Commit b713c4ff authored by Rich Salz's avatar Rich Salz
Browse files

Improve some BN documentation. 



Thanks to Nicolas Schodet for pointing this out.

Reviewed-by: default avatarTim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5141)
parent fd2941c8

doc/man3/BN_zero.pod

+14 −9
Original line number Diff line number Diff line
@@ -14,24 +14,26 @@ operations 


 const BIGNUM *BN_value_one(void);



 int BN_set_word(BIGNUM *a, unsigned long w);

 unsigned long BN_get_word(BIGNUM *a);

 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 an unsigned

long.

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>, and 0xffffffffL if B<a> cannot

be represented as an unsigned long.

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.
@@ -39,8 +41,11 @@ BN_zero() never fails and returns no value. 


=head1 BUGS



If a B<BIGNUM> is equal to 0xffffffffL it can be represented as an

unsigned long but this value is also returned on error.

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
@@ -53,7 +58,7 @@ versions returned an int. 


=head1 COPYRIGHT



Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.

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