/// <summary>
/// Checks whether the access token should be refreshed, or if it can still be used.
/// </summary>
/// <param name="token">The token with the expiry date.</param>
/// <returns>Returns true if the token should be refreshed, otherwise false.</returns>
public static bool NeedsRefresh(this CloudStorageToken token)
{
if (token?.RefreshToken == null)
{
return(false);
}
if (token.ExpiryDate != null)
{
return(token.ExpiryDate < DateTime.UtcNow);
}
else
{
return(true);
}
}
/// <inheritdoc/>
public virtual async Task <CloudStorageToken> RefreshTokenAsync(CloudStorageToken token)
{
if (token == null)
{
throw new ArgumentNullException(nameof(token));
}
if (string.IsNullOrWhiteSpace(token.RefreshToken))
{
throw new ArgumentNullException(string.Format("{0}.{1}", nameof(token), nameof(CloudStorageToken.RefreshToken)));
}
try
{
// Installable apps cannot keep secrets, thus the client secret is not transmitted
string clientSecret = Config.ClientSecretHandling == ClientSecretHandling.SendEmptyParam
? string.Empty // Serializes as empty parameter
: null; // Won't be serialized
string jsonResponse = await Flurl
.Request(Config.TokenServiceEndpoint)
.PostUrlEncodedAsync(new
{
refresh_token = token.RefreshToken,
client_id = Config.ClientId,
client_secret = clientSecret,
grant_type = "refresh_token",
})
.ReceiveString();
JsonTokenExchangeResponse response = JsonConvert.DeserializeObject <JsonTokenExchangeResponse>(jsonResponse);
CloudStorageToken result = new CloudStorageToken
{
AccessToken = response.AccessToken,
RefreshToken = token.RefreshToken // keep the refresh token
};
result.SetExpiryDateBySecondsFromNow(response.ExpiresIn);
return(result);
}
catch (Exception ex)
{
if (await IsInvalidGrantException(ex))
{
throw new RefreshTokenExpiredException(ex);
}
throw ConvertToCloudStorageException(ex);
}
}
/// <summary>
/// If the OAuth2 service requires the code flow, we have to exchange the authorization
/// code with an access token, which can be used to access the API of the cloud storage
/// service.
/// </summary>
/// <param name="authorizationCode">The code form the authorization request, it can be
/// found in <see cref="AuthorizationResponse.Code"/>.
/// </param>
/// <param name="codeVerifier">The optional code verifier.</param>
/// <returns>A token object containing the access token and a refresh token.</returns>
protected virtual async Task <CloudStorageToken> ExchangeCodeForTokenAsync(
string authorizationCode, string codeVerifier)
{
if (string.IsNullOrWhiteSpace(authorizationCode))
{
throw new InvalidParameterException(nameof(authorizationCode));
}
try
{
// Installable apps cannot keep secrets, thus the client secret is not transmitted
string clientSecret = Config.ClientSecretHandling == ClientSecretHandling.SendEmptyParam
? string.Empty // Serializes as empty parameter
: null; // Won't be serialized
string jsonResponse = await Flurl
.Request(Config.TokenServiceEndpoint)
.PostUrlEncodedAsync(new
{
code = authorizationCode,
client_id = Config.ClientId,
client_secret = clientSecret,
redirect_uri = Config.RedirectUrl,
grant_type = "authorization_code",
code_verifier = codeVerifier,
})
.ReceiveString();
JsonTokenExchangeResponse response = JsonConvert.DeserializeObject <JsonTokenExchangeResponse>(jsonResponse);
CloudStorageToken result = new CloudStorageToken
{
AccessToken = response.AccessToken,
RefreshToken = response.RefreshToken
};
result.SetExpiryDateBySecondsFromNow(response.ExpiresIn);
return(result);
}
catch (Exception ex)
{
throw ConvertToCloudStorageException(ex);
}
}
/// <summary>
/// Call this method after deserialization, it decrypts all sensitive properties, so they
/// can be used by the application.
/// </summary>
/// <param name="decrypt">A delegate used to do the decryption of the encrypted textes.</param>
public void DecryptAfterDeserialization(Func <string, string> decrypt)
{
CloudStorageToken token = new CloudStorageToken
{
AccessToken = DecryptProperty(SerializeableAccessToken, decrypt),
ExpiryDate = SerializeableExpiryDate,
RefreshToken = DecryptProperty(SerializeableRefreshToken, decrypt),
};
if ((token.AccessToken == null) && (token.RefreshToken == null))
{
token = null;
}
CloudStorageId = SerializeableCloudStorageId;
Token = token;
Username = DecryptProperty(SerializeableUsername, decrypt);
UnprotectedPassword = DecryptProperty(SerializeablePassword, decrypt);
Url = SerializeableUrl;
Secure = SerializeableSecure;
}