openssl-dsa, dsa - DSA key processing
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]
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
- -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 "Pass Phrase Options" 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 "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 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.
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-----
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
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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>.