1*2175Sjp161948=pod 2*2175Sjp161948 3*2175Sjp161948=head1 NAME 4*2175Sjp161948 5*2175Sjp161948dsa - DSA key processing 6*2175Sjp161948 7*2175Sjp161948=head1 SYNOPSIS 8*2175Sjp161948 9*2175Sjp161948B<openssl> B<dsa> 10*2175Sjp161948[B<-inform PEM|DER>] 11*2175Sjp161948[B<-outform PEM|DER>] 12*2175Sjp161948[B<-in filename>] 13*2175Sjp161948[B<-passin arg>] 14*2175Sjp161948[B<-out filename>] 15*2175Sjp161948[B<-passout arg>] 16*2175Sjp161948[B<-des>] 17*2175Sjp161948[B<-des3>] 18*2175Sjp161948[B<-idea>] 19*2175Sjp161948[B<-text>] 20*2175Sjp161948[B<-noout>] 21*2175Sjp161948[B<-modulus>] 22*2175Sjp161948[B<-pubin>] 23*2175Sjp161948[B<-pubout>] 24*2175Sjp161948[B<-engine id>] 25*2175Sjp161948 26*2175Sjp161948=head1 DESCRIPTION 27*2175Sjp161948 28*2175Sjp161948The B<dsa> command processes DSA keys. They can be converted between various 29*2175Sjp161948forms and their components printed out. B<Note> This command uses the 30*2175Sjp161948traditional SSLeay compatible format for private key encryption: newer 31*2175Sjp161948applications should use the more secure PKCS#8 format using the B<pkcs8> 32*2175Sjp161948 33*2175Sjp161948=head1 COMMAND OPTIONS 34*2175Sjp161948 35*2175Sjp161948=over 4 36*2175Sjp161948 37*2175Sjp161948=item B<-inform DER|PEM> 38*2175Sjp161948 39*2175Sjp161948This specifies the input format. The B<DER> option with a private key uses 40*2175Sjp161948an ASN1 DER encoded form of an ASN.1 SEQUENCE consisting of the values of 41*2175Sjp161948version (currently zero), p, q, g, the public and private key components 42*2175Sjp161948respectively as ASN.1 INTEGERs. When used with a public key it uses a 43*2175Sjp161948SubjectPublicKeyInfo structure: it is an error if the key is not DSA. 44*2175Sjp161948 45*2175Sjp161948The B<PEM> form is the default format: it consists of the B<DER> format base64 46*2175Sjp161948encoded with additional header and footer lines. In the case of a private key 47*2175Sjp161948PKCS#8 format is also accepted. 48*2175Sjp161948 49*2175Sjp161948=item B<-outform DER|PEM> 50*2175Sjp161948 51*2175Sjp161948This specifies the output format, the options have the same meaning as the 52*2175Sjp161948B<-inform> option. 53*2175Sjp161948 54*2175Sjp161948=item B<-in filename> 55*2175Sjp161948 56*2175Sjp161948This specifies the input filename to read a key from or standard input if this 57*2175Sjp161948option is not specified. If the key is encrypted a pass phrase will be 58*2175Sjp161948prompted for. 59*2175Sjp161948 60*2175Sjp161948=item B<-passin arg> 61*2175Sjp161948 62*2175Sjp161948the input file password source. For more information about the format of B<arg> 63*2175Sjp161948see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 64*2175Sjp161948 65*2175Sjp161948=item B<-out filename> 66*2175Sjp161948 67*2175Sjp161948This specifies the output filename to write a key to or standard output by 68*2175Sjp161948is not specified. If any encryption options are set then a pass phrase will be 69*2175Sjp161948prompted for. The output filename should B<not> be the same as the input 70*2175Sjp161948filename. 