| 1 | /* unzip.c -- decompress files in gzip or pkzip format.
|
|---|
| 2 |
|
|---|
| 3 | Copyright (C) 1997, 1998, 1999 Free Software Foundation, Inc.
|
|---|
| 4 | Copyright (C) 1992-1993 Jean-loup Gailly
|
|---|
| 5 |
|
|---|
| 6 | This program is free software; you can redistribute it and/or modify
|
|---|
| 7 | it under the terms of the GNU General Public License as published by
|
|---|
| 8 | the Free Software Foundation; either version 2, or (at your option)
|
|---|
| 9 | any later version.
|
|---|
| 10 |
|
|---|
| 11 | This program is distributed in the hope that it will be useful,
|
|---|
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|---|
| 14 | GNU General Public License for more details.
|
|---|
| 15 |
|
|---|
| 16 | You should have received a copy of the GNU General Public License
|
|---|
| 17 | along with this program; if not, write to the Free Software Foundation,
|
|---|
| 18 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
|
|---|
| 19 |
|
|---|
| 20 | /*
|
|---|
| 21 | * The code in this file is derived from the file funzip.c written
|
|---|
| 22 | * and put in the public domain by Mark Adler.
|
|---|
| 23 | */
|
|---|
| 24 |
|
|---|
| 25 | /*
|
|---|
| 26 | This version can extract files in gzip or pkzip format.
|
|---|
| 27 | For the latter, only the first entry is extracted, and it has to be
|
|---|
| 28 | either deflated or stored.
|
|---|
| 29 | */
|
|---|
| 30 |
|
|---|
| 31 | #ifdef RCSID
|
|---|
| 32 | static char rcsid[] = "$Id: unzip.c,v 1.4 2006/11/20 08:40:34 eggert Exp $";
|
|---|
| 33 | #endif
|
|---|
| 34 |
|
|---|
| 35 | #include <config.h>
|
|---|
| 36 | #include "tailor.h"
|
|---|
| 37 | #include "gzip.h"
|
|---|
| 38 | #include "crypt.h"
|
|---|
| 39 |
|
|---|
| 40 | /* PKZIP header definitions */
|
|---|
| 41 | #define LOCSIG 0x04034b50L /* four-byte lead-in (lsb first) */
|
|---|
| 42 | #define LOCFLG 6 /* offset of bit flag */
|
|---|
| 43 | #define CRPFLG 1 /* bit for encrypted entry */
|
|---|
| 44 | #define EXTFLG 8 /* bit for extended local header */
|
|---|
| 45 | #define LOCHOW 8 /* offset of compression method */
|
|---|
| 46 | #define LOCTIM 10 /* file mod time (for decryption) */
|
|---|
| 47 | #define LOCCRC 14 /* offset of crc */
|
|---|
| 48 | #define LOCSIZ 18 /* offset of compressed size */
|
|---|
| 49 | #define LOCLEN 22 /* offset of uncompressed length */
|
|---|
| 50 | #define LOCFIL 26 /* offset of file name field length */
|
|---|
| 51 | #define LOCEXT 28 /* offset of extra field length */
|
|---|
| 52 | #define LOCHDR 30 /* size of local header, including sig */
|
|---|
| 53 | #define EXTHDR 16 /* size of extended local header, inc sig */
|
|---|
| 54 | #define RAND_HEAD_LEN 12 /* length of encryption random header */
|
|---|
| 55 |
|
|---|
| 56 |
|
|---|
| 57 | /* Globals */
|
|---|
| 58 |
|
|---|
| 59 | int decrypt; /* flag to turn on decryption */
|
|---|
| 60 | char *key; /* not used--needed to link crypt.c */
|
|---|
| 61 | int pkzip = 0; /* set for a pkzip file */
|
|---|
| 62 | int ext_header = 0; /* set if extended local header */
|
|---|
| 63 |
|
|---|
| 64 | /* ===========================================================================
|
|---|
| 65 | * Check zip file and advance inptr to the start of the compressed data.
|
|---|
| 66 | * Get ofname from the local header if necessary.
