From owner-svn-src-head@freebsd.org Sun Aug 14 23:38:52 2016 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C6413BB99B9; Sun, 14 Aug 2016 23:38:52 +0000 (UTC) (envelope-from delphij@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8A2C91DC8; Sun, 14 Aug 2016 23:38:52 +0000 (UTC) (envelope-from delphij@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u7ENcpJ7048187; Sun, 14 Aug 2016 23:38:51 GMT (envelope-from delphij@FreeBSD.org) Received: (from delphij@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u7ENcpiY048179; Sun, 14 Aug 2016 23:38:51 GMT (envelope-from delphij@FreeBSD.org) Message-Id: <201608142338.u7ENcpiY048179@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: delphij set sender to delphij@FreeBSD.org using -f From: Xin LI Date: Sun, 14 Aug 2016 23:38:51 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304106 - in head: include lib/libc/string X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Aug 2016 23:38:52 -0000 Author: delphij Date: Sun Aug 14 23:38:50 2016 New Revision: 304106 URL: https://svnweb.freebsd.org/changeset/base/304106 Log: Add timingsafe_bcmp and timingsafe_memcmp. Obtained from: OpenBSD Reviewed by: trasz MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D7280 Added: head/lib/libc/string/timingsafe_bcmp.3 (contents, props changed) head/lib/libc/string/timingsafe_bcmp.c (contents, props changed) head/lib/libc/string/timingsafe_memcmp.c (contents, props changed) Modified: head/include/string.h head/lib/libc/string/Makefile.inc head/lib/libc/string/Symbol.map head/lib/libc/string/bcmp.3 head/lib/libc/string/memcmp.3 Modified: head/include/string.h ============================================================================== --- head/include/string.h Sun Aug 14 22:58:06 2016 (r304105) +++ head/include/string.h Sun Aug 14 23:38:50 2016 (r304106) @@ -134,6 +134,8 @@ typedef __ssize_t ssize_t; void swab(const void * __restrict, void * __restrict, ssize_t); #endif /* _SWAB_DECLARED */ +int timingsafe_bcmp(const void *, const void *, size_t); +int timingsafe_memcmp(const void *, const void *, size_t); #endif /* __BSD_VISIBLE */ #if __POSIX_VISIBLE >= 200809 || defined(_XLOCALE_H_) Modified: head/lib/libc/string/Makefile.inc ============================================================================== --- head/lib/libc/string/Makefile.inc Sun Aug 14 22:58:06 2016 (r304105) +++ head/lib/libc/string/Makefile.inc Sun Aug 14 23:38:50 2016 (r304106) @@ -16,7 +16,10 @@ MISRCS+=bcmp.c bcopy.c bzero.c explicit_ strcspn.c strdup.c strerror.c strlcat.c strlcpy.c strlen.c strmode.c \ strncat.c strncmp.c strncpy.c strndup.c strnlen.c strnstr.c \ strpbrk.c strrchr.c strsep.c strsignal.c strspn.c strstr.c strtok.c \ - strxfrm.c swab.c wcpcpy.c wcpncpy.c wcscasecmp.c wcscat.c \ + strxfrm.c swab.c \ + timingsafe_bcmp.c \ + timingsafe_memcmp.c \ + wcpcpy.c wcpncpy.c wcscasecmp.c wcscat.c \ wcschr.c wcscmp.c wcscoll.c wcscpy.c wcscspn.c wcsdup.c \ wcslcat.c wcslcpy.c wcslen.c wcsncasecmp.c wcsncat.c wcsncmp.c \ wcsncpy.c wcsnlen.c wcspbrk.c \ @@ -34,7 +37,9 @@ MAN+= bcmp.3 bcopy.3 bstring.3 bzero.3 f memcmp.3 memcpy.3 memmem.3 memmove.3 memset.3 strcasecmp.3 strcat.3 \ strchr.3 strcmp.3 strcoll.3 strcpy.3 strdup.3 strerror.3 \ string.3 strlcpy.3 strlen.3 strmode.3 strpbrk.3 strsep.3 \ - strspn.3 strstr.3 strtok.3 strxfrm.3 swab.3 wcscoll.3 wcstok.3 \ + strspn.3 strstr.3 strtok.3 strxfrm.3 swab.3 \ + timingsafe_bcmp.3 \ + wcscoll.3 wcstok.3 \ wcswidth.3 wcsxfrm.3 wmemchr.3 MLINKS+=bzero.3 explicit_bzero.3 @@ -69,6 +74,7 @@ MLINKS+=strstr.3 strcasestr.3 \ strstr.3 strcasestr_l.3 MLINKS+=strtok.3 strtok_r.3 MLINKS+=strxfrm.3 strxfrm_l.3 +MLINKS+=timingsafe_bcmp.3 timingsafe_memcmp.3 MLINKS+=wmemchr.3 wcpcpy.3 \ wmemchr.3 wcpncpy.3 \ wmemchr.3 wcscasecmp.3 \ Modified: head/lib/libc/string/Symbol.map ============================================================================== --- head/lib/libc/string/Symbol.map Sun Aug 14 22:58:06 2016 (r304105) +++ head/lib/libc/string/Symbol.map Sun Aug 14 23:38:50 2016 (r304106) @@ -104,6 +104,11 @@ FBSD_1.4 { explicit_bzero; }; +FBSD_1.5 { + timingsafe_bcmp; + timingsafe_memcmp; +}; + FBSDprivate_1.0 { __strtok_r; }; Modified: head/lib/libc/string/bcmp.3 ============================================================================== --- head/lib/libc/string/bcmp.3 Sun Aug 14 22:58:06 2016 (r304105) +++ head/lib/libc/string/bcmp.3 Sun Aug 14 23:38:50 2016 (r304106) @@ -30,7 +30,7 @@ .\" @(#)bcmp.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd August 15, 2016 .Dt BCMP 3 .Os .Sh NAME @@ -62,7 +62,8 @@ The strings may overlap. .Xr strcasecmp 3 , .Xr strcmp 3 , .Xr strcoll 3 , -.Xr strxfrm 3 +.Xr strxfrm 3 , +.Xr timingsafe_bcmp 3 .Sh HISTORY A .Fn bcmp Modified: head/lib/libc/string/memcmp.3 ============================================================================== --- head/lib/libc/string/memcmp.3 Sun Aug 14 22:58:06 2016 (r304105) +++ head/lib/libc/string/memcmp.3 Sun Aug 14 23:38:50 2016 (r304106) @@ -32,7 +32,7 @@ .\" @(#)memcmp.3 8.1 (Berkeley) 6/4/93 .\" $FreeBSD$ .\" -.Dd June 4, 1993 +.Dd August 15, 2016 .Dt MEMCMP 3 .Os .Sh NAME @@ -75,6 +75,7 @@ Zero-length strings are always identical .Xr strcmp 3 , .Xr strcoll 3 , .Xr strxfrm 3 , +.Xr timingsafe_memcmp 3 , .Xr wmemcmp 3 .Sh STANDARDS The Added: head/lib/libc/string/timingsafe_bcmp.3 ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/string/timingsafe_bcmp.3 Sun Aug 14 23:38:50 2016 (r304106) @@ -0,0 +1,92 @@ +.\" $OpenBSD: timingsafe_bcmp.3,v 1.2 2014/06/21 20:22:15 tedu Exp $ +.\" +.\" Copyright (c) 2014 Google Inc. +.\" +.\" 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. +.\" +.