1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
/*
File: file_abr.c
Copyright (C) 2012,2016 Christophe GRENIER <grenier@cgsecurity.org>
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_abr)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include <assert.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_abr(file_stat_t *file_stat);
struct abr_header
{
char magic[4];
char info[4];
uint32_t size;
} __attribute__ ((gcc_struct, __packed__));
const file_hint_t file_hint_abr= {
.extension="abr",
.description="Adobe Brush",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_abr
};
/*@
@ requires file_recovery->data_check==&data_check_abr;
@ requires valid_data_check_param(buffer, buffer_size, file_recovery);
@ ensures valid_data_check_result(\result, file_recovery);
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_abr(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@ assert file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@ assert file_recovery->file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@
@ loop invariant buffer_size <= 2 * PHOTOREC_MAX_BLOCKSIZE;
@ loop assigns file_recovery->calculated_file_size;
@ loop variant file_recovery->file_size + buffer_size/2 - (file_recovery->calculated_file_size + 12);
@*/
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 12 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert 0 <= i < buffer_size - 12 ; */
const struct abr_header *hdr=(const struct abr_header*)&buffer[i];
/*@ assert \valid_read(hdr); */
if(memcmp(hdr->magic, "8BIM", 4)!=0)
return DC_STOP;
file_recovery->calculated_file_size+=(uint64_t)12 + be32(hdr->size);
}
return DC_CONTINUE;
}
/*@
@ requires buffer_size >= 4 + sizeof(struct abr_header) ;
@ requires separation: \separated(&file_hint_abr, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ ensures valid_header_check_result(\result, file_recovery_new);
@ assigns *file_recovery_new;
@*/
static int header_check_abr(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 struct abr_header *hdr=(const struct abr_header*)&buffer[4];
uint64_t i=4;
assert(buffer_size >= 12);
/*@
@ loop assigns i;
@ loop variant 512 - 12 - i;
@*/
while(i < buffer_size - 12 && i < 512 - 12)
{
const struct abr_header *h=(const struct abr_header*)&buffer[i];
if(memcmp(h->magic, "8BIM", 4)!=0)
return 0;
i+=(uint64_t)12 + be32(h->size);
}
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_abr.extension;
file_recovery_new->min_filesize=(uint64_t)4+12+be32(hdr->size);
file_recovery_new->calculated_file_size=(uint64_t)4+12+be32(hdr->size);
if(file_recovery_new->blocksize < 12)
return 1;
file_recovery_new->data_check=&data_check_abr;
file_recovery_new->file_check=&file_check_size;
return 1;
}
static void register_header_check_abr(file_stat_t *file_stat)
{
static const unsigned char abr_header[11]= {
0x00, 0x02, '8' , 'B' , 'I' , 'M' , 's' , 'a' ,
'm' , 'p' , 0x00
};
register_header_check(2, abr_header, sizeof(abr_header), &header_check_abr, file_stat);
}
#endif
|
