// base64���ܿ�ʼ var keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv" + "wxyz0123456789+/" + "="; function encode64(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; var base64test = /[^A-Za-z0-9\+\/\=]/g; if (base64test.exec(input)) { console.log("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); } //// base64���ܽ���