1# Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
2#
3# Licensed under the Apache License 2.0 (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
8use strict;
9
10package TLSProxy::ServerHello;
11
12use vars '@ISA';
13push @ISA, 'TLSProxy::Message';
14
15my $hrrrandom = pack("C*", 0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11, 0xBE,
16                           0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91, 0xC2, 0xA2,
17                           0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E, 0x07, 0x9E, 0x09,
18                           0xE2, 0xC8, 0xA8, 0x33, 0x9C);
19
20sub new
21{
22    my $class = shift;
23    my ($server,
24        $data,
25        $records,
26        $startoffset,
27        $message_frag_lens) = @_;
28
29    my $self = $class->SUPER::new(
30        $server,
31        TLSProxy::Message::MT_SERVER_HELLO,
32        $data,
33        $records,
34        $startoffset,
35        $message_frag_lens);
36
37    $self->{server_version} = 0;
38    $self->{random} = [];
39    $self->{session_id_len} = 0;
40    $self->{session} = "";
41    $self->{ciphersuite} = 0;
42    $self->{comp_meth} = 0;
43    $self->{extension_data} = "";
44
45    return $self;
46}
47
48sub parse
49{
50    my $self = shift;
51    my $ptr = 2;
52    my ($server_version) = unpack('n', $self->data);
53    my $neg_version = $server_version;
54
55    my $random = substr($self->data, $ptr, 32);
56    $ptr += 32;
57    my $session_id_len = 0;
58    my $session = "";
59    $session_id_len = unpack('C', substr($self->data, $ptr));
60    $ptr++;
61    $session = substr($self->data, $ptr, $session_id_len);
62    $ptr += $session_id_len;
63
64    my $ciphersuite = unpack('n', substr($self->data, $ptr));
65    $ptr += 2;
66    my $comp_meth = 0;
67    $comp_meth = unpack('C', substr($self->data, $ptr));
68    $ptr++;
69
70    my $extensions_len = unpack('n', substr($self->data, $ptr));
71    if (!defined $extensions_len) {
72        $extensions_len = 0;
73    } else {
74        $ptr += 2;
75    }
76    #For now we just deal with this as a block of data. In the future we will
77    #want to parse this
78    my $extension_data;
79    if ($extensions_len != 0) {
80        $extension_data = substr($self->data, $ptr);
81
82        if (length($extension_data) != $extensions_len) {
83            die "Invalid extension length\n";
84        }
85    } else {
86        if (length($self->data) != $ptr) {
87            die "Invalid extension length\n";
88        }
89        $extension_data = "";
90    }
91    my %extensions = ();
92    while (length($extension_data) >= 4) {
93        my ($type, $size) = unpack("nn", $extension_data);
94        my $extdata = substr($extension_data, 4, $size);
95        $extension_data = substr($extension_data, 4 + $size);
96        $extensions{$type} = $extdata;
97        if ($type == TLSProxy::Message::EXT_SUPPORTED_VERSIONS) {
98            $neg_version = unpack('n', $extdata);
99        }
100    }
101
102    if ($random eq $hrrrandom) {
103        TLSProxy::Proxy->is_tls13(1);
104    } elsif ($neg_version == TLSProxy::Record::VERS_TLS_1_3) {
105        TLSProxy::Proxy->is_tls13(1);
106
107        TLSProxy::Record->server_encrypting(1);
108        TLSProxy::Record->client_encrypting(1);
109    }
110
111    $self->server_version($server_version);
112    $self->random($random);
113    $self->session_id_len($session_id_len);
114    $self->session($session);
115    $self->ciphersuite($ciphersuite);
116    TLSProxy::Proxy->ciphersuite($ciphersuite);
117    $self->comp_meth($comp_meth);
118    $self->extension_data(\%extensions);
119
120    $self->process_data();
121
122
123    print "    Server Version:".$server_version."\n";
124    print "    Session ID Len:".$session_id_len."\n";
125    print "    Ciphersuite:".$ciphersuite."\n";
126    print "    Compression Method:".$comp_meth."\n";
127    print "    Extensions Len:".$extensions_len."\n";
128}
129
130#Perform any actions necessary based on the data we've seen
131sub process_data
132{
133    my $self = shift;
134
135    TLSProxy::Message->ciphersuite($self->ciphersuite);
136}
137
138#Reconstruct the on-the-wire message data following changes
139sub set_message_contents
140{
141    my $self = shift;
142    my $data;
143    my $extensions = "";
144
145    $data = pack('n', $self->server_version);
146    $data .= $self->random;
147    $data .= pack('C', $self->session_id_len);
148    $data .= $self->session;
149    $data .= pack('n', $self->ciphersuite);
150    $data .= pack('C', $self->comp_meth);
151
152    foreach my $key (keys %{$self->extension_data}) {
153        my $extdata = ${$self->extension_data}{$key};
154        $extensions .= pack("n", $key);
155        $extensions .= pack("n", length($extdata));
156        $extensions .= $extdata;
157        if ($key == $self->dupext) {
158          $extensions .= pack("n", $key);
159          $extensions .= pack("n", length($extdata));
160          $extensions .= $extdata;
161        }
162    }
163
164    $data .= pack('n', length($extensions));
165    $data .= $extensions;
166    $self->data($data);
167}
168
169#Read/write accessors
170sub server_version
171{
172    my $self = shift;
173    if (@_) {
174      $self->{server_version} = shift;
175    }
176    return $self->{server_version};
177}
178sub random
179{
180    my $self = shift;
181    if (@_) {
182      $self->{random} = shift;
183    }
184    return $self->{random};
185}
186sub session_id_len
187{
188    my $self = shift;
189    if (@_) {
190      $self->{session_id_len} = shift;
191    }
192    return $self->{session_id_len};
193}
194sub session
195{
196    my $self = shift;
197    if (@_) {
198      $self->{session} = shift;
199    }
200    return $self->{session};
201}
202sub ciphersuite
203{
204    my $self = shift;
205    if (@_) {
206      $self->{ciphersuite} = shift;
207    }
208    return $self->{ciphersuite};
209}
210sub comp_meth
211{
212    my $self = shift;
213    if (@_) {
214      $self->{comp_meth} = shift;
215    }
216    return $self->{comp_meth};
217}
218sub extension_data
219{
220    my $self = shift;
221    if (@_) {
222      $self->{extension_data} = shift;
223    }
224    return $self->{extension_data};
225}
226sub set_extension
227{
228    my ($self, $ext_type, $ext_data) = @_;
229    $self->{extension_data}{$ext_type} = $ext_data;
230}
231sub delete_extension
232{
233    my ($self, $ext_type) = @_;
234    delete $self->{extension_data}{$ext_type};
235}
2361;
237