/// <summary>First signs the data and then encrypts it.</summary>
/// <param name="UnecryptedData">The data to sign and encrypt.</param>
/// <returns>The signed and encrypted data.</returns>
public void SignAndEncrypt(SecurityDataMessage sdm)
{
if (_closed)
{
throw new Exception("SecurityHandler: closed");
}
// Get the sequence id and increment the counter
int seqid = ++_last_outgoing_seqid;
// We ask for an update at the half life and every 1000 packets thereafter
if (seqid == HALF_LIFE || (seqid > HALF_LIFE && seqid % 1000 == 0))
{
if (Update != null)
{
Update(Epoch, EventArgs.Empty);
}
}
sdm.Seqid = seqid;
sdm.Epoch = Epoch;
sdm.Sign(_outgoing_auth);
sdm.Encrypt(_encryptor);
}
public void Incoming()
{
SymmetricAlgorithm sa = new RijndaelManaged();
SymmetricEncryption se = new SymmetricEncryption(sa);
HashAlgorithm hash = new SHA1CryptoServiceProvider();
int spi = 12345;
int epoch = 67890;
int seqid = 1222;
Random rand = new Random();
byte[] data = new byte[144];
rand.NextBytes(data);
MemBlock mdata = MemBlock.Reference(data);
byte[] to_sign = new byte[12 + data.Length];
int pos = 0;
NumberSerializer.WriteInt(spi, to_sign, pos);
pos += 4;
NumberSerializer.WriteInt(epoch, to_sign, pos);
pos += 4;
NumberSerializer.WriteInt(seqid, to_sign, pos);
pos += 4;
data.CopyTo(to_sign, pos);
byte[] signature = hash.ComputeHash(to_sign);
byte[] to_encrypt = new byte[4 + data.Length + signature.Length];
pos = 0;
NumberSerializer.WriteInt(data.Length, to_encrypt, pos);
pos += 4;
data.CopyTo(to_encrypt, pos);
pos += data.Length;
signature.CopyTo(to_encrypt, pos);
byte[] encrypted = se.EncryptData(to_encrypt);
byte[] packet = new byte[12 + encrypted.Length];
pos = 0;
NumberSerializer.WriteInt(spi, packet, pos);
pos += 4;
NumberSerializer.WriteInt(epoch, packet, pos);
pos += 4;
NumberSerializer.WriteInt(seqid, packet, pos);
pos += 4;
encrypted.CopyTo(packet, pos);
MemBlock mpacket = MemBlock.Reference(packet);
// check
SecurityDataMessage sdm_e = new SecurityDataMessage(packet);
sdm_e.Decrypt(se);
Assert.AreEqual(spi, sdm_e.SPI, "SPI");
Assert.AreEqual(epoch, sdm_e.Epoch, "Epoch");
Assert.AreEqual(seqid, sdm_e.Seqid, "Seqid");
Assert.AreEqual(mdata, sdm_e.Data, "Data");
Assert.IsTrue(sdm_e.Verify(hash), "Signature");
Assert.AreEqual(mpacket, sdm_e.Packet, "Packet");
SecurityDataMessage sdm_d = new SecurityDataMessage();
sdm_d.SPI = spi;
sdm_d.Epoch = epoch;
sdm_d.Seqid = seqid;
sdm_d.Data = data;
sdm_d.Sign(hash);
sdm_d.Encrypt(se);
sdm_e = new SecurityDataMessage(sdm_d.Packet);
sdm_e.Decrypt(se);
Assert.AreEqual(spi, sdm_e.SPI, "SPI");
Assert.AreEqual(epoch, sdm_e.Epoch, "Epoch");
Assert.AreEqual(seqid, sdm_e.Seqid, "Seqid");
Assert.AreEqual(mdata, sdm_e.Data, "Data");
Assert.IsTrue(sdm_e.Verify(hash), "Signature");
Assert.AreEqual(sdm_d.Packet, sdm_e.Packet, "Packet");
}