1#! /usr/bin/env perl
2# Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.
3#
4# Licensed under the Apache License 2.0 (the "License").  You may not use
5# this file except in compliance with the License.  You can obtain a copy
6# in the file LICENSE in the source distribution or at
7# https://www.openssl.org/source/license.html
8
9use strict;
10use OpenSSL::Test qw/:DEFAULT cmdstr srctop_file bldtop_dir/;
11use OpenSSL::Test::Utils;
12use TLSProxy::Proxy;
13use File::Temp qw(tempfile);
14
15use constant {
16    LOOK_ONLY => 0,
17    EMPTY_EXTENSION => 1,
18    MISSING_EXTENSION => 2,
19    NO_ACCEPTABLE_KEY_SHARES => 3,
20    NON_PREFERRED_KEY_SHARE => 4,
21    ACCEPTABLE_AT_END => 5,
22    NOT_IN_SUPPORTED_GROUPS => 6,
23    GROUP_ID_TOO_SHORT => 7,
24    KEX_LEN_MISMATCH => 8,
25    ZERO_LEN_KEX_DATA => 9,
26    TRAILING_DATA => 10,
27    SELECT_X25519 => 11,
28    NO_KEY_SHARES_IN_HRR => 12
29};
30
31use constant {
32    CLIENT_TO_SERVER => 1,
33    SERVER_TO_CLIENT => 2
34};
35
36
37use constant {
38    X25519 => 0x1d,
39    P_256 => 0x17,
40    FFDHE2048 => 0x0100,
41    FFDHE3072 => 0x0101
42};
43
44my $testtype;
45my $direction;
46my $selectedgroupid;
47
48my $test_name = "test_key_share";
49setup($test_name);
50
51plan skip_all => "TLSProxy isn't usable on $^O"
52    if $^O =~ /^(VMS)$/;
53
54plan skip_all => "$test_name needs the dynamic engine feature enabled"
55    if disabled("engine") || disabled("dynamic-engine");
56
57plan skip_all => "$test_name needs the sock feature enabled"
58    if disabled("sock");
59
60plan skip_all => "$test_name needs TLS1.3 enabled"
61    if disabled("tls1_3");
62
63plan skip_all => "$test_name needs EC or DH enabled"
64    if disabled("ec") && disabled("dh");
65
66my $proxy = TLSProxy::Proxy->new(
67    undef,
68    cmdstr(app(["openssl"]), display => 1),
69    srctop_file("apps", "server.pem"),
70    (!$ENV{HARNESS_ACTIVE} || $ENV{HARNESS_VERBOSE})
71);
72
73#We assume that test_ssl_new and friends will test the happy path for this,
74#so we concentrate on the less common scenarios
75
76#Test 1: An empty key_shares extension should succeed after a HelloRetryRequest
77$testtype = EMPTY_EXTENSION;
78$direction = CLIENT_TO_SERVER;
79$proxy->filter(\&modify_key_shares_filter);
80if (disabled("ec")) {
81    $proxy->serverflags("-groups ffdhe3072");
82} else {
83    $proxy->serverflags("-groups P-256");
84}
85$proxy->start() or plan skip_all => "Unable to start up Proxy for tests";
86plan tests => 22;
87ok(TLSProxy::Message->success(), "Success after HRR");
88
89#Test 2: The server sending an HRR requesting a group the client already sent
90#        should fail
91$proxy->clear();
92$proxy->start();
93ok(TLSProxy::Message->fail(), "Server asks for group already provided");
94
95#Test 3: A missing key_shares extension should not succeed
96$proxy->clear();
97$testtype = MISSING_EXTENSION;
98$proxy->start();
99ok(TLSProxy::Message->fail(), "Missing key_shares extension");
100
101#Test 4: No initial acceptable key_shares should succeed after a
102#        HelloRetryRequest
103$proxy->clear();
104$proxy->filter(undef);
105if (disabled("ec")) {
106    $proxy->serverflags("-groups ffdhe3072");
107} else {
108    $proxy->serverflags("-groups P-256");
109}
110$proxy->start();
111ok(TLSProxy::Message->success(), "No initial acceptable key_shares");
112
113#Test 5: No acceptable key_shares and no shared groups should fail
114$proxy->clear();
115$proxy->filter(undef);
116if (disabled("ec")) {
117    $proxy->serverflags("-groups ffdhe2048");
118} else {
119    $proxy->serverflags("-groups P-256");
120}
121if (disabled("ec")) {
122    $proxy->clientflags("-groups ffdhe3072");
123} else {
124    $proxy->clientflags("-groups P-384");
125}
126$proxy->start();
127ok(TLSProxy::Message->fail(), "No acceptable key_shares");
128
129#Test 6: A non preferred but acceptable key_share should succeed
130$proxy->clear();
