Authentication That Doesn't Require Javascript? - rest

Question

I have a Web API app, initialized thusly:
app.UseCookieAuthentication();
app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);
app.UseOAuthBearerTokens(OAuthOptions);
app.UseGoogleAuthentication();
For calls to most controllers, it works great. However, it also requires a bit of javascript before client-side service calls are made:
function getSecurityHeaders() {
var accessToken = sessionStorage["accessToken"] || localStorage["accessToken"];
if (accessToken) {
return { "Authorization": "Bearer " + accessToken };
}
return {};
}
The problem is that we have a certain type of controller (one that accesses files) where no javascript can be run during the call. For example, the call might be to:
http://mysite/mycontroller/file/filename.jpg
...where the value is assigned as the src attribute of an img tag. The call works, but Thread.CurrentPrincipal.Identity is unauthenticated with a null name, so there's currently not a way to enforce security.
I'm new to Web API, so it may be a dumb question, but what's the way around this? What switches do I need to flip to not require javascript to add security headers? I was considering trying to find a way to force an authorization header in an IAuthorizationFilter or something, but I'm not even sure that would work.

Answer 1

So I figured out the solution to my problem.
First, I needed to configure the app to use an authentication type of external cookies thusly:
//the line below is the one I needed to change
app.UseCookieAuthentication(AuthenticationType = DefaultAuthenticationTypes.ExternalCookie);
app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);
app.UseOAuthBearerTokens(OAuthOptions);
app.UseGoogleAuthentication();
Second, it turned out there was a line of code in my WebApiConfig file that was disabling reading the external cookie:
//this line needed to be removed
//config.SuppressDefaultHostAuthentication();
After that, I could see the external cookie from Google, which passed along an email address I could identify the user with.