Exemple #1
0
 /// <summary>
 ///
 /// </summary>
 /// <param name="joinAcceptMessage"></param>
 /// <param name="appKey"></param>
 public CalculatedMIC(JoinRequestMessage joinRequestMessage, byte[] appKey)
 {
     if (appKey != null && appKey.Length == 16)
     {
         CryptoService crypto = new CryptoService();
         // cmac = aes128_cmac(AppKey, MHDR | AppEUI | DevEUI | DevNonce)
         // MIC = cmac[0..3]
         byte[] data = new byte[joinRequestMessage.RawData.Length + 1];
         joinRequestMessage.Parent.Mhdr.RawData.CopyTo(data.AsSpan()); // [1]
         joinRequestMessage.RawData.CopyTo(data.AsSpan(1));
         byte[] fullCAMC = crypto.AESCMAC(appKey, data);
         RawData = fullCAMC.AsSpan(0, 4).ToArray();
         IsValid = true;
     }
     else
     {
         RawData = Array.Empty <byte>();
         IsValid = false;
     }
 }