Method HandlePacketLoginEncryptionResponse

src/Protocol/Protocol17x.cpp:1508–1568

void cProtocol172::HandlePacketLoginEncryptionResponse(cByteBuffer & a_ByteBuffer)
{
	short EncKeyLength, EncNonceLength;
	a_ByteBuffer.ReadBEShort(EncKeyLength);
	AString EncKey;
	if (!a_ByteBuffer.ReadString(EncKey, EncKeyLength))
	{
		return;
	}
	a_ByteBuffer.ReadBEShort(EncNonceLength);
	AString EncNonce;
	if (!a_ByteBuffer.ReadString(EncNonce, EncNonceLength))
	{
		return;
	}
	if ((EncKeyLength > MAX_ENC_LEN) || (EncNonceLength > MAX_ENC_LEN))
	{
		LOGD("Too long encryption");
		m_Client->Kick("Hacked client");
		return;
	}

	// Decrypt EncNonce using privkey
	cRSAPrivateKey & rsaDecryptor = cRoot::Get()->GetServer()->GetPrivateKey();
	Int32 DecryptedNonce[MAX_ENC_LEN / sizeof(Int32)];
	int res = rsaDecryptor.Decrypt((const Byte *)EncNonce.data(), EncNonce.size(), (Byte *)DecryptedNonce, sizeof(DecryptedNonce));
	if (res != 4)
	{
		LOGD("Bad nonce length: got %d, exp %d", res, 4);
		m_Client->Kick("Hacked client");
		return;
	}
	if (ntohl(DecryptedNonce[0]) != (unsigned)(uintptr_t)this)
	{
		LOGD("Bad nonce value");
		m_Client->Kick("Hacked client");
		return;
	}
	
	// Decrypt the symmetric encryption key using privkey:
	Byte DecryptedKey[MAX_ENC_LEN];
	res = rsaDecryptor.Decrypt((const Byte *)EncKey.data(), EncKey.size(), DecryptedKey, sizeof(DecryptedKey));
	if (res != 16)
	{
		LOGD("Bad key length");
		m_Client->Kick("Hacked client");
		return;
	}
	
	StartEncryption(DecryptedKey);

	// Send login success:
	{
		cPacketizer Pkt(*this, 0x02);  // Login success packet
		Pkt.WriteString(Printf("%d", m_Client->GetUniqueID()));  // TODO: proper UUID
		Pkt.WriteString(m_Client->GetUsername());
	}