1=pod 2{- OpenSSL::safe::output_do_not_edit_headers(); -} 3 4=head1 NAME 5 6openssl-rand - generate pseudo-random bytes 7 8=head1 SYNOPSIS 9 10B<openssl rand> 11[B<-help>] 12[B<-out> I<file>] 13[B<-base64>] 14[B<-hex>] 15{- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_r_synopsis -} 16{- $OpenSSL::safe::opt_provider_synopsis -} 17I<num> 18 19=head1 DESCRIPTION 20 21This command generates I<num> random bytes using a cryptographically 22secure pseudo random number generator (CSPRNG). 23 24The random bytes are generated using the L<RAND_bytes(3)> function, 25which provides a security level of 256 bits, provided it managed to 26seed itself successfully from a trusted operating system entropy source. 27Otherwise, the command will fail with a nonzero error code. 28For more details, see L<RAND_bytes(3)>, L<RAND(7)>, and L<EVP_RAND(7)>. 29 30=head1 OPTIONS 31 32=over 4 33 34=item B<-help> 35 36Print out a usage message. 37 38=item B<-out> I<file> 39 40Write to I<file> instead of standard output. 41 42=item B<-base64> 43 44Perform base64 encoding on the output. 45 46=item B<-hex> 47 48Show the output as a hex string. 49 50{- $OpenSSL::safe::opt_engine_item -} 51 52{- $OpenSSL::safe::opt_r_item -} 53 54{- $OpenSSL::safe::opt_provider_item -} 55 56=back 57 58=head1 SEE ALSO 59 60L<openssl(1)>, 61L<RAND_bytes(3)>, 62L<RAND(7)>, 63L<EVP_RAND(7)> 64 65=head1 HISTORY 66 67The B<-engine> option was deprecated in OpenSSL 3.0. 68 69=head1 COPYRIGHT 70 71Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. 72 73Licensed under the Apache License 2.0 (the "License"). You may not use 74this file except in compliance with the License. You can obtain a copy 75in the file LICENSE in the source distribution or at 76L<https://www.openssl.org/source/license.html>. 77 78=cut 79