Commit f67cbb74 authored by Rich Salz's avatar Rich Salz
Browse files

Add #defines for magic numbers in API. 



Binary- and backward-compatible.  Just better.

Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1429)
parent 5898b8eb

doc/crypto/BN_rand.pod

+11 −6
Original line number Diff line number Diff line
@@ -19,13 +19,18 @@ BN_rand, BN_pseudo_rand, BN_rand_range, BN_pseudo_rand_range - generate pseudo-r 
=head1 DESCRIPTION



BN_rand() generates a cryptographically strong pseudo-random number of

B<bits> in length and stores it in B<rnd>. If B<top> is -1, the

most significant bit of the random number can be zero. If B<top> is 0,

it is set to 1, and if B<top> is 1, the two most significant bits of

B<bits> in length and stores it in B<rnd>.

The value of B<bits> must be zero or greater.

The B<top> parameters specifies

requirements on the most significant bit of the generated number.

If it is B<BN_RAND_TOP_ANY>, there is no constraint.

If it is B<BN_RAND_TOP_ONE>, the top bit must be one.

If it is B<BN_RAND_TOP_TWO>, the two most significant bits of

the number will be set to 1, so that the product of two such random

numbers will always have 2*B<bits> length.  If B<bottom> is true, the

number will be odd. The value of B<bits> must be zero or greater. If B<bits> is

1 then B<top> cannot also be 1.

numbers will always have 2*B<bits> length.

If B<bottom> is B<BN_RAND_BOTTOM_ODD>, the number will be odd; if it

is B<BN_RAND_BOTTOM_ANY> it can be odd or even.

If B<bits> is 1 then B<top> cannot also be B<BN_RAND_FLG_TOPTWO>.



BN_pseudo_rand() does the same, but pseudo-random numbers generated by

this function are not necessarily unpredictable. They can be used for

include/openssl/bn.h

+9 −0
Original line number Diff line number Diff line
@@ -82,6 +82,15 @@ extern "C" { 
void BN_set_flags(BIGNUM *b, int n);

int BN_get_flags(const BIGNUM *b, int n);



/* Values for |top| in BN_rand() */

#define BN_RAND_TOP_ANY    -1

#define BN_RAND_TOP_ONE     0

#define BN_RAND_TOP_TWO     1



/* Values for |bottom| in BN_rand() */

#define BN_RAND_BOTTOM_ANY  0

#define BN_RAND_BOTTOM_ODD  1



/*

 * get a clone of a BIGNUM with changed flags, for *temporary* use only (the

 * two BIGNUMs cannot be used in parallel!). Also only for *read only* use. The