Answers for "jwt authentication c#"

validate jwt token c#

public static Task<IPrincipal> validateToken(string token)
        {
            ClaimsPrincipal principal = getPrincipal(token);
            if (principal == null)
                return null;
            ClaimsIdentity identity = null;
            try
            {
                identity = (ClaimsIdentity)principal.Identity;
                IPrincipal Iprincipal = new ClaimsPrincipal(identity);
                return Task.FromResult(Iprincipal);
            }
            catch (NullReferenceException)
            {
                return Task.FromResult<IPrincipal>(null);
            }
        }

 private static ClaimsPrincipal getPrincipal(string token)
        {
            try
            {
                JwtSecurityTokenHandler tokenHandler = new JwtSecurityTokenHandler();
                JwtSecurityToken jwtToken = (JwtSecurityToken)tokenHandler.ReadToken(token);
                if (jwtToken == null)
                    return null;
                byte[] key = Encoding.ASCII.GetBytes(config.jwtSecret);
                TokenValidationParameters parameters = new TokenValidationParameters()
                {
                    ValidIssuer = config.jwtIssuer,
                    ValidAudience = config.jwtIssuer,
                    ValidateLifetime = true,
                    RequireExpirationTime = true,
                    ValidateIssuer = true,
                    ValidateAudience = true,
                    IssuerSigningKey = new SymmetricSecurityKey(key),
                    ClockSkew = TimeSpan.Zero
                };
                SecurityToken securityToken;
                ClaimsPrincipal principal = tokenHandler.ValidateToken(token,
                      parameters, out securityToken);
                return principal;
            }
            catch
            {
                return null;
            }
  }

c# jwt

// Startup.cs
services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
    options.SaveToken = true;
    options.RequireHttpsMetadata = false;
    options.TokenValidationParameters = new Microsoft.IdentityModel.Tokens.TokenValidationParameters()
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidAudience = "https://www.yogihosting.com",
        ValidIssuer = "https://www.yogihosting.com",
        IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("MynameisJamesBond007"))
    };
});

c# create jwt token

static void Main(string[] args)
       {
           Console.WriteLine("");

           // Define const Key this should be private secret key  stored in some safe place
           string key = "401b09eab3c013d4ca54922bb802bec8fd5318192b0a75f201d8b372742
           9090fb337591abd3e44453b954555b7a0812e1081c39b740293f765eae731f5a65ed1";

           // Create Security key  using private key above:
           // not that latest version of JWT using Microsoft namespace instead of System
           var securityKey = new Microsoft
               .IdentityModel.Tokens.SymmetricSecurityKey(Encoding.UTF8.GetBytes(key));

           // Also note that securityKey length should be >256b
           // so you have to make sure that your private key has a proper length
           //
           var credentials = new Microsoft.IdentityModel.Tokens.SigningCredentials
                             (securityKey, SecurityAlgorithms.HmacSha256Signature);

           //  Finally create a Token
           var header = new JwtHeader(credentials);

           //Some PayLoad that contain information about the  customer
           var payload = new JwtPayload
           {
               { "some ", "hello "},
               { "scope", "http://dummy.com/"},
           };

           //
           var secToken = new JwtSecurityToken(header, payload);
           var handler = new JwtSecurityTokenHandler();

           // Token to String so you can use it in your client
           var tokenString = handler.WriteToken(secToken);

           Console.WriteLine(tokenString);
           Console.WriteLine("Consume Token");


           // And finally when  you received token from client
           // you can  either validate it or try to  read
           var token = handler.ReadJwtToken(tokenString);

           Console.WriteLine(token.Payload.First().Value);

           Console.ReadLine();
       }