From 62be5e5ed16461d58f9d8dc3d8ac07743a44e1dd Mon Sep 17 00:00:00 2001
From: Christophe Grenier <grenier@cgsecurity.org>
Date: Mon, 15 Mar 2021 19:08:34 +0100
Subject: [PATCH] src/file_z2d.c: add Frama-C annotations

---
 src/file_z2d.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/src/file_z2d.c b/src/file_z2d.c
index 5d5557f7..1f6b6c96 100644
--- a/src/file_z2d.c
+++ b/src/file_z2d.c
@@ -31,29 +31,34 @@
 #include "types.h"
 #include "filegen.h"
 
+/*@ requires \valid(file_stat); */
 static void register_header_check_z2d(file_stat_t *file_stat);
 
-const file_hint_t file_hint_z2d= {
-  .extension="z2d",
-  .description="ZeroCad",
-  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
-  .recover=1,
-  .enable_by_default=1,
-  .register_header_check=&register_header_check_z2d
+const file_hint_t file_hint_z2d = {
+  .extension = "z2d",
+  .description = "ZeroCad",
+  .max_filesize = PHOTOREC_MAX_FILE_SIZE,
+  .recover = 1,
+  .enable_by_default = 1,
+  .register_header_check = &register_header_check_z2d
 };
 
-static const unsigned char z2d_header[2]=  { 0xc3, 0x40 };
-
+/*@
+  @ requires buffer_size >= 0x4a;
+  @ requires \valid_read(buffer+(0..buffer_size-1));
+  @ requires valid_file_recovery(file_recovery);
+  @ requires \valid(file_recovery_new);
+  @ requires file_recovery_new->blocksize > 0;
+  @ requires separation: \separated(&file_hint_z2d, buffer+(..), file_recovery, file_recovery_new);
+  @ ensures  \result!=0 ==> valid_file_recovery(file_recovery_new);
+  @ assigns  *file_recovery_new;
+  @*/
 static int header_check_z2d(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
 {
-  if(buffer[0x28]==0xc3 && buffer[0x29]==0x40 &&
-      buffer[0x30]==0xc3 && buffer[0x31]==0x40 &&
-      buffer[0x38]==0xbf && buffer[0x39]==0x40 &&
-      buffer[0x40]==0xbf && buffer[0x41]==0x40 &&
-      buffer[0x48]==0xb7 && buffer[0x49]==0x40)
+  if(buffer[0x28] == 0xc3 && buffer[0x29] == 0x40 && buffer[0x30] == 0xc3 && buffer[0x31] == 0x40 && buffer[0x38] == 0xbf && buffer[0x39] == 0x40 && buffer[0x40] == 0xbf && buffer[0x41] == 0x40 && buffer[0x48] == 0xb7 && buffer[0x49] == 0x40)
   {
     reset_file_recovery(file_recovery_new);
-    file_recovery_new->extension=file_hint_z2d.extension;
+    file_recovery_new->extension = file_hint_z2d.extension;
     return 1;
   }
   return 0;
@@ -61,6 +66,7 @@ static int header_check_z2d(const unsigned char *buffer, const unsigned int buff
 
 static void register_header_check_z2d(file_stat_t *file_stat)
 {
+  static const unsigned char z2d_header[2] = { 0xc3, 0x40 };
   register_header_check(0x28, z2d_header, sizeof(z2d_header), &header_check_z2d, file_stat);
 }
 #endif