14.【原创】小程序使用sha256加密

最近公司项目的微信小程序有使用到sha256的加密方式，后端采用的是node.js的加密模块实现的，网上找了蛮久关于sha256的加密模块，都不是很好用，有些模块带中文内容计算出来的内容与服务器端无法匹配上，后来几经周转找到了一个合适的，特此记录。

服务器端加密方式：

// 服务器加密流程
function serverSha256(sign_str) {
    var crypto = require("crypto");
    var sha1 = crypto.createHash('sha256');
    sha1.update(new Buffer(sign_str, "utf-8"));
    return sha1.digest('hex').toLowerCase();
}

// 客户端加密流程
function clientSha256(sign_str) {
    var sha256 = require("../utils/sha256Two.js");
    return sha256.sha256_digest(sign_str);
}

小程序端加密算法(sha256Two.js)：

参考地址：https://www.jb51.net/article/79043.htm

/**
*
* 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));
}

module.exports = {
    sha256_digest: SHA256
}

　　

希望能帮到有需要的同学。