bootloader: Don't verify Partition Table as part of Secure Boot

Partition Tables are still signed for backwards compatibility, but signature is no longer checked as
part of bootloader.

Closes https://github.com/espressif/esp-idf/issues/1641

components/bootloader_support/include/esp_flash_partitions.h

@@ -27,7 +27,7 @@
 #define ESP_PARTITION_TABLE_MAX_LEN 0xC00 /* Maximum length of partition table data */
 #define ESP_PARTITION_TABLE_MAX_ENTRIES (ESP_PARTITION_TABLE_MAX_LEN / sizeof(esp_partition_info_t)) /* Maximum length of partition table data, including terminating entry */
 
-/* @brief Verify the partition table (does not include verifying secure boot cryptographic signature)
+/* @brief Verify the partition table
  *
  * @param partition_table Pointer to at least ESP_PARTITION_TABLE_MAX_ENTRIES of potential partition table data. (ESP_PARTITION_TABLE_MAX_LEN bytes.)
  * @param log_errors Log errors if the partition table is invalid.
@@ -35,6 +35,13 @@
  *
  * @return ESP_OK on success, ESP_ERR_INVALID_STATE if partition table is not valid.
  */
-esp_err_t esp_partition_table_basic_verify(const esp_partition_info_t *partition_table, bool log_errors, int *num_partitions);
+esp_err_t esp_partition_table_verify(const esp_partition_info_t *partition_table, bool log_errors, int *num_partitions);
+
+
+/* This function is included for compatibility with the ESP-IDF v3.x API */
+inline static __attribute__((deprecated)) esp_err_t esp_partition_table_basic_verify(const esp_partition_info_t *partition_table, bool log_errors, int *num_partitions)
+{
+    return esp_partition_table_verify(partition_table, log_errors, num_partitions);
+}
 
 #endif

components/bootloader_support/src/bootloader_common.c

@@ -100,18 +100,6 @@ bool bootloader_common_erase_part_type_data(const char *list_erase, bool ota_dat
     int num_partitions;
     bool ret = true;
 
-#ifdef CONFIG_SECURE_BOOT_ENABLED
-    if (esp_secure_boot_enabled()) {
-        ESP_LOGI(TAG, "Verifying partition table signature...");
-        err = esp_secure_boot_verify_signature(ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
-        if (err != ESP_OK) {
-            ESP_LOGE(TAG, "Failed to verify partition table signature.");
-            return false;
-        }
-        ESP_LOGD(TAG, "Partition table signature verified");
-    }
-#endif
-
     partitions = bootloader_mmap(ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
     if (!partitions) {
             ESP_LOGE(TAG, "bootloader_mmap(0x%x, 0x%x) failed", ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
@@ -119,7 +107,7 @@ bool bootloader_common_erase_part_type_data(const char *list_erase, bool ota_dat
     }
     ESP_LOGD(TAG, "mapped partition table 0x%x at 0x%x", ESP_PARTITION_TABLE_OFFSET, (intptr_t)partitions);
 
-    err = esp_partition_table_basic_verify(partitions, true, &num_partitions);
+    err = esp_partition_table_verify(partitions, true, &num_partitions);
     if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to verify partition table");
         ret = false;

components/bootloader_support/src/bootloader_utility.c

@@ -72,18 +72,6 @@ bool bootloader_utility_load_partition_table(bootloader_state_t* bs)
     esp_err_t err;
     int num_partitions;
 
-#ifdef CONFIG_SECURE_BOOT_ENABLED
-    if(esp_secure_boot_enabled()) {
-        ESP_LOGI(TAG, "Verifying partition table signature...");
-        err = esp_secure_boot_verify_signature(ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
-        if (err != ESP_OK) {
-            ESP_LOGE(TAG, "Failed to verify partition table signature.");
-            return false;
-        }
-        ESP_LOGD(TAG, "Partition table signature verified");
-    }
-#endif
-
     partitions = bootloader_mmap(ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
     if (!partitions) {
         ESP_LOGE(TAG, "bootloader_mmap(0x%x, 0x%x) failed", ESP_PARTITION_TABLE_OFFSET, ESP_PARTITION_TABLE_MAX_LEN);
@@ -91,7 +79,7 @@ bool bootloader_utility_load_partition_table(bootloader_state_t* bs)
     }
     ESP_LOGD(TAG, "mapped partition table 0x%x at 0x%x", ESP_PARTITION_TABLE_OFFSET, (intptr_t)partitions);
 
-    err = esp_partition_table_basic_verify(partitions, true, &num_partitions);
+    err = esp_partition_table_verify(partitions, true, &num_partitions);
     if (err != ESP_OK) {
         ESP_LOGE(TAG, "Failed to verify partition table");
         return false;

components/bootloader_support/src/flash_encrypt.c

@@ -254,7 +254,7 @@ static esp_err_t encrypt_and_load_partition_table(esp_partition_info_t *partitio
         ESP_LOGE(TAG, "Failed to read partition table data");
         return err;
     }
-    if (esp_partition_table_basic_verify(partition_table, false, num_partitions) == ESP_OK) {
+    if (esp_partition_table_verify(partition_table, false, num_partitions) == ESP_OK) {
         ESP_LOGD(TAG, "partition table is plaintext. Encrypting...");
         esp_err_t err = esp_flash_encrypt_region(ESP_PARTITION_TABLE_OFFSET,
                                                  FLASH_SECTOR_SIZE);

components/bootloader_support/src/flash_partitions.c

@@ -20,7 +20,7 @@
 
 static const char *TAG = "flash_parts";
 
-esp_err_t esp_partition_table_basic_verify(const esp_partition_info_t *partition_table, bool log_errors, int *num_partitions)
+esp_err_t esp_partition_table_verify(const esp_partition_info_t *partition_table, bool log_errors, int *num_partitions)
 {
     int md5_found = 0;
     int num_parts;