Attachment 3608 Details for Bug 3467 – Split arc4random_uniform out into its own file.

[patch] Split arc4random_uniform out into its own file.

openssh-arc4random_uniform.patch (text/plain), 4.52 KB, created by Darren Tucker on 2022-08-05 13:48:59 AEST

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Creator: Darren Tucker

Created: 2022-08-05 13:48:59 AEST

Size: 4.52 KB

patch

obsolete

>diff --git a/openbsd-compat/Makefile.in b/openbsd-compat/Makefile.in
>index cebe4fe4..016f493e 100644
>--- a/openbsd-compat/Makefile.in
>+++ b/openbsd-compat/Makefile.in
>@@ -17,7 +17,9 @@ INSTALL=@INSTALL@
> LDFLAGS=-L. @LDFLAGS@
> LDFLAGS_NOPIE=-L. -Lopenbsd-compat/ @LDFLAGS_NOPIE@
> 
>-OPENBSD=base64.o \
>+OPENBSD=arc4random.o \
>+	arc4random_uniform.o \
>+	base64.o \
> 	basename.o \
> 	bcrypt_pbkdf.o \
> 	bindresvport.o \
>@@ -64,8 +66,7 @@ OPENBSD=base64.o \
> 	timingsafe_bcmp.o \
> 	vis.o
> 
>-COMPAT=	arc4random.o \
>-	bsd-asprintf.o \
>+COMPAT= bsd-asprintf.o \
> 	bsd-closefrom.o \
> 	bsd-cygwin_util.o \
> 	bsd-err.o \
>diff --git a/openbsd-compat/arc4random.c b/openbsd-compat/arc4random.c
>index f43b5c7c..c218a441 100644
>--- a/openbsd-compat/arc4random.c
>+++ b/openbsd-compat/arc4random.c
>@@ -233,44 +233,6 @@ arc4random_buf(void *_buf, size_t n)
> }
> #endif /* !defined(HAVE_ARC4RANDOM_BUF) && defined(HAVE_ARC4RANDOM) */
> 
>-#ifndef HAVE_ARC4RANDOM_UNIFORM
>-/*
>- * Calculate a uniformly distributed random number less than upper_bound
>- * avoiding "modulo bias".
>- *
>- * Uniformity is achieved by generating new random numbers until the one
>- * returned is outside the range [0, 2**32 % upper_bound).  This
>- * guarantees the selected random number will be inside
>- * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
>- * after reduction modulo upper_bound.
>- */
>-u_int32_t
>-arc4random_uniform(u_int32_t upper_bound)
>-{
>-	u_int32_t r, min;
>-
>-	if (upper_bound < 2)
>-		return 0;
>-
>-	/* 2**32 % x == (2**32 - x) % x */
>-	min = -upper_bound % upper_bound;
>-
>-	/*
>-	 * This could theoretically loop forever but each retry has
>-	 * p > 0.5 (worst case, usually far better) of selecting a
>-	 * number inside the range we need, so it should rarely need
>-	 * to re-roll.
>-	 */
>-	for (;;) {
>-		r = arc4random();
>-		if (r >= min)
>-			break;
>-	}
>-
>-	return r % upper_bound;
>-}
>-#endif /* !HAVE_ARC4RANDOM_UNIFORM */
>-
> #if 0
> /*-------- Test code for i386 --------*/
> #include <stdio.h>
>diff --git a/openbsd-compat/arc4random_uniform.c b/openbsd-compat/arc4random_uniform.c
>new file mode 100644
>index 00000000..1dfec8f6
>--- /dev/null
>+++ b/openbsd-compat/arc4random_uniform.c
>@@ -0,0 +1,64 @@
>+/* OPENBSD ORIGINAL: lib/libc/crypt/arc4random_uniform.c */
>+
>+/*	$OpenBSD: arc4random_uniform.c,v 1.3 2019/01/20 02:59:07 bcook Exp $	*/
>+
>+/*
>+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
>+ *
>+ * Permission to use, copy, modify, and distribute this software for any
>+ * purpose with or without fee is hereby granted, provided that the above
>+ * copyright notice and this permission notice appear in all copies.
>+ *
>+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
>+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
>+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
>+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
>+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
>+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
>+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
>+ */
>+
>+#include "includes.h"
>+
>+#include <stdint.h>
>+#ifdef HAVE_STDINT_H
>+# include <stdlib.h>
>+#endif
>+
>+#ifndef HAVE_ARC4RANDOM_UNIFORM
>+/*
>+ * Calculate a uniformly distributed random number less than upper_bound
>+ * avoiding "modulo bias".
>+ *
>+ * Uniformity is achieved by generating new random numbers until the one
>+ * returned is outside the range [0, 2**32 % upper_bound).  This
>+ * guarantees the selected random number will be inside
>+ * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
>+ * after reduction modulo upper_bound.
>+ */
>+uint32_t
>+arc4random_uniform(uint32_t upper_bound)
>+{
>+	uint32_t r, min;
>+
>+	if (upper_bound < 2)
>+		return 0;
>+
>+	/* 2**32 % x == (2**32 - x) % x */
>+	min = -upper_bound % upper_bound;
>+
>+	/*
>+	 * This could theoretically loop forever but each retry has
>+	 * p > 0.5 (worst case, usually far better) of selecting a
>+	 * number inside the range we need, so it should rarely need
>+	 * to re-roll.
>+	 */
>+	for (;;) {
>+		r = arc4random();
>+		if (r >= min)
>+			break;
>+	}
>+
>+	return r % upper_bound;
>+}
>+#endif /* !HAVE_ARC4RANDOM_UNIFORM */
>diff --git a/openbsd-compat/openbsd-compat.h b/openbsd-compat/openbsd-compat.h
>index 93efff2f..1835a9a5 100644
>--- a/openbsd-compat/openbsd-compat.h
>+++ b/openbsd-compat/openbsd-compat.h
>@@ -232,7 +232,7 @@ void arc4random_buf(void *, size_t);
> #endif
> 
> #ifndef HAVE_ARC4RANDOM_UNIFORM
>-u_int32_t arc4random_uniform(u_int32_t);
>+uint32_t arc4random_uniform(uint32_t);
> #endif
> 
> #ifndef HAVE_ASPRINTF

Flags:

djm: ok+

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