Creating server with HighGMAC authentication and association

Hi, thanks for the response.

As per your suggestion, I tried to do it like this

// 1. GXDLMSServerLN.h
class CGXDLMSServerLN :
   public CGXDLMSBase
{
public:
   //Constructor.
   CGXDLMSServerLN(CGXDLMSAssociationLogicalName* ln,
       CGXDLMSIecHdlcSetup* hdlc) : CGXDLMSBase(ln, hdlc)
   {
       // CGXDLMSSecuritySetup* pSecurity = new CGXDLMSSecuritySetup("0.0.43.0.2.255");
       // CGXByteBuffer systemTitle;
       // set Authentication key and Block cipher key
       CGXByteBuffer AuthKey;
       CGXByteBuffer BlockKey;
       AuthKey.AddString("000102030405060708090A0B0C0D0E0F");
       BlockKey.AddString("D0D1D2D3D4D5D6D7D8D9DADBDCDDDEDF");
       // set frame counter
       uint32_t invocationCounter = 0;
       // add cipher
       CGXCipher* cipher = new CGXCipher("4150490000000001");
       cipher->SetAuthenticationKey(AuthKey);
       cipher->SetBlockCipherKey(BlockKey);
       cipher->SetSecurity(DLMS_SECURITY_AUTHENTICATION_ENCRYPTION);
       cipher->SetSecuritySuite(DLMS_SECURITY_SUITE_V0);
       cipher->SetInvocationCounter(invocationCounter);
   
       ln->SetClientSAP(10);
       ln->SetServerSAP(11);
       CGXByteBuffer password;
       password.AddString("API0001");
       ln->SetSecret(password);
   }
};

2. GXDLMSBase.cpp

/*
* Add invocation counter
*/
void AddInvocationCounter(CGXDLMSObjectCollection& items, CGXCipher* cipher)
{
   // Create a new Data object for the invocation counter with the standard logical name.
   CGXDLMSData* pData = new CGXDLMSData("0.0.43.1.0.255");
   // Set the initial value (as unsigned 32-bit integer).
   uint32_t initialValue = cipher->GetInvocationCounter();
   
   CGXDLMSVariant invocationCounter0(initialValue);
   pData->SetValue(invocationCounter0);
   
   // Add the object to the collection.
   items.push_back(pData);
}

// void AddInvocationCounter(CGXDLMSObjectCollection& items, CGXDLMSSecuritySetup* pSecurity)
// {
//     // CGXCipher* cipher = items..GetCipher();
//     CGXDLMSData* pData = new CGXDLMSData("0.0.43.1.0.255");
//     CGXDLMSVariant invocationCounter0;
//     invocationCounter0 = pSecurity->GetInvocationCounter();
//     pData->SetValue(invocationCounter0);
//     items.push_back(pData);
// }

/*
* Add security setup object
*/
CGXDLMSSecuritySetup* AddSecuritySetupHighGmac(CGXDLMSObjectCollection& items)
{
   CGXDLMSSecuritySetup* pSecurity = new CGXDLMSSecuritySetup("0.0.43.0.2.255");
   std::string secLn;
   pSecurity->GetLogicalName(secLn);
   std::cout << "SecuritySetup LN: " << secLn << std::endl;
   
