Create a suspend/resume infrastructure for the RNG. At suspend time,

process all queued entropy and create a brand new pool to prevent
backtracking upon resume.  At resume time, process the entropy queue
(since other resume code paths which run earlier can enqueue entropy)
and force all higher to reseed.
ok reyk djm

diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c
index 0fa701a..b14470e 100644 (file)
--- a/sys/dev/rnd.c
+++ b/sys/dev/rnd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rnd.c,v 1.163 2014/10/24 20:02:07 tedu Exp $  */
+/*     $OpenBSD: rnd.c,v 1.164 2014/12/18 16:27:30 deraadt Exp $       */
 
 /*
  * Copyright (c) 2011 Theo de Raadt.
@@ -548,6 +548,33 @@ static u_char rs_buf[RSBUFSZ] __attribute__((section(".openbsd.randomdata")));
 static size_t rs_have;         /* valid bytes at end of rs_buf */
 static size_t rs_count;                /* bytes till reseed */
 
+void
+suspend_randomness(void)
+{
+       struct timespec ts;
+
+       getnanotime(&ts);
+       add_true_randomness(ts.tv_sec);
+       add_true_randomness(ts.tv_nsec);
+
+       dequeue_randomness(NULL);
+       rs_count = 0;
+       arc4random_buf(entropy_pool, sizeof(entropy_pool));
+}
+
+void
+resume_randomness(void)
+{
+       struct timespec ts;
+
+       getnanotime(&ts);
+       add_true_randomness(ts.tv_sec);
+       add_true_randomness(ts.tv_nsec);
+
+       dequeue_randomness(NULL);
+       rs_count = 0;
+}
+
 static inline void _rs_rekey(u_char *dat, size_t datlen);
 
 static inline void

diff --git a/sys/dev/rndvar.h b/sys/dev/rndvar.h
index 5907e26..8f68e2a 100644 (file)
--- a/sys/dev/rndvar.h
+++ b/sys/dev/rndvar.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: rndvar.h,v 1.34 2014/11/18 02:37:30 tedu Exp $        */
+/*     $OpenBSD: rndvar.h,v 1.35 2014/12/18 16:27:30 deraadt Exp $     */
 
 /*
  * Copyright (c) 1996,2000 Michael Shalayeff.
@@ -72,6 +72,8 @@ extern struct rndstats rndstats;
 void random_start(void);
 
 void enqueue_randomness(int, int);
+void suspend_randomness(void);
+void resume_randomness(void);
 
 #endif /* _KERNEL */