Move SHA256 code into OTA files

Author: pennam

src/ArduinoIoTCloudTCP.cpp

@@ -23,6 +23,7 @@
 
 #ifdef HAS_TCP
 #include <ArduinoIoTCloudTCP.h>
+
 #ifdef BOARD_HAS_ECCX08
   #include "tls/BearSSLTrustAnchors.h"
   #include "tls/utility/CryptoUtil.h"
@@ -34,45 +35,18 @@
 #endif
 
 #ifdef BOARD_HAS_OFFLOADED_ECCX08
-#include <ArduinoECCX08.h>
-#include "tls/utility/CryptoUtil.h"
-#endif
-
-#ifdef BOARD_STM32H7
-#  include "tls/utility/SHA256.h"
-#  include <stm32h7xx_hal_rtc_ex.h>
-#  include <WiFi.h>
-#endif
-
-#if defined (ARDUINO_ARCH_ESP32) && OTA_ENABLED
-#  include "tls/utility/SHA256.h"
-#include "esp_spi_flash.h"
-#include "esp_ota_ops.h"
-#include "esp_image_format.h"
-#endif
-
-#if defined (ARDUINO_NANO_RP2040_CONNECT) || \
-   (defined (ARDUINO_ARCH_SAMD) && OTA_ENABLED)
-#include "utility/ota/FlashSHA256.h"
+  #include <ArduinoECCX08.h>
+  #include "tls/utility/CryptoUtil.h"
 #endif
 
 #if OTA_ENABLED
-#include "utility/ota/OTA.h"
+  #include "utility/ota/OTA.h"
 #endif
 
 #include <algorithm>
 #include "cbor/CBOREncoder.h"
-
 #include "utility/watchdog/Watchdog.h"
 
-/******************************************************************************
- * EXTERN
- ******************************************************************************/
-
-#ifdef BOARD_STM32H7
-extern RTC_HandleTypeDef RTCHandle;
-#endif
-
 /******************************************************************************
    LOCAL MODULE FUNCTIONS
  ******************************************************************************/
@@ -164,100 +138,8 @@ int ArduinoIoTCloudTCP::begin(bool const enable_watchdog, String brokerAddress,
 #endif /* AVR */
 
