Constify X509|X509_CRL|X509_REVOKED_get_ext

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

diff --git a/doc/crypto/BN_rand.pod b/doc/crypto/BN_rand.pod
index f0f3b4571ee83ca9cc6ef0d11a5007b96d6126f9..c612c50a8109c127a0238c9010f1469f6505e164 100644 (file)
--- a/doc/crypto/BN_rand.pod
+++ b/doc/crypto/BN_rand.pod
@@ -2,7 +2,7 @@
 
 =head1 NAME
 
-BN_rand - Generate pseudo-random number
+BN_rand, BN_pseudo_rand, BN_rand_range, BN_pseudo_rand_range - generate pseudo-random number
 
 =head1 SYNOPSIS
 
@@ -10,27 +10,52 @@ BN_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_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.
-
-The PRNG must be seeded prior to calling BN_rand().
+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
+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.
+
+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.
+
+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() returns 1 on success, 0 on error.
-The error codes can be obtained by 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
 
-bn(3), err(3), rand(3), RAND_add(), RAND_bytes()
+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.
+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