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
|
/*
File: file_ttf.c
Copyright (C) 2009 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.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "common.h"
#include "filegen.h"
static void register_header_check_ttf(file_stat_t *file_stat);
static int header_check_ttf(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_ttf= {
.extension="ttf",
.description="TrueType Font",
.min_header_distance=0,
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_ttf
};
static const unsigned char header_ttf[5]= {0x00 , 0x01, 0x00, 0x00, 0x00};
static void register_header_check_ttf(file_stat_t *file_stat)
{
register_header_check(0, header_ttf, sizeof(header_ttf), &header_check_ttf, file_stat);
}
/*
* http://www.microsoft.com/typography/otspec/otff.htm
*/
struct ttf_offset_table
{
int32_t sfnt_version;
uint16_t numTables;
uint16_t searchRange;
uint16_t entrySelector;
uint16_t rangeShift;
};
struct ttf_table_directory
{
uint32_t tag;
uint32_t checkSum;
uint32_t offset; /* Offset from beginning of TrueType font file. */
uint32_t length; /* Length of this table. */
};
static unsigned int td_ilog2(unsigned int v)
{
unsigned int l = 0;
while(v >>= 1)
l++;
return l;
}
static int header_check_ttf(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 ttf_offset_table *ttf=(const struct ttf_offset_table *)buffer;
unsigned int numTables;
if(memcmp(buffer, header_ttf, sizeof(header_ttf))!=0)
return 0;
numTables=be16(ttf->numTables);
/* searchRange (Maximum power of 2 <= numTables) x 16.
* entrySelector Log2(maximum power of 2 <= numTables).
* rangeShift NumTables x 16-searchRange.
* */
if(td_ilog2(numTables) != be16(ttf->entrySelector))
return 0;
if((16<<be16(ttf->entrySelector)) != be16(ttf->searchRange))
return 0;
if(numTables * 16 != (unsigned int)be16(ttf->rangeShift)+be16(ttf->searchRange))
return 0;
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_ttf.extension;
if(sizeof(struct ttf_offset_table) + numTables * sizeof(struct ttf_table_directory)
<= buffer_size)
{
const struct ttf_table_directory*ttf_dir=(const struct ttf_table_directory*)(ttf+1);
uint64_t max_offset=0;
unsigned int i;
for(i=0; i<numTables; i++,ttf_dir++)
{
/* | 0x3: align the end of the table */
const uint64_t new_offset=(be32(ttf_dir->offset) + be32(ttf_dir->length))|0x3;
if(max_offset < new_offset)
max_offset=new_offset;
}
file_recovery_new->calculated_file_size=max_offset;
file_recovery_new->data_check=&data_check_size;
file_recovery_new->file_check=&file_check_size;
}
return 1;
}
|
