From 4512d7be41e86f5aa329641c14e0cc1b9508dbcb Mon Sep 17 00:00:00 2001 From: schwarze <> Date: Sun, 20 Nov 2016 16:51:02 +0000 Subject: Add Copyright and license. Merge documentation of BN_with_flags(3) from OpenSSL. --- src/lib/libcrypto/man/BN_copy.3 | 114 ++++++++++++++++++++++++++++++++++++++-- 1 file changed, 109 insertions(+), 5 deletions(-) (limited to 'src') diff --git a/src/lib/libcrypto/man/BN_copy.3 b/src/lib/libcrypto/man/BN_copy.3 index 80b3087c62..f6110863a0 100644 --- a/src/lib/libcrypto/man/BN_copy.3 +++ b/src/lib/libcrypto/man/BN_copy.3 @@ -1,11 +1,61 @@ -.\" $OpenBSD: BN_copy.3,v 1.2 2016/11/06 15:52:50 jmc Exp $ +.\" $OpenBSD: BN_copy.3,v 1.3 2016/11/20 16:51:02 schwarze Exp $ +.\" OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 .\" -.Dd $Mdocdate: November 6 2016 $ +.\" This file was written by Ulf Moeller +.\" and Matt Caswell . +.\" Copyright (c) 2000, 2015 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: November 20 2016 $ .Dt BN_COPY 3 .Os .Sh NAME .Nm BN_copy , -.Nm BN_dup +.Nm BN_dup , +.Nm BN_with_flags .Nd copy BIGNUMs .Sh SYNOPSIS .In openssl/bn.h @@ -18,6 +68,12 @@ .Fo BN_dup .Fa "const BIGNUM *from" .Fc +.Ft void +.Fo BN_with_flags +.Fa "BIGNUM *dest" +.Fa "const BIGNUM *b" +.Fa "int flags" +.Fc .Sh DESCRIPTION .Fn BN_copy copies @@ -29,16 +85,64 @@ creates a new .Vt BIGNUM containing the value .Fa from . +.Pp +.Fn BN_with_flags +creates a +.Em temporary +shallow copy of +.Fa b +in +.Fa dest . +It places significant restrictions on the copied data. +Applications that do not adhere to these restrictions +may encounter unexpected side effects or crashes. +For that reason, use of this function is discouraged. +.Pp +Any flags provided in +.Fa flags +will be set in +.Fa dest +in addition to any flags already set in +.Fa b . +For example, this can be used to create a temporary copy of a +.Vt BIGNUM +with the +.Dv BN_FLG_CONSTTIME +flag set for constant time operations. +.Pp +The temporary copy in +.Fa dest +will share some internal state with +.Fa b . +For this reason, the following restrictions apply to the use of +.Fa dest : +.Bl -bullet +.It +.Fa dest +should be a newly allocated +.Vt BIGNUM +obtained via a call to +.Xr BN_new 3 . +It should not have been used for other purposes or initialised in any way. +.It +.Fa dest +must only be used in "read-only" operations, i.e. typically those +functions where the relevant parameter is declared "const". +.It +.Fa dest +must be used and freed before any further subsequent use of +.Fa b . +.El .Sh RETURN VALUES .Fn BN_copy returns .Fa to -on success, +on success or .Dv NULL on error. .Fn BN_dup returns the new -.Vt BIGNUM , +.Vt BIGNUM or .Dv NULL on error. -- cgit v1.2.3-55-g6feb