Mac Developer Library Developer
Search

 

This manual page is for Mac OS X version 10.9

If you are running a different version of Mac OS X, view the documentation locally:

  • In Terminal, using the man(1) command

Reading manual pages

Manual pages are intended as a quick reference for people who already understand a technology.

  • To learn how the manual is organized or to learn about command syntax, read the manual page for manpages(5).

  • For more information about this technology, look for other documentation in the Apple Developer Library.

  • For general information about writing shell scripts, read Shell Scripting Primer.



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] [-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).

       -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 KEY---------END
        -----END DSA PRIVATE KEY-----The KEY----The

       The PEM public key format uses the header and footer lines:

        -----BEGIN PUBLIC KEY----------END KEY---------END
        -----END PUBLIC KEY-----EXAMPLES KEY----EXAMPLES

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)



50                                               2013-03-05                                           DSA(1)

Reporting Problems

The way to report a problem with this manual page depends on the type of problem:

Content errors
Report errors in the content of this documentation to the OpenSSL project by sending email to openssl-bugs@openssl.org.
Bug reports
Report bugs in the functionality of the described tool or API to Apple through Bug Reporter and to the OpenSSL project by sending email to openssl-bugs@openssl.org.
Formatting problems
Report formatting mistakes in the online version of these pages with the feedback links below.

Feedback