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);
}
/// <summary>
/// Gets the challenge for the cached URL.
/// </summary>
/// <param name="url"> the URL that the challenge is cached for.</param>
/// <returns>the cached challenge or null otherwise.</returns>
public HttpBearerChallenge GetChallengeForURL(Uri url)
{
if (url == null)
{
throw new ArgumentNullException("url");
}
HttpBearerChallenge value = null;
lock (cacheLock)
{
cache.TryGetValue(url.FullAuthority(), out value);
}
return(value);
}
/// <summary>
/// Caches the challenge for the specified URL
/// </summary>
/// <param name="url"> URL corresponding to challenge as cache key </param>
/// <param name="value"> the challenge </param>
public void SetChallengeForURL(Uri url, HttpBearerChallenge value)
{
if (url == null)
{
throw new ArgumentNullException("url");
}
if (value == null)
{
throw new ArgumentNullException("value");
}
if (string.Compare(url.FullAuthority(), value.SourceAuthority, StringComparison.OrdinalIgnoreCase) != 0)
{
throw new ArgumentException("Source URL and Challenge URL do not match");
}
lock (cacheLock)
{
cache[url.FullAuthority()] = value;
}
}