javascriptbase64加密解密

"utf-8">

function Base64() {// private property_keyStr &＃61; "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789&＃43;/&＃61;";// public method for encodingthis.encode &＃61; function (input) {var output &＃61; "";var chr1, chr2, chr3, enc1, enc2, enc3, enc4;var i &＃61; 0;input &＃61; _utf8_encode(input);while (i < input.length) {chr1 &＃61; input.charCodeAt(i&＃43;&＃43;);chr2 &＃61; input.charCodeAt(i&＃43;&＃43;);chr3 &＃61; input.charCodeAt(i&＃43;&＃43;);enc1 &＃61; chr1 >> 2;enc2 &＃61; ((chr1 & 3) <<4) | (chr2 >> 4);enc3 &＃61; ((chr2 & 15) <<2) | (chr3 >> 6);enc4 &＃61; chr3 & 63;if (isNaN(chr2)) {enc3 &＃61; enc4 &＃61; 64;} else if (isNaN(chr3)) {enc4 &＃61; 64;}output &＃61; output &＃43;_keyStr.charAt(enc1) &＃43; _keyStr.charAt(enc2) &＃43;_keyStr.charAt(enc3) &＃43; _keyStr.charAt(enc4);}return output;}// public method for decodingthis.decode &＃61; function (input) {var output &＃61; "";var chr1, chr2, chr3;var enc1, enc2, enc3, enc4;var i &＃61; 0;input &＃61; input.replace(/[^A-Za-z0-9\&＃43;\/\&＃61;]/g, "");while (i < input.length) {enc1 &＃61; _keyStr.indexOf(input.charAt(i&＃43;&＃43;));enc2 &＃61; _keyStr.indexOf(input.charAt(i&＃43;&＃43;));enc3 &＃61; _keyStr.indexOf(input.charAt(i&＃43;&＃43;));enc4 &＃61; _keyStr.indexOf(input.charAt(i&＃43;&＃43;));chr1 &＃61; (enc1 <<2) | (enc2 >> 4);chr2 &＃61; ((enc2 & 15) <<4) | (enc3 >> 2);chr3 &＃61; ((enc3 & 3) <<6) | enc4;output &＃61; output &＃43; String.fromCharCode(chr1);if (enc3 !&＃61; 64) {output &＃61; output &＃43; String.fromCharCode(chr2);}if (enc4 !&＃61; 64) {output &＃61; output &＃43; String.fromCharCode(chr3);}}output &＃61; _utf8_decode(output);return output;}// private method for UTF-8 encoding_utf8_encode &＃61; function (string) {string &＃61; string.replace(/\r\n/g,"\n");var utftext &＃61; "";for (var n &＃61; 0; n <string.length; n&＃43;&＃43;) {var c &＃61; string.charCodeAt(n);if (c <128) {utftext &＃43;&＃61; String.fromCharCode(c);} else if((c > 127) && (c <2048)) {utftext &＃43;&＃61; String.fromCharCode((c >> 6) | 192);utftext &＃43;&＃61; String.fromCharCode((c & 63) | 128);} else {utftext &＃43;&＃61; String.fromCharCode((c >> 12) | 224);utftext &＃43;&＃61; String.fromCharCode(((c >> 6) & 63) | 128);utftext &＃43;&＃61; String.fromCharCode((c & 63) | 128);}}return utftext;}// private method for UTF-8 decoding_utf8_decode &＃61; function (utftext) {var string &＃61; "";var i &＃61; 0;var c &＃61; c1 &＃61; c2 &＃61; 0;while ( i < utftext.length ) {c &＃61; utftext.charCodeAt(i);if (c <128) {string &＃43;&＃61; String.fromCharCode(c);i&＃43;&＃43;;} else if((c > 191) && (c <224)) {c2 &＃61; utftext.charCodeAt(i&＃43;1);string &＃43;&＃61; String.fromCharCode(((c & 31) <<6) | (c2 & 63));i &＃43;&＃61; 2;} else {c2 &＃61; utftext.charCodeAt(i&＃43;1);c3 &＃61; utftext.charCodeAt(i&＃43;2);string &＃43;&＃61; String.fromCharCode(((c & 15) <<12) | ((c2 & 63) <<6) | (c3 & 63));i &＃43;&＃61; 3;}}return string;}
}