/// <summary>
/// Salva su file le credenziali di accesso al canale
/// </summary>
/// <param name="playerID">Id del dispositivo</param>
/// <param name="token">Token di accesso o id del canale</param>
/// <returns></returns>
private async Task SaveNotificationCredentials(string playerID, string token)
{
try
{
StorageFolder localFolder = ApplicationData.Current.LocalFolder;
StorageFile pushNotificationFile = await localFolder.CreateFileAsync("push.notification", CreationCollisionOption.ReplaceExisting);
if (pushNotificationFile != null)
{
JObject jObject = new JObject
{
{ "token", new JValue(token) },
{ "playerid", new JValue(playerID) }
};
EncDecHelper encDecHelper = new EncDecHelper
{
Password = GetDevicePwd()
};
string encryptedContent = encDecHelper.AESEncrypt(jObject.ToString());
await FileIO.WriteTextAsync(pushNotificationFile, encryptedContent, Windows.Storage.Streams.UnicodeEncoding.Utf8);
}
}
catch (Exception ex)
{
Debug.WriteLine("Errore di scrittura del file di configurazione delle notifiche push. Exception: " + ex.Message);
}
}
/// <summary>
/// Ricostruisce le informazioni di accesso al Cloud da una precedente
/// serializzazione
/// </summary>
private void DeSerialize()
{
try
{
Account = null;
string data = File.ReadAllText(SerializationFileName, Encoding.UTF8);
EncDecHelper encDecHelper = new EncDecHelper
{
PasswordString = SerializationPassword
};
Xamarin.Auth.Account account = Xamarin.Auth.Account.Deserialize(encDecHelper.AESDecrypt(data, out bool warning));
if (warning)
{
Debug.Write(string.Format("Google Drive serialize file {0}. File seems to be corrupted. I have tried to recover the data.",
SerializationFileName));
}
if (account != null)
{
Account = new OAuthAccountWrapper(account);
RememberMe = true;
}
}
catch (FileNotFoundException)
{
// Accettabile
Debug.WriteLine(string.Format("Deserialize: file {0} not found", SerializationFileName));
}
catch (Exception Ex)
{
Debug.WriteLine("Deserialize error: " + Ex.Message);
}
}
/// <summary>
/// Restituisce il codice di backup da utilizzare in caso non sia possibile
/// generare il token temporale.
/// </summary>
/// <returns>Codice di backup per l'accesso</returns>
public string GetBackupCode()
{
RNGCryptoServiceProvider rngCsp = new RNGCryptoServiceProvider();
byte[] data = new byte[20];
rngCsp.GetBytes(data);
string hash = EncDecHelper.MD5(data);
string code = Convert.ToBase64String(System.Text.Encoding.UTF8.GetBytes(hash)).ToUpper();
for (int i = 1; i < 4; i++)
{
code = code.Insert(i * 8 + (i - 1), "-");
}
return(code);
}
/// <summary>
/// Restituisce una password che dipende dal dispositivo
/// </summary>
/// <returns>Password</returns>
private byte[] GetDevicePwd()
{
string defDeviceId = FakeDeviceId;
string pwd = SaltDevicePwd;
try
{
pwd += new DeviceInfo().GetDeviceID();
}
catch (Exception ex)
{
// API non trovate o non funzionanti
Debug.WriteLine("GetDevicePwd failed. Error: " + ex.Message);
pwd += defDeviceId + "napi";
}
return(EncDecHelper.SHA256Bytes(pwd));
}
public async Task Init(string AppId, Uri url, Func <NotificationInfo, Task <bool> > pushNotificationOpened)
{
OneSignalAppId = AppId;
OneSignalUrl = url;
try
{
StorageFolder localFolder = ApplicationData.Current.LocalFolder;
StorageFile pushNotificationFile = await localFolder.GetFileAsync("push.notification");
if (pushNotificationFile != null)
{
string content = await FileIO.ReadTextAsync(pushNotificationFile, Windows.Storage.Streams.UnicodeEncoding.Utf8);
if (content.Length > 0)
{
EncDecHelper encDecHelper = new EncDecHelper
{
Password = GetDevicePwd()
};
string decryptedContent = encDecHelper.AESDecrypt(content, out bool warning);
if (decryptedContent.Length > 0)
{
JObject json = JObject.Parse(decryptedContent);
PushNotificationToken = json.Value <string>("token");
PushNotificationDeviceID = json.Value <string>("playerid");
}
}
}
}
catch (FileNotFoundException)
{
// Il file non esiste
PushNotificationToken = "";
PushNotificationDeviceID = "";
}
catch (Exception ex)
{
PushNotificationToken = "";
PushNotificationDeviceID = "";
Debug.WriteLine("Errore durante la lettura del file di configurazione delle notifiche push. Exception: " + ex.Message);
throw;
}
}
/// <summary>
/// Serializzazione delle informazioni di accesso al Cloud su file
/// </summary>
private void Serialize()
{
if (!IsLoggedIn())
{
return;
}
try
{
string data = Account.OAuthAccount.Serialize();
EncDecHelper encDecHelper = new EncDecHelper
{
PasswordString = SerializationPassword
};
File.WriteAllText(SerializationFileName, encDecHelper.AESEncrypt(data), System.Text.Encoding.UTF8);
}
catch (Exception Ex)
{
Debug.WriteLine("Serialize error: " + Ex.Message);
}
}
public async void StartAuthentication(string clientId, string scope, string appSecret, Uri authorizeUrl, Uri redirectUrl, Uri tokenUrl, bool codeChallengeMethod)
{
string codeVerifier = "";
UriBuilder uriBuilder = new UriBuilder(authorizeUrl);
uriBuilder.Query += "?client_id=" + clientId + "&scope=" + Uri.EscapeUriString(scope) + "&response_type=code&redirect_uri=" + Uri.EscapeUriString(redirectUrl.AbsoluteUri);
// Codice opzionale di sicurezza
if (codeChallengeMethod)
{
codeVerifier = GetCodeVerifier();
string codeChallenge = Base64URLEncode(EncDecHelper.SHA256Bytes(codeVerifier));
uriBuilder.Query += "&code_challenge_method=S256&code_challenge=" + codeChallenge;
}
try
{
// Step 1: richiede il codice di autorizzazione
WebAuthenticationResult Result = await WebAuthenticationBroker.AuthenticateAsync(WebAuthenticationOptions.None,
uriBuilder.Uri,
redirectUrl);
if (Result.ResponseStatus == WebAuthenticationStatus.Success)
{
Account account = new Account();
// Estraggo il codice
string Code = "";
string QueryString = new Uri(Result.ResponseData).Query;
QueryString = QueryString.Substring(1); // Salta "?"
