dsa - DSA key processing


   openssl dsa [-inform PEM|DER] [-outform PEM|DER] [-in filename]
   [-passin arg] [-out filename] [-passout arg] [-aes128] [-aes192]
   [-aes256] [-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


   -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).

       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.

       prints out the public, private key components and parameters.

       this option prevents output of the encoded version of the key.

       this option prints out the value of the public key component of the

       by default a private key is read from the input file: with this
       option a public key is read instead.

       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:


    -----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


   dsaparam(1), gendsa(1), rsa(1), genrsa(1)


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