# Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.

#

# Licensed under the OpenSSL license (the "License").  You may not use

# this file except in compliance with the License.  You can obtain a copy

# in the file LICENSE in the source distribution or at

# https://www.openssl.org/source/license.html

use strict;

package TLSProxy::ClientHello;

use vars '@ISA';

push @ISA, 'TLSProxy::Message';

sub new

{

    my $class = shift;

    my ($server,

        $data,

        $records,

        $startoffset,

        $message_frag_lens) = @_;

    my $self = $class->SUPER::new(

        $server,

        1,

        $data,

        $records,

        $startoffset,

        $message_frag_lens);

    $self->{client_version} = 0;

    $self->{random} = [];

    $self->{session_id_len} = 0;

    $self->{session} = "";

    $self->{ciphersuite_len} = 0;

    $self->{ciphersuites} = [];

    $self->{comp_meth_len} = 0;

    $self->{comp_meths} = [];

    $self->{extensions_len} = 0;

    $self->{extension_data} = "";

    return $self;

}

sub parse

{

    my $self = shift;

    my $ptr = 2;

    my ($client_version) = unpack('n', $self->data);

    my $random = substr($self->data, $ptr, 32);

    $ptr += 32;

    my $session_id_len = unpack('C', substr($self->data, $ptr));

    $ptr++;

    my $session = substr($self->data, $ptr, $session_id_len);

    $ptr += $session_id_len;

    my $ciphersuite_len = unpack('n', substr($self->data, $ptr));

    $ptr += 2;

    my @ciphersuites = unpack('n*', substr($self->data, $ptr,

                                           $ciphersuite_len));

    $ptr += $ciphersuite_len;

    my $comp_meth_len = unpack('C', substr($self->data, $ptr));

    $ptr++;

    my @comp_meths = unpack('C*', substr($self->data, $ptr, $comp_meth_len));

    $ptr += $comp_meth_len;

    my $extensions_len = unpack('n', substr($self->data, $ptr));

    $ptr += 2;

    #For now we just deal with this as a block of data. In the future we will

    #want to parse this

    my $extension_data = substr($self->data, $ptr);

    if (length($extension_data) != $extensions_len) {

        die "Invalid extension length\n";

    }

    my %extensions = ();

    while (length($extension_data) >= 4) {

        my ($type, $size) = unpack("nn", $extension_data);

        my $extdata = substr($extension_data, 4, $size);

        $extension_data = substr($extension_data, 4 + $size);

        $extensions{$type} = $extdata;

    }

    $self->client_version($client_version);

    $self->random($random);

    $self->session_id_len($session_id_len);

    $self->session($session);

    $self->ciphersuite_len($ciphersuite_len);

    $self->ciphersuites(\@ciphersuites);

    $self->comp_meth_len($comp_meth_len);

    $self->comp_meths(\@comp_meths);

    $self->extensions_len($extensions_len);

    $self->extension_data(\%extensions);

    $self->process_extensions();

    print "    Client Version:".$client_version."\n";

    print "    Session ID Len:".$session_id_len."\n";

    print "    Ciphersuite len:".$ciphersuite_len."\n";

    print "    Compression Method Len:".$comp_meth_len."\n";

    print "    Extensions Len:".$extensions_len."\n";

}

#Perform any actions necessary based on the extensions we've seen

sub process_extensions

{

    my $self = shift;

    my %extensions = %{$self->extension_data};

    #Clear any state from a previous run

    TLSProxy::Record->etm(0);

    if (exists $extensions{TLSProxy::Message::EXT_ENCRYPT_THEN_MAC}) {

        TLSProxy::Record->etm(1);

    }

}

sub extension_contents

{

    my $self = shift;

    my $key = shift;

    my $extension = "";

    my $extdata = ${$self->extension_data}{$key};

    $extension .= pack("n", $key);

    $extension .= pack("n", length($extdata));

    $extension .= $extdata;

    return $extension;

}

#Reconstruct the on-the-wire message data following changes

sub set_message_contents

{

    my $self = shift;

    my $data;

    my $extensions = "";

    $data = pack('n', $self->client_version);

    $data .= $self->random;

    $data .= pack('C', $self->session_id_len);

    $data .= $self->session;

    $data .= pack('n', $self->ciphersuite_len);

    $data .= pack("n*", @{$self->ciphersuites});

    $data .= pack('C', $self->comp_meth_len);

    $data .= pack("C*", @{$self->comp_meths});

    foreach my $key (keys %{$self->extension_data}) {

        next if ($key == TLSProxy::Message::EXT_PSK);

        $extensions .= $self->extension_contents($key);

        #Add extension twice if we are duplicating that extension

        $extensions .= $self->extension_contents($key) if ($key == $self->dupext);

    }

    #PSK extension always goes last...

    if (defined ${$self->extension_data}{TLSProxy::Message::EXT_PSK}) {

        $extensions .= $self->extension_contents(TLSProxy::Message::EXT_PSK);

    }

    #unless we have EXT_FORCE_LAST

    if (defined ${$self->extension_data}{TLSProxy::Message::EXT_FORCE_LAST}) {

        $extensions .= $self->extension_contents(TLSProxy::Message::EXT_FORCE_LAST);

    }

    $data .= pack('n', length($extensions));

    $data .= $extensions;

    $self->data($data);

}

#Read/write accessors

sub client_version

{

    my $self = shift;

    if (@_) {

      $self->{client_version} = shift;

    }

    return $self->{client_version};

}

sub random

{

    my $self = shift;

    if (@_) {

      $self->{random} = shift;

    }

    return $self->{random};

}

sub session_id_len

{

    my $self = shift;

    if (@_) {

      $self->{session_id_len} = shift;

    }

    return $self->{session_id_len};

}

sub session

{

    my $self = shift;

    if (@_) {

      $self->{session} = shift;

    }

    return $self->{session};

}

sub ciphersuite_len

{

    my $self = shift;

    if (@_) {

      $self->{ciphersuite_len} = shift;

    }

    return $self->{ciphersuite_len};

}

sub ciphersuites

{

    my $self = shift;

    if (@_) {

      $self->{ciphersuites} = shift;

    }

    return $self->{ciphersuites};

}

sub comp_meth_len

{

    my $self = shift;

    if (@_) {

      $self->{comp_meth_len} = shift;

    }

    return $self->{comp_meth_len};

}

sub comp_meths

{

    my $self = shift;

    if (@_) {

      $self->{comp_meths} = shift;

    }

    return $self->{comp_meths};

}

sub extensions_len

{

    my $self = shift;

    if (@_) {

      $self->{extensions_len} = shift;

    }

    return $self->{extensions_len};

}

sub extension_data

{

    my $self = shift;

    if (@_) {

      $self->{extension_data} = shift;

    }

    return $self->{extension_data};

}

sub set_extension

{

    my ($self, $ext_type, $ext_data) = @_;

    $self->{extension_data}{$ext_type} = $ext_data;

}

sub delete_extension

{

    my ($self, $ext_type) = @_;

    delete $self->{extension_data}{$ext_type};

}

1;