ota: store component hash as binary array

Component hash is received from the server as a hex string. Convert it to a binary array when decoding the manifest so that it's ready to compare to a locally generated hash. Signed-off-by: Mike Szczys <[email protected]>
golioth · Nov 15, 2024 · 2d14017 · 2d14017
1 parent 7af79bb
commit 2d14017
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Showing 2 changed files with 12 additions and 6 deletions.
diff --git a/include/golioth/ota.h b/include/golioth/ota.h
@@ -22,8 +22,10 @@ extern "C"
 /// https://docs.golioth.io/reference/protocols/coap/ota
 /// @{
 
-/// Size of a SHA256 of Artifact Binary in bytes
-#define GOLIOTH_OTA_COMPONENT_HASH_LEN 64
+/// Size of a SHA256 of Artifact hex string in bytes
+#define GOLIOTH_OTA_COMPONENT_HEX_HASH_LEN 64
+/// Size of a SHA256 of Artifact bin array in bytes
+#define GOLIOTH_OTA_COMPONENT_BIN_HASH_LEN 32
 /// Maximum size of Binary Detected Type in bytes
 #define GOLIOTH_OTA_MAX_COMPONENT_BOOTLOADER_NAME_LEN 7
 /// Maximum size of Relative URI to download binary (+ 7 bytes for Path)
@@ -78,7 +80,7 @@ struct golioth_ota_component
     /// Size of the artifact, in bytes
     int32_t size;
     /// Artifact Hash
-    char hash[GOLIOTH_OTA_COMPONENT_HASH_LEN + 1];
+    uint8_t hash[GOLIOTH_OTA_COMPONENT_BIN_HASH_LEN];
     /// Artifact uri (e.g. "/.u/c/[email protected]")
     char uri[GOLIOTH_OTA_MAX_COMPONENT_URI_LEN + 1];
     /// Artifact bootloader ("mcuboot" or "default"")

diff --git a/src/ota.c b/src/ota.c
@@ -12,6 +12,7 @@
 #include "coap_blockwise.h"
 #include "coap_client.h"
 #include <golioth/golioth_debug.h>
+#include <golioth/golioth_sys.h>
 #include "golioth_util.h"
 #include <golioth/zcbor_utils.h>
 
@@ -216,9 +217,10 @@ static int components_decode(zcbor_state_t *zsd, void *value)
             component->version,
             sizeof(component->version) - 1,
         };
+        char hash_string[GOLIOTH_OTA_COMPONENT_HEX_HASH_LEN + 1];
         struct component_tstr_value hash = {
-            component->hash,
-            sizeof(component->hash) - 1,
+            hash_string,
+            sizeof(hash_string) - 1,
         };
         struct component_tstr_value uri = {
             component->uri,
@@ -248,7 +250,9 @@ static int components_decode(zcbor_state_t *zsd, void *value)
             return err;
         }
 
-        component->size = component_size;
+        component->hash = hex2bin(hash_string, strlen(hash_string), component->hash,
+                sizeof(component->hash));
+        componen->size = component_size;
 
         manifest->num_components++;
     }