货无忧
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 

93 lines
2.9 KiB

"use strict";
const Base64 = function() {
let _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
this.encode = function(input) {
var output = "";
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0;
input = _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 + _keyStr.charAt(enc1) + _keyStr.charAt(enc2) + _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
}
return output;
};
this.decode = function(input) {
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
while (i < input.length) {
enc1 = _keyStr.indexOf(input.charAt(i++));
enc2 = _keyStr.indexOf(input.charAt(i++));
enc3 = _keyStr.indexOf(input.charAt(i++));
enc4 = _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 = _utf8_decode(output);
return output;
};
let _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;
};
let _utf8_decode = function(utftext) {
var string = "";
var i = 0;
var c = c1 = c2 = 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;
};
};
const Base64$1 = new Base64();
exports.Base64 = Base64$1;