OpenSSL

Cryptography and SSL/TLS Toolkit

openssl-dsa

NAME

openssl-dsa - DSA key processing

SYNOPSIS

openssl dsa [-help] [-inform DER|PEM] [-outform DER|PEM] [-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

This 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, -outform DER|PEM

The input and formats; the default is PEM. See "Format Options" in openssl(1) for details.

Private keys are a sequence of ASN.1 INTEGERS: the version (zero), p, q, g, and the public and and private key components. Public keys are a SubjectPublicKeyInfo structure with the DSA type.

The PEM format also accepts PKCS#8 data.

-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.

-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.

-passin arg, -passout arg

The password source for the input and output file. For more information about the format of arg see "Pass Phrase Options" 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 this command can be used to remove the pass phrase from a key by not giving any encryption option is given, or to add or change the pass phrase by setting them. 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 openssl-dsa(1) 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.

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

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

Copyright 2000-2019 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 https://www.openssl.org/source/license.html.