Store thing id in a slot, make serial number 16 bytes

Author: sandeepmistry

examples/MKR1000_Cloud_Blink/MKR1000_Cloud_Blink.ino

@@ -9,8 +9,6 @@ int status = WL_IDLE_STATUS;     // the WiFi radio's status
 
 WiFiClient wifiClient;
 
-const char thingId[] = "blah";
-
 unsigned long getTime() {
   return WiFi.getTime();
 }
@@ -29,7 +27,7 @@ void setup() {
     while (true);
   }
 
-  if (!ArduinoCloud.begin(wifiClient, thingId)) {
+  if (!ArduinoCloud.begin(wifiClient)) {
     Serial.println("Starting Arduino Cloud failed!");
     while (true);
   }

examples/utility/Provisioning/Provisioning.ino

@@ -8,6 +8,7 @@
 const int keySlot            = 0;
 const int compressedCertSlot = 10;
 const int serialNumberSlot   = 11;
+const int thingIdSlot        = 12;
 
 void setup() {
   Serial.begin(9600);
@@ -53,6 +54,7 @@ void setup() {
   Serial.println();
   Serial.println(csr);
 
+  String thingId      = promptAndReadLine("Please enter the thing id: ");
   String issueYear    = promptAndReadLine("Please enter the issue year of the certificate (2000 - 2031): ");
   String issueMonth   = promptAndReadLine("Please enter the issue month of the certificate (1 - 12): ");
   String issueDay     = promptAndReadLine("Please enter the issue day of the certificate (1 - 31): ");
@@ -64,12 +66,19 @@ void setup() {
   serialNumber.toUpperCase();
   signature.toUpperCase();
 
-  byte serialNumberBytes[72];
+  byte thingIdBytes[72];
+  byte serialNumberBytes[16];
   byte signatureBytes[64];
 
+  thingId.getBytes(thingIdBytes, sizeof(thingIdBytes));
   hexStringToBytes(serialNumber, serialNumberBytes, sizeof(serialNumberBytes));
   hexStringToBytes(signature, signatureBytes, 64);
 
+  if (!ECCX08.writeSlot(thingIdSlot, thingIdBytes, sizeof(thingIdBytes))) {
+    Serial.println("Error storing thing id!");
+    while (1);
+  }
+
   if (!ECCX08Cert.beginStorage(compressedCertSlot, serialNumberSlot)) {
     Serial.println("Error starting ECCX08 storage!");
     while (1);

src/ArduinoCloud.cpp

@@ -10,6 +10,7 @@ const static char server[] = "a19g5nbe27wn47.iot.eu-west-1.amazonaws.com"; //"xx
 const static int keySlot            = 0;
 const static int compressedCertSlot = 10;
 const static int serialNumberSlot   = 11;
+const static int thingIdSlot        = 12;
 
 ArduinoCloudClass::ArduinoCloudClass() :
   _bearSslClient(NULL),
@@ -24,12 +25,19 @@ ArduinoCloudClass::~ArduinoCloudClass()
   }
 }
 
-int ArduinoCloudClass::begin(Client& net, const String& id)
+int ArduinoCloudClass::begin(Client& net)
 {
+  byte thingIdBytes[72];
+
   if (!ECCX08.begin()) {
     return 0;
   }
 
+  if (!ECCX08.readSlot(thingIdSlot, thingIdBytes, sizeof(thingIdBytes))) {
+    return 0;
+  }
+  _id = (char*)thingIdBytes;
+
   if (!ECCX08Cert.beginReconstruction(keySlot, compressedCertSlot, serialNumberSlot)) {
     return 0;
   }
@@ -53,8 +61,6 @@ int ArduinoCloudClass::begin(Client& net, const String& id)
   _mqttClient.onMessageAdvanced(ArduinoCloudClass::onMessage);
   _mqttClient.begin(server, 8883, *_bearSslClient);
 
-  _id = id;
-
   _stdoutTopic = "$aws/things/" + _id + "/stdout";
   _stdinTopic = "$aws/things/" + _id + "/stdin";
 

src/ArduinoCloudV2.h

@@ -12,7 +12,7 @@ class ArduinoCloudClass {
   ArduinoCloudClass();
   ~ArduinoCloudClass();
 
-  int begin(Client& net, const String& id);
+  int begin(Client& net);
 
   int connect();
 

src/utility/ECCX08Cert.cpp

@@ -18,6 +18,8 @@ struct __attribute__((__packed__)) CompressedCert {
   byte unused[5];
 };
 
+#define SERIAL_NUMBER_LENGTH 16
+
 static String base64Encode(const byte in[], unsigned int length, const char* prefix, const char* suffix)
 {
   static const char* CODES = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
@@ -255,7 +257,7 @@ void ECCX08CertClass::setExpireYears(int expireYears)
 
 void ECCX08CertClass::setSerialNumber(byte serialNumber[])
 {
-  memcpy(&_temp[72], serialNumber, 72);
+  memcpy(&_temp[72], serialNumber, SERIAL_NUMBER_LENGTH);
 }
 
 int ECCX08CertClass::endStorage()
@@ -264,7 +266,7 @@ int ECCX08CertClass::endStorage()
     return 0;
   }
 
-  if (!ECCX08.writeSlot(_serialNumberSlot, &_temp[72], 72)) {
+  if (!ECCX08.writeSlot(_serialNumberSlot, &_temp[72], SERIAL_NUMBER_LENGTH)) {
     return 0;
   }
 
@@ -296,7 +298,7 @@ int ECCX08CertClass::endReconstruction()
 {
   byte publicKey[64];
   struct CompressedCert compressedCert;
-  byte serialNumber[72];
+  byte serialNumber[SERIAL_NUMBER_LENGTH];
 
   if (!ECCX08.generatePublicKey(_keySlot, publicKey)) {
     return 0;
@@ -575,7 +577,7 @@ int ECCX08CertClass::signatureLength(const byte signature[])
 
 int ECCX08CertClass::serialNumberLength(const byte serialNumber[])
 {
-  int length = 72;
+  int length = SERIAL_NUMBER_LENGTH;
 
   while (*serialNumber == 0 && length) {
     serialNumber++;
@@ -752,7 +754,7 @@ void ECCX08CertClass::appendSignature(const byte signature[], byte out[])
 
 void ECCX08CertClass::appendSerialNumber(const byte serialNumber[], byte out[])
 {
-  int length = 72;
+  int length = SERIAL_NUMBER_LENGTH;
 
   while (*serialNumber == 0 && length) {
     serialNumber++;

src/utility/ECCX08Cert.h

@@ -103,7 +103,7 @@ class ECCX08CertClass {
   String _subjectOrganizationalUnitName;
   String _subjectCommonName;
 
-  byte _temp[144];
+  byte _temp[88];
   byte* _bytes;
   int _length;
 };