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2009年4月4日 周六 22:18 <HTML> <HEAD> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <TITLE>文本加密</TITLE> <SCRIPT LANGUAGE="JavaScript"> function TEAencrypt(plaintext, password) { if (plaintext.length == 0) return(‘‘); // nothing to encrypt // ‘escape‘ plaintext so chars outside ISO-8859-1 work in single-byte packing, but keep // spaces as spaces (not ‘%20‘) so encrypted text doesn‘t grow too long (quick & dirty) var asciitext = escape(plaintext).replace(/%20/g,‘ ‘); var v = strToLongs(asciitext); // convert string to array of longs if (v.length <= 1) v[1] = 0; // algorithm doesn‘t work for n<2 so fudge by adding a null var k = strToLongs(password.slice(0,16)); // simply convert first 16 chars of password as key var n = v.length; var z = v[n-1], y = v[0], delta = 0x9E3779B9; var mx, e, q = Math.floor(6 + 52/n), sum = 0; while (q-- > 0) { // 6 + 52/n operations gives between 6 & 32 mixes on each word sum += delta; e = sum>>>2 & 3; for (var p = 0; p < n; p++) { y = v[(p+1)%n]; mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z); z = v[p] += mx; } } var ciphertext = longsToStr(v); return escCtrlCh(ciphertext); } // // TEAdecrypt: Use Corrected Block TEA to decrypt ciphertext using password // function TEAdecrypt(ciphertext, password) { if (ciphertext.length == 0) return(‘‘); var v = strToLongs(unescCtrlCh(ciphertext)); var k = strToLongs(password.slice(0,16)); var n = v.length; var z = v[n-1], y = v[0], delta = 0x9E3779B9; var mx, e, q = Math.floor(6 + 52/n), sum = q*delta; while (sum != 0) { e = sum>>>2 & 3; for (var p = n-1; p >= 0; p--) { z = v[p>0 ? p-1 : n-1]; mx = (z>>>5 ^ y<<2) + (y>>>3 ^ z<<4) ^ (sum^y) + (k[p&3 ^ e] ^ z); y = v[p] -= mx; } sum -= delta; } var plaintext = longsToStr(v); // strip trailing null chars resulting from filling 4-char blocks: plaintext = plaintext.replace(/\0+$/,‘‘); return unescape(plaintext); } // supporting functions function strToLongs(s) { // convert string to array of longs, each containing 4 chars // note chars must be within ISO-8859-1 (with Unicode code-point < 256) to fit 4/long var l = new Array(Math.ceil(s.length/4)); for (var i=0; i<l.length; i++) { // note little-endian encoding - endianness is irrelevant as long as // it is the same in longsToStr() l[i] = s.charCodeAt(i*4) + (s.charCodeAt(i*4+1)<<8) + (s.charCodeAt(i*4+2)<<16) + (s.charCodeAt(i*4+3)<<24); } return l; // note running off the end of the string generates nulls since } // bitwise operators treat NaN as 0 function longsToStr(l) { // convert array of longs back to string var a = new Array(l.length); for (var i=0; i<l.length; i++) { a[i] = String.fromCharCode(l[i] & 0xFF, l[i]>>>8 & 0xFF, l[i]>>>16 & 0xFF, l[i]>>>24 & 0xFF); } return a.join(‘‘); // use Array.join() rather than repeated string appends for efficiency } function escCtrlCh(str) { // escape control chars etc which might cause problems with encrypted texts return str.replace(/[\0\t\n\v\f\r\xa0‘"!]/g, function(c) { return ‘!‘ + c.charCodeAt(0) + ‘!‘; }); } function unescCtrlCh(str) { // unescape potentially problematic nulls and control characters return str.replace(/!\d\d?\d?!/g, function(c) { return String.fromCharCode(c.slice(1,-1)); }); } var Base64 = function(){} Base64.encodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; Base64.decodeChars = new Array( - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, - 1, 62, - 1, - 1, - 1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, - 1, - 1, - 1, - 1, - 1, - 1, - 1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, - 1, - 1, - 1, - 1, - 1, - 1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, - 1, - 1, - 1, - 1, - 1); Base64.encode = function(str) { var out, i, len; var c1, c2, c3; len = str.length; i = 0; out = ""; while (i < len) { c1 = str.charCodeAt(i++) & 0xff; if (i == len) { out += Base64.encodeChars.charAt(c1 >> 2); out += Base64.encodeChars.charAt((c1 & 0x3) << 4); out += "=="; break; } c2 = str.charCodeAt(i++); if (i == len) { out += Base64.encodeChars.charAt(c1 >> 2); out += Base64.encodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)); out += Base64.encodeChars.charAt((c2 & 0xF) << 2); out += "="; break; } c3 = str.charCodeAt(i++); out += Base64.encodeChars.charAt(c1 >> 2); out += Base64.encodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4)) ; out += Base64.encodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6)) ; out += Base64.encodeChars.charAt(c3 & 0x3F); } return out; } Base64.decode = function(str) { var c1, c2, c3, c4; var i, len, out; len = str.length; i = 0; out = ""; while (i < len) { /* c1 */ do { c1 = Base64.decodeChars[str.charCodeAt(i++) & 0xff]; } while (i < len && c1 == - 1); if (c1 == - 1) break; /* c2 */ do { c2 = Base64.decodeChars[str.charCodeAt(i++) & 0xff]; } while (i < len && c2 == - 1); if (c2 == - 1) break; out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4)); /* c3 */ do { c3 = str.charCodeAt(i++) & 0xff; if (c3 == 61) return out; c3 = Base64.decodeChars[c3]; } while (i < len && c3 == - 1); if (c3 == - 1) break; out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2)); /* c4 */ do { c4 = str.charCodeAt(i++) & 0xff; if (c4 == 61) return out; c4 = Base64.decodeChars[c4]; } while (i < len && c4 == - 1); if (c4 == - 1) break; out += String.fromCharCode(((c3 & 0x03) << 6) | c4); } return out; } Base64.utf16to8 = function(str) { var out, i, len, c; out = ""; len = str.length; for (i = 0; i < len; i++) { c = str.charCodeAt(i); if ((c >= 0x0001) && (c <= 0x007F)) { out += str.charAt(i); } else if (c > 0x07FF) { out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F)); out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F)); out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F)); } else { out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F)); out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F)); } } return out; } Base64.utf8to16 = function(str) { var out, i, len, c; var char2, char3; out = ""; len = str.length; i = 0; while (i < len) { c = str.charCodeAt(i++); switch (c >> 4) { case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: // 0xxxxxxx out += str.charAt(i - 1); break; case 12: case 13: // 110x xxxx 10xx xxxx char2 = str.charCodeAt(i++); out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F)); break; case 14: // 1110 xxxx 10xx xxxx 10xx xxxx char2 = str.charCodeAt(i++); char3 = str.charCodeAt(i++); out += String.fromCharCode(((c & 0x0F) << 12) | ((char2 & 0x3F) << 6) | ((char3 & 0x3F) << 0)); break; } } return out; } function doSecure() { var str = TEAencrypt(document.getElementById("txtUnsecure").value, document.getElementById("txtPassw").value); document.getElementById("txtSecure").value = Base64.encode(Base64.utf16to8(str)); } function doUnsecure() { var str = Base64.utf8to16(Base64.decode(document.getElementById("txtSecure").value)); document.getElementById("txtUnsecure").value = TEAdecrypt(str, document.getElementById("txtPassw").value); } </script> </HEAD> <BODY > <center> <table border=1 width="571"> <tr> <td> <form name=frmSecurity> <p><font color=#ff0000>密码:</font> <input type=password id=txtPassw size=20 value=""> <table border=0> <tr> <p><font color=#0000ff>原文</font> </tr> <tr> <textarea rows=20 id=txtUnsecure cols=120 wrap=virtual>我是一个美女！</textarea> </tr> <tr align=center> <input type=button value=" 加密 " name=btnSecure onclick="doSecure()"> <br> <input type=button value=" 解密 " name=btnUnsecure onclick="doUnsecure()"> </tr> <tr> <p><font color=#0000ff>加密之后</font> </tr> <tr> <textarea rows=20 id=txtSecure cols=120 wrap=virtual></textarea></td> </tr> </table> </form> </td> </tr> </table> </center> </BODY></HTML>
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原文地址：http://www.cnblogs.com/yasepix/p/5138239.html
