xref: /openssl/util/perl/TLSProxy/ServerHello.pm (revision b6461792) 
1# Copyright 2016-2024 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 TLSProxy::Record;
13
14use vars '@ISA';
15push @ISA, 'TLSProxy::Message';
16
17my $hrrrandom = pack("C*", 0xCF, 0x21, 0xAD, 0x74, 0xE5, 0x9A, 0x61, 0x11, 0xBE,
18                           0x1D, 0x8C, 0x02, 0x1E, 0x65, 0xB8, 0x91, 0xC2, 0xA2,
19                           0x11, 0x16, 0x7A, 0xBB, 0x8C, 0x5E, 0x07, 0x9E, 0x09,
20                           0xE2, 0xC8, 0xA8, 0x33, 0x9C);
21
22sub new
23{
24    my $class = shift;
25    my ($isdtls,
26        $server,
27        $msgseq,
28        $msgfrag,
29        $msgfragoffs,
30        $data,
31        $records,
32        $startoffset,
33        $message_frag_lens) = @_;
34
35    my $self = $class->SUPER::new(
36        $isdtls,
37        $server,
38        TLSProxy::Message::MT_SERVER_HELLO,
39        $msgseq,
40        $msgfrag,
41        $msgfragoffs,
42        $data,
43        $records,
44        $startoffset,
45        $message_frag_lens);
46
47    $self->{server_version} = 0;
48    $self->{random} = [];
49    $self->{session_id_len} = 0;
50    $self->{session} = "";
51    $self->{ciphersuite} = 0;
52    $self->{comp_meth} = 0;
53    $self->{extension_data} = "";
54
55    return $self;
56}
57
58sub parse
59{
60    my $self = shift;
61    my $ptr = 2;
62    my ($server_version) = unpack('n', $self->data);
63    my $neg_version = $server_version;
64
65    my $random = substr($self->data, $ptr, 32);
66    $ptr += 32;
67    my $session_id_len = 0;
68    my $session = "";
69    $session_id_len = unpack('C', substr($self->data, $ptr));
70    $ptr++;
71    $session = substr($self->data, $ptr, $session_id_len);
72    $ptr += $session_id_len;
73
74    my $ciphersuite = unpack('n', substr($self->data, $ptr));
75    $ptr += 2;
76    my $comp_meth = 0;
77    $comp_meth = unpack('C', substr($self->data, $ptr));
78    $ptr++;
79
80    my $extensions_len = unpack('n', substr($self->data, $ptr));
81    if (!defined $extensions_len) {
82        $extensions_len = 0;
83    } else {
84        $ptr += 2;
85    }
86    #For now we just deal with this as a block of data. In the future we will
87    #want to parse this
88    my $extension_data;
89    if ($extensions_len != 0) {
90        $extension_data = substr($self->data, $ptr);
91
92        if (length($extension_data) != $extensions_len) {
93            die "Invalid extension length\n";
94        }
95    } else {
96        if (length($self->data) != $ptr) {
97            die "Invalid extension length\n";
98        }
99        $extension_data = "";
100    }
101    my %extensions = ();
102    while (length($extension_data) >= 4) {
103        my ($type, $size) = unpack("nn", $extension_data);
104        my $extdata = substr($extension_data, 4, $size);
105        $extension_data = substr($extension_data, 4 + $size);
106        $extensions{$type} = $extdata;
107        if ($type == TLSProxy::Message::EXT_SUPPORTED_VERSIONS) {
108            $neg_version = unpack('n', $extdata);
109        }
110    }
111
112    if ($random eq $hrrrandom) {
113        TLSProxy::Proxy->is_tls13(1);
114    } elsif ($neg_version == TLSProxy::Record::VERS_TLS_1_3) {
115        TLSProxy::Proxy->is_tls13(1);
116
117        TLSProxy::Record->server_encrypting(1);
118        TLSProxy::Record->client_encrypting(1);
119    }
120
121    $self->server_version($server_version);
122    $self->random($random);
123    $self->session_id_len($session_id_len);
124    $self->session($session);
125    $self->ciphersuite($ciphersuite);
126    TLSProxy::Proxy->ciphersuite($ciphersuite);
127    $self->comp_meth($comp_meth);
128    $self->extension_data(\%extensions);
129
130    $self->process_data();
131
132
133    print "    Server Version:".$TLSProxy::Record::tls_version{$server_version}."\n";
134    print "    Session ID Len:".$session_id_len."\n";
135    print "    Ciphersuite:".$ciphersuite."\n";
136    print "    Compression Method:".$comp_meth."\n";
137    print "    Extensions Len:".$extensions_len."\n";
138}
139
140#Perform any actions necessary based on the data we've seen
141sub process_data
142{
143    my $self = shift;
144
145    TLSProxy::Message->ciphersuite($self->ciphersuite);
146}
147
148#Reconstruct the on-the-wire message data following changes
149sub set_message_contents
150{
151    my $self = shift;
152    my $data;
153    my $extensions = "";
154
155    $data = pack('n', $self->server_version);
156    $data .= $self->random;
157    $data .= pack('C', $self->session_id_len);
158    $data .= $self->session;
159    $data .= pack('n', $self->ciphersuite);
160    $data .= pack('C', $self->comp_meth);
161
162    foreach my $key (keys %{$self->extension_data}) {
163        my $extdata = ${$self->extension_data}{$key};
164        $extensions .= pack("n", $key);
165        $extensions .= pack("n", length($extdata));
166        $extensions .= $extdata;
167        if ($key == $self->dupext) {
168          $extensions .= pack("n", $key);
169          $extensions .= pack("n", length($extdata));
170          $extensions .= $extdata;
171        }
172    }
173
174    $data .= pack('n', length($extensions));
175    $data .= $extensions;
176    $self->data($data);
177}
178
179#Read/write accessors
180sub server_version
181{
182    my $self = shift;
183    if (@_) {
184      $self->{server_version} = shift;
185    }
186    return $self->{server_version};
187}
188sub random
189{
190    my $self = shift;
191    if (@_) {
192      $self->{random} = shift;
193    }
194    return $self->{random};
195}
196sub session_id_len
197{
198    my $self = shift;
199    if (@_) {
200      $self->{session_id_len} = shift;
201    }
202    return $self->{session_id_len};
203}
204sub session
205{
206    my $self = shift;
207    if (@_) {
208      $self->{session} = shift;
209    }
210    return $self->{session};
211}
212sub ciphersuite
213{
214    my $self = shift;
215    if (@_) {
216      $self->{ciphersuite} = shift;
217    }
218    return $self->{ciphersuite};
219}
220sub comp_meth
221{
222    my $self = shift;
223    if (@_) {
224      $self->{comp_meth} = shift;
225    }
226    return $self->{comp_meth};
227}
228sub extension_data
229{
230    my $self = shift;
231    if (@_) {
232      $self->{extension_data} = shift;
233    }
234    return $self->{extension_data};
235}
236sub set_extension
237{
238    my ($self, $ext_type, $ext_data) = @_;
239    $self->{extension_data}{$ext_type} = $ext_data;
240}
241sub delete_extension
242{
243    my ($self, $ext_type) = @_;
244    delete $self->{extension_data}{$ext_type};
245}
2461;
247