登陆验证前对用户名和密码加密之后传输数据---base64加密

/** 
* 
*  Base64 encode / decode 
* 
* 
*/

function Base64() {

    // private property  
    _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

    // public method for encoding  
    this.encode = function (input) {
        var output = "";
        var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
        var i = 0;
        input = _utf8_encode(input);
        while (i < input.length) {
            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);
        }
        return output;
    }

    // public method for decoding  
    this.decode = function (input) {
        var output = "";
        var chr1, chr2, chr3;
        var enc1, enc2, enc3, enc4;
        var i = 0;
        input = input.replace(/[^A-Za-z0-9+/=]/g, "");
        while (i < input.length) {
            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);
            }
        }
        output = _utf8_decode(output);
        return output;
    }

    // private method for UTF-8 encoding  
    _utf8_encode = function (string) {
        string = string.replace(/
/g, "
");
        var utftext = "";
        for (var n = 0; n < string.length; n++) {
            var c = string.charCodeAt(n);
            if (c < 128) {
                utftext += String.fromCharCode(c);
            } else if ((c > 127) && (c < 2048)) {
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            } else {
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }

        }
        return utftext;
    }

    // private method for UTF-8 decoding  
    _utf8_decode = function (utftext) {
        var string = "";
        var i = 0;
        var c = c1 = c2 = 0;
        while (i < utftext.length) {
            c = utftext.charCodeAt(i);
            if (c < 128) {
                string += String.fromCharCode(c);
                i++;
            } else if ((c > 191) && (c < 224)) {
                c2 = utftext.charCodeAt(i + 1);
                string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                i += 2;
            } else {
                c2 = utftext.charCodeAt(i + 1);
                c3 = utftext.charCodeAt(i + 2);
                string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                i += 3;
            }
        }
        return string;
    }
}

 <button  class="btn" onclick="cmdEncrypt()">登录</button>

function cmdEncrypt() {
            var username = $("#userName").val();
            var pwd = $("#password").val();            
            var b = new Base64();
            
            var params = {};
            params.userName64 = b.encode(username);
            params.password64 = b.encode(pwd);
            params.validcode = $("#txtCode").val();;
            params.openID = $("#openID").val();
            params.status = $("#status").val();
            //alert(params.validcode);
            $.ajax({
                type: "POST",
                async: false,
                url: "/Account/UserLogin",
                datatype: "json",
                data: params,
                error: function (msg) { alert('error')},
                success: function (msg) {
                    //alert(msg);
                    if (msg == 'success') {
                        location.href = "/Account/FirstPage?status=" + params.status;
                    }
                    else {
                        $(".tit").html(msg);                      
                    }
                }
            });
        }    

/// <summary> 
        /// Base64解密 
        /// </summary> 
        /// <param name="codeName">解密采用的编码方式，注意和加密时采用的方式一致</param> 
        /// <param name="result">待解密的密文</param> 
        /// <returns>解密后的字符串</returns> 
        public static string DecodeBase64(Encoding encode, string result)
        {
            string decode = "";
            byte[] bytes = Convert.FromBase64String(result);
            try
            {
                decode = encode.GetString(bytes);
            }
            catch
            {
                decode = result;
            }
            return decode;
        } 

 //用户名和密码解密
            string UserName = DecodeBase64(Encoding.UTF8, UserName64);
            string Pwd = DecodeBase64(Encoding.UTF8, Pwd64);