NAME
    dsa - DSA key processing

SYNOPSIS
    openssl dsa [-inform PEM|DER] [-outform PEM|DER] [-in filename]
    [-passin arg] [-out filename] [-passout arg] [-des] [-des3] [-idea]
    [-text] [-noout] [-modulus] [-pubin] [-pubout] [-engine id]

DESCRIPTION
    The dsa command processes DSA keys. They can be converted between vari-
    ous 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 for-
   mat 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 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:

 -----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)