| =pod |
| |
| =head1 NAME |
| |
| RAND_bytes, RAND_priv_bytes, RAND_pseudo_bytes - generate random data |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/rand.h> |
| |
| int RAND_bytes(unsigned char *buf, int num); |
| int RAND_priv_bytes(unsigned char *buf, int num); |
| |
| 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)>: |
| |
| int RAND_pseudo_bytes(unsigned char *buf, int num); |
| |
| =head1 DESCRIPTION |
| |
| RAND_bytes() puts B<num> cryptographically strong pseudo-random bytes |
| into B<buf>. |
| |
| RAND_priv_bytes() has the same semantics as RAND_bytes(). It is intended to |
| 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 |
| |
| RAND_bytes() and RAND_priv_bytes() |
| 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 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_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 2000-2019 The OpenSSL Project Authors. All Rights Reserved. |
| |
| 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>. |
| |
| =cut |
