tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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uxrng.c (2506B)

      1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 #include "primpl.h"
      7 
      8 #include <string.h>
      9 #include <unistd.h>
     10 #include <errno.h>
     11 #include <sys/time.h>
     12 
     13 #if defined(SOLARIS)
     14 
     15 static size_t GetHighResClock(void* buf, size_t maxbytes) {
     16  hrtime_t t;
     17  t = gethrtime();
     18  if (t) {
     19    return _pr_CopyLowBits(buf, maxbytes, &t, sizeof(t));
     20  }
     21  return 0;
     22 }
     23 
     24 #elif defined(AIX)
     25 
     26 static size_t GetHighResClock(void* buf, size_t maxbytes) { return 0; }
     27 
     28 #elif (defined(LINUX) || defined(FREEBSD) || defined(__FreeBSD_kernel__) || \
     29       defined(NETBSD) || defined(__NetBSD_kernel__) || defined(OPENBSD) || \
     30       defined(__GNU__))
     31 #  include <sys/types.h>
     32 #  include <sys/stat.h>
     33 #  include <fcntl.h>
     34 
     35 static int fdDevURandom;
     36 static PRCallOnceType coOpenDevURandom;
     37 
     38 static PRStatus OpenDevURandom(void) {
     39  fdDevURandom = open("/dev/urandom", O_RDONLY);
     40  return ((-1 == fdDevURandom) ? PR_FAILURE : PR_SUCCESS);
     41 } /* end OpenDevURandom() */
     42 
     43 static size_t GetDevURandom(void* buf, size_t size) {
     44  int bytesIn;
     45  int rc;
     46 
     47  rc = PR_CallOnce(&coOpenDevURandom, OpenDevURandom);
     48  if (PR_FAILURE == rc) {
     49    _PR_MD_MAP_OPEN_ERROR(errno);
     50    return (0);
     51  }
     52 
     53  bytesIn = read(fdDevURandom, buf, size);
     54  if (-1 == bytesIn) {
     55    _PR_MD_MAP_READ_ERROR(errno);
     56    return (0);
     57  }
     58 
     59  return (bytesIn);
     60 } /* end GetDevURandom() */
     61 
     62 static size_t GetHighResClock(void* buf, size_t maxbytes) {
     63  return (GetDevURandom(buf, maxbytes));
     64 }
     65 
     66 #elif defined(NTO) || defined(QNX) || defined(DARWIN) || defined(RISCOS)
     67 #  include <sys/times.h>
     68 
     69 static size_t GetHighResClock(void* buf, size_t maxbytes) {
     70  int ticks;
     71  struct tms buffer;
     72 
     73  ticks = times(&buffer);
     74  return _pr_CopyLowBits(buf, maxbytes, &ticks, sizeof(ticks));
     75 }
     76 #else
     77 #  error ! Platform undefined
     78 #endif /* defined(SOLARIS) */
     79 
     80 extern PRSize _PR_MD_GetRandomNoise(void* buf, PRSize size) {
     81  struct timeval tv;
     82  int n = 0;
     83  int s;
     84 
     85  n += GetHighResClock(buf, size);
     86  size -= n;
     87 
     88  GETTIMEOFDAY(&tv);
     89 
     90  if (size > 0) {
     91    s = _pr_CopyLowBits((char*)buf + n, size, &tv.tv_usec, sizeof(tv.tv_usec));
     92    size -= s;
     93    n += s;
     94  }
     95  if (size > 0) {
     96    s = _pr_CopyLowBits((char*)buf + n, size, &tv.tv_sec, sizeof(tv.tv_usec));
     97    size -= s;
     98    n += s;
     99  }
    100 
    101  return n;
    102 } /* end _PR_MD_GetRandomNoise() */