dsa(1)

     DSA(1)                 0.9.6h (2000-02-16)                 DSA(1)

     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]

     DESCRIPTION
          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.

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          -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.

     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:

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           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)

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