NAME
    POE::Filter::SSL - The easiest and flexiblest way to SSL in POE!

VERSION
    Version 0.18

DESCRIPTION
    This module allows to secure connections of *POE::Wheel::ReadWrite* with
    OpenSSL by a *POE::Filter* object, and behaves (beside of SSLing) as
    *POE::Filter::Stream*.

    *POE::Filter::SSL* can be added, switched and removed during runtime,
    for example if you want to initiate SSL (see the *SSL on an established
    connection* example in *SYNOPSIS*) on an already established connection.
    You are able to combine *POE::Filter::SSL* with other filters, for
    example have a HTTPS server together with *POE::Filter::HTTPD* (see the
    *HTTPS-Server* example in *SYNOPSIS*).

    *POE::Filter::SSL* is based on *Net::SSLeay*, but got two XS functions
    which *Net::SSLeay* is missing.

    Features

          Full non-blocking processing

          No use of sockets at all

          Server and client mode

          Optional client certificate verification

          Allows to accept connections with invalid or missing client
          certificate and return custom error data

          CRL check of client certificates

          Retrieve client certificate details (subject name, issuer name,
          certificate serial)

    Upcoming Features

          Direct cipher encryption without SSL or TLS protocol, for example
          with static AES encryption

SYNOPSIS
    By default *POE::Filter::SSL* acts as a SSL server. To use it in client
    mode you just have to set the *client* option of *new()*.

    TCP-Client
        #!perl

        use warnings;
        use strict;

        use POE qw(Component::Client::TCP Filter::SSL);

        POE::Component::Client::TCP->new(
          RemoteAddress => "yahoo.com",
          RemotePort    => 443,
          Filter        => [ "POE::Filter::SSL", client => 1 ],
          Connected     => sub {
            $_[HEAP]{server}->put("HEAD /\r\n");
          },
          ServerInput   => sub {
            my $input = $_[ARG0];
            # The following line is needed to do the SSL handshake!
            return $_[HEAP]{server}->put() unless $input;
            print "from server: $input\n";
          },
        );

        POE::Kernel->run();
        exit;

    TCP-Server
        #!perl

        use warnings;
        use strict;

        use POE qw(Component::Server::TCP);

        POE::Component::Server::TCP->new(
          Port => 443,
          ClientFilter => [ "POE::Filter::SSL", crt => 'server.crt', key => 'server.key' ],
          ClientConnected => sub {
            print "got a connection from $_[HEAP]{remote_ip}\n";
            $_[HEAP]{client}->put("Smile from the server!");
          },
          ClientInput => sub {
            my $client_input = $_[ARG0];
            # The following line is needed to do the SSL handshake!
            return $_[HEAP]{client}->put() unless $client_input;
            $client_input =~ tr[a-zA-Z][n-za-mN-ZA-M];
            $_[HEAP]{client}->put($client_input);
          },
        );

        POE::Kernel->run;
        exit;

    HTTPS-Server
        #!perl
        use warnings;
        use strict;
        use POE qw(Component::Server::TCP Filter::SSL Filter::HTTPD);
        use HTTP::Response;
        POE::Component::Server::TCP->new(
          Alias        => "web_server",
          Port         => 443,
          ClientFilter => [ 'POE::Filter::SSL', crt => 'server.crt', key => 'server.key' ],
          ClientInput => sub {
            my ($kernel, $heap, $request) = @_[KERNEL, HEAP, ARG0];
            return unless (POE::Filter::SSL::doHandshake($heap->{client}, POE::Filter::HTTPD->new()));
            if ($request->isa("HTTP::Response")) {
              $heap->{client}->put($request);
              $kernel->yield("shutdown");
              return;
            }
            my $request_fields = '';
            $request->headers()->scan(
              sub {
                my ($header, $value) = @_;
                $request_fields .= "<tr><td>$header</td><td>$value</td></tr>";
              }
            );
            my $response = HTTP::Response->new(200);
            $response->push_header('Content-type', 'text/html');
            $response->content(
              "<html><head><title>Your Request</title></head>"
                . "<body>Details about your request:"
                . "<table border='1'>$request_fields</table>"
                . "</body></html>"
            );
            $heap->{client}->put($response);
            $kernel->yield("shutdown");
          }
        );
        $poe_kernel->run();



  SSL on an established connection
    Advanced Example
      This example is a IMAP-Relay which forwards the connections to a IMAP
      server by username. It allows the uncrypted transfer on port 143, with
      the option of SSL on the established connection (STARTTLS). On port
      993 it allows to do direct SSL.

      Tested with Thunderbird version 3.0.5.

