DragonFly On-Line Manual Pages

DSA(1)				    OpenSSL				DSA(1)

NAME
       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
       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).

       -aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-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)

1.0.2h				  2016-05-03				DSA(1)