message_parsers.cpp - openbmc/phosphor-net-ipmid - Gitiles

 #include "message_parsers.hpp"

 #include "endian.hpp"
 #include "main.hpp"
 #include "message.hpp"
 #include "sessions_manager.hpp"

 #include <memory>

 namespace message
 {

 namespace parser
 {

 std::tuple<std::shared_ptr<Message>, SessionHeader>
     unflatten(std::vector<uint8_t>& inPacket)
 {
     // Check if the packet has atleast the size of the RMCP Header
     if (inPacket.size() < sizeof(RmcpHeader_t))
     {
         throw std::runtime_error("RMCP Header missing");
     }

     auto rmcpHeaderPtr = reinterpret_cast<RmcpHeader_t*>(inPacket.data());

     // Verify if the fields in the RMCP header conforms to the specification
     if ((rmcpHeaderPtr->version != RMCP_VERSION) ||
         (rmcpHeaderPtr->rmcpSeqNum != RMCP_SEQ) ||
         (rmcpHeaderPtr->classOfMsg < static_cast<uint8_t>(ClassOfMsg::ASF) &&
          rmcpHeaderPtr->classOfMsg > static_cast<uint8_t>(ClassOfMsg::OEM)))
     {
         throw std::runtime_error("RMCP Header is invalid");
     }

     if (rmcpHeaderPtr->classOfMsg == static_cast<uint8_t>(ClassOfMsg::ASF))
     {
 #ifndef RMCP_PING
         throw std::runtime_error("RMCP Ping is not supported");
 #else
         return std::make_tuple(asfparser::unflatten(inPacket),
                                SessionHeader::IPMI15);
 #endif // RMCP_PING
     }

     auto sessionHeaderPtr = reinterpret_cast<BasicHeader_t*>(inPacket.data());

     // Read the Session Header and invoke the parser corresponding to the
     // header type
     switch (static_cast<SessionHeader>(sessionHeaderPtr->format.formatType))
     {
         case SessionHeader::IPMI15:
         {
             return std::make_tuple(ipmi15parser::unflatten(inPacket),
                                    SessionHeader::IPMI15);
         }
         case SessionHeader::IPMI20:
         {
             return std::make_tuple(ipmi20parser::unflatten(inPacket),
                                    SessionHeader::IPMI20);
         }
         default:
         {
             throw std::runtime_error("Invalid Session Header");
         }
     }
 }

 std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
                              SessionHeader authType,
                              std::shared_ptr<session::Session> session)
 {
     // Call the flatten routine based on the header type
     switch (authType)
     {
         case SessionHeader::IPMI15:
         {
             return ipmi15parser::flatten(outMessage, session);
         }
         case SessionHeader::IPMI20:
         {
             return ipmi20parser::flatten(outMessage, session);
         }
         default:
         {
             return {};
         }
     }
 }

 } // namespace parser

 namespace ipmi15parser
 {

 std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
 {
     if (inPacket.size() < sizeof(SessionHeader_t))
     {
         throw std::runtime_error("IPMI1.5 Session Header Missing");
     }

     auto header = reinterpret_cast<SessionHeader_t*>(inPacket.data());

     uint32_t sessionID = endian::from_ipmi(header->sessId);
     if (sessionID != session::sessionZero)
     {
         throw std::runtime_error("IPMI1.5 session packets are unsupported");
     }

     auto message = std::make_shared<Message>();

     message->payloadType = PayloadType::IPMI;
     message->bmcSessionID = session::sessionZero;
     message->sessionSeqNum = endian::from_ipmi(header->sessSeqNum);
     message->isPacketEncrypted = false;
     message->isPacketAuthenticated = false;
     message->rmcpMsgClass =
         static_cast<ClassOfMsg>(header->base.rmcp.classOfMsg);

     // Confirm the number of data bytes received correlates to
     // the packet length in the header
     size_t payloadLen = header->payloadLength;
     if ((payloadLen == 0) || (inPacket.size() < (sizeof(*header) + payloadLen)))
     {
         throw std::runtime_error("Invalid data length");
     }

