util/perl/TLSProxy/ServerKeyExchange.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::ServerKeyExchange;
  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_KEY_EXCHANGE,
  27         $data,
  28         $records,
  29         $startoffset,
  30         $message_frag_lens);
  31
  32     #DHE
  33     $self->{p} = "";
  34     $self->{g} = "";
  35     $self->{pub_key} = "";
  36     $self->{sigalg} = -1;
  37     $self->{sig} = "";
  38
  39     return $self;
  40 }
  41
  42 sub parse
  43 {
  44     my $self = shift;
  45     my $sigalg = -1;
  46
  47     #Minimal SKE parsing. Only supports one known DHE ciphersuite at the moment
  48     return if TLSProxy::Proxy->ciphersuite()
  49                  != TLSProxy::Message::CIPHER_ADH_AES_128_SHA
  50               && TLSProxy::Proxy->ciphersuite()
  51                  != TLSProxy::Message::CIPHER_DHE_RSA_AES_128_SHA;
  52
  53     my $p_len = unpack('n', $self->data);
  54     my $ptr = 2;
  55     my $p = substr($self->data, $ptr, $p_len);
  56     $ptr += $p_len;
  57
  58     my $g_len = unpack('n', substr($self->data, $ptr));
  59     $ptr += 2;
  60     my $g = substr($self->data, $ptr, $g_len);
  61     $ptr += $g_len;
  62
  63     my $pub_key_len = unpack('n', substr($self->data, $ptr));
  64     $ptr += 2;
  65     my $pub_key = substr($self->data, $ptr, $pub_key_len);
  66     $ptr += $pub_key_len;
  67
  68     #We assume its signed
  69     my $record = ${$self->records}[0];
  70
  71     if (TLSProxy::Proxy->is_tls13()
  72             || $record->version() == TLSProxy::Record::VERS_TLS_1_2) {
  73         $sigalg = unpack('n', substr($self->data, $ptr));
  74         $ptr += 2;
  75     }
  76     my $sig = "";
  77     if (defined $sigalg) {
  78         my $sig_len = unpack('n', substr($self->data, $ptr));
  79         if (defined $sig_len) {
  80             $ptr += 2;
  81             $sig = substr($self->data, $ptr, $sig_len);
  82             $ptr += $sig_len;
  83         }
  84     }
  85
  86     $self->p($p);
  87     $self->g($g);
  88     $self->pub_key($pub_key);
  89     $self->sigalg($sigalg) if defined $sigalg;
  90     $self->signature($sig);
  91 }
  92
  93
  94 #Reconstruct the on-the-wire message data following changes
  95 sub set_message_contents
  96 {
  97     my $self = shift;
  98     my $data;
  99
 100     $data = pack('n', length($self->p));
 101     $data .= $self->p;
 102     $data .= pack('n', length($self->g));
 103     $data .= $self->g;
 104     $data .= pack('n', length($self->pub_key));
 105     $data .= $self->pub_key;
 106     $data .= pack('n', $self->sigalg) if ($self->sigalg != -1);
 107     if (length($self->signature) > 0) {
 108         $data .= pack('n', length($self->signature));
 109         $data .= $self->signature;
 110     }
 111
 112     $self->data($data);
 113 }
 114
 115 #Read/write accessors
 116 #DHE
 117 sub p
 118 {
 119     my $self = shift;
 120     if (@_) {
 121       $self->{p} = shift;
 122     }
 123     return $self->{p};
 124 }
 125 sub g
 126 {
 127     my $self = shift;
 128     if (@_) {
 129       $self->{g} = shift;
 130     }
 131     return $self->{g};
 132 }
 133 sub pub_key
 134 {
 135     my $self = shift;
 136     if (@_) {
 137       $self->{pub_key} = shift;
 138     }
 139     return $self->{pub_key};
 140 }
 141 sub sigalg
 142 {
 143     my $self = shift;
 144     if (@_) {
 145       $self->{sigalg} = shift;
 146     }
 147     return $self->{sigalg};
 148 }
 149 sub signature
 150 {
 151     my $self = shift;
 152     if (@_) {
 153       $self->{sig} = shift;
 154     }
 155     return $self->{sig};
 156 }
 157 1;