=pod

=head1 NAME

BN_add_word, BN_sub_word, BN_mul_word, BN_div_word, BN_mod_word - arithmetic
functions on BIGNUMs with integers

=head1 SYNOPSIS

 #include <openssl/bn.h>

 int BN_add_word(BIGNUM *a, BN_ULONG w);

 int BN_sub_word(BIGNUM *a, BN_ULONG w);

 int BN_mul_word(BIGNUM *a, BN_ULONG w);

 BN_ULONG BN_div_word(BIGNUM *a, BN_ULONG w);

 BN_ULONG BN_mod_word(const BIGNUM *a, BN_ULONG w);

=head1 DESCRIPTION

These functions perform arithmetic operations on BIGNUMs with unsigned
integers. They are much more efficient than the normal BIGNUM
arithmetic operations.

BN_add_word() adds B<w> to B<a> (C<a+=w>).

BN_sub_word() subtracts B<w> from B<a> (C<a-=w>).

BN_mul_word() multiplies B<a> and B<w> (C<a*=w>).

BN_div_word() divides B<a> by B<w> (C<a/=w>) and returns the remainder.

BN_mod_word() returns the remainder of B<a> divided by B<w> (C<a%w>).

For BN_div_word() and BN_mod_word(), B<w> must not be 0.

=head1 RETURN VALUES

BN_add_word(), BN_sub_word() and BN_mul_word() return 1 for success, 0
on error. The error codes can be obtained by L<ERR_get_error(3)>.

BN_mod_word() and BN_div_word() return B<a>%B<w> on success and
B<(BN_ULONG)-1> if an error occurred.

=head1 SEE ALSO

L<ERR_get_error(3)>, L<BN_add(3)>

=head1 COPYRIGHT

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
L<https://www.openssl.org/source/license.html>.

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