NAME

       openssl-dsa, dsa - DSA key processing

SYNOPSIS

       openssl dsa [-help] [-inform PEM|DER] [-outform PEM|DER] [-in filename] [-passin arg] [-out filename]
       [-passout arg] [-aes128] [-aes192] [-aes256] [-aria128] [-aria192] [-aria256] [-camellia128]
       [-camellia192] [-camellia256] [-des] [-des3] [-idea] [-text] [-noout] [-modulus] [-pubin] [-pubout]
       [-engine id]

DESCRIPTION

       The dsa command processes DSA keys. They can be converted between various forms and their components
       printed out. Note This command uses the traditional SSLeay compatible format for private key encryption:
       newer applications should use the more secure PKCS#8 format using the pkcs8

OPTIONS

       -help
           Print out a usage message.

       -inform DER|PEM
           This  specifies  the input format. The DER option with a private key uses an ASN1 DER encoded form of
           an ASN.1 SEQUENCE consisting of the values of version (currently zero),  p,  q,  g,  the  public  and
           private  key  components  respectively  as  ASN.1  INTEGERs.  When  used  with a public key it uses a
           SubjectPublicKeyInfo structure: it is an error if the key is not DSA.

           The PEM form is the default format: it consists of the DER  format  base64  encoded  with  additional
           header and footer lines. In the case of a private key PKCS#8 format is also accepted.

       -outform DER|PEM
           This  specifies  the  output  format,  the  options  have the same meaning and default as the -inform
           option.

       -in filename
           This specifies the input filename to read a key  from  or  standard  input  if  this  option  is  not
           specified. If the key is encrypted a pass phrase will be prompted for.

       -passin arg
           The  input  file  password  source.  For more information about the format of arg see the PASS PHRASE
           ARGUMENTS section in openssl(1).

       -out filename
           This specifies the output filename to write a key to or standard output by is not specified.  If  any
           encryption options are set then a pass phrase will be prompted for. The output filename should not be
           the same as the input filename.

       -passout arg
           The  output  file  password  source. For more information about the format of arg see the PASS PHRASE
           ARGUMENTS section in openssl(1).

       -aes128, -aes192, -aes256, -aria128, -aria192, -aria256, -camellia128, -camellia192, -camellia256, -des,
       -des3, -idea
           These options encrypt the private key with the specified cipher before outputting it. A  pass  phrase
           is  prompted for.  If none of these options is specified the key is written in plain text. This means
           that using the dsa utility to read in an encrypted key with no  encryption  option  can  be  used  to
           remove  the  pass  phrase  from  a  key, or by setting the encryption options it can be use to add or
           change the pass phrase.  These options can only be used with PEM format output files.

       -text
           Prints out the public, private key components and parameters.

       -noout
           This option prevents output of the encoded version of the key.

       -modulus
           This option prints out the value of the public key component of the key.

       -pubin
           By default, a private key is read from the input file. With this option a public key is read instead.

       -pubout
           By default, a private key is output. With this option a public  key  will  be  output  instead.  This
           option is automatically set if the input is a public key.

       -engine id
           Specifying  an  engine  (by  its  unique  id string) will cause dsa 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.

NOTES

       The PEM private key format uses the header and footer lines:

        -----BEGIN DSA PRIVATE KEY-----

        -----END DSA PRIVATE KEY-----
       The PEM public key format uses the header and footer lines:

        -----BEGIN PUBLIC KEY-----

        -----END PUBLIC KEY-----

EXAMPLES

       To remove the pass phrase on a DSA private key:

        openssl dsa -in key.pem -out keyout.pem

       To encrypt a private key using triple DES:

        openssl dsa -in key.pem -des3 -out keyout.pem

       To convert a private key from PEM to DER format:

        openssl dsa -in key.pem -outform DER -out keyout.der

       To print out the components of a private key to standard output:

        openssl dsa -in key.pem -text -noout

       To just output the public part of a private key:

        openssl dsa -in key.pem -pubout -out pubkey.pem

SEE ALSO

       dsaparam(1), gendsa(1), rsa(1), genrsa(1)

COPYRIGHT

       Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (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
       <https://www.openssl.org/source/license.html>.

1.1.1f                                             2025-02-05                                          DSA(1SSL)