package Net::SSL::ExpireDate;

use strict;
use warnings;
use Carp;

our $VERSION = '1.10';

use base qw(Class::Accessor);
use Crypt::OpenSSL::X509 qw(FORMAT_ASN1);
use Date::Parse;
use DateTime;
use DateTime::Duration;
use Time::Duration::Parse;
use UNIVERSAL::require;

my $Socket = 'IO::Socket::INET6';
unless ($Socket->require) {
    $Socket = 'IO::Socket::INET';
    $Socket->require or die $@;
}

__PACKAGE__->mk_accessors(qw(type target));

my $SSL3_RT_CHANGE_CIPHER_SPEC = 20;
my $SSL3_RT_ALERT              = 21;
my $SSL3_RT_HANDSHAKE          = 22;
my $SSL3_RT_APPLICATION_DATA   = 23;

my $SSL3_MT_HELLO_REQUEST       =  0;
my $SSL3_MT_CLIENT_HELLO        =  1;
my $SSL3_MT_SERVER_HELLO        =  2;
my $SSL3_MT_CERTIFICATE         = 11;
my $SSL3_MT_SERVER_KEY_EXCHANGE = 12;
my $SSL3_MT_CERTIFICATE_REQUEST = 13;
my $SSL3_MT_SERVER_DONE         = 14;
my $SSL3_MT_CERTIFICATE_VERIFY  = 15;
my $SSL3_MT_CLIENT_KEY_EXCHANGE = 16;
my $SSL3_MT_FINISHED            = 20;

my $SSL3_AL_WARNING = 0x01;
my $SSL3_AL_FATAL   = 0x02;

my $SSL3_AD_CLOSE_NOTIFY            =  0;
my $SSL3_AD_UNEXPECTED_MESSAGE      = 10; # fatal
my $SSL3_AD_BAD_RECORD_MAC          = 20; # fatal
my $SSL3_AD_DECOMPRESSION_FAILURE   = 30; # fatal
my $SSL3_AD_HANDSHAKE_FAILURE       = 40; # fatal
my $SSL3_AD_NO_CERTIFICATE          = 41;
my $SSL3_AD_BAD_CERTIFICATE         = 42;
my $SSL3_AD_UNSUPPORTED_CERTIFICATE = 43;
my $SSL3_AD_CERTIFICATE_REVOKED     = 44;
my $SSL3_AD_CERTIFICATE_EXPIRED     = 45;
my $SSL3_AD_CERTIFICATE_UNKNOWN     = 46;
my $SSL3_AD_ILLEGAL_PARAMETER       = 47; # fatal

sub new {
    my ($class, %opt) = @_;

    my $self = bless {
        type        => undef,
        target      => undef,
        expire_date => undef,
        timeout     => undef,
       }, $class;

    if ( $opt{https} or $opt{ssl} ) {
        $self->{type}   = 'ssl';
        $self->{target} = $opt{https} || $opt{ssl};
    } elsif ($opt{file}) {
        $self->{type}   = 'file';
        $self->{target} = $opt{file};
        if (! -r $self->{target}) {
            croak "$self->{target}: $!";
        }
    } else {
        croak "missing option: neither ssl nor file";
    }
    if ($opt{timeout}) {
        $self->{timeout} = $opt{timeout};
    }

    return $self;
}

sub expire_date {
    my $self = shift;

    if (! $self->{expire_date}) {
        if ($self->{type} eq 'ssl') {
            my ($host, $port) = split /:/, $self->{target}, 2;
            $port ||= 443;
            ### $host
            ### $port
            my $cert = _peer_certificate($host, $port, $self->{timeout});
            my $x509 = Crypt::OpenSSL::X509->new_from_string($cert, FORMAT_ASN1);
            my $begin_date_str  = $x509->notBefore;
            my $expire_date_str = $x509->notAfter;

            $self->{expire_date} = DateTime->from_epoch(epoch => str2time($expire_date_str));
            $self->{begin_date}  = DateTime->from_epoch(epoch => str2time($begin_date_str));

        } elsif ($self->{type} eq 'file') {
            my $x509 = Crypt::OpenSSL::X509->new_from_file($self->{target});
            $self->{expire_date} = DateTime->from_epoch(epoch => str2time($x509->notAfter));
            $self->{begin_date}  = DateTime->from_epoch(epoch => str2time($x509->notBefore));
        } else {
            croak "unknown type: $self->{type}";
        }
    }

    return $self->{expire_date};
}

sub begin_date {
    my $self = shift;

    if (! $self->{begin_date}) {
        $self->expire_date;
    }

    return $self->{begin_date};
}

*not_after  = \&expire_date;
*not_before = \&begin_date;

sub is_expired {
    my ($self, $duration) = @_;
    $duration ||= DateTime::Duration->new();

