=head1 NAME
-BN_rand, BN_pseudo_rand - generate pseudo-random number
+BN_rand, BN_pseudo_rand, BN_rand_range, BN_pseudo_rand_range - generate pseudo-random number
=head1 SYNOPSIS
=head1 DESCRIPTION
BN_rand() generates a cryptographically strong pseudo-random number of
-B<bits> 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>.
+If B<bits> is less than zero, or too small to
+accomodate the requirements specified by the B<top> and B<bottom>
+parameters, an error is returned.
+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.
+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
protocols, but usually not for key generation etc.
BN_rand_range() generates a cryptographically strong pseudo-random
-number B<rnd> in the range 0 <lt>= B<rnd> E<lt> B<range>.
+number B<rnd> in the range 0 E<lt>= B<rnd> E<lt> B<range>.
BN_pseudo_rand_range() does the same, but is based on BN_pseudo_rand(),
and hence numbers generated by it are not necessarily unpredictable.
=head1 RETURN VALUES
The functions return 1 on success, 0 on error.
-The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
+The error codes can be obtained by L<ERR_get_error(3)>.
=head1 SEE ALSO
-L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<rand(3)|rand(3)>,
-L<RAND_add(3)|RAND_add(3)>, L<RAND_bytes(3)|RAND_bytes(3)>
+L<bn(3)>, L<ERR_get_error(3)>, L<rand(3)>,
+L<RAND_add(3)>, L<RAND_bytes(3)>
-=head1 HISTORY
+=head1 COPYRIGHT
-BN_rand() is available in all versions of SSLeay and OpenSSL.
-BN_pseudo_rand() was added in OpenSSL 0.9.5. The B<top> == -1 case
-and the function BN_rand_range() were added in OpenSSL 0.9.6a.
-BN_pseudo_rand_range() was added in OpenSSL 0.9.6c.
+Copyright 2000-2016 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
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
=cut