X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/b3f050848e5d285c2a1d7f8a4bea98984c201805..813390c45f438f411662b1a55678e63f11681eb4:/noise.h

diff --git a/noise.h b/noise.h
index d335448..48fe6bd 100644
--- a/noise.h
+++ b/noise.h
@@ -1,13 +1,13 @@
 /* -*-c-*-
  *
- * $Id: noise.h,v 1.2 1999/12/10 23:29:48 mdw Exp $
+ * $Id: noise.h,v 1.6 2004/04/08 01:36:15 mdw Exp $
  *
- * Acquisition of environmental noise (Unix specific)
+ * Acquisition of environmental noise (Unix-specific)
  *
  * (c) 1998 Straylight/Edgeware
  */
 
-/*----- Licensing notice --------------------------------------------------* 
+/*----- Licensing notice --------------------------------------------------*
  *
  * This file is part of Catacomb.
  *
@@ -15,29 +15,18 @@
  * it under the terms of the GNU Library General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
- * 
+ *
  * Catacomb is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Library General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Library General Public
  * License along with Catacomb; if not, write to the Free
  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  * MA 02111-1307, USA.
  */
 
-/*----- Revision history --------------------------------------------------* 
- *
- * $Log: noise.h,v $
- * Revision 1.2  1999/12/10 23:29:48  mdw
- * Change header file guard names.
- *
- * Revision 1.1  1999/09/03 08:41:12  mdw
- * Initial import.
- *
- */
-
 #ifndef CATACOMB_NOISE_H
 #define CATACOMB_NOISE_H
 
@@ -55,7 +44,7 @@
 
 /*----- Noise source definition -------------------------------------------*/
 
-extern rand_source noise_source;
+extern const rand_source noise_source;
 
 /*----- Magic numbers -----------------------------------------------------*/
 
@@ -100,7 +89,7 @@ extern int noise_devrandom(rand_pool */*r*/);
  * Use:		Sets the user and group ids to be used by @noise_filter@
  *		when running child processes.  This is useful to avoid
  *		giving shell commands (even carefully written ones) undue
- *		privileges.
+ *		privileges.  This interface is Unix-specific.
  */
 
 extern void noise_setid(uid_t /*uid*/, gid_t /*gid*/);
@@ -124,10 +113,38 @@ extern void noise_setid(uid_t /*uid*/, gid_t /*gid*/);
  *		fails to complete within a short time period, it is killed.
  *		Paranoid use of close-on-exec flags for file descriptors is
  *		recommended.
+ *
+ *		This interface is Unix-specific.
  */
 
 extern int noise_filter(rand_pool */*r*/, int /*good*/, const char */*c*/);
 
+/* --- @noise_freewheel@ --- *
+ *
+ * Arguments:	@rand_pool *r@ = pointer to a randomness pool
+ *
+ * Returns:	Nonzero if some randomness was contributed.
+ *
+ * Use:		Runs a free counter for a short while as a desparate attempt
+ *		to get randomness from somewhere.  This is actually quite
+ *		effective.
+ */
+
+int noise_freewheel(rand_pool */*r*/);
+
+/* --- @noise_enquire@ --- *
+ *
+ * Arguments:	@rand_pool *r@ = pointer to a randomness pool
+ *
+ * Returns:	Nonzero if some randomness was contributed.
+ *
+ * Use:		Runs some shell commands to enquire about the prevailing
+ *		environment.  This can gather quite a lot of low-quality
+ *		entropy.
+ */
+
+extern int noise_enquire(rand_pool */*r*/);
+
 /* --- @noise_acquire@ --- *
  *
  * Arguments:	@rand_pool *r@ = pointer to a randomness pool