BN_zero.pod revision 68651 
1214571Sdim=pod
2214571Sdim
3214571Sdim=head1 NAME
4214571Sdim
5214571SdimBN_zero, BN_one, BN_value_one, BN_set_word, BN_get_word - BIGNUM assignment
6214571Sdimoperations
7214571Sdim
8214571Sdim=head1 SYNOPSIS
9214571Sdim
10214571Sdim #include <openssl/bn.h>
11214571Sdim
12214571Sdim int BN_zero(BIGNUM *a);
13214571Sdim int BN_one(BIGNUM *a);
14214571Sdim
15214571Sdim BIGNUM *BN_value_one(void);
16214571Sdim
17214571Sdim int BN_set_word(BIGNUM *a, unsigned long w);
18214571Sdim unsigned long BN_get_word(BIGNUM *a);
19214571Sdim
20214571Sdim=head1 DESCRIPTION
21214571Sdim
22214571SdimBN_zero(), BN_one() and BN_set_word() set B<a> to the values 0, 1 and
23214571SdimB<w> respectively.  BN_zero() and BN_one() are macros.
24214571Sdim
25214571SdimBN_value_one() returns a B<BIGNUM> constant of value 1. This constant
26214571Sdimis useful for use in comparisons and assignment.
27214571Sdim
28214571SdimBN_get_word() returns B<a>, if it can be represented as an unsigned
29214571Sdimlong.
30214571Sdim
31214571Sdim=head1 RETURN VALUES
32214571Sdim
33214571SdimBN_get_word() returns the value B<a>, and 0xffffffffL if B<a> cannot
34214571Sdimbe represented as an unsigned long.
35214571Sdim
36214571SdimBN_zero(), BN_one() and BN_set_word() return 1 on success, 0 otherwise.
37214571SdimBN_value_one() returns the constant.
38214571Sdim
39=head1 BUGS
40
41Someone might change the constant.
42
43If a B<BIGNUM> is equal to 0xffffffffL it can be represented as an
44unsigned long but this value is also returned on error.
45
46=head1 SEE ALSO
47
48L<bn(3)|bn(3)>, L<BN_bn2bin(3)|BN_bn2bin(3)>
49
50=head1 HISTORY
51
52BN_zero(), BN_one() and BN_set_word() are available in all versions of
53SSLeay and OpenSSL. BN_value_one() and BN_get_word() were added in
54SSLeay 0.8.
55
56=cut
57