139 lines
4.6 KiB
JavaScript
139 lines
4.6 KiB
JavaScript
/**
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*
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* Base64 encode / decode
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* 文字采用UTF-8方式进行Base64编码
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*
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*/
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function Base64() {
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// private property
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_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
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// public method for encoding
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this.encode = function (input) {
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var output=new Array();
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var chr1, chr2, chr3;
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var enc1, enc2, enc3, enc4;
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var i = 0;
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input = _utf8_encode(input);
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while (i < input.length)
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{
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chr1 = input[i++];
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chr2 = input[i++];
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chr3 = input[i++];
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enc1 = chr1 >> 2;
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enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
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enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
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enc4 = chr3 & 63;
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if (isNaN(chr2)) {
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enc3 = enc4 = 64;
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} else if (isNaN(chr3)) {
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enc4 = 64;
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}
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output.push(_keyStr.charAt(enc1) + _keyStr.charAt(enc2) + _keyStr.charAt(enc3) + _keyStr.charAt(enc4));
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}
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return output.join('');
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}
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// public method for decoding
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this.decode = function (input) {
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var output = "";
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var chr1, chr2, chr3;
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var enc1, enc2, enc3, enc4;
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var i = 0;
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input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
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while (i < input.length) {
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enc1 = _keyStr.indexOf(input.charAt(i++));
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enc2 = _keyStr.indexOf(input.charAt(i++));
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enc3 = _keyStr.indexOf(input.charAt(i++));
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enc4 = _keyStr.indexOf(input.charAt(i++));
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chr1 = (enc1 << 2) | (enc2 >> 4);
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chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
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chr3 = ((enc3 & 3) << 6) | enc4;
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output = output + String.fromCharCode(chr1);
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if (enc3 != 64) {
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output = output + String.fromCharCode(chr2);
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}
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if (enc4 != 64) {
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output = output + String.fromCharCode(chr3);
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}
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}
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output = _utf8_decode(output);
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return output;
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}
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// private method for UTF-8 encoding
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_utf8_encode = function (string) {
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string = string.replace(/\r\n/g,"\n");
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var utftext = new Array();
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var utftextlen=0;
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for (var n = 0; n < string.length; n++) {
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var c = string.charCodeAt(n);
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if (c < 128) {
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utftext[utftextlen++] = c;
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} else if((c > 127) && (c < 2048)) {
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utftext[utftextlen++] = (c >> 6) | 192;
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utftext[utftextlen++] = (c & 63) | 128;
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} else {
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utftext[utftextlen++] = (c >> 12) | 224;
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utftext[utftextlen++] = ((c >> 6) & 63) | 128;
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utftext[utftextlen++] = (c & 63) | 128;
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}
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}
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return utftext;
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}
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// private method for UTF-8 decoding
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_utf8_decode = function (utftext) {
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var string = "";
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var i = 0;
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var c = c1 = c2 = 0;
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while ( i < utftext.length ) {
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c = utftext.charCodeAt(i);
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if (c < 128) {
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string += String.fromCharCode(c);
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i++;
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} else if((c > 191) && (c < 224)) {
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c2 = utftext.charCodeAt(i+1);
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string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
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i += 2;
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} else {
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c2 = utftext.charCodeAt(i+1);
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c3 = utftext.charCodeAt(i+2);
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string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
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i += 3;
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}
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}
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return string;
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}
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_exchange_character = function(charArray){
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charArray=charArray.split("");
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for (var i = 0; i < charArray.length; i++)
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{
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// 互换相邻的字符
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if (i > 0 && i % 2 == 0)
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{
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var c = charArray[i];
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charArray[i] = charArray[i - 1];
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charArray[i - 1] = c;
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}
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}
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return charArray.join("");
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}
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//参数需要绕过防火墙可使用此方法加密
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this.encodePostParam = function(input) {
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input=this.encode(input).split("").reverse().join("");
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return _exchange_character(input);
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}
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this.decodePostParam = function(input) {
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input=_exchange_character(input).split("").reverse().join("");
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return this.decode(input);
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}
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}
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