我們平時在網上尋找資源時,都看到一些網站裏特別標明分開,用迅雷下載;用旋風下載;用快車下載等這些標籤,如迅雷,我們常常會見到類似於如下的鏈接地址: thunder://QUFodHRwOi8vZG93bmxvYWRzLmFwcG1hcnRzLmNvbS9hcHBtYXJ0cy5leGVaWg== ,當你點擊該地址後,如果你的系統裏安裝了迅雷軟件,迅雷識別它自己的協議頭“thunder://”,就彈出詢問是否執行下載,因爲它可以正確解析這樣的地址。
現假設有一軟件下載地址:http://downloads.appmarts.com/appmarts.exe。下面來說明一下整個地址的加密過程:
迅雷:
在完整的下載鏈接前加“AA”(不包括引號),後加“ZZ”(不包括引號),得到:
AAhttp://downloads.appmarts.com/appmarts.exeZZ
然後再用BASE64算法進行加密,得到:
QUFodHRwOi8vZG93bmxvYWRzLmFwcG1hcnRzLmNvbS9hcHBtYXJ0cy5leGVaWg==
最後在前面加上迅雷自己的協議就搞定:thunder://QUFodHRwOi8vZG93bmxvYWRzLmFwcG1hcnRzLmNvbS9hcHBtYXJ0cy5leGVaWg==
快車:
快車地址加密算法是大同小異,它使用了同樣的原理,只是的原完整的下載鏈接前後各加上“[FLASHGET]”(不包括引號),
然後同樣使用BASE64算法進行加密,加密後在前面再加上快車自己的協議頭:
flashget://W0ZMQVNIR0VUXWh0dHA6Ly9kb3dubG9hZHMuYXBwbWFydHMuY29tL2FwcG1hcnRzLmV4ZVtGTEFTSEdFVF0=
旋風:
旋風的加密法比迅雷和快車簡單了第一個步取,就是直接將原下載鏈進行BASE64算法加密,然後加上協議頭:“qdl://”,即可:
qqdl://aHR0cDovL2Rvd25sb2Fkcy5hcHBtYXJ0cy5jb20vYXBwbWFydHMuZXhl
附Javascript的BASE64加密/解密函數和獲取對應加密鏈接地址方法:
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var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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var base64DecodeChars = new Array(
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
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52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
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-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
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-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
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41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);
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function Base64Encode(str) {
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var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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var out, i, len;
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var c1, c2, c3;
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len = str.length;
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i = 0;
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out = "";
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while (i < len) {
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c1 = str.charCodeAt(i++) & 0xff;
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if (i == len) {
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out += base64EncodeChars.charAt(c1 >> 2);
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out += base64EncodeChars.charAt((c1 & 0x3) << 4);
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out += "==";
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break;
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}
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c2 = str.charCodeAt(i++);
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if (i == len) {
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out += base64EncodeChars.charAt(c1 >> 2);
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out += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
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out += base64EncodeChars.charAt((c2 & 0xF) << 2);
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out += "=";
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break;
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}
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c3 = str.charCodeAt(i++);
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out += base64EncodeChars.charAt(c1 >> 2);
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out += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));
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out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));
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out += base64EncodeChars.charAt(c3 & 0x3F);
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}
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return out;
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}
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function Base64Decode(str) {
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var c1, c2, c3, c4;
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var i, len, out;
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len = str.length;
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i = 0;
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out = "";
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while (i < len) {
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do {
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c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
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} while (i < len && c1 == -1);
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if (c1 == -1) break;
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do {
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c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];
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} while (i < len && c2 == -1);
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if (c2 == -1) break;
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out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));
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do {
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c3 = str.charCodeAt(i++) & 0xff;
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if (c3 == 61) return out;
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c3 = base64DecodeChars[c3];
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} while (i < len && c3 == -1);
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if (c3 == -1) break;
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out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));
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do {
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c4 = str.charCodeAt(i++) & 0xff;
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if (c4 == 61) return out;
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c4 = base64DecodeChars[c4];
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} while (i < len && c4 == -1);
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if (c4 == -1) break;
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out += String.fromCharCode(((c3 & 0x03) << 6) | c4);
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}
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return out;
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}
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function GetThunderUrl(url) {
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var thunder = "AA" + url + "ZZ";
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thunder = "thunder://" + Base64Encode(thunder);
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return thunder;
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}
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function GetQQDownloadUrl(url) {
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var qqDownload = url;
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qqDownload = "qqdl://" + Base64Encode(qqDownload);
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return qqDownload;
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}
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function GetFlashgetUrl(url) {
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var flashget = "[FLASHGET]" + url + "[FLASHGET]";
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flashget = "flashget://" + Base64Encode(flashget);
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return flashget;
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}