        #!perl

        use warnings;
        use strict;

        use POE qw(Component::Server::TCP Component::Client::TCP Filter::SSL Filter::Stream);

        my $defaultImapServer = "not.existing.de";
        my $usernameToImapServer = {
           user1 => 'mailserver1.domain.de',
           user2 => 'mailserver2.domain.de',
           # ...
        };

        POE::Component::Server::TCP->new(
           Port => 143,
           ClientFilter => "POE::Filter::Stream",
           ClientDisconnected => \&disconnect,
           ClientConnected => \&connected,
           ClientInput => \&handleInput,
           InlineStates => {
              send_stuff => \&send_stuff,
              _child => \&child
           }
        );

        POE::Component::Server::TCP->new(
           Port => 993,
           ClientFilter => [ "POE::Filter::SSL", crt => 'server.crt', key => 'server.key' ],
           ClientConnected => \&connected,
           ClientDisconnected => \&disconnect,
           ClientInput => \&handleInput,
           InlineStates => {
              send_stuff => \&send_stuff,
              _child => \&child
           }
        );

        sub disconnect {
           my ($kernel, $session, $heap) = @_[KERNEL, SESSION, HEAP];
           logevent('server got disconnect', $session);
           $kernel->post($heap->{client_id} => "shutdown");
        }

        sub connected {
           my ($kernel, $session, $heap) = @_[KERNEL, SESSION, HEAP];
           logevent("got a connection from ".$heap->{remote_ip}, $session);
           $heap->{client}->put("* OK [CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE ACL ACL2=UNION STARTTLS] IMAP Relay v0.1 ready.\r\n");
        }

        sub send_stuff {
           my ($heap, $stuff, $session) = @_[HEAP, ARG0, SESSION];
           logevent("-> ".length($stuff)." Bytes", $session);
           (defined($heap->{client})) && (ref($heap->{client}) eq "POE::Wheel::ReadWrite") &&
           $heap->{client}->put($stuff);
        }

        sub child {
           my ($heap, $child_op, $child) = @_[HEAP, ARG0, ARG1];
           if ($child_op eq "create") {
              $heap->{client_id} = $child->ID;
           }
        }

        sub handleInput {
           my ($kernel, $session, $heap, $input) = @_[KERNEL, SESSION, HEAP, ARG0];
           return if ((ref($heap->{client}->get_output_filter()) eq "POE::Filter::SSL") && (!POE::Filter::SSL::doHandshake($heap->{client})));
           if($heap->{forwarding}) {
              return $kernel->yield("shutdown") unless (defined($heap->{client_id}));
              $kernel->post($heap->{client_id} => send_stuff => $input);
           } elsif ($input =~ /^(\d+)\s+STARTTLS[\r\n]+/i) {
              $_[HEAP]{client}->put($1." OK Begin SSL/TLS negotiation now.\r\n");
              logevent("SSLing now...", $session);
              $_[HEAP]{client}->set_filter(POE::Filter::SSL->new(crt => 'server.crt', key => 'server.key'));
           } elsif ($input =~ /^(\d+)\s+CAPABILITY[\r\n]+/i) {
              $_[HEAP]{client}->put("* CAPABILITY IMAP4rev1 UIDPLUS CHILDREN NAMESPACE THREAD=ORDEREDSUBJECT THREAD=REFERENCES SORT QUOTA IDLE ACL ACL2=UNION STARTTLS\r\n");
              $_[HEAP]{client}->put($1." OK CAPABILITY completed\r\n");
           } elsif ($input =~ /^(\d+)\s+login\s+\"(\S+)\"\s+\"(\S+)\"[\r\n]+/i) {
              my $username = $2;
              my $pass = $3;
              logevent("login of user ".$username, $session);
              spawn_client_side($username, $input);
              $heap->{forwarding}++;
           } else {
              logevent("unknown command before login, disconnecting.", $session);
              return $kernel->yield("shutdown");
           }
        }

        sub spawn_client_side {
          my $username = shift;
          POE::Component::Client::TCP->new(
            RemoteAddress => $usernameToImapServer->{$username} || $defaultImapServer,
            RemotePort    => 143,
            Filter => "POE::Filter::Stream",
            Started       => sub {
              $_[HEAP]->{server_id} = $_[SENDER]->ID;
              $_[HEAP]->{buf} = $_[ARG0];
              $_[HEAP]->{skip} = 0;
            },
            Connected => sub {
              my ($heap, $session) = @_[HEAP, SESSION];
              logevent('client connected', $session);
              $heap->{server}->put($heap->{buf});
              delete $heap->{buf};
            },
            ServerInput => sub {
              my ($kernel, $heap, $session, $input) = @_[KERNEL, HEAP, SESSION, ARG0];
              #logevent('client got input', $session, $input);
              $kernel->post($heap->{server_id} => send_stuff => $input) if ($heap->{skip}++);
            },
            Disconnected => sub {
              my ($kernel, $heap, $session) = @_[KERNEL, HEAP, SESSION];
              logevent('client disconnected', $session);
              $kernel->post($heap->{server_id} => 'shutdown');
            },
            InlineStates => {
              send_stuff => sub {
                my ($heap, $stuff, $session) = @_[HEAP, ARG0, SESSION];
                logevent("<- ".length($stuff)." Bytes", $session);
                (defined($heap->{server})) && (ref($heap->{server}) eq "POE::Wheel::ReadWrite") && 
                $heap->{server}->put($stuff);
              },
            },
            Args => [ shift ]
          );
        }