71*2175Sjp161948 72*2175Sjp161948=item B<-passout arg> 73*2175Sjp161948 74*2175Sjp161948the output file password source. For more information about the format of B<arg> 75*2175Sjp161948see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 76*2175Sjp161948 77*2175Sjp161948=item B<-des|-des3|-idea> 78*2175Sjp161948 79*2175Sjp161948These options encrypt the private key with the DES, triple DES, or the 80*2175Sjp161948IDEA ciphers respectively before outputting it. A pass phrase is prompted for. 81*2175Sjp161948If none of these options is specified the key is written in plain text. This 82*2175Sjp161948means that using the B<dsa> utility to read in an encrypted key with no 83*2175Sjp161948encryption option can be used to remove the pass phrase from a key, or by 84*2175Sjp161948setting the encryption options it can be use to add or change the pass phrase. 85*2175Sjp161948These options can only be used with PEM format output files. 86*2175Sjp161948 87*2175Sjp161948=item B<-text> 88*2175Sjp161948 89*2175Sjp161948prints out the public, private key components and parameters. 90*2175Sjp161948 91*2175Sjp161948=item B<-noout> 92*2175Sjp161948 93*2175Sjp161948this option prevents output of the encoded version of the key. 94*2175Sjp161948 95*2175Sjp161948=item B<-modulus> 96*2175Sjp161948 97*2175Sjp161948this option prints out the value of the public key component of the key. 98*2175Sjp161948 99*2175Sjp161948=item B<-pubin> 100*2175Sjp161948 101*2175Sjp161948by default a private key is read from the input file: with this option a 102*2175Sjp161948public key is read instead. 103*2175Sjp161948 104*2175Sjp161948=item B<-pubout> 105*2175Sjp161948 106*2175Sjp161948by default a private key is output. With this option a public 107*2175Sjp161948key will be output instead. This option is automatically set if the input is 108*2175Sjp161948a public key. 109*2175Sjp161948 110*2175Sjp161948=item B<-engine id> 111*2175Sjp161948 112*2175Sjp161948specifying an engine (by it's unique B<id> string) will cause B<req> 113*2175Sjp161948to attempt to obtain a functional reference to the specified engine, 114*2175Sjp161948thus initialising it if needed. The engine will then be set as the default 115*2175Sjp161948for all available algorithms. 116*2175Sjp161948 117*2175Sjp161948=back 118*2175Sjp161948 119*2175Sjp161948=head1 NOTES 120*2175Sjp161948 121*2175Sjp161948The PEM private key format uses the header and footer lines: 122*2175Sjp161948 123*2175Sjp161948 -----BEGIN DSA PRIVATE KEY----- 124*2175Sjp161948 -----END DSA PRIVATE KEY----- 125*2175Sjp161948 126*2175Sjp161948The PEM public key format uses the header and footer lines: 127*2175Sjp161948 128*2175Sjp161948 -----BEGIN PUBLIC KEY----- 129*2175Sjp161948 -----END PUBLIC KEY----- 130*2175Sjp161948 131*2175Sjp161948=head1 EXAMPLES 132*2175Sjp161948 133*2175Sjp161948To remove the pass phrase on a DSA private key: 134*2175Sjp161948 135*2175Sjp161948 openssl dsa -in key.pem -out keyout.pem 136*2175Sjp161948 137*2175Sjp161948To encrypt a private key using triple DES: 138*2175Sjp161948 139*2175Sjp161948 openssl dsa -in key.pem -des3 -out keyout.pem 140*2175Sjp161948 141*2175Sjp161948To convert a private key from PEM to DER format: 142*2175Sjp161948 143*2175Sjp161948 openssl dsa -in key.pem -outform DER -out keyout.der 144*2175Sjp161948 145*2175Sjp161948To print out the components of a private key to standard output: 146*2175Sjp161948 147*2175Sjp161948 openssl dsa -in key.pem -text -noout 148*2175Sjp161948 149*2175Sjp161948To just output the public part of a private key: 150*2175Sjp161948 151*2175Sjp161948 openssl dsa -in key.pem -pubout -out pubkey.pem 152*2175Sjp161948 153*2175Sjp161948=head1 SEE ALSO 154*2175Sjp161948 155*2175Sjp161948L<dsaparam(1)|dsaparam(1)>, L<gendsa(1)|gendsa(1)>, L<rsa(1)|rsa(1)>, 156*2175Sjp161948L<genrsa(1)|genrsa(1)> 157*2175Sjp161948 158*2175Sjp161948=cut 159