使用base64加密实现前后端数据加密传输的方法

具体方法如下：

var keyStr = "ABCDEFGHIJKLMNOP"+"QRSTUVWXYZabcdef"+"ghijklmnopqrstuv"+"wxyz0123456789+/=";
//进行base64加密 input为参数，output为返回参数
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; 
}