Add some tests for the key_share extension

#! /usr/bin/env perl

# Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.

#

# Licensed under the OpenSSL license (the "License").  You may not use

# this file except in compliance with the License.  You can obtain a copy

# in the file LICENSE in the source distribution or at

# https://www.openssl.org/source/license.html

use strict;

use OpenSSL::Test qw/:DEFAULT cmdstr srctop_file bldtop_dir/;

use OpenSSL::Test::Utils;

use TLSProxy::Proxy;

use File::Temp qw(tempfile);

use constant {

    LOOK_ONLY => 0,

    EMPTY_EXTENSION => 1,

    MISSING_EXTENSION => 2,

    NO_ACCEPTABLE_KEY_SHARES => 3,

    NON_PREFERRED_KEY_SHARE => 4,

    ACCEPTABLE_AT_END => 5,

    NOT_IN_SUPPORTED_GROUPS => 6,

    GROUP_ID_TOO_SHORT => 7,

    KEX_LEN_MISMATCH => 8,

    ZERO_LEN_KEX_DATA => 9,

    TRAILING_DATA => 10,

    SELECT_X25519 => 11

};

use constant {

    CLIENT_TO_SERVER => 1,

    SERVER_TO_CLIENT => 2

};

use constant {

    X25519 => 0x1d,

    P_256 => 0x17

};

my $testtype;

my $direction;

my $selectedgroupid;

my $test_name = "test_key_share";

setup($test_name);

plan skip_all => "TLSProxy isn't usable on $^O"

    if $^O =~ /^(VMS|MSWin32)$/;

plan skip_all => "$test_name needs the dynamic engine feature enabled"

    if disabled("engine") || disabled("dynamic-engine");

plan skip_all => "$test_name needs the sock feature enabled"

    if disabled("sock");

plan skip_all => "$test_name needs TLS1.3 enabled"

    if disabled("tls1_3");

$ENV{OPENSSL_ia32cap} = '~0x200000200000000';

my $proxy = TLSProxy::Proxy->new(

    undef,

    cmdstr(app(["openssl"]), display => 1),

    srctop_file("apps", "server.pem"),

    (!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})

);

#We assume that test_ssl_new and friends will test the happy path for this,

#so we concentrate on the less common scenarios

#Test 1: An empty key_shares extension should not succeed

$testtype = EMPTY_EXTENSION;

$direction = CLIENT_TO_SERVER;

$proxy->filter(\&modify_key_shares_filter);

$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";

plan tests => 17;

#TODO(TLS1.3): Actually this should succeed after a HelloRetryRequest - but

#we've not implemented that yet, so for now we look for a fail

ok(TLSProxy::Message->fail(), "Empty key_shares");

#Test 2: A missing key_shares extension should not succeed

$proxy->clear();

$testtype = MISSING_EXTENSION;

$proxy->start();

#TODO(TLS1.3): As above this should really succeed after a HelloRetryRequest,

#but we look for fail for now

ok(TLSProxy::Message->fail(), "Missing key_shares extension");

#Test 3: No acceptable key_shares should fail

$proxy->clear();

$testtype = NO_ACCEPTABLE_KEY_SHARES;

$proxy->start();

#TODO(TLS1.3): Again this should go around the loop of a HelloRetryRequest but

#we fail for now

ok(TLSProxy::Message->fail(), "No acceptable key_shares");

#Test 4: A non preferred but acceptable key_share should succeed

$proxy->clear();

$proxy->filter(undef);

$proxy->clientflags("-curves P-256");

$proxy->start();

ok(TLSProxy::Message->success(), "Non preferred key_share");

$proxy->filter(\&modify_key_shares_filter);

#Test 5: An acceptable key_share after a list of non-acceptable ones should

#succeed

$proxy->clear();

$testtype = ACCEPTABLE_AT_END;

$proxy->start();

ok(TLSProxy::Message->success(), "Acceptable key_share at end of list");

#Test 6: An acceptable key_share but for a group not in supported_groups should

#fail

$proxy->clear();

$testtype = NOT_IN_SUPPORTED_GROUPS;

