Method SendSessionCreated

libi2pd/SSU2Session.cpp:946–1040

	}

	void SSU2Session::SendSessionCreated (const uint8_t * X)
	{
		// we are Bob
		m_EphemeralKeys = i2p::transport::transports.GetNextX25519KeysPair ();
		m_SentHandshakePacket.reset (new HandshakePacket);
		auto ts = i2p::util::GetMillisecondsSinceEpoch ();
		m_SentHandshakePacket->sendTime = ts;

		uint8_t kh2[32];
		i2p::crypto::HKDF (m_NoiseState->m_CK, nullptr, 0, "SessCreateHeader", kh2, 32); // k_header_2 = HKDF(chainKey, ZEROLEN, "SessCreateHeader", 32)
		// fill packet
		Header& header = m_SentHandshakePacket->header;
		uint8_t * headerX = m_SentHandshakePacket->headerX,
				* payload = m_SentHandshakePacket->payload;
		header.h.connID = m_DestConnID; // dest id
		RAND_bytes (header.buf + 8, 4); // random packet num
		header.h.type = eSSU2SessionCreated;
		header.h.flags[0] = m_Version; // ver
		header.h.flags[1] = (uint8_t)i2p::context.GetNetID (); // netID
		header.h.flags[2] = 0; // flag
		memcpy (headerX, &m_SourceConnID, 8); // source id
		memset (headerX + 8, 0, 8); // token = 0
		memcpy (headerX + 16, m_EphemeralKeys->GetPublicKey (), 32); // Y
		// KDF for SessionCreated
		m_NoiseState->MixHash ( { {header.buf, 16}, {headerX, 16} } ); // h = SHA256(h || header)
		m_NoiseState->MixHash (headerX + 16, 32); // h = SHA256(h || bepk);
		uint8_t sharedSecret[32];
		m_EphemeralKeys->Agree (X, sharedSecret);
		m_NoiseState->MixKey (sharedSecret);
		// payload
		size_t maxPayloadSize = m_MaxPayloadSize - 48;
		size_t payloadSize = 0, offset = 0;
#if OPENSSL_PQ
        if (m_Version > 2 && m_PQKeys)
        {
            size_t cipherTextLen = m_PQKeys->GetCTLen ();
			std::vector<uint8_t> kemCiphertext(cipherTextLen);
			m_PQKeys->Encaps (kemCiphertext.data (), sharedSecret);
			if (!m_NoiseState->Encrypt (kemCiphertext.data (), payload, cipherTextLen))
			{
				LogPrint (eLogWarning, "SSU2: SessionCreated ML-KEM ciphertext section AEAD encryption failed");
				return;
			}
			offset = cipherTextLen + 16;
			m_NoiseState->MixHash (payload, offset); // encrypt ML-KEM frame
			m_NoiseState->MixKey (sharedSecret);
            payloadSize += offset;
        }
#endif
		payload[payloadSize] = eSSU2BlkDateTime;
		htobe16buf (payload + payloadSize + 1, 4);
		htobe32buf (payload + payloadSize + 3, (ts + 500)/1000);
		payloadSize += 7;
		payloadSize += CreateAddressBlock (payload + payloadSize, maxPayloadSize - payloadSize, m_RemoteEndpoint);
		if (m_RelayTag)
		{
			payload[payloadSize] = eSSU2BlkRelayTag;
			htobe16buf (payload + payloadSize + 1, 4);