 #if OTA_ENABLED && !defined(__AVR__)
-#if defined(BOARD_STM32H7)
-  /* The length of the application can be retrieved the same way it was
-   * communicated to the bootloader, that is by writing to the non-volatile
-   * storage registers of the RTC.
-   */
-  SHA256         sha256;
-  uint32_t const app_start = 0x8040000;
-  uint32_t const app_size  = HAL_RTCEx_BKUPRead(&RTCHandle, RTC_BKP_DR3);
-
-  sha256.begin();
-  uint32_t b = 0;
-  uint32_t bytes_read = 0; for(uint32_t a = app_start;
-                               bytes_read < app_size;
-                               bytes_read += sizeof(b), a += sizeof(b))
-  {
-    /* Read the next chunk of memory. */
-    memcpy(&b, reinterpret_cast<const void *>(a), sizeof(b));
-    /* Feed it to SHA256. */
-    sha256.update(reinterpret_cast<uint8_t *>(&b), sizeof(b));
-  }
-  /* Retrieve the final hash string. */
-  uint8_t sha256_hash[SHA256::HASH_SIZE] = {0};
-  sha256.finalize(sha256_hash);
-  String sha256_str;
-  std::for_each(sha256_hash,
-                sha256_hash + SHA256::HASH_SIZE,
-                [&sha256_str](uint8_t const elem)
-                {
-                  char buf[4];
-                  snprintf(buf, 4, "%02X", elem);
-                  sha256_str += buf;
-                });
-  DEBUG_VERBOSE("SHA256: %d bytes (of %d) read", bytes_read, app_size);
-#elif defined(ARDUINO_ARCH_SAMD)
-  /* Calculate the SHA256 checksum over the firmware stored in the flash of the
-   * MCU. Note: As we don't know the length per-se we read chunks of the flash
-   * until we detect one containing only 0xFF (= flash erased). This only works
-   * for firmware updated via OTA and second stage bootloaders (SxU family)
-   * because only those erase the complete flash before performing an update.
-   * Since the SHA256 firmware image is only required for the cloud servers to
-   * perform a version check after the OTA update this is a acceptable trade off.
-   * The bootloader is excluded from the calculation and occupies flash address
-   * range 0 to 0x2000, total flash size of 0x40000 bytes (256 kByte).
-   */
-  String const sha256_str = FlashSHA256::calc(0x2000, 0x40000 - 0x2000);
-#elif defined(ARDUINO_NANO_RP2040_CONNECT)
-  /* The maximum size of a RP2040 OTA update image is 1 MByte (that is 1024 *
-   * 1024 bytes or 0x100'000 bytes).
-   */
-  String const sha256_str = FlashSHA256::calc(XIP_BASE, 0x100000);
-#elif defined(ARDUINO_ARCH_ESP32)
-  SHA256         sha256;
-
-  uint32_t lengthLeft = ESP.getSketchSize();
-
-  const esp_partition_t *running = esp_ota_get_running_partition();
-  if (!running) {
-    DEBUG_ERROR("Partition could not be found");
-  }
-  const size_t bufSize = SPI_FLASH_SEC_SIZE;
-  std::unique_ptr<uint8_t[]> buf(new uint8_t[bufSize]);
-  uint32_t offset = 0;
-  if(!buf.get()) {
-    DEBUG_ERROR("Not enough memory to allocate buffer");
-  }
-
-  sha256.begin();
-  while( lengthLeft > 0) {
-    size_t readBytes = (lengthLeft < bufSize) ? lengthLeft : bufSize;
-    if (!ESP.flashRead(running->address + offset, reinterpret_cast<uint32_t*>(buf.get()), (readBytes + 3) & ~3)) {
-      DEBUG_ERROR("Could not read buffer from flash");
-    }
-    sha256.update(buf.get(), readBytes);
-    lengthLeft -= readBytes;
-    offset += readBytes;
-  }
-  /* Retrieve the final hash string. */
-  uint8_t sha256_hash[SHA256::HASH_SIZE] = {0};
-  sha256.finalize(sha256_hash);
-  String sha256_str;
-  std::for_each(sha256_hash,
-                sha256_hash + SHA256::HASH_SIZE,
-                [&sha256_str](uint8_t const elem)
-                {
-                  char buf[4];
-                  snprintf(buf, 4, "%02X", elem);
-                  sha256_str += buf;
-                });
-  DEBUG_VERBOSE("SHA256: %d bytes (of %d) read", ESP.getSketchSize() - lengthLeft, ESP.getSketchSize());
-#else
-# error "No method for SHA256 checksum calculation over application image defined for this architecture."
-#endif
-  DEBUG_VERBOSE("SHA256: HASH(%d) = %s", strlen(sha256_str.c_str()), sha256_str.c_str());
-  _ota_img_sha256 = sha256_str;
+  _ota_img_sha256 = getOTAImageSHA256();
+  DEBUG_VERBOSE("SHA256: HASH(%d) = %s", strlen(_ota_img_sha256.c_str()), _ota_img_sha256.c_str());
 #endif /* OTA_ENABLED */
 
 #if defined(BOARD_HAS_ECCX08) || defined(BOARD_HAS_OFFLOADED_ECCX08) || defined(BOARD_HAS_SE050)
@@ -902,6 +784,21 @@ void ArduinoIoTCloudTCP::onOTARequest()
   _ota_error = esp32_onOTARequest(_ota_url.c_str());
 #endif
 }
+
+String ArduinoIoTCloudTCP::getOTAImageSHA256()
+{
+#if defined (ARDUINO_ARCH_SAMD)
+  return samd_getOTAImageSHA256();
+#elif defined (ARDUINO_NANO_RP2040_CONNECT)
+  return rp2040_connect_getOTAImageSHA256();
+#elif defined (BOARD_STM32H7)
+  return portenta_h7_getOTAImageSHA256();
+#elif defined (ARDUINO_ARCH_ESP32)
+  return esp32_getOTAImageSHA256();
+#else
+  # error "No method for SHA256 checksum calculation over application image defined for this architecture."
+#endif
+}
 #endif
 
