Linux "dsa" Command Line Options and Examples
DSA key processing
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.
openssl dsa [-help] [-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]
Command Line Options:
Print out a usage message.
dsa -help ...
This specifies the input format. The DER option with a private key uses an ASN1 DER encoded form of an ASN.1 SEQUENCE consistingof the values of version (currently zero), p, q, g, the public and private key components respectively as ASN.1 INTEGERs. Whenused 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 thecase of a private key PKCS#8 format is also accepted.
dsa -inform ...
This specifies the output format, the options have the same meaning as the -inform option.
dsa -outform ...
This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted apass phrase will be prompted for.
dsa -in ...
the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
dsa -passin ...
This specifies the output filename to write a key to or standard output by is not specified. If any encryption options are setthen a pass phrase will be prompted for. The output filename should not be the same as the input filename.
dsa -out ...
the output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section inopenssl(1).
dsa -passout ...
These options encrypt the private key with the specified cipher before outputting it. A pass phrase is prompted for. If none ofthese options is specified the key is written in plain text. This means that using the dsa utility to read in an encrypted keywith no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use toadd or change the pass phrase. These options can only be used with PEM format output files.
dsa -aes128|-aes192|-aes256|-camellia128|-camellia192|-camellia256|-des|-des3|-idea ...
prints out the public, private key components and parameters.
dsa -text ...
this option prevents output of the encoded version of the key.
dsa -noout ...
this option prints out the value of the public key component of the key.
dsa -modulus ...
by default a private key is read from the input file: with this option a public key is read instead.
dsa -pubin ...
by default a private key is output. With this option a public key will be output instead. This option is automatically set if theinput is a public key.
dsa -pubout ...
specifying an engine (by its unique id string) will cause dsa to attempt to obtain a functional reference to the specifiedengine, thus initialising it if needed. The engine will then be set as the default for all available algorithms.NOTESThe PEM private key format uses the header and footer lines:
dsa -engine ...