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+=pod
+
+=head1 NAME
+
+RAND_add, RAND_poll, RAND_seed, RAND_status, RAND_event, RAND_screen,
+RAND_keep_random_devices_open
+- add randomness to the PRNG or get its status
+
+=head1 SYNOPSIS
+
+ #include <openssl/rand.h>
+
+ int RAND_status(void);
+ int RAND_poll();
+
+ void RAND_add(const void *buf, int num, double randomness);
+ void RAND_seed(const void *buf, int num);
+
+ void RAND_keep_random_devices_open(int keep);
+
+Deprecated:
+
+ #if OPENSSL_API_COMPAT < 0x10100000L
+ int RAND_event(UINT iMsg, WPARAM wParam, LPARAM lParam);
+ void RAND_screen(void);
+ #endif
+
+=head1 DESCRIPTION
+
+These functions can be used to seed the random generator and to check its
+seeded state.
+In general, manual (re-)seeding of the default OpenSSL random generator
+(L<RAND_OpenSSL(3)>) is not necessary (but allowed), since it does (re-)seed
+itself automatically using trusted system entropy sources.
+This holds unless the default RAND_METHOD has been replaced or OpenSSL was
+built with automatic reseeding disabled, see L<RAND(7)> for more details.
+
+RAND_status() indicates whether or not the random generator has been sufficiently
+seeded. If not, functions such as L<RAND_bytes(3)> will fail.
+
+RAND_poll() uses the system's capabilities to seed the random generator using
+random input obtained from polling various trusted entropy sources.
+The default choice of the entropy source can be modified at build time,
+see L<RAND(7)> for more details.
+
+RAND_add() mixes the B<num> bytes at B<buf> into the internal state
+of the random generator.
+This function will not normally be needed, as mentioned above.
+The B<randomness> argument is an estimate of how much randomness is
+contained in
+B<buf>, in bytes, and should be a number between zero and B<num>.
+Details about sources of randomness and how to estimate their randomness
+can be found in the literature; for example [NIST SP 800-90B].
+The content of B<buf> cannot be recovered from subsequent random generator output.
+Applications that intend to save and restore random state in an external file
+should consider using L<RAND_load_file(3)> instead.
+
+RAND_seed() is equivalent to RAND_add() with B<randomness> set to B<num>.
+
+RAND_keep_random_devices_open() is used to control file descriptor
+usage by the random seed sources. Some seed sources maintain open file
+descriptors by default, which allows such sources to operate in a
+chroot(2) jail without the associated device nodes being available. When
+the B<keep> argument is zero, this call disables the retention of file
+descriptors. Conversely, a non-zero argument enables the retention of
+file descriptors. This function is usually called during initialization
+and it takes effect immediately.
+
+RAND_event() and RAND_screen() are equivalent to RAND_poll() and exist
+for compatibility reasons only. See HISTORY section below.
+
+=head1 RETURN VALUES
+
+RAND_status() returns 1 if the random generator has been seeded
+with enough data, 0 otherwise.
+
+RAND_poll() returns 1 if it generated seed data, 0 otherwise.
+
+RAND_event() returns RAND_status().
+
+The other functions do not return values.
+
+=head1 HISTORY
+
+RAND_event() and RAND_screen() were deprecated in OpenSSL 1.1.0 and should
+not be used.
+
+=head1 SEE ALSO
+
+L<RAND_bytes(3)>,
+L<RAND_egd(3)>,
+L<RAND_load_file(3)>,
+L<RAND(7)>
+
+=head1 COPYRIGHT
+
+Copyright 2000-2018 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