protected void Page_Load(object sender, EventArgs e)
{
GoogleAuthorizationCodeFlow flow;
var assembly = Assembly.GetExecutingAssembly();
using (var stream = assembly.GetManifestResourceStream("Tasks.ASP.NET.SimpleOAuth2.client_secrets.json"))
{
flow = new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
{
DataStore = new FileDataStore("Tasks.ASP.NET.Sample.Store"),
ClientSecretsStream = stream,
Scopes = new[] { TasksService.Scope.TasksReadonly }
});
}
var uri = Request.Url.ToString();
var code = Request["code"];
if (code != null)
{
var token = flow.ExchangeCodeForTokenAsync(UserId, code,
uri.Substring(0, uri.IndexOf("?")), CancellationToken.None).Result;
// Extract the right state.
var oauthState = AuthWebUtility.ExtracRedirectFromState(
flow.DataStore, UserId, Request["state"]).Result;
Response.Redirect(oauthState);
}
else
{
var result = new AuthorizationCodeWebApp(flow, uri, uri).AuthorizeAsync(UserId,
CancellationToken.None).Result;
if (result.RedirectUri != null)
{
// Redirect the user to the authorization server.
Response.Redirect(result.RedirectUri);
}
else
{
// The data store contains the user credential, so the user has been already authenticated.
service = new TasksService(new BaseClientService.Initializer
{
ApplicationName = "Tasks API Sample",
HttpClientInitializer = result.Credential
});
}
}
}
/// <summary>
/// Processes the request based on the path.
/// </summary>
/// <param name="context">Contains the request and response.</param>
public void ProcessRequest(HttpContext context)
{
// Redirect base path to signin.
if (context.Request.Path.EndsWith("/"))
{
context.Response.RedirectPermanent("signin.ashx");
}
// This is reached when the root document is passed. Return HTML
// using index.html as a template.
if (context.Request.Path.EndsWith("/signin.ashx"))
{
String state = (String)context.Session["state"];
// Store a random string in the session for verifying
// the responses in our OAuth2 flow.
if (state == null)
{
Random random = new Random((int)DateTime.Now.Ticks);
StringBuilder builder = new StringBuilder();
for (int i = 0; i < 13; i++)
{
builder.Append(Convert.ToChar(
Convert.ToInt32(Math.Floor(
26 * random.NextDouble() + 65))));
}
state = builder.ToString();
context.Session["state"] = state;
}
// Render the templated HTML.
String templatedHTML = File.ReadAllText(
context.Server.MapPath("index.html"));
templatedHTML = Regex.Replace(templatedHTML,
"[{]{2}\\s*APPLICATION_NAME\\s*[}]{2}", APP_NAME);
templatedHTML = Regex.Replace(templatedHTML,
"[{]{2}\\s*CLIENT_ID\\s*[}]{2}", secrets.ClientId);
templatedHTML = Regex.Replace(templatedHTML,
"[{]{2}\\s*STATE\\s*[}]{2}", state);
context.Response.ContentType = "text/html";
context.Response.Write(templatedHTML);
return;
}
if (context.Session["authState"] == null)
{
// The connect action exchanges a code from the sign-in button,
// verifies it, and creates OAuth2 credentials.
if (context.Request.Path.Contains("/connect"))
{
// Get the code from the request POST body.
StreamReader sr = new StreamReader(
context.Request.InputStream);
string code = sr.ReadToEnd();
string state = context.Request["state"];
// Test that the request state matches the session state.
if (!state.Equals(context.Session["state"]))
{
context.Response.StatusCode = 401;
return;
}
// Use the code exchange flow to get an access and refresh token.
IAuthorizationCodeFlow flow =
new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
{
ClientSecrets = secrets,
Scopes = SCOPES
});
token = flow.ExchangeCodeForTokenAsync("", code, "postmessage",
CancellationToken.None).Result;
// Create an authorization state from the returned token.
context.Session["authState"] = token;
// Get tokeninfo for the access token if you want to verify.
Oauth2Service service = new Oauth2Service(
new Google.Apis.Services.BaseClientService.Initializer());
Oauth2Service.TokeninfoRequest request = service.Tokeninfo();
request.AccessToken = token.AccessToken;
Tokeninfo info = request.Execute();
string gplus_id = info.UserId;
}
else
{
// No cached state and we are not connecting.
context.Response.StatusCode = 400;
return;
}
}
else if (context.Request.Path.Contains("/connect"))
{
// The user is already connected and credentials are cached.
context.Response.ContentType = "application/json";
context.Response.StatusCode = 200;
context.Response.Write(JsonConvert.SerializeObject("Current user is already connected."));
return;
}
else
{
// Register the authenticator and construct the Plus service
// for performing API calls on behalf of the user.
token = (TokenResponse)context.Session["authState"];
IAuthorizationCodeFlow flow =
new GoogleAuthorizationCodeFlow(new GoogleAuthorizationCodeFlow.Initializer
{
ClientSecrets = secrets,
Scopes = SCOPES
});
UserCredential credential = new UserCredential(flow, "me", token);
bool success = credential.RefreshTokenAsync(CancellationToken.None).Result;
token = credential.Token;
ps = new PlusService(
new Google.Apis.Services.BaseClientService.Initializer()
{
ApplicationName = ".NET Quickstart",
HttpClientInitializer = credential
});
}
// Perform an authenticated API request to retrieve the list of
// people that the user has made visible to the app.
if (context.Request.Path.Contains("/people"))
{
// Get the PeopleFeed for the currently authenticated user.
PeopleFeed pf = ps.People.List("me",
PeopleResource.ListRequest.CollectionEnum.Visible).Execute();
// This JSON, representing the people feed, will later be
// parsed by the JavaScript client.
string jsonContent =
Newtonsoft.Json.JsonConvert.SerializeObject(pf);
context.Response.ContentType = "application/json";
context.Response.Write(jsonContent);
return;
}
// Disconnect the user from the application by revoking the tokens
// and removing all locally stored data associated with the user.
if (context.Request.Path.Contains("/disconnect"))
{
// Perform a get request to the token endpoint to revoke the
// refresh token.
token = (TokenResponse)context.Session["authState"];
string tokenToRevoke = (token.RefreshToken != null) ?
token.RefreshToken : token.AccessToken;
WebRequest request = WebRequest.Create(
"https://accounts.google.com/o/oauth2/revoke?token=" +
tokenToRevoke);
WebResponse response = request.GetResponse();
// Remove the cached credentials.
context.Session["authState"] = null;
// You could reset the state in the session but you must also
// reset the state on the client.
// context.Session["state"] = null;
context.Response.Write(
response.GetResponseStream().ToString().ToCharArray());
return;
}
}