 void ArduinoIoTCloudTCP::updateThingTopics()

src/ArduinoIoTCloudTCP.h

@@ -202,6 +202,7 @@ class ArduinoIoTCloudTCP: public ArduinoIoTCloudClass
 
 #if OTA_ENABLED
     void onOTARequest();
+    String getOTAImageSHA256();
     void sendDevicePropertyToCloud(String const name);
 #endif
 

src/utility/ota/OTA-esp32.cpp

@@ -22,9 +22,13 @@
 #include <AIoTC_Config.h>
 
 #if defined ARDUINO_ARCH_ESP32 && OTA_ENABLED
+
 #include "OTA.h"
 #include <Arduino_DebugUtils.h>
-#include <Arduino_ESP_OTA.h>
+#include <Arduino_ESP32_OTA.h>
+#include "tls/utility/SHA256.h"
+
+#include <esp_ota_ops.h>
 
 /******************************************************************************
  * FUNCTION DEFINITION
@@ -64,4 +68,47 @@ int esp32_onOTARequest(char const * ota_url)
   return static_cast<int>(OTAError::None);
 }
 
+String esp32_getOTAImageSHA256()
+{
+  SHA256         sha256;
+
+  uint32_t lengthLeft = ESP.getSketchSize();
+
+  const esp_partition_t *running = esp_ota_get_running_partition();
+  if (!running) {
+    DEBUG_ERROR("Partition could not be found");
+  }
+  const size_t bufSize = SPI_FLASH_SEC_SIZE;
+  std::unique_ptr<uint8_t[]> buf(new uint8_t[bufSize]);
+  uint32_t offset = 0;
+  if(!buf.get()) {
+    DEBUG_ERROR("Not enough memory to allocate buffer");
+  }
+
+  sha256.begin();
+  while( lengthLeft > 0) {
+    size_t readBytes = (lengthLeft < bufSize) ? lengthLeft : bufSize;
+    if (!ESP.flashRead(running->address + offset, reinterpret_cast<uint32_t*>(buf.get()), (readBytes + 3) & ~3)) {
+      DEBUG_ERROR("Could not read buffer from flash");
+    }
+    sha256.update(buf.get(), readBytes);
+    lengthLeft -= readBytes;
+    offset += readBytes;
+  }
+  /* Retrieve the final hash string. */
+  uint8_t sha256_hash[SHA256::HASH_SIZE] = {0};
+  sha256.finalize(sha256_hash);
+  String sha256_str;
+  std::for_each(sha256_hash,
+                sha256_hash + SHA256::HASH_SIZE,
+                [&sha256_str](uint8_t const elem)
+                {
+                  char buf[4];
+                  snprintf(buf, 4, "%02X", elem);
+                  sha256_str += buf;
+                });
+  DEBUG_VERBOSE("SHA256: %d bytes (of %d) read", ESP.getSketchSize() - lengthLeft, ESP.getSketchSize());
+  return sha256_str;
+}
+
 #endif /* ARDUINO_ARCH_ESP32 */

src/utility/ota/OTA-nano-rp2040.cpp

@@ -32,6 +32,7 @@
 #include "mbed.h"
 #include "FATFileSystem.h"
 #include "FlashIAPBlockDevice.h"
+#include "utility/ota/FlashSHA256.h"
 
 /******************************************************************************
  * FUNCTION DEFINITION
@@ -249,4 +250,12 @@ int rp2040_connect_onOTARequest(char const * ota_url)
   return static_cast<int>(OTAError::None);
 }
 
+String rp2040_connect_getOTAImageSHA256()
+{
+  /* The maximum size of a RP2040 OTA update image is 1 MByte (that is 1024 *
+   * 1024 bytes or 0x100'000 bytes).
+   */
+  return FlashSHA256::calc(XIP_BASE, 0x100000);
+}
+
 #endif /* ARDUINO_NANO_RP2040_CONNECT */

src/utility/ota/OTA-portenta-h7.cpp

@@ -29,8 +29,18 @@
 #include <Arduino_Portenta_OTA.h>
 #include <Arduino_ConnectionHandler.h>
 
