/// <summary>
/// Queries the access token from the specified authorization code.
/// </summary>
/// <param name="returnUrl">The return URL.</param>
/// <param name="authorizationCode">The authorization code.</param>
/// <returns>
/// The access token
/// </returns>
protected override string QueryAccessToken(Uri returnUrl, string authorizationCode)
{
string formData = UriUtility.CreateQueryString(
new UriParameter("client_id", _appId),
new UriParameter("client_secret", _appSecret),
new UriParameter("code", authorizationCode),
new UriParameter("grant_type", "authorization_code"),
new UriParameter("redirect_uri", returnUrl.GetLeftPart(UriPartial.Path))); // Google OAuth 2 doesn't like query parameters.
var request = WebRequest.Create(TokenEndpoint);
request.ContentType = "application/x-www-form-urlencoded";
request.ContentLength = formData.Length;
request.Method = "POST";
using (var stream = request.GetRequestStream())
{
var writer = new StreamWriter(stream);
writer.Write(formData);
writer.Flush();
}
var response = (HttpWebResponse)request.GetResponse();
if (response.StatusCode == HttpStatusCode.OK)
{
using (var stream = response.GetResponseStream())
{
var data = OAuthHelpers.Deserialize <OAuth2AccessTokenData>(stream);
if (data != null)
{
return(data.AccessToken);
}
}
}
return(null);
}