openssl dsa

DSA key processing 

openssl command


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

Options

-inform DER|PEM 

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 

specifies the output format, the options have the same meaning as the -inform option.

-in filename 

specifies the input file name 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 

specifies the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in the openssl reference page.

-out filename 

specifies the output file name 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 file name should not be the same as the input file name.

-passout arg 

specifies the output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in the openssl reference page.

-des|-des3|-idea 

encrypts 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 used 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 

prevents output of the encoded version of the key.

-modulus 

prints out the value of the public key component of the key.

-pubin 

reads a public key from the input file. If this option is not specified, a private key is read from the input file.

-pubout 

outputs a public key. If this option is not specified, a private key is output. 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:

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

AVAILABILITY

PTC MKS Toolkit for System Administrators
PTC MKS Toolkit for Developers
PTC MKS Toolkit for Interoperability
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition


SEE ALSO

Commands:
openssl dsaparam, openssl gendsa, openssl genrsa, openssl rsa


PTC MKS Toolkit 10.2 Documentation Build 28.