test/recipes/70-test_key_share.t - platform/external/openssl - Git at Google


            
            #! /usr/bin/env perl

            
            # Copyright 2015-2018 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,

            
                NO_KEY_SHARES_IN_HRR => 12

            
            };


            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 $^O =~ /^(VMS)$/;


            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 succeed after a HelloRetryRequest

            
            $testtype = EMPTY_EXTENSION;

            
            $direction = CLIENT_TO_SERVER;

            
            $proxy->filter(\&modify_key_shares_filter);

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

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

            
            plan tests => 22;

            
            ok(TLSProxy::Message->success(), "Success after HRR");


            #Test 2: The server sending an HRR requesting a group the client already sent

            
            #        should fail

            
            $proxy->clear();

            
            $proxy->start();

            
            ok(TLSProxy::Message->fail(), "Server asks for group already provided");


            #Test 3: A missing key_shares extension should not succeed

            
            $proxy->clear();

            
            $testtype = MISSING_EXTENSION;

            
            $proxy->start();

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


            #Test 4: No initial acceptable key_shares should succeed after a

            
            #        HelloRetryRequest

            
            $proxy->clear();

            
            $proxy->filter(undef);

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

            
            $proxy->start();

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


            #Test 5: No acceptable key_shares and no shared groups should fail

            
            $proxy->clear();

            
            $proxy->filter(undef);

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

            
            $proxy->clientflags("-curves P-384");

            
            $proxy->start();

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


            #Test 6: A non preferred but acceptable key_share should succeed

            
            $proxy->clear();

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

            
            $proxy->start();

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

            
            $proxy->filter(\&modify_key_shares_filter);


            #Test 7: 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 8: 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 9: Too short group_id should fail

            
            $proxy->clear();

            
            $testtype = GROUP_ID_TOO_SHORT;

            
            $proxy->start();

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


            #Test 10: key_exchange length mismatch should fail

            
            $proxy->clear();

            
            $testtype = KEX_LEN_MISMATCH;

            
            $proxy->start();

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


            #Test 11: 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 12: 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 13: 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 14: 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 15: Server sends key_share that wasn't offered should fail

            
            $proxy->clear();

            
            $testtype = SELECT_X25519;

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

            
            $proxy->start();

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


            #Test 16: 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 17: 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 18: 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 19: 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");


            SKIP: {

            
                skip "No TLSv1.2 support in this OpenSSL build", 2 if disabled("tls1_2");


                #Test 20: key_share should not be sent if the client is not capable of

            
                #         negotiating TLSv1.3

            
                $proxy->clear();

            
                $proxy->filter(undef);

            
                $proxy->clientflags("-no_tls1_3");

            
                $proxy->start();

            
                my $clienthello = $proxy->message_list->[0];

            
                ok(TLSProxy::Message->success()

            
                   && !defined $clienthello->extension_data->{TLSProxy::Message::EXT_KEY_SHARE},

            
                   "No key_share for TLS<=1.2 client");

            
                $proxy->filter(\&modify_key_shares_filter);


                #Test 21: A server not capable of negotiating TLSv1.3 should not attempt to

            
                #         process a key_share

            
                $proxy->clear();

            
                $direction = CLIENT_TO_SERVER;

            
                $testtype = NO_ACCEPTABLE_KEY_SHARES;

            
                $proxy->serverflags("-no_tls1_3");

            
                $proxy->start();

            
                ok(TLSProxy::Message->success(), "Ignore key_share for TLS<=1.2 server");

            
            }


            #Test 22: The server sending an HRR but not requesting a new key_share should

            
            #         fail

            
            $proxy->clear();

            
            $direction = SERVER_TO_CLIENT;

            
            $testtype = NO_KEY_SHARES_IN_HRR;

            
            $proxy->serverflags("-curves X25519");

            
            $proxy->start();

            
            ok(TLSProxy::Message->fail(), "Server sends HRR with no key_shares");


            sub modify_key_shares_filter

            
            {

            
                my $proxy = shift;


                # We're only interested in the initial ClientHello

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

            
                            && ($proxy->flight != 1 || $testtype != NO_KEY_SHARES_IN_HRR))

            
                        || ($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

            
                        } elsif ($testtype == NO_KEY_SHARES_IN_HRR) {

            
                            #We trick the server into thinking we sent a P-256 key_share -

            
                            #but the client actually sent X25519

            
                            $ext = pack "C7",

            
                                0x00, 0x05, #List Length

            
                                0x00, 0x17, #P-256

            
                                0x00, 0x01, #key_exchange data length

            
                                0xff;       #Dummy key_share data

            
                        }


                        if ($testtype != EMPTY_EXTENSION

            
                                && $testtype != NO_KEY_SHARES_IN_HRR) {

            
                            $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 == NO_KEY_SHARES_IN_HRR) {

            
                            $message->delete_extension(TLSProxy::Message::EXT_KEY_SHARE);

            
                            $message->set_extension(TLSProxy::Message::EXT_UNKNOWN, "");

            
                            $message->repack();

            
                            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();

            
                    }

            
                }

            
            }
	#! /usr/bin/env perl
	# Copyright 2015-2018 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,
	NO_KEY_SHARES_IN_HRR => 12
	};

	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 $^O =~ /^(VMS)$/;

