base64.js

asp的bbs程序

var keyStr = "ABCDEFGHIJKLMNOP" +
             "QRSTUVWXYZabcdef" +
             "ghijklmnopqrstuv" +
             "wxyz0123456789+/" +
             "=";
function encode64(input) {
   input = escape(input);
   var output = "";
   var chr1, chr2, chr3 = "";
   var enc1, enc2, enc3, enc4 = "";
   var i = 0;

   do {
	  chr1 = input.charCodeAt(i++);
	  chr2 = input.charCodeAt(i++);
	  chr3 = input.charCodeAt(i++);

	  enc1 = chr1 >> 2;
	  enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
	  enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
	  enc4 = chr3 & 63;

	  if (isNaN(chr2)) {
		 enc3 = enc4 = 64;
	  } else if (isNaN(chr3)) {
		 enc4 = 64;
	  }

	  output = output +
		 keyStr.charAt(enc1) +
		 keyStr.charAt(enc2) +
		 keyStr.charAt(enc3) +
		 keyStr.charAt(enc4);
	  chr1 = chr2 = chr3 = "";
	  enc1 = enc2 = enc3 = enc4 = "";
   } while (i < input.length);

   return output;
}
function decode64 (input) {
   var output = "";
   var chr1, chr2, chr3 = "";
   var enc1, enc2, enc3, enc4 = "";
   var i = 0;

   // remove all characters that are not A-Z, a-z, 0-9, +, /, or =
   var base64test = /[^A-Za-z0-9\+\/\=]/g;
   if (base64test.exec(input)) {
	  alert("There were invalid base64 characters in the input text.\n" +
			"Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='\n" +
			"Expect errors in decoding.");
   }
   input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

   do {
	  enc1 = keyStr.indexOf(input.charAt(i++));
	  enc2 = keyStr.indexOf(input.charAt(i++));
	  enc3 = keyStr.indexOf(input.charAt(i++));
	  enc4 = keyStr.indexOf(input.charAt(i++));

	  chr1 = (enc1 << 2) | (enc2 >> 4);
	  chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
	  chr3 = ((enc3 & 3) << 6) | enc4;

	  output = output + String.fromCharCode(chr1);

	  if (enc3 != 64) {
		 output = output + String.fromCharCode(chr2);
	  }
	  if (enc4 != 64) {
		 output = output + String.fromCharCode(chr3);
	  }

	  chr1 = chr2 = chr3 = "";
	  enc1 = enc2 = enc3 = enc4 = "";

   } while (i < input.length);

   return unescape(output);
}

function processUrl (str) {
	//location.href = decode64(str);
	window.open(decode64(str));
	return false;
}

function displayUrl (th, str) {
   if (th.onmouseout) return false;
   th.href = decode64(str);
   th.onmouseout = function () {
	  window.status = '';
   };
   return true;
}