Fixed manifest header boundary checks

Added sanity check against address-space wrap-around

Revert "Added sanity check against address-space wrap-around"

This reverts commit cf81b32.

Author: danielinux

src/libwolfboot.c

@@ -342,8 +342,15 @@ uint16_t wolfBoot_find_header(uint8_t *haystack, uint16_t type, uint8_t **ptr)
 {
     uint8_t *p = haystack;
     uint16_t len;
-    while (((p[0] != 0) || (p[1] != 0)) && ((p - haystack) < IMAGE_HEADER_SIZE)) {
+    const uint8_t *max_p = (haystack - IMAGE_HEADER_OFFSET) + IMAGE_HEADER_SIZE;
+
+    while ((p + 4) < max_p) {
+        if ((p[0] == 0) && (p[1] == 0)) {
+            /* Explicit end of options reached */
+            break;
+        }
         if (*p == HDR_PADDING) {
+            /* Padding byte (skip one position) */
             p++;
             continue;
         }
@@ -353,6 +360,10 @@ uint16_t wolfBoot_find_header(uint8_t *haystack, uint16_t type, uint8_t **ptr)
             continue;
         }
         len = p[2] | (p[3] << 8);
+        if (p + 4 + len > max_p) {
+            /* This field is too large and would overflow the image header */
+            break;
+        }
         if ((p[0] | (p[1] << 8)) == type) {
             *ptr = (p + 4);
             return len;