| 1 | /* |
| 2 | * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 as published |
| 6 | * by the Free Software Foundation. |
| 7 | * |
| 8 | */ |
| 9 | |
| 10 | #include <stdio.h> |
| 11 | #include <stdlib.h> |
| 12 | #include <stdint.h> |
| 13 | #include <string.h> |
| 14 | #include <libgen.h> |
| 15 | #include <getopt.h> /* for getopt() */ |
| 16 | #include <stdarg.h> |
| 17 | |
| 18 | #include "buffalo-lib.h" |
| 19 | |
| 20 | #define ERR(fmt, args...) do { \ |
| 21 | fflush(0); \ |
| 22 | fprintf(stderr, "[%s] *** error: " fmt "\n", \ |
| 23 | progname, ## args ); \ |
| 24 | } while (0) |
| 25 | |
| 26 | static char *progname; |
| 27 | static char *ifname; |
| 28 | static char *ofname; |
| 29 | static int do_decrypt; |
| 30 | |
| 31 | void usage(int status) |
| 32 | { |
| 33 | FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout; |
| 34 | |
| 35 | fprintf(stream, "Usage: %s [OPTIONS...]\n", progname); |
| 36 | fprintf(stream, |
| 37 | "\n" |
| 38 | "Options:\n" |
| 39 | " -d decrypt instead of encrypt\n" |
| 40 | " -i <file> read input from the file <file>\n" |
| 41 | " -o <file> write output to the file <file>\n" |
| 42 | " -h show this screen\n" |
| 43 | ); |
| 44 | |
| 45 | exit(status); |
| 46 | } |
| 47 | |
| 48 | static const unsigned char *crypt_key1 = (unsigned char *) |
| 49 | "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; |
| 50 | static const unsigned char *crypt_key2 = (unsigned char *) |
| 51 | "XYZ0123hijklmnopqABCDEFGHrstuvabcdefgwxyzIJKLMSTUVW456789NOPQR"; |
| 52 | |
| 53 | static void crypt_header(unsigned char *buf, ssize_t len, |
| 54 | const unsigned char *key1, const unsigned char *key2) |
| 55 | { |
| 56 | ssize_t i; |
| 57 | |
| 58 | for (i = 0; i < len; i++) { |
| 59 | unsigned int j; |
| 60 | |
| 61 | for (j = 0; key1[j]; j++) |
| 62 | if (buf[i] == key1[j]) { |
| 63 | buf[i] = key2[j]; |
| 64 | break; |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | static int crypt_file(void) |
| 70 | { |
| 71 | unsigned char *buf = NULL; |
| 72 | ssize_t src_len; |
| 73 | ssize_t crypt_len; |
| 74 | int err; |
| 75 | int ret = -1; |
| 76 | |
| 77 | src_len = get_file_size(ifname); |
| 78 | if (src_len < 0) { |
| 79 | ERR("unable to get size of '%s'", ifname); |
| 80 | goto out; |
| 81 | } |
| 82 | |
| 83 | buf = malloc(src_len); |
| 84 | if (buf == NULL) { |
| 85 | ERR("no memory for the buffer"); |
| 86 | goto out; |
| 87 | } |
| 88 | |
| 89 | err = read_file_to_buf(ifname, buf, src_len); |
| 90 | if (err) { |
| 91 | ERR("unable to read from file '%s'", ifname); |
| 92 | goto out; |
| 93 | } |
| 94 | |
| 95 | crypt_len = (src_len > 512) ? 512 : src_len; |
| 96 | if (do_decrypt) |
| 97 | crypt_header(buf, 512, crypt_key2, crypt_key1); |
| 98 | else |
| 99 | crypt_header(buf, 512, crypt_key1, crypt_key2); |
| 100 | |
| 101 | err = write_buf_to_file(ofname, buf, src_len); |
| 102 | if (err) { |
| 103 | ERR("unable to write to file '%s'", ofname); |
| 104 | goto out; |
| 105 | } |
| 106 | |
| 107 | ret = 0; |
| 108 | |
| 109 | out: |
| 110 | free(buf); |
| 111 | return ret; |
| 112 | } |
| 113 | |
| 114 | static int check_params(void) |
| 115 | { |
| 116 | int ret = -1; |
| 117 | |
| 118 | if (ifname == NULL) { |
| 119 | ERR("no input file specified"); |
| 120 | goto out; |
| 121 | } |
| 122 | |
| 123 | if (ofname == NULL) { |
| 124 | ERR("no output file specified"); |
| 125 | goto out; |
| 126 | } |
| 127 | |
| 128 | ret = 0; |
| 129 | |
| 130 | out: |
| 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | int main(int argc, char *argv[]) |
| 135 | { |
| 136 | int res = EXIT_FAILURE; |
| 137 | int err; |
| 138 | |
| 139 | progname = basename(argv[0]); |
| 140 | |
| 141 | while ( 1 ) { |
| 142 | int c; |
| 143 | |
| 144 | c = getopt(argc, argv, "di:o:h"); |
| 145 | if (c == -1) |
| 146 | break; |
| 147 | |
| 148 | switch (c) { |
| 149 | case 'd': |
| 150 | do_decrypt = 1; |
| 151 | break; |
| 152 | case 'i': |
| 153 | ifname = optarg; |
| 154 | break; |
| 155 | case 'o': |
| 156 | ofname = optarg; |
| 157 | break; |
| 158 | case 'h': |
| 159 | usage(EXIT_SUCCESS); |
| 160 | break; |
| 161 | default: |
| 162 | usage(EXIT_FAILURE); |
| 163 | break; |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | err = check_params(); |
| 168 | if (err) |
| 169 | goto out; |
| 170 | |
| 171 | err = crypt_file(); |
| 172 | if (err) |
| 173 | goto out; |
| 174 | |
| 175 | res = EXIT_SUCCESS; |
| 176 | |
| 177 | out: |
| 178 | return res; |
| 179 | } |
| 180 | |
