Merge pull request #28 from hallard/master

MAC, Hash & Salt optimization

src/globals.h

@@ -44,7 +44,7 @@ extern configData_t cfg;
 extern uint8_t mydata[];
 extern uint64_t uptimecounter;
 extern osjob_t sendjob;
-extern int countermode, screensaver, adrmode, lorasf, txpower, rlim, salt;
+extern int countermode, screensaver, adrmode, lorasf, txpower, rlim;
 extern bool joinstate;
 extern std::set<uint16_t> wifis; 
 extern std::set<uint16_t> macs; 

src/macsniff.cpp

@@ -22,20 +22,25 @@ static const char *TAG = "macsniff";
 static wifi_country_t wifi_country = {.cc=WIFI_MY_COUNTRY, .schan=WIFI_CHANNEL_MIN, .nchan=WIFI_CHANNEL_MAX, .policy=WIFI_COUNTRY_POLICY_MANUAL};
 
 uint16_t currentScanDevice = 0;
+uint16_t salt;
+
+uint16_t salt_reset(void) {
+    salt = random(65536); // get new 16bit random for salting hashes
+    return salt;
+}
 
 bool mac_add(uint8_t *paddr, int8_t rssi, bool sniff_type) {
 
     char counter [6]; // uint16_t -> 2 byte -> 5 decimals + '0' terminator -> 6 chars
-    char macbuf [21]; // uint64_t -> 8 byte -> 20 decimals + '0' terminator -> 21 chars
+    char macbuf [17]; // uint64_t -> 8 byte -> 16 hexadecimals + '0' terminator -> 17 chars
     char typebuff[8];
     bool added = false;
-    uint64_t addr2int;
+    uint32_t addr2int;
 	uint32_t vendor2int;
 	uint16_t hashedmac;
-	std::pair<std::set<uint16_t>::iterator, bool> newmac;
 
-    addr2int = ( (uint64_t)paddr[0] ) | ( (uint64_t)paddr[1] << 8 ) | ( (uint64_t)paddr[2] << 16 ) | \
+    // Only last 3 MAC Address bytes are used bay MAC Address Anonymization
-    ( (uint64_t)paddr[3] << 24 ) | ( (uint64_t)paddr[4] << 32 ) | ( (uint64_t)paddr[5] << 40 );
+    addr2int =  ( (uint32_t)paddr[3] ) | ( (uint32_t)paddr[4] << 8 ) | ( (uint32_t)paddr[5] << 16 );
 
     #ifdef VENDORFILTER
         vendor2int = ( (uint32_t)paddr[2] ) | ( (uint32_t)paddr[1] << 8 ) | ( (uint32_t)paddr[0] << 16 );
@@ -46,30 +51,32 @@ bool mac_add(uint8_t *paddr, int8_t rssi, bool sniff_type) {
         // salt and hash MAC, and if new unique one, store identifier in container and increment counter on display
 		// https://en.wikipedia.org/wiki/MAC_Address_Anonymization
 			
-		addr2int |= (uint64_t) salt << 48;		// prepend 16-bit salt to 48-bit MAC
+		addr2int += (uint32_t) salt << 16;		// add 16-bit salt to 24-bit MAC
-		snprintf(macbuf, 21, "%llx", addr2int);	// convert unsigned 64-bit salted MAC to 16 digit hex string
+		snprintf(macbuf, sizeof(macbuf), "%08X", addr2int);	// convert unsigned 32-bit salted MAC to 8 digit hex string
 		hashedmac = rokkit(macbuf, 5);			// hash MAC string, use 5 chars to fit hash in uint16_t container
-		newmac = macs.insert(hashedmac);		// add hashed MAC to total container if new unique
+		auto newmac = macs.insert(hashedmac);	// add hashed MAC to total container if new unique
-        added = newmac.second;                  // true if hashed MAC is unique in container
+        added = newmac.second ? true:false;     // true if hashed MAC is unique in container
 
