021fa1, 0xe5a0cc0f, 0xb56f74e8, 0x18acf3d6, 0xce89e299, 0xb4a84fe0, 0xfd13e0b7, 0x7cc43b81, 0xd2ada8d9,
              0x165fa266, 0x80957705, 0x93cc7314, 0x211a1477, 0xe6ad2065, 0x77b5fa86, 0xc75442f5, 0xfb9d35cf, 0xebcdaf0c, 0x7b3e89a0,
              0xd6411bd3, 0xae1e7e49, 0x00250e2d, 0x2071b35e, 0x226800bb, 0x57b8e0af, 0x2464369b, 0xf009b91e, 0x5563911d, 0x59dfa6aa,
              0x78c14389, 0xd95a537f, 0x207d5ba2, 0x02e5b9c5, 0x83260376, 0x6295cfa9, 0x11c81968, 0x4e734a41, 0xb3472dca, 0x7b14a94a,
              0x1b510052, 0x9a532915, 0xd60f573f, 0xbc9bc6e4, 0x2b60a476, 0x81e67400, 0x08ba6fb5, 0x571be91f, 0xf296ec6b, 0x2a0dd915,
              0xb6636521, 0xe7b9f9b6, 0xff34052e, 0xc5855664, 0x53b02d5d, 0xa99f8fa1, 0x08ba4799, 0x6e85076a, 0x4b7a70e9, 0xb5b32944,
              0xdb75092e, 0xc4192623, 0xad6ea6b0, 0x49a7df7d, 0x9cee60b8, 0x8fedb266, 0xecaa8c71, 0x699a17ff, 0x5664526c, 0xc2b19ee1,
              0x193602a5, 0x75094c29, 0xa0591340, 0xe4183a3e, 0x3f54989a, 0x5b429d65, 0x6b8fe4d6, 0x99f73fd6, 0xa1d29c07, 0xefe830f5,
              0x4d2d38e6, 0xf0255dc1, 0x4cdd2086, 0x8470eb26, 0x6382e9c6, 0x021ecc5e, 0x09686b3f, 0x3ebaefc9, 0x3c971814, 0x6b6a70a1,
              0x687f3584, 0x52a0e286, 0xb79c5305, 0xaa500737, 0x3e07841c, 0x7fdeae5c, 0x8e7d44ec, 0x5716f2b8, 0xb03ada37, 0xf0500c0d,
              0xf01c1f04, 0x0200b3ff, 0xae0cf51a, 0x3cb574b2, 0x25837a58, 0xdc0921bd, 0xd19113f9, 0x7ca92ff6, 0x94324773, 0x22f54701,
              0x3ae5e581, 0x37c2dadc, 0xc8b57634, 0x9af3dda7, 0xa9446146, 0x0fd0030e, 0xecc8c73e, 0xa4751e41, 0xe238cd99, 0x3bea0e2f,
              0x3280bba1, 0x183eb331, 0x4e548b38, 0x4f6db908, 0x6f420d03, 0xf60a04bf, 0x2cb81290, 0x24977c79, 0x5679b072, 0xbcaf89af,
              0xde9a771f, 0xd9930810, 0xb38bae12, 0xdccf3f2e, 0x5512721f, 0x2e6b7124, 0x501adde6, 0x9f84cd87, 0x7a584718, 0x7408da17,
              0xbc9f9abc, 0xe94b7d8c, 0xec7aec3a, 0xdb851dfa, 0x63094366, 0xc464c3d2, 0xef1c1847, 0x3215d908, 0xdd433b37, 0x24c2ba16,
              0x12a14d43, 0x2a65c451, 0x50940002, 0x133ae4dd, 0x71dff89e, 0x10314e55, 0x81ac77d6, 0x5f11199b, 0x043556f1, 0xd7a3c76b,
              0x3c11183b, 0x5924a509, 0xf28fe6ed, 0x97f1fbfa, 0x9ebabf2c, 0x1e153c6e, 0x86e34570, 0xeae96fb1, 0x860e5e0a, 0x5a3e2ab3,
              0x771fe71c, 0x4e3d06fa, 0x2965dcb9, 0x99e71d0f, 0x803e89d6, 0x5266c825, 0x2e4cc978, 0x9c10b36a, 0xc6150eba, 0x94e2ea78,
              0xa5fc3c53, 0x1e0a2df4, 0xf2f74ea7, 0x361d2b3d, 0x1939260f, 0x19c27960, 0x5223a708, 0xf71312b6, 0xebadfe6e, 0xeac31f66,
              0xe3bc4595, 0xa67bc883, 0xb17f37d1, 0x018cff28, 0xc332ddef, 0xbe6c5aa5, 0x65582185, 0x68ab9802, 0xeecea50f, 0xdb2f953b,
              0x2aef7dad, 0x5b6e2f84, 0x1521b628, 0x29076170, 0xecdd4775, 0x619f1510, 0x13cca830, 0xeb61bd96, 0x0334fe1e, 0xaa0363cf,
              0xb5735c90, 0x4c70a239, 0xd59e9e0b, 0xcbaade14, 0xeecc86bc, 0x60622ca7, 0x9cab5cab, 0xb2f3846e, 0x648b1eaf, 0x19bdf0ca,
              0xa02369b9, 0x655abb50, 0x40685a32, 0x3c2ab4b3, 0x319ee9d5, 0xc021b8f7, 0x9b540b19, 0x875fa099, 0x95f7997e, 0x623d7da8,
              0xf837889a, 0x97e32d77, 0x11ed935f, 0x16681281, 0x0e358829, 0xc7e61fd6, 0x96dedfa1, 0x7858ba99, 0x57f584a5, 0x1b227263,
              0x9b83c3ff, 0x1ac24696, 0xcdb30aeb, 0x532e3054, 0x8fd948e4, 0x6dbc3128, 0x58ebf2ef, 0x34c6ffea, 0xfe28ed61, 0xee7c3c73,
              0x5d4a14d9, 0xe864b7e3, 0x42105d14, 0x203e13e0, 0x45eee2b6, 0xa3aaabea, 0xdb6c4f15, 0xfacb4fd0, 0xc742f442, 0xef6abbb5,
              0x654f3b1d, 0x41cd2105, 0xd81e799e, 0x86854dc7, 0xe44b476a, 0x3d816250, 0xcf62a1f2, 0x5b8d2646, 0xfc8883a0, 0xc1c7b6a3,
              0x7f1524c3, 0x69cb7492, 0x47848a0b, 0x5692b285, 0x095bbf00, 0xad19489d, 0x1462b174, 0x23820e00, 0x58428d2a, 0x0c55f5ea,
              0x1dadf43e, 0x233f7061, 0x3372f092, 0x8d937e41, 0xd65fecf1, 0x6c223bdb, 0x7cde3759, 0xcbee7460, 0x4085f2a7, 0xce77326e,
              0xa6078084, 0x19f8509e, 0xe8efd855, 0x61d99735, 0xa969a7aa, 0xc50c06c2, 0x5a04abfc, 0x800bcadc, 0x9e447a2e, 0xc3453484,
              0xfdd56705, 0x0e1e9ec9, 0xdb73dbd3, 0x105588cd, 0x675fda79, 0xe3674340, 0xc5c43465, 0x713e38d8, 0x3d28f89e, 0xf16dff20,
              0x153e21e7, 0x8fb03d4a, 0xe6e39f2b, 0xdb83adf7, 0xe93d5a68, 0x948140f7, 0xf64c261c, 0x94692934, 0x411520f7, 0x7602d4f7,
              0xbcf46b2e, 0xd4a20068, 0xd4082471, 0x3320f46a, 0x43b7d4b7, 0x500061af, 0x1e39f62e, 0x97244546, 0x14214f74, 0xbf8b8840,
              0x4d95fc1d, 0x96b591af, 0x70f4ddd3, 0x66a02f45, 0xbfbc09ec, 0x03bd9785, 0x7fac6dd0, 0x31cb8504, 0x96eb27b3, 0x55fd3941,
              0xda2547e6, 0xabca0a9a, 0x28507825, 0x530429f4, 0x0a2c86da, 0xe9b66dfb, 0x68dc1462, 0xd7486900, 0x680ec0a4, 0x27a18dee,
              0x4f3ffea2, 0xe887ad8c, 0xb58ce006, 0x7af4d6b6, 0xaace1e7c, 0xd3375fec, 0xce78a399, 0x406b2a42, 0x20fe9e35, 0xd9f385b9,
              0xee39d7ab, 0x3b124e8b, 0x1dc9faf7, 0x4b6d1856, 0x26a36631, 0xeae397b2, 0x3a6efa74, 0xdd5b4332, 0x6841e7f7, 0xca7820fb,
              0xfb0af54e, 0xd8feb397, 0x454056ac, 0xba489527, 0x55533a3a, 0x20838d87, 0xfe6ba9b7, 0xd096954b, 0x55a867bc, 0xa1159a58,
              0xcca92963, 0x99e1db33, 0xa62a4a56, 0x3f3125f9, 0x5ef47e1c, 0x9029317c, 0xfdf8e802, 0x04272f70, 0x80bb155c, 0x05282ce3,
              0x95c11548, 0xe4c66d22, 0x48c1133f, 0xc70f86dc, 0x07f9c9ee, 0x41041f0f, 0x404779a4, 0x5d886e17, 0x325f51eb, 0xd59bc0d1,
              0xf2bcc18f, 0x41113564, 0x257b7834, 0x602a9c60, 0xdff8e8a3, 0x1f636c1b, 0x0e12b4c2, 0x02e1329e, 0xaf664fd1, 0xcad18115,
              0x6b2395e0, 0x333e92e1, 0x3b240b62, 0xeebeb922, 0x85b2a20e, 0xe6ba0d99, 0xde720c8c, 0x2da2f728, 0xd0127845, 0x95b794fd,
              0x647d0862, 0xe7ccf5f0, 0x5449a36f, 0x877d48fa, 0xc39dfd27, 0xf33e8d1e, 0x0a476341, 0x992eff74, 0x3a6f6eab, 0xf4f8fd37,
              0xa812dc60, 0xa1ebddf8, 0x991be14c, 0xdb6e6b0d, 0xc67b5510, 0x6d672c37, 0x2765d43b, 0xdcd0e804, 0xf1290dc7, 0xcc00ffa3,
              0xb5390f92, 0x690fed0b, 0x667b9ffb, 0xcedb7d9c, 0xa091cf0b, 0xd9155ea3, 0xbb132f88, 0x515bad24, 0x7b9479bf, 0x763bd6eb,
              0x37392eb3, 0xcc115979, 0x8026e297, 0xf42e312d, 0x6842ada7, 0xc66a2b3b, 0x12754ccc, 0x782ef11c, 0x6a124237, 0xb79251e7,
              0x06a1bbe6, 0x4bfb6350, 0x1a6b1018, 0x11caedfa, 0x3d25bdd8, 0xe2e1c3c9, 0x44421659, 0x0a121386, 0xd90cec6e, 0xd5abea2a,
              0x64af674e, 0xda86a85f, 0xbebfe988, 0x64e4c3fe, 0x9dbc8057, 0xf0f7c086, 0x60787bf8, 0x6003604d, 0xd1fd8346, 0xf6381fb0,
              0x7745ae04, 0xd736fccc, 0x83426b33, 0xf01eab71, 0xb0804187, 0x3c005e5f, 0x77a057be, 0xbde8ae24, 0x55464299, 0xbf582e61,
              0x4e58f48f, 0xf2ddfda2, 0xf474ef38, 0x8789bdc2, 0x5366f9c3, 0xc8b38e74, 0xb475f255, 0x46fcd9b9, 0x7aeb2661, 0x8b1ddf84,
              0x846a0e79, 0x915f95e2, 0x466e598e, 0x20b45770, 0x8cd55591, 0xc902de4c, 0xb90bace1, 0xbb8205d0, 0x11a86248, 0x7574a99e,
              0xb77f19b6, 0xe0a9dc09, 0x662d09a1, 0xc4324633, 0xe85a1f02, 0x09f0be8c, 0x4a99a025, 0x1d6efe10, 0x1ab93d1d, 0x0ba5a4df,
              0xa186f20f, 0x2868f169, 0xdcb7da83, 0x573906fe, 0xa1e2ce9b, 0x4fcd7f52, 0x50115e01, 0xa70683fa, 0xa002b5c4, 0x0de6d027,
              0x9af88c27, 0x773f8641, 0xc3604c06, 0x61a806b5, 0xf0177a28, 0xc0f586e0, 0x006058aa, 0x30dc7d62, 0x11e69ed7, 0x2338ea63,
              0x53c2dd94, 0xc2c21634, 0xbbcbee56, 0x90bcb6de, 0xebfc7da1, 0xce591d76, 0x6f05e409, 0x4b7c0188, 0x39720a3d, 0x7c927c24,
              0x86e3725f, 0x724d9db9, 0x1ac15bb4, 0xd39eb8fc, 0xed545578, 0x08fca5b5, 0xd83d7cd3, 0x4dad0fc4, 0x1e50ef5e, 0xb161e6f8,
              0xa28514d9, 0x6c51133c, 0x6fd5c7e7, 0x56e14ec4, 0x362abfce, 0xddc6c837, 0xd79a3234, 0x92638212, 0x670efa8e, 0x406000e0,
              0x3a39ce37, 0xd3faf5cf, 0xabc27737, 0x5ac52d1b, 0x5cb0679e, 0x4fa33742, 0xd3822740, 0x99bc9bbe, 0xd5118e9d, 0xbf0f7315,
              0xd62d1c7e, 0xc700c47b, 0xb78c1b6b, 0x21a19045, 0xb26eb1be, 0x6a366eb4, 0x5748ab2f, 0xbc946e79, 0xc6a376d2, 0x6549c2c8,
              0x530ff8ee, 0x468dde7d, 0xd5730a1d, 0x4cd04dc6, 0x2939bbdb, 0xa9ba4650, 0xac9526e8, 0xbe5ee304, 0xa1fad5f0, 0x6a2d519a,
              0x63ef8ce2, 0x9a86ee22, 0xc089c2b8, 0x43242ef6, 0xa51e03aa, 0x9cf2d0a4, 0x83c061ba, 0x9be96a4d, 0x8fe51550, 0xba645bd6,
              0x2826a2f9, 0xa73a3ae1, 0x4ba99586, 0xef5562e9, 0xc72fefd3, 0xf752f7da, 0x3f046f69, 0x77fa0a59, 0x80e4a915, 0x87b08601,
              0x9b09e6ad, 0x3b3ee593, 0xe990fd5a, 0x9e34d797, 0x2cf0b7d9, 0x022b8b51, 0x96d5ac3a, 0x017da67d, 0xd1cf3ed6, 0x7c7d2d28,
              0x1f9f25cf, 0xadf2b89b, 0x5ad6b472, 0x5a88f54c, 0xe029ac71, 0xe019a5e6, 0x47b0acfd, 0xed93fa9b, 0xe8d3c48d, 0x283b57cc,
              0xf8d56629, 0x79132e28, 0x785f0191, 0xed756055, 0xf7960e44, 0xe3d35e8c, 0x15056dd4, 0x88f46dba, 0x03a16125, 0x0564f0bd,
              0xc3eb9e15, 0x3c9057a2, 0x97271aec, 0xa93a072a, 0x1b3f6d9b, 0x1e6321f5, 0xf59c66fb, 0x26dcf319, 0x7533d928, 0xb155fdf5,
