Initial Commit

openssl-1.0.2f/doc/apps/dsa.pod

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+=pod
+
+=head1 NAME
+
+dsa - DSA key processing
+
+=head1 SYNOPSIS
+
+B<openssl> B<dsa>
+[B<-inform PEM|DER>]
+[B<-outform PEM|DER>]
+[B<-in filename>]
+[B<-passin arg>]
+[B<-out filename>]
+[B<-passout arg>]
+[B<-aes128>]
+[B<-aes192>]
+[B<-aes256>]
+[B<-camellia128>]
+[B<-camellia192>]
+[B<-camellia256>]
+[B<-des>]
+[B<-des3>]
+[B<-idea>]
+[B<-text>]
+[B<-noout>]
+[B<-modulus>]
+[B<-pubin>]
+[B<-pubout>]
+[B<-engine id>]
+
+=head1 DESCRIPTION
+
+The B<dsa> command processes DSA keys. They can be converted between various
+forms and their components printed out. B<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 B<pkcs8>
+
+=head1 COMMAND OPTIONS
+
+=over 4
+
+=item B<-inform DER|PEM>
+
+This specifies the input format. The B<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 B<PEM> form is the default format: it consists of the B<DER> format base64
+encoded with additional header and footer lines. In the case of a private key
+PKCS#8 format is also accepted.
+
+=item B<-outform DER|PEM>
+
+This specifies the output format, the options have the same meaning as the 
+B<-inform> option.
+
+=item B<-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.
+
+=item B<-passin arg>
+
+the input file password source. For more information about the format of B<arg>
+see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
+
+=item B<-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 B<not> be the same as the input
+filename.
+
+=item B<-passout arg>
+
+the output file password source. For more information about the format of B<arg>
+see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
+
+=item B<-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 B<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.
+
+=item B<-text>
+
+prints out the public, private key components and parameters.
+
+=item B<-noout>
+
+this option prevents output of the encoded version of the key.
+
+=item B<-modulus>
+
+this option prints out the value of the public key component of the key.
+
+=item B<-pubin>
+
+by default a private key is read from the input file: with this option a
+public key is read instead.
+
+=item B<-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.
+
+=item B<-engine id>
+
+specifying an engine (by its unique B<id> string) will cause B<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.
+
+=back
+
+=head1 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-----
+
+=head1 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
+
+=head1 SEE ALSO
+
+L<dsaparam(1)|dsaparam(1)>, L<gendsa(1)|gendsa(1)>, L<rsa(1)|rsa(1)>,
+L<genrsa(1)|genrsa(1)>
+
+=cut