protected async Task <string> PostAuthenticate(HttpResponseMessage response)
{
// An HTTP 401 Not Authorized error; handle if an authentication callback has been supplied
if (OnAuthenticate != null)
{
// Extract the WWW-Authenticate header and determine if it represents an OAuth2 Bearer challenge
var authenticateHeader = response.Headers.WwwAuthenticate.ElementAt(0).ToString();
if (HttpBearerChallenge.IsBearerChallenge(authenticateHeader))
{
var challenge = new HttpBearerChallenge(response.RequestMessage.RequestUri, authenticateHeader);
if (challenge != null)
{
// Update challenge cache
HttpBearerChallengeCache.GetInstance().SetChallengeForURL(response.RequestMessage.RequestUri, challenge);
// We have an authentication challenge, use it to get a new authorization token
return(await OnAuthenticate(challenge.AuthorizationServer, challenge.Resource, challenge.Scope).ConfigureAwait(false));
}
}
}
return(null);
}
async Task <string> PreAuthenticate(Uri url)
{
if (OnAuthenticate != null)
{
var challenge = HttpBearerChallengeCache.GetInstance().GetChallengeForURL(url);
if (challenge != null)
{
return(await OnAuthenticate(challenge.AuthorizationServer, challenge.Resource, challenge.Scope).ConfigureAwait(false));
}
else
{
return(await OnAuthenticate(null, null, null).ConfigureAwait(false));
}
}
return(null);
}