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1# Copyright 2016 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::ClientHello;
11
12use vars '@ISA';
13push @ISA, 'TLSProxy::Message';
14
15sub 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        1,
27        $data,
28        $records,
29        $startoffset,
30        $message_frag_lens);
31
32    $self->{client_version} = 0;
33    $self->{random} = [];
34    $self->{session_id_len} = 0;
35    $self->{session} = "";
36    $self->{ciphersuite_len} = 0;
37    $self->{ciphersuites} = [];
38    $self->{comp_meth_len} = 0;
39    $self->{comp_meths} = [];
40    $self->{extensions_len} = 0;
41    $self->{extension_data} = "";
42
43    return $self;
44}
45
46sub parse
47{
48    my $self = shift;
49    my $ptr = 2;
50    my ($client_version) = unpack('n', $self->data);
51    my $random = substr($self->data, $ptr, 32);
52    $ptr += 32;
53    my $session_id_len = unpack('C', substr($self->data, $ptr));
54    $ptr++;
55    my $session = substr($self->data, $ptr, $session_id_len);
56    $ptr += $session_id_len;
57    my $ciphersuite_len = unpack('n', substr($self->data, $ptr));
58    $ptr += 2;
59    my @ciphersuites = unpack('n*', substr($self->data, $ptr,
60                                           $ciphersuite_len));
61    $ptr += $ciphersuite_len;
62    my $comp_meth_len = unpack('C', substr($self->data, $ptr));
63    $ptr++;
64    my @comp_meths = unpack('C*', substr($self->data, $ptr, $comp_meth_len));
65    $ptr += $comp_meth_len;
66    my $extensions_len = unpack('n', substr($self->data, $ptr));
67    $ptr += 2;
68    #For now we just deal with this as a block of data. In the future we will
69    #want to parse this
70    my $extension_data = substr($self->data, $ptr);
71
72    if (length($extension_data) != $extensions_len) {
73        die "Invalid extension length\n";
74    }
75    my %extensions = ();
76    while (length($extension_data) >= 4) {
77        my ($type, $size) = unpack("nn", $extension_data);
78        my $extdata = substr($extension_data, 4, $size);
79        $extension_data = substr($extension_data, 4 + $size);
80        $extensions{$type} = $extdata;
81    }
82
83    $self->client_version($client_version);
84    $self->random($random);
85    $self->session_id_len($session_id_len);
86    $self->session($session);
87    $self->ciphersuite_len($ciphersuite_len);
88    $self->ciphersuites(\@ciphersuites);
89    $self->comp_meth_len($comp_meth_len);
90    $self->comp_meths(\@comp_meths);
91    $self->extensions_len($extensions_len);
92    $self->extension_data(\%extensions);
93
94    $self->process_extensions();
95
96    print "    Client Version:".$client_version."\n";
97    print "    Session ID Len:".$session_id_len."\n";
98    print "    Ciphersuite len:".$ciphersuite_len."\n";
99    print "    Compression Method Len:".$comp_meth_len."\n";
100    print "    Extensions Len:".$extensions_len."\n";
101}
102
103#Perform any actions necessary based on the extensions we've seen
104sub process_extensions
105{
106    my $self = shift;
107    my %extensions = %{$self->extension_data};
108
109    #Clear any state from a previous run
110    TLSProxy::Record->etm(0);
111
112    if (exists $extensions{TLSProxy::Message::EXT_ENCRYPT_THEN_MAC}) {
113        TLSProxy::Record->etm(1);
114    }
115}
116
117sub extension_contents
118{
119    my $self = shift;
120    my $key = shift;
121    my $extension = "";
122
123    my $extdata = ${$self->extension_data}{$key};
124    $extension .= pack("n", $key);
125    $extension .= pack("n", length($extdata));
126    $extension .= $extdata;
127    return $extension;
128}
129
130#Reconstruct the on-the-wire message data following changes
131sub set_message_contents
132{
133    my $self = shift;
134    my $data;
135    my $extensions = "";
136
137    $data = pack('n', $self->client_version);
138    $data .= $self->random;
139    $data .= pack('C', $self->session_id_len);
140    $data .= $self->session;
141    $data .= pack('n', $self->ciphersuite_len);
142    $data .= pack("n*", @{$self->ciphersuites});
143    $data .= pack('C', $self->comp_meth_len);
144    $data .= pack("C*", @{$self->comp_meths});
145
146    foreach my $key (keys %{$self->extension_data}) {
147        next if ($key == TLSProxy::Message::EXT_PSK);
148        $extensions .= $self->extension_contents($key);
149        #Add extension twice if we are duplicating that extension
150        $extensions .= $self->extension_contents($key) if ($key == $self->dupext);
151    }
152    #PSK extension always goes last...
153    if (defined ${$self->extension_data}{TLSProxy::Message::EXT_PSK}) {
154        $extensions .= $self->extension_contents(TLSProxy::Message::EXT_PSK);
155    }
156    #unless we have EXT_FORCE_LAST
157    if (defined ${$self->extension_data}{TLSProxy::Message::EXT_FORCE_LAST}) {
158        $extensions .= $self->extension_contents(TLSProxy::Message::EXT_FORCE_LAST);
159    }
160
161    $data .= pack('n', length($extensions));
162    $data .= $extensions;
163
164    $self->data($data);
165}
166
167#Read/write accessors
168sub client_version
169{
170    my $self = shift;
171    if (@_) {
172      $self->{client_version} = shift;
173    }
174    return $self->{client_version};
175}
176sub random
177{
178    my $self = shift;
179    if (@_) {
180      $self->{random} = shift;
181    }
182    return $self->{random};
183}
184sub session_id_len
185{
186    my $self = shift;
187    if (@_) {
188      $self->{session_id_len} = shift;
189    }
190    return $self->{session_id_len};
191}
192sub session
193{
194    my $self = shift;
195    if (@_) {
196      $self->{session} = shift;
197    }
198    return $self->{session};
199}
200sub ciphersuite_len
201{
202    my $self = shift;
203    if (@_) {
204      $self->{ciphersuite_len} = shift;
205    }
206    return $self->{ciphersuite_len};
207}
208sub ciphersuites
209{
210    my $self = shift;
211    if (@_) {
212      $self->{ciphersuites} = shift;
213    }
214    return $self->{ciphersuites};
215}
216sub comp_meth_len
217{
218    my $self = shift;
219    if (@_) {
220      $self->{comp_meth_len} = shift;
221    }
222    return $self->{comp_meth_len};
223}
224sub comp_meths
225{
226    my $self = shift;
227    if (@_) {
228      $self->{comp_meths} = shift;
229    }
230    return $self->{comp_meths};
231}
232sub extensions_len
233{
234    my $self = shift;
235    if (@_) {
236      $self->{extensions_len} = shift;
237    }
238    return $self->{extensions_len};
239}
240sub extension_data
241{
242    my $self = shift;
243    if (@_) {
244      $self->{extension_data} = shift;
245    }
246    return $self->{extension_data};
247}
248sub set_extension
249{
250    my ($self, $ext_type, $ext_data) = @_;
251    $self->{extension_data}{$ext_type} = $ext_data;
252}
253sub delete_extension
254{
255    my ($self, $ext_type) = @_;
256    delete $self->{extension_data}{$ext_type};
257}
2581;
259