如何从JWT令牌.NET 4.5中读取声明

Question

I can't read token claims from Bearer JWT token. Login is working, the http request comes with a valid jwt token to the backend. The application is self hosted on IIS7. Here is my code on server side:

SecurityConfig.cs

app.UseOAuthAuthorizationServer(new OAuthAuthorizationServerOptions
{
    TokenEndpointPath = new PathString("/token"),
    AccessTokenExpireTimeSpan = TimeSpan.FromHours(24),
    Provider = new AuthorizationServerProvider() ,
    AccessTokenFormat = new JwtFormat(TimeSpan.FromHours(24))
});

app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());

AuthorizationServerProvider.cs

ClaimsIdentity id = new ClaimsIdentity(context.Options.AuthenticationType);

id.AddClaim(new Claim(InosysClaimTypes.UserId, Convert.ToString(appContext.UserId)));

id.AddClaim(new Claim(InosysClaimTypes.Username, context.UserName));
id.AddClaim(new Claim(InosysClaimTypes.Password, context.Password));

id.AddClaim(new Claim(InosysClaimTypes.FirNr, Convert.ToString(appContext.FirmenNummer)));
id.AddClaim(new Claim(InosysClaimTypes.FirNdl, Convert.ToString(appContext.Niederlassung)));
id.AddClaim(new Claim(InosysClaimTypes.Bereich, Convert.ToString(appContext.Bereich)));

id.AddClaim(new Claim(InosysClaimTypes.Sprache, Convert.ToString(appContext.Sprache)));
id.AddClaim(new Claim(InosysClaimTypes.SchiffNummern, appContext.SchiffNummern == null ? "" : string.Join(",", appContext.SchiffNummern)));
id.AddClaim(new Claim(InosysClaimTypes.Geschaeftsjahr, Convert.ToString(appContext.Geschaeftsjahr)));

var principal = new ClaimsPrincipal(id);
Thread.CurrentPrincipal = principal;
if (HttpContext.Current != null)
{
    HttpContext.Current.User = principal;
}

context.Validated(id);

In the ApiController i try to get the caller's payload information like this:

ClaimsIdentity identity = User.Identity as ClaimsIdentity;

if (identity != null)
{
    appContext.UserId = Convert.ToInt32(identity.FindFirst(InosysClaimTypes.UserId).Value);
    appContext.Username = identity.FindFirst(InosysClaimTypes.Username).Value;
}

That is the identity variable debugged: identity

Answer 1

I don't know what is going wrong with your AuthorizationServerProvider.cs , But from the moment you provide a jwt token in your request header i think it will work this way.

I process the Header with an AuthorizeAttribute on each Controller accepting JWT authorization to set the Current Principal for the request.

public class JwtAuthentication : AuthorizeAttribute
{
    protected override bool IsAuthorized(HttpActionContext actionContext)
    {
        var authHeader=actionContext.Request.Headers.Authorization;
        if (authHeader!=null&& !String.IsNullOrWhiteSpace(authHeader.Parameter))
            System.Threading.Thread.CurrentPrincipal = JwtAuthenticationHandler.GetPrincipal(authHeader.Parameter);
        return ClientAuthorize.Authorize(Roles);
    }
}

Usage

[JwtAuthentication(Roles = "User")]
public class ChatBotController : ApiController
{}

Note i have been experiencing some issues with visual studio 2017 reading the Current Principal from the Thread. You might have a look at if you still experience issues. ClaimsPrincipal.Current Visual Studio 2017 different behavior

Answer 2

All I needed to do was to implement the unprotect function in the JWTFormat class

public AuthenticationTicket Unprotect(string protectedText)
{           
      try
      {
          var handler = new JwtSecurityTokenHandler();

          AppContext = new AppContext(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString)
                    {
                        EventLogPriority = Properties.Settings.Default.EventLogPriority
                    };

          SecurityToken validToken;

          _validationParameters.IssuerSigningKey = new SymmetricSecurityKey(TextEncodings.Base64Url.Decode(Secret));
                    ClaimsPrincipal principal = handler.ValidateToken(protectedText, _validationParameters, out validToken);

           var validJwt = validToken as JwtSecurityToken;

           if (validJwt == null)
           {
               throw new ArgumentException("Invalid JWT");
           }

           ClaimsIdentity identity = principal.Identities.FirstOrDefault();
           return new AuthenticationTicket(identity, new AuthenticationProperties());
     }            
     catch (SecurityTokenException ex)
     {
          var msg = new HttpResponseMessage(HttpStatusCode.Unauthorized) { ReasonPhrase = "Access Token is manipulated" };
                    throw new HttpResponseException(msg);
     }
}