Add X9.42 KDF.

[openssl.git] / doc / man3 / RAND_bytes.pod

diff --git a/doc/man3/RAND_bytes.pod b/doc/man3/RAND_bytes.pod
index 284b9dbe4da60240ed98fb9643fba78fc4dcea42..fb1e1c9a223bb7511568f351dfa19f32dd22ce20 100644 (file)
--- a/doc/man3/RAND_bytes.pod
+++ b/doc/man3/RAND_bytes.pod
@@ -11,22 +11,30 @@ RAND_bytes, RAND_priv_bytes, RAND_pseudo_bytes - generate random data
  int RAND_bytes(unsigned char *buf, int num);
  int RAND_priv_bytes(unsigned char *buf, int num);
 
-Deprecated:
+Deprecated since OpenSSL 1.1.0, can be hidden entirely by defining
+B<OPENSSL_API_COMPAT> with a suitable version value, see
+L<openssl_user_macros(7)>:
 
- #if OPENSSL_API_COMPAT < 0x10100000L
  int RAND_pseudo_bytes(unsigned char *buf, int num);
- #endif
 
 =head1 DESCRIPTION
 
 RAND_bytes() puts B<num> cryptographically strong pseudo-random bytes
-into B<buf>. An error occurs if the CSPRNG has not been seeded with
-enough randomness to ensure an unpredictable byte sequence.
+into B<buf>.
 
 RAND_priv_bytes() has the same semantics as RAND_bytes().  It is intended to
-be used for generating long-term private keys. If using the default
-RAND_METHOD, this function uses a separate instance of the PRNG so that
-a compromise of the global generator will not affect such key generation.
+be used for generating values that should remain private. If using the
+default RAND_METHOD, this function uses a separate "private" PRNG
+instance so that a compromise of the "public" PRNG instance will not
+affect the secrecy of these private values, as described in L<RAND(7)>
+and L<RAND_DRBG(7)>.
+
+=head1 NOTES
+
+Always check the error return value of RAND_bytes() and
+RAND_priv_bytes() and do not take randomness for granted: an error occurs
+if the CSPRNG has not been seeded with enough randomness to ensure an
+unpredictable byte sequence.
 
 =head1 RETURN VALUES
 
@@ -35,22 +43,34 @@ return 1 on success, -1 if not supported by the current
 RAND method, or 0 on other failure. The error code can be
 obtained by L<ERR_get_error(3)>.
 
-=head1 HISTORY
-
-RAND_pseudo_bytes() was deprecated in OpenSSL 1.1.0; use RAND_bytes() instead.
-
 =head1 SEE ALSO
 
 L<RAND_add(3)>,
 L<RAND_bytes(3)>,
+L<RAND_priv_bytes(3)>,
 L<ERR_get_error(3)>,
-L<RAND(7)>
+L<RAND(7)>,
+L<RAND_DRBG(7)>
+
+=head1 HISTORY
+
+=over 2
+
+=item *
+
+RAND_pseudo_bytes() was deprecated in OpenSSL 1.1.0; use RAND_bytes() instead.
+
+=item *
+
+The RAND_priv_bytes() function was added in OpenSSL 1.1.1.
+
+=back
 
 =head1 COPYRIGHT
 
-Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
 
-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (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>.