              0x03563482, 0x8aba3cbb, 0x28517711, 0xc20ad9f8, 0xabcc5167, 0xccad925f, 0x4de81751, 0x3830dc8e, 0x379d5862, 0x9320f991,
              0xea7a90c2, 0xfb3e7bce, 0x5121ce64, 0x774fbe32, 0xa8b6e37e, 0xc3293d46, 0x48de5369, 0x6413e680, 0xa2ae0810, 0xdd6db224,
              0x69852dfd, 0x09072166, 0xb39a460a, 0x6445c0dd, 0x586cdecf, 0x1c20c8ae, 0x5bbef7dd, 0x1b588d40, 0xccd2017f, 0x6bb4e3bb,
              0xdda26a7e, 0x3a59ff45, 0x3e350a44, 0xbcb4cdd5, 0x72eacea8, 0xfa6484bb, 0x8d6612ae, 0xbf3c6f47, 0xd29be463, 0x542f5d9e,
              0xaec2771b, 0xf64e6370, 0x740e0d8d, 0xe75b1357, 0xf8721671, 0xaf537d5d, 0x4040cb08, 0x4eb4e2cc, 0x34d2466a, 0x0115af84,
              0xe1b00428, 0x95983a1d, 0x06b89fb4, 0xce6ea048, 0x6f3f3b82, 0x3520ab82, 0x011a1d4b, 0x277227f8, 0x611560b1, 0xe7933fdc,
              0xbb3a792b, 0x344525bd, 0xa08839e1, 0x51ce794b, 0x2f32c9b7, 0xa01fbac9, 0xe01cc87e, 0xbcc7d1f6, 0xcf0111c3, 0xa1e8aac7,
              0x1a908749, 0xd44fbd9a, 0xd0dadecb, 0xd50ada38, 0x0339c32a, 0xc6913667, 0x8df9317c, 0xe0b12b4f, 0xf79e59b7, 0x43f5bb3a,
              0xf2d519ff, 0x27d9459c, 0xbf97222c, 0x15e6fc2a, 0x0f91fc71, 0x9b941525, 0xfae59361, 0xceb69ceb, 0xc2a86459, 0x12baa8d1,
              0xb6c1075e, 0xe3056a0c, 0x10d25065, 0xcb03a442, 0xe0ec6e0e, 0x1698db3b, 0x4c98a0be, 0x3278e964, 0x9f1f9532, 0xe0d392df,
              0xd3a0342b, 0x8971f21e, 0x1b0a7441, 0x4ba3348c, 0xc5be7120, 0xc37632d8, 0xdf359f8d, 0x9b992f2e, 0xe60b6f47, 0x0fe3f11d,
              0xe54cda54, 0x1edad891, 0xce6279cf, 0xcd3e7e6f, 0x1618b166, 0xfd2c1d05, 0x848fd2c5, 0xf6fb2299, 0xf523f357, 0xa6327623,
              0x93a83531, 0x56cccd02, 0xacf08162, 0x5a75ebb5, 0x6e163697, 0x88d273cc, 0xde966292, 0x81b949d0, 0x4c50901b, 0x71c65614,
              0xe6c6c7bd, 0x327a140a, 0x45e1d006, 0xc3f27b9a, 0xc9aa53fd, 0x62a80f00, 0xbb25bfe2, 0x35bdd2f6, 0x71126905, 0xb2040222,
              0xb6cbcf7c, 0xcd769c2b, 0x53113ec0, 0x1640e3d3, 0x38abbd60, 0x2547adf0, 0xba38209c, 0xf746ce76, 0x77afa1c5, 0x20756060,
              0x85cbfe4e, 0x8ae88dd8, 0x7aaaf9b0, 0x4cf9aa7e, 0x1948c25c, 0x02fb8a8c, 0x01c36ae4, 0xd6ebe1f9, 0x90d4f869, 0xa65cdea0,
              0x3f09252d, 0xc208e69f, 0xb74e6132, 0xce77e25b, 0x578fdfe3, 0x3ac372e6};
  
