Simple Authentication using Jwt in dot net core MVC - model-view-controller

Question

I'm trying to add JWT validation in my dot net core application. I've followed this link to understand JWT and able to generate a token by givings some values like this.
var token = new JwtSecurityToken(
issuer: issuer,
audience: aud,
claims: claims,
expires: expTime,
signingCredentials: creds
);
Edit: and to follow this answer, I've also added JwtBearerAuthentication middleware in my app by adding app.UseJwtBearerAuthentication(new JwtBearerOptions { /* options */ }) to Startup.Configure() method.
Now I'm stuck how could I pass this token inside HTTP header? I'm generating this token on Login but whats next? How could I get to know that JWT is added and working fine??
Any kind of help will be appreciated.

Answer 1

This is a runnable sample for bearer token authentication in ASP.NET Core.
How to achieve a bearer token authentication and authorization in ASP.NET Core
At back end, you can generate the token following this code:
[Route("api/[controller]")]
public class TokenAuthController : Controller
{
[HttpPost]
public string GetAuthToken(User user)
{
var existUser = UserStorage.Users.FirstOrDefault(u => u.Username == user.Username && u.Password == user.Password);
if (existUser != null)
{
var requestAt = DateTime.Now;
var expiresIn = requestAt + TokenAuthOption.ExpiresSpan;
var token = GenerateToken(existUser, expiresIn);
return JsonConvert.SerializeObject(new {
stateCode = 1,
requertAt = requestAt,
expiresIn = TokenAuthOption.ExpiresSpan.TotalSeconds,
accessToken = token
});
}
else
{
return JsonConvert.SerializeObject(new { stateCode = -1, errors = "Username or password is invalid" });
}
}
private string GenerateToken(User user, DateTime expires)
{
var handler = new JwtSecurityTokenHandler();
ClaimsIdentity identity = new ClaimsIdentity(
new GenericIdentity(user.Username, "TokenAuth"),
new[] {
new Claim("ID", user.ID.ToString())
}
);
var securityToken = handler.CreateToken(new SecurityTokenDescriptor
{
Issuer = TokenAuthOption.Issuer,
Audience = TokenAuthOption.Audience,
SigningCredentials = TokenAuthOption.SigningCredentials,
Subject = identity,
Expires = expires
});
return handler.WriteToken(securityToken);
}
}
In Startup.cs/ConfigureServices method
services.AddAuthorization(auth =>
{
auth.AddPolicy("Bearer", new AuthorizationPolicyBuilder()
.AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme‌​)
.RequireAuthenticatedUser().Build());
});
And add this code in Configure method
app.UseJwtBearerAuthentication(new JwtBearerOptions {
TokenValidationParameters = new TokenValidationParameters {
IssuerSigningKey = TokenAuthOption.Key,
ValidAudience = TokenAuthOption.Audience,
ValidIssuer = TokenAuthOption.Issuer,
ValidateIssuerSigningKey = true,
ValidateLifetime = true,
ClockSkew = TimeSpan.FromMinutes(0)
}
});
At front end, you just add the token to header like this:
$.ajaxSetup({
headers: { "Authorization": "Bearer " + accessToken }
});
or
$.ajax("http://somedomain/somepath/somepage",{
headers:{ "Authorization": "Bearer " + accessToken },
/*some else parameter for ajax, see more you can review the Jquery API*/
});