Javascript實現的SHA-256密碼編譯演算法完整執行個體_基礎知識

本文執行個體講述了Javascript實現的SHA-256演算法。分享給大家供大家參考，具體如下：

/**** Secure Hash Algorithm (SHA256)* http://www.webtoolkit.info/** Original code by Angel Marin, Paul Johnston.***/function SHA256(s){  var chrsz = 8;  var hexcase = 0;  function safe_add (x, y) {    var lsw = (x & 0xFFFF) + (y & 0xFFFF);    var msw = (x >> 16) + (y >> 16) + (lsw >> 16);    return (msw << 16) | (lsw & 0xFFFF);  }  function S (X, n) { return ( X >>> n ) | (X << (32 - n)); }  function R (X, n) { return ( X >>> n ); }  function Ch(x, y, z) { return ((x & y) ^ ((~x) & z)); }  function Maj(x, y, z) { return ((x & y) ^ (x & z) ^ (y & z)); }  function Sigma0256(x) { return (S(x, 2) ^ S(x, 13) ^ S(x, 22)); }  function Sigma1256(x) { return (S(x, 6) ^ S(x, 11) ^ S(x, 25)); }  function Gamma0256(x) { return (S(x, 7) ^ S(x, 18) ^ R(x, 3)); }  function Gamma1256(x) { return (S(x, 17) ^ S(x, 19) ^ R(x, 10)); }  function core_sha256 (m, l) {    var K = new Array(0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 0xE49B69C1, 0xEFBE4786, 0xFC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x6CA6351, 0x14292967, 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2);    var HASH = new Array(0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19);    var W = new Array(64);    var a, b, c, d, e, f, g, h, i, j;    var T1, T2;    m[l >> 5] |= 0x80 << (24 - l % 32);    m[((l + 64 >> 9) << 4) + 15] = l;    for ( var i = 0; i<m.length; i+=16 ) {      a = HASH[0];      b = HASH[1];      c = HASH[2];      d = HASH[3];      e = HASH[4];      f = HASH[5];      g = HASH[6];      h = HASH[7];      for ( var j = 0; j<64; j++) {        if (j < 16) W[j] = m[j + i];        else W[j] = safe_add(safe_add(safe_add(Gamma1256(W[j - 2]), W[j - 7]), Gamma0256(W[j - 15])), W[j - 16]);        T1 = safe_add(safe_add(safe_add(safe_add(h, Sigma1256(e)), Ch(e, f, g)), K[j]), W[j]);        T2 = safe_add(Sigma0256(a), Maj(a, b, c));        h = g;        g = f;        f = e;        e = safe_add(d, T1);        d = c;        c = b;        b = a;        a = safe_add(T1, T2);      }      HASH[0] = safe_add(a, HASH[0]);      HASH[1] = safe_add(b, HASH[1]);      HASH[2] = safe_add(c, HASH[2]);      HASH[3] = safe_add(d, HASH[3]);      HASH[4] = safe_add(e, HASH[4]);      HASH[5] = safe_add(f, HASH[5]);      HASH[6] = safe_add(g, HASH[6]);      HASH[7] = safe_add(h, HASH[7]);    }    return HASH;  }  function str2binb (str) {    var bin = Array();    var mask = (1 << chrsz) - 1;    for(var i = 0; i < str.length * chrsz; i += chrsz) {      bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (24 - i%32);    }    return bin;  }  function Utf8Encode(string) {    string = string.replace(/\r\n/g,"\n");    var utftext = "";    for (var n = 0; n < string.length; n++) {      var c = string.charCodeAt(n);      if (c < 128) {        utftext += String.fromCharCode(c);      }      else if((c > 127) && (c < 2048)) {        utftext += String.fromCharCode((c >> 6) | 192);        utftext += String.fromCharCode((c & 63) | 128);      }      else {        utftext += String.fromCharCode((c >> 12) | 224);        utftext += String.fromCharCode(((c >> 6) & 63) | 128);        utftext += String.fromCharCode((c & 63) | 128);      }    }    return utftext;  }  function binb2hex (binarray) {    var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";    var str = "";    for(var i = 0; i < binarray.length * 4; i++) {      str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +      hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8 )) & 0xF);    }    return str;  }  s = Utf8Encode(s);  return binb2hex(core_sha256(str2binb(s), s.length * chrsz));}

更多關於JavaScript相關內容感興趣的讀者可查看本站專題：《JavaScript資料結構與演算法技巧總結》及《JavaScript數學運算用法總結》

希望本文所述對大家JavaScript程式設計有所協助。