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
COMMAND OPTIONS
-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 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 PASSPHRASEARGUMENTS 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 PASSPHRASEARGUMENTS section in openssl(1).
-des|-des3|-idea
These options encrypt the private key with the DES, triple DES, or the
IDEA ciphers respectively 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 it's unique id string) will cause req
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:
