NAME

       BN_zero, BN_one, BN_value_one, BN_set_word, BN_get_word - BIGNUM assignment operations

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);

DESCRIPTION

       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 a to the values 0, 1 and w respectively.
       BN_zero() and BN_one() are macros.

       BN_value_one() returns a BIGNUM constant of value 1. This constant is useful for use in
       comparisons and assignment.

       BN_get_word() returns a, if it can be represented as a BN_ULONG.

RETURN VALUES

       BN_get_word() returns the value a, or all-bits-set if 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.

BUGS

       If a 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.

       BN_ULONG should probably be a typedef.

SEE ALSO

       BN_bn2bin(3)

HISTORY

       In OpenSSL 0.9.8, BN_zero() was changed to not return a value; previous versions returned
       an int.

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