     (message->payload)
         .assign(inPacket.data() + sizeof(SessionHeader_t),
                 inPacket.data() + sizeof(SessionHeader_t) + payloadLen);

     return message;
 }

 std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
                              std::shared_ptr<session::Session> session)
 {
     std::vector<uint8_t> packet(sizeof(SessionHeader_t));

     // Insert Session Header into the Packet
     auto header = reinterpret_cast<SessionHeader_t*>(packet.data());
     header->base.rmcp.version = parser::RMCP_VERSION;
     header->base.rmcp.reserved = 0x00;
     header->base.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
     header->base.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::IPMI);
     header->base.format.formatType =
         static_cast<uint8_t>(parser::SessionHeader::IPMI15);
     header->sessSeqNum = 0;
     header->sessId = endian::to_ipmi(outMessage->rcSessionID);

     header->payloadLength = static_cast<uint8_t>(outMessage->payload.size());

     // Insert the Payload into the Packet
     packet.insert(packet.end(), outMessage->payload.begin(),
                   outMessage->payload.end());

     // Insert the Session Trailer
     packet.resize(packet.size() + sizeof(SessionTrailer_t));
     auto trailer =
         reinterpret_cast<SessionTrailer_t*>(packet.data() + packet.size());
     trailer->legacyPad = 0x00;

     return packet;
 }

 } // namespace ipmi15parser

 namespace ipmi20parser
 {

 std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
 {
     // Check if the packet has atleast the Session Header
     if (inPacket.size() < sizeof(SessionHeader_t))
     {
         throw std::runtime_error("IPMI2.0 Session Header Missing");
     }

     auto header = reinterpret_cast<SessionHeader_t*>(inPacket.data());

     uint32_t sessionID = endian::from_ipmi(header->sessId);

     auto session = session::Manager::get().getSession(sessionID);
     if (!session)
     {
         throw std::runtime_error("RMCP+ message from unknown session");
     }

     auto message = std::make_shared<Message>();

     message->payloadType = static_cast<PayloadType>(header->payloadType & 0x3F);
     message->bmcSessionID = sessionID;
     message->sessionSeqNum = endian::from_ipmi(header->sessSeqNum);
     message->isPacketEncrypted =
         ((header->payloadType & PAYLOAD_ENCRYPT_MASK) ? true : false);
     message->isPacketAuthenticated =
         ((header->payloadType & PAYLOAD_AUTH_MASK) ? true : false);
     message->rmcpMsgClass =
         static_cast<ClassOfMsg>(header->base.rmcp.classOfMsg);

     // Confirm the number of data bytes received correlates to
     // the packet length in the header
     size_t payloadLen = endian::from_ipmi(header->payloadLength);
     if ((payloadLen == 0) || (inPacket.size() < (sizeof(*header) + payloadLen)))
     {
         throw std::runtime_error("Invalid data length");
     }

     bool integrityMismatch =
         session->isIntegrityAlgoEnabled() && !message->isPacketAuthenticated;
     bool encryptMismatch =
         session->isCryptAlgoEnabled() && !message->isPacketEncrypted;

     if (sessionID != session::sessionZero &&
         (integrityMismatch || encryptMismatch))
     {
         throw std::runtime_error("unencrypted or unauthenticated message");
     }

     if (message->isPacketAuthenticated)
     {
         if (!(internal::verifyPacketIntegrity(inPacket, message, payloadLen)))
         {
             throw std::runtime_error("Packet Integrity check failed");
         }
     }

     // Decrypt the payload if the payload is encrypted
     if (message->isPacketEncrypted)
     {
         // Assign the decrypted payload to the IPMI Message
         message->payload =
             internal::decryptPayload(inPacket, message, payloadLen);
     }
     else
     {
         message->payload.assign(inPacket.begin() + sizeof(SessionHeader_t),
                                 inPacket.begin() + sizeof(SessionHeader_t) +
                                     payloadLen);
     }

     return message;
 }

 std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
                              std::shared_ptr<session::Session> session)
 {
     std::vector<uint8_t> packet(sizeof(SessionHeader_t));

