ASP.NET Core 2.0 combining Cookies and Bearer Authorization for the same endpoint

If I understand the question correctly then I believe that there is a solution. In the following example I am using cookie AND bearer authentication in a single app. The [Authorize] attribute can be used without specifying the scheme, and the app will react dynamically, depending on the method of authorization being used.

services.AddAuthentication is called twice to register the 2 authentication schemes. The key to the solution is the call to services.AddAuthorization at the end of the code snippet, which tells ASP.NET to use BOTH schemes.

I've tested this and it seems to work well.

(Based on Microsoft docs.)

services.AddAuthentication(options =>
    {
        options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = "oidc";
    })
    .AddCookie(CookieAuthenticationDefaults.AuthenticationScheme)
    .AddOpenIdConnect("oidc", options =>
    {
        options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
        options.Authority = "https://localhost:4991";
        options.RequireHttpsMetadata = false;

        options.ClientId = "WebApp";
        options.ClientSecret = "secret";

        options.ResponseType = "code id_token";
        options.Scope.Add("api");
        options.SaveTokens = true;
    });

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
    .AddJwtBearer(options =>
    {
        options.Authority = "https://localhost:4991";
        options.RequireHttpsMetadata = false;
        // name of the API resource
        options.Audience = "api";
    });

services.AddAuthorization(options =>
{
    var defaultAuthorizationPolicyBuilder = new AuthorizationPolicyBuilder(
        CookieAuthenticationDefaults.AuthenticationScheme,
        JwtBearerDefaults.AuthenticationScheme);
    defaultAuthorizationPolicyBuilder =
        defaultAuthorizationPolicyBuilder.RequireAuthenticatedUser();
    options.DefaultPolicy = defaultAuthorizationPolicyBuilder.Build();
});

EDIT

This works for authenticated users, but simply returns a 401 (unauthorized) if a user has not yet logged in.

To ensure that unauthorized users are redirected to the login page, add the following code to the Configure method in your Startup class. Note: it's essential that the new middleware is placed after the call the app.UseAuthentication().

app.UseAuthentication();
app.Use(async (context, next) =>
{
    await next();
    var bearerAuth = context.Request.Headers["Authorization"]
        .FirstOrDefault()?.StartsWith("Bearer ") ?? false;
    if (context.Response.StatusCode == 401
        && !context.User.Identity.IsAuthenticated
        && !bearerAuth)
    {
        await context.ChallengeAsync("oidc");
    }
});

If you know a cleaner way to achieve this redirect, please post a comment!

I think you don't need to set the AuthenticationScheme to your Controller. Just use Authenticated user in ConfigureServices like this:

// requires: using Microsoft.AspNetCore.Authorization;
//           using Microsoft.AspNetCore.Mvc.Authorization;
services.AddMvc(config =>
{
    var policy = new AuthorizationPolicyBuilder()
                     .RequireAuthenticatedUser()
                     .Build();
    config.Filters.Add(new AuthorizeFilter(policy));
});

For Documentation of my sources: registerAuthorizationHandlers

For the part, whether the scheme-Key wasn't valid, you could use an interpolated string, to use the right keys:

[Authorize(AuthenticationSchemes = $"{CookieAuthenticationDefaults.AuthenticationScheme},{JwtBearerDefaults.AuthenticationScheme}")]

Edit: I did further research and came to following conclusion: It's not possible to authorize a method with two Schemes Or-Like, but you can use two public methods, to call a private method like this:

//private method
private IActionResult GetThingPrivate()
{
   //your Code here
}

//Jwt-Method
[Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)]
[HttpGet("bearer")]
public IActionResult GetByBearer()
{
   return GetThingsPrivate();
}

 //Cookie-Method
[Authorize(AuthenticationSchemes = CookieAuthenticationDefaults.AuthenticationScheme)]
[HttpGet("cookie")]
public IActionResult GetByCookie()
{
   return GetThingsPrivate();
}

After many hours of research and head-scratching, this is what worked for me in ASP.NET Core 2.2:

• Use .AddCookie() and .AddJwtBearer() to configure the schemes
• Use a custom policy scheme to forward to the correct Authentication Scheme.

You do not need to specify the scheme on each controller action and will work for both. [Authorize] is enough.

services.AddAuthentication( config =>
{
    config.DefaultScheme = "smart";
} )
.AddPolicyScheme( "smart", "Bearer or Jwt", options =>
{
    options.ForwardDefaultSelector = context =>
    {
        var bearerAuth = context.Request.Headers["Authorization"].FirstOrDefault()?.StartsWith( "Bearer " ) ?? false;
        // You could also check for the actual path here if that's your requirement:
        // eg: if (context.HttpContext.Request.Path.StartsWithSegments("/api", StringComparison.InvariantCulture))
        if ( bearerAuth )
            return JwtBearerDefaults.AuthenticationScheme;
        else
            return CookieAuthenticationDefaults.AuthenticationScheme;
    };
} )
.AddCookie( CookieAuthenticationDefaults.AuthenticationScheme, options =>
{
    options.LoginPath = new PathString( "/Account/Login" );
    options.AccessDeniedPath = new PathString( "/Account/Login" );
    options.LogoutPath = new PathString( "/Account/Logout" );
    options.Cookie.Name = "CustomerPortal.Identity";
    options.SlidingExpiration = true;
    options.ExpireTimeSpan = TimeSpan.FromDays( 1 ); //Account.Login overrides this default value
} )
.AddJwtBearer( JwtBearerDefaults.AuthenticationScheme, options =>
{
    options.RequireHttpsMetadata = false;
    options.SaveToken = true;
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuerSigningKey = true,
        IssuerSigningKey = new SymmetricSecurityKey( key ),
        ValidateIssuer = false,
        ValidateAudience = false
    };
} );

services.AddAuthorization( options =>
{
    options.DefaultPolicy = new AuthorizationPolicyBuilder( CookieAuthenticationDefaults.AuthenticationScheme, JwtBearerDefaults.AuthenticationScheme )
        .RequireAuthenticatedUser()
        .Build();
} );