1 files changed, 30 insertions, 14 deletions
diff --git a/src/lib/libc/string/bcmp.3 b/src/lib/libc/string/bcmp.3
index 118c55c579..1660b4356b 100644
--- a/src/lib/libc/string/bcmp.3
+++ b/src/lib/libc/string/bcmp.3
@@ -11,11 +11,7 @@
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
-.\" 3. All advertising materials mentioning features or use of this software
+.\" 3. Neither the name of the University nor the names of its contributors
-.\"    must display the following acknowledgement:
-.\"     This product includes software developed by the University of
-.\"     California, Berkeley and its contributors.
-.\" 4. Neither the name of the University nor the names of its contributors
 .\"    may be used to endorse or promote products derived from this software
 .\"    without specific prior written permission.
 .\"
@@ -31,24 +27,25 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.\"     from: @(#)bcmp.3        5.4 (Berkeley) 4/19/91
+.\"     $OpenBSD: bcmp.3,v 1.9 2011/07/25 00:38:52 schwarze Exp $
-.\"     $Id: bcmp.3,v 1.1.1.1 1995/10/18 08:42:20 deraadt Exp $
 .\"
-.Dd April 19, 1991
+.Dd $Mdocdate: July 25 2011 $
 .Dt BCMP 3
-.Os BSD 4.2
+.Os
 .Sh NAME
-.Nm bcmp
+.Nm bcmp ,
+.Nm timingsafe_bcmp
 .Nd compare byte string
 .Sh SYNOPSIS
 .Fd #include <string.h>
 .Ft int
 .Fn bcmp "const void *b1" "const void *b2" "size_t len"
+.Ft int
+.Fn timingsafe_bcmp "const void *b1" "const void *b2" "size_t len"
 .Sh DESCRIPTION
 The
 .Fn bcmp
-function
+function compares byte string
-compares byte string
 .Fa b1
 against byte string
 .Fa b2 ,
@@ -59,6 +56,20 @@ bytes long.
 Zero-length strings are always identical.
 .Pp
 The strings may overlap.
+.Pp
+The
+.Fn timingsafe_bcmp
+function has the same semantics as
+.Fn bcmp ,
+but its running time is independent of the contents of
+.Fa b1
+and
+.Fa b2 ,
+making it safe to use for comparing secret values such as cryptographic MACs.
+In contrast,
+.Fn bcmp
+returns after finding the first differing byte,
+making it vulnerable to timing attacks.
 .Sh SEE ALSO
 .Xr memcmp 3 ,
 .Xr strcasecmp 3 ,
@@ -66,7 +77,12 @@ The strings may overlap.
 .Xr strcoll 3 ,
 .Xr strxfrm 3
 .Sh HISTORY
-A
+The
 .Fn bcmp
-function first appeared in 
+function first appeared in
 .Bx 4.2 .
+.Pp
+The
+.Fn timingsafe_bcmp
+function first appeared in
+.Ox 4.9 .

diff --git a/src/lib/libc/string/bcmp.3 b/src/lib/libc/string/bcmp.3 index 118c55c579..1660b4356b 100644 --- a/src/lib/libc/string/bcmp.3 +++ b/src/lib/libc/string/bcmp.3
@@ -11,11 +11,7 @@
11	.\" 2. Redistributions in binary form must reproduce the above copyright	11	.\" 2. Redistributions in binary form must reproduce the above copyright
12	.\" notice, this list of conditions and the following disclaimer in the	12	.\" notice, this list of conditions and the following disclaimer in the
13	.\" documentation and/or other materials provided with the distribution.	13	.\" documentation and/or other materials provided with the distribution.
14	.\" 3. All advertising materials mentioning features or use of this software	14	.\" 3. Neither the name of the University nor the names of its contributors
15	.\" must display the following acknowledgement:
16	.\" This product includes software developed by the University of
17	.\" California, Berkeley and its contributors.
18	.\" 4. Neither the name of the University nor the names of its contributors
19	.\" may be used to endorse or promote products derived from this software	15	.\" may be used to endorse or promote products derived from this software
20	.\" without specific prior written permission.	16	.\" without specific prior written permission.
21	.\"	17	.\"
@@ -31,24 +27,25 @@
31	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF	27	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32	.\" SUCH DAMAGE.	28	.\" SUCH DAMAGE.
33	.\"	29	.\"
34	.\" from: @(#)bcmp.3 5.4 (Berkeley) 4/19/91	30	.\" $OpenBSD: bcmp.3,v 1.9 2011/07/25 00:38:52 schwarze Exp $
35	.\" $Id: bcmp.3,v 1.1.1.1 1995/10/18 08:42:20 deraadt Exp $
36	.\"	31	.\"
37	.Dd April 19, 1991	32	.Dd $Mdocdate: July 25 2011 $
38	.Dt BCMP 3	33	.Dt BCMP 3
39	.Os BSD 4.2	34	.Os
40	.Sh NAME	35	.Sh NAME
41	.Nm bcmp	36	.Nm bcmp ,
		37	.Nm timingsafe_bcmp
42	.Nd compare byte string	38	.Nd compare byte string
43	.Sh SYNOPSIS	39	.Sh SYNOPSIS
44	.Fd #include <string.h>	40	.Fd #include <string.h>
45	.Ft int	41	.Ft int
46	.Fn bcmp "const void b1" "const void b2" "size_t len"	42	.Fn bcmp "const void b1" "const void b2" "size_t len"
		43	.Ft int
		44	.Fn timingsafe_bcmp "const void b1" "const void b2" "size_t len"
47	.Sh DESCRIPTION	45	.Sh DESCRIPTION
48	The	46	The
49	.Fn bcmp	47	.Fn bcmp
50	function	48	function compares byte string
51	compares byte string
52	.Fa b1	49	.Fa b1
53	against byte string	50	against byte string
54	.Fa b2 ,	51	.Fa b2 ,
@@ -59,6 +56,20 @@ bytes long.
59	Zero-length strings are always identical.	56	Zero-length strings are always identical.
60	.Pp	57	.Pp
61	The strings may overlap.	58	The strings may overlap.
		59	.Pp
		60	The
		61	.Fn timingsafe_bcmp
		62	function has the same semantics as
		63	.Fn bcmp ,
		64	but its running time is independent of the contents of
		65	.Fa b1
		66	and
		67	.Fa b2 ,
		68	making it safe to use for comparing secret values such as cryptographic MACs.
		69	In contrast,
		70	.Fn bcmp
		71	returns after finding the first differing byte,
		72	making it vulnerable to timing attacks.
62	.Sh SEE ALSO	73	.Sh SEE ALSO
63	.Xr memcmp 3 ,	74	.Xr memcmp 3 ,
64	.Xr strcasecmp 3 ,	75	.Xr strcasecmp 3 ,
@@ -66,7 +77,12 @@ The strings may overlap.
66	.Xr strcoll 3 ,	77	.Xr strcoll 3 ,
67	.Xr strxfrm 3	78	.Xr strxfrm 3
68	.Sh HISTORY	79	.Sh HISTORY
69	A	80	The
70	.Fn bcmp	81	.Fn bcmp
71	function first appeared in	82	function first appeared in
72	.Bx 4.2 .	83	.Bx 4.2 .
		84	.Pp
		85	The
		86	.Fn timingsafe_bcmp
		87	function first appeared in
		88	.Ox 4.9 .