string[] QueryParams = QueryString.Split('&');
for (short i = 0; i < QueryParams.Length; i++)
{
if (QueryParams[i].Contains("code="))
{
Code = QueryParams[i].Substring(5);
break;
}
}
// Step 2: scambio il codice con un access token
HttpClient appClient = new HttpClient();
try
{
List <KeyValuePair <string, string> > Param = new List <KeyValuePair <string, string> >
{
new KeyValuePair <string, string>("client_id", clientId),
new KeyValuePair <string, string>("redirect_uri", Uri.EscapeUriString(redirectUrl.AbsoluteUri)),
new KeyValuePair <string, string>("code", Uri.EscapeUriString(Code)),
new KeyValuePair <string, string>("scope", scope),
new KeyValuePair <string, string>("grant_type", "authorization_code")
};
// Non è obbligatorio in certi casi (es: Google Drive API per iOS, Android e UWP)
if (appSecret != "")
{
Param.Add(new KeyValuePair <string, string>("client_secret", appSecret));
}
// Codice opzionale di verifica
if (codeChallengeMethod && codeVerifier != "")
{
Param.Add(new KeyValuePair <string, string>("code_verifier", codeVerifier));
}
FormUrlEncodedContent Content = new FormUrlEncodedContent(Param);
HttpResponseMessage Response = await appClient.PostAsync(tokenUrl, Content);
if (Response.IsSuccessStatusCode)
{
// Ottengo un JSON con l'access token, il refesh token e la scadenza.
string content = await Response.Content.ReadAsStringAsync();
JObject JsonObj = JObject.Parse(content);
if (JsonObj != null && JsonObj.ContainsKey("access_token"))
{
foreach (KeyValuePair <string, JToken> token in JsonObj)
{
account.Properties.Add(token.Key, token.Value.ToString());
}
account.Properties.Add("date_token", DateTime.Now.ToString("dd-MM-yyyy HH:mm:ss"));
// Step 3: richiedo un nuovo access token e un refresh token per aggiornare il
// token (in quando voglio accedere offline alla cartella di OneDrive)
OAuthAccountWrapper oAuthAccount = new OAuthAccountWrapper(account);
await RefreshToken(oAuthAccount, clientId, redirectUrl, appSecret, tokenUrl);
if (oAuthAccount.AccessToken.Length <= 0)
{
appClient.Dispose();
Debug.WriteLine("Authetication failed: access token not found in response");
throw new Exception("Access token not found in response");
}
appClient.Dispose();
Debug.WriteLine("Authetication succeeded!");
}
else
{
appClient.Dispose();
Debug.WriteLine("Authetication failed: malformed response");
throw new Exception("Malformed response");
}
}
else
{
appClient.Dispose();
Debug.WriteLine("Authetication failed: " + Response.StatusCode.ToString());
throw new Exception("HTTP Error: " + Response.StatusCode + "\nUnable to redeem a token");
}
AuthenticatorCompletedEventArgs AuthCompletedEventArgs = new AuthenticatorCompletedEventArgs(account);
Completed?.Invoke(this, AuthCompletedEventArgs);
}
catch (Exception Ex)
{
appClient.Dispose();
Debug.WriteLine("Authetication failed: " + Ex.Message);
throw;
}
}
else if (Result.ResponseStatus != WebAuthenticationStatus.UserCancel)
{
Debug.WriteLine("Authetication failed: " + Result.ResponseStatus.ToString());
throw new Exception("HTTP Error code: " + Result.ResponseErrorDetail + "\nError: " + Result.ResponseData);
}
else
{
Debug.WriteLine("Authetication cancelled by user");
// Passando null si avrà IsAuthenticated a false.
// Vedi https://github.com/xamarin/Xamarin.Auth/blob/master/source/Core/Xamarin.Auth.Common.LinkSource/AuthenticatorCompletedEventArgs.cs
AuthenticatorCompletedEventArgs AuthCompletedEventArgs = new AuthenticatorCompletedEventArgs(null);
Completed?.Invoke(this, AuthCompletedEventArgs);
}
}
catch (Exception Ex)
{
Debug.WriteLine("Authetication failed: " + Ex.Message);
AuthenticatorErrorEventArgs AuthCompletedEventArgs = new AuthenticatorErrorEventArgs(Ex);
Error?.Invoke(this, AuthCompletedEventArgs);
}
}
