ESP-NOW help with encryption (PMK/LMK)

[MStackoverflow]

Hi,

I have to do a module for a project and security is needed. I want to encrypt the communication.

I've read the docs and I can't make the esp_now_peer_info_t::encrypt work.

I've made a peers on both sides (master/slave), put the same peer LMK, put the same PMK, set the slave into APSTA mode.
when I put

Code: Select all

slave.encrypt = true

, the Master says the message sent was successful but the slave does not receive it.

Can someone guide me through how encryption work?

[MStackoverflow]

Hi, sorry for double posting.

Anyone can help me?

[iParcelBox]

Did you ever manage to resolve this? I'm having exactly the same issue - sender says message sent OK, but never received on the slave.

[Ankit Siddhapura]

I am facing same issue.
Seems packet received at MAC layer and discarded before reaches to application layer.

Guys, did you find root cause or solution of this issue?

[MStackoverflow]

I manage to make it work a while ago. I don't remember how I solved the problem. I think it has to do with the call order of functions.

Here's the setup code (Slave and master don't have the same meaning for me):
Note that you could use memcpy instead of loops.

Master Side (Slave is a custom Object)

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 WiFi.mode(WIFI_MODE_STA);
 WiFi.disconnect();
 esp_now_init();
 esp_now_register_recv_cb(OnDataRecv);
 esp_now_register_send_cb(OnDataSent);
 esp_now_set_pmk(key);
 esp_wifi_set_protocol( WIFI_IF_AP, WIFI_PROTOCOL_LR);
 
 for(int j=0;j<6;j++){
	slave.info.peer_addr[j] = slave.macAddress[j]; 
 }
 for(int j=0;j<16;j++){
 	slave.info.lmk[j] = key[j];
 }
slave.info.channel = 12;
slave.info.encrypt = 1;
esp_now_add_peer(&slave[i].info);

Slave Side (master is a custom object)

Code: Select all

for(int i=0;i<=6;i++){
    master.peer_addr[i] = masterMac[i];
  }

  for(int i=0;i<16;i++){
    master.lmk[i] = key[i];
  }
  
  master.channel = 12;
  master.encrypt = 1;
  
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  esp_now_init();
  esp_now_register_send_cb(OnDataSent);
  esp_now_register_recv_cb(OnDataRecv);
  esp_now_set_pmk(key);
  esp_wifi_set_protocol( WIFI_IF_AP, WIFI_PROTOCOL_LR);
  esp_now_add_peer(&master);