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# Copyright 2016-2018 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::ServerHello;
use vars '@ISA';
push @ISA, 'TLSProxy::Message';
my $hrrrandom = pack("C*", 0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11, 0xBE,
0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91, 0xC2, 0xA2,
0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E, 0x07, 0x9E, 0x09,
0xE2, 0xC8, 0xA8, 0x33, 0x9C);
sub new
{
my $class = shift;
my ($server,
$data,
$records,
$startoffset,
$message_frag_lens) = @_;
my $self = $class->SUPER::new(
$server,
TLSProxy::Message::MT_SERVER_HELLO,
$data,
$records,
$startoffset,
$message_frag_lens);
$self->{server_version} = 0;
$self->{random} = [];
$self->{session_id_len} = 0;
$self->{session} = "";
$self->{ciphersuite} = 0;
$self->{comp_meth} = 0;
$self->{extension_data} = "";
return $self;
}
sub parse
{
my $self = shift;
my $ptr = 2;
my ($server_version) = unpack('n', $self->data);
my $neg_version = $server_version;
my $random = substr($self->data, $ptr, 32);
$ptr += 32;
my $session_id_len = 0;
my $session = "";
$session_id_len = unpack('C', substr($self->data, $ptr));
$ptr++;
$session = substr($self->data, $ptr, $session_id_len);
$ptr += $session_id_len;
my $ciphersuite = unpack('n', substr($self->data, $ptr));
$ptr += 2;
my $comp_meth = 0;
$comp_meth = unpack('C', substr($self->data, $ptr));
$ptr++;
my $extensions_len = unpack('n', substr($self->data, $ptr));
if (!defined $extensions_len) {
$extensions_len = 0;
} else {
$ptr += 2;
}
#For now we just deal with this as a block of data. In the future we will
#want to parse this
my $extension_data;
if ($extensions_len != 0) {
$extension_data = substr($self->data, $ptr);
if (length($extension_data) != $extensions_len) {
die "Invalid extension length\n";
}
} else {
if (length($self->data) != $ptr) {
die "Invalid extension length\n";
}
$extension_data = "";
}
my %extensions = ();
while (length($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} = $extdata;
if ($type == TLSProxy::Message::EXT_SUPPORTED_VERSIONS) {
$neg_version = unpack('n', $extdata);
}
}
if ($random eq $hrrrandom) {
TLSProxy::Proxy->is_tls13(1);
} elsif ($neg_version == TLSProxy::Record::VERS_TLS_1_3) {
TLSProxy::Proxy->is_tls13(1);
TLSProxy::Record->server_encrypting(1);
TLSProxy::Record->client_encrypting(1);
}
$self->server_version($server_version);
$self->random($random);
$self->session_id_len($session_id_len);
$self->session($session);
$self->ciphersuite($ciphersuite);
TLSProxy::Proxy->ciphersuite($ciphersuite);
$self->comp_meth($comp_meth);
$self->extension_data(\%extensions);
$self->process_data();
print " Server Version:".$server_version."\n";
print " Session ID Len:".$session_id_len."\n";
print " Ciphersuite:".$ciphersuite."\n";
print " Compression Method:".$comp_meth."\n";
print " Extensions Len:".$extensions_len."\n";
}
#Perform any actions necessary based on the data we've seen
sub process_data
{
my $self = shift;
TLSProxy::Message->ciphersuite($self->ciphersuite);
}
#Reconstruct the on-the-wire message data following changes
sub set_message_contents
{
my $self = shift;
my $data;
my $extensions = "";
$data = pack('n', $self->server_version);
$data .= $self->random;
$data .= pack('C', $self->session_id_len);
$data .= $self->session;
$data .= pack('n', $self->ciphersuite);
$data .= pack('C', $self->comp_meth);
foreach my $key (keys %{$self->extension_data}) {
my $extdata = ${$self->extension_data}{$key};
$extensions .= pack("n", $key);
$extensions .= pack("n", length($extdata));
$extensions .= $extdata;
if ($key == TLSProxy::Message::EXT_DUPLICATE_EXTENSION) {
$extensions .= pack("n", $key);
$extensions .= pack("n", length($extdata));
$extensions .= $extdata;
}
}
$data .= pack('n', length($extensions));
$data .= $extensions;
$self->data($data);
}
#Read/write accessors
sub server_version
{
my $self = shift;
if (@_) {
$self->{server_version} = shift;
}
return $self->{server_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
{
my $self = shift;
if (@_) {
$self->{ciphersuite} = shift;
}
return $self->{ciphersuite};
}
sub comp_meth
{
my $self = shift;
if (@_) {
$self->{comp_meth} = shift;
}
return $self->{comp_meth};
}
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;
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