crypto/rand/rand_unix.c

   1 /* crypto/rand/rand_unix.c */
   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  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
  60  *
  61  * Redistribution and use in source and binary forms, with or without
  62  * modification, are permitted provided that the following conditions
  63  * are met:
  64  *
  65  * 1. Redistributions of source code must retain the above copyright
  66  *    notice, this list of conditions and the following disclaimer.
  67  *
  68  * 2. Redistributions in binary form must reproduce the above copyright
  69  *    notice, this list of conditions and the following disclaimer in
  70  *    the documentation and/or other materials provided with the
  71  *    distribution.
  72  *
  73  * 3. All advertising materials mentioning features or use of this
  74  *    software must display the following acknowledgment:
  75  *    "This product includes software developed by the OpenSSL Project
  76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  77  *
  78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  79  *    endorse or promote products derived from this software without
  80  *    prior written permission. For written permission, please contact
  81  *    openssl-core@openssl.org.
  82  *
  83  * 5. Products derived from this software may not be called "OpenSSL"
  84  *    nor may "OpenSSL" appear in their names without prior written
  85  *    permission of the OpenSSL Project.
  86  *
  87  * 6. Redistributions of any form whatsoever must retain the following
  88  *    acknowledgment:
  89  *    "This product includes software developed by the OpenSSL Project
  90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  91  *
  92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 103  * OF THE POSSIBILITY OF SUCH DAMAGE.
 104  * ====================================================================
 105  *
 106  * This product includes cryptographic software written by Eric Young
 107  * (eay@cryptsoft.com).  This product includes software written by Tim
 108  * Hudson (tjh@cryptsoft.com).
 109  *
 110  */
 111
 112 #include "cryptlib.h"
 113 #include <openssl/rand.h>
 114 #include "rand_lcl.h"
 115
 116 #if !(defined(WINDOWS) || defined(WIN32) || defined(VMS))
 117
 118 #include <sys/types.h>
 119 #include <sys/time.h>
 120 #include <sys/times.h>
 121 #include <fcntl.h>
 122 #include <unistd.h>
 123 #include <time.h>
 124
 125 int RAND_poll(void)
 126 {
 127         unsigned long l;
 128         pid_t curr_pid = getpid();
 129 #if defined(DEVRANDOM) || defined(DEVRANDOM_EGD)
 130         unsigned char tmpbuf[ENTROPY_NEEDED];
 131         int n = 0;
 132 #endif
 133 #ifdef DEVRANDOM
 134         static const char *randomfiles[] = { DEVRANDOM, NULL };
 135         const char **randomfile = NULL;
 136         int fd;
 137 #endif
 138 #ifdef DEVRANDOM_EGD
 139         static const char *egdsockets[] = { DEVRANDOM_EGD, NULL };
 140         const char **egdsocket = NULL;
 141 #endif
 142
 143 #ifdef DEVRANDOM
 144         /* Use a random entropy pool device. Linux, FreeBSD and OpenBSD
 145          * have this. Use /dev/urandom if you can as /dev/random may block
 146          * if it runs out of random entries.  */
 147
 148         for (randomfile = randomfiles; *randomfile && n < ENTROPY_NEEDED; randomfile++)
 149                 {
 150                 if ((fd = open(*randomfile, O_RDONLY|O_NONBLOCK
 151 #ifdef O_NOCTTY /* If it happens to be a TTY (god forbid), do not make it
 152                    our controlling tty */
 153                         |O_NOCTTY
 154 #endif
 155 #ifdef O_NOFOLLOW /* Fail if the file is a symbolic link */
 156                         |O_NOFOLLOW
 157 #endif
 158                         )) >= 0)
 159                         {
 160                         struct timeval t = { 0, 10*1000 }; /* Spend 10ms on
 161                                                               each file. */
 162                         int r;
 163                         fd_set fset;
 164
 165                         do
 166                                 {
 167                                 FD_ZERO(&fset);
 168                                 FD_SET(fd, &fset);
 169                                 r = -1;
 170
 171                                 if (select(fd+1,&fset,NULL,NULL,&t) < 0)
 172                                         t.tv_usec=0;
 173                                 else if (FD_ISSET(fd, &fset))
 174                                         {
 175                                         r=read(fd,(unsigned char *)tmpbuf+n,
 176                                                ENTROPY_NEEDED-n);
 177                                         if (r > 0)
 178                                                 n += r;
 179                                         }
 180
 181                                 /* Some Unixen will update t, some
 182                                    won't.  For those who won't, give
 183                                    up here, otherwise, we will do
 184                                    this once again for the remaining
 185                                    time. */
 186                                 if (t.tv_usec == 10*1000)
 187                                         t.tv_usec=0;
 188                                 }
 189                         while ((r > 0 || (errno == EINTR || errno == EAGAIN))
 190                                 && t.tv_usec != 0 && n < ENTROPY_NEEDED);
 191
 192                         close(fd);
 193                         }
 194                 }
 195 #endif
 196
 197 #ifdef DEVRANDOM_EGD
 198         /* Use an EGD socket to read entropy from an EGD or PRNGD entropy
 199          * collecting daemon. */
 200
 201         for (egdsocket = egdsockets; *egdsocket && n < ENTROPY_NEEDED; egdsocket++)
 202                 {
 203                 int r;
 204
 205                 r = RAND_query_egd_bytes(*egdsocket, (unsigned char *)tmpbuf+n,
 206                                          ENTROPY_NEEDED-n);
 207                 if (r > 0)
 208                         n += r;
 209                 }
 210 #endif
 211
 212 #if defined(DEVRANDOM) || defined(DEVRANDOM_EGD)
 213         if (n > 0)
 214                 {
 215                 RAND_add(tmpbuf,sizeof tmpbuf,n);
 216                 memset(tmpbuf,0,n);
 217                 }
 218 #endif
 219
 220         /* put in some default random data, we need more than just this */
 221         l=curr_pid;
 222         RAND_add(&l,sizeof(l),0);
 223         l=getuid();
 224         RAND_add(&l,sizeof(l),0);
 225
 226         l=time(NULL);
 227         RAND_add(&l,sizeof(l),0);
 228
 229 #if defined(DEVRANDOM) || defined(DEVRANDOM_EGD)
 230         return 1;
 231 #endif
 232         return 0;
 233 }
 234
 235 #endif