=pod

=head1 NAME

openssl-dsaparam,
dsaparam - DSA parameter manipulation and generation

=head1 SYNOPSIS

B<openssl dsaparam>
[B<-help>]
[B<-inform DER|PEM>]
[B<-outform DER|PEM>]
[B<-in filename>]
[B<-out filename>]
[B<-noout>]
[B<-text>]
[B<-C>]
[B<-rand file...>]
[B<-writerand file>]
[B<-genkey>]
[B<-engine id>]
[B<-verbose>]
[B<numbits>]

=head1 DESCRIPTION

This command is used to manipulate or generate DSA parameter files.

=head1 OPTIONS

=over 4

=item B<-help>

Print out a usage message.

=item B<-inform DER|PEM>

This specifies the input format. The B<DER> option uses an ASN1 DER encoded
form compatible with RFC2459 (PKIX) DSS-Parms that is a SEQUENCE consisting
of p, q and g respectively. The PEM form is the default format: it consists
of the B<DER> format base64 encoded with additional header and footer lines.

=item B<-outform DER|PEM>

This specifies the output format, the options have the same meaning and default
as the B<-inform> option.

=item B<-in filename>

This specifies the input filename to read parameters from or standard input if
this option is not specified. If the B<numbits> parameter is included then
this option will be ignored.

=item B<-out filename>

This specifies the output filename parameters to. Standard output is used
if this option is not present. The output filename should B<not> be the same
as the input filename.

=item B<-noout>

This option inhibits the output of the encoded version of the parameters.

=item B<-text>

This option prints out the DSA parameters in human readable form.

=item B<-C>

This option converts the parameters into C code. The parameters can then
be loaded by calling the get_dsaXXX() function.

=item B<-genkey>

This option will generate a DSA either using the specified or generated
parameters.

=item B<-rand file...>

A file or files containing random data used to seed the random number
generator.
Multiple files can be specified separated by an OS-dependent character.
The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
all others.

=item [B<-writerand file>]

Writes random data to the specified I<file> upon exit.
This can be used with a subsequent B<-rand> flag.

=item B<-engine id>

Specifying an engine (by its unique B<id> string) will cause B<dsaparam>
to attempt to obtain a functional reference to the specified engine,
thus initialising it if needed. The engine will then be set as the default
for all available algorithms.

=item B<-verbose>

Print extra details about the operations being performed.

=item B<numbits>

This option specifies that a parameter set should be generated of size
B<numbits>. It must be the last option. If this option is included then
the input file (if any) is ignored.

=back

=head1 NOTES

PEM format DSA parameters use the header and footer lines:

 -----BEGIN DSA PARAMETERS-----
 -----END DSA PARAMETERS-----

DSA parameter generation is a slow process and as a result the same set of
DSA parameters is often used to generate several distinct keys.

=head1 SEE ALSO

L<gendsa(1)>, L<dsa(1)>, L<genrsa(1)>,
L<rsa(1)>

=head1 COPYRIGHT

Copyright 2000-2017 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
