JS实现的base64加密解密操作示例

更新时间：2020-07-06 02:24:01 作者：startmvc

本文实例讲述了JS实现的base64加密解密操作。分享给大家供大家参考，具体如下：<!DOCTYPEh

本文实例讲述了JS实现的base64加密解密操作。分享给大家供大家参考，具体如下：


<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>js base64加密解密</title>
</head>
<body>
<script>
// 创建Base64对象
var Base64 = {
 _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
 encode: function(e) {
 var t = "";
 var n, r, i, s, o, u, a;
 var f = 0;
 e = Base64._utf8_encode(e);
 while (f < e.length) {
 n = e.charCodeAt(f++);
 r = e.charCodeAt(f++);
 i = e.charCodeAt(f++);
 s = n >> 2;
 o = (n & 3) << 4 | r >> 4;
 u = (r & 15) << 2 | i >> 6;
 a = i & 63;
 if (isNaN(r)) {
 u = a = 64
 } else if (isNaN(i)) {
 a = 64
 }
 t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a)
 }
 return t
 },
 decode: function(e) {
 var t = "";
 var n, r, i;
 var s, o, u, a;
 var f = 0;
 e=e.replace(/[^A-Za-z0-9+/=]/g,"");
 while (f < e.length) {
 s = this._keyStr.indexOf(e.charAt(f++));
 o = this._keyStr.indexOf(e.charAt(f++));
 u = this._keyStr.indexOf(e.charAt(f++));
 a = this._keyStr.indexOf(e.charAt(f++));
 n = s << 2 | o >> 4;
 r = (o & 15) << 4 | u >> 2;
 i = (u & 3) << 6 | a;
 t = t + String.fromCharCode(n);
 if (u != 64) {
 t = t + String.fromCharCode(r)
 }
 if (a != 64) {
 t = t + String.fromCharCode(i)
 }
 }
 t = Base64._utf8_decode(t);
 return t
 },
 _utf8_encode: function(e) {
 e = e.replace(/rn/g, "n");
 var t = "";
 for (var n = 0; n < e.length; n++) {
 var r = e.charCodeAt(n);
 if (r < 128) {
 t += String.fromCharCode(r)
 } else if (r > 127 && r < 2048) {
 t += String.fromCharCode(r >> 6 | 192);
 t += String.fromCharCode(r & 63 | 128)
 } else {
 t += String.fromCharCode(r >> 12 | 224);
 t += String.fromCharCode(r >> 6 & 63 | 128);
 t += String.fromCharCode(r & 63 | 128)
 }
 }
 return t
 },
 _utf8_decode: function(e) {
 var t = "";
 var n = 0;
 var r = c1 = c2 = 0;
 while (n < e.length) {
 r = e.charCodeAt(n);
 if (r < 128) {
 t += String.fromCharCode(r);
 n++
 } else if (r > 191 && r < 224) {
 c2 = e.charCodeAt(n + 1);
 t += String.fromCharCode((r & 31) << 6 | c2 & 63);
 n += 2
 } else {
 c2 = e.charCodeAt(n + 1);
 c3 = e.charCodeAt(n + 2);
 t += String.fromCharCode((r & 15) << 12 | (c2 & 63) << 6 | c3 & 63);
 n += 3
 }
 }
 return t
 }
}
// 定义字符串
var string = 'Hello World!';
// 加密
var encodedString = Base64.encode(string);
console.log(encodedString); // 输出: "SGVsbG8gV29ybGQh"
// 解密
var decodedString = Base64.decode(encodedString);
console.log(decodedString); // 输出: "Hello World!"
</script>
</body>
</html>

运行结果：