release/src/router/nettle/examples/io.c

   1 /* io.c
   2  *
   3  * Miscellaneous functions used by the example programs.
   4  */
   5
   6 /* nettle, low-level cryptographics library
   7  *
   8  * Copyright (C) 2002 Niels Möller
   9  *
  10  * The nettle library is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 of the License, or (at your
  13  * option) any later version.
  14  *
  15  * The nettle library is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  18  * License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with the nettle library; see the file COPYING.LIB.  If not, write to
  22  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
  23  * MA 02111-1301, USA.
  24  */
  25
  26 #if HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <stdarg.h>
  31 #include <stdlib.h>
  32
  33 /* For errno and strerror */
  34 #include <errno.h>
  35 #include <string.h>
  36
  37 #include "io.h"
  38
  39 #define RANDOM_DEVICE "/dev/urandom"
  40 #define BUFSIZE 1000
  41
  42 int quiet_flag = 0;
  43
  44 void *
  45 xalloc(size_t size)
  46 {
  47   void *p = malloc(size);
  48   if (!p)
  49     {
  50       fprintf(stderr, "Virtual memory exhausted.\n");
  51       abort();
  52     }
  53
  54   return p;
  55 }
  56
  57 void
  58 werror(const char *format, ...)
  59 {
  60   if (!quiet_flag)
  61     {
  62       va_list args;
  63       va_start(args, format);
  64       vfprintf(stderr, format, args);
  65       va_end(args);
  66     }
  67 }
  68
  69 #define MIN(a,b) (((a) < (b)) ? (a) : (b))
  70
  71 unsigned
  72 read_file(const char *name, unsigned max_size, char **contents)
  73 {
  74   unsigned size, done;
  75   char *buffer;
  76   FILE *f;
  77
  78   f = fopen(name, "rb");
  79   if (!f)
  80     {
  81       werror("Opening `%s' failed: %s\n", name, strerror(errno));
  82       return 0;
  83     }
  84
  85   size = 100;
  86
  87   for (buffer = NULL, done = 0;; size *= 2)
  88     {
  89       char *p;
  90
  91       if (max_size && size > max_size)
  92         size = max_size;
  93
  94       /* Space for terminating NUL */
  95       p = realloc(buffer, size + 1);
  96
  97       if (!p)
  98         {
  99         fail:
 100           fclose(f);
 101           free(buffer);
 102           *contents = NULL;
 103           return 0;
 104         }
 105
 106       buffer = p;
 107       done += fread(buffer + done, 1, size - done, f);
 108
 109       if (done < size)
 110         {
 111           /* Short count means EOF or read error */
 112           if (ferror(f))
 113             {
 114               fprintf (stderr, "Reading `%s' failed: %s\n",
 115                        name, strerror(errno));
 116
 117               goto fail;
 118             }
 119           if (done == 0)
 120             /* Treat empty file as error */
 121             goto fail;
 122
 123           break;
 124         }
 125
 126       if (size == max_size)
 127         break;
 128     }
 129
 130   fclose(f);
 131
 132   /* NUL-terminate the data. */
 133   buffer[done] = '\0';
 134   *contents = buffer;
 135
 136   return done;
 137 }
 138
 139 int
 140 write_string(FILE *f, unsigned size, const char *buffer)
 141 {
 142   size_t res = fwrite(buffer, 1, size, f);
 143
 144   return res == size;
 145 }
 146
 147 int
 148 write_file(const char *name, unsigned size, const char *buffer)
 149 {
 150   FILE *f = fopen(name, "wb");
 151   int res;
 152
 153   if (!f)
 154     return 0;
 155
 156   res = write_string(f, size, buffer);
 157   return fclose(f) == 0 && res;
 158 }
 159
 160 int
 161 simple_random(struct yarrow256_ctx *ctx, const char *name)
 162 {
 163   unsigned length;
 164   char *buffer;
 165
 166   if (name)
 167     length = read_file(name, 0, &buffer);
 168   else
 169     length = read_file(RANDOM_DEVICE, 20, &buffer);
 170
 171   if (!length)
 172     return 0;
 173
 174   yarrow256_seed(ctx, length, buffer);
 175
 176   free(buffer);
 177
 178   return 1;
 179 }
 180
 181 int
 182 hash_file(const struct nettle_hash *hash, void *ctx, FILE *f)
 183 {
 184   for (;;)
 185     {
 186       char buffer[BUFSIZE];
 187       size_t res = fread(buffer, 1, sizeof(buffer), f);
 188       if (ferror(f))
 189         return 0;
 190
 191       hash->update(ctx, res, buffer);
 192       if (feof(f))
 193         return 1;
 194     }
 195 }