         if (sniff_type == MAC_SNIFF_WIFI ) {
             rgb_set_color(COLOR_GREEN);
-            newmac = wifis.insert(hashedmac);   // add hashed MAC to wifi container if new unique
+            wifis.insert(hashedmac);   // add hashed MAC to wifi container if new unique
             strcpy(typebuff, "WiFi");
             rgb_set_color(COLOR_NONE);
         } else if (sniff_type == MAC_SNIFF_BLE ) {
             rgb_set_color(COLOR_MAGENTA);
-            newmac = bles.insert(hashedmac);    // add hashed MAC to BLE container if new unique
+            bles.insert(hashedmac);    // add hashed MAC to BLE container if new unique
             strcpy(typebuff, "BLE ");
             rgb_set_color(COLOR_NONE);
         }
      
         if (added) { // first time seen this WIFI or BLE MAC
-            snprintf(counter, 6, "%i", macs.size());	// convert 16-bit MAC counter to decimal counter value
+            snprintf(counter, sizeof(counter), "%d", (uint16_t) macs.size()); // convert 16-bit MAC counter to decimal counter value
             u8x8.draw2x2String(0, 0, counter);          // display number on unique macs total Wifi + BLE
-            ESP_LOGI(TAG, "%s RSSI %04d -> Hash %04x -> counted #%05i", typebuff, rssi, hashedmac, macs.size());
+            ESP_LOGI(TAG, "%s RSSI %ddBi -> Hash %04X -> WiFi:%d  BLE:%d  Tot:%d", 
+                                typebuff, rssi, hashedmac, 
+                                (int) wifis.size(), (int) bles.size(), (int) macs.size());
         } else { // already seen WIFI or BLE MAC
-            ESP_LOGI(TAG, "%s RSSI %04d -> Hash %04x -> already seen", typebuff, rssi, hashedmac);
+            ESP_LOGI(TAG, "%s RSSI %ddBi -> Hash %04X -> already seen", typebuff, rssi, hashedmac);
         }
 
     #ifdef VENDORFILTER
@@ -99,7 +106,6 @@ class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
 
 void BLECount() {
     ESP_LOGI(TAG, "BLE scan started");
-    int blenum = 0; // Total device seen on this scan session
     currentScanDevice = 0; // Set 0 seen device on this scan session
     u8x8.clearLine(3);
     u8x8.drawString(0,3,"BLE Scan...");
@@ -108,11 +114,11 @@ void BLECount() {
     pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
     pBLEScan->setActiveScan(true); //active scan uses more power, but get results faster
     BLEScanResults foundDevices = pBLEScan->start(cfg.blescantime);
-    blenum=foundDevices.getCount();
+    int blenum=foundDevices.getCount();
+    ESP_LOGI(TAG, "BLE scan done, seen %d device(s)", blenum);
     u8x8.clearLine(3);
     u8x8.setCursor(0,3);
-    u8x8.printf("BLE#: %-5i %-3i",bles.size(), blenum);
+    u8x8.printf("BLE#: %-4d  %d", (int) bles.size(), currentScanDevice);
-    ESP_LOGI(TAG, "BLE scan done");
 }
 #endif
 
@@ -142,7 +148,7 @@ void wifi_sniffer_packet_handler(void* buff, wifi_promiscuous_pkt_type_t type) {
         uint8_t *p = (uint8_t *) hdr->addr2;
         mac_add(p, ppkt->rx_ctrl.rssi, MAC_SNIFF_WIFI) ;
     } else {
-        ESP_LOGI(TAG, "WiFi RSSI %04d -> ignoring (limit: %i)", ppkt->rx_ctrl.rssi, cfg.rssilimit);
+        ESP_LOGI(TAG, "WiFi RSSI %d -> ignoring (limit: %d)", ppkt->rx_ctrl.rssi, cfg.rssilimit);
     }
     yield();
 }

src/macsniff.h

@@ -19,6 +19,7 @@ typedef struct {
     uint8_t payload[0]; /* network data ended with 4 bytes csum (CRC32) */
 } wifi_ieee80211_packet_t;
 
+uint16_t salt_reset(void);
 void BLECount();
 void wifi_sniffer_init(void);
 void wifi_sniffer_set_channel(uint8_t channel);

src/main.cpp

@@ -30,6 +30,7 @@ Refer to LICENSE.txt file in repository for more details.
 
