update: propagate encrypt key read errors

Author: danielinux

src/update_flash.c

@@ -486,8 +486,16 @@ static int RAMFUNCTION wolfBoot_swap_and_final_erase(int resume)
     wolfBoot_printf("In function wolfBoot_final_swap: swapDone = %d\n", swapDone);
     if (swapDone == 0) {
         /* For encrypted images: Get the encryption key and IV */
-        wolfBoot_get_encrypt_key((uint8_t*)tmpBuffer,
-            (uint8_t*)&tmpBuffer[ENCRYPT_KEY_SIZE/sizeof(uint32_t)]);
+        ret = wolfBoot_get_encrypt_key((uint8_t*)tmpBuffer,
+            (uint8_t*)&tmpBuffer[ENCRYPT_KEY_SIZE / sizeof(uint32_t)]);
+        if (ret != 0) {
+#ifdef EXT_FLASH
+            ext_flash_lock();
+#endif
+            hal_flash_lock();
+            wolfBoot_zeroize(tmpBuffer, sizeof(tmpBuffer));
+            return ret;
+        }
         /* Set the magic trailer in the buffer and write it to the staging sector */
         tmpBuffer[TRAILER_OFFSET_WORDS] = WOLFBOOT_MAGIC_TRAIL;
 

tools/unit-tests/unit-update-flash.c

@@ -56,12 +56,15 @@ static int add_payload_type(uint8_t part, uint32_t version, uint32_t size,
     uint16_t img_type);
 
 #ifdef CUSTOM_ENCRYPT_KEY
+static int mock_get_encrypt_key_ret = 0;
 static int mock_set_encrypt_key_ret = 0;
 static int mock_set_encrypt_key_calls = 0;
 
 int wolfBoot_get_encrypt_key(uint8_t *k, uint8_t *nonce)
 {
     int i;
+    if (mock_get_encrypt_key_ret != 0)
+        return mock_get_encrypt_key_ret;
     for (i = 0; i < ENCRYPT_KEY_SIZE; i++) {
         k[i] = (uint8_t)(i + 1);
     }
@@ -138,6 +141,7 @@ static void reset_mock_stats(void)
 {
     wolfBoot_staged_ok = 0;
 #ifdef CUSTOM_ENCRYPT_KEY
+    mock_get_encrypt_key_ret = 0;
     mock_set_encrypt_key_ret = 0;
     mock_set_encrypt_key_calls = 0;
 #endif
@@ -560,6 +564,26 @@ START_TEST (test_final_swap_propagates_encrypt_key_persist_failure)
     cleanup_flash();
 }
 END_TEST
+
+START_TEST (test_final_swap_propagates_encrypt_key_read_failure)
+{
+    int ret;
+
+    reset_mock_stats();
+    prepare_flash();
+
+    add_payload(PART_BOOT, 1, TEST_SIZE_SMALL);
+    add_payload(PART_UPDATE, 2, TEST_SIZE_SMALL);
+
+    mock_get_encrypt_key_ret = -7;
+    ret = wolfBoot_swap_and_final_erase(0);
+
+    ck_assert_int_eq(ret, -7);
+    ck_assert_int_eq(mock_set_encrypt_key_calls, 0);
+
+    cleanup_flash();
+}
+END_TEST
 #endif
 
 START_TEST (test_sunnyday_noupdate)
@@ -1013,6 +1037,7 @@ Suite *wolfboot_suite(void)
 #ifdef UNIT_TEST_FALLBACK_ONLY
 #ifdef EXT_ENCRYPTED
     tcase_add_test(fallback_verify, test_fallback_image_verification_rejects_corruption);
+    tcase_add_test(fallback_verify, test_final_swap_propagates_encrypt_key_read_failure);
     tcase_add_test(fallback_verify, test_final_swap_propagates_encrypt_key_persist_failure);
     suite_add_tcase(s, fallback_verify);
 #endif
@@ -1050,6 +1075,7 @@ Suite *wolfboot_suite(void)
 #endif
 #ifdef EXT_ENCRYPTED
     tcase_add_test(fallback_verify, test_fallback_image_verification_rejects_corruption);
+    tcase_add_test(fallback_verify, test_final_swap_propagates_encrypt_key_read_failure);
     tcase_add_test(fallback_verify, test_final_swap_propagates_encrypt_key_persist_failure);
 #endif