 @@ -1,14 +1,14 @@
-/*	$NetBSD: arc4random.c,v 1.12 2012/03/04 00:36:43 tls Exp $	*/
+/*	$NetBSD: arc4random.c,v 1.13 2012/03/05 19:40:08 christos Exp $	*/
 /*	$OpenBSD: arc4random.c,v 1.6 2001/06/05 05:05:38 pvalchev Exp $	*/
 /*
  * Arc4 random number generator for OpenBSD.
  * Copyright 1996 David Mazieres <dm@lcs.mit.edu>.
+ *
  * Modification and redistribution in source and binary forms is
  * permitted provided that due credit is given to the author and the
  * OpenBSD project by leaving this copyright notice intact.
  */
 /*
  * This code is derived from section 17.1 of Applied Cryptography,
 @@ -17,126 +17,119 @@
  * which is a trade secret).  The same algorithm is used as a stream
  * cipher called "arcfour" in Tatu Ylonen's ssh package.
+ *
  * Here the stream cipher has been modified always to include the time
  * when initializing the state.  That makes it impossible to
  * regenerate the same random sequence twice, so this can't be used
  * for encryption, but will generate good random numbers.
+ *
  * RC4 is a registered trademark of RSA Laboratories.
  */
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: arc4random.c,v 1.12 2012/03/04 00:36:43 tls Exp $");
+__RCSID("$NetBSD: arc4random.c,v 1.13 2012/03/05 19:40:08 christos Exp $");
 #endif /* LIBC_SCCS and not lint */
 #include "namespace.h"
 #include "reentrant.h"
 #include <fcntl.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/sysctl.h>
 #ifdef __weak_alias
 __weak_alias(arc4random,_arc4random)
 #endif
 #define RSIZE 256
 struct arc4_stream {
 	mutex_t mtx;
 	int initialized;
 	uint8_t i;
 	uint8_t j;
-	uint8_t s[256];
+	uint8_t s[RSIZE];
 };
 /* XXX lint explodes with an internal error if only mtx is initialized! */
 static struct arc4_stream rs = { .i = 0, .mtx = MUTEX_INITIALIZER };
 static inline void arc4_init(struct arc4_stream *);
 static inline void arc4_addrandom(struct arc4_stream *, u_char *, int);
 static void arc4_stir(struct arc4_stream *);
 static inline uint8_t arc4_getbyte(struct arc4_stream *);
 static inline uint32_t arc4_getword(struct arc4_stream *);
 static inline void
 arc4_init(struct arc4_stream *as)
+{
-	int     n;
+	for (int n = 0; n < RSIZE; n++)
 	for (n = 0; n < 256; n++)
 		as->s[n] = n;
 	as->i = 0;
 	as->j = 0;
 	as->initialized = 1;
 	arc4_stir(as);
+}
 static inline void
 arc4_addrandom(struct arc4_stream *as, u_char *dat, int datlen)
+{
 	int     n;
 	uint8_t si;
 	as->i--;
-	for (n = 0; n < 256; n++) {
+	for (int n = 0; n < RSIZE; n++) {
 		as->i = (as->i + 1);
 		si = as->s[as->i];
 		as->j = (as->j + si + dat[n % datlen]);
 		as->s[as->i] = as->s[as->j];
 		as->s[as->j] = si;
+	}
 	as->j = as->i;
+}
 static void
 arc4_stir(struct arc4_stream *as)
+{
-	int rdat[128 / sizeof(int)];
+	int rdat[32];
-	int	n;
+	static const int mib[] = { CTL_KERN, KERN_URND };
 	int mib[2];
 	unsigned int i;
 	size_t len;
 	/*
 	 * This code once opened and read /dev/urandom on each
 	 * call.  That causes repeated rekeying of the kernel stream
 	 * generator, which is very wasteful.  Because of application
 	 * behavior, caching the fd doesn't really help.  So we just
 	 * fill up the tank from sysctl, which is a tiny bit slower
 	 * for us but much friendlier to other entropy consumers.
 	 */
-	mib[0] = CTL_KERN;
+	for (size_t i = 0; i < __arraycount(rdat); i++) {
 	mib[1] = KERN_URND;
 	for (i = 0; i < sizeof(rdat) / sizeof(int); i++) {
 		len = sizeof(rdat[i]);
 		if (sysctl(mib, 2, &rdat[i], &len, NULL, 0) == -1)
 			abort();
+	}
-	arc4_addrandom(as, (void *) &rdat, sizeof(rdat));
+	arc4_addrandom(as, (void *) &rdat, (int)sizeof(rdat));
 	/*
 	 * Throw away the first N words of output, as suggested in the
 	 * paper "Weaknesses in the Key Scheduling Algorithm of RC4"
 	 * by Fluher, Mantin, and Shamir.  (N = 256 in our case.)
 	 */
-	for (n = 0; n < 256 * 4; n++)
+	for (size_t j = 0; j < RSIZE * 4; j++)
 		arc4_getbyte(as);
+}
 static inline uint8_t
 arc4_getbyte(struct arc4_stream *as)
+{
 	uint8_t si, sj;
 	as->i = (as->i + 1);
 	si = as->s[as->i];
 	as->j = (as->j + si);
 	sj = as->s[as->j];
 	as->s[as->i] = sj;
 @@ -274,27 +267,27 @@ arc4random_buf(void *buf, size_t len)
  * random number will be inside the range
  * [2^32 % upper_bound, 2^32[ which maps back to
  * [0, upper_bound[ after reduction modulo upper_bound.
  */
 static uint32_t
 _arc4random_uniform_unlocked(uint32_t upper_bound)
+{
 	uint32_t r, min;
 	if (upper_bound < 2)
 		return 0;
 #if defined(ULONG_MAX) && (ULONG_MAX > 0xFFFFFFFFUL)
-	min = 0x100000000UL % upper_bound;
+	min = (uint32_t)(0x100000000U % upper_bound);
 #else
 	/* calculate (2^32 % upper_bound) avoiding 64-bit math */
 	if (upper_bound > 0x80000000U)
 		/* 2^32 - upper_bound (only one "value area") */
 		min = 1 + ~upper_bound;
 	else
 		/* ((2^32 - x) % x) == (2^32 % x) when x <= 2^31 */
 		min = (0xFFFFFFFFU - upper_bound + 1) % upper_bound;
 #endif
 	/*
 	 * This could theoretically loop forever but each retry has
 	 * p > 0.5 (worst case, usually far better) of selecting a