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Extend ServerKeyExchange parsing to work with a signature

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Previously SKE in TLSProxy only knew about one anonymous ciphersuite so
there was never a signature. Extend that to include a ciphersuite that is
not anonymous. This also fixes a bug where the existing SKE processing was
checking against the wrong anon ciphersuite value. This has a knock on
impact on the sslskewith0p test. The bug meant the test was working...but
entirely by accident!

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
This commit is contained in:
Matt Caswell 2017-01-05 12:32:06 +00:00
parent adb403dea9
commit 79d8c16785
3 changed files with 38 additions and 13 deletions
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1
test/recipes/70-test_sslskewith0p.t
View file

@ -41,6 +41,7 @@ my $proxy = TLSProxy::Proxy->new(
$proxy->cipherc('ADH-AES128-SHA:@SECLEVEL=0');
$proxy->ciphers('ADH-AES128-SHA:@SECLEVEL=0');
$proxy->clientflags("-no_tls1_3");
$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
plan tests => 1;
ok(TLSProxy::Message->fail, "ServerKeyExchange with 0 p");

3
util/TLSProxy/Message.pm
View file

@ -84,7 +84,8 @@ use constant {
};
use constant {
CIPHER_ADH_AES_128_SHA => 0x03000034
CIPHER_DHE_RSA_AES_128_SHA => 0x0033,
CIPHER_ADH_AES_128_SHA => 0x0034
};
my $payload = "";

47
util/TLSProxy/ServerKeyExchange.pm
View file

@ -33,6 +33,7 @@ sub new
$self->{p} = "";
$self->{g} = "";
$self->{pub_key} = "";
$self->{sigalg} = -1;
$self->{sig} = "";
return $self;
@ -41,10 +42,13 @@ sub new
sub parse
{
my $self = shift;
my $sigalg = -1;
#Minimal SKE parsing. Only supports one known DHE ciphersuite at the moment
return if (TLSProxy::Proxy->ciphersuite()
!= TLSProxy::Message::CIPHER_ADH_AES_128_SHA);
return if TLSProxy::Proxy->ciphersuite()
!= TLSProxy::Message::CIPHER_ADH_AES_128_SHA
&& TLSProxy::Proxy->ciphersuite()
!= TLSProxy::Message::CIPHER_DHE_RSA_AES_128_SHA;
my $p_len = unpack('n', $self->data);
my $ptr = 2;
@ -62,18 +66,28 @@ sub parse
$ptr += $pub_key_len;
#We assume its signed
my $sig_len = unpack('n', substr($self->data, $ptr));
my $record = ${$self->records}[0];
if (TLSProxy::Proxy->is_tls13()
|| $record->version() == TLSProxy::Record::VERS_TLS_1_2) {
$sigalg = unpack('n', substr($self->data, $ptr));
$ptr += 2;
}
my $sig = "";
if (defined $sig_len) {
$ptr += 2;
$sig = substr($self->data, $ptr, $sig_len);
$ptr += $sig_len;
if (defined $sigalg) {
my $sig_len = unpack('n', substr($self->data, $ptr));
if (defined $sig_len) {
$ptr += 2;
$sig = substr($self->data, $ptr, $sig_len);
$ptr += $sig_len;
}
}
$self->p($p);
$self->g($g);
$self->pub_key($pub_key);
$self->sig($sig);
$self->sigalg($sigalg) if defined $sigalg;
$self->signature($sig);
}
@ -89,9 +103,10 @@ sub set_message_contents
$data .= $self->g;
$data .= pack('n', length($self->pub_key));
$data .= $self->pub_key;
if (length($self->sig) > 0) {
$data .= pack('n', length($self->sig));
$data .= $self->sig;
$data .= pack('n', $self->sigalg) if ($self->sigalg != -1);
if (length($self->signature) > 0) {
$data .= pack('n', length($self->signature));
$data .= $self->signature;
}
$self->data($data);
@ -123,7 +138,15 @@ sub pub_key
}
return $self->{pub_key};
}
sub sig
sub sigalg
{
my $self = shift;
if (@_) {
$self->{sigalg} = shift;
}
return $self->{sigalg};
}
sub signature
{
my $self = shift;
if (@_) {