| Glenn L McGrath | 7ca04f3 | 2002-09-25 02:47:48 +0000 | [diff] [blame^] | 1 | /* vi: set sw=4 ts=4: */ |
| 2 | /* |
| 3 | * busybox gunzip trailing header handler |
| 4 | * Copyright Glenn McGrath 2002 |
| 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 of the License, or |
| 9 | * (at your option) 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 |
| 18 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 19 | */ |
| 20 | |
| 21 | |
| 22 | #include <sys/types.h> |
| 23 | #include <sys/wait.h> |
| 24 | #include <signal.h> |
| 25 | #include <stdlib.h> |
| 26 | #include <string.h> |
| 27 | #include <unistd.h> |
| 28 | #include <fcntl.h> |
| 29 | #include "config.h" |
| 30 | #include "busybox.h" |
| 31 | #include "unarchive.h" |
| 32 | |
| 33 | extern unsigned int gunzip_crc; |
| 34 | extern unsigned int gunzip_bytes_out; |
| 35 | extern unsigned char *gunzip_in_buffer; |
| 36 | extern unsigned char gunzip_in_buffer_count; |
| 37 | |
| 38 | extern void check_trailer_gzip(int src_fd) |
| 39 | { |
| 40 | |
| 41 | unsigned int stored_crc = 0; |
| 42 | unsigned char count; |
| 43 | |
| 44 | /* top up the input buffer with the rest of the trailer */ |
| 45 | xread_all(src_fd, &gunzip_in_buffer[gunzip_in_buffer_count], 8 - gunzip_in_buffer_count); |
| 46 | for (count = 0; count != 4; count++) { |
| 47 | stored_crc |= (gunzip_in_buffer[count] << (count * 8)); |
| 48 | } |
| 49 | |
| 50 | /* Validate decompression - crc */ |
| 51 | if (stored_crc != (gunzip_crc ^ 0xffffffffL)) { |
| 52 | error_msg("invalid compressed data--crc error"); |
| 53 | } |
| 54 | |
| 55 | /* Validate decompression - size */ |
| 56 | if (gunzip_bytes_out != |
| 57 | (gunzip_in_buffer[4] | (gunzip_in_buffer[5] << 8) | |
| 58 | (gunzip_in_buffer[6] << 16) | (gunzip_in_buffer[7] << 24))) { |
| 59 | error_msg("invalid compressed data--length error"); |
| 60 | } |
| 61 | |
| 62 | } |