Use arc4random_uniform() insead of rand() and modulus.

OK deraadt@

2 files changed, 7 insertions, 10 deletions

diff --git a/games/cribbage/cards.c b/games/cribbage/cards.c
index f27a4febdcd..26aae894600 100644
--- a/games/cribbage/cards.c
+++ b/games/cribbage/cards.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cards.c,v 1.5 2009/10/27 23:59:24 deraadt Exp $	*/
+/*	$OpenBSD: cards.c,v 1.6 2013/10/25 18:31:29 millert Exp $	*/
 /*	$NetBSD: cards.c,v 1.3 1995/03/21 15:08:41 cgd Exp $	*/
 
 /*-
@@ -47,9 +47,6 @@ makedeck(CARD d[])
 {
 	int i, j, k;
 
-	i = time(NULL);
-	i = ((i & 0xff) << 8) | ((i >> 8) & 0xff) | 1;
-	srand(i);
 	k = 0;
 	for (i = 0; i < RANKS; i++)
 		for (j = 0; j < SUITS; j++) {
@@ -69,7 +66,7 @@ shuffle(CARD d[])
 	CARD c;
 
 	for (j = CARDS; j > 0; --j) {
-		k = (rand() >> 4) % j;		/* random 0 <= k < j */
+		k = arc4random_uniform(j);	/* random 0 <= k < j */
 		c = d[j - 1];			/* exchange (j - 1) and k */
 		d[j - 1] = d[k];
 		d[k] = c;
diff --git a/games/cribbage/crib.c b/games/cribbage/crib.c
index b6d9970d706..7503fabf33f 100644
--- a/games/cribbage/crib.c
+++ b/games/cribbage/crib.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: crib.c,v 1.16 2012/03/04 04:05:15 fgsch Exp $	*/
+/*	$OpenBSD: crib.c,v 1.17 2013/10/25 18:31:29 millert Exp $	*/
 /*	$NetBSD: crib.c,v 1.7 1997/07/10 06:47:29 mikel Exp $	*/
 
 /*-
@@ -214,9 +214,9 @@ game(void)
 						*foo = '\0';
 				} while (*foo != '\0');
 			}
-			i = (rand() >> 4) % CARDS;	/* random cut */
+			i = arc4random_uniform(CARDS);	/* random cut */
 			do {	/* comp cuts deck */
-				j = (rand() >> 4) % CARDS;
+				j = arc4random_uniform(CARDS);
 			} while (j == i);
 			addmsg(quiet ? "You cut " : "You cut the ");
 			msgcard(deck[i], FALSE);
@@ -396,7 +396,7 @@ cut(bool mycrib, int pos)
 					*foo = '\0';
 			} while (*foo != '\0');
 		}
-		i = (rand() >> 4) % (CARDS - pos);
+		i = arc4random_uniform(CARDS - pos);
 		turnover = deck[i + pos];
 		addmsg(quiet ? "You cut " : "You cut the ");
 		msgcard(turnover, FALSE);
@@ -407,7 +407,7 @@ cut(bool mycrib, int pos)
 			win = chkscr(&cscore, 2);
 		}
 	} else {
-		i = (rand() >> 4) % (CARDS - pos) + pos;
+		i = arc4random_uniform(CARDS - pos) + pos;
 		turnover = deck[i];
 		addmsg(quiet ? "I cut " : "I cut the ");
 		msgcard(turnover, FALSE);