1=pod
2
3=head1 NAME
4
5openssl-dsaparam,
6dsaparam - DSA parameter manipulation and generation
7
8=head1 SYNOPSIS
9
10B<openssl dsaparam>
11[B<-help>]
12[B<-inform DER|PEM>]
13[B<-outform DER|PEM>]
14[B<-in filename>]
15[B<-out filename>]
16[B<-noout>]
17[B<-text>]
18[B<-C>]
19[B<-rand file...>]
20[B<-writerand file>]
21[B<-genkey>]
22[B<-engine id>]
23[B<numbits>]
24
25=head1 DESCRIPTION
26
27This command is used to manipulate or generate DSA parameter files.
28
29=head1 OPTIONS
30
31=over 4
32
33=item B<-help>
34
35Print out a usage message.
36
37=item B<-inform DER|PEM>
38
39This specifies the input format. The B<DER> option uses an ASN1 DER encoded
40form compatible with RFC2459 (PKIX) DSS-Parms that is a SEQUENCE consisting
41of p, q and g respectively. The PEM form is the default format: it consists
42of the B<DER> format base64 encoded with additional header and footer lines.
43
44=item B<-outform DER|PEM>
45
46This specifies the output format, the options have the same meaning and default
47as the B<-inform> option.
48
49=item B<-in filename>
50
51This specifies the input filename to read parameters from or standard input if
52this option is not specified. If the B<numbits> parameter is included then
53this option will be ignored.
54
55=item B<-out filename>
56
57This specifies the output filename parameters to. Standard output is used
58if this option is not present. The output filename should B<not> be the same
59as the input filename.
60
61=item B<-noout>
62
63This option inhibits the output of the encoded version of the parameters.
64
65=item B<-text>
66
67This option prints out the DSA parameters in human readable form.
68
69=item B<-C>
70
71This option converts the parameters into C code. The parameters can then
72be loaded by calling the get_dsaXXX() function.
73
74=item B<-genkey>
75
76This option will generate a DSA either using the specified or generated
77parameters.
78
79=item B<-rand file...>
80
81A file or files containing random data used to seed the random number
82generator.
83Multiple files can be specified separated by an OS-dependent character.
84The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
85all others.
86
87=item [B<-writerand file>]
88
89Writes random data to the specified I<file> upon exit.
90This can be used with a subsequent B<-rand> flag.
91
92=item B<numbits>
93
94This option specifies that a parameter set should be generated of size
95B<numbits>. It must be the last option. If this option is included then
96the input file (if any) is ignored.
97
98=item B<-engine id>
99
100Specifying an engine (by its unique B<id> string) will cause B<dsaparam>
101to attempt to obtain a functional reference to the specified engine,
102thus initialising it if needed. The engine will then be set as the default
103for all available algorithms.
104
105=back
106
107=head1 NOTES
108
109PEM format DSA parameters use the header and footer lines:
110
111 -----BEGIN DSA PARAMETERS-----
112 -----END DSA PARAMETERS-----
113
114DSA parameter generation is a slow process and as a result the same set of
115DSA parameters is often used to generate several distinct keys.
116
117=head1 SEE ALSO
118
119L<gendsa(1)>, L<dsa(1)>, L<genrsa(1)>,
120L<rsa(1)>
121
122=head1 COPYRIGHT
123
124Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
125
126Licensed under the OpenSSL license (the "License").  You may not use
127this file except in compliance with the License.  You can obtain a copy
128in the file LICENSE in the source distribution or at
129L<https://www.openssl.org/source/license.html>.
130
131=cut
132