The MATLAB encryption function needs to be re written in the form of a function which accepts plain text as input from NetSim and provides cipher text as output.

Then you can write a function which takes care of interaction with MATLAB like:

char* fn_netsim_matlab_run(char* str, int* len) { sprintf(buf, "payload='"); strcat(buf, str); strcat(buf, "'"); engEvalString(ep, buf); return str; }

For the above function to receive and pass the packet payload to MATLAB, a call should be made from the copy_payload() function present in the Application.c file as shown below:

void copy_payload(UINT8 real[],NetSim_PACKET* packet,unsigned int* payload,APP_INFO* info) { .... real=fn_netsim_matlab_run(real, payload);

​...

}