 // OLED driver
 #include <U8x8lib.h>
+#include <Wire.h> // Does nothing and avoid any compilation error with I2C
 
 // LMIC-Arduino LoRaWAN Stack
 #include "loraconf.h"
@@ -45,7 +46,7 @@ configData_t cfg; // struct holds current device configuration
 osjob_t sendjob, initjob; // LMIC
 
 // Initialize global variables
-int macnum = 0, salt;
+int macnum = 0;
 uint64_t uptimecounter = 0;
 bool joinstate = false;
 
@@ -270,11 +271,11 @@ void wifi_sniffer_loop(void * pvParameters) {
         wifi_sniffer_set_channel(channel);
         ESP_LOGI(TAG, "Wifi set channel %d", channel);
         u8x8.setCursor(0,5);
-        u8x8.printf(!cfg.rssilimit ? "RLIM:  off" : "RLIM: %4i", cfg.rssilimit);
+        u8x8.printf(!cfg.rssilimit ? "RLIM: off" : "RLIM: %d", cfg.rssilimit);
         u8x8.setCursor(11,5);
         u8x8.printf("ch:%02i", channel);
         u8x8.setCursor(0,4);
-        u8x8.printf("MAC#: %-5i", wifis.size());
+        u8x8.printf("MAC#: %-5d", (int) wifis.size());
 
         // duration of one wifi scan loop reached? then send data and begin new scan cycle
         if( nloop >= ( (100 / cfg.wifichancycle) * (cfg.wifiscancycle * 2)) +1 ) {
@@ -291,8 +292,9 @@ void wifi_sniffer_loop(void * pvParameters) {
                 #ifdef BLECOUNTER
                   bles.clear();                         // clear BLE macs counter
                 #endif 
-                salt = random(65536);                   // get new 16bit random for salting hashes
+                salt_reset(); // get new salt for salting hashes
-                u8x8.clearLine(0); u8x8.clearLine(1);   // clear Display counter    
+                u8x8.clearLine(0); // clear Display counter 
+                u8x8.clearLine(1); 
             }      
 
             // wait until payload is sent, while wifi scanning and mac counting task continues
@@ -475,7 +477,7 @@ void setup() {
     init_display(PROGNAME, PROGVERSION);     
     u8x8.setPowerSave(!cfg.screenon); // set display off if disabled
     u8x8.setCursor(0,5);
-    u8x8.printf(!cfg.rssilimit ? "RLIM: off" : "RLIM: %4i", cfg.rssilimit);
+    u8x8.printf(!cfg.rssilimit ? "RLIM: off" : "RLIM: %d", cfg.rssilimit);
     u8x8.drawString(0,6,"Join Wait       ");
 
 // output LoRaWAN keys to console
@@ -489,7 +491,7 @@ wifi_sniffer_init(); // setup wifi in monitor mode and start MAC counting
 
 // initialize salt value using esp_random() called by random() in arduino-esp32 core
 // note: do this *after* wifi has started, since gets it's seed from RF noise
-salt = random(65536); // get new 16bit random for salting hashes
+salt_reset(); // get new 16bit for salting hashes
  
 // Start FreeRTOS tasks
 #if CONFIG_FREERTOS_UNICORE // run all tasks on core 0 and switch off core 1

src/rcommand.cpp

@@ -70,7 +70,7 @@ void set_reset(int val) {
             macs.clear(); // clear all macs container
             wifis.clear(); // clear Wifi macs container
             bles.clear(); // clear BLE macs container
-            salt = random(65536); // get new 16bit random for salting hashes
+            salt_reset(); // get new 16bit salt
             u8x8.clearLine(0); u8x8.clearLine(1); // clear Display counter
             u8x8.clearLine(5);
             u8x8.setCursor(0, 5);