|
|---|
| 67 | */
|
|---|
| 68 | int check_zipfile(in)
|
|---|
| 69 | int in; /* input file descriptors */
|
|---|
| 70 | {
|
|---|
| 71 | uch *h = inbuf + inptr; /* first local header */
|
|---|
| 72 |
|
|---|
| 73 | ifd = in;
|
|---|
| 74 |
|
|---|
| 75 | /* Check validity of local header, and skip name and extra fields */
|
|---|
| 76 | inptr += LOCHDR + SH(h + LOCFIL) + SH(h + LOCEXT);
|
|---|
| 77 |
|
|---|
| 78 | if (inptr > insize || LG(h) != LOCSIG) {
|
|---|
| 79 | fprintf(stderr, "\n%s: %s: not a valid zip file\n",
|
|---|
| 80 | program_name, ifname);
|
|---|
| 81 | exit_code = ERROR;
|
|---|
| 82 | return ERROR;
|
|---|
| 83 | }
|
|---|
| 84 | method = h[LOCHOW];
|
|---|
| 85 | if (method != STORED && method != DEFLATED) {
|
|---|
| 86 | fprintf(stderr,
|
|---|
| 87 | "\n%s: %s: first entry not deflated or stored -- use unzip\n",
|
|---|
| 88 | program_name, ifname);
|
|---|
| 89 | exit_code = ERROR;
|
|---|
| 90 | return ERROR;
|
|---|
| 91 | }
|
|---|
| 92 |
|
|---|
| 93 | /* If entry encrypted, decrypt and validate encryption header */
|
|---|
| 94 | if ((decrypt = h[LOCFLG] & CRPFLG) != 0) {
|
|---|
| 95 | fprintf(stderr, "\n%s: %s: encrypted file -- use unzip\n",
|
|---|
| 96 | program_name, ifname);
|
|---|
| 97 | exit_code = ERROR;
|
|---|
| 98 | return ERROR;
|
|---|
| 99 | }
|
|---|
| 100 |
|
|---|
| 101 | /* Save flags for unzip() */
|
|---|
| 102 | ext_header = (h[LOCFLG] & EXTFLG) != 0;
|
|---|
| 103 | pkzip = 1;
|
|---|
| 104 |
|
|---|
| 105 | /* Get ofname and time stamp from local header (to be done) */
|
|---|
| 106 | return OK;
|
|---|
| 107 | }
|
|---|
| 108 |
|
|---|
| 109 | /* ===========================================================================
|
|---|
| 110 | * Unzip in to out. This routine works on both gzip and pkzip files.
|
|---|
| 111 | *
|
|---|
| 112 | * IN assertions: the buffer inbuf contains already the beginning of
|
|---|
| 113 | * the compressed data, from offsets inptr to insize-1 included.
|
|---|
| 114 | * The magic header has already been checked. The output buffer is cleared.
|
|---|
| 115 | */
|
|---|
| 116 | int unzip(in, out)
|
|---|
| 117 | int in, out; /* input and output file descriptors */
|
|---|
| 118 | {
|
|---|
| 119 | ulg orig_crc = 0; /* original crc */
|
|---|
| 120 | ulg orig_len = 0; /* original uncompressed length */
|
|---|
| 121 | int n;
|
|---|
| 122 | uch buf[EXTHDR]; /* extended local header */
|
|---|
| 123 | int err = OK;
|
|---|
| 124 |
|
|---|
| 125 | ifd = in;
|
|---|
| 126 | ofd = out;
|
|---|
| 127 |
|
|---|
| 128 | updcrc(NULL, 0); /* initialize crc */
|
|---|
| 129 |
|
|---|
| 130 | if (pkzip && !ext_header) { /* crc and length at the end otherwise */
|
|---|
| 131 | orig_crc = LG(inbuf + LOCCRC);
|
|---|
| 132 | orig_len = LG(inbuf + LOCLEN);
|
|---|
| 133 | }
|
|---|
| 134 |
|
|---|
| 135 | /* Decompress */
|
|---|
| 136 | if (method == DEFLATED) {
|
|---|
| 137 |
|
|---|
| 138 | int res = inflate();
|
|---|
| 139 |
|
|---|
| 140 | if (res == 3) {
|
|---|
| 141 | xalloc_die ();
|
|---|
| 142 | } else if (res != 0) {
|
|---|
