.Net Core JWT Authentication Part 1

Step 1: Create .net core auth project

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    
  </ItemGroup>


</Project>

Step 2: Add Microsoft.AspNetCore.Authentication.JwtBearer and mongodb package

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="3.1.5" />
    <PackageReference Include="MongoDB.Driver" Version="2.10.4" />
  </ItemGroup>


</Project>

Step 3: Create Model UserDetails

namespace FST.EasyCart.Auth.Model
{
    
    public class UserDetails
    {
        public int UserId { get; set; }
        public string UserName { get; set; }
        public UserRole UserRole { get; set; }
        public string Password { get; set; }
    }
}

Step 4: Create Model Auth

namespace FST.EasyCart.Auth.Model
{
    public enum UserRole
    {
        User,
        Admin
    }
}

Step 5: Create IMongoDbData interface

namespace FST.EasyCart.Auth.Data
{
    public interface IMongoDbData
    {
        Task<UserDetails> GetUserDetails(string userName, string password);
        Task SaveUserDetails(UserDetails userDetails);
    }
}

Step 6: Create MongoDbData class

namespace FST.EasyCart.Auth.Data
{
    public class MongoDbData : IMongoDbData
    {
        private readonly IMongoClient _mongoClient;
        private readonly IMongoCollection<UserDetails> _userDetailsCol;
        public MongoDbData(IMongoClient mongoClient)
        {
            BsonClassMap.RegisterClassMap<UserDetails>(c =>
            {
                c.AutoMap();
                c.SetIgnoreExtraElements(true);
            });

            _mongoClient = mongoClient;
            var mongoDb = _mongoClient.GetDatabase("Order");
            _userDetailsCol = mongoDb.GetCollection<UserDetails>("UserDetails");

        }
        public async Task<UserDetails> GetUserDetails(string userName, string password)
        {

            var userDetails = await _userDetailsCol.FindAsync(f => f.UserName == userName &amp;&amp; f.Password == password).ConfigureAwait(false);
            while (await userDetails.MoveNextAsync()) {
                if (userDetails.Current.Any()) {
                    return userDetails.Current.FirstOrDefault();
                }
            }
            return null;
        }

        public Task SaveUserDetails(UserDetails userDetails)
        {
            return _userDetailsCol.InsertOneAsync(userDetails);
        }
    }
}

Step 7: Add Singleton service in Startup

public void ConfigureServices(IServiceCollection services)
        {
            var mongoCon = Configuration.GetSection("MongoDb")["MongoUrl"];
            services.AddSingleton<IMongoClient>(new MongoClient(mongoCon));
            services.AddSingleton<IMongoDbData, MongoDbData>();
            services.AddControllers();
        }

Step 8: Add mongo url in appsettings.json

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "MongoDb": {
    "MongoUrl": "mongodb://localhost:27017"
  }
}

Step 9: Create private and public certificate

openssl genrsa 2048 > private.key
openssl req -new -x509 -nodes -sha1 -days 1000 -key private.key > public.cer
openssl pkcs12 -export -in public.cer -inkey private.key -out cert_key.p12

Step 10: Create AuthController and add get,save and generate token method

namespace FST.EasyCart.Auth.Controllers
{
    [ApiController]
    [Route("api/[controller]")]
    public class AuthController : ControllerBase
    {
        private readonly ILogger<AuthController> _logger;
        private readonly IMongoDbData _mongoDbData;

        public AuthController(ILogger<AuthController> logger, IMongoDbData mongoDbData)
        {
            _logger = logger;
            _mongoDbData = mongoDbData;
        }

        [HttpGet]
        [Route("token")]
        public async Task<IActionResult> Get()
        {
            var authBasicToken = HttpContext.Request.Headers["Authorization"].ToString();
            if (!authBasicToken.StartsWith("Basic"))
            {
                return BadRequest();
            }
            var decodedAuthToken = Encoding.UTF8.GetString(Convert.FromBase64String(authBasicToken.Substring(6).Trim()));
            var userNamePassword = decodedAuthToken.Split(":");
            var userDetails = await _mongoDbData.GetUserDetails(userNamePassword[0], userNamePassword[1]).ConfigureAwait(false);
            if(userDetails!=null)
            //if (userNamePassword[0] == "admin" &amp;&amp; userNamePassword[1] == "pass")
            {
                //var getClaimsData = repo.getdata(username);
                var token = GenerateToken(userNamePassword[0]);
                return Ok(token);
            }
            return BadRequest();
      }

        [HttpPost]
        [Route("user")]
        public async Task<IActionResult> Post(UserDetails userDetails)
        {
            try
            {
                await _mongoDbData.SaveUserDetails(userDetails).ConfigureAwait(false);
                return Ok();
            }
            catch (Exception ex)
            {

                return BadRequest();
            }
        }

            private string GenerateToken(string userName)
        {
            X509Certificate2 x509Certificate2 = new X509Certificate2(@"C:\Projects\Keys\cert_key.p12", "test");
            //X509Certificate2 x509Certificate2 = GetCertificateFromStore();
            X509SecurityKey x509SecurityKey = new X509SecurityKey(x509Certificate2);

            var secToken = new JwtSecurityToken(
                "www.errorandsolution.com",
                "www.errorandsolution.com",
                claims: new[] { new Claim(ClaimTypes.Name,userName) },
                expires:DateTime.Now.AddMinutes(20),
                signingCredentials:new SigningCredentials(x509SecurityKey,SecurityAlgorithms.RsaSha256Signature)
                );
            JwtSecurityTokenHandler jwtSecurityTokenHandler = new JwtSecurityTokenHandler();

            return jwtSecurityTokenHandler.WriteToken(secToken);
        }

        private X509Certificate2 GetCertificateFromStore()
        {
            X509Store store = new X509Store(StoreLocation.CurrentUser);

            try
            {
                store.Open(OpenFlags.ReadOnly);
                X509Certificate2Collection certificate2Collection = store.Certificates;
                X509Certificate2Collection currentCert = certificate2Collection.Find(X509FindType.FindByTimeValid, DateTime.Now, false);
                X509Certificate2Collection signCert = currentCert.Find(X509FindType.FindBySubjectDistinguishedName, "CN=www.errorandsolution.com, OU=Tech, O=FreeShareTechnology, L=Free, S=IT, C=US", false);

                if (signCert.Count == 0) {
                    return null;
                }
                return signCert[0];
            }
            catch (Exception)
            {

                throw;
            }
        }
    }
}

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