|  | =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, unsigned long w); | 
|  | unsigned long BN_get_word(BIGNUM *a); | 
|  |  | 
|  | Deprecated: | 
|  |  | 
|  | #if OPENSSL_API_COMPAT < 0x00908000L | 
|  | int BN_zero(BIGNUM *a); | 
|  | #endif | 
|  |  | 
|  | =head1 DESCRIPTION | 
|  |  | 
|  | 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 an unsigned | 
|  | long. | 
|  |  | 
|  | =head1 RETURN VALUES | 
|  |  | 
|  | BN_get_word() returns the value B<a>, and 0xffffffffL if B<a> cannot | 
|  | be represented as an unsigned long. | 
|  |  | 
|  | BN_one(), BN_set_word() and the deprecated version of BN_zero() | 
|  | return 1 on success, 0 otherwise. | 
|  | BN_value_one() returns the constant. | 
|  | The preferred version of BN_zer() never fails and returns no value. | 
|  |  | 
|  | =head1 BUGS | 
|  |  | 
|  | Someone might change the constant. | 
|  |  | 
|  | If a B<BIGNUM> is equal to 0xffffffffL it can be represented as an | 
|  | unsigned long but this value is also returned on error. | 
|  |  | 
|  | =head1 SEE ALSO | 
|  |  | 
|  | L<bn(3)>, L<BN_bn2bin(3)> | 
|  |  | 
|  | =cut |