tools/firmware-utils/src/buffalo-tftp.c

   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 }