package Crypt::OpenSSL::DSA;
use strict;
use warnings;
require DynaLoader;
use vars qw(@ISA $VERSION);
@ISA = qw(DynaLoader);
$VERSION = '0.16';
bootstrap Crypt::OpenSSL::DSA $VERSION;
sub read_pub_key_str {
my ($class, $key_str) = @_;
$class->_load_key(0, $key_str);
}
sub read_priv_key_str {
my ($class, $key_str) = @_;
$class->_load_key(1, $key_str);
}
1;
__END__
=head1 NAME
Crypt::OpenSSL::DSA - Digital Signature Algorithm using OpenSSL
=head1 SYNOPSIS
use Crypt::OpenSSL::DSA;
# generate keys and write out to PEM files
my $dsa = Crypt::OpenSSL::DSA->generate_parameters( 512 );
$dsa->generate_key;
$dsa->write_pub_key( $filename );
$dsa->write_priv_key( $filename );
# using keys from PEM files
my $dsa_priv = Crypt::OpenSSL::DSA->read_priv_key( $filename );
my $sig = $dsa_priv->sign($message);
my $dsa_pub = Crypt::OpenSSL::DSA->read_pub_key( $filename );
my $valid = $dsa_pub->verify($message, $sig);
# using keys from PEM strings
my $dsa_priv = Crypt::OpenSSL::DSA->read_priv_key_str( $key_string );
my $sig = $dsa_priv->sign($message);
my $dsa_pub = Crypt::OpenSSL::DSA->read_pub_key_str( $key_string );
my $valid = $dsa_pub->verify($message, $sig);
=head1 DESCRIPTION
Crypt::OpenSSL::DSA implements the DSA
(Digital Signature Algorithm) signature verification system.
It is a thin XS wrapper to the DSA functions contained in the
OpenSSL crypto library, located at http://www.openssl.org
=head1 CLASS METHODS
=over 4
=item $dsa = Crypt::OpenSSL::DSA->generate_parameters( $bits, $seed );
Returns a new DSA object and generates the p, q and g
parameters necessary to generate keys.
bits is the length of the prime to be generated; the DSS allows a maximum of 1024 bits.
=item $dsa = Crypt::OpenSSL::DSA->read_params( $filename );
Reads in a parameter PEM file and returns a new DSA object with the p, q and g
parameters necessary to generate keys.
=item $dsa = Crypt::OpenSSL::DSA->read_pub_key( $filename );
Reads in a public key PEM file and returns a new DSA object that can be used
to verify DSA signatures.
=item $dsa = Crypt::OpenSSL::DSA->read_priv_key( $filename );
Reads in a private key PEM file and returns a new DSA object that can be used
to sign messages.
=item $dsa = Crypt::OpenSSL::DSA->read_pub_key_str( $key_string );
Reads in a public key PEM string and returns a new DSA object that can be used
to verify DSA signatures.
The string should include the -----BEGIN...----- and -----END...----- lines.
=item $dsa = Crypt::OpenSSL::DSA->read_priv_key_str( $key_string );
Reads in a private key PEM string and returns a new DSA object that can be used
to sign messages.
The string should include the -----BEGIN...----- and -----END...----- lines.
=back
=head1 OBJECT METHODS
=over 4
=item $dsa->generate_key;
Generates private and public keys, assuming that $dsa is the return
value of generate_parameters.
=item $sig = $dsa->sign( $message );
Signs $message, returning the signature. Note that $meesage cannot exceed
20 characters in length.
$dsa is the signer's private key.
=item $sig_obj = $dsa->do_sign( $message );
Similar to C<sign>, but returns a L<Crypt::OpenSSL::DSA::Signature> object.
=item $valid = $dsa->verify( $message, $sig );
Verifies that the $sig signature for $message is valid.
$dsa is the signer's public key.
Note: it croaks if the underlying library call returns error (-1).
=item $valid = $dsa->do_verify( $message, $sig_obj );
Similar to C<verify>, but uses a L<Crypt::OpenSSL::DSA::Signature> object.
Note: it croaks if the underlying library call returns error (-1).
=item $dsa->write_params( $filename );
Writes the parameters into a PEM file.
=item $dsa->write_pub_key( $filename );
Writes the public key into a PEM file.
=item $dsa->write_priv_key( $filename );
Writes the private key into a PEM file.
=item $p = $dsa->get_p, $dsa->set_p($p)
Gets/sets the prime number in binary format.
=item $q = $dsa->get_q, $dsa->set_q($q)
Gets/sets the subprime number (q | p-1) in binary format.
=item $g = $dsa->get_g, $dsa->set_g($g)
Gets/sets the generator of subgroup in binary format.
=item $pub_key = $dsa->get_pub_key, $dsa->set_pub_key($pub_key)
Gets/sets the public key (y = g^x) in binary format.
=item $priv_key = $dsa->get_priv_key, $dsa->set_priv_key($priv_key)
Gets/sets the private key in binary format.
=back
=head1 NOTES
L<Crpyt::DSA> is a more mature Perl DSA module, but can be difficult to
install, because of the L<Math::Pari> requirement.
Comments, suggestions, and patches welcome.
=head1 AUTHOR
T.J. Mather, E<lt>tjmather@maxmind.comE<gt>
=head1 COPYRIGHT
Copyright (c) 2002 T.J. Mather. Crypt::OpenSSL::DSA is free software;
you may redistribute it and/or modify it under the same terms as Perl itself.
Paid support is available directly from the author of this package.
Please see L<http://www.maxmind.com/app/opensourceservices> for more details.
=head1 SEE ALSO
L<Crypt::OpenSSL::DSA::Signature>
L<Crypt::DSA>, L<Crypt::OpenSSL::RSA>
L<Net::DNS::SEC>
=cut