Hi,
I am sorry for using wrong terms. I started the job several days ago and learn many terms from Wikipedia. Let me rephrase my problem.
You mentioned that the Freeradius Server use OpenSSL for encryption. The OpenSSL implements many encryption methods including AES which is a symmetric key cryptography. So there must be a key shared by both the server and the supplicant for AES to work. I would like to know where in the source code (which variable in which file) it is. I was not able to locate it.
Thanks for your tolerance and help.