     SessionHeader_t* header = reinterpret_cast<SessionHeader_t*>(packet.data());
     header->base.rmcp.version = parser::RMCP_VERSION;
     header->base.rmcp.reserved = 0x00;
     header->base.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
     header->base.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::IPMI);
     header->base.format.formatType =
         static_cast<uint8_t>(parser::SessionHeader::IPMI20);
     header->payloadType = static_cast<uint8_t>(outMessage->payloadType);
     header->sessId = endian::to_ipmi(outMessage->rcSessionID);

     // Add session sequence number
     internal::addSequenceNumber(packet, session);

     size_t payloadLen = 0;

     // Encrypt the payload if needed
     if (outMessage->isPacketEncrypted)
     {
         header->payloadType |= PAYLOAD_ENCRYPT_MASK;
         auto cipherPayload = internal::encryptPayload(outMessage);
         payloadLen = cipherPayload.size();
         header->payloadLength = endian::to_ipmi<uint16_t>(cipherPayload.size());

         // Insert the encrypted payload into the outgoing IPMI packet
         packet.insert(packet.end(), cipherPayload.begin(), cipherPayload.end());
     }
     else
     {
         header->payloadLength =
             endian::to_ipmi<uint16_t>(outMessage->payload.size());
         payloadLen = outMessage->payload.size();

         // Insert the Payload into the Packet
         packet.insert(packet.end(), outMessage->payload.begin(),
                       outMessage->payload.end());
     }

     if (outMessage->isPacketAuthenticated)
     {
         header = reinterpret_cast<SessionHeader_t*>(packet.data());
         header->payloadType |= PAYLOAD_AUTH_MASK;
         internal::addIntegrityData(packet, outMessage, payloadLen);
     }

     return packet;
 }

 namespace internal
 {

 void addSequenceNumber(std::vector<uint8_t>& packet,
                        std::shared_ptr<session::Session> session)
 {
     SessionHeader_t* header = reinterpret_cast<SessionHeader_t*>(packet.data());

     if (header->sessId == session::sessionZero)
     {
         header->sessSeqNum = 0x00;
     }
     else
     {
         auto seqNum = session->sequenceNums.increment();
         header->sessSeqNum = endian::to_ipmi(seqNum);
     }
 }

 bool verifyPacketIntegrity(const std::vector<uint8_t>& packet,
                            const std::shared_ptr<Message> message,
                            size_t payloadLen)
 {
     /*
      * Padding bytes are added to cause the number of bytes in the data range
      * covered by the AuthCode(Integrity Data) field to be a multiple of 4 bytes
      * .If present each integrity Pad byte is set to FFh. The following logic
      * calculates the number of padding bytes added in the IPMI packet.
      */
     auto paddingLen = 4 - ((payloadLen + 2) & 3);

     auto sessTrailerPos = sizeof(SessionHeader_t) + payloadLen + paddingLen;

     // verify packet size includes trailer struct starts at sessTrailerPos
     if (packet.size() < (sessTrailerPos + sizeof(SessionTrailer_t)))
     {
         return false;
     }

     auto trailer = reinterpret_cast<const SessionTrailer_t*>(packet.data() +
                                                              sessTrailerPos);

     // Check trailer->padLength against paddingLen, both should match up,
     // return false if the lengths don't match
     if (trailer->padLength != paddingLen)
     {
         return false;
     }

     auto session = session::Manager::get().getSession(message->bmcSessionID);

     auto integrityAlgo = session->getIntegrityAlgo();

     // Check if Integrity data length is as expected, check integrity data
     // length is same as the length expected for the Integrity Algorithm that
     // was negotiated during the session open process.
     if ((packet.size() - sessTrailerPos - sizeof(SessionTrailer_t)) !=
         integrityAlgo->authCodeLength)
     {
         return false;
     }

     auto integrityIter = packet.cbegin();
     std::advance(integrityIter, sessTrailerPos + sizeof(SessionTrailer_t));

