How do you set katana-project to allow token requests in json format?

Question

When I setup an OAuth Authorization Server in asp.net webapi 2 how can I set the token endpoint to accept json rather then a form encoded post? Using the sample http://www.asp.net/web-api/overview/security/individual-accounts-in-web-api I tried to send application/json with ``` { "grant_type":"password", "username":"Alice", "password":"password123" } ``` I receive the response 400 Bad Request ``` { "error" : "unsupported_grant_type" } ``` where as a content type of application/x-www-form-urlencoded and body of `grant_type=password&username=Alice&password=password123` works as expected. 200 OK ``` { "access_token" : "08cQ33ZG728AqBcj1PBsRSs4iBPc02lLCZfpaRRWLx2mH_wpQzMwGDKS7r7VgJiKUjUFaq6Xv0uguINoiB_evVbVOtvyWaqAYvc0HRjlgrbj12uQqFbUB7bgH-jiyfhumkwuTSTVHfKUhBjCuD_pbyxEbu2K5WSJpUVge_SGxnb-htm4ZNf1qKDmpEnP9IpZVeJa-KnV0m0gEmP04slMW_JrO390LzCNvXZwVk1yMNuvDakk8tWX7Y6WkFoh7vtW6xfhw3QMbmnvS6px70yMWcTksRNG2bdmi4SenhuRTJx8IsCMnz-4Co7KiCNJGF7KLeU4WzE-LSqXv3mQ30CIQ7faXoMn53p83wZ1NoXYyhsNrQD4POUns_I…

Accepted Answer

Based on the current implementation of `OAuthAuthorizationServerHandler` you cannot.

```
private async Task InvokeTokenEndpointAsync()
{
     DateTimeOffset currentUtc = Options.SystemClock.UtcNow;
     // remove milliseconds in case they don't round-trip
     currentUtc = currentUtc.Subtract(TimeSpan.FromMilliseconds(currentUtc.Millisecond));

IFormCollection form = await Request.ReadFormAsync();
     var clientContext = new OAuthValidateClientAuthenticationContext(
                Context,
                Options,
                form);

await Options.Provider.ValidateClientAuthentication(clientContext);

if (!clientContext.IsValidated)
     {
          _logger.WriteError("clientID is not valid.");
          if (!clientContext.HasError)
          {
               clientContext.SetError(Constants.Errors.InvalidClient);
          }
          await SendErrorAsJsonAsync(clientContext);
          return;
      }

var tokenEndpointRequest = new TokenEndpointRequest(form);
}
```

So in order to attempt this you will need to provide your own implementation of `OAuthAuthorizationServerMiddleware` that overloads `CreateHandler` so you can provide your own implementation of `AuthenticationHandler<OAuthAuthorizationServerOptions>`

How do you set katana-project to allow token requests in json format?

Solution

Problem