public static Authenticator FromOtpAuthUri(string uri)
{
var uriMatch = Regex.Match(Uri.UnescapeDataString(uri), @"^otpauth:\/\/([a-z]+)\/(.*)\?(.*)$");
if (!uriMatch.Success)
{
throw new ArgumentException("URI is not valid");
}
var type = uriMatch.Groups[1].Value switch {
"totp" => AuthenticatorType.Totp,
"hotp" => AuthenticatorType.Hotp,
_ => throw new ArgumentException("Unknown type")
};
// Get the issuer and username if possible
var issuerUsername = uriMatch.Groups[2].Value;
var issuerUsernameMatch = Regex.Match(issuerUsername, @"^(.*):(.*)$");
var queryString = uriMatch.Groups[3].Value;
var args = Regex.Matches(queryString, "([^?=&]+)(=([^&]*))?")
.ToDictionary(x => x.Groups[1].Value, x => x.Groups[3].Value);
string issuer;
string username;
if (issuerUsernameMatch.Success)
{
issuer = issuerUsernameMatch.Groups[1].Value;
username = issuerUsernameMatch.Groups[2].Value;
}
else
{
if (args.ContainsKey("issuer"))
{
issuer = args["issuer"];
username = issuerUsername;
}
else
{
issuer = uriMatch.Groups[2].Value;
username = null;
}
}
var algorithm = DefaultAlgorithm;
if (args.ContainsKey("algorithm"))
{
algorithm = args["algorithm"].ToUpper() switch
{
"SHA1" => OtpHashMode.Sha1,
"SHA256" => OtpHashMode.Sha256,
"SHA512" => OtpHashMode.Sha512,
_ => throw new ArgumentException("Unknown algorithm")
}
}
;
var digits = DefaultDigits;
if (args.ContainsKey("digits") && !Int32.TryParse(args["digits"], out digits))
{
throw new ArgumentException("Digits parameter cannot be parsed.");
}
var period = DefaultPeriod;
if (args.ContainsKey("period") && !Int32.TryParse(args["period"], out period))
{
throw new ArgumentException("Period parameter cannot be parsed.");
}
var counter = 0;
if (type == AuthenticatorType.Hotp && args.ContainsKey("counter") && !Int32.TryParse(args["counter"], out counter))
{
throw new ArgumentException("Counter parameter cannot be parsed.");
}
if (counter < 0)
{
throw new ArgumentException("Counter cannot be negative.");
}
if (!args.ContainsKey("secret"))
{
throw new ArgumentException("Secret parameter is required.");
}
var secret = CleanSecret(args["secret"], type);
var auth = new Authenticator {
Secret = secret,
Issuer = issuer.Trim().Truncate(IssuerMaxLength),
Username = username?.Trim().Truncate(UsernameMaxLength),
Icon = Shared.Data.Icon.FindServiceKeyByName(issuer),
Type = type,
Algorithm = algorithm,
Digits = digits,
Period = period,
Counter = counter
};
if (!auth.IsValid())
{
throw new ArgumentException("Authenticator is not valid.");
}
return(auth);
}
public static Authenticator FromOtpAuthMigrationAuthenticator(OtpAuthMigration.Authenticator input)
{
string issuer;
string username;
// Google Auth may not have an issuer, just use the username instead
if (String.IsNullOrEmpty(input.Issuer))
{
issuer = input.Username.Trim().Truncate(IssuerMaxLength);
username = null;
}
else
{
issuer = input.Issuer.Trim().Truncate(IssuerMaxLength);
// For some odd reason the username field always follows a '[issuer]: [username]' format
username = input.Username.Replace($"{input.Issuer}: ", "").Trim().Truncate(UsernameMaxLength);
}
var type = input.Type switch
{
OtpAuthMigration.Type.Totp => AuthenticatorType.Totp,
OtpAuthMigration.Type.Hotp => AuthenticatorType.Hotp,
_ => throw new ArgumentException()
};
var algorithm = input.Algorithm switch
{
OtpAuthMigration.Algorithm.Sha1 => OtpHashMode.Sha1,
_ => throw new ArgumentException()
};
string secret;
try
{
secret = Base32Encoding.ToString(input.Secret);
secret = CleanSecret(secret, type);
}
catch
{
throw new ArgumentException();
}
var auth = new Authenticator
{
Issuer = issuer,
Username = username,
Algorithm = algorithm,
Type = type,
Secret = secret,
Counter = input.Counter,
Digits = DefaultDigits,
Period = DefaultPeriod,
Icon = Shared.Data.Icon.FindServiceKeyByName(issuer)
};
if (!auth.IsValid())
{
throw new ArgumentException();
}
return(auth);
}