crypto/libressl/crypto/rand/randfile.c

   1 /* $OpenBSD: randfile.c,v 1.41 2015/07/18 22:46:42 beck Exp $ */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 #include <errno.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <unistd.h>
  63 #include <string.h>
  64
  65 #include <openssl/crypto.h>
  66 #include <openssl/rand.h>
  67 #include <openssl/buffer.h>
  68
  69 #include <sys/types.h>
  70 #include <sys/stat.h>
  71 #include <fcntl.h>
  72
  73 #undef BUFSIZE
  74 #define BUFSIZE 1024
  75 #define RAND_DATA 1024
  76
  77 /* Note that these functions should not be used. */
  78
  79 int
  80 RAND_load_file(const char *file, long bytes)
  81 {
  82         /* the "whole" file */
  83         if (bytes == -1)
  84                 return 123456;
  85         else
  86                 return bytes;
  87 }
  88
  89 int
  90 RAND_write_file(const char *file)
  91 {
  92         unsigned char buf[BUFSIZE];
  93         int i, ret = 0;
  94         FILE *out = NULL;
  95         int n, fd;
  96         struct stat sb;
  97
  98         /*
  99          * If this file is a device, avoid opening it.
 100          * XXX TOCTOU
 101          */
 102         if (stat(file, &sb) != -1 &&
 103             (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode))) {
 104                 return (1);
 105         }
 106
 107         fd = open(file, O_WRONLY|O_CREAT, 0600);
 108         if (fd == -1)
 109                 return (1);
 110         out = fdopen(fd, "wb");
 111
 112         if (out == NULL) {
 113                 close(fd);
 114                 return (1);
 115         }
 116
 117         n = RAND_DATA;
 118         for (;;) {
 119                 i = (n > BUFSIZE) ? BUFSIZE : n;
 120                 n -= BUFSIZE;
 121                 arc4random_buf(buf, i);
 122                 i = fwrite(buf, 1, i, out);
 123                 if (i <= 0) {
 124                         ret = 0;
 125                         break;
 126                 }
 127                 ret += i;
 128                 if (n <= 0)
 129                         break;
 130         }
 131
 132         fclose(out);
 133         explicit_bzero(buf, BUFSIZE);
 134         return ret;
 135 }
 136
 137 const char *
 138 RAND_file_name(char * buf, size_t size)
 139 {
 140         if (strlcpy(buf, "/dev/urandom", size) >= size)
 141                 return (NULL);
 142         return buf;
 143 }