      private static final int[] CIPHER = {0x4f727068, 0x65616e42, 0x65686f6c, 0x64657253, 0x63727944, 0x6f756274};
  
      // Table for Special Base64 encoding
      private static final char[] BASE64 = {'.', '/', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
              'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p',
              'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
  
      // Table for Special Base64 decoding
      private static final byte[] IBASE64 = {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
              -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 54, 55, 56, 57, 58, 59, 60, 61,
              62, 63, -1, -1, -1, -1, -1, -1, -1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
              27, -1, -1, -1, -1, -1, -1, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,
              53, -1, -1, -1, -1, -1};
  
      // Expanded Blowfish key
      private static int[] pA;
      private static int[] sB;
  
      /**
       * This returns a String using bcrypt's slightly-modified base64 encoding scheme. Note that this
       * is *not* compatible with the standard MIME-base64 encoding.
       *
       * @param array the byte array to encode
       * @param len   the number of bytes to encode
       * @return base64-encoded string
       * @throws IllegalArgumentException if the length is invalid
       */
      private static String encodeBase64(byte[] array, int len) throws IllegalArgumentException {
  
          if (len <= 0 || len > array.length) {
              throw new IllegalArgumentException("Invalid length");
          }
  
          StringBuilder rs = new StringBuilder();
          int c1;
          int c2;
          int off = 0;
          while (off < len) {
              c1 = array[off++] & 0xff;
              rs.append(BASE64[(c1 >> 2) & 0x3f]);
              c1 = (c1 & 0x03) << 4;
              if (off >= len) {
                  rs.append(BASE64[c1 & 0x3f]);
                  break;
              }
              c2 = array[off++] & 0xff;
              c1 |= (c2 >> 4) & 0x0f;
              rs.append(BASE64[c1 & 0x3f]);
              c1 = (c2 & 0x0f) << 2;
              if (off >= len) {
                  rs.append(BASE64[c1 & 0x3f]);
                  break;
              }
              c2 = array[off++] & 0xff;
              c1 |= (c2 >> 6) & 0x03;
              rs.append(BASE64[c1 & 0x3f]);
              rs.append(BASE64[c2 & 0x3f]);
          }
          return rs.toString();
      }
  
      /**
       * Look up the 3 bits base64-encoded by the specified character, range-checking against
       * conversion table
       *
       * @param character the base64-encoded value
       * @return the decoded value of x
       */
      private static byte char64(char character) {
          if ((int) character < 0 || (int) character >= IBASE64.length) {
              return -1;
          }
          return IBASE64[(int) character];
      }
  
      /**
       * This returns a string encoded using bcrypt's base64 scheme to a byte array. Note that this is
       * *not* compatible with the standard MIME-base64 encoding.
       *
       * @param string  the string to decode
       * @param maxolen the maximum number of bytes to decode
       * @return an array containing the decoded bytes
       * @throws IllegalArgumentException if maxolen is invalid
       */
      private static byte[] decodeBase64(String string, int maxolen) throws IllegalArgumentException {
  
          if (maxolen <= 0) {
              throw new IllegalArgumentException("Invalid maxolen");
          }
  
          StringBuilder sb = new StringBuilder();
          int off = 0;
          int slen = string.length();
          int olen = 0;
  
          while (off < slen - 1 && olen < maxolen) {
              byte c1 = char64(string.charAt(off++));
              byte c2 = char64(string.charAt(off++));
              if (c1 == -1 || c2 == -1) {
                  break;
              }
              byte o1 = (byte) (c1 << 2);
              o1 |= (c2 & 0x30) >> 4;
              sb.append((char) o1);
              if (++olen >= maxolen || off >= slen) {
                  break;
              }
              byte c3 = char64(string.charAt(off++));
              if (c3 == -1) {
                  break;
              }
              o1 = (byte) ((c2 & 0x0f) << 4);
              o1 |= (c3 & 0x3c) >> 2;
              sb.append((char) o1);
              if (++olen >= maxolen || off >= slen) {
                  break;
              }
              byte c4 = char64(string.charAt(off++));
              o1 = (byte) ((c3 & 0x03) << 6);
              o1 |= c4;
              sb.append((char) o1);
              ++olen;
          }
  
          byte[] ret = new byte[olen];
          for (off = 0; off < olen; off++) {
              ret[off] = (byte) sb.charAt(off);
          }
          return ret;
      }
  
      /**
       * Blowfish encipher a single 64-bit block encoded as two 32-bit halves
       *
       * @param block an array containing the two 32-bit half blocks
       * @param off   the position in the array of the blocks
       */
      private static final void encipher(int[] block, int off) {
          int n1;
          int left = block[off];
          int right = block[off + 1];
  
          left ^= pA[0];
          for (int i = 0; i <= BLOWFISH_ROUNDS - 2; ) {
              // Feistel substitution on left word
              n1 = sB[(left >> 24) & 0xff];
              n1 += sB[0x100 | ((left >> 16) & 0xff)];
              n1 ^= sB[0x200 | ((left >> 8) & 0xff)];
              n1 += sB[0x300 | (left & 0xff)];
              right ^= n1 ^ pA[++i];
  
              // Feistel substitution on right word
              n1 = sB[(right >> 24) & 0xff];
              n1 += sB[0x100 | ((right >> 16) & 0xff)];
              n1 ^= sB[0x200 | ((right >> 8) & 0xff)];
              n1 += sB[0x300 | (right & 0xff)];
              left ^= n1 ^ pA[++i];
          }
          block[off] = right ^ pA[BLOWFISH_ROUNDS + 1];
          block[off + 1] = left;
      }
  