    if (! $self->{begin_date}) {
        $self->expire_date;
    }

    if (! ref($duration)) { # if scalar
        $duration = DateTime::Duration->new(seconds => parse_duration($duration));
    }

    my $dx = DateTime->now()->add_duration( $duration );
    ### dx: $dx->iso8601

    return DateTime->compare($dx, $self->{expire_date}) >= 0 ? 1 : ();
}

sub _peer_certificate {
    my($host, $port, $timeout) = @_;

    my $cert;

    no warnings 'once';
    no strict 'refs'; ## no critic
    *{$Socket.'::write_atomically'} = sub {
        my($self, $data) = @_;

        my $length    = length $data;
        my $offset    = 0;
        my $read_byte = 0;

        while ($length > 0) {
            my $r = $self->syswrite($data, $length, $offset) || last;
            $offset    += $r;
            $length    -= $r;
            $read_byte += $r;
        }

        return $read_byte;
    };

    my $sock = {
        PeerAddr => $host,
        PeerPort => $port,
        Proto    => 'tcp',
        Timeout  => $timeout,
    };

    $sock = $Socket->new( %$sock ) or croak "cannot create socket: $!";

    _send_client_hello($sock);

    my $do_loop = 1;
    while ($do_loop) {
        my $record = _get_record($sock) or croak $!;
        croak "record type is not HANDSHAKE" if $record->{type} != $SSL3_RT_HANDSHAKE;

        while (my $handshake = _get_handshake($record)) {
            croak "too many loop" if $do_loop++ >= 10;
            if ($handshake->{type} == $SSL3_MT_HELLO_REQUEST) {
                ;
            } elsif ($handshake->{type} == $SSL3_MT_CERTIFICATE_REQUEST) {
                ;
            } elsif ($handshake->{type} == $SSL3_MT_SERVER_HELLO) {
                ;
            } elsif ($handshake->{type} == $SSL3_MT_CERTIFICATE) {
                my $data = $handshake->{data};
                my $len1 = $handshake->{length};
                my $len2 = (vec($data, 0, 8)<<16)+(vec($data, 1, 8)<<8)+vec($data, 2, 8);
                my $len3 = (vec($data, 3, 8)<<16)+(vec($data, 4, 8)<<8)+vec($data, 5, 8);
                croak "X509: length error" if $len1 != $len2 + 3;
                $cert = substr $data, 6; # DER format
            } elsif ($handshake->{type} == $SSL3_MT_SERVER_KEY_EXCHANGE) {
                ;
            } elsif ($handshake->{type} == $SSL3_MT_SERVER_DONE) {
                $do_loop = 0;
            } else {
                ;
            }
        }

    }

    _sendalert($sock, $SSL3_AL_FATAL, $SSL3_AD_HANDSHAKE_FAILURE) or croak $!;
    $sock->close;

    return $cert;
}

sub _send_client_hello {
    my($sock) = @_;

    my(@buf,$len);
    ## record
    push @buf, $SSL3_RT_HANDSHAKE;
    push @buf, 3, 0;
    push @buf, undef, undef;
    my $pos_record_len = $#buf-1;

    ## handshake
    push @buf, $SSL3_MT_CLIENT_HELLO;
    push @buf, undef, undef, undef;
    my $pos_handshake_len = $#buf-2;

    ## ClientHello
    # client_version
    push @buf, 3, 0;
    # random
    my $time = time;
    push @buf, (($time>>24) & 0xFF);
    push @buf, (($time>>16) & 0xFF);
    push @buf, (($time>> 8) & 0xFF);
    push @buf, (($time    ) & 0xFF);
    push @buf, ((0xFF) x 28);
    # session_id
    push @buf, 0;
    # cipher_suites
    $len = 27 * 2;
    push @buf, (($len >> 8) & 0xFF);
    push @buf, (($len     ) & 0xFF);
    for (my $i=1; $i<=27; $i++) {
        push @buf, (($i >> 8) & 0xFF);
        push @buf, (($i     ) & 0xFF);
    }
    # compression
    push @buf, 1;
    push @buf, 0;

    # record length
    $len = scalar(@buf) - $pos_record_len - 2;
    $buf[ $pos_record_len   ] = (($len >>  8) & 0xFF);
    $buf[ $pos_record_len+1 ] = (($len      ) & 0xFF);

    # handshake length
    $len = scalar(@buf) - $pos_handshake_len - 3;
    $buf[ $pos_handshake_len   ] = (($len >> 16) & 0xFF);
    $buf[ $pos_handshake_len+1 ] = (($len >>  8) & 0xFF);
    $buf[ $pos_handshake_len+2 ] = (($len      ) & 0xFF);

    my $data;
    $data .= pack('C', $_) for @buf;

    return $sock->write_atomically($data);
}

sub _get_record {
    my($sock) = @_;

    my $record = {
        type    => -1,
        version => -1,
        length  => -1,
        read    =>  0,
        data    => "",
    };