     // The integrity data is calculated from the AuthType/Format field up to and
     // including the field that immediately precedes the AuthCode field itself.
     size_t length = packet.size() - integrityAlgo->authCodeLength -
                     message::parser::RMCP_SESSION_HEADER_SIZE;

     return integrityAlgo->verifyIntegrityData(packet, length, integrityIter);
 }

 void addIntegrityData(std::vector<uint8_t>& packet,
                       const std::shared_ptr<Message> message, size_t payloadLen)
 {
     // The following logic calculates the number of padding bytes to be added to
     // IPMI packet. If needed each integrity Pad byte is set to FFh.
     auto paddingLen = 4 - ((payloadLen + 2) & 3);
     packet.insert(packet.end(), paddingLen, 0xFF);

     packet.resize(packet.size() + sizeof(SessionTrailer_t));

     auto trailer = reinterpret_cast<SessionTrailer_t*>(
         packet.data() + packet.size() - sizeof(SessionTrailer_t));

     trailer->padLength = paddingLen;
     trailer->nextHeader = parser::RMCP_MESSAGE_CLASS_IPMI;

     auto session = session::Manager::get().getSession(message->bmcSessionID);

     auto integrityData =
         session->getIntegrityAlgo()->generateIntegrityData(packet);

     packet.insert(packet.end(), integrityData.begin(), integrityData.end());
 }

 std::vector<uint8_t> decryptPayload(const std::vector<uint8_t>& packet,
                                     const std::shared_ptr<Message> message,
                                     size_t payloadLen)
 {
     auto session = session::Manager::get().getSession(message->bmcSessionID);

     return session->getCryptAlgo()->decryptPayload(
         packet, sizeof(SessionHeader_t), payloadLen);
 }

 std::vector<uint8_t> encryptPayload(std::shared_ptr<Message> message)
 {
     auto session = session::Manager::get().getSession(message->bmcSessionID);

     return session->getCryptAlgo()->encryptPayload(message->payload);
 }

 } // namespace internal

 } // namespace ipmi20parser

 #ifdef RMCP_PING
 namespace asfparser
 {
 std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
 {
     auto message = std::make_shared<Message>();

     auto header = reinterpret_cast<AsfMessagePing_t*>(inPacket.data());

     message->payloadType = PayloadType::IPMI;
     message->rmcpMsgClass = ClassOfMsg::ASF;
     message->asfMsgTag = header->msgTag;

     return message;
 }

 std::vector<uint8_t> flatten(uint8_t asfMsgTag)
 {
     std::vector<uint8_t> packet(sizeof(AsfMessagePong_t));

     // Insert RMCP header into the Packet
     auto header = reinterpret_cast<AsfMessagePong_t*>(packet.data());
     header->ping.rmcp.version = parser::RMCP_VERSION;
     header->ping.rmcp.reserved = 0x00;
     header->ping.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
     header->ping.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::ASF);

     // No OEM-specific capabilities exist, therefore the second
     // IANA Enterprise Number contains the same IANA(4542)
     header->ping.iana = header->iana = endian::to_ipmi(parser::ASF_IANA);
     header->ping.msgType = static_cast<uint8_t>(RmcpMsgType::PONG);
     header->ping.msgTag = asfMsgTag;
     header->ping.reserved = 0x00;
     header->ping.dataLen =
         parser::RMCP_ASF_PONG_DATA_LEN; // as per spec 13.2.4,

     header->iana = parser::ASF_IANA;
     header->oemDefined = 0x00;
     header->suppEntities = parser::ASF_SUPP_ENT;
     header->suppInteract = parser::ASF_SUPP_INT;
     header->reserved1 = 0x00;
     header->reserved2 = 0x00;

     return packet;
 }

 } // namespace asfparser
 #endif // RMCP_PING

 } // namespace message
	#include "message_parsers.hpp"

	#include "endian.hpp"
	#include "main.hpp"
	#include "message.hpp"
	#include "sessions_manager.hpp"

	#include <memory>

	namespace message
	{

	namespace parser
	{

	std::tuple<std::shared_ptr<Message>, SessionHeader>
	unflatten(std::vector<uint8_t>& inPacket)
	{
	// Check if the packet has atleast the size of the RMCP Header
	if (inPacket.size() < sizeof(RmcpHeader_t))
	{
	throw std::runtime_error("RMCP Header missing");
	}

	auto rmcpHeaderPtr = reinterpret_cast<RmcpHeader_t*>(inPacket.data());

	// Verify if the fields in the RMCP header conforms to the specification
	if ((rmcpHeaderPtr->version != RMCP_VERSION) \|\|
	(rmcpHeaderPtr->rmcpSeqNum != RMCP_SEQ) \|\|
	(rmcpHeaderPtr->classOfMsg < static_cast<uint8_t>(ClassOfMsg::ASF) &&
	rmcpHeaderPtr->classOfMsg > static_cast<uint8_t>(ClassOfMsg::OEM)))
	{
	throw std::runtime_error("RMCP Header is invalid");
	}

	if (rmcpHeaderPtr->classOfMsg == static_cast<uint8_t>(ClassOfMsg::ASF))
	{
	#ifndef RMCP_PING
	throw std::runtime_error("RMCP Ping is not supported");
	#else
	return std::make_tuple(asfparser::unflatten(inPacket),
	SessionHeader::IPMI15);
	#endif // RMCP_PING
	}

	auto sessionHeaderPtr = reinterpret_cast<BasicHeader_t*>(inPacket.data());

	// Read the Session Header and invoke the parser corresponding to the
	// header type
	switch (static_cast<SessionHeader>(sessionHeaderPtr->format.formatType))
	{
	case SessionHeader::IPMI15:
	{
	return std::make_tuple(ipmi15parser::unflatten(inPacket),
	SessionHeader::IPMI15);
	}
	case SessionHeader::IPMI20:
	{
	return std::make_tuple(ipmi20parser::unflatten(inPacket),
	SessionHeader::IPMI20);
	}
	default:
	{
	throw std::runtime_error("Invalid Session Header");
	}
	}
	}

	std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
	SessionHeader authType,
	std::shared_ptr<session::Session> session)
	{
	// Call the flatten routine based on the header type
	switch (authType)
	{
	case SessionHeader::IPMI15:
	{
	return ipmi15parser::flatten(outMessage, session);
	}
	case SessionHeader::IPMI20:
	{
	return ipmi20parser::flatten(outMessage, session);
	}
	default:
	{
	return {};
	}
	}
	}

	} // namespace parser

	namespace ipmi15parser
	{

	std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
	{
	if (inPacket.size() < sizeof(SessionHeader_t))
	{
	throw std::runtime_error("IPMI1.5 Session Header Missing");
	}

	auto header = reinterpret_cast<SessionHeader_t*>(inPacket.data());

	uint32_t sessionID = endian::from_ipmi(header->sessId);
	if (sessionID != session::sessionZero)
	{
	throw std::runtime_error("IPMI1.5 session packets are unsupported");
	}

	auto message = std::make_shared<Message>();

	message->payloadType = PayloadType::IPMI;
	message->bmcSessionID = session::sessionZero;
	message->sessionSeqNum = endian::from_ipmi(header->sessSeqNum);
	message->isPacketEncrypted = false;
	message->isPacketAuthenticated = false;
	message->rmcpMsgClass =
	static_cast<ClassOfMsg>(header->base.rmcp.classOfMsg);

	// Confirm the number of data bytes received correlates to
	// the packet length in the header
	size_t payloadLen = header->payloadLength;
	if ((payloadLen == 0) \|\| (inPacket.size() < (sizeof(*header) + payloadLen)))
	{
	throw std::runtime_error("Invalid data length");
	}

