70 lines
2.0 KiB
Plaintext
70 lines
2.0 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BN_copy, BN_dup, BN_with_flags - copy BIGNUMs
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/bn.h>
|
|
|
|
BIGNUM *BN_copy(BIGNUM *to, const BIGNUM *from);
|
|
|
|
BIGNUM *BN_dup(const BIGNUM *from);
|
|
|
|
void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
BN_copy() copies B<from> to B<to>. BN_dup() creates a new B<BIGNUM>
|
|
containing the value B<from>.
|
|
|
|
BN_with_flags creates a B<temporary> shallow copy of B<b> in B<dest>. It places
|
|
significant restrictions on the copied data. Applications that do no adhere to
|
|
these restrictions may encounter unexpected side effects or crashes. For that
|
|
reason use of this function is discouraged. Any flags provided in B<flags> will
|
|
be set in B<dest> in addition to any flags already set in B<b>. For example this
|
|
might commonly be used to create a temporary copy of a BIGNUM with the
|
|
B<BN_FLG_CONSTTIME> flag set for constant time operations. The temporary copy in
|
|
B<dest> will share some internal state with B<b>. For this reason the following
|
|
restrictions apply to the use of B<dest>:
|
|
|
|
=over 2
|
|
|
|
=item *
|
|
|
|
B<dest> should be a newly allocated BIGNUM obtained via a call to BN_new(). It
|
|
should not have been used for other purposes or initialised in any way.
|
|
|
|
=item *
|
|
|
|
B<dest> must only be used in "read-only" operations, i.e. typically those
|
|
functions where the relevant parameter is declared "const".
|
|
|
|
=item *
|
|
|
|
B<dest> must be used and freed before any further subsequent use of B<b>
|
|
|
|
=back
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
BN_copy() returns B<to> on success, NULL on error. BN_dup() returns
|
|
the new B<BIGNUM>, and NULL on error. The error codes can be obtained
|
|
by L<ERR_get_error(3)>.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ERR_get_error(3)>
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the OpenSSL license (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|