util/perl/TLSProxy/ServerHello.pm

   1 # Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
   2 #
   3 # Licensed under the OpenSSL license (the "License").  You may not use
   4 # this file except in compliance with the License.  You can obtain a copy
   5 # in the file LICENSE in the source distribution or at
   6 # https://www.openssl.org/source/license.html
   7
   8 use strict;
   9
  10 package TLSProxy::ServerHello;
  11
  12 use vars '@ISA';
  13 push @ISA, 'TLSProxy::Message';
  14
  15 sub new
  16 {
  17     my $class = shift;
  18     my ($server,
  19         $data,
  20         $records,
  21         $startoffset,
  22         $message_frag_lens) = @_;
  23
  24     my $self = $class->SUPER::new(
  25         $server,
  26         TLSProxy::Message::MT_SERVER_HELLO,
  27         $data,
  28         $records,
  29         $startoffset,
  30         $message_frag_lens);
  31
  32     $self->{server_version} = 0;
  33     $self->{random} = [];
  34     $self->{session_id_len} = 0;
  35     $self->{session} = "";
  36     $self->{ciphersuite} = 0;
  37     $self->{comp_meth} = 0;
  38     $self->{extension_data} = "";
  39
  40     return $self;
  41 }
  42
  43 sub parse
  44 {
  45     my $self = shift;
  46     my $ptr = 2;
  47     my ($server_version) = unpack('n', $self->data);
  48
  49     my $random = substr($self->data, $ptr, 32);
  50     $ptr += 32;
  51     my $session_id_len = 0;
  52     my $session = "";
  53     $session_id_len = unpack('C', substr($self->data, $ptr));
  54     $ptr++;
  55     $session = substr($self->data, $ptr, $session_id_len);
  56     $ptr += $session_id_len;
  57
  58     my $ciphersuite = unpack('n', substr($self->data, $ptr));
  59     $ptr += 2;
  60     my $comp_meth = 0;
  61     $comp_meth = unpack('C', substr($self->data, $ptr));
  62     $ptr++;
  63
  64     my $extensions_len = unpack('n', substr($self->data, $ptr));
  65     if (!defined $extensions_len) {
  66         $extensions_len = 0;
  67     } else {
  68         $ptr += 2;
  69     }
  70     #For now we just deal with this as a block of data. In the future we will
  71     #want to parse this
  72     my $extension_data;
  73     if ($extensions_len != 0) {
  74         $extension_data = substr($self->data, $ptr);
  75
  76         if (length($extension_data) != $extensions_len) {
  77             die "Invalid extension length\n";
  78         }
  79     } else {
  80         if (length($self->data) != $ptr) {
  81             die "Invalid extension length\n";
  82         }
  83         $extension_data = "";
  84     }
  85     my %extensions = ();
  86     while (length($extension_data) >= 4) {
  87         my ($type, $size) = unpack("nn", $extension_data);
  88         my $extdata = substr($extension_data, 4, $size);
  89         $extension_data = substr($extension_data, 4 + $size);
  90         $extensions{$type} = $extdata;
  91         if ($type == TLSProxy::Message::EXT_SUPPORTED_VERSIONS) {
  92             $server_version = unpack('n', $extdata);
  93         }
  94     }
  95
  96     # TODO(TLS1.3): Replace this reference to draft version before release
  97     if ($server_version == TLSProxy::Record::VERS_TLS_1_3_DRAFT) {
  98         $server_version = TLSProxy::Record::VERS_TLS_1_3;
  99         TLSProxy::Proxy->is_tls13(1);
 100     }
 101
 102     $self->server_version($server_version);
 103     $self->random($random);
 104     $self->session_id_len($session_id_len);
 105     $self->session($session);
 106     $self->ciphersuite($ciphersuite);
 107     TLSProxy::Proxy->ciphersuite($ciphersuite);
 108     $self->comp_meth($comp_meth);
 109     $self->extension_data(\%extensions);
 110
 111     $self->process_data();
 112
 113     if (TLSProxy::Proxy->is_tls13()) {
 114         TLSProxy::Record->server_encrypting(1);
 115         TLSProxy::Record->client_encrypting(1);
 116     }
 117
 118     print "    Server Version:".$server_version."\n";
 119     print "    Session ID Len:".$session_id_len."\n";
 120     print "    Ciphersuite:".$ciphersuite."\n";
 121     print "    Compression Method:".$comp_meth."\n";
 122     print "    Extensions Len:".$extensions_len."\n";
 123 }
 124
 125 #Perform any actions necessary based on the data we've seen
 126 sub process_data
 127 {
 128     my $self = shift;
 129
 130     TLSProxy::Message->ciphersuite($self->ciphersuite);
 131 }
 132
 133 #Reconstruct the on-the-wire message data following changes
 134 sub set_message_contents
 135 {
 136     my $self = shift;
 137     my $data;
 138     my $extensions = "";
 139
 140     $data = pack('n', $self->server_version);
 141     $data .= $self->random;
 142     $data .= pack('C', $self->session_id_len);
 143     $data .= $self->session;
 144     $data .= pack('n', $self->ciphersuite);
 145     $data .= pack('C', $self->comp_meth);
 146
 147     foreach my $key (keys %{$self->extension_data}) {
 148         my $extdata = ${$self->extension_data}{$key};
 149         $extensions .= pack("n", $key);
 150         $extensions .= pack("n", length($extdata));
 151         $extensions .= $extdata;
 152         if ($key == TLSProxy::Message::EXT_DUPLICATE_EXTENSION) {
 153           $extensions .= pack("n", $key);
 154           $extensions .= pack("n", length($extdata));
 155           $extensions .= $extdata;
 156         }
 157     }
 158
 159     $data .= pack('n', length($extensions));
 160     $data .= $extensions;
 161     $self->data($data);
 162 }
 163
 164 #Read/write accessors
 165 sub server_version
 166 {
 167     my $self = shift;
 168     if (@_) {
 169       $self->{server_version} = shift;
 170     }
 171     return $self->{server_version};
 172 }
 173 sub random
 174 {
 175     my $self = shift;
 176     if (@_) {
 177       $self->{random} = shift;
 178     }
 179     return $self->{random};
 180 }
 181 sub session_id_len
 182 {
 183     my $self = shift;
 184     if (@_) {
 185       $self->{session_id_len} = shift;
 186     }
 187     return $self->{session_id_len};
 188 }
 189 sub session
 190 {
 191     my $self = shift;
 192     if (@_) {
 193       $self->{session} = shift;
 194     }
 195     return $self->{session};
 196 }
 197 sub ciphersuite
 198 {
 199     my $self = shift;
 200     if (@_) {
 201       $self->{ciphersuite} = shift;
 202     }
 203     return $self->{ciphersuite};
 204 }
 205 sub comp_meth
 206 {
 207     my $self = shift;
 208     if (@_) {
 209       $self->{comp_meth} = shift;
 210     }
 211     return $self->{comp_meth};
 212 }
 213 sub extension_data
 214 {
 215     my $self = shift;
 216     if (@_) {
 217       $self->{extension_data} = shift;
 218     }
 219     return $self->{extension_data};
 220 }
 221 sub set_extension
 222 {
 223     my ($self, $ext_type, $ext_data) = @_;
 224     $self->{extension_data}{$ext_type} = $ext_data;
 225 }
 226 sub delete_extension
 227 {
 228     my ($self, $ext_type) = @_;
 229     delete $self->{extension_data}{$ext_type};
 230 }
 231 1;