	(message->payload)
	.assign(inPacket.data() + sizeof(SessionHeader_t),
	inPacket.data() + sizeof(SessionHeader_t) + payloadLen);

	return message;
	}

	std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
	std::shared_ptr<session::Session> session)
	{
	std::vector<uint8_t> packet(sizeof(SessionHeader_t));

	// Insert Session Header into the Packet
	auto header = reinterpret_cast<SessionHeader_t*>(packet.data());
	header->base.rmcp.version = parser::RMCP_VERSION;
	header->base.rmcp.reserved = 0x00;
	header->base.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
	header->base.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::IPMI);
	header->base.format.formatType =
	static_cast<uint8_t>(parser::SessionHeader::IPMI15);
	header->sessSeqNum = 0;
	header->sessId = endian::to_ipmi(outMessage->rcSessionID);

	header->payloadLength = static_cast<uint8_t>(outMessage->payload.size());

	// Insert the Payload into the Packet
	packet.insert(packet.end(), outMessage->payload.begin(),
	outMessage->payload.end());

	// Insert the Session Trailer
	packet.resize(packet.size() + sizeof(SessionTrailer_t));
	auto trailer =
	reinterpret_cast<SessionTrailer_t*>(packet.data() + packet.size());
	trailer->legacyPad = 0x00;

	return packet;
	}

	} // namespace ipmi15parser

	namespace ipmi20parser
	{

	std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
	{
	// Check if the packet has atleast the Session Header
	if (inPacket.size() < sizeof(SessionHeader_t))
	{
	throw std::runtime_error("IPMI2.0 Session Header Missing");
	}

	auto header = reinterpret_cast<SessionHeader_t*>(inPacket.data());

	uint32_t sessionID = endian::from_ipmi(header->sessId);

	auto session = session::Manager::get().getSession(sessionID);
	if (!session)
	{
	throw std::runtime_error("RMCP+ message from unknown session");
	}

	auto message = std::make_shared<Message>();

	message->payloadType = static_cast<PayloadType>(header->payloadType & 0x3F);
	message->bmcSessionID = sessionID;
	message->sessionSeqNum = endian::from_ipmi(header->sessSeqNum);
	message->isPacketEncrypted =
	((header->payloadType & PAYLOAD_ENCRYPT_MASK) ? true : false);
	message->isPacketAuthenticated =
	((header->payloadType & PAYLOAD_AUTH_MASK) ? true : false);
	message->rmcpMsgClass =
	static_cast<ClassOfMsg>(header->base.rmcp.classOfMsg);

	// Confirm the number of data bytes received correlates to
	// the packet length in the header
	size_t payloadLen = endian::from_ipmi(header->payloadLength);
	if ((payloadLen == 0) \|\| (inPacket.size() < (sizeof(*header) + payloadLen)))
	{
	throw std::runtime_error("Invalid data length");
	}

	bool integrityMismatch =
	session->isIntegrityAlgoEnabled() && !message->isPacketAuthenticated;
	bool encryptMismatch =
	session->isCryptAlgoEnabled() && !message->isPacketEncrypted;

	if (sessionID != session::sessionZero &&
	(integrityMismatch \|\| encryptMismatch))
	{
	throw std::runtime_error("unencrypted or unauthenticated message");
	}

	if (message->isPacketAuthenticated)
	{
	if (!(internal::verifyPacketIntegrity(inPacket, message, payloadLen)))
	{
	throw std::runtime_error("Packet Integrity check failed");
	}
	}

	// Decrypt the payload if the payload is encrypted
	if (message->isPacketEncrypted)
	{
	// Assign the decrypted payload to the IPMI Message
	message->payload =
	internal::decryptPayload(inPacket, message, payloadLen);
	}
	else
	{
	message->payload.assign(inPacket.begin() + sizeof(SessionHeader_t),
	inPacket.begin() + sizeof(SessionHeader_t) +
	payloadLen);
	}

	return message;
	}

	std::vector<uint8_t> flatten(std::shared_ptr<Message> outMessage,
	std::shared_ptr<session::Session> session)
	{
	std::vector<uint8_t> packet(sizeof(SessionHeader_t));

