commit 10ee648145adc508bd09cf1947fe0872d776833c
author Fabio Utzig <utzig@apache.org> Thu Aug 01 12:04:52 2019 -0300
committer Fabio Utzig <utzig@utzig.org> Wed Aug 07 14:33:36 2019 -0300
tree d2292a65add120ab7dc4ec45f73b699c54b45f77
parent b0f0473352c8211e0d7c80e974e58331547db3d7

Update bootutil to reduce amount of global state

The boot loader state currently exists as global variable (boot_data)
which is accessed by all routines; this updates all routines that
require access to the state to receive it by parameter.

Variables that are declared as "static" (globals) were #ifdef'ed to
only use static when building a native bootloader, to avoid stack
allocation. When bootutil is built to run in the simulator they are
stack allocated to avoid thread share.

Signed-off-by: Fabio Utzig <utzig@apache.org>

boot/bootutil/src/encrypted.c

diff --git a/boot/bootutil/src/encrypted.c b/boot/bootutil/src/encrypted.c
index f421f4c..d8f7d6b 100644
--- a/boot/bootutil/src/encrypted.c
+++ b/boot/bootutil/src/encrypted.c
@@ -42,15 +42,12 @@
 #  endif
 #endif
 
-
 #include "bootutil/image.h"
 #include "bootutil/enc_key.h"
 #include "bootutil/sign_key.h"
 
 #include "bootutil_priv.h"
 
-static struct enc_key_data enc_state[BOOT_NUM_SLOTS];
-
 #define TLV_ENC_RSA_SZ  256
 #define TLV_ENC_KW_SZ   24
 
@@ -180,7 +177,7 @@
 #endif
 
 int
-boot_enc_set_key(uint8_t slot, uint8_t *enckey)
+boot_enc_set_key(struct enc_key_data *enc_state, uint8_t slot, uint8_t *enckey)
 {
     int rc;
 
@@ -215,8 +212,9 @@
  * Load encryption key.
  */
 int
-boot_enc_load(int image_index, const struct image_header *hdr,
-        const struct flash_area *fap, uint8_t *enckey)
+boot_enc_load(struct enc_key_data *enc_state, int image_index,
+        const struct image_header *hdr, const struct flash_area *fap,
+        uint8_t *enckey)
 {
 #if defined(MCUBOOT_ENCRYPT_RSA)
     mbedtls_rsa_context rsa;
@@ -307,7 +305,8 @@
 }
 
 bool
-boot_enc_valid(int image_index, const struct flash_area *fap)
+boot_enc_valid(struct enc_key_data *enc_state, int image_index,
+        const struct flash_area *fap)
 {
     int rc;
 
@@ -322,7 +321,7 @@
 }
 
 void
-boot_enc_mark_keys_invalid(void)
+boot_enc_mark_keys_invalid(struct enc_key_data *enc_state)
 {
     size_t slot;
 
@@ -332,8 +331,9 @@
 }
 
 void
-boot_encrypt(int image_index, const struct flash_area *fap, uint32_t off,
-        uint32_t sz, uint32_t blk_off, uint8_t *buf)
+boot_encrypt(struct enc_key_data *enc_state, int image_index,
+        const struct flash_area *fap, uint32_t off, uint32_t sz,
+        uint32_t blk_off, uint8_t *buf)
 {
     struct enc_key_data *enc;
     uint32_t i, j;
@@ -378,9 +378,12 @@
     }
 }
 
-void boot_enc_zeroize(void)
+/**
+ * Clears encrypted state after use.
+ */
+void boot_enc_zeroize(struct enc_key_data *enc_state)
 {
-    memset(&enc_state, 0, sizeof(enc_state));
+    memset(enc_state, 0, sizeof(struct enc_key_data) * BOOT_NUM_SLOTS);
 }
 
 #endif /* MCUBOOT_ENC_IMAGES */