MAN page from Trustix openssl-0.9.7c-3tr.i586.rpm
Section: OpenSSL (1)
dsa - DSA key processing
command processes DSA
keys. They can be converted between variousforms and their components printed out. Note
This command uses thetraditional SSLeay compatible format for private key encryption: newerapplications should use the more secure PKCS#8 format using the pkcs8
- -inform DER|PEM
- This specifies the input format. The DER option with a private key usesan ASN1 DER encoded form of an ASN.1 SEQUENCE consisting of the values ofversion (currently zero), p, q, g, the public and private key componentsrespectively as ASN.1 INTEGERs. When used with a public key it uses aSubjectPublicKeyInfo structure: it is an error if the key is not DSA.
The PEM form is the default format: it consists of the DER format base64encoded with additional header and footer lines. In the case of a private keyPKCS#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 thisoption is not specified. If the key is encrypted a pass phrase will beprompted for.
- -passin arg
- the input file password source. For more information about the format of argsee the PASS PHRASE ARGUMENTS section in openssl(1).
- -out filename
- This specifies the output filename to write a key to or standard output byis not specified. If any encryption options are set then a pass phrase will beprompted for. The output filename should not be the same as the inputfilename.
- -passout arg
- the output file password source. For more information about the format of argsee the PASS PHRASE ARGUMENTS section in openssl(1).
- 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. Thismeans that using the dsa utility to read in an encrypted key with noencryption option can be used to remove the pass phrase from a key, or bysetting 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 key.
- by default a private key is read from the input file: with this option apublic key is read instead.
- by default a private key is output. With this option a publickey will be output instead. This option is automatically set if the input isa public key.
- -engine id
- specifying an engine (by it's unique id string) will cause reqto attempt to obtain a functional reference to the specified engine,thus initialising it if needed. The engine will then be set as the defaultfor all available algorithms.
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-----
To remove the pass phrase on a DSA
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
- COMMAND OPTIONS
- SEE ALSO
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