SpejsNode: JSON broker configuration & initial TLS setup

base-firmware/Makefile-user.mk

@@ -1,2 +1,3 @@
 SPIFF_SIZE = 196600
 DISABLE_SPIFFS = 0
+ENABLE_SSL = 1

spejsiot/SpejsNode.cpp

@@ -6,8 +6,15 @@
 
 #define CONFIG_FILE "config.json"
 
+uint8_t hexToInt(char c) {
+    if (c >= '0' && c <= '9') return c - '0';
+    if (c >= 'A' && c <= 'F') return c - 'A' + 10;
+    return c - 'a' + 10;
+}
+
 void SpejsNode::init(bool debug) {
     deviceID = WifiStation.getMAC().substring(6, 12);
+    brokerClient = "iot-" + deviceID;
 
     currentSlot = 0;
     if(!rboot_get_last_boot_rom(&currentSlot)) {
@@ -48,12 +55,18 @@ void SpejsNode::loadJSON(std::vector<EndpointInitializer> initializers) {
 #endif
 
     DynamicJsonBuffer jsonBuffer;
+
     if (fileExist(CONFIG_FILE)) {
         int size = fileGetSize(CONFIG_FILE);
         debugf("Found config file, %d bytes", size);
         char* jsonString = new char[size + 1];
         fileGetContent(CONFIG_FILE, jsonString, size + 1);
+
         JsonObject& root = jsonBuffer.parseObject(jsonString);
+        if (!root.success()) {
+            debugf("invalid config");
+            return;
+        }
 
         if (root.containsKey("name"))
             deviceType = (root["name"]).asString();
@@ -72,6 +85,25 @@ void SpejsNode::loadJSON(std::vector<EndpointInitializer> initializers) {
             }
         }
 
+        // Broker configuration
+        if (root.containsKey("broker")) {
+            auto brokerPort = root.containsKey("brokerPort") ? root["brokerPort"] : 1883;
+            brokerUseTLS = root["brokerUseTLS"];
+            brokerURL = root["broker"].as<String>();
+
+            String hash = root.get<String>("brokerSHA1");
+            if ((hash.length() + 1) % 3 == 0) {
+                int hashLength = (hash.length() + 1) / 3;
+                uint8_t* hashBlob = new uint8_t[hashLength];
+
+                for (int i = 0; i < hashLength; i++) {
+                    hashBlob[i] = hexToInt(hash[3*i]) << 4 | hexToInt(hash[3*i+1]);
+                }
+
+                fingerprints.certSha1 = hashBlob;
+            }
+        }
+
         JsonObject& data = root.get<JsonObject&>("endpoints");
         for (auto it: data) {
             bool found = false;
@@ -164,12 +196,13 @@ void SpejsNode::onConnected() {
     mqtt.setWill(DEV_TOPIC("$online"), "false", 1, true);
 
 #ifdef ENABLE_SSL
-    const uint8_t sha1Fingerprint[] = SSL_FINGERPRINT;
-    mqtt.addSslOptions(SSL_SERVER_VERIFY_LATER);
-    mqtt.setSslFingerprint(sha1Fingerprint, 20);
+    if (brokerUseTLS) {
+        mqtt.addSslOptions(SSL_SERVER_VERIFY_LATER);
+        mqtt.pinCertificate(fingerprints);
+    }
 #endif
 
-    mqtt.connect(brokerURL, "iot-" + deviceID);
+    mqtt.connect(brokerURL, brokerClient);
 
     for(unsigned int i = 0 ; i < endpoints.count() ; i++) {
         endpoints.valueAt(i)->onConnected();

spejsiot/SpejsNode.h

@@ -76,7 +76,14 @@ protected:
     String wifiSSID = WIFI_SSID;
     String wifiPassword = WIFI_PWD;
 
+    String brokerURL = "mqtt://" MQTT_BROKER;
+    String brokerClient;
+
     bool brokerUseTLS = false;
+
+#ifdef ENABLE_SSL
+    SslFingerprints fingerprints;
+#endif
 public:
     MqttClient mqtt;
     HttpServer http;