static void Main(string[] args)
{
#region .: Instanciando Objectos :.
Encrypt encode = new Encrypt();
Decrypt decode = new Decrypt();
EncryptedTextModel text = new EncryptedTextModel();
#endregion
Console.WriteLine("#############################################################");
Console.WriteLine("################### Programa de Segurança ###################");
Console.WriteLine("#############################################################");
Console.WriteLine("");
Console.ReadKey();
Console.WriteLine("########## Texto Inicial ##########\n");
Console.WriteLine($"{text.textToEncrypt}");
Console.ReadKey();
#region .: Codificando e Descodificando
decode.Descodificar(encode.Codificar(text.textToEncrypt, text.secretToEncrypt), text.secretToEncrypt);
#endregion
Console.ReadLine();
}
public static string DecodedWith(this EncryptedTextModel model, X509Certificate2 certificate)
{
if (certificate is null)
{
return("ERROR: No key provided to decode EncryptedText");
}
if (!certificate.HasPrivateKey)
{
return("ERROR: Certificate has no private key to be able to decode EncryptedText");
}
string certKeyId = certificate.ToKeyId();
string pubKeyHash = certificate.ToPubKeyHash();
if (pubKeyHash is null)
{
return("ERROR: Non-RSA certificate is not currently supported");
}
if (model.ReadingKeys.SkipNulls().None())
{
return("ERROR: No reading keys able to decode EncryptedText");
}
var authorizedKey = model.ReadingKeys.FirstOrDefault(rk => rk.PublicKeyHash == pubKeyHash && rk.ReaderId == certKeyId);
if (authorizedKey is null)
{
return("ERROR: Your key does not match one of the authorized reading keys");
}
string cipher = model.Cipher.WithDefault("AES256").ToUpperInvariant();
if (cipher != "AES256")
{
return($"ERROR: Cipher {cipher} is not currently supported");
}
if (model.CipherText.None())
{
return(null);
}
using var rsaAlgo = certificate.GetRSAPrivateKey();
var aesKey = RSADecrypt(rsaAlgo, authorizedKey.EncryptedKey);
var aesIV = RSADecrypt(rsaAlgo, authorizedKey.EncryptedIV);
var jsonBytes = AES256Decrypt(model.CipherText, aesKey, aesIV);
if (jsonBytes[0] != 17)
{
return("ERROR: Something went wrong while decrypting the content. Unexpected initial bytes");
}
var skipTagAndSize = jsonBytes[1..].ILIntDecode().ILIntSize() + 1;