We are using the OAuthAuthorizationServerProvider class to do authorization in our ASP.NET Web Api app.

If the provided username and password is invalid in GrantResourceOwnerCredentials, the call

context.SetError( "invalid_grant", "The user name or password is incorrect." );

Produces the following Json result:

{

    "error": "invalid_grant",

    "error_description": "The user name or password is incorrect."

}

Is there any way to customize this error result?
I would like to make it consistent with default error message format used in other parts of the API:

{

    "message": "Some error occurred."

}

Is this possible to achieve with the OAuthAuthorizationServerProvider?

2016年10月12日24分24秒

This is how I did it.

string jsonString = "{\"message\": \"Some error occurred.\"}";

// This is just a work around to overcome an unknown internal bug.

// In future releases of Owin, you may remove this.

context.SetError(new string(' ',jsonString.Length-12)); 

context.Response.StatusCode = 400;

context.Response.Write(jsonString);

2016年10月11日24分24秒

+1 for Dasun's answer. Here is how I extended it a bit further.

public class ErrorMessage

{

    public ErrorMessage(string message)

    {

        Message = message;

    }

    public string Message { get; private set; }

}

public static class ContextHelper

{

    public static void SetCustomError(this OAuthGrantResourceOwnerCredentialsContext context, string errorMessage)

    {

        var json = new ErrorMessage(errorMessage).ToJsonString();

        context.SetError(json);

        context.Response.Write(json);

    }

}

The .ToJsonString() is another extension method that uses the Newtonsoft.Json library.

public static string ToJsonString(this object obj)

    {

        return JsonConvert.SerializeObject(obj);

    }

Usage:

context.SetCustomError("something went wrong");