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
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).
-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 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:
