it must also indicate an error by returning a buffer length of 0.
See NOTES section for more details.
-The B<cleanup_entropy>() callback is called from the B<drbg> to to clear and
+The B<cleanup_entropy>() callback is called from the B<drbg> to clear and
free the buffer allocated previously by get_entropy().
The values B<out> and B<outlen> are the random buffer's address and length,
as returned by the get_entropy() callback.
=head1 COPYRIGHT
-Copyright 2017-2019 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2017-2020 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