#################### main pod documentation begin ###################

=head1 NAME

  Zymonic::Decryptor - Zymonic Decryptor base module.

=head1 SYNOPSIS

 TODO

=head1 DESCRIPTION

 TODO

=head1 USAGE

 TODO

=head1 BUGS

None we're aware of...

=head1 SUPPORT

As in the license, Zymonic is provided without warranty or support
unless purchased separately, however... If you email 
zymonic-support@zednax.com your issue will   be noted and may 
receive a response.

For security issues, please contact zymonic-security@zednax.com and
someone will respond within 8 working hours.


=head1 AUTHOR

    Alex Masidlover et al.
    CPAN ID: MODAUTHOR
    Zednax Limited
    alex.masidlover@zednax.com
    http://www.zednax.com

=head1 COPYRIGHT

This program is free software licensed under the...

    Alfresco Public License 1.0

The full text of the license can be found in the
LICENSE file included with this module.

Other licenses may be acceptable if including
parts of Zymonic in larger projects, please
contact Zednax for details. 

=head1 SEE ALSO

perl(1).

=cut

#################### main pod documentation end ###################

package Zymonic::Decryptor;

use strict;
use warnings;

BEGIN
{
    use Exporter ();
    use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
    $VERSION = '0.01';
    @ISA     = qw(Exporter);

    #Give a hoot don't pollute, do not export more than needed by default
    @EXPORT      = qw();
    @EXPORT_OK   = qw();
    %EXPORT_TAGS = ();
}

use MIME::Base64;
use Storable qw(nfreeze thaw);

#################### subroutine header begin ####################

=head2 new

 Usage     : not to be called directly. 
 Purpose   : This is the constructor for the Zymonic Decryptor.
 Returns   : a Zymonic::Decryptor object
 Argument  : nothing
 Throws    : nothing
 Comment   : 

See Also   : Zymonic::Decryptor::init

=cut

#################### subroutine header end ####################

sub new
{
    my $invocant = shift;
    my $class    = ref($invocant) || $invocant;
    my $self     = {@_};                          # Remaining args become attributes

    $self->{zz_decryptor_fields} = ' hostname, port, d_posix_process_id, has_key, in_use, id, reenc_pid, nofork ';

    bless $self, $class;

    $self->init;

    return $self;

}

#################### subroutine header begin ####################

=head2 init

 Usage     :  $zd->init
 Purpose   : This is called by the constructor for the Zymonic 
 Decryptor to perform initialisation tasks.
 Returns   : nothing
 Argument  : nothing
 Throws    : Zymonic::Exception::Decryptor::MissingConfig
 Comment   : 

See Also   : Zymonic::Decryptor::new

=cut

#################### subroutine header end ####################

sub init
{
    my $self = shift;

    # Exception if no Config
    Zymonic::Exception::Decryptor::MissingConfig->throw() unless $self->{config};

}

#################### subroutine header begin ####################

=head2 load_key_file

 Usage     :  $zd->load_key_file($keytype, $keydir)
 Purpose   : This loads a key file.
 Returns   : the key
 Argument  : the keytype (public or private)
 Throws    : Zymonic::Exception::Decryptor::MissingKeyFile
 Comment   : 

See Also   : Zymonic::Decryptor::new

=cut

#################### subroutine header end ####################

sub load_key_file
{
    my $self       = shift;
    my $keytype    = shift || '';
    my $keydir     = shift || '';
    my $keyversion = shift || '';

    my $keyfile = '';
    my $base64  = 0;
    if ( -f $keydir . '/' . $keytype . 'key' . $keyversion . '.txt' )
    {
        $keyfile = $keydir . '/' . $keytype . 'key' . $keyversion . '.txt';
    }
    elsif ( -f $keydir . '/' . $keytype . 'key' . $keyversion . '.bin' )
    {
        $keyfile = $keydir . '/' . $keytype . 'key' . $keyversion . '.bin';
    }
    elsif ( -f $keydir . '/' . $keytype . 'key' . $keyversion . '.base64' )
    {
        $keyfile = $keydir . '/' . $keytype . 'key' . $keyversion . '.base64';
        $base64  = 1;
    }
    else
    {
        Zymonic::Exception::Decryptor::MissingKeyFile->throw( keytype => $keytype );
    }

    open( FLE, '<', $keyfile );
    my $ret = '';
    while (<FLE>)
    {
        $ret .= ( $base64 ? decode_base64($_) : $_ );
    }
    close(FLE);

    return $ret;

}

#################### subroutine header begin ####################

=head2 freeze_and_pack

 Usage     :  $zd->freeze_and_pack($message)
 Purpose   : This uses pack and freeze to create a string suitable 
 for sending over an SSL socket.
 Returns   : a string suitable for sending over an SSL socket
 Argument  : a hashref
 Throws    : nothing
 Comment   : 

See Also   : Zymonic::Decryptor::new

=cut

#################### subroutine header end ####################

sub freeze_and_pack
{
    my $self    = shift;
    my $message = shift;

    my $packet = nfreeze($message);
    $packet = pack( "N/a*", $packet );
    return $packet;

}

#################### subroutine header begin ####################

=head2 unpack_and_thaw

 Usage     :  $zd->unpack_and_thaw($socket)
 Purpose   : This uses unpack and thaw to receive data from an
 SSL socket.
 Returns   : a hashref
 Argument  : a socket
 Throws    : Zymonic::Exception::Decryptor::ReceiveFailed
 Comment   : 

See Also   : Zymonic::Decryptor::new

=cut

#################### subroutine header end ####################

sub unpack_and_thaw
{
    my $self   = shift;
    my $handle = shift;

    Zymonic::Exception::Decryptor::ReceiveFailed->throw() unless 4 == read( $handle, my $buffer, 4 );
    my $length = unpack( "N", $buffer );
    Zymonic::Exception::Decryptor::ReceiveFailed->throw() unless $length == read( $handle, $buffer, $length );
    return thaw($buffer);
}

1;