ASP.NET Web Api: How to pass an access token (oAuth 2.0) using URL parameter?

Question

Do you have any idea how I can use, an access_token generated by the default asp.net web api 2 OAuth 2 authorization mechanism, in the url parameters. Currently I am able to

Answer 1

Well - I agree that the header is a much better alternative - but there are of course situations where the query string is needed. The OAuth2 spec defines it as well.

Anyways - this feature is built into the Katana OAuth2 middleware:

http://leastprivilege.com/2013/10/31/retrieving-bearer-tokens-from-alternative-locations-in-katanaowin/

public class QueryStringOAuthBearerProvider : OAuthBearerAuthenticationProvider
{
    readonly string _name;

    public QueryStringOAuthBearerProvider(string name)
    {
        _name = name;
    }

    public override Task RequestToken(OAuthRequestTokenContext context)
    {
        var value = context.Request.Query.Get(_name);

        if (!string.IsNullOrEmpty(value))
        {
            context.Token = value;
        }

        return Task.FromResult<object>(null);
    }
}

And then:

var options = new JwtBearerAuthenticationOptions
{
    AllowedAudiences = new[] { audience },
    IssuerSecurityTokenProviders = new[]
        {
            new SymmetricKeyIssuerSecurityTokenProvider(
                issuer,
                signingKey)
        },
    Provider = new QueryStringOAuthBearerProvider(“access_token”)
};

Answer 2

This is a terrible idea because the token is not protected in the query string. It is encrypted in the header with SSL.

Answer 3

So, go to Global.asax and add this method:

        void Application_BeginRequest(object sender, EventArgs e)
        {
            if (ReferenceEquals(null, HttpContext.Current.Request.Headers["Authorization"]))
            {
                var token = HttpContext.Current.Request.Params["access_token"];
                if (!String.IsNullOrEmpty(token))
                {
                    HttpContext.Current.Request.Headers.Add("Authorization", "Bearer " + token);
                }
            }
        }

UPDATE: Check out @leastprivilege answer. Much better solution.