| 143 | gzip_error ("invalid compressed data--format violated");
|
|---|
| 144 | }
|
|---|
| 145 |
|
|---|
| 146 | } else if (pkzip && method == STORED) {
|
|---|
| 147 |
|
|---|
| 148 | register ulg n = LG(inbuf + LOCLEN);
|
|---|
| 149 |
|
|---|
| 150 | if (n != LG(inbuf + LOCSIZ) - (decrypt ? RAND_HEAD_LEN : 0)) {
|
|---|
| 151 |
|
|---|
| 152 | fprintf(stderr, "len %ld, siz %ld\n", n, LG(inbuf + LOCSIZ));
|
|---|
| 153 | gzip_error ("invalid compressed data--length mismatch");
|
|---|
| 154 | }
|
|---|
| 155 | while (n--) {
|
|---|
| 156 | uch c = (uch)get_byte();
|
|---|
| 157 | put_ubyte(c);
|
|---|
| 158 | }
|
|---|
| 159 | flush_window();
|
|---|
| 160 | } else {
|
|---|
| 161 | gzip_error ("internal error, invalid method");
|
|---|
| 162 | }
|
|---|
| 163 |
|
|---|
| 164 | /* Get the crc and original length */
|
|---|
| 165 | if (!pkzip) {
|
|---|
| 166 | /* crc32 (see algorithm.doc)
|
|---|
| 167 | * uncompressed input size modulo 2^32
|
|---|
| 168 | */
|
|---|
| 169 | for (n = 0; n < 8; n++) {
|
|---|
| 170 | buf[n] = (uch)get_byte(); /* may cause an error if EOF */
|
|---|
| 171 | }
|
|---|
| 172 | orig_crc = LG(buf);
|
|---|
| 173 | orig_len = LG(buf+4);
|
|---|
| 174 |
|
|---|
| 175 | } else if (ext_header) { /* If extended header, check it */
|
|---|
| 176 | /* signature - 4bytes: 0x50 0x4b 0x07 0x08
|
|---|
| 177 | * CRC-32 value
|
|---|
| 178 | * compressed size 4-bytes
|
|---|
| 179 | * uncompressed size 4-bytes
|
|---|
| 180 | */
|
|---|
| 181 | for (n = 0; n < EXTHDR; n++) {
|
|---|
| 182 | buf[n] = (uch)get_byte(); /* may cause an error if EOF */
|
|---|
| 183 | }
|
|---|
| 184 | orig_crc = LG(buf+4);
|
|---|
| 185 | orig_len = LG(buf+12);
|
|---|
| 186 | }
|
|---|
| 187 |
|
|---|
| 188 | /* Validate decompression */
|
|---|
| 189 | if (orig_crc != updcrc(outbuf, 0)) {
|
|---|
| 190 | fprintf(stderr, "\n%s: %s: invalid compressed data--crc error\n",
|
|---|
| 191 | program_name, ifname);
|
|---|
| 192 | err = ERROR;
|
|---|
| 193 | }
|
|---|
| 194 | if (orig_len != (ulg)(bytes_out & 0xffffffff)) {
|
|---|
| 195 | fprintf(stderr, "\n%s: %s: invalid compressed data--length error\n",
|
|---|
| 196 | program_name, ifname);
|
|---|
| 197 | err = ERROR;
|
|---|
| 198 | }
|
|---|
| 199 |
|
|---|
| 200 | /* Check if there are more entries in a pkzip file */
|
|---|
| 201 | if (pkzip && inptr + 4 < insize && LG(inbuf+inptr) == LOCSIG) {
|
|---|
| 202 | if (to_stdout) {
|
|---|
| 203 | WARN((stderr,
|
|---|
| 204 | "%s: %s has more than one entry--rest ignored\n",
|
|---|
| 205 | program_name, ifname));
|
|---|
| 206 | } else {
|
|---|
| 207 | /* Don't destroy the input zip file */
|
|---|
| 208 | fprintf(stderr,
|
|---|
| 209 | "%s: %s has more than one entry -- unchanged\n",
|
|---|
| 210 | program_name, ifname);
|
|---|
| 211 | err = ERROR;
|
|---|
| 212 | }
|
|---|
| 213 | }
|
|---|
| 214 | ext_header = pkzip = 0; /* for next file */
|
|---|
| 215 | if (err == OK) return OK;
|
|---|
| 216 | exit_code = ERROR;
|
|---|
| 217 | if (!test) abort_gzip();
|
|---|
| 218 | return err;
|
|---|
| 219 | }
|
|---|
