Asp.net core web api using windows authentication - Cors request unauthorised

问题

In my asp.net core web api, I've configured Cors as per the article from MS documentation. The web api app is using windows authentication (Anonymous Authentication is Not enabled). Cor's policy is created and middle ware is added as below in the startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddCors(options =>
    {
        options.AddPolicy("CorsPolicy",
            builder => builder.WithOrigins("http://localhost:4200")
                .AllowAnyMethod()
                .AllowAnyHeader()
                .AllowCredentials()
            );
    });

    services.AddMvc().AddJsonOptions(options => {
        options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
    });
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{         
    //Enable CORS policy 
    app.UseCors("CorsPolicy");
    app.UseMvc();
}

Also applied the policy per controller level

[EnableCors("CorsPolicy"), Route("api/[controller]")]
public class LocationController : BaseController<Location>
{
  //code
}

Options request is getting Unauthorized. The request & response looks like

I have seen similar questions and tried almost every solution but the options request is still failing.

回答1:

You may want to read this thread: https://github.com/aspnet/CORS/issues/60. You can mix anonymous and NTLM so that your CORS preflights aren't denied (since they don't include windows credentials). IIS handles NTLM authentication before it even gets to the middleware so this is probably an IIS thing. You may need to allow anonymous CORs preflight checks.

回答2:

This is very similar to CORS enabled but response for preflight has invalid HTTP status code 404 when POSTing JSON and provided solution working for me(I had 401 error on POST requests). Also NTLM and Negotiate should not be configured both(Negotiate V/s NTLM).

回答3:

It looks like you want pass credential or along with request.

Please Check this link for add credential / allow user credential.

Be careful when allowing cross-origin credentials. A website at another domain can send a logged-in user's credentials to the app on the user's behalf without the user's knowledge. The CORS specification also states that setting origins to "*" (all origins) is invalid if the Access-Control-Allow-Credentials header is present.

回答4:

Using IIS CORS Module solved the problem superbly. Below URL is for reference.

Working with Windows Authentication While this is by no means the only scenario solved by the CORS module, it was important enough to warrant calling out. Previously, if you tried to make a cross-domain request to an application that used Windows Authentication, your preflight request would fail since the browser did not send credentials with the preflight request. There was no way to work around this without enabling anonymous authentication in your application. Since the CORS module kicks in before authentication, it makes it possible to handle a pre-flight request without compromising on the security model of your application. Here's an example of what your web.config might look like.

https://blogs.iis.net/iisteam/getting-started-with-the-iis-cors-module

Sample Code:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <!-- To customize the asp.net core module uncomment and edit the following section. 
         For more info see https://go.microsoft.com/fwlink/?linkid=838655 -->
         <system.web>
        <authentication mode="Windows"/>
    </system.web>
  <system.webServer>
  <cors enabled="true" failUnlistedOrigins="true">
            <add origin="http://localhost:60096" allowCredentials="true" >
            <allowHeaders allowAllRequestedHeaders="true">
                    <add header="Header1" />
                </allowHeaders>
            </add>
        </cors>
    <handlers>
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
    </handlers>
    <aspNetCore processPath="dotnet" arguments=".\Project.Api.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" />
  </system.webServer>
</configuration>

来源：https://stackoverflow.com/questions/50130623/asp-net-core-web-api-using-windows-authentication-cors-request-unauthorised