AP_ROMFS: added crc check in ROMFS decompression

libraries/AP_ROMFS/AP_ROMFS.cpp

@@ -18,6 +18,7 @@
 
 #include "AP_ROMFS.h"
 #include "tinf.h"
+#include <AP_Math/crc.h>
 
 #ifdef HAL_HAVE_AP_ROMFS_EMBEDDED_H
 #include <ap_romfs_embedded.h>
@@ -28,11 +29,12 @@ const AP_ROMFS::embedded_file AP_ROMFS::files[] = {};
 /*
   find an embedded file
 */
-const uint8_t *AP_ROMFS::find_file(const char *name, uint32_t &size)
+const uint8_t *AP_ROMFS::find_file(const char *name, uint32_t &size, uint32_t &crc)
 {
     for (uint16_t i=0; i<ARRAY_SIZE(files); i++) {
         if (strcmp(name, files[i].filename) == 0) {
             size = files[i].size;
+            crc = files[i].crc;
             return files[i].contents;
         }
     }
@@ -48,7 +50,8 @@ const uint8_t *AP_ROMFS::find_file(const char *name, uint32_t &size)
 const uint8_t *AP_ROMFS::find_decompress(const char *name, uint32_t &size)
 {
     uint32_t compressed_size = 0;
-    const uint8_t *compressed_data = find_file(name, compressed_size);
+    uint32_t crc;
+    const uint8_t *compressed_data = find_file(name, compressed_size, crc);
     if (!compressed_data) {
         return nullptr;
     }
@@ -101,6 +104,11 @@ const uint8_t *AP_ROMFS::find_decompress(const char *name, uint32_t &size)
         return nullptr;
     }
 
+    if (crc32_small(0, decompressed_data, decompressed_size) != crc) {
+        ::free(decompressed_data);
+        return nullptr;
+    }
+    
     size = decompressed_size;
     return decompressed_data;
 #endif

libraries/AP_ROMFS/AP_ROMFS.h

@@ -25,11 +25,12 @@ public:
 
 private:
     // find an embedded file
-    static const uint8_t *find_file(const char *name, uint32_t &size);
+    static const uint8_t *find_file(const char *name, uint32_t &size, uint32_t &crc);
 
     struct embedded_file {
         const char *filename;
         uint32_t size;
+        uint32_t crc;
         const uint8_t *contents;
     };
     static const struct embedded_file files[];