$proxy->start();

ok(TLSProxy::Message->fail(), "Acceptable key_share not in supported_groups");

#Test 7: Too short group_id should fail

$proxy->clear();

$testtype = GROUP_ID_TOO_SHORT;

$proxy->start();

ok(TLSProxy::Message->fail(), "Group id too short");

#Test 8: key_exchange length mismatch should fail

$proxy->clear();

$testtype = KEX_LEN_MISMATCH;

$proxy->start();

ok(TLSProxy::Message->fail(), "key_exchange length mismatch");

#Test 9: Zero length key_exchange should fail

$proxy->clear();

$testtype = ZERO_LEN_KEX_DATA;

$proxy->start();

ok(TLSProxy::Message->fail(), "zero length key_exchange data");

#Test 10: Trailing data on key_share list should fail

$proxy->clear();

$testtype = TRAILING_DATA;

$proxy->start();

ok(TLSProxy::Message->fail(), "key_share list trailing data");

#Test 11: Multiple acceptable key_shares - we choose the first one

$proxy->clear();

$direction = SERVER_TO_CLIENT;

$testtype = LOOK_ONLY;

$proxy->clientflags("-curves P-256:X25519");

$proxy->start();

ok(TLSProxy::Message->success() && ($selectedgroupid == P_256),

   "Multiple acceptable key_shares");

#Test 12: Multiple acceptable key_shares - we choose the first one (part 2)

$proxy->clear();

$proxy->clientflags("-curves X25519:P-256");

$proxy->start();

ok(TLSProxy::Message->success() && ($selectedgroupid == X25519),

   "Multiple acceptable key_shares (part 2)");

#Test 13: Server sends key_share that wasn't offerred should fail

$proxy->clear();

$testtype = SELECT_X25519;

$proxy->clientflags("-curves P-256");

$proxy->start();

ok(TLSProxy::Message->fail(), "Non offered key_share");

#Test 14: Too short group_id in ServerHello should fail

$proxy->clear();

$testtype = GROUP_ID_TOO_SHORT;

$proxy->start();

ok(TLSProxy::Message->fail(), "Group id too short in ServerHello");

#Test 15: key_exchange length mismatch in ServerHello should fail

$proxy->clear();

$testtype = KEX_LEN_MISMATCH;

$proxy->start();

ok(TLSProxy::Message->fail(), "key_exchange length mismatch in ServerHello");

#Test 16: Zero length key_exchange in ServerHello should fail

$proxy->clear();

$testtype = ZERO_LEN_KEX_DATA;

$proxy->start();

ok(TLSProxy::Message->fail(), "zero length key_exchange data in ServerHello");

#Test 17: Trailing data on key_share in ServerHello should fail

$proxy->clear();

$testtype = TRAILING_DATA;

$proxy->start();

ok(TLSProxy::Message->fail(), "key_share trailing data in ServerHello");

sub modify_key_shares_filter

{

    my $proxy = shift;

    # We're only interested in the initial ClientHello

    if (($direction == CLIENT_TO_SERVER && $proxy->flight != 0)

            || ($direction == SERVER_TO_CLIENT && $proxy->flight != 1)) {

        return;

    }

    foreach my $message (@{$proxy->message_list}) {

        if ($message->mt == TLSProxy::Message::MT_CLIENT_HELLO

                && $direction == CLIENT_TO_SERVER) {

            my $ext;

            my $suppgroups;

            #Setup supported groups to include some unrecognised groups

            $suppgroups = pack "C8",

                0x00, 0x06, #List Length

                0xff, 0xfe, #Non existing group 1

                0xff, 0xff, #Non existing group 2

                0x00, 0x1d; #x25519

            if ($testtype == EMPTY_EXTENSION) {

                $ext = pack "C2",

                    0x00, 0x00;

