<script type="text/javascript">
function base64_decode( data ) {
// Decodes string using MIME base64 algorithm
//
// version: 905.3122
// discuss at:
// + original by: Tyler Akins ()
// + improved by: Thunder.m
// + input by: Aman Gupta
// + improved by: Kevin van Zonneveld ()
// + bugfixed by: Onno Marsman
// + bugfixed by: Pellentesque Malesuada
// + improved by: Kevin van Zonneveld ()
// + input by: Brett Zamir ()
// + bugfixed by: Kevin van Zonneveld ()
// - depends on: utf8_decode
// * example 1: base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
// * returns 1: 'Kevin van Zonneveld'
// mozilla has this native
// - but breaks in 2.0.0.12!
//if (typeof this.window['btoa'] == 'function') {
// return btoa(data);
//}
var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, dec = "", tmp_arr = [];
if (!data) {
return data;
}
data += '';
do { // unpack four hexets into three octets using index points in b64
h1 = b64.indexOf(data.charAt(i++));
h2 = b64.indexOf(data.charAt(i++));
h3 = b64.indexOf(data.charAt(i++));
h4 = b64.indexOf(data.charAt(i++));
bits = h1<<18 | h2<<12 | h3<<6 | h4;
o1 = bits>>16 & 0xff;
o2 = bits>>8 & 0xff;
o3 = bits & 0xff;
if (h3 == 64) {
tmp_arr[ac++] = String.fromCharCode(o1);
} else if (h4 == 64) {
tmp_arr[ac++] = String.fromCharCode(o1, o2);
} else {
tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
}
} while (i < data.length);
dec = tmp_arr.join('');
dec = this.utf8_decode(dec);
return dec;
}
function base64_encode( data ) {
// Encodes string using MIME base64 algorithm
//
// version: 905.2617
// discuss at:
// + original by: Tyler Akins ()
// + improved by: Bayron Guevara
// + improved by: Thunder.m
// + improved by: Kevin van Zonneveld ()
// + bugfixed by: Pellentesque Malesuada
// + improved by: Kevin van Zonneveld ()
// - depends on: utf8_encode
// * example 1: base64_encode('Kevin van Zonneveld');
// * returns 1: 'S2V2aW4gdmFuIFpvbm5ldmVsZA=='
// mozilla has this native
// - but breaks in 2.0.0.12!
//if (typeof this.window['atob'] == 'function') {
// return atob(data);
//}
var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
var o1, o2, o3, h1, h2, h3, h4, bits, i = 0, ac = 0, enc="", tmp_arr = [];
if (!data) {
return data;
}
data = this.utf8_encode(data+'');
do { // pack three octets into four hexets
o1 = data.charCodeAt(i++);
o2 = data.charCodeAt(i++);
o3 = data.charCodeAt(i++);
bits = o1<<16 | o2<<8 | o3;
h1 = bits>>18 & 0x3f;
h2 = bits>>12 & 0x3f;
h3 = bits>>6 & 0x3f;
h4 = bits & 0x3f;
// use hexets to index into b64, and append result to encoded string
tmp_arr[ac++] = b64.charAt(h1) + b64.charAt(h2) + b64.charAt(h3) + b64.charAt(h4);
} while (i < data.length);
enc = tmp_arr.join('');
switch( data.length % 3 ){
case 1:
enc = enc.slice(0, -2) + '==';
break;
case 2:
enc = enc.slice(0, -1) + '=';
break;
}
return enc;
}
function utf8_encode ( argString ) {
// Encodes an ISO-8859-1 string to UTF-8
//
// version: 905.1217
// discuss at:
// + original by: Webtoolkit.info ()
// + improved by: Kevin van Zonneveld ()
// + improved by: sowberry
// + tweaked by: Jack
// + bugfixed by: Onno Marsman
// + improved by: Yves Sucaet
// + bugfixed by: Onno Marsman
// * example 1: utf8_encode('Kevin van Zonneveld');
// * returns 1: 'Kevin van Zonneveld'
var string = (argString+'').replace(/\r\n/g, "\n").replace(/\r/g, "\n");
var utftext = "";
var start, end;
var stringl = 0;
start = end = 0;
stringl = string.length;
for (var n = 0; n < stringl; n++) {
var c1 = string.charCodeAt(n);
var enc = null;
if (c1 < 128) {
end++;
} else if((c1 > 127) && (c1 < 2048)) {
enc = String.fromCharCode((c1 >> 6) | 192) + String.fromCharCode((c1 & 63) | 128);
} else {
enc = String.fromCharCode((c1 >> 12) | 224) + String.fromCharCode(((c1 >> 6) & 63) | 128) + String.fromCharCode((c1 & 63) | 128);
}
if (enc !== null) {
if (end > start) {
utftext += string.substring(start, end);
}
utftext += enc;
start = end = n+1;
}
}
if (end > start) {
utftext += string.substring(start, string.length);
}
return utftext;
}
function utf8_decode ( str_data ) {
// Converts a UTF-8 encoded string to ISO-8859-1
//
// version: 905.3122
// discuss at:
// + original by: Webtoolkit.info ()
// + input by: Aman Gupta
// + improved by: Kevin van Zonneveld ()
// + improved by: Norman "zEh" Fuchs
// + bugfixed by: hitwork
// + bugfixed by: Onno Marsman
// + input by: Brett Zamir ()
// + bugfixed by: Kevin van Zonneveld ()
// * example 1: utf8_decode('Kevin van Zonneveld');
// * returns 1: 'Kevin van Zonneveld'
var tmp_arr = [], i = 0, ac = 0, c1 = 0, c2 = 0, c3 = 0;
str_data += '';
while ( i < str_data.length ) {
c1 = str_data.charCodeAt(i);
if (c1 < 128) {
tmp_arr[ac++] = String.fromCharCode(c1);
i++;
} else if ((c1 > 191) && (c1 < 224)) {
c2 = str_data.charCodeAt(i+1);
tmp_arr[ac++] = String.fromCharCode(((c1 & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = str_data.charCodeAt(i+1);
c3 = str_data.charCodeAt(i+2);
tmp_arr[ac++] = String.fromCharCode(((c1 & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return tmp_arr.join('');
}
</script>
base64_decode 依赖 utf8_decode ，base64_encode 依赖 utf8_encode。
PHP2JS是开源项目，是将PHP的部分函数实现到JavaScript。
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