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
|
/*
* zlib_decompress.c - decompress with a zlib wrapper
*
* Originally public domain; changes after 2016-09-07 are copyrighted.
*
* Copyright 2016 Eric Biggers
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include "unaligned.h"
#include "zlib_constants.h"
#include "libdeflate.h"
LIBDEFLATEEXPORT enum libdeflate_result LIBDEFLATEAPI
libdeflate_zlib_decompress_ex(struct libdeflate_decompressor *d,
const void *in, size_t in_nbytes,
void *out, size_t out_nbytes_avail,
size_t *actual_in_nbytes_ret,
size_t *actual_out_nbytes_ret)
{
const u8 *in_next = in;
const u8 * const in_end = in_next + in_nbytes;
u16 hdr;
size_t actual_in_nbytes;
size_t actual_out_nbytes;
enum libdeflate_result result;
if (in_nbytes < ZLIB_MIN_OVERHEAD)
return LIBDEFLATE_BAD_DATA;
/* 2 byte header: CMF and FLG */
hdr = get_unaligned_be16(in_next);
in_next += 2;
/* FCHECK */
if ((hdr % 31) != 0)
return LIBDEFLATE_BAD_DATA;
/* CM */
if (((hdr >> 8) & 0xF) != ZLIB_CM_DEFLATE)
return LIBDEFLATE_BAD_DATA;
/* CINFO */
if ((hdr >> 12) > ZLIB_CINFO_32K_WINDOW)
return LIBDEFLATE_BAD_DATA;
/* FDICT */
if ((hdr >> 5) & 1)
return LIBDEFLATE_BAD_DATA;
/* Compressed data */
result = libdeflate_deflate_decompress_ex(d, in_next,
in_end - ZLIB_FOOTER_SIZE - in_next,
out, out_nbytes_avail,
&actual_in_nbytes, actual_out_nbytes_ret);
if (result != LIBDEFLATE_SUCCESS)
return result;
if (actual_out_nbytes_ret)
actual_out_nbytes = *actual_out_nbytes_ret;
else
actual_out_nbytes = out_nbytes_avail;
in_next += actual_in_nbytes;
/* ADLER32 */
if (libdeflate_adler32(1, out, actual_out_nbytes) !=
get_unaligned_be32(in_next))
return LIBDEFLATE_BAD_DATA;
in_next += 4;
if (actual_in_nbytes_ret)
*actual_in_nbytes_ret = in_next - (u8 *)in;
return LIBDEFLATE_SUCCESS;
}
LIBDEFLATEEXPORT enum libdeflate_result LIBDEFLATEAPI
libdeflate_zlib_decompress(struct libdeflate_decompressor *d,
const void *in, size_t in_nbytes,
void *out, size_t out_nbytes_avail,
size_t *actual_out_nbytes_ret)
{
return libdeflate_zlib_decompress_ex(d, in, in_nbytes,
out, out_nbytes_avail,
NULL, actual_out_nbytes_ret);
}
|