	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 succeed after a HelloRetryRequest
	$testtype = EMPTY_EXTENSION;
	$direction = CLIENT_TO_SERVER;
	$proxy->filter(\&modify_key_shares_filter);
	$proxy->serverflags("-curves P-256");
	$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
	plan tests => 22;
	ok(TLSProxy::Message->success(), "Success after HRR");

	#Test 2: The server sending an HRR requesting a group the client already sent
	# should fail
	$proxy->clear();
	$proxy->start();
	ok(TLSProxy::Message->fail(), "Server asks for group already provided");

	#Test 3: A missing key_shares extension should not succeed
	$proxy->clear();
	$testtype = MISSING_EXTENSION;
	$proxy->start();
	ok(TLSProxy::Message->fail(), "Missing key_shares extension");

	#Test 4: No initial acceptable key_shares should succeed after a
	# HelloRetryRequest
	$proxy->clear();
	$proxy->filter(undef);
	$proxy->serverflags("-curves P-256");
	$proxy->start();
	ok(TLSProxy::Message->success(), "No initial acceptable key_shares");

	#Test 5: No acceptable key_shares and no shared groups should fail
	$proxy->clear();
	$proxy->filter(undef);
	$proxy->serverflags("-curves P-256");
	$proxy->clientflags("-curves P-384");
	$proxy->start();
	ok(TLSProxy::Message->fail(), "No acceptable key_shares");

	#Test 6: A non preferred but acceptable key_share should succeed
	$proxy->clear();
	$proxy->clientflags("-curves P-256");
	$proxy->start();
	ok(TLSProxy::Message->success(), "Non preferred key_share");
	$proxy->filter(\&modify_key_shares_filter);

	#Test 7: 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 8: 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 9: Too short group_id should fail
	$proxy->clear();
	$testtype = GROUP_ID_TOO_SHORT;
	$proxy->start();
	ok(TLSProxy::Message->fail(), "Group id too short");

	#Test 10: key_exchange length mismatch should fail
	$proxy->clear();
	$testtype = KEX_LEN_MISMATCH;
	$proxy->start();
	ok(TLSProxy::Message->fail(), "key_exchange length mismatch");

	#Test 11: 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 12: 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 13: 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 14: 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 15: Server sends key_share that wasn't offered should fail
	$proxy->clear();
	$testtype = SELECT_X25519;
	$proxy->clientflags("-curves P-256");
	$proxy->start();
	ok(TLSProxy::Message->fail(), "Non offered key_share");

	#Test 16: 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 17: 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 18: 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 19: 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");

	SKIP: {
	skip "No TLSv1.2 support in this OpenSSL build", 2 if disabled("tls1_2");

	#Test 20: key_share should not be sent if the client is not capable of
	# negotiating TLSv1.3
	$proxy->clear();
	$proxy->filter(undef);
	$proxy->clientflags("-no_tls1_3");
	$proxy->start();
	my $clienthello = $proxy->message_list->[0];
	ok(TLSProxy::Message->success()
	&& !defined $clienthello->extension_data->{TLSProxy::Message::EXT_KEY_SHARE},
	"No key_share for TLS<=1.2 client");
	$proxy->filter(\&modify_key_shares_filter);

	#Test 21: A server not capable of negotiating TLSv1.3 should not attempt to
	# process a key_share
	$proxy->clear();
	$direction = CLIENT_TO_SERVER;
	$testtype = NO_ACCEPTABLE_KEY_SHARES;
	$proxy->serverflags("-no_tls1_3");
	$proxy->start();
	ok(TLSProxy::Message->success(), "Ignore key_share for TLS<=1.2 server");
	}

	#Test 22: The server sending an HRR but not requesting a new key_share should
	# fail
	$proxy->clear();
	$direction = SERVER_TO_CLIENT;
	$testtype = NO_KEY_SHARES_IN_HRR;
	$proxy->serverflags("-curves X25519");
	$proxy->start();
	ok(TLSProxy::Message->fail(), "Server sends HRR with no key_shares");

	sub modify_key_shares_filter
	{
	my $proxy = shift;

	# We're only interested in the initial ClientHello
	if (($direction == CLIENT_TO_SERVER && $proxy->flight != 0
	&& ($proxy->flight != 1 \|\| $testtype != NO_KEY_SHARES_IN_HRR))
	\|\| ($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) {
	$ext = pack "C6H64C1",
	0x00, 0x24, #List Length
	0x00, 0x1d, #x25519
	0x00, 0x20, #key_exchange data length
	"155155B95269ED5C87EAA99C2EF5A593".
	"EDF83495E80380089F831B94D14B1421", #key_exchange data
	0x00; #Trailing garbage
	} elsif ($testtype == NO_KEY_SHARES_IN_HRR) {
	#We trick the server into thinking we sent a P-256 key_share -
	#but the client actually sent X25519
	$ext = pack "C7",
	0x00, 0x05, #List Length
	0x00, 0x17, #P-256
	0x00, 0x01, #key_exchange data length
	0xff; #Dummy key_share data
	}

	if ($testtype != EMPTY_EXTENSION
	&& $testtype != NO_KEY_SHARES_IN_HRR) {
	$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 == NO_KEY_SHARES_IN_HRR) {
	$message->delete_extension(TLSProxy::Message::EXT_KEY_SHARE);
	$message->set_extension(TLSProxy::Message::EXT_UNKNOWN, "");
	$message->repack();
	return;
	}
	if ($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();
	}
	}
	}