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/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 occured 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 occured 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 #if defined(OPENSSL_SYS_WIN32) || defined(VMS) || defined(__VMS)
  98 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
  99         {
 100         return(-1);
 101         }
 102 int RAND_egd(const char *path)
 103         {
 104         return(-1);
 105         }
 106
 107 int RAND_egd_bytes(const char *path,int bytes)
 108         {
 109         return(-1);
 110         }
 111 #else
 112 #include <openssl/opensslconf.h>
 113 #include OPENSSL_UNISTD
 114 #include <sys/types.h>
 115 #include <sys/socket.h>
 116 #ifndef NO_SYS_UN_H
 117 #include <sys/un.h>
 118 #else
 119 struct  sockaddr_un {
 120         short   sun_family;             /* AF_UNIX */
 121         char    sun_path[108];          /* path name (gag) */
 122 };
 123 #endif /* NO_SYS_UN_H */
 124 #include <string.h>
 125 #include <errno.h>
 126
 127 #ifndef offsetof
 128 #  define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
 129 #endif
 130
 131 int RAND_query_egd_bytes(const char *path, unsigned char *buf, int bytes)
 132         {
 133         int ret = 0;
 134         struct sockaddr_un addr;
 135         int len, num, numbytes;
 136         int fd = -1;
 137         int success;
 138         unsigned char egdbuf[2], tempbuf[255], *retrievebuf;
 139
 140         memset(&addr, 0, sizeof(addr));
 141         addr.sun_family = AF_UNIX;
 142         if (strlen(path) > sizeof(addr.sun_path))
 143                 return (-1);
 144         strcpy(addr.sun_path,path);
 145         len = offsetof(struct sockaddr_un, sun_path) + strlen(path);
 146         fd = socket(AF_UNIX, SOCK_STREAM, 0);
 147         if (fd == -1) return (-1);
 148         success = 0;
 149         while (!success)
 150             {
 151             if (connect(fd, (struct sockaddr *)&addr, len) == 0)
 152                success = 1;
 153             else
 154                 {
 155                 switch (errno)
 156                     {
 157 #ifdef EINTR
 158                     case EINTR:
 159 #endif
 160 #ifdef EAGAIN
 161                     case EAGAIN:
 162 #endif
 163 #ifdef EINPROGRESS
 164                     case EINPROGRESS:
 165 #endif
 166 #ifdef EALREADY
 167                     case EALREADY:
 168 #endif
 169                         /* No error, try again */
 170                         break;
 171 #ifdef EISCONN
 172                     case EISCONN:
 173                         success = 1;
 174                         break;
 175 #endif
 176                     default:
 177                         goto err;       /* failure */
 178                     }
 179                 }
 180             }
 181
 182         while(bytes > 0)
 183             {
 184             egdbuf[0] = 1;
 185             egdbuf[1] = bytes < 255 ? bytes : 255;
 186             numbytes = 0;
 187             while (numbytes != 2)
 188                 {
 189                 num = write(fd, egdbuf + numbytes, 2 - numbytes);
 190                 if (num >= 0)
 191                     numbytes += num;
 192                 else
 193                     {
 194                     switch (errno)
 195                         {
 196 #ifdef EINTR
 197                         case EINTR:
 198 #endif
 199 #ifdef EAGAIN
 200                         case EAGAIN:
 201 #endif
 202                             /* No error, try again */
 203                             break;
 204                         default:
 205                             ret = -1;
 206                             goto err;   /* failure */
 207                         }
 208                     }
 209                 }
 210             numbytes = 0;
 211             while (numbytes != 1)
 212                 {
 213                 num = read(fd, egdbuf, 1);
 214                 if (num >= 0)
 215                     numbytes += num;
 216                 else
 217                     {
 218                     switch (errno)
 219                         {
 220 #ifdef EINTR
 221                         case EINTR:
 222 #endif
 223 #ifdef EAGAIN
 224                         case EAGAIN:
 225 #endif
 226                             /* No error, try again */
 227                             break;
 228                         default:
 229                             ret = -1;
 230                             goto err;   /* failure */
 231                         }
 232                     }
 233                 }
 234             if(egdbuf[0] == 0)
 235                 goto err;
 236             if (buf)
 237                 retrievebuf = buf + ret;
 238             else
 239                 retrievebuf = tempbuf;
 240             numbytes = 0;
 241             while (numbytes != egdbuf[0])
 242                 {
 243                 num = read(fd, retrievebuf + numbytes, egdbuf[0] - numbytes);
 244                 if (num >= 0)
 245                     numbytes += num;
 246                 else
 247                     {
 248                     switch (errno)
 249                         {
 250 #ifdef EINTR
 251                         case EINTR:
 252 #endif
 253 #ifdef EAGAIN
 254                         case EAGAIN:
 255 #endif
 256                             /* No error, try again */
 257                             break;
 258                         default:
 259                             ret = -1;
 260                             goto err;   /* failure */
 261                         }
 262                     }
 263                 }
 264             ret += egdbuf[0];
 265             bytes -= egdbuf[0];
 266             if (!buf)
 267                 RAND_seed(tempbuf, egdbuf[0]);
 268             }
 269  err:
 270         if (fd != -1) close(fd);
 271         return(ret);
 272         }
 273
 274
 275 int RAND_egd_bytes(const char *path, int bytes)
 276         {
 277         int num, ret = 0;
 278
 279         num = RAND_query_egd_bytes(path, NULL, bytes);
 280         if (num < 1) goto err;
 281         if (RAND_status() == 1)
 282             ret = num;
 283  err:
 284         return(ret);
 285         }
 286
 287
 288 int RAND_egd(const char *path)
 289         {
 290         return (RAND_egd_bytes(path, 255));
 291         }
 292
 293
 294 #endif