131$proxy->clientflags("-curves P-256");
132if (disabled("ec")) {
133    $proxy->clientflags("-groups ffdhe3072");
134} else {
135    $proxy->clientflags("-groups P-256");
136}
137$proxy->start();
138ok(TLSProxy::Message->success(), "Non preferred key_share");
139$proxy->filter(\&modify_key_shares_filter);
140
141SKIP: {
142    skip "No ec support in this OpenSSL build", 1 if disabled("ec");
143
144    #Test 7: An acceptable key_share after a list of non-acceptable ones should
145    #succeed
146    $proxy->clear();
147    $testtype = ACCEPTABLE_AT_END;
148    $proxy->start();
149    ok(TLSProxy::Message->success(), "Acceptable key_share at end of list");
150}
151
152#Test 8: An acceptable key_share but for a group not in supported_groups should
153#fail
154$proxy->clear();
155$testtype = NOT_IN_SUPPORTED_GROUPS;
156$proxy->start();
157ok(TLSProxy::Message->fail(), "Acceptable key_share not in supported_groups");
158
159#Test 9: Too short group_id should fail
160$proxy->clear();
161$testtype = GROUP_ID_TOO_SHORT;
162$proxy->start();
163ok(TLSProxy::Message->fail(), "Group id too short");
164
165#Test 10: key_exchange length mismatch should fail
166$proxy->clear();
167$testtype = KEX_LEN_MISMATCH;
168$proxy->start();
169ok(TLSProxy::Message->fail(), "key_exchange length mismatch");
170
171#Test 11: Zero length key_exchange should fail
172$proxy->clear();
173$testtype = ZERO_LEN_KEX_DATA;
174$proxy->start();
175ok(TLSProxy::Message->fail(), "zero length key_exchange data");
176
177#Test 12: Trailing data on key_share list should fail
178$proxy->clear();
179$testtype = TRAILING_DATA;
180$proxy->start();
181ok(TLSProxy::Message->fail(), "key_share list trailing data");
182
183#Test 13: Multiple acceptable key_shares - we choose the first one
184$proxy->clear();
185$direction = SERVER_TO_CLIENT;
186$testtype = LOOK_ONLY;
187$selectedgroupid = 0;
188if (disabled("ec")) {
189    $proxy->clientflags("-groups ffdhe3072:ffdhe2048");
190} else {
191    $proxy->clientflags("-groups P-256:X25519");
192}
193$proxy->start();
194if (disabled("ec")) {
195    ok(TLSProxy::Message->success() && ($selectedgroupid == FFDHE3072),
196       "Multiple acceptable key_shares");
197} else {
198    ok(TLSProxy::Message->success() && ($selectedgroupid == P_256),
199       "Multiple acceptable key_shares");
200}
201
202#Test 14: Multiple acceptable key_shares - we choose the first one (part 2)
203$proxy->clear();
204if (disabled("ec")) {
205    $proxy->clientflags("-curves ffdhe2048:ffdhe3072");
206} else {
207    $proxy->clientflags("-curves X25519:P-256");
208}
209$proxy->start();
210if (disabled("ec")) {
211    ok(TLSProxy::Message->success() && ($selectedgroupid == FFDHE2048),
212       "Multiple acceptable key_shares (part 2)");
213} else {
214    ok(TLSProxy::Message->success() && ($selectedgroupid == X25519),
215       "Multiple acceptable key_shares (part 2)");
216}
217
218#Test 15: Server sends key_share that wasn't offered should fail
219$proxy->clear();
220$testtype = SELECT_X25519;
221if (disabled("ec")) {
222    $proxy->clientflags("-groups ffdhe3072");
223} else {
224    $proxy->clientflags("-groups P-256");
225}
226$proxy->start();
227ok(TLSProxy::Message->fail(), "Non offered key_share");
228
229#Test 16: Too short group_id in ServerHello should fail
230$proxy->clear();
231$testtype = GROUP_ID_TOO_SHORT;
232$proxy->start();
233ok(TLSProxy::Message->fail(), "Group id too short in ServerHello");
234
235#Test 17: key_exchange length mismatch in ServerHello should fail
236$proxy->clear();
237$testtype = KEX_LEN_MISMATCH;
238$proxy->start();
239ok(TLSProxy::Message->fail(), "key_exchange length mismatch in ServerHello");
240
241#Test 18: Zero length key_exchange in ServerHello should fail
242$proxy->clear();
243$testtype = ZERO_LEN_KEX_DATA;
244$proxy->start();
245ok(TLSProxy::Message->fail(), "zero length key_exchange data in ServerHello");
246
247#Test 19: Trailing data on key_share