crypto/rand/rand_egd.c

   1 /* crypto/rand/rand_egd.c */
   2 /* Written by Ulf Moeller and Lutz Jaenicke for the OpenSSL project. */
   3 /* ====================================================================
   4  * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  *
  18  * 3. All advertising materials mentioning features or use of this
  19  *    software must display the following acknowledgment:
  20  *    "This product includes software developed by the OpenSSL Project
  21  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  22  *
  23  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  24  *    endorse or promote products derived from this software without
  25  *    prior written permission. For written permission, please contact
  26  *    openssl-core@openssl.org.
  27  *
  28  * 5. Products derived from this software may not be called "OpenSSL"
  29  *    nor may "OpenSSL" appear in their names without prior written
  30  *    permission of the OpenSSL Project.
  31  *
  32  * 6. Redistributions of any form whatsoever must retain the following
  33  *    acknowledgment:
  34  *    "This product includes software developed by the OpenSSL Project
  35  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  36  *
  37  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  38  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  39  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  40  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  41  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  42  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  43  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  44  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  45  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  46  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  47  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  48  * OF THE POSSIBILITY OF SUCH DAMAGE.
  49  * ====================================================================
  50  *
  51  * This product includes cryptographic software written by Eric Young
  52  * (eay@cryptsoft.com).  This product includes software written by Tim
  53  * Hudson (tjh@cryptsoft.com).
  54  *
  55  */
  56
  57 #include <openssl/rand.h>
  58
  59 /*
  60  * Query the EGD <URL: http://www.lothar.com/tech/crypto/>.
  61  *
  62  * This module supplies three routines:
  63  *
  64  * RAND_query_egd_bytes(path, buf, bytes)
  65  *   will actually query "bytes" bytes of entropy form the egd-socket located
  66  *   at path and will write them to buf (if supplied) or will directly feed
  67  *   it to RAND_seed() if buf==NULL.
  68  *   The number of bytes is not limited by the maximum chunk size of EGD,
  69  *   which is 255 bytes. If more than 255 bytes are wanted, several chunks
  70  *   of entropy bytes are requested. The connection is left open until the
  71  *   query is competed.
  72  *   RAND_query_egd_bytes() returns with
  73  *     -1  if an error occured during connection or communication.
  74  *     num the number of bytes read from the EGD socket. This number is either
  75  *         the number of bytes requested or smaller, if the EGD pool is
  76  *         drained and the daemon signals that the pool is empty.
  77  *   This routine does not touch any RAND_status(). This is necessary, since
  78  *   PRNG functions may call it during initialization.
  79  *
  80  * RAND_egd_bytes(path, bytes) will query "bytes" bytes and have them
  81  *   used to seed the PRNG.
  82  *   RAND_egd_bytes() is a wrapper for RAND_query_egd_bytes() with buf=NULL.
  83  *   Unlike RAND_query_egd_bytes(), RAND_status() is used to test the
  84  *   seed status so that the return value can reflect the seed state:
  85  *     -1  if an error occured during connection or communication _or_
  86  *         if the PRNG has still not received the required seeding.
  87  *     num the number of bytes read from the EGD socket. This number is either
  88  *         the number of bytes requested or smaller, if the EGD pool is
  89  *         drained and the daemon signals that the pool is empty.
  90  *
  91  * RAND_egd(path) will query 255 bytes and use the bytes retreived to seed
  92  *   the PRNG.
  93  *   RAND_egd() is a wrapper for RAND_egd_bytes() with numbytes=255.
  94  */
  95
  96 #if defined(WIN32) || defined(VMS) || defined(__VMS)
  97 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
  98         {
  99         return(-1);
 100         }
 101 int RAND_egd(const char *path)
 102         {
 103         return(-1);
 104         }
 105
 106 int RAND_egd_bytes(const char *path,int bytes)
 107         {
 108         return(-1);
 109         }
 110 #else
 111 #include <openssl/opensslconf.h>
 112 #include OPENSSL_UNISTD
 113 #include <sys/types.h>
 114 #include <sys/socket.h>
 115 #include <sys/un.h>
 116 #include <string.h>
 117 #include <errno.h>
 118
 119 #ifndef offsetof
 120 #  define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 121 #endif
 122
 123 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
 124         {
 125         int ret = 0;
 126         struct sockaddr_un addr;
 127         int len, num, numbytes;
 128         int fd = -1;
 129         int success;
 130         unsigned char egdbuf[2], tempbuf[255], *retrievebuf;
 131
 132         memset(&addr, 0, sizeof(addr));
 133         addr.sun_family = AF_UNIX;
 134         if (strlen(path) > sizeof(addr.sun_path))
 135                 return (-1);
 136         strcpy(addr.sun_path,path);
 137         len = offsetof(struct sockaddr_un, sun_path) + strlen(path);
 138         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 139         if (fd == -1) return (-1);
 140         success = 0;
 141         while (!success)
 142             {
 143             if (connect(fd, (struct sockaddr *)&addr, len) == 0)
 144                success = 1;
 145             else
 146                 {
 147                 switch (errno)
 148                     {
 149 #ifdef EINTR
 150                     case EINTR:
 151 #endif
 152 #ifdef EAGAIN
 153                     case EAGAIN:
 154 #endif
 155 #ifdef EINPROGRESS
 156                     case EINPROGRESS:
 157 #endif
 158 #ifdef EALREADY
 159                     case EALREADY:
 160 #endif
 161                         /* No error, try again */
 162                         break;
 163 #ifdef EISCONN
 164                     case EISCONN:
 165                         success = 1;
 166                         break;
 167 #endif
 168                     default:
 169                         goto err;       /* failure */
 170                     }
 171                 }
 172             }
 173
 174         while(bytes > 0)
 175             {
 176             egdbuf[0] = 1;
 177             egdbuf[1] = bytes < 255 ? bytes : 255;
 178             numbytes = 0;
 179             while (numbytes != 2)
 180                 {
 181                 num = write(fd, egdbuf + numbytes, 2 - numbytes);
 182                 if (num >= 0)
 183                     numbytes += num;
 184                 else
 185                     {
 186                     switch (errno)
 187                         {
 188 #ifdef EINTR
 189                         case EINTR:
 190 #endif
 191 #ifdef EAGAIN
 192                         case EAGAIN:
 193 #endif
 194                             /* No error, try again */
 195                             break;
 196                         default:
 197                             ret = -1;
 198                             goto err;   /* failure */
 199                         }
 200                     }
 201                 }
 202             numbytes = 0;
 203             while (numbytes != 1)
 204                 {
 205                 num = read(fd, egdbuf, 1);
 206                 if (num >= 0)
 207                     numbytes += num;
 208                 else
 209                     {
 210                     switch (errno)
 211                         {
 212 #ifdef EINTR
 213                         case EINTR:
 214 #endif
 215 #ifdef EAGAIN
 216                         case EAGAIN:
 217 #endif
 218                             /* No error, try again */
 219                             break;
 220                         default:
 221                             ret = -1;
 222                             goto err;   /* failure */
 223                         }
 224                     }
 225                 }
 226             if(egdbuf[0] == 0)
 227                 goto err;
 228             if (buf)
 229                 retrievebuf = buf + ret;
 230             else
 231                 retrievebuf = tempbuf;
 232             numbytes = 0;
 233             while (numbytes != egdbuf[0])
 234                 {
 235                 num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes);
 236                 if (num >= 0)
 237                     numbytes += num;
 238                 else
 239                     {
 240                     switch (errno)
 241                         {
 242 #ifdef EINTR
 243                         case EINTR:
 244 #endif
 245 #ifdef EAGAIN
 246                         case EAGAIN:
 247 #endif
 248                             /* No error, try again */
 249                             break;
 250                         default:
 251                             ret = -1;
 252                             goto err;   /* failure */
 253                         }
 254                     }
 255                 }
 256             ret += egdbuf[0];
 257             bytes -= egdbuf[0];
 258             if (!buf)
 259                 RAND_seed(tempbuf, egdbuf[0]);
 260             }
 261  err:
 262         if (fd != -1) close(fd);
 263         return(ret);
 264         }
 265
 266
 267 int RAND_egd_bytes(const char *path, int bytes)
 268         {
 269         int num, ret = 0;
 270
 271         num = RAND_query_egd_bytes(path, NULL, bytes);
 272         if (num < 1) goto err;
 273         if (RAND_status() == 1)
 274             ret = num;
 275  err:
 276         return(ret);
 277         }
 278
 279
 280 int RAND_egd(const char *path)
 281         {
 282         return (RAND_egd_bytes(path, 255));
 283         }
 284
 285
 286 #endif