C#根據用戶信息，生成token和cookie的方法

在前後端分離的項目裏，我們請求接口的流程一般是：

1. 用戶使用用戶名密碼登錄
2. 信息正確，接口返回token
3. 請求需要登錄驗證的接口，將token放到header裏一起請求接口

這裏介紹一下，在webapi項目裏，token是怎麼生成的

1. 項目的引用裏，右鍵：管理NuGet程序包
2. 搜索JWT，安裝即可，要注意項目的.NetFrameWork 要大於等於4.6

1. 代碼如下

public class TokenInfo
{
    public TokenInfo()
    {
        UserName = "jack.chen";
        Pwd = "jack123456";
    }
    public string UserName { get; set; }
    public string Pwd { get; set; }
}

public class TokenHelper
{
    public static string SecretKey = "This is a private key for Server";//這個服務端加密祕鑰 屬於私鑰
    private static JavaScriptSerializer myJson = new JavaScriptSerializer();
    public static string GenToken(TokenInfo M)
    {
        var payload = new Dictionary<string, dynamic>
            {
                {"UserName", M.UserName},//用於存放當前登錄人賬戶信息
                {"UserPwd", M.Pwd}//用於存放當前登錄人登錄密碼信息
            };
        IJwtAlgorithm algorithm = new HMACSHA256Algorithm();
        IJsonSerializer serializer = new JsonNetSerializer();
        IBase64UrlEncoder urlEncoder = new JwtBase64UrlEncoder();
        IJwtEncoder encoder = new JwtEncoder(algorithm, serializer, urlEncoder);
        return encoder.Encode(payload, SecretKey);
    }

    public static TokenInfo DecodeToken(string token)
    {
        try
        {
            var json = GetTokenJson(token);
            TokenInfo info = myJson.Deserialize<TokenInfo>(json);
            return info;
        }
        catch (Exception)
        {

            throw;
        }
    }

    public static string GetTokenJson(string token)
    {
        try
        {
            IJsonSerializer serializer = new JsonNetSerializer();
            IDateTimeProvider provider = new UtcDateTimeProvider();
            IJwtValidator validator = new JwtValidator(serializer, provider);
            IBase64UrlEncoder urlEncoder = new JwtBase64UrlEncoder();
            IJwtDecoder decoder = new JwtDecoder(serializer, validator, urlEncoder);
            var json = decoder.Decode(token, SecretKey, verify: true);
            return json;
        }
        catch (Exception)
        {
            throw;
        }
    }
}

使用cookie也是一樣，用戶登錄之後，用特定的方法生成cookie，返回到瀏覽器，瀏覽器每次請求接口或者訪問頁面的時候，都會帶上cookie信息，用於身份驗證
c#生成cookie的方法：

public class UserModel
{
    public string UserName { get; set; }
    public string Pwd { get; set; }
}

public class CookieHelper
{
    private static JavaScriptSerializer myJson = new JavaScriptSerializer();

    /// <summary>
    /// 設置登錄信息cookie
    /// </summary>
    /// <param name="model"></param>
    public static void SetUserCookie(UserModel model)
    {
        FormsAuthentication.SetAuthCookie(model.UserName, false);
        string userStr = myJson.Serialize(model);
        //創建ticket
        FormsAuthenticationTicket ticket = 
            new FormsAuthenticationTicket(1, model.UserName, DateTime.Now, 
            DateTime.Now + FormsAuthentication.Timeout, false, userStr);
        //加密
        var cookieValue = FormsAuthentication.Encrypt(ticket);
        var cookie = new HttpCookie(FormsAuthentication.FormsCookieName, cookieValue)
        {
            HttpOnly = true,
            Secure = FormsAuthentication.RequireSSL,
            Domain = FormsAuthentication.CookieDomain,
            Path = FormsAuthentication.FormsCookiePath
        };
        //寫入cookie
        HttpContext.Current.Response.Cookies.Remove(cookie.Name);
        HttpContext.Current.Response.Cookies.Add(cookie);
    }

    /// <summary>
    /// 獲取登錄信息的cookie
    /// </summary>
    /// <returns></returns>
    public static UserModel GetUserCookie()
    {
        var cookie = HttpContext.Current.Request.Cookies[FormsAuthentication.FormsCookieName];
        if (object.Equals(cookie, null) || string.IsNullOrEmpty(cookie.Value))
        {
            return null;
        }
        try
        {
            var ticket = FormsAuthentication.Decrypt(cookie.Value);
            if (!object.Equals(ticket, null) && !string.IsNullOrEmpty(ticket.UserData))
            {
                UserModel userData = myJson.Deserialize<UserModel>(ticket.UserData);
                return userData;
            }
        }
        catch (Exception)
        {
            
        }
        return null;
    }
}