import the CRYPTO_memcmp(3) manual from OpenSSL 1.1.1,

still under a free license, tweaked by me

2 files changed, 97 insertions, 1 deletions

diff --git a/lib/libcrypto/man/CRYPTO_memcmp.3 b/lib/libcrypto/man/CRYPTO_memcmp.3
new file mode 100644
index 00000000000..cbc0030c55d
--- /dev/null
+++ b/lib/libcrypto/man/CRYPTO_memcmp.3
@@ -0,0 +1,95 @@
+.\" $OpenBSD: CRYPTO_memcmp.3,v 1.1 2019/08/25 06:20:22 schwarze Exp $
+.\" full merge up to: OpenSSL 1075139c Jun 24 09:18:48 2019 +1000
+.\"
+.\" This file was written by Pauli <paul.dale@oracle.com>.
+.\" Copyright (c) 2019 The OpenSSL Project.  All rights reserved.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\"
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\"
+.\" 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 must display the following acknowledgment:
+.\"    "This product includes software developed by the OpenSSL Project
+.\"    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+.\"
+.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+.\"    endorse or promote products derived from this software without
+.\"    prior written permission. For written permission, please contact
+.\"    openssl-core@openssl.org.
+.\"
+.\" 5. Products derived from this software may not be called "OpenSSL"
+.\"    nor may "OpenSSL" appear in their names without prior written
+.\"    permission of the OpenSSL Project.
+.\"
+.\" 6. Redistributions of any form whatsoever must retain the following
+.\"    acknowledgment:
+.\"    "This product includes software developed by the OpenSSL Project
+.\"    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+.\" OF THE POSSIBILITY OF SUCH DAMAGE.
+.\"
+.Dd $Mdocdate: August 25 2019 $
+.Dt CRYPTO_MEMCMP 3
+.Os
+.Sh NAME
+.Nm CRYPTO_memcmp
+.Nd constant time memory comparison
+.Sh SYNOPSIS
+.In openssl/crypto.h
+.Ft int
+.Fo CRYPTO_memcmp
+.Fa "const void *a"
+.Fa "const void *b"
+.Fa "size_t len"
+.Fc
+.Sh DESCRIPTION
+.Fn CRYPTO_memcmp
+compares the
+.Fa len
+bytes pointed to by
+.Fa a
+and
+.Fa b
+for equality.
+It takes an amount of time dependent on
+.Fa len ,
+but independent of the contents of the memory regions pointed to by
+.Fa a
+and
+.Fa b .
+.Sh RETURN VALUES
+.Fn CRYPTO_memcmp
+returns 0 if the content of the memory regions is equal
+or non-zero otherwise.
+.Sh HISTORY
+.Fn CRYPTO_memcmp
+first appeared in OpenSSL 1.0.1d and has been available since
+.Ox 5.6 .
+.Sh BUGS
+Unlike
+.Xr memcmp 3
+and
+.Xr timingsafe_memcmp 3 ,
+this function cannot be used to order the two memory regions.
+In the current implementation, the return value is always greater
+than or equal to 0.
diff --git a/lib/libcrypto/man/Makefile b/lib/libcrypto/man/Makefile
index 60bd8b53cc8..219450e234b 100644
--- a/lib/libcrypto/man/Makefile
+++ b/lib/libcrypto/man/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.154 2019/08/23 12:23:39 schwarze Exp $
+# $OpenBSD: Makefile,v 1.155 2019/08/25 06:20:22 schwarze Exp $
 
 .include <bsd.own.mk>
 
@@ -69,6 +69,7 @@ MAN=	\
 	CONF_modules_load_file.3 \
 	CRYPTO_get_mem_functions.3 \
 	CRYPTO_lock.3 \
+	CRYPTO_memcmp.3 \
 	CRYPTO_set_ex_data.3 \
 	DES_set_key.3 \
 	DH_generate_key.3 \