BN_copy, BN_dup, BN_with_flags - copy BIGNUMs
#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);
BN_copy() copies
from to
to.
BN_dup() creates a new
BIGNUM containing the value
from.
BN_with_flags creates a
temporary shallow copy of
b in
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
flags will be set in
dest in addition to
any flags already set in
b. For example this might commonly be used to
create a temporary copy of a BIGNUM with the
BN_FLG_CONSTTIME flag set
for constant time operations. The temporary copy in
dest will share
some internal state with
b. For this reason the following restrictions
apply to the use of
dest:
- •
-
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.
- •
-
dest must only be used in "read-only"
operations, i.e. typically those functions where the relevant parameter is
declared "const".
- •
-
dest must be used and freed before any further
subsequent use of b
BN_copy() returns
to on success, NULL on error.
BN_dup()
returns the new
BIGNUM, and NULL on error. The error codes can be
obtained by
ERR_get_error(3).
ERR_get_error(3)
Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (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
<
https://www.openssl.org/source/license.html>.