	SessionHeader_t* header = reinterpret_cast<SessionHeader_t*>(packet.data());
	header->base.rmcp.version = parser::RMCP_VERSION;
	header->base.rmcp.reserved = 0x00;
	header->base.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
	header->base.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::IPMI);
	header->base.format.formatType =
	static_cast<uint8_t>(parser::SessionHeader::IPMI20);
	header->payloadType = static_cast<uint8_t>(outMessage->payloadType);
	header->sessId = endian::to_ipmi(outMessage->rcSessionID);

	// Add session sequence number
	internal::addSequenceNumber(packet, session);

	size_t payloadLen = 0;

	// Encrypt the payload if needed
	if (outMessage->isPacketEncrypted)
	{
	header->payloadType \|= PAYLOAD_ENCRYPT_MASK;
	auto cipherPayload = internal::encryptPayload(outMessage);
	payloadLen = cipherPayload.size();
	header->payloadLength = endian::to_ipmi<uint16_t>(cipherPayload.size());

	// Insert the encrypted payload into the outgoing IPMI packet
	packet.insert(packet.end(), cipherPayload.begin(), cipherPayload.end());
	}
	else
	{
	header->payloadLength =
	endian::to_ipmi<uint16_t>(outMessage->payload.size());
	payloadLen = outMessage->payload.size();

	// Insert the Payload into the Packet
	packet.insert(packet.end(), outMessage->payload.begin(),
	outMessage->payload.end());
	}

	if (outMessage->isPacketAuthenticated)
	{
	header = reinterpret_cast<SessionHeader_t*>(packet.data());
	header->payloadType \|= PAYLOAD_AUTH_MASK;
	internal::addIntegrityData(packet, outMessage, payloadLen);
	}

	return packet;
	}

	namespace internal
	{

	void addSequenceNumber(std::vector<uint8_t>& packet,
	std::shared_ptr<session::Session> session)
	{
	SessionHeader_t* header = reinterpret_cast<SessionHeader_t*>(packet.data());

	if (header->sessId == session::sessionZero)
	{
	header->sessSeqNum = 0x00;
	}
	else
	{
	auto seqNum = session->sequenceNums.increment();
	header->sessSeqNum = endian::to_ipmi(seqNum);
	}
	}

	bool verifyPacketIntegrity(const std::vector<uint8_t>& packet,
	const std::shared_ptr<Message> message,
	size_t payloadLen)
	{
	/*
	* Padding bytes are added to cause the number of bytes in the data range
	* covered by the AuthCode(Integrity Data) field to be a multiple of 4 bytes
	* .If present each integrity Pad byte is set to FFh. The following logic
	* calculates the number of padding bytes added in the IPMI packet.
	*/
	auto paddingLen = 4 - ((payloadLen + 2) & 3);

	auto sessTrailerPos = sizeof(SessionHeader_t) + payloadLen + paddingLen;

	// verify packet size includes trailer struct starts at sessTrailerPos
	if (packet.size() < (sessTrailerPos + sizeof(SessionTrailer_t)))
	{
	return false;
	}

	auto trailer = reinterpret_cast<const SessionTrailer_t*>(packet.data() +
	sessTrailerPos);

	// Check trailer->padLength against paddingLen, both should match up,
	// return false if the lengths don't match
	if (trailer->padLength != paddingLen)
	{
	return false;
	}

	auto session = session::Manager::get().getSession(message->bmcSessionID);

	auto integrityAlgo = session->getIntegrityAlgo();

	// Check if Integrity data length is as expected, check integrity data
	// length is same as the length expected for the Integrity Algorithm that
	// was negotiated during the session open process.
	if ((packet.size() - sessTrailerPos - sizeof(SessionTrailer_t)) !=
	integrityAlgo->authCodeLength)
	{
	return false;
	}

	auto integrityIter = packet.cbegin();
	std::advance(integrityIter, sessTrailerPos + sizeof(SessionTrailer_t));