      /**
       * Cyclically extract a word of key material
       *
       * @param data the string to extract the data from
       * @param offp a "pointer" (as a one-entry array) to the current offset into data
       * @return the next word of material from data
       */
      private static int streamtoword(byte[] data, int[] offp) {
          int word = 0;
          int off = offp[0];
  
          for (int i = 0; i < 4; i++) {
              word = (word << 8) | (data[off] & 0xff);
              off = (off + 1) % data.length;
          }
  
          offp[0] = off;
          return word;
      }
  
      /**
       * Initialize the Blowfish key schedule
       */
      private static void initializeKey() {
          pA = (int[]) P_ARRAY.clone();
          sB = (int[]) S_BOX.clone();
      }
  
      /**
       * Key the Blowfish cipher
       *
       * @param key an array containing the key
       */
      private static void key(byte[] key) {
          int[] koffp = {0};
          int[] lr = {0, 0};
  
          for (int i = 0; i < pA.length; i++) {
              pA[i] = pA[i] ^ streamtoword(key, koffp);
          }
          for (int i = 0; i < pA.length; i += 2) {
              encipher(lr, 0);
              pA[i] = lr[0];
              pA[i + 1] = lr[1];
          }
          for (int i = 0; i < sB.length; i += 2) {
              encipher(lr, 0);
              sB[i] = lr[0];
              sB[i + 1] = lr[1];
          }
      }
  
      /**
       * Perform the "enhanced key schedule"
       *
       * @param data salt information
       * @param key  password information
       */
      private static void enhancedKeySchedule(byte[] data, byte[] key) {
          int[] koffp = {0};
          int[] doffp = {0};
          int[] lr = {0, 0};
  
          for (int i = 0; i < pA.length; i++) {
              pA[i] = pA[i] ^ streamtoword(key, koffp);
          }
          for (int i = 0; i < pA.length; i += 2) {
              lr[0] ^= streamtoword(data, doffp);
              lr[1] ^= streamtoword(data, doffp);
              encipher(lr, 0);
              pA[i] = lr[0];
              pA[i + 1] = lr[1];
          }
  
          for (int i = 0; i < sB.length; i += 2) {
              lr[0] ^= streamtoword(data, doffp);
              lr[1] ^= streamtoword(data, doffp);
              encipher(lr, 0);
              sB[i] = lr[0];
              sB[i + 1] = lr[1];
          }
      }
  
      /**
       * Perform the central password hashing step in the bcrypt scheme
       *
       * @param password   the password to hash
       * @param salt       the binary salt to hash with the password
       * @param log_rounds the binary logarithm of the number of rounds of hashing to apply
       * @param cdata      the plaintext to encrypt
       * @return an array containing the binary hashed password
       * @throws IllegalArgumentException if log rounds is a bad value
       */
      private static byte[] bcrypt(byte[] password, byte[] salt, int log_rounds, int[] cdata) throws IllegalArgumentException {
  
          if (log_rounds < 4 || log_rounds > 30) {
              throw new IllegalArgumentException("Bad number of rounds");
          }
          final int rounds = 1 << log_rounds;
  
          initializeKey();
          enhancedKeySchedule(salt, password);
  
          for (int i = 0; i != rounds; i++) {
              key(password);
              key(salt);
          }
  
          int clen = cdata.length;
          for (int i = 0; i < 64; i++) {
              for (int j = 0; j < (clen >> 1); j++) {
                  encipher(cdata, j << 1);
              }
          }
  
          byte[] hash = new byte[clen * 4];
          for (int i = 0, j = 0; i < clen; i++) {
              hash[j++] = (byte) ((cdata[i] >> 24) & 0xff);
              hash[j++] = (byte) ((cdata[i] >> 16) & 0xff);
              hash[j++] = (byte) ((cdata[i] >> 8) & 0xff);
              hash[j++] = (byte) (cdata[i] & 0xff);
          }
          return hash;
      }
  
      /**
       * Creates a Hash from the given password using the specified algorithm.
       *
       * @param password   the password to hash
       * @param hash       the correct hash, null if hashing
       * @param saltLength the salt byte size
       * @param iterations the log rounds (e.g. 2^10)
       * @return the hashed password
       * @throws IllegalArgumentException if invalid salt or parameters
       * @deprecated use {@link #create(String, String, byte[], int)} instead.
       */
      @Deprecated
      public static String create(String password, String hash, int saltLength, int iterations) throws IllegalArgumentException {
          // Generate a salt of the specified length
          final byte[] salt = HashUtils.randomSalt(saltLength);
          return create(password, hash, salt, iterations);
      }
  
