5 openssl-dsa - DSA key processing
11 [B<-inform> B<DER>|B<PEM>]
12 [B<-outform> B<DER>|B<PEM>]
36 =for openssl ifdef pvk-string pvk-weak pvk-none engine
40 This command processes DSA keys. They can be converted between various
41 forms and their components printed out. B<Note> This command uses the
42 traditional SSLeay compatible format for private key encryption: newer
43 applications should use the more secure PKCS#8 format using the B<pkcs8>
51 Print out a usage message.
53 =item B<-inform> B<DER>|B<PEM>
55 This specifies the input format. The B<DER> option with a private key uses
56 an ASN1 DER encoded form of an ASN.1 SEQUENCE consisting of the values of
57 version (currently zero), p, q, g, the public and private key components
58 respectively as ASN.1 INTEGERs. When used with a public key it uses a
59 SubjectPublicKeyInfo structure: it is an error if the key is not DSA.
61 The B<PEM> form is the default format: it consists of the B<DER> format base64
62 encoded with additional header and footer lines. In the case of a private key
63 PKCS#8 format is also accepted.
65 =item B<-outform> B<DER>|B<PEM>
67 This specifies the output format, the options have the same meaning and default
68 as the B<-inform> option.
70 =item B<-in> I<filename>
72 This specifies the input filename to read a key from or standard input if this
73 option is not specified. If the key is encrypted a pass phrase will be
76 =item B<-out> I<filename>
78 This specifies the output filename to write a key to or standard output by
79 is not specified. If any encryption options are set then a pass phrase will be
80 prompted for. The output filename should B<not> be the same as the input
83 =item B<-passin> I<arg>, B<-passout> I<arg>
85 The password source for the input and output file.
86 For more information about the format of B<arg>
87 see L<openssl(1)/Pass Phrase Options>.
89 =item B<-aes128>, B<-aes192>, B<-aes256>, B<-aria128>, B<-aria192>, B<-aria256>, B<-camellia128>, B<-camellia192>, B<-camellia256>, B<-des>, B<-des3>, B<-idea>
91 These options encrypt the private key with the specified
92 cipher before outputting it. A pass phrase is prompted for.
93 If none of these options is specified the key is written in plain text. This
94 means that this command can be used to remove the pass phrase from a key
95 by not giving any encryption option is given, or to add or change the pass
96 phrase by setting them.
97 These options can only be used with PEM format output files.
101 Prints out the public, private key components and parameters.
105 This option prevents output of the encoded version of the key.
109 This option prints out the value of the public key component of the key.
113 By default, a private key is read from the input file. With this option a
114 public key is read instead.
118 By default, a private key is output. With this option a public
119 key will be output instead. This option is automatically set if the input is
122 =item B<-engine> I<id>
124 Specifying an engine (by its unique I<id> string) will cause L<openssl-dsa(1)>
125 to attempt to obtain a functional reference to the specified engine,
126 thus initialising it if needed. The engine will then be set as the default
127 for all available algorithms.
133 The PEM private key format uses the header and footer lines:
135 -----BEGIN DSA PRIVATE KEY-----
136 -----END DSA PRIVATE KEY-----
138 The PEM public key format uses the header and footer lines:
140 -----BEGIN PUBLIC KEY-----
141 -----END PUBLIC KEY-----
145 To remove the pass phrase on a DSA private key:
147 openssl dsa -in key.pem -out keyout.pem
149 To encrypt a private key using triple DES:
151 openssl dsa -in key.pem -des3 -out keyout.pem
153 To convert a private key from PEM to DER format:
155 openssl dsa -in key.pem -outform DER -out keyout.der
157 To print out the components of a private key to standard output:
159 openssl dsa -in key.pem -text -noout
161 To just output the public part of a private key:
163 openssl dsa -in key.pem -pubout -out pubkey.pem
168 L<openssl-dsaparam(1)>,
169 L<openssl-gendsa(1)>,
175 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
177 Licensed under the Apache License 2.0 (the "License"). You may not use
178 this file except in compliance with the License. You can obtain a copy
179 in the file LICENSE in the source distribution or at
180 L<https://www.openssl.org/source/license.html>.