   CGXByteBuffer serverSystemTitle, clientSystemTitle;
   serverSystemTitle.AddString("API 1");
   clientSystemTitle.AddString(nullptr); // Set client system title to null or empty if not used.
   // serverSystemTitle.AddIntAsString(12345);
   std::cout<<"server system title: "<< serverSystemTitle.ToString().c_str()<<std::endl;
   std::cout<<"server system title size: "<<serverSystemTitle.GetSize()<<std::endl;
   std::cout<<"server system title hex: "<<serverSystemTitle.ToHexString(false).c_str()<<std::endl;
   pSecurity->SetServerSystemTitle(serverSystemTitle);
   pSecurity->SetClientSystemTitle(clientSystemTitle);
   std::cout << "ServerSystemTitle size: " << pSecurity->GetServerSystemTitle().GetSize() << std::endl;
   std::cout << "ClientSystemTitle size: " << pSecurity->GetClientSystemTitle().GetSize() << std::endl;
   pSecurity->SetSecurityPolicy(DLMS_SECURITY_POLICY_AUTHENTICATED_ENCRYPTED);
   pSecurity->SetSecuritySuite(DLMS_SECURITY_SUITE_V0);
   pSecurity->SetVersion(0);
   items.push_back(pSecurity);
   return pSecurity;
}
/*
* Add highGMAC association
*/
CGXDLMSAssociationLogicalName* AddAssociationHighGmac(CGXDLMSObjectCollection& items, CGXDLMSSecuritySetup* pSecurity)
{
   CGXDLMSAssociationLogicalName* a = new CGXDLMSAssociationLogicalName("0.0.40.0.4.255");
   std::string ln;
   pSecurity->GetLogicalName(ln);
   a->GetAuthenticationMechanismName().SetMechanismId(
       DLMS_AUTHENTICATION_HIGH_GMAC);
   a->SetClientSAP(1);
   // a->SetServerSAP(1); // example, match your server address
   a->SetSecuritySetupReference(ln);
   a->GetXDLMSContextInfo().SetMaxReceivePduSize(512);
   a->GetXDLMSContextInfo().SetMaxSendPduSize(512);
   a->GetXDLMSContextInfo().SetConformance(
       (DLMS_CONFORMANCE)(
           DLMS_CONFORMANCE_BLOCK_TRANSFER_WITH_ACTION |
           DLMS_CONFORMANCE_GENERAL_PROTECTION |
           DLMS_CONFORMANCE_BLOCK_TRANSFER_WITH_SET_OR_WRITE |
           DLMS_CONFORMANCE_BLOCK_TRANSFER_WITH_GET_OR_READ |
           DLMS_CONFORMANCE_SET |
           DLMS_CONFORMANCE_SELECTIVE_ACCESS |
           DLMS_CONFORMANCE_ACTION |
           DLMS_CONFORMANCE_MULTIPLE_REFERENCES |
           DLMS_CONFORMANCE_GET));
   items.push_back(a);
   return a;
}
// Init
///////////////////////////////////////////////////////////////////////
//Add highgmac security and association objects.
CGXDLMSSecuritySetup* secHighGmac = AddSecuritySetupHighGmac(GetItems());
CGXDLMSAssociationLogicalName* assocHighGmac = AddAssociationHighGmac(GetItems(), secHighGmac);
uint64_t invocationCounterInit;
CGXDLMSSettings& settings = GetSettings();
AddInvocationCounter(GetItems(), GetCiphering()); // Set initial value as needed
std::string secRef = assocHighGmac->GetSecuritySetupReference();
std::cout << "Association SecuritySetupReference: " << secRef << std::endl;
// istarget stuff
bool CGXDLMSBase::IsTarget(
   unsigned long int serverAddress,
   unsigned long clientAddress)
{
   std::cout<< "IsTarget called with serverAddress: " << serverAddress
            << " and clientAddress: " << clientAddress << std::endl;
   // CGXDLMSSettings& settings = GetSettings();
   std::string name = "0.0.40.0.5.255";
   uint16_t pos;
   std::string lnTemp;
   unsigned char ret = 0;
   // std::vector<CGXDLMSObject*> associations;
   CGXDLMSAssociationLogicalName* ln = (CGXDLMSAssociationLogicalName*)GetItems().FindByLN(
                                       DLMS_OBJECT_TYPE_ASSOCIATION_LOGICAL_NAME, name);
   ln->GetLogicalName(lnTemp);
   std::cout << "Association Logical Name: " << lnTemp << std::endl;
   const unsigned short expectedServerAddress = ln->GetServerSAP();
   const unsigned short expectedClientAddress = ln->GetClientSAP();
   if (serverAddress == expectedServerAddress &&
       clientAddress == expectedClientAddress)
   {
       return true;
   }
   for (auto obj : GetItems())
   {
       if (obj->GetObjectType() == DLMS_OBJECT_TYPE_ASSOCIATION_LOGICAL_NAME)
       {
           auto assoc = static_cast<CGXDLMSAssociationLogicalName*>(obj);
           if (assoc->GetClientSAP() == clientAddress)
           {
               // Optionally check serverAddress, security setup, etc.
               // Set settings as needed
               std::string ln;
               // assoc->GetLogicalName(ln);
               CGXCipher* cipher = GetSettings().GetCipher();
               ln = "0.0.43.1.0.255";
               CGXDLMSData* invocationCounter = (CGXDLMSData*)GetItems().FindByLN(DLMS_OBJECT_TYPE_DATA, ln);
               if (invocationCounter) {
                   int value = invocationCounter->GetValue().ToInteger();
                   value++;
                   CGXDLMSVariant v;
                   v = value;
                   invocationCounter->SetValue(v);
                   std::cout << "Updated Invocation Counter Value: " << value << std::endl;
                   std::cout << "Invocation Counter Value: " << invocationCounter->GetValue().ToString().c_str() << std::endl;
                   if (cipher) {
                       cipher->SetInvocationCounter(value++);
                   }
               }
               return true;
           }
       }
   }
   return false;
   
   // return true;
   // return DLMS_SOURCE_DIAGNOSTIC_AUTHENTICATION_FAILURE;
}

currently it shows 
`Access error : Device reports a undefined object.`

i tried multiple times before, it either give me 

`Segmentation fault`

or

gurux.dlms.server.bin: src/GXBytebuffer.cpp:111: void CGXByteBuffer::SetPosition(long unsigned int): Assertion `!(value > m_Size)' failed.

I tried to follow the structure of C code. please show me where i did wrong. is it the object declaration? perhaps the usage or the place of code is wrong? can you provide minimal example on how to do this in cpp?

Thank you.

Regards,

jack

Hi Mikko

I'm looking forward for new example to be done, thank you for that.
I actually plan to have at least a connection with low authentication (password) and a connection with HighGMAC authentication, i presume that's what all of those headers file in include used for (GXDLMSServerLN, GXDLMSServerLN_47, GXDLMSServerSN, GXDLMSServerSN_47), am i right?

Hi Mikko, thank you, it's clear now
So if i want to add different security, what would be the best place for the code? can I just make another header file? or should i just put it inside the CGXDLMSBase::Init ?

Regards,
jack

Hi Mikko, thank you for the prompt response. I will try and report back to you.

Regards
jack

Hi Mikko, how're you doing?
I have tried adding highGMAC auth and a separate association, but haven't managed to do it. Will there be a new example of this in CPP?

Thank you
jack

Hi Mikko, thank you for the update on the schedule. In the meantime, i'll try again and report back my result here.

Regards
jack

Hi Mikko, hope you have a good day. Is there any update regarding HighGMAC example in C++?

Regards,
jack