xref: /freebsd/crypto/openssl/doc/man1/openssl-rand.pod.in (revision b077aed33b7b6aefca7b17ddb250cf521f938613)
1*b077aed3SPierre Pronchery=pod
2*b077aed3SPierre Pronchery{- OpenSSL::safe::output_do_not_edit_headers(); -}
3*b077aed3SPierre Pronchery
4*b077aed3SPierre Pronchery=head1 NAME
5*b077aed3SPierre Pronchery
6*b077aed3SPierre Proncheryopenssl-rand - generate pseudo-random bytes
7*b077aed3SPierre Pronchery
8*b077aed3SPierre Pronchery=head1 SYNOPSIS
9*b077aed3SPierre Pronchery
10*b077aed3SPierre ProncheryB<openssl rand>
11*b077aed3SPierre Pronchery[B<-help>]
12*b077aed3SPierre Pronchery[B<-out> I<file>]
13*b077aed3SPierre Pronchery[B<-base64>]
14*b077aed3SPierre Pronchery[B<-hex>]
15*b077aed3SPierre Pronchery{- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_r_synopsis -}
16*b077aed3SPierre Pronchery{- $OpenSSL::safe::opt_provider_synopsis -}
17*b077aed3SPierre ProncheryI<num>
18*b077aed3SPierre Pronchery
19*b077aed3SPierre Pronchery=head1 DESCRIPTION
20*b077aed3SPierre Pronchery
21*b077aed3SPierre ProncheryThis command generates I<num> random bytes using a cryptographically
22*b077aed3SPierre Proncherysecure pseudo random number generator (CSPRNG).
23*b077aed3SPierre Pronchery
24*b077aed3SPierre ProncheryThe random bytes are generated using the L<RAND_bytes(3)> function,
25*b077aed3SPierre Proncherywhich provides a security level of 256 bits, provided it managed to
26*b077aed3SPierre Proncheryseed itself successfully from a trusted operating system entropy source.
27*b077aed3SPierre ProncheryOtherwise, the command will fail with a nonzero error code.
28*b077aed3SPierre ProncheryFor more details, see L<RAND_bytes(3)>, L<RAND(7)>, and L<EVP_RAND(7)>.
29*b077aed3SPierre Pronchery
30*b077aed3SPierre Pronchery=head1 OPTIONS
31*b077aed3SPierre Pronchery
32*b077aed3SPierre Pronchery=over 4
33*b077aed3SPierre Pronchery
34*b077aed3SPierre Pronchery=item B<-help>
35*b077aed3SPierre Pronchery
36*b077aed3SPierre ProncheryPrint out a usage message.
37*b077aed3SPierre Pronchery
38*b077aed3SPierre Pronchery=item B<-out> I<file>
39*b077aed3SPierre Pronchery
40*b077aed3SPierre ProncheryWrite to I<file> instead of standard output.
41*b077aed3SPierre Pronchery
42*b077aed3SPierre Pronchery=item B<-base64>
43*b077aed3SPierre Pronchery
44*b077aed3SPierre ProncheryPerform base64 encoding on the output.
45*b077aed3SPierre Pronchery
46*b077aed3SPierre Pronchery=item B<-hex>
47*b077aed3SPierre Pronchery
48*b077aed3SPierre ProncheryShow the output as a hex string.
49*b077aed3SPierre Pronchery
50*b077aed3SPierre Pronchery{- $OpenSSL::safe::opt_engine_item -}
51*b077aed3SPierre Pronchery
52*b077aed3SPierre Pronchery{- $OpenSSL::safe::opt_r_item -}
53*b077aed3SPierre Pronchery
54*b077aed3SPierre Pronchery{- $OpenSSL::safe::opt_provider_item -}
55*b077aed3SPierre Pronchery
56*b077aed3SPierre Pronchery=back
57*b077aed3SPierre Pronchery
58*b077aed3SPierre Pronchery=head1 SEE ALSO
59*b077aed3SPierre Pronchery
60*b077aed3SPierre ProncheryL<openssl(1)>,
61*b077aed3SPierre ProncheryL<RAND_bytes(3)>,
62*b077aed3SPierre ProncheryL<RAND(7)>,
63*b077aed3SPierre ProncheryL<EVP_RAND(7)>
64*b077aed3SPierre Pronchery
65*b077aed3SPierre Pronchery=head1 HISTORY
66*b077aed3SPierre Pronchery
67*b077aed3SPierre ProncheryThe B<-engine> option was deprecated in OpenSSL 3.0.
68*b077aed3SPierre Pronchery
69*b077aed3SPierre Pronchery=head1 COPYRIGHT
70*b077aed3SPierre Pronchery
71*b077aed3SPierre ProncheryCopyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
72*b077aed3SPierre Pronchery
73*b077aed3SPierre ProncheryLicensed under the Apache License 2.0 (the "License").  You may not use
74*b077aed3SPierre Proncherythis file except in compliance with the License.  You can obtain a copy
75*b077aed3SPierre Proncheryin the file LICENSE in the source distribution or at
76*b077aed3SPierre ProncheryL<https://www.openssl.org/source/license.html>.
77*b077aed3SPierre Pronchery
78*b077aed3SPierre Pronchery=cut
79