	// The integrity data is calculated from the AuthType/Format field up to and
	// including the field that immediately precedes the AuthCode field itself.
	size_t length = packet.size() - integrityAlgo->authCodeLength -
	message::parser::RMCP_SESSION_HEADER_SIZE;

	return integrityAlgo->verifyIntegrityData(packet, length, integrityIter);
	}

	void addIntegrityData(std::vector<uint8_t>& packet,
	const std::shared_ptr<Message> message, size_t payloadLen)
	{
	// The following logic calculates the number of padding bytes to be added to
	// IPMI packet. If needed each integrity Pad byte is set to FFh.
	auto paddingLen = 4 - ((payloadLen + 2) & 3);
	packet.insert(packet.end(), paddingLen, 0xFF);

	packet.resize(packet.size() + sizeof(SessionTrailer_t));

	auto trailer = reinterpret_cast<SessionTrailer_t*>(
	packet.data() + packet.size() - sizeof(SessionTrailer_t));

	trailer->padLength = paddingLen;
	trailer->nextHeader = parser::RMCP_MESSAGE_CLASS_IPMI;

	auto session = session::Manager::get().getSession(message->bmcSessionID);

	auto integrityData =
	session->getIntegrityAlgo()->generateIntegrityData(packet);

	packet.insert(packet.end(), integrityData.begin(), integrityData.end());
	}

	std::vector<uint8_t> decryptPayload(const std::vector<uint8_t>& packet,
	const std::shared_ptr<Message> message,
	size_t payloadLen)
	{
	auto session = session::Manager::get().getSession(message->bmcSessionID);

	return session->getCryptAlgo()->decryptPayload(
	packet, sizeof(SessionHeader_t), payloadLen);
	}

	std::vector<uint8_t> encryptPayload(std::shared_ptr<Message> message)
	{
	auto session = session::Manager::get().getSession(message->bmcSessionID);

	return session->getCryptAlgo()->encryptPayload(message->payload);
	}

	} // namespace internal

	} // namespace ipmi20parser

	#ifdef RMCP_PING
	namespace asfparser
	{
	std::shared_ptr<Message> unflatten(std::vector<uint8_t>& inPacket)
	{
	auto message = std::make_shared<Message>();

	auto header = reinterpret_cast<AsfMessagePing_t*>(inPacket.data());

	message->payloadType = PayloadType::IPMI;
	message->rmcpMsgClass = ClassOfMsg::ASF;
	message->asfMsgTag = header->msgTag;

	return message;
	}

	std::vector<uint8_t> flatten(uint8_t asfMsgTag)
	{
	std::vector<uint8_t> packet(sizeof(AsfMessagePong_t));

	// Insert RMCP header into the Packet
	auto header = reinterpret_cast<AsfMessagePong_t*>(packet.data());
	header->ping.rmcp.version = parser::RMCP_VERSION;
	header->ping.rmcp.reserved = 0x00;
	header->ping.rmcp.rmcpSeqNum = parser::RMCP_SEQ;
	header->ping.rmcp.classOfMsg = static_cast<uint8_t>(ClassOfMsg::ASF);

	// No OEM-specific capabilities exist, therefore the second
	// IANA Enterprise Number contains the same IANA(4542)
	header->ping.iana = header->iana = endian::to_ipmi(parser::ASF_IANA);
	header->ping.msgType = static_cast<uint8_t>(RmcpMsgType::PONG);
	header->ping.msgTag = asfMsgTag;
	header->ping.reserved = 0x00;
	header->ping.dataLen =
	parser::RMCP_ASF_PONG_DATA_LEN; // as per spec 13.2.4,

	header->iana = parser::ASF_IANA;
	header->oemDefined = 0x00;
	header->suppEntities = parser::ASF_SUPP_ENT;
	header->suppInteract = parser::ASF_SUPP_INT;
	header->reserved1 = 0x00;
	header->reserved2 = 0x00;

	return packet;
	}

	} // namespace asfparser
	#endif // RMCP_PING

	} // namespace message