Add #defines for magic numbers in API.

[openssl.git] / doc / crypto / BN_rand.pod

diff --git a/doc/crypto/BN_rand.pod b/doc/crypto/BN_rand.pod
index f090df6908ff5be857dbdeb97f4c1ead5760bb53..ba505e1e647d0523e8e0cd4df35cbefa5a5d02fe 100644 (file)
--- a/doc/crypto/BN_rand.pod
+++ b/doc/crypto/BN_rand.pod
@@ -2,7 +2,7 @@
 
 =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
 
@@ -10,36 +10,57 @@ BN_rand, BN_pseudo_rand - Generate pseudo-random number
 
  int BN_rand(BIGNUM *rnd, int bits, int top, int bottom);
 
- int BN_pseudo_rand(BIGNUM *rnd, int bits, int top,int bottom);
+ int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom);
+
+ int BN_rand_range(BIGNUM *rnd, BIGNUM *range);
+
+ int BN_pseudo_rand_range(BIGNUM *rnd, BIGNUM *range);
 
 =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 true, 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.
+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 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
 non-cryptographic purposes and for certain purposes in cryptographic
 protocols, but usually not for key generation etc.
 
-The PRNG must be seeded prior to calling BN_rand().
+BN_rand_range() generates a cryptographically strong pseudo-random
+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.
+
+The PRNG must be seeded prior to calling BN_rand() or BN_rand_range().
 
 =head1 RETURN VALUES
 
-BN_rand() and BN_pseudo_rand() return 1 on success, 0 on error.
-The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>.
+The functions return 1 on success, 0 on error.
+The error codes can be obtained by L<ERR_get_error(3)>.
 
 =head1 SEE ALSO
 
-L<bn(3)|bn(3)>, L<err(3)|err(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 COPYRIGHT
 
-=head1 HISTORY
+Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
 
-BN_rand() is available in all versions of SSLeay and OpenSSL.
-BN_pseudo_rand() was added in OpenSSL 0.9.5.
+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