103 lines
3.5 KiB
JavaScript
103 lines
3.5 KiB
JavaScript
function Base64() {
|
|
|
|
// private property
|
|
_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
|
|
|
|
// public method for encoding
|
|
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;
|
|
}
|
|
|
|
// public method for decoding
|
|
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;
|
|
}
|
|
|
|
// private method for UTF-8 encoding
|
|
_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
|
|
_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;
|
|
}
|
|
} |