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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* unzip.c -- decompress files in gzip or pkzip format.
* Copyright (C) 1992-1993 Jean-loup Gailly
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License, see the file COPYING.
*
* The code in this file is derived from the file funzip.c written
* and put in the public domain by Mark Adler.
*/
/*
This version can extract files in gzip or pkzip format.
For the latter, only the first entry is extracted, and it has to be
either deflated or stored.
*/
#ifdef RCSID
static char rcsid[] = "$Id$";
#endif
#include "tailor.h"
#include "gzip.h"
#include "crypt.h"
/* PKZIP header definitions */
#define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
#define LOCFLG 6 /* offset of bit flag */
#define CRPFLG 1 /* bit for encrypted entry */
#define EXTFLG 8 /* bit for extended local header */
#define LOCHOW 8 /* offset of compression method */
#define LOCTIM 10 /* file mod time (for decryption) */
#define LOCCRC 14 /* offset of crc */
#define LOCSIZ 18 /* offset of compressed size */
#define LOCLEN 22 /* offset of uncompressed length */
#define LOCFIL 26 /* offset of file name field length */
#define LOCEXT 28 /* offset of extra field length */
#define LOCHDR 30 /* size of local header, including sig */
#define EXTHDR 16 /* size of extended local header, inc sig */
/* Globals */
int decrypt; /* flag to turn on decryption */
char *key; /* not used--needed to link crypt.c */
int pkzip = 0; /* set for a pkzip file */
int ext_header = 0; /* set if extended local header */
/* ===========================================================================
* Check zip file and advance inptr to the start of the compressed data.
* Get ofname from the local header if necessary.
*/
int check_zipfile(in)
int in; /* input file descriptors */
{
uch *h = inbuf + inptr; /* first local header */
ifd = in;
/* Check validity of local header, and skip name and extra fields */
inptr += LOCHDR + SH(h + LOCFIL) + SH(h + LOCEXT);
if (inptr > insize || LG(h) != LOCSIG) {
fprintf(stderr, "\n%s: %s: not a valid zip file\n",
progname, ifname);
exit_code = ERROR;
return ERROR;
}
method = h[LOCHOW];
if (method != STORED && method != DEFLATED) {
fprintf(stderr,
"\n%s: %s: first entry not deflated or stored -- use unzip\n",
progname, ifname);
exit_code = ERROR;
return ERROR;
}
/* If entry encrypted, decrypt and validate encryption header */
if ((decrypt = h[LOCFLG] & CRPFLG) != 0) {
fprintf(stderr, "\n%s: %s: encrypted file -- use unzip\n",
progname, ifname);
exit_code = ERROR;
return ERROR;
}
/* Save flags for unzip() */
ext_header = (h[LOCFLG] & EXTFLG) != 0;
pkzip = 1;
/* Get ofname and time stamp from local header (to be done) */
return OK;
}
/* ===========================================================================
* Unzip in to out. This routine works on both gzip and pkzip files.
*
* IN assertions: the buffer inbuf contains already the beginning of
* the compressed data, from offsets inptr to insize-1 included.
* The magic header has already been checked. The output buffer is cleared.
*/
int unzip(in, out)
int in, out; /* input and output file descriptors */
{
ulg orig_crc = 0; /* original crc */
ulg orig_len = 0; /* original uncompressed length */
int n;
uch buf[EXTHDR]; /* extended local header */
ifd = in;
ofd = out;
updcrc(NULL, 0); /* initialize crc */
if (pkzip && !ext_header) { /* crc and length at the end otherwise */
orig_crc = LG(inbuf + LOCCRC);
orig_len = LG(inbuf + LOCLEN);
}
/* Decompress */
if (method == DEFLATED) {
int res = inflate();
if (res == 3) {
error("out of memory");
} else if (res != 0) {
error("invalid compressed data--format violated");
}
} else if (pkzip && method == STORED) {
register ulg n = LG(inbuf + LOCLEN);
if (n != LG(inbuf + LOCSIZ) - (decrypt ? RAND_HEAD_LEN : 0)) {
fprintf(stderr, "len %ld, siz %ld\n", n, LG(inbuf + LOCSIZ));
error("invalid compressed data--length mismatch");
}
while (n--) {
uch c = (uch)get_byte();
#ifdef CRYPT
if (decrypt) zdecode(c);
#endif
put_ubyte(c);
}
flush_window();
} else {
error("internal error, invalid method");
}
/* Get the crc and original length */
if (!pkzip) {
/* crc32 (see algorithm.doc)
* uncompressed input size modulo 2^32
*/
for (n = 0; n < 8; n++) {
buf[n] = (uch)get_byte(); /* may cause an error if EOF */
}
orig_crc = LG(buf);
orig_len = LG(buf+4);
} else if (ext_header) { /* If extended header, check it */
/* signature - 4bytes: 0x50 0x4b 0x07 0x08
* CRC-32 value
* compressed size 4-bytes
* uncompressed size 4-bytes
*/
for (n = 0; n < EXTHDR; n++) {
buf[n] = (uch)get_byte(); /* may cause an error if EOF */
}
orig_crc = LG(buf+4);
orig_len = LG(buf+12);
}
/* Validate decompression */
if (orig_crc != updcrc(outbuf, 0)) {
error("invalid compressed data--crc error");
}
if (orig_len != (ulg)bytes_out) {
error("invalid compressed data--length error");
}
/* Check if there are more entries in a pkzip file */
if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
if (to_stdout) {
WARN((stderr,
"%s: %s has more than one entry--rest ignored\n",
progname, ifname));
} else {
/* Don't destroy the input zip file */
fprintf(stderr,
"%s: %s has more than one entry -- unchanged\n",
progname, ifname);
exit_code = ERROR;
ext_header = pkzip = 0;
return ERROR;
}
}
ext_header = pkzip = 0; /* for next file */
return OK;
}
|