    $sock->read($record->{type}   , 1) or croak $!;
    $record->{type} = unpack 'C', $record->{type};

    $sock->read($record->{version}, 2) or croak $!;
    $record->{version} = unpack 'n', $record->{version};

    $sock->read($record->{length},  2) or croak $!;
    $record->{length}  = unpack 'n', $record->{length};

    $sock->read($record->{data},    $record->{length}) or croak $!;

    return $record;
}

sub _get_handshake {
    my($record) = @_;

    my $handshake = {
        type   => -1,
        length => -1,
        data   => "",
       };

    return if $record->{read} >= $record->{length};

    $handshake->{type}   = vec($record->{data}, $record->{read}++, 8);
    return if $record->{read} + 3 > $record->{length};

    $handshake->{length} =
         (vec($record->{data}, $record->{read}++, 8)<<16)
        +(vec($record->{data}, $record->{read}++, 8)<< 8)
        +(vec($record->{data}, $record->{read}++, 8)    );

    if ($handshake->{length} > 0) {
        $handshake->{data} = substr($record->{data}, $record->{read}, $handshake->{length});
        $record->{read} += $handshake->{length};
        return if $record->{read} > $record->{length};
    } else {
        $handshake->{data}= undef;
    }

    return $handshake;
}

sub _sendalert {
    my($sock, $level, $desc) = @_;

    my $data = "";

    $data .= pack('C', $SSL3_RT_ALERT);
    $data .= pack('C', 3);
    $data .= pack('C', 0);
    $data .= pack('C', 0);
    $data .= pack('C', 2);
    $data .= pack('C', $level);
    $data .= pack('C', $desc);

    return $sock->write_atomically($data);
}

1; # Magic true value required at end of module
__END__

=head1 NAME

Net::SSL::ExpireDate - obtain expiration date of certificate

=head1 SYNOPSIS

    use Net::SSL::ExpireDate;

    $ed = Net::SSL::ExpireDate->new( https => 'example.com' );
    $ed = Net::SSL::ExpireDate->new( https => 'example.com:10443' );
    $ed = Net::SSL::ExpireDate->new( ssl   => 'example.com:465' ); # smtps
    $ed = Net::SSL::ExpireDate->new( ssl   => 'example.com:995' ); # pop3s
    $ed = Net::SSL::ExpireDate->new( file  => '/etc/ssl/cert.pem' );

    if (defined $ed->expire_date) {
      # do something
      $expire_date = $ed->expire_date;         # return DateTime instance

      $expired = $ed->is_expired;              # examine already expired

      $expired = $ed->is_expired('2 months');  # will expire after 2 months
      $expired = $ed->is_expired(DateTime::Duration->new(months=>2));  # ditto
    }

=head1 DESCRIPTION

Net::SSL::ExpireDate get certificate from network (SSL) or local
file and obtain its expiration date.

=head1 METHODS

=head2 new

  $ed = Net::SSL::ExpireDate->new( %option )

This method constructs a new "Net::SSL::ExpireDate" instance and
returns it. %option is to specify certificate.

  KEY    VALUE
  ----------------------------
  ssl    "hostname[:port]"
  https  (same as above ssl)
  file   "path/to/certificate"

=head2 expire_date

  $expire_date = $ed->expire_date;

Return expiration date by "DateTime" instance.

=head2 begin_date

  $begin_date  = $ed->begin_date;

Return beginning date by "DateTime" instance.

=head2 not_after

Synonym for expire_date.

=head2 not_before

Synonym for begin_date.

=head2 is_expired

  $expired = $ed->is_expired;

Obtain already expired or not.

You can specify interval to obtain will expire on the future time.
Acceptable intervals are human readable string (parsed by
"Time::Duration::Parse") and "DateTime::Duration" instance.

  # will expire after 2 months
  $expired = $ed->is_expired('2 months');
  $expired = $ed->is_expired(DateTime::Duration->new(months=>2));

=head2 type

return type of examinee certificate. "ssl" or "file".

=head2 target

return hostname or path of examinee certificate.

=head1 BUGS AND LIMITATIONS

No bugs have been reported.

Please report any bugs or feature requests to
C<bug-net-ssl-expiredate@rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org>.

=head1 AUTHOR

HIROSE Masaaki E<lt>hirose31 _at_ gmail.comE<gt>

=head1 REPOSITORY

L<http://github.com/hirose31/net-ssl-expiredate>

  git clone git://github.com/hirose31/net-ssl-expiredate.git

patches and collaborators are welcome.

=head1 SEE ALSO

=head1 COPYRIGHT & LICENSE

Copyright HIROSE Masaaki

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

=cut

