v1.2.6 salting & hashing MACs implemented

src/globals.h

@@ -32,7 +32,7 @@ extern configData_t cfg;
 extern uint8_t mydata[];
 extern uint64_t uptimecounter;
 extern osjob_t sendjob;
-extern int macnum, blenum, countermode, screensaver, adrmode, lorasf, txpower, rlim;
+extern int macnum, blenum, countermode, screensaver, adrmode, lorasf, txpower, rlim, salt;
 extern bool joinstate;
 extern std::set<uint32_t> macs; 
 

src/main.cpp

@@ -187,7 +187,7 @@ void wifi_sniffer_loop(void * pvParameters) {
 
     configASSERT( ( ( uint32_t ) pvParameters ) == 1 ); // FreeRTOS check
     uint8_t channel = 1;
-    int nloop=0, lorawait=0;
+    int nloop=0, lorawait=0, salt = rand() % 256; // random int between 0 and 255 used for salting MAC hashes
 
   	while (true) {
         nloop++;
@@ -219,6 +219,7 @@ void wifi_sniffer_loop(void * pvParameters) {
                 macs.clear(); // clear macs container
                 macnum = 0;
                 u8x8.clearLine(0); u8x8.clearLine(1); // clear Display counter
+                salt = rand() % 256; // get new random int between 0 and 255 for salting MAC hashes
             }      
 
             // wait until payload is sent, while wifi scanning and mac counting task continues

src/main.h

@@ -1,5 +1,5 @@
 // program version
-#define PROGVERSION                     "1.2.54" // use max 10 chars here!
+#define PROGVERSION                     "1.2.6" // use max 10 chars here!
 #define PROGNAME                        "PAXCNT"
 
 // Verbose enables serial output
@@ -20,7 +20,7 @@
 #define	WIFI_CHANNEL_MAX                13  // total channel number to scan
 #define WIFI_MY_COUNTRY                 "EU"  // for Wifi RF settings
 #define	WIFI_CHANNEL_SWITCH_INTERVAL    50  // [seconds/100] -> 0,5 sec.
-#define WIFI_MAC_FILTER_MASK            0x000000000003 // filter local and group MACs             
+#define WIFI_MAC_FILTER_MASK            0x000000000003 // filter local and group MACs       
 
 // Default LoRa Spreadfactor
 #define LORASFDEFAULT                   9 // 7 ... 12

src/rcommand.cpp

@@ -69,6 +69,7 @@ void set_reset(int val) {
             ESP_LOGI(TAG, "Remote command: reset MAC counter");
             macs.clear(); // clear macs container
             macnum = 0;
+            //salt = rand() % 256; // get new random int between 0 and 255 for salting MAC hashes
             u8x8.clearLine(0); u8x8.clearLine(1); // clear Display counter
             u8x8.clearLine(5);
             u8x8.setCursor(0, 5);

src/wifisniffer.cpp

@@ -73,30 +73,30 @@ void wifi_sniffer_packet_handler(void* buff, wifi_promiscuous_pkt_type_t type) {
 
 		if ( std::find(vendors.begin(), vendors.end(), vendor2int) != vendors.end() ) {
 #endif
-
-//		if ( addr2int & WIFI_MAC_FILTER_MASK == 0) {
 		
-			// log rssi info for scanned MAC
-			ESP_LOGI(TAG, "WiFi RSSI: %02d", ppkt->rx_ctrl.rssi);
+		if (!(addr2int & WIFI_MAC_FILTER_MASK)) { // filter local and group MACs   
 
-			// hash MAC, and if new unique one, store hash in container and increment counter on display
+			// alt and hash MAC, and if new unique one, store hash in container and increment counter on display
+			addr2int <<= 8 || salt; // append salt value to MAC before hashing it
 			itoa(addr2int, macbuf, 10); // convert 64 bit MAC to base 10 decimal string
 			hashedmac = rokkit(macbuf, 10); // hash MAC for privacy, use 10 chars to fit in uint32_t container
 			newmac = macs.insert(hashedmac); // store hashed MAC if new unique
 			
-			if (newmac.second) {
+			if (newmac.second) { // first time seen MAC
 				macnum++; // increment MAC counter
 				itoa(macnum, counter, 10); // base 10 decimal counter value
 				u8x8.draw2x2String(0, 0, counter);
-				ESP_LOGI(TAG, "#%04i: MAC %llx -> Hash %u", macnum, addr2int, hashedmac);
+				ESP_LOGI(TAG, "RSSI %04d -> Hash %010u -> #%04i", ppkt->rx_ctrl.rssi, hashedmac, macnum);
 			}
-//		}
+			else // already seen MAC
+				ESP_LOGI(TAG, "RSSI %04d -> already seen", ppkt->rx_ctrl.rssi);
+		}
 
 #ifdef VENDORFILTER
 		}
 #endif
-	} else {
-		ESP_LOGI(TAG, "Ignoring RSSI %02d (limit: %i)", ppkt->rx_ctrl.rssi, cfg.rssilimit );
-	}
+	} else
+		ESP_LOGI(TAG, "RSSI %04d -> ignoring (limit: %i)", ppkt->rx_ctrl.rssi, cfg.rssilimit);
+
 	yield();
 }