private static async Task <Token> RefreshToken(ClientIdentifier clientIdentifier, Token tokenData)
{
Token resultToken = null;
HttpContent requestContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair <string, string>("client_secret", clientIdentifier.GetSecret()),
new KeyValuePair <string, string>("grant_type", "refresh_token"),
new KeyValuePair <string, string>("refresh_token", tokenData.refreshToken),
new KeyValuePair <string, string>("client_id", clientIdentifier.GetID()),
});
requestContent.Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");
try
{
HttpClient client = new HttpClient();
HttpResponseMessage response = await client.PostAsync(TokenApi, requestContent);
if (response.IsSuccessStatusCode)
{
string replyJson = await response.Content.ReadAsStringAsync();
resultToken = CreateToken(replyJson);
resultToken.refreshToken = tokenData.refreshToken;
}
}
catch (Exception) { }
return(resultToken);
}
private static async Task <Token> RequestToken(ClientIdentifier clientIdentifier)
{
// prepare listen server for receiving token data
if (!HttpListener.IsSupported || clientIdentifier == null)
{
return(null);
}
int listenPort = FindListenPort();
string authListenUri = "http://localhost:" + listenPort + "/auth_response/";
httpListener = new HttpListener();
httpListener.Prefixes.Add(authListenUri);
httpListener.Start();
// send authorization request: open in default browser
string authRequestUri = RequestAccessApi +
"?redirect_uri=" + Uri.EscapeDataString(authListenUri) +
"&prompt=consent" +
"&response_type=code" +
"&client_id=" + clientIdentifier.GetID() +
"&scope=" + Uri.EscapeDataString(AccessScopeAppSettings) +
"&access_type=offline";
Process.Start(authRequestUri);
// wait for reponse
string authorizationCode = null;
{
HttpListenerContext listenContext = null;
try
{
listenContext = await Task.Factory.FromAsync(httpListener.BeginGetContext(null, null), httpListener.EndGetContext);
}
catch (Exception) { listenContext = null; }
if (listenContext != null)
{
Uri requestUrl = listenContext.Request.Url;
ILookup <string, string> queryLookup = requestUrl.Query.TrimStart('?')
.Split(new[] { '&' }, StringSplitOptions.RemoveEmptyEntries)
.Select(k => k.Split('='))
.Where(k => k.Length == 2)
.ToLookup(a => a[0], a => Uri.UnescapeDataString(a[1]), StringComparer.OrdinalIgnoreCase);
authorizationCode = queryLookup["code"].FirstOrDefault();
string responseString = "<html><title>Google account verification</title><body>Received verification code. You may now close this window.</body></html>";
byte[] buffer = Encoding.UTF8.GetBytes(responseString);
HttpListenerResponse listenResponse = listenContext.Response;
listenResponse.ContentLength64 = buffer.Length;
listenResponse.OutputStream.Write(buffer, 0, buffer.Length);
listenResponse.OutputStream.Close();
}
}
// send token grant request: no user ui needed
Token resultToken = null;
if (!string.IsNullOrEmpty(authorizationCode))
{
HttpContent tokenGrantContent = new FormUrlEncodedContent(new[]
{
new KeyValuePair <string, string>("code", authorizationCode),
new KeyValuePair <string, string>("redirect_uri", authListenUri),
new KeyValuePair <string, string>("client_id", clientIdentifier.GetID()),
new KeyValuePair <string, string>("client_secret", clientIdentifier.GetSecret()),
new KeyValuePair <string, string>("scope", AccessScopeAppSettings),
new KeyValuePair <string, string>("grant_type", "authorization_code"),
});
tokenGrantContent.Headers.ContentType = new MediaTypeHeaderValue("application/x-www-form-urlencoded");
try
{
HttpClient client = new HttpClient();
HttpResponseMessage tokenGrantResponse = await client.PostAsync(TokenApi, tokenGrantContent);
if (tokenGrantResponse.IsSuccessStatusCode)
{
string replyJson = await tokenGrantResponse.Content.ReadAsStringAsync();
resultToken = CreateToken(replyJson);
}
}
catch (Exception) { }
}
if (httpListener != null && httpListener.IsListening)
{
httpListener.Close();
httpListener = null;
}
return(resultToken);
}