      /**
       * Creates a Hash from the given password using the specified algorithm.
       *
       * @param password   the password to hash
       * @param hash       the correct hash, null if hashing
       * @param salt       the salt bytes
       * @param iterations the log rounds (e.g. 2^10)
       * @return the hashed password
       * @throws IllegalArgumentException if invalid salt or parameters
       */
      public static String create(String password, String hash, byte[] salt, int iterations) throws IllegalArgumentException {
  
          if (password == null || password.isEmpty()) {
              throw new IllegalArgumentException("Password cannot be null or empty!");
          }
          if (password.length() > 72) {
              // 72 character password limit for bcrypt
              throw new IllegalArgumentException("Bcrypt cannot handle passwords longer than 72 characters. Sorry.");
          }
          if (salt == null) {
              salt = new byte[0];
          }
          if (iterations <= 0) {
              iterations = DEFAULT_LOG2_ROUNDS;
          }
  
          // we are creating a new hash
          // so we encode the salt first
          if (hash == null || hash.isEmpty()) {
              hash = formatSalt(salt, iterations);
          }
  
          char minor = (char) 0;
          int off = 0;
  
          // validate salt version
          if (hash.charAt(0) != '$' || hash.charAt(1) != '2') {
              throw new IllegalArgumentException("Invalid salt version");
          }
          if (hash.charAt(2) == '$') {
              off = 3;
          } else {
              // Different types of compatible blowfish minors.
              // "2a" - some implementations suffered from a very rare security flaw. current default for compatibility purposes.
              // "2y" - format specific to the crypt_blowfish BCrypt implementation, identical to "2a" in all but name.
              minor = hash.charAt(2);
              if (minor < 'a' || minor > 'z' || hash.charAt(3) != '$') {
                  throw new IllegalArgumentException("Invalid salt revision");
              }
              off = 4;
          }
  
          // Extract number of rounds
          if (hash.charAt(off + 2) > '$') {
              throw new IllegalArgumentException("Missing salt rounds");
          }
          final int rounds = Integer.parseInt(hash.substring(off, off + 2));
  
          // Extract real salt
          final int realSaltLength = formatSalt(salt, 10).length() - (off + 3);
          final String realSalt = hash.substring(off + 3, off + 3 + realSaltLength);
          final byte[] saltb = decodeBase64(realSalt, realSalt.length());
          byte[] passwordb;
          try {
              passwordb = (password + (minor >= 'a' ? "\000" : "")).getBytes("UTF-8");
          } catch (UnsupportedEncodingException uee) {
              throw new AssertionError("UTF-8 is not supported");
          }
  
          StringBuilder rs = new StringBuilder();
          rs.append("$2");
          if (minor >= 'a') {
              rs.append(minor);
          }
          rs.append("$");
          if (rounds < 10) {
              rs.append("0");
          }
          if (rounds > 30) {
              throw new IllegalArgumentException("rounds exceeds maximum (30)");
          }
          rs.append(Integer.toString(rounds));
          rs.append("$");
          rs.append(encodeBase64(saltb, saltb.length));
  
          final byte[] hashed = bcrypt(passwordb, saltb, rounds, (int[]) CIPHER.clone());
          rs.append(encodeBase64(hashed, CIPHER.length * 4 - 1));
  
          return rs.toString();
      }
  
      /**
       * Prepare a salt for use with the BCrypt.create() method.
       *
       * @param salt the salt
       * @param rounds the log rounds
       * @return an encoded salt value
       */
      private static String formatSalt(byte[] salt, int rounds) {
          try {
              StringBuilder sb = new StringBuilder();
              sb.append("$2y$");
              if (rounds < 10) {
                  sb.append("0");
              }
              sb.append(Integer.toString(rounds));
              sb.append("$");
              sb.append(encodeBase64(salt, salt.length));
              return sb.toString();
          } catch (Exception e) {
              // failed to base64 the random salt
              return "";
          }
      }
  }
  