static void Main() { const string original = "Very secret and important information that can not fall into the wrong hands."; var hybrid = new HybridEncryption(); var rsaParams = new RSAWithRSAParameterKey(); rsaParams.AssignNewKey(); var digitalSignature = new DigitalSignature(); digitalSignature.AssignNewKey(); Console.WriteLine(); try { var encryptedBlock = hybrid.EncryptData(Encoding.UTF8.GetBytes(original), rsaParams, digitalSignature); var decrpyted = hybrid.DecryptData(encryptedBlock, rsaParams, digitalSignature); Console.WriteLine("Original Message = " + original); Console.WriteLine(); Console.WriteLine("Message After Decryption = " + Encoding.UTF8.GetString(decrpyted)); } catch (CryptographicException ex) { Console.WriteLine("Error : " + ex.Message); } Console.ReadLine(); }
static void Main() { var document = Encoding.UTF8.GetBytes("Document to Sign"); byte[] hashedDocument; using (var sha256 = SHA256.Create()) { hashedDocument = sha256.ComputeHash(document); } var digitalSignature = new DigitalSignature(); digitalSignature.AssignNewKey(); var signature = digitalSignature.SignData(hashedDocument); var verified = digitalSignature.VerifySignature(hashedDocument, signature); Console.WriteLine(); Console.WriteLine(" Original Text = " + Encoding.Default.GetString(document)); Console.WriteLine(); Console.WriteLine(" Digital Signature = " + Convert.ToBase64String(signature)); Console.WriteLine(); Console.WriteLine(verified ? "The digital signature has been correctly verified." : "The digital signature has NOT been correctly verified."); Console.ReadLine(); }
public byte[] DecryptData(EncryptedPacket encryptedPacket, RSAWithRSAParameterKey rsaParams, DigitalSignature digitalSignature) { var decryptedSessionKey = rsaParams.DecryptData(encryptedPacket.EncryptedSessionKey); using (var hmac = new HMACSHA256(decryptedSessionKey)) { var hmacToCheck = hmac.ComputeHash(encryptedPacket.EncryptedData); if (!Compare(encryptedPacket.Hmac, hmacToCheck)){ throw new CryptographicException( "HMAC for decryption does not match encrypted packet."); } if (!digitalSignature.VerifySignature(encryptedPacket.Hmac, encryptedPacket.Signature)){ throw new CryptographicException( "Digital Signature can not be verified."); } } var decryptedData = _aes.Decrypt(encryptedPacket.EncryptedData, decryptedSessionKey, encryptedPacket.Iv); return decryptedData; }
public EncryptedPacket EncryptData(byte[] original, RSAWithRSAParameterKey rsaParams, DigitalSignature digitalSignature) { var sessionKey = _aes.GenerateRandomNumber(32); var encryptedPacket = new EncryptedPacket { Iv = _aes.GenerateRandomNumber(16) }; encryptedPacket.EncryptedData = _aes.Encrypt(original, sessionKey, encryptedPacket.Iv); encryptedPacket.EncryptedSessionKey = rsaParams.EncryptData(sessionKey); using (var hmac = new HMACSHA256(sessionKey)) { encryptedPacket.Hmac = hmac.ComputeHash(encryptedPacket.EncryptedData); } encryptedPacket.Signature = digitalSignature.SignData(encryptedPacket.Hmac); return encryptedPacket; }