![SHA-256 简介及 C# 和 js 实现[加密知多少系列]](/static/background/5.jpg "SHA-256 简介及 C# 和 js 实现[加密知多少系列]")
〇、简介
绝对安全的加密算法之一。
SHA256 其实就是一个哈希函数。哈希函数又称散列算法，是一种从任何一种数据中创建小的数字“指纹”的方法。散列函数把消息或数据压缩成摘要，使得数据量变小，将数据的格式固定下来。该函数将数据打乱混合，重新创建一个叫做散列值（或哈希值）的指纹。散列值通常用一个短的随机字母和数字组成的字符串来代表。关于哈希算法可以参考：Hash算法总结
对于任意长度的消息，SHA256 都会产生一个 256bit 长的哈希值，称作消息摘要。这个摘要相当于是个长度为 32 个字节的数组，通常用一个长度为 64 的十六进制字符串来表示。
一、C# 语言实现
// 测试
string jiamihx = SecuritySHA256.SHA256EncryptString("TestString测试"; // ede38cb25c21cea386a6b7a105a8cececfbdd10abecddd9c155a274d3baf2272
string jiamihX = SecuritySHA256.SHA256EncryptString("TestString测试", true; // EDE38CB25C21CEA386A6B7A105A8CECECFBDD10ABECDDD9C155A274D3BAF2272
byte[] jiamihbyte = SecuritySHA256.SHA256EncryptByte("TestString测试"; // byte[32]
using System.Security.Cryptography;
/// <summary>
/// SHA256加密，返回字符串
/// </summary>
/// <param name="deseninstr">待加密字符串</param>
/// <param name="isupper">false:小写 true:大写</param>
/// <returns></returns>
public static string SHA256EncryptString(string deseninstr, bool isupper = false
{
byte[] bytes = Encoding.UTF8.GetBytes(deseninstr;
using (var mySHA256 = SHA256Managed.Create(
{
byte[] hash = mySHA256.ComputeHash(bytes;
StringBuilder builder = new StringBuilder(;
for (int i = 0; i < hash.Length; i++
{
builder.Append(hash[i].ToString(isupper?"X2":"x2";
}
return builder.ToString(;
}
}
/// <summary>
/// SHA256加密，返回字节数组
/// </summary>
/// <param name="deseninstr">待加密字符串</param>
/// <returns>加密数组</returns>
public static Byte[] SHA256EncryptByte(string deseninstr
{
using (var mySHA256 = SHA256Managed.Create(
{
byte[] deseninbyte = Encoding.UTF8.GetBytes(deseninstr;
byte[] EncryptBytes = mySHA256.ComputeHash(deseninbyte;
return EncryptBytes;
}
}二、js 语言实现
1、引用第三方库 crypto-js 实现加密
// 引入 js 库
<script src="http://cdn.bootcdn.net/ajax/libs/crypto-js/4.0.0/crypto-js.js"></script>
// npm 方式引入
>npm install crypto-js
// 加密操作
let encryptpk = CryptoJS.SHA256("TestString测试".toString(;
console.log("加密后:",encryptpk;2、纯 js 方式加密
// 调用方法 message( 查看测试结果
function message( {
var data_de1 = SHA256("TestString测试", false
console.log(data_de1; // ede38cb25c21cea386a6b7a105a8cececfbdd10abecddd9c155a274d3baf2272
var data_de2 = SHA256("TestString测试", true
console.log(data_de2; // EDE38CB25C21CEA386A6B7A105A8CECECFBDD10ABECDDD9C155A274D3BAF2272
}
// 纯 js 加密方法
function Sha256Encrypt(encrypt_content, isupper = false {
const chrsz = 8
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 = isupper ? '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
}
encrypt_content = Utf8Encode(encrypt_content
return binb2hex(core_sha256(str2binb(encrypt_content, encrypt_content.length * chrsz
}