SHA256安全散列算法的Javascript实现

SHA256算法原理详解:
https://blog.csdn.net/u011583927/article/details/80905740

在网上找的javascript实现，代码作者信息： http://www.webtoolkit.info/
Original code by Angel Marin, Paul Johnston.
实现步骤1：复制最下面的代码新建js文件，sha256.js
步骤2：在使用的页面index.js中引入

index.js:

import {SHA256} from './sha256'
let a='123456'
console.log('SHA256:',SHA256(a))
//结果SHA256:8d969eef6ecad3c29a3a629280e686cf0c3f5d5a86aff3ca12020c923adc6c92

sha256.js：

export function SHA256(s) {
  const chrsz = 8
  const hexcase = 0

  function safe_add(x, y) {
    const lsw = (x & 0xFFFF) + (y & 0xFFFF)
    const 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) {
    const K = [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]
    const HASH = [0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19]
    const W = new Array(64)
    let a, b, c, d, e, f, g, h, i, j
    let T1, T2
    m[l >> 5] |= 0x80 << (24 - l % 32)
    m[((l + 64 >> 9) << 4) + 15] = l
    for (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 (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) {
    const bin = []
    const mask = (1 << chrsz) - 1
    for (let 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')
    let utfText = ''
    for (let n = 0; n < string.length; n++) {
      const 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) {
    const hex_tab = hexcase ? '0123456789ABCDEF' : '0123456789abcdef'
    let str = ''
    for (let 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))
}