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PhotoRec: stricter check for .dex

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This commit is contained in:
Christophe Grenier 2014-07-24 23:42:27 +02:00
parent e911b57a11
commit 617179f5d8
1 changed files with 47 additions and 16 deletions
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53
src/file_dex.c
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@ -27,11 +27,12 @@
#include <string.h>
#endif
#include <stdio.h>
#include <ctype.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
static void register_header_check_dex(file_stat_t *file_stat);
static int header_check_dex(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);
const file_hint_t file_hint_dex= {
.extension="dex",
@ -43,23 +44,53 @@ const file_hint_t file_hint_dex= {
.register_header_check=&register_header_check_dex
};
static const unsigned char dex_header[4]= {'d','e','x','\n'};
static void register_header_check_dex(file_stat_t *file_stat)
/* More information can be found at https://source.android.com/devices/tech/dalvik/dex-format.html */
struct dex_header
{
register_header_check(0, dex_header,sizeof(dex_header), &header_check_dex, file_stat);
}
unsigned char magic[8];
uint32_t checksum;
unsigned char signature[20];
uint32_t file_size;
uint32_t header_size;
uint32_t endian_tag;
uint32_t link_size;
uint32_t link_off;
uint32_t map_off;
uint32_t strings_ids_size;
uint32_t strings_ids_off;
uint32_t type_ids_size;
uint32_t type_ids_off;
uint32_t proto_ids_size;
uint32_t proto_ids_off;
uint32_t field_ids_size;
uint32_t field_ids_off;
uint32_t method_ids_size;
uint32_t method_ids_off;
uint32_t class_def_size;
uint32_t class_def_off;
uint32_t data_size;
uint32_t data_off;
} __attribute__ ((__packed__));
static int header_check_dex(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(memcmp(buffer, dex_header, sizeof(dex_header))==0 && buffer[7]==0x00)
{
const struct dex_header *dex=(const struct dex_header*)buffer;
if(!isdigit(buffer[4]) || !isdigit(buffer[5]) || !isdigit(buffer[6]) || buffer[7]!=0x00)
return 0;
if(le32(dex->header_size) < 0x28)
return 0;
if(le32(dex->header_size) >= le32(dex->file_size))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_dex.extension;
file_recovery_new->calculated_file_size=(uint64_t)buffer[0x20]+(((uint64_t)buffer[0x21])<<8)+(((uint64_t)buffer[0x22])<<16)+(((uint64_t)buffer[0x23])<<24);
file_recovery_new->calculated_file_size=le32(dex->file_size);
file_recovery_new->data_check=&data_check_size;
file_recovery_new->file_check=&file_check_size;
return 1;
}
return 0;
}
static void register_header_check_dex(file_stat_t *file_stat)
{
static const unsigned char dex_header[4]= {'d','e','x','\n'};
register_header_check(0, dex_header,sizeof(dex_header), &header_check_dex, file_stat);
}