use the new fat random sysctl to get initial state. (fallback to looping).

stir after eating 400000 words.  ok + input deraadt

src/lib/libc/crypt/arc4random.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: arc4random.c,v 1.11 2004/11/02 11:07:13 hshoexer Exp $	*/
+/*	$OpenBSD: arc4random.c,v 1.12 2005/06/04 05:13:13 tedu Exp $	*/
 
 /*
  * Arc4 random number generator for OpenBSD.
@@ -47,6 +47,7 @@ struct arc4_stream {
 static int rs_initialized;
 static struct arc4_stream rs;
 static pid_t arc4_stir_pid;
+static int arc4_count;
 
 static inline u_int8_t arc4_getbyte(struct arc4_stream *);
 
@@ -83,23 +84,23 @@ arc4_stir(struct arc4_stream *as)
 {
 	int     i, mib[2];
 	size_t	len;
-	struct {
-		struct timeval tv;
-		u_int rnd[(128 - sizeof(struct timeval)) / sizeof(u_int)];
-	}       rdat;
+	u_char rnd[128];
 
-	gettimeofday(&rdat.tv, NULL);
 	mib[0] = CTL_KERN;
 	mib[1] = KERN_ARND;
 
-	for (i = 0; i < sizeof(rdat.rnd) / sizeof(u_int); i ++) {
-		len = sizeof(u_int);
-		if (sysctl(mib, 2, &rdat.rnd[i], &len, NULL, 0) == -1)
-			break;
+	len = sizeof(rnd);
+	if (sysctl(mib, 2, rnd, &len, NULL, 0) == -1) {
+		for (i = 0; i < sizeof(rnd) / sizeof(u_int); i ++) {
+			len = sizeof(u_int);
+			if (sysctl(mib, 2, &rnd[i * sizeof(u_int)], &len,
+			    NULL, 0) == -1)
+				break;
+		}
 	}
 
 	arc4_stir_pid = getpid();
-	arc4_addrandom(as, (void *)&rdat, sizeof(rdat));
+	arc4_addrandom(as, rnd, sizeof(rnd));
 
 	/*
 	 * Discard early keystream, as per recommendations in:
@@ -107,6 +108,7 @@ arc4_stir(struct arc4_stream *as)
 	 */
 	for (i = 0; i < 256; i++)
 		(void)arc4_getbyte(as);
+	arc4_count = 400000;
 }
 
 static inline u_int8_t
@@ -155,7 +157,7 @@ arc4random_addrandom(u_char *dat, int datlen)
 u_int32_t
 arc4random(void)
 {
-	if (!rs_initialized || arc4_stir_pid != getpid())
+	if (--arc4_count == 0 || !rs_initialized || arc4_stir_pid != getpid())
 		arc4random_stir();
 	return arc4_getword(&rs);
 }