        sub logevent {
          my ($state, $session, $arg) = @_;
          my $id = $session->ID();
          print "session $id $state ";
          print ": $arg" if (defined $arg);
          print "\n";
        }

        POE::Kernel->run;

  Client certificate verification
    Advanced Example
      The following example implements a HTTPS server with client
      certificate verification, which shows details about the verified
      client certificate. It uses *doHandshake()* to add
      *POE::Filter::HTTPD* to process the cleartext data.

        #!perl

        use strict;
        use warnings;
        use Socket;
        use POE qw(
          Wheel::SocketFactory
          Wheel::ReadWrite
          Driver::SysRW
          Filter::SSL
          Filter::Stackable
          Filter::HTTPD
        );

        POE::Session->create(
          inline_states => {
            _start       => sub {
              my $heap = $_[HEAP];
              $heap->{listener} = POE::Wheel::SocketFactory->new(
                BindAddress  => '0.0.0.0',
                BindPort     => 443,
                Reuse        => 'yes',
                SuccessEvent => 'socket_birth',
                FailureEvent => '_stop',
              );
            },
            _stop => sub {
              delete $_[HEAP]->{listener};
            },
            socket_birth => sub {
              my ($socket) = $_[ARG0];
              POE::Session->create(
                inline_states => {
                  _start       => sub {
                    my ($heap, $kernel, $connected_socket, $address, $port) = @_[HEAP, KERNEL, ARG0, ARG1, ARG2];
                    $heap->{socket_wheel} = POE::Wheel::ReadWrite->new(
                      Handle     => $connected_socket,
                      Driver     => POE::Driver::SysRW->new(),
                      Filter     => POE::Filter::SSL->new(           ### HERE WE ARE!!!
                        crt    => 'server.crt',
                        key    => 'server.key',
                        cactr  => 'ca.crt',
                        cipher => 'AES256-SHA',
                        #cacrl  => 'ca.crl', # Uncomment this, if you have a CRL file.
                        debug  => 1,
                        clientcert => 1
                      ),
                      InputEvent => 'socket_input',
                      ErrorEvent => '_stop',
                    );
                    $heap->{sslfilter} = $heap->{socket_wheel}->get_input_filter();
                  },
                  socket_input => sub {
                    my ($kernel, $heap, $buf) = @_[KERNEL, HEAP, ARG0];
                    # The following line is needed to do the SSL handshake and add the Filter::HTTPD!
                    return unless POE::Filter::SSL::doHandshake($heap->{socket_wheel}, POE::Filter::HTTPD->new());
                    my ($certid) = ($heap->{sslfilter}->clientCertIds());
                    $certid = $certid ? $certid->[0]."<br>".$certid->[1]."<br>SERIAL=".$heap->{sslfilter}->hexdump($certid->[2]) : 'No client certificate';
                    my $content = '';
                    if ($heap->{sslfilter}->clientCertValid()) {
                      $content .= "Hello <font color=green>valid</font> client Certifcate:";
                    } else {
                      $content .= "None or <font color=red>invalid</font> client certificate:";
                    }
                    $content .= "<hr>".$certid."<hr>";
                    $content .= "Your URL was: ".$buf->uri."<hr>"
                      if (ref($buf) eq "HTTP::Request");
                    $content .= localtime(time());
                    my $response = HTTP::Response->new(200);
                    $response->push_header('Content-type', 'text/html');
                    $response->content($content);
                    $heap->{socket_wheel}->put($response);
                    $kernel->delay(_stop => 1);
                  },
                  _stop => sub {
                    delete $_[HEAP]->{socket_wheel};
                  }
                },
                args => [$socket],
              );
            }
          }
        );

        $poe_kernel->run();

FUNCTIONS
    new(option = value, option => value, option...)>
        Returns a new *POE::Filter::SSL* object. It accepts the following
        options:

        debug
          Shows debug messages of *clientCertNotOnCRL()*.

        client
          By default *POE::Filter::SSL* acts as a SSL server. To use it in
          client mode, you have to set this option.

        crt
          The certificate file (.crt) for the server, only needed in server
          mode.

        key
          The key file (.key) of the certificate for the server, only needed
          in server mode.

        clientcert
          The server requests the client for a client certificat during ssl
          handshake, only useful in server mode.

