[nrf noup] zephyr: Fix compressed image support

fixup! [nrf noup] zephyr: Add support for compressed image updates

Fixes some issues with compressed image update support

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

boot/bootutil/src/image_validate.c

@@ -508,14 +508,16 @@ bootutil_img_validate(struct enc_key_data *enc_state, int image_index,
                 found_flag = &found_decompressed_sha;
                 break;
             case IMAGE_TLV_DECOMP_SIGNATURE:
-                expected_size = SIG_BUF_SIZE;
                 found_flag = &found_decompressed_signature;
                 break;
             default:
                 continue;
             };
 
-            if (len != expected_size) {
+            if (type == IMAGE_TLV_DECOMP_SIGNATURE && !EXPECTED_SIG_LEN(len)) {
+                rc = -1;
+                goto out;
+            } else if (type != IMAGE_TLV_DECOMP_SIGNATURE && len != expected_size) {
                 rc = -1;
                 goto out;
             }

boot/zephyr/decompression.c

@@ -1027,7 +1027,7 @@ int boot_copy_region_decompress(struct boot_loader_state *state, const struct fl
 
     /* Check if we have unwritten data buffered up and, if so, write it out */
     if (decomp_buf_size > 0) {
-        uint32_t write_padding_size = decomp_buf_size % write_alignment;
+        uint32_t write_padding_size = write_alignment - (decomp_buf_size % write_alignment);
 
         /* Check if additional write padding should be applied to meet the minimum write size */
         if (write_padding_size) {