Version 1.4

Added simple XOR crypting.

README.md

@@ -4,14 +4,15 @@ A simple library for creating ESP-NOW based Mesh network for ESP8266/ESP32.
 
 ## Features
 
-1. The maximum size of transmitted data is 200 bytes. Currently only unencrypted messages.
+1. The maximum size of transmitted data is 200 bytes.
-2. All nodes are not visible to the network scanner.
+2. Encrypted and unencrypted messages. Simple XOR crypting.
-3. Not required a pre-pairings for data transfer.
+3. All nodes are not visible to the network scanner.
-4. Broadcast or unicast data transmission.
+4. Not required a pre-pairings for data transfer.
-5. There are no periodic/synchronous messages on the network. All devices are in "silent mode" and do not "hum" into the air.
+5. Broadcast or unicast data transmissions.
-6. Each node has its own independent routing table, updated only as needed.
+6. There are no periodic/synchronous messages on the network. All devices are in "silent mode" and do not "hum" into the air.
-7. Each node will receive/send a message if it "sees" at least one device on the network.
+7. Each node has its own independent routing table, updated only as needed.
-8. The number of devices on the network and the area of use is not limited (hypothetically). :-)
+8. Each node will receive/send a message if it "sees" at least one device on the network.
+9. The number of devices on the network and the area of use is not limited (hypothetically). :-)
 
 ## Testing
 
@@ -126,6 +127,14 @@ uint8_t mac[6]
 myNet.stringToMac(string, mac);
 ```
 
+### Sets crypt key
+
+1-20 characters.
+
+```cpp
+myNet.setCryptKey("VERY_LONG_CRYPT_KEY"); 
+```
+
 ### Sets max number of attempts to send message
 
 1-10. 3 default value.
@@ -188,6 +197,7 @@ void setup()
   Serial.begin(115200);
   Serial.println();
   myNet.begin("ZHNetwork");
+  myNet.setCryptKey("VERY_LONG_CRYPT_KEY");
   myNet.setOnBroadcastReceivingCallback(onBroadcastReceiving);
   myNet.setOnUnicastReceivingCallback(onUnicastReceiving);
   myNet.setOnConfirmReceivingCallback(onConfirmReceiving);

examples/Receiver/main.cpp

@@ -10,6 +10,7 @@ void setup()
   Serial.begin(115200);
   Serial.println();
   myNet.begin("ZHNetwork");
+  myNet.setCryptKey("VERY_LONG_CRYPT_KEY");
   myNet.setOnBroadcastReceivingCallback(onBroadcastReceiving);
   myNet.setOnUnicastReceivingCallback(onUnicastReceiving);
   Serial.print("MAC: ");

examples/Transmitter/main.cpp

@@ -13,6 +13,7 @@ void setup()
   Serial.begin(115200);
   Serial.println();
   myNet.begin("ZHNetwork");
+  myNet.setCryptKey("VERY_LONG_CRYPT_KEY");
   myNet.setOnConfirmReceivingCallback(onConfirmReceiving);
   Serial.print("MAC: ");
   Serial.print(myNet.getNodeMac());

library.properties

@@ -1,5 +1,5 @@
 name=ZHNetwork
-version=1.32
+version=1.4
 author=Alexey Zholtikov
 maintainer=Alexey Zholtikov
 sentence=ESP-NOW based Mesh network for ESP8266/ESP32

src/ZHNetwork.cpp

@@ -11,6 +11,7 @@ bool ZHNetwork::sentMessageSemaphore{false};
 bool ZHNetwork::confirmReceivingSemaphore{false};
 bool ZHNetwork::confirmReceiving{false};
 char ZHNetwork::netName_[20]{0};
+char ZHNetwork::key_[20]{0};
 uint8_t ZHNetwork::localMAC[6]{0};
 uint16_t ZHNetwork::lastMessageID[10]{0};
 
@@ -35,7 +36,7 @@ ZHNetwork &ZHNetwork::setOnConfirmReceivingCallback(on_confirm_t onConfirmReceiv
 error_code_t ZHNetwork::begin(const char *netName, const bool gateway)
 {
     randomSeed(analogRead(0));
-    if (strlen(netName) > 1 && strlen(netName) < 20)
+    if (strlen(netName) >= 1 && strlen(netName) <= 20)
         strcpy(netName_, netName);
 #ifdef PRINT_LOG
     Serial.begin(115200);
@@ -192,7 +193,12 @@ void ZHNetwork::maintenance()
             Serial.println(F(" received."));
 #endif
             if (onBroadcastReceivingCallback)
+            {
+                if (key_[0])
+                    for (uint8_t i{0}; i < strlen(incomingData.transmittedData.message); ++i)
+                        incomingData.transmittedData.message[i] = incomingData.transmittedData.message[i] ^ key_[i % strlen(key_)];
                 onBroadcastReceivingCallback(incomingData.transmittedData.message, incomingData.transmittedData.originalSenderMAC);
+            }
             forward = true;
             break;
         case UNICAST:
@@ -208,7 +214,12 @@ void ZHNetwork::maintenance()
             if (macToString(incomingData.transmittedData.originalTargetMAC) == macToString(localMAC))
             {
                 if (onUnicastReceivingCallback)
+                {
+                    if (key_[0])
+                        for (uint8_t i{0}; i < strlen(incomingData.transmittedData.message); ++i)
+                            incomingData.transmittedData.message[i] = incomingData.transmittedData.message[i] ^ key_[i % strlen(key_)];
                     onUnicastReceivingCallback(incomingData.transmittedData.message, incomingData.transmittedData.originalSenderMAC);
+                }
             }
             else
                 unicastMessage(incomingData.transmittedData.message, incomingData.transmittedData.originalTargetMAC, incomingData.transmittedData.originalSenderMAC, UNICAST);
@@ -226,7 +237,12 @@ void ZHNetwork::maintenance()
             if (macToString(incomingData.transmittedData.originalTargetMAC) == macToString(localMAC))
             {
                 if (onUnicastReceivingCallback)
+                {
+                    if (key_[0])
+                        for (uint8_t i{0}; i < strlen(incomingData.transmittedData.message); ++i)
+                            incomingData.transmittedData.message[i] = incomingData.transmittedData.message[i] ^ key_[i % strlen(key_)];
                     onUnicastReceivingCallback(incomingData.transmittedData.message, incomingData.transmittedData.originalSenderMAC);
+                }
                 confirmation_id_t id;
                 memcpy(&id.messageID, &incomingData.transmittedData.messageID, 2);
                 char temp[sizeof(transmitted_data_t::message)];
@@ -405,7 +421,7 @@ void ZHNetwork::maintenance()
         for (uint16_t i{0}; i < confirmationVector.size(); ++i)
         {
             confirmation_waiting_data_t confirmationData = confirmationVector[i];
-            if ((millis() - confirmationData.time) > 1000)
+            if ((millis() - confirmationData.time) > maxTimeForRoutingInfoWaiting_)
             {
                 confirmationVector.erase(confirmationVector.begin() + i);
                 broadcastMessage("", confirmationData.targetMAC, SEARCH_REQUEST);
@@ -448,6 +464,13 @@ uint8_t *ZHNetwork::stringToMac(const String &string, uint8_t *mac)
     return mac;
 }
 
+error_code_t ZHNetwork::setCryptKey(const char *key)
+{
+    if (strlen(key) >= 1 && strlen(key) <= 20)
+        strcpy(key_, key);
+    return SUCCESS;
+}
+
 error_code_t ZHNetwork::setMaxNumberOfAttempts(const uint8_t maxNumberOfAttempts)
 {
     if (maxNumberOfAttempts < 1 || maxNumberOfAttempts > 10)
@@ -551,6 +574,9 @@ uint16_t ZHNetwork::broadcastMessage(const char *data, const uint8_t *target, me
     memcpy(&outgoingData.transmittedData.originalTargetMAC, target, 6);
     memcpy(&outgoingData.transmittedData.originalSenderMAC, &localMAC, 6);
     strcpy(outgoingData.transmittedData.message, data);
+    if (key_[0] && outgoingData.transmittedData.messageType == BROADCAST)
+        for (uint8_t i{0}; i < strlen(outgoingData.transmittedData.message); ++i)
+            outgoingData.transmittedData.message[i] = outgoingData.transmittedData.message[i] ^ key_[i % strlen(key_)];
     memcpy(&outgoingData.intermediateTargetMAC, &broadcastMAC, 6);
     queueForOutgoingData.push(outgoingData);
 #ifdef PRINT_LOG
@@ -586,6 +612,9 @@ uint16_t ZHNetwork::unicastMessage(const char *data, const uint8_t *target, cons
     memcpy(&outgoingData.transmittedData.originalTargetMAC, target, 6);
     memcpy(&outgoingData.transmittedData.originalSenderMAC, sender, 6);
     strcpy(outgoingData.transmittedData.message, data);
+    if (key_[0] && macToString(outgoingData.transmittedData.originalSenderMAC) == macToString(localMAC) && outgoingData.transmittedData.messageType != DELIVERY_CONFIRM_RESPONSE)
+        for (uint8_t i{0}; i < strlen(outgoingData.transmittedData.message); ++i)
+            outgoingData.transmittedData.message[i] = outgoingData.transmittedData.message[i] ^ key_[i % strlen(key_)];
     for (uint16_t i{0}; i < routingVector.size(); ++i)
     {
         routing_table_t routingTable = routingVector[i];

src/ZHNetwork.h

@@ -108,6 +108,7 @@ public:
     static String macToString(const uint8_t *mac);
     uint8_t *stringToMac(const String &string, uint8_t *mac);
 
+    error_code_t setCryptKey(const char *key = "");
     error_code_t setMaxNumberOfAttempts(const uint8_t maxNumberOfAttempts);
     uint8_t getMaxNumberOfAttempts(void);
     error_code_t setMaxWaitingTimeBetweenTransmissions(const uint8_t maxWaitingTimeBetweenTransmissions);
@@ -129,8 +130,9 @@ private:
     static uint8_t localMAC[6];
     static uint16_t lastMessageID[10];
     static char netName_[20];
+    static char key_[20];
 
-    const char *firmware{"1.32"};
+    const char *firmware{"1.4"};
     const uint8_t broadcastMAC[6]{0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
     uint8_t maxNumberOfAttempts_{3};
     uint8_t maxWaitingTimeBetweenTransmissions_{50};