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
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
|
/*
File: file_axx.c
Copyright (C) 2012 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_axx)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
#include "common.h"
#include "log.h"
/*@ requires valid_register_header_check(file_stat); */
static void register_header_check_axx(file_stat_t *file_stat);
const file_hint_t file_hint_axx= {
.extension="axx",
.description="AxCrypt",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_axx
};
struct SHeader
{
uint32_t aoLength;
uint8_t oType;
} __attribute__ ((gcc_struct, __packed__));
/*@
@ requires fr->file_check == &file_check_axx;
@ requires valid_file_check_param(fr);
@ ensures valid_file_check_result(fr);
@ assigns *fr->handle, errno, fr->file_size;
@ assigns Frama_C_entropy_source;
@*/
static void file_check_axx(file_recovery_t *fr)
{
uint64_t offset=0x10;
/*@
@ loop assigns *fr->handle, errno, fr->file_size;
@ loop assigns offset, Frama_C_entropy_source;
@ loop variant 0x8000000000000000 - offset;
@ */
while(offset < 0x8000000000000000)
{
char buffer[sizeof(struct SHeader)];
const struct SHeader *header=(const struct SHeader *)&buffer;
unsigned int len;
if(my_fseek(fr->handle, offset, SEEK_SET) < 0)
return ;
if (fread(&buffer, sizeof(buffer), 1, fr->handle)!=1)
return ;
#if defined(__FRAMAC__)
Frama_C_make_unknown(&buffer, sizeof(buffer));
#endif
len=le32(header->aoLength);
#ifdef DEBUG_AAX
log_info("axx 0x%llx 0x%x 0x%x/%d\n", (long long int)offset, len, header->oType, header->oType);
#endif
if(len<5)
return ;
offset+=len;
if(offset >= 0x8000000000000000)
break;
if(header->oType==63) // eData
{
char buf[sizeof(uint64_t)];
const uint64_t *fsize_ptr=(const uint64_t *)&buf;
uint64_t fsize;
if(len!=13)
return ;
if (fread(&buf, sizeof(buf), 1, fr->handle)!=1)
return ;
#if defined(__FRAMAC__)
Frama_C_make_unknown(&buf, sizeof(buf));
#endif
fsize=le64(*fsize_ptr);
if(fsize >= 0x8000000000000000)
break;
offset+=fsize;
fr->file_size=(fr->file_size < offset ? 0 : offset);
return ;
}
}
fr->file_size=0;
}
/*@
@ requires buffer_size > 0x25+sizeof(struct SHeader);
@ requires separation: \separated(&file_hint_axx, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@ assigns *file_recovery_new;
@*/
static int header_check_axx(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 SHeader *header=(const struct SHeader *)&buffer[0x10+0x15];
if(le32(header->aoLength) < 5)
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_axx.extension;
file_recovery_new->file_check=&file_check_axx;
file_recovery_new->min_filesize=(uint64_t)0x25+le32(header->aoLength);
return 1;
}
static void register_header_check_axx(file_stat_t *file_stat)
{
// guidAxCryptFileIdInverse (32 bytes) + length (4) + ePreamble=2
static const unsigned char axx_header[0x15]= {
0xc0, 0xb9, 0x07, 0x2e, 0x4f, 0x93, 0xf1, 0x46,
0xa0, 0x15, 0x79, 0x2c, 0xa1, 0xd9, 0xe8, 0x21,
0x15, 0x00, 0x00, 0x00, 0x02
};
register_header_check(0, axx_header, sizeof(axx_header), &header_check_axx, file_stat);
}
#endif
|