          WARNING: If the client provides an untrusted or no client
          certficate, the connection is not failing. You have to ask
          *clientCertValid()* if the certicate is valid!

        cacrt
          The ca certificate file (ca.crt), which is used to verificate the
          client certificates against a CA.

        cacrl
          Configures a CRL (ca.crl) against the client certificate is
          verified by *clientCertValid()*.

        cipher
          Specify which ciphers are allowed for the synchronous encrypted
          transfer of the data over the ssl connection.

          Example:

            cipher => 'AES256-SHA'

        blockbadclientcert
          Let OpenSSL deny the connection if there is no or an invalid
          client certificate.

          WARNING: If the client is listed in the CRL file, the connection
          will be established! You have to ask *clientCertValid()* if you
          have the *crl* option set on *new()*, otherwise to ask
          *clientCertNotOnCRL()* if the certificate is listed on your CRL
          file!

    handshakeDone(options)
        Returns *true* if the handshake is done and all data for hanshake
        has been written out. It accepts the following options:

        ignorebuf
          Returns *true* if OpenSSL has established the connection,
          regardless if all data has been written out. This is needed if you
          want to exchange the Filter of *POE::Wheel::ReadWrite* before the
          first data comes in. This option is currently only used by
          *doHandshake()* to be able to add new filters before first
          cleartext data to be processed gets in.

    clientCertNotOnCRL($file)
        Verifies if the serial of the client certificate is not contained in
        the CRL $file. No file caching is done, each call opens the file
        again.

        WARNING: If your CRL file is missing, can not be opened is empty or
        has no blocked certificate at all in it, then every call will get
        blocked!

    clientCertIds()
        Returns an array of every certificate found by OpenSSL. Each element
        is again a array. The first element is the value of
        *X509_get_subject_name*, second is the value of
        *X509_get_issuer_name* and third element is the serial of the
        certificate in binary form. You have to use *split()* and *ord()*,
        or the *hexdump()* function, to convert it to a readable form.

        Example:

          my ($certid) = ($heap->{sslfilter}->clientCertIds());
          $certid = $certid ? $certid->[0]."<br>".$certid->[1]."<br>SERIAL=".$heap->{sslfilter}->hexdump($certid->[2]) : 'No client certificate';

    clientCertValid()
        Returns *true* if there is a client certificate that is valid. It
        also tests against the CRL, if you have the *cacrl* option set on
        *new()*.

    doHandshake($readWrite, $filter, $filter, ...)
        Allows to add filters after the ssl handshake. It has to be called
        in the input handler, and needs the passing of the
        *POE::Wheel::ReadWhile* object. If it returns false, you have to
        return from the input handler.

        See the *HTTPS-Server*, *SSL on an established connection* and
        *Client certificate verification* examples in *SYNOPSIS*

    clientCertExists()
        Returns *true* if there is a client certificate, that might be
        untrusted.

        WARNING: If the client provides an untrusted client certficate a
        client certicate that is listed in CRL, this function returns
        *true*. You have to ask *clientCertValid()* if the certicate is
        valid!

    hexdump($string)
        Returns string data in hex format.

        Example:

          perl -e 'use POE::Filter::SSL; print POE::Filter::SSL->hexdump("test")."\n";'
          74:65:73:74

  Internal functions and POE::Filter handler
    VERIFY()
    X509_get_serialNumber()
    clone()
    doSSL()
    get()
    get_one()
    get_one_start()
    get_pending()
    writeToSSLBIO()
    writeToSSL()
    put()
    verify_serial_against_crl_file()

AUTHOR
    Markus Mueller, "<privi at cpan.org>"

BUGS
    Please report any bugs or feature requests to "bug-poe-filter-ssl at
    rt.cpan.org", or through the web interface at
    <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=POE-Filter-SSL>. I will
    be notified, and then you'll automatically be notified of progress on
    your bug as I make changes.

SUPPORT
    You can find documentation for this module with the perldoc command.

        perldoc POE::Filter::SSL

    You can also look for information at:

    *   RT: CPAN's request tracker

        <http://rt.cpan.org/NoAuth/Bugs.html?Dist=POE-Filter-SSL>

    *   AnnoCPAN: Annotated CPAN documentation

        <http://annocpan.org/dist/POE-Filter-SSL>

    *   CPAN Ratings

        <http://cpanratings.perl.org/d/POE-Filter-SSL>

    *   Search CPAN

        <http://search.cpan.org/dist/POE-Filter-SSL>

Commercial support
    Commercial support can be gained at <sslsupport at priv.de>

COPYRIGHT & LICENSE
    Copyright 2010 Markus Mueller, all rights reserved.

    This program is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.