+#include <stm32h7xx_hal_rtc_ex.h>
+
+#include "tls/utility/SHA256.h"
+
 #include "../watchdog/Watchdog.h"
 
+/******************************************************************************
+ * EXTERN
+ ******************************************************************************/
+
+extern RTC_HandleTypeDef RTCHandle;
+
 /******************************************************************************
  * FUNCTION DEFINITION
  ******************************************************************************/
@@ -96,4 +106,41 @@ int portenta_h7_onOTARequest(char const * ota_url, const bool use_ethernet)
   NVIC_SystemReset();
 }
 
+String portenta_h7_getOTAImageSHA256()
+{
+  /* The length of the application can be retrieved the same way it was
+   * communicated to the bootloader, that is by writing to the non-volatile
+   * storage registers of the RTC.
+   */
+  SHA256         sha256;
+  uint32_t const app_start = 0x8040000;
+  uint32_t const app_size  = HAL_RTCEx_BKUPRead(&RTCHandle, RTC_BKP_DR3);
+
+  sha256.begin();
+  uint32_t b = 0;
+  uint32_t bytes_read = 0; for(uint32_t a = app_start;
+                               bytes_read < app_size;
+                               bytes_read += sizeof(b), a += sizeof(b))
+  {
+    /* Read the next chunk of memory. */
+    memcpy(&b, reinterpret_cast<const void *>(a), sizeof(b));
+    /* Feed it to SHA256. */
+    sha256.update(reinterpret_cast<uint8_t *>(&b), sizeof(b));
+  }
+  /* Retrieve the final hash string. */
+  uint8_t sha256_hash[SHA256::HASH_SIZE] = {0};
+  sha256.finalize(sha256_hash);
+  String sha256_str;
+  std::for_each(sha256_hash,
+                sha256_hash + SHA256::HASH_SIZE,
+                [&sha256_str](uint8_t const elem)
+                {
+                  char buf[4];
+                  snprintf(buf, 4, "%02X", elem);
+                  sha256_str += buf;
+                });
+  DEBUG_VERBOSE("SHA256: %d bytes (of %d) read", bytes_read, app_size);
+  return sha256_str;
+}
+
 #endif /* BOARD_STM32H7 */

src/utility/ota/OTA-samd.cpp

@@ -15,17 +15,18 @@
    a commercial license, send an email to [email protected].
 */
 
-#ifdef ARDUINO_ARCH_SAMD
-
 /******************************************************************************
  * INCLUDE
  ******************************************************************************/
 
-#include "OTA.h"
+#include <AIoTC_Config.h>
 
-#include <Arduino_DebugUtils.h>
+#if defined (ARDUINO_ARCH_SAMD) && OTA_ENABLED
 
+#include "OTA.h"
+#include <Arduino_DebugUtils.h>
 #include "../watchdog/Watchdog.h"
+#include "utility/ota/FlashSHA256.h"
 
 #if OTA_STORAGE_SNU
 #  include <SNU.h>
@@ -65,4 +66,19 @@ int samd_onOTARequest(char const * ota_url)
   return static_cast<int>(OTAError::DownloadFailed);
 }
 
+String samd_getOTAImageSHA256()
+{
+  /* Calculate the SHA256 checksum over the firmware stored in the flash of the
+   * MCU. Note: As we don't know the length per-se we read chunks of the flash
+   * until we detect one containing only 0xFF (= flash erased). This only works
+   * for firmware updated via OTA and second stage bootloaders (SxU family)
+   * because only those erase the complete flash before performing an update.
+   * Since the SHA256 firmware image is only required for the cloud servers to
+   * perform a version check after the OTA update this is a acceptable trade off.
+   * The bootloader is excluded from the calculation and occupies flash address
+   * range 0 to 0x2000, total flash size of 0x40000 bytes (256 kByte).
+   */
+  return FlashSHA256::calc(0x2000, 0x40000 - 0x2000);
+}
+
 #endif /* ARDUINO_ARCH_SAMD */