            } elsif ($testtype == NO_ACCEPTABLE_KEY_SHARES) {

                $ext = pack "C12",

                    0x00, 0x0a, #List Length

                    0xff, 0xfe, #Non existing group 1

                    0x00, 0x01, 0xff, #key_exchange data

                    0xff, 0xff, #Non existing group 2

                    0x00, 0x01, 0xff; #key_exchange data

            } elsif ($testtype == ACCEPTABLE_AT_END) {

                $ext = pack "C11H64",

                    0x00, 0x29, #List Length

                    0xff, 0xfe, #Non existing group 1

                    0x00, 0x01, 0xff, #key_exchange data

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data

            } elsif ($testtype == NOT_IN_SUPPORTED_GROUPS) {

                $suppgroups = pack "C4",

                    0x00, 0x02, #List Length

                    0x00, 0xfe; #Non existing group 1

            } elsif ($testtype == GROUP_ID_TOO_SHORT) {

                $ext = pack "C6H64C1",

                    0x00, 0x25, #List Length

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data

                    0x00;       #Group id too short

            } elsif ($testtype == KEX_LEN_MISMATCH) {

                $ext = pack "C8",

                    0x00, 0x06, #List Length

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    0x15, 0x51; #Only two bytes of data, but length should be 32

            } elsif ($testtype == ZERO_LEN_KEX_DATA) {

                $ext = pack "C10H64",

                    0x00, 0x28, #List Length

                    0xff, 0xfe, #Non existing group 1

                    0x00, 0x00, #zero length key_exchange data is invalid

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data

            } elsif ($testtype == TRAILING_DATA) {

                $ext = pack "C6H64C1",

                    0x00, 0x24, #List Length

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421", #key_exchange data

                    0x00; #Trailing garbage

            }

            $message->set_extension(

                TLSProxy::Message::EXT_SUPPORTED_GROUPS, $suppgroups);

            if ($testtype == MISSING_EXTENSION) {

                $message->delete_extension(

                    TLSProxy::Message::EXT_KEY_SHARE);

            } elsif ($testtype != NOT_IN_SUPPORTED_GROUPS) {

                $message->set_extension(

                    TLSProxy::Message::EXT_KEY_SHARE, $ext);

            }

            $message->repack();

        } elsif ($message->mt == TLSProxy::Message::MT_SERVER_HELLO

                     && $direction == SERVER_TO_CLIENT) {

            my $ext;

            my $key_share =

                ${$message->extension_data}{TLSProxy::Message::EXT_KEY_SHARE};

            $selectedgroupid = unpack("n", $key_share);

            if ($testtype == LOOK_ONLY) {

                return;

            }

            if ($testtype == SELECT_X25519) {

                $ext = pack "C4H64",

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data

            } elsif ($testtype == GROUP_ID_TOO_SHORT) {

                $ext = pack "C1",

                    0x00;

            } elsif ($testtype == KEX_LEN_MISMATCH) {

                $ext = pack "C6",

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    0x15, 0x51; #Only two bytes of data, but length should be 32

            } elsif ($testtype == ZERO_LEN_KEX_DATA) {

                $ext = pack "C4",

                    0x00, 0x1d, #x25519

                    0x00, 0x00, #zero length key_exchange data is invalid

            } elsif ($testtype == TRAILING_DATA) {

                $ext = pack "C4H64C1",

                    0x00, 0x1d, #x25519

                    0x00, 0x20, #key_exchange data length

                    "155155B95269ED5C87EAA99C2EF5A593".

                    "EDF83495E80380089F831B94D14B1421", #key_exchange data

                    0x00; #Trailing garbage

            }

            $message->set_extension( TLSProxy::Message::EXT_KEY_SHARE, $ext);

            $message->repack();

        }

    }

}

use constant {

    EXT_STATUS_REQUEST => 5,

    EXT_SUPPORTED_GROUPS => 10,

    EXT_ENCRYPT_THEN_MAC => 22,

    EXT_EXTENDED_MASTER_SECRET => 23,

    EXT_SESSION_TICKET => 35,

    EXT_SUPPORTED_VERSIONS => 43,

    EXT_KEY_SHARE => 40,

    # This extension does not exist and isn't recognised by OpenSSL.

    # We use it to test handling of duplicate extensions.

    EXT_DUPLICATE_EXTENSION => 1234