Commit 8b2124ab authored by Rich Salz's avatar Rich Salz
Browse files

Fix BN doc 

Backport from https://github.com/openssl/openssl/pull/5141



Reviewed-by: default avatarViktor Dukhovni <viktor@openssl.org>
Reviewed-by: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/5151)
parent 77882a94

doc/crypto/BN_zero.pod

+12 −9
Original line number Diff line number Diff line
@@ -14,8 +14,8 @@ 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);

 BN_ULONG BN_get_word(BIGNUM *a);



Deprecated:
@@ -25,19 +25,21 @@ Deprecated: 


=head1 DESCRIPTION



B<BN_ULONG> is a macro that will be an unsigned integral type optimied

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 B<BN_ULONG>.



BN_one(), BN_set_word() and the deprecated version of BN_zero()

return 1 on success, 0 otherwise.
@@ -46,10 +48,11 @@ The preferred version of BN_zero() never fails and returns no value. 


=head1 BUGS



Someone might change the constant.

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.



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

unsigned long but this value is also returned on error.

B<BN_ULONG> should probably be a typedef.



=head1 SEE ALSO