crypto/rand/rand_egd.c

   1 /* Written by Ulf Moeller and Lutz Jaenicke for the OpenSSL project. */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55
  56 #include <openssl/crypto.h>
  57 #include <openssl/e_os2.h>
  58 #include <openssl/rand.h>
  59
  60 /*-
  61  * Query the EGD <URL: http://www.lothar.com/tech/crypto/>.
  62  *
  63  * This module supplies three routines:
  64  *
  65  * RAND_query_egd_bytes(path, buf, bytes)
  66  *   will actually query "bytes" bytes of entropy form the egd-socket located
  67  *   at path and will write them to buf (if supplied) or will directly feed
  68  *   it to RAND_seed() if buf==NULL.
  69  *   The number of bytes is not limited by the maximum chunk size of EGD,
  70  *   which is 255 bytes. If more than 255 bytes are wanted, several chunks
  71  *   of entropy bytes are requested. The connection is left open until the
  72  *   query is competed.
  73  *   RAND_query_egd_bytes() returns with
  74  *     -1  if an error occurred during connection or communication.
  75  *     num the number of bytes read from the EGD socket. This number is either
  76  *         the number of bytes requested or smaller, if the EGD pool is
  77  *         drained and the daemon signals that the pool is empty.
  78  *   This routine does not touch any RAND_status(). This is necessary, since
  79  *   PRNG functions may call it during initialization.
  80  *
  81  * RAND_egd_bytes(path, bytes) will query "bytes" bytes and have them
  82  *   used to seed the PRNG.
  83  *   RAND_egd_bytes() is a wrapper for RAND_query_egd_bytes() with buf=NULL.
  84  *   Unlike RAND_query_egd_bytes(), RAND_status() is used to test the
  85  *   seed status so that the return value can reflect the seed state:
  86  *     -1  if an error occurred during connection or communication _or_
  87  *         if the PRNG has still not received the required seeding.
  88  *     num the number of bytes read from the EGD socket. This number is either
  89  *         the number of bytes requested or smaller, if the EGD pool is
  90  *         drained and the daemon signals that the pool is empty.
  91  *
  92  * RAND_egd(path) will query 255 bytes and use the bytes retreived to seed
  93  *   the PRNG.
  94  *   RAND_egd() is a wrapper for RAND_egd_bytes() with numbytes=255.
  95  */
  96
  97 #ifndef OPENSSL_NO_EGD
  98
  99 # if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS) || defined(OPENSSL_SYS_MSDOS) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYS_NETWARE) || defined(OPENSSL_SYS_VOS) || defined(OPENSSL_SYS_UEFI)
 100 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
 101 {
 102     return (-1);
 103 }
 104
 105 int RAND_egd(const char *path)
 106 {
 107     return (-1);
 108 }
 109
 110 int RAND_egd_bytes(const char *path, int bytes)
 111 {
 112     return (-1);
 113 }
 114 # else
 115 #  include <openssl/opensslconf.h>
 116 #  include OPENSSL_UNISTD
 117 #  include <stddef.h>
 118 #  include <sys/types.h>
 119 #  include <sys/socket.h>
 120 #  ifndef NO_SYS_UN_H
 121 #   ifdef OPENSSL_SYS_VXWORKS
 122 #    include <streams/un.h>
 123 #   else
 124 #    include <sys/un.h>
 125 #   endif
 126 #  else
 127 struct sockaddr_un {
 128     short sun_family;           /* AF_UNIX */
 129     char sun_path[108];         /* path name (gag) */
 130 };
 131 #  endif                         /* NO_SYS_UN_H */
 132 #  include <string.h>
 133 #  include <errno.h>
 134
 135 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
 136 {
 137     int ret = 0;
 138     struct sockaddr_un addr;
 139     int len, num, numbytes;
 140     int fd = -1;
 141     int success;
 142     unsigned char egdbuf[2], tempbuf[255], *retrievebuf;
 143
 144     memset(&addr, 0, sizeof(addr));
 145     addr.sun_family = AF_UNIX;
 146     if (strlen(path) >= sizeof(addr.sun_path))
 147         return (-1);
 148     OPENSSL_strlcpy(addr.sun_path, path, sizeof addr.sun_path);
 149     len = offsetof(struct sockaddr_un, sun_path) + strlen(path);
 150     fd = socket(AF_UNIX, SOCK_STREAM, 0);
 151     if (fd == -1)
 152         return (-1);
 153     success = 0;
 154     while (!success) {
 155         if (connect(fd, (struct sockaddr *)&addr, len) == 0)
 156             success = 1;
 157         else {
 158             switch (errno) {
 159 #  ifdef EINTR
 160             case EINTR:
 161 #  endif
 162 #  ifdef EAGAIN
 163             case EAGAIN:
 164 #  endif
 165 #  ifdef EINPROGRESS
 166             case EINPROGRESS:
 167 #  endif
 168 #  ifdef EALREADY
 169             case EALREADY:
 170 #  endif
 171                 /* No error, try again */
 172                 break;
 173 #  ifdef EISCONN
 174             case EISCONN:
 175                 success = 1;
 176                 break;
 177 #  endif
 178             default:
 179                 goto err;       /* failure */
 180             }
 181         }
 182     }
 183
 184     while (bytes > 0) {
 185         egdbuf[0] = 1;
 186         egdbuf[1] = bytes < 255 ? bytes : 255;
 187         numbytes = 0;
 188         while (numbytes != 2) {
 189             num = write(fd, egdbuf + numbytes, 2 - numbytes);
 190             if (num >= 0)
 191                 numbytes += num;
 192             else {
 193                 switch (errno) {
 194 #  ifdef EINTR
 195                 case EINTR:
 196 #  endif
 197 #  ifdef EAGAIN
 198                 case EAGAIN:
 199 #  endif
 200                     /* No error, try again */
 201                     break;
 202                 default:
 203                     ret = -1;
 204                     goto err;   /* failure */
 205                 }
 206             }
 207         }
 208         numbytes = 0;
 209         while (numbytes != 1) {
 210             num = read(fd, egdbuf, 1);
 211             if (num == 0)
 212                 goto err;       /* descriptor closed */
 213             else if (num > 0)
 214                 numbytes += num;
 215             else {
 216                 switch (errno) {
 217 #  ifdef EINTR
 218                 case EINTR:
 219 #  endif
 220 #  ifdef EAGAIN
 221                 case EAGAIN:
 222 #  endif
 223                     /* No error, try again */
 224                     break;
 225                 default:
 226                     ret = -1;
 227                     goto err;   /* failure */
 228                 }
 229             }
 230         }
 231         if (egdbuf[0] == 0)
 232             goto err;
 233         if (buf)
 234             retrievebuf = buf + ret;
 235         else
 236             retrievebuf = tempbuf;
 237         numbytes = 0;
 238         while (numbytes != egdbuf[0]) {
 239             num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes);
 240             if (num == 0)
 241                 goto err;       /* descriptor closed */
 242             else if (num > 0)
 243                 numbytes += num;
 244             else {
 245                 switch (errno) {
 246 #  ifdef EINTR
 247                 case EINTR:
 248 #  endif
 249 #  ifdef EAGAIN
 250                 case EAGAIN:
 251 #  endif
 252                     /* No error, try again */
 253                     break;
 254                 default:
 255                     ret = -1;
 256                     goto err;   /* failure */
 257                 }
 258             }
 259         }
 260         ret += egdbuf[0];
 261         bytes -= egdbuf[0];
 262         if (!buf)
 263             RAND_seed(tempbuf, egdbuf[0]);
 264     }
 265  err:
 266     if (fd != -1)
 267         close(fd);
 268     return (ret);
 269 }
 270
 271 int RAND_egd_bytes(const char *path, int bytes)
 272 {
 273     int num, ret = 0;
 274
 275     num = RAND_query_egd_bytes(path, NULL, bytes);
 276     if (num < 1)
 277         goto err;
 278     if (RAND_status() == 1)
 279         ret = num;
 280  err:
 281     return (ret);
 282 }
 283
 284 int RAND_egd(const char *path)
 285 {
 286     return (RAND_egd_bytes(path, 255));
 287 }
 288
 289 # endif
 290
 291 #else /* OPENSSL_NO_EGD */
 292 # if PEDANTIC
 293 static void *dummy = &dummy;
 294 # endif
 295 #endif