public static bool validatePlainSecret(string secret, OtpSecretEncoding encoding)
{
if (encoding == OtpSecretEncoding.Base32)
{
if (Regex.IsMatch(secret, @"^(?:[A-Z2-7]{8})*(?:[A-Z2-7]{2}={6}|[A-Z2-7]{4}={4}|[A-Z2-7]{5}={3}|[A-Z2-7]{7}=)?$"))
{
return(true);
}
else
{
throw new InvalidBase32FormatException("Invalid Base32 format!\n\nRequired length: 8 * n (if shorter, fill up with =)\n\nAllowed characters:\nABCDEFGHIJKLMNOPQRSTUVWXYZ234567=\n\nRegex:\n^(?:[A-Z2-7]{8})*(?:[A-Z2-7]{2}={6}|[A-Z2-7]{4}={4}|[A-Z2-7]{5}={3}|[A-Z2-7]{7}=)+$");
}
}
else if (encoding == OtpSecretEncoding.Base64)
{
if (Regex.IsMatch(secret, @"^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$"))
{
return(true);
}
else
{
throw new InvalidBase64FormatException("Invalid Base32 format!\n\nRequired length: 4 * n (if shorter, fill up with =)\n\nAllowed characters:\nabcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789=\n\nRegex:\n^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$");
}
}
else if (encoding == OtpSecretEncoding.Hex)
{
if (Regex.IsMatch(secret, @"^([A-Fa-f0-9]{2})+$"))
{
return(true);
}
else
{
throw new InvalidHexFormatException("Invalid Hex format!\n\nRequired length: 2 * n\n\nAllowed characters:\nabcdefABCDEF0123456789\n\nRegex:\n^([a-fA-F0-9]{2})+$");
}
}
else if (encoding == OtpSecretEncoding.UTF8)
{
return(true);
}
throw new InvalidOperationException("No Encoding given!");
}
public static string correctPlainSecret(string secret, OtpSecretEncoding encoding)
{
secret = secret.Replace("=", "").Replace(" ", "");
int secretLength = secret.Length;
if (encoding == OtpSecretEncoding.Base32)
{
secret = secret.ToUpper();
if (secretLength % 8 == 2 || secretLength % 8 == 4 || secretLength % 8 == 5 || secretLength % 8 == 7)
{
secret += new string('=', 8 - secretLength % 8);
}
}
else if (encoding == OtpSecretEncoding.Base64)
{
if (secretLength % 4 == 2 || secretLength % 4 == 3)
{
secret += new string('=', 4 - secretLength % 4);
}
}
return(secret);
}
