Line data    Source code

       1             : /*
       2             :  * Copyright (c) 2006 Kungliga Tekniska Högskolan
       3             :  * (Royal Institute of Technology, Stockholm, Sweden).
       4             :  * 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 the
      15             :  *    documentation and/or other materials provided with the distribution.
      16             :  *
      17             :  * 3. Neither the name of the Institute nor the names of its contributors
      18             :  *    may be used to endorse or promote products derived from this software
      19             :  *    without specific prior written permission.
      20             :  *
      21             :  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
      22             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      23             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      24             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
      25             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      26             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      27             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      28             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      29             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      30             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      31             :  * SUCH DAMAGE.
      32             :  */
      33             : 
      34             : #include <config.h>
      35             : #include <roken.h>
      36             : 
      37             : #include <rand.h>
      38             : #include <heim_threads.h>
      39             : 
      40             : #include "randi.h"
      41             : 
      42             : /*
      43             :  * Unix /dev/random
      44             :  */
      45             : 
      46             : int
      47       37107 : _hc_unix_device_fd(int flags, const char **fn)
      48             : {
      49        1304 :     static const char *rnd_devices[] = {
      50             :         "/dev/urandom",
      51             :         "/dev/random",
      52             :         "/dev/srandom",
      53             :         "/dev/arandom",
      54             :         NULL
      55             :     };
      56        1304 :     const char **p;
      57             : 
      58       37107 :     for(p = rnd_devices; *p; p++) {
      59       37107 :         int fd = open(*p, flags | O_NDELAY);
      60       37107 :         if(fd >= 0) {
      61       37107 :             if (fn)
      62           0 :                 *fn = *p;
      63       37107 :             rk_cloexec(fd);
      64       37107 :             return fd;
      65             :         }
      66             :     }
      67           0 :     return -1;
      68             : }
      69             : 
      70             : static void
      71           0 : unix_seed(const void *p, int size)
      72             : {
      73           0 :     const unsigned char *indata = p;
      74           0 :     ssize_t count;
      75           0 :     int fd;
      76             : 
      77           0 :     if (size < 0)
      78           0 :         return;
      79           0 :     else if (size == 0)
      80           0 :         return;
      81             : 
      82           0 :     fd = _hc_unix_device_fd(O_RDONLY, NULL);
      83           0 :     if (fd < 0)
      84           0 :         return;
      85             : 
      86           0 :     while (size > 0) {
      87           0 :         count = write(fd, indata, size);
      88           0 :         if (count < 0 && errno == EINTR)
      89           0 :             continue;
      90           0 :         else if (count <= 0) {
      91           0 :             close(fd);
      92           0 :             return;
      93             :         }
      94           0 :         indata += count;
      95           0 :         size -= count;
      96             :     }
      97           0 :     close(fd);
      98             : }
      99             : 
     100             : 
     101             : static int
     102       37107 : unix_bytes(unsigned char *outdata, int size)
     103             : {
     104        1304 :     ssize_t count;
     105        1304 :     int fd;
     106             : 
     107       37107 :     if (size < 0)
     108           0 :         return 0;
     109       37107 :     else if (size == 0)
     110           0 :         return 1;
     111             : 
     112       37107 :     fd = _hc_unix_device_fd(O_RDONLY, NULL);
     113       37107 :     if (fd < 0)
     114           0 :         return 0;
     115             : 
     116       74214 :     while (size > 0) {
     117       37107 :         count = read(fd, outdata, size);
     118       37107 :         if (count < 0 && errno == EINTR)
     119           0 :             continue;
     120       37107 :         else if (count <= 0) {
     121           0 :             close(fd);
     122           0 :             return 0;
     123             :         }
     124       37107 :         outdata += count;
     125       37107 :         size -= count;
     126             :     }
     127       37107 :     close(fd);
     128             : 
     129       37107 :     return 1;
     130             : }
     131             : 
     132             : static void
     133           0 : unix_cleanup(void)
     134             : {
     135           0 : }
     136             : 
     137             : static void
     138           0 : unix_add(const void *indata, int size, double entropi)
     139             : {
     140           0 :     unix_seed(indata, size);
     141           0 : }
     142             : 
     143             : static int
     144           0 : unix_pseudorand(unsigned char *outdata, int size)
     145             : {
     146           0 :     return unix_bytes(outdata, size);
     147             : }
     148             : 
     149             : static int
     150           0 : unix_status(void)
     151             : {
     152           0 :     int fd;
     153             : 
     154           0 :     fd = _hc_unix_device_fd(O_RDONLY, NULL);
     155           0 :     if (fd < 0)
     156           0 :         return 0;
     157           0 :     close(fd);
     158             : 
     159           0 :     return 1;
     160             : }
     161             : 
     162             : const RAND_METHOD hc_rand_unix_method = {
     163             :     unix_seed,
     164             :     unix_bytes,
     165             :     unix_cleanup,
     166             :     unix_add,
     167             :     unix_pseudorand,
     168             :     unix_status
     169             : };
     170             : 
     171             : const RAND_METHOD *
     172           0 : RAND_unix_method(void)
     173             : {
     174           0 :     return &hc_rand_unix_method;
     175             : }