js中实现base64加密、解密

╰+哭是因爲堅強的太久メ 2022-10-27 12:27 175阅读 0赞

//base64加密 解密
    
    /*  //1.加密
    var result = Base.encode('125中文');   //--> "MTI15Lit5paH"
    
    //2.解密
    var result2 = Base.decode(result);  //--> '125中文'
    */
    
    ~(function(root, factory) {
        if (ttypeof define === "function" && define.amd) {
            define([], factory);
        } else if (typeof module === "object" && module.exports) {
            module.exports = factory();
        } else {
            root.Base = factory();
        }
    } (this, function() {
        'use strict';
    
        function Base64() {
            // private property
            this._keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
        }
        //public method for encoding
        Base64.prototype.encode = function (input) {
            var output = "", chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;
            input = this._utf8_encode(input);
            while (i < input.length) {
                chr1 = input.charCodeAt(i++);
                chr2 = input.charCodeAt(i++);
                chr3 = input.charCodeAt(i++);
                enc1 = chr1 >> 2;
                enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                enc4 = chr3 & 63;
                if (isNaN(chr2)) {
                    enc3 = enc4 = 64;
                } else if (isNaN(chr3)) {
                    enc4 = 64;
                }
                output = output + this._keyStr.charAt(enc1) + this._keyStr.charAt(enc2) +
                        this._keyStr.charAt(enc3) + this._keyStr.charAt(enc4);
            }
            return output;
        }
    
        // public method for decoding
        Base64.prototype.decode = function (input) {
            var output = "", chr1, chr2, chr3, enc1, enc2, enc3, enc4, i = 0;
            input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
            while (i < input.length) {
                enc1 = this._keyStr.indexOf(input.charAt(i++));
                enc2 = this._keyStr.indexOf(input.charAt(i++));
                enc3 = this._keyStr.indexOf(input.charAt(i++));
                enc4 = this._keyStr.indexOf(input.charAt(i++));
                chr1 = (enc1 << 2) | (enc2 >> 4);
                chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                chr3 = ((enc3 & 3) << 6) | enc4;
                output = output + String.fromCharCode(chr1);
                if (enc3 != 64) {
                    output = output + String.fromCharCode(chr2);
                }
                if (enc4 != 64) {
                    output = output + String.fromCharCode(chr3);
                }
            }
            output = this._utf8_decode(output);
            return output;
        }
    
        //private method for UTF-8 encoding
        Base64.prototype._utf8_encode = function (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;
        }
    
        // private method for UTF-8 decoding
        Base64.prototype._utf8_decode = function (utftext) {
            var string = "", i = 0, c = 0, c1 = 0, c2 = 0, c3 = 0;
            while (i < utftext.length) {
                c = utftext.charCodeAt(i);
                if (c < 128) {
                    string += String.fromCharCode(c);
                    i++;
                } else if ((c > 191) && (c < 224)) {
                    c2 = utftext.charCodeAt(i+1);
                    string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                    i += 2;
                } else {
                    c2 = utftext.charCodeAt(i+1);
                    c3 = utftext.charCodeAt(i+2);
                    string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                    i += 3;
                }
            }
            return string;
        }
    
        var Base = new Base64();
    
        return Base;
    }));