openssl/doc/man3/BN_zero.pod
Rich Salz b713c4fff7 Improve some BN documentation.
Thanks to Nicolas Schodet for pointing this out.

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5141)
2018-01-23 09:38:42 -05:00

68 lines
1.7 KiB
Text

=pod
=head1 NAME
BN_zero, BN_one, BN_value_one, BN_set_word, BN_get_word - BIGNUM assignment
operations
=head1 SYNOPSIS
#include <openssl/bn.h>
void BN_zero(BIGNUM *a);
int BN_one(BIGNUM *a);
const BIGNUM *BN_value_one(void);
int BN_set_word(BIGNUM *a, BN_ULONG w);
unsigned BN_ULONG BN_get_word(BIGNUM *a);
=head1 DESCRIPTION
B<BN_ULONG> is a macro that will be an unsigned integral type optimized
for the most efficient implementation on the local platform.
BN_zero(), BN_one() and BN_set_word() set B<a> to the values 0, 1 and
B<w> respectively. BN_zero() and BN_one() are macros.
BN_value_one() returns a B<BIGNUM> constant of value 1. This constant
is useful for use in comparisons and assignment.
BN_get_word() returns B<a>, if it can be represented as a B<BN_ULONG>.
=head1 RETURN VALUES
BN_get_word() returns the value B<a>, or all-bits-set if B<a> cannot
be represented as a single integer.
BN_one() and BN_set_word() return 1 on success, 0 otherwise.
BN_value_one() returns the constant.
BN_zero() never fails and returns no value.
=head1 BUGS
If a B<BIGNUM> is equal to the value of all-bits-set, it will collide
with the error condition returned by BN_get_word() which uses that
as an error value.
B<BN_ULONG> should probably be a typedef.
=head1 SEE ALSO
L<BN_bn2bin(3)>
=head1 HISTORY
In OpenSSL 0.9.8, BN_zero() was changed to not return a value; previous
versions returned an int.
=head1 COPYRIGHT
Copyright 2000-2018 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