; Auto-commit of loaddefs files.

[gnu-emacs] / src / sysdep.c

diff --git a/src/sysdep.c b/src/sysdep.c
index 1af323eb8d6e441181b424de50a19cb6322b8535..460166d119eb1ad8474894d3a85e40c34bb7d522 100644 (file)
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1,13 +1,13 @@
 /* Interfaces to system-dependent kernel and library entries.
-   Copyright (C) 1985-1988, 1993-1995, 1999-2015 Free Software
+   Copyright (C) 1985-1988, 1993-1995, 1999-2016 Free Software
    Foundation, Inc.
 
 This file is part of GNU Emacs.
 
 GNU Emacs is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
 
 GNU Emacs is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -99,6 +99,16 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "process.h"
 #include "cm.h"
 
+#include "gnutls.h"
+/* MS-Windows loads GnuTLS at run time, if available; we don't want to
+   do that during startup just to call gnutls_rnd.  */
+#if 0x020c00 <= GNUTLS_VERSION_NUMBER && !defined WINDOWSNT
+# include <gnutls/crypto.h>
+#else
+# define emacs_gnutls_global_init() Qnil
+# define gnutls_rnd(level, data, len) (-1)
+#endif
+
 #ifdef WINDOWSNT
 #include <direct.h>
 /* In process.h which conflicts with the local copy.  */
@@ -2068,36 +2078,56 @@ init_signals (bool dumping)
 # endif /* !HAVE_RANDOM */
 #endif /* !RAND_BITS */
 
+#ifdef HAVE_RANDOM
+typedef unsigned int random_seed;
+static void set_random_seed (random_seed arg) { srandom (arg); }
+#elif defined HAVE_LRAND48
+/* Although srand48 uses a long seed, this is unsigned long to avoid
+   undefined behavior on signed integer overflow in init_random.  */
+typedef unsigned long int random_seed;
+static void set_random_seed (random_seed arg) { srand48 (arg); }
+#else
+typedef unsigned int random_seed;
+static void set_random_seed (random_seed arg) { srand (arg); }
+#endif
+
 void
 seed_random (void *seed, ptrdiff_t seed_size)
 {
-#if defined HAVE_RANDOM || ! defined HAVE_LRAND48
-  unsigned int arg = 0;
-#else
-  long int arg = 0;
-#endif
+  random_seed arg = 0;
   unsigned char *argp = (unsigned char *) &arg;
   unsigned char *seedp = seed;
-  ptrdiff_t i;
-  for (i = 0; i < seed_size; i++)
+  for (ptrdiff_t i = 0; i < seed_size; i++)
     argp[i % sizeof arg] ^= seedp[i];
-#ifdef HAVE_RANDOM
-  srandom (arg);
-#else
-# ifdef HAVE_LRAND48
-  srand48 (arg);
-# else
-  srand (arg);
-# endif
-#endif
+  set_random_seed (arg);
 }
 
 void
 init_random (void)
 {
-  struct timespec t = current_timespec ();
-  uintmax_t v = getpid () ^ t.tv_sec ^ t.tv_nsec;
-  seed_random (&v, sizeof v);
+  random_seed v;
+  if (! (EQ (emacs_gnutls_global_init (), Qt)
+        && gnutls_rnd (GNUTLS_RND_NONCE, &v, sizeof v) == 0))
+    {
+      bool success = false;
+#ifndef WINDOWSNT
+      int fd = emacs_open ("/dev/urandom", O_RDONLY | O_BINARY, 0);
+      if (0 <= fd)
+       {
+         success = emacs_read (fd, &v, sizeof v) == sizeof v;
+         emacs_close (fd);
+       }
+#else
+      success = w32_init_random (&v, sizeof v) == 0;
+#endif
+      if (! success)
+       {
+         /* Fall back to current time value + PID.  */
+         struct timespec t = current_timespec ();
+         v = getpid () ^ t.tv_sec ^ t.tv_nsec;
+       }
+    }
+  set_random_seed (v);
 }
 
 /*