/usr/man2/cat.1/dsa.1.Z(/usr/man2/cat.1/dsa.1.Z)

NAME

       openssl-dsa, dsa - DSA key processing

SYNOPSIS

       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]

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).

       -aes128|-aes192|-aes256|-camellia128|-camellia192|-camel-
       lia256|-des|-des3|-idea
           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.

       -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:

        -----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)

1.0.2t                            2019-09-10                            DSA(1)
See also openssl-dsa(1)