Update more usage of hwGetentropy() (#869)

* Update more usage of hwGetentropy()

* Add hwGetentropy() to Teensy 3.5/3.6

hal/architecture/MyHw.h

@@ -44,12 +44,12 @@ uint8_t hwReadConfig(int adr);
 */
 
 /**
- * @def MY_HW_HAS_GETRANDOM
+ * @def MY_HW_HAS_GETENTROPY
  * @brief Define this, if hwGetentropy is implemented
  *
  * ssize_t hwGetentropy(void *__buffer, size_t __length);
  */
-//#define MY_HW_HAS_GETRANDOM
+//#define MY_HW_HAS_GETENTROPY
 
 /// @brief unique ID
 typedef uint8_t unique_id_t[16];
@@ -141,7 +141,7 @@ void hwDebugPrint(const char *fmt, ... );
  */
 #ifdef DOXYGEN
 #define MY_CRITICAL_SECTION
-#define MY_HW_HAS_GETRANDOM
+#define MY_HW_HAS_GETENTROPY
 #endif  /* DOXYGEN */
 
 #endif // #ifdef MyHw_h

hal/architecture/MyHwESP8266.h

@@ -52,7 +52,7 @@ void hwWriteConfigBlock(void* buf, void* adr, size_t length);
 void hwWriteConfig(const int addr, uint8_t value);
 uint8_t hwReadConfig(const int addr);
 ssize_t hwGetentropy(void *__buffer, size_t __length);
-//#define MY_HW_HAS_GETRANDOM
+//#define MY_HW_HAS_GETENTROPY
 
 /**
  * Restore interrupt state.

hal/architecture/MyHwLinuxGeneric.h

@@ -58,7 +58,7 @@ inline uint8_t hwReadConfig(int addr);
 inline void hwWriteConfig(int addr, uint8_t value);
 inline void hwRandomNumberInit();
 ssize_t hwGetentropy(void *__buffer, size_t __length);
-#define MY_HW_HAS_GETRANDOM
+#define MY_HW_HAS_GETENTROPY
 inline unsigned long hwMillis();
 
 #ifdef MY_RF24_IRQ_PIN

hal/architecture/MyHwNRF5.h

@@ -63,7 +63,7 @@ void hwWriteConfig(int adr, uint8_t value);
 uint8_t hwReadConfig(int adr);
 void hwRandomNumberInit();
 ssize_t hwGetentropy(void *__buffer, size_t __length);
-#define MY_HW_HAS_GETRANDOM
+#define MY_HW_HAS_GETENTROPY
 
 #ifndef MY_SERIALDEVICE
 #define MY_SERIALDEVICE Serial

hal/architecture/MyHwTeensy3.cpp

@@ -132,18 +132,33 @@ uint16_t hwFreeMem()
 	return FUNCTION_NOT_SUPPORTED;
 }
 
-void hwRandomNumberInit(void)
+#if defined(MY_HW_HAS_GETENTROPY)
+ssize_t hwGetentropy(void *__buffer, const size_t __length)
 {
-#if defined(__MK64FX512__) || defined(__MK66FX1M0__)
-	// use HW RNG present on Teensy3.5/3.6
-	// init RNG
 	SIM_SCGC6 |= SIM_SCGC6_RNGA; // enable RNG
 	RNG_CR &= ~RNG_CR_SLP_MASK;
-	RNG_CR |= RNG_CR_HA_MASK;  // high assurance
-	// get random number
-	RNG_CR |= RNG_CR_GO_MASK;
-	while (!(RNG_SR & RNG_SR_OREG_LVL(0xF)));
-	const uint32_t seed = RNG_OR;
+	RNG_CR |= RNG_CR_HA_MASK; //high assurance, not needed
+	size_t pos = 0;
+	while (pos < __length) {
+		RNG_CR |= RNG_CR_GO_MASK;
+		while (!(RNG_SR & RNG_SR_OREG_LVL(0xF)));
+		const uint32_t rndVar = RNG_OR;
+		const uint8_t bsize = (__length - pos) > sizeof(rndVar) ? sizeof(rndVar) : (__length - pos);
+		(void)memcpy((uint8_t*)__buffer + pos, &rndVar, bsize);
+		pos += bsize;
+	}
+	SIM_SCGC6 &= ~SIM_SCGC6_RNGA; // disable RNG
+	return pos;
+}
+#endif
+
+void hwRandomNumberInit(void)
+{
+#if defined(MY_HW_HAS_GETENTROPY)
+	// use HW RNG present on Teensy3.5/3.6
+	// init RNG
+	uint32_t seed = 0;
+	hwGetentropy(&seed, sizeof(seed));
 	randomSeed(seed);
 #else
 	randomSeed(analogRead(MY_SIGNING_SOFT_RANDOMSEED_PIN));
@@ -175,4 +190,4 @@ void hwDebugPrint(const char *fmt, ...)
 #endif
 	va_end(args);
 	MY_SERIALDEVICE.print(fmtBuffer);
-}
+}

hal/architecture/MyHwTeensy3.h

@@ -74,6 +74,10 @@ void hwReboot(void);
 #define MY_SERIALDEVICE Serial
 #endif
 
+#if defined(__MK64FX512__) || defined(__MK66FX1M0__)
+#define MY_HW_HAS_GETENTROPY
+#endif
+
 #define MY_CRITICAL_SECTION ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
 
-#endif
+#endif

hal/architecture/MyMainLinux.cpp

@@ -148,11 +148,7 @@ void generate_soft_sign_hmac_key()
 {
 	uint8_t key[32];
 
-	for (int i = 0; i < 32; i++) {
-		key[i] = random(256) ^ micros();
-		unsigned long enter = hwMillis();
-		while (hwMillis() - enter < (unsigned long)2);
-	}
+	while (hwGetentropy(&key, sizeof(key)) != sizeof(key));
 
 	print_soft_sign_hmac_key(key);
 
@@ -223,11 +219,7 @@ void generate_soft_sign_serial_key()
 {
 	uint8_t key[9];
 
-	for (int i = 0; i < 9; i++) {
-		key[i] = random(256) ^ micros();
-		unsigned long enter = hwMillis();
-		while (hwMillis() - enter < (unsigned long)2);
-	}
+	while (hwGetentropy(&key, sizeof(key)) != sizeof(key));
 
 	print_soft_sign_serial_key(key);
 
@@ -303,11 +295,7 @@ void generate_aes_key()
 {
 	uint8_t key[16];
 
-	for (int i = 0; i < 16; i++) {
-		key[i] = random(256) ^ micros();
-		unsigned long enter = hwMillis();
-		while (hwMillis() - enter < (unsigned long)2);
-	}
+	while (hwGetentropy(&key, sizeof(key)) != sizeof(key));
 
 	print_aes_key(key);