\" $FreeBSD$ +.Dd August 15, 2016 +.Dt TIMINGSAFE_BCMP 3 +.Os +.Sh NAME +.Nm timingsafe_bcmp , +.Nm timingsafe_memcmp +.Nd timing-safe byte sequence comparisons +.Sh SYNOPSIS +.In string.h +.Ft int +.Fn timingsafe_bcmp "const void *b1" "const void *b2" "size_t len" +.Ft int +.Fn timingsafe_memcmp "const void *b1" "const void *b2" "size_t len" +.Sh DESCRIPTION +The +.Fn timingsafe_bcmp +and +.Fn timingsafe_memcmp +functions lexicographically compare the first +.Fa len +bytes (each interpreted as an +.Vt unsigned char ) +pointed to by +.Fa b1 +and +.Fa b2 . +.Pp +Additionally, their running times are independent of the byte sequences compared, +making them safe to use for comparing secret values such as cryptographic MACs. +In contrast, +.Xr bcmp 3 +and +.Xr memcmp 3 +may short-circuit after finding the first differing byte. +.Sh RETURN VALUES +The +.Fn timingsafe_bcmp +function returns 0 or not zero if the byte sequence pointed to by +.Fa b1 +compares equal to or not equal to (respectively) +the byte sequence pointed to by +.Fa b2 . +.Pp +The +.Fn timingsafe_memcmp +function returns a negative value, 0, or positive value if the byte sequence +pointed to by +.Fa b1 +compares less than, equal to, or greater than (respectively) +the byte sequence pointed to by +.Fa b2 . +.Sh SEE ALSO +.Xr bcmp 3 , +.Xr memcmp 3 +.Sh STANDARDS +The +.Fn timingsafe_bcmp +and +.Fn timingsafe_memcmp +functions are +.Fx +extensions. +.Sh HISTORY +The +.Fn timingsafe_bcmp +function first appeared in +.Ox 4.9 . +.Pp +The +.Fn timingsafe_memcmp +function first appeared in +.Ox 5.6 . +.Pp +Both functions first appeared in +.Fx 12.0 . Added: head/lib/libc/string/timingsafe_bcmp.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/string/timingsafe_bcmp.c Sun Aug 14 23:38:50 2016 (r304106) @@ -0,0 +1,36 @@ +/* $OpenBSD: timingsafe_bcmp.c,v 1.3 2015/08/31 02:53:57 guenther Exp $ */ +/* + * Copyright (c) 2010 Damien Miller. All rights reserved. + * + * 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 +__FBSDID("$FreeBSD$"); + +#include + +int __timingsafe_bcmp(const void *, const void *, size_t); + +int +__timingsafe_bcmp(const void *b1, const void *b2, size_t n) +{ + const unsigned char *p1 = b1, *p2 = b2; + int ret = 0; + + for (; n > 0; n--) + ret |= *p1++ ^ *p2++; + return (ret != 0); +} + +__weak_reference(__timingsafe_bcmp, timingsafe_bcmp); Added: head/lib/libc/string/timingsafe_memcmp.c ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/lib/libc/string/timingsafe_memcmp.c Sun Aug 14 23:38:50 2016 (r304106) @@ -0,0 +1,53 @@ +/* $OpenBSD: timingsafe_memcmp.c,v 1.2 2015/08/31 02:53:57 guenther Exp $ */ +/* + * Copyright (c) 2014 Google Inc. + * + * 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 +__FBSDID("$FreeBSD$"); + +#include +#include + +int __timingsafe_memcmp(const void *, const void *, size_t); + +int +__timingsafe_memcmp(const void *b1, const void *b2, size_t len) +{ + const unsigned char *p1 = b1, *p2 = b2; + size_t i; + int res = 0, done = 0; + + for (i = 0; i < len; i++) { + /* lt is -1 if p1[i] < p2[i]; else 0. */ + int lt = (p1[i] - p2[i]) >> CHAR_BIT; + + /* gt is -1 if p1[i] > p2[i]; else 0. */ + int gt = (p2[i] - p1[i]) >> CHAR_BIT; + + /* cmp is 1 if p1[i] > p2[i]; -1 if p1[i] < p2[i]; else 0. */ + int cmp = lt - gt; + + /* set res = cmp if !done. */ + res |= cmp & ~done; + + /* set done if p1[i] != p2[i]. */ + done |= lt | gt; + } + + return (res); +} + +__weak_reference(__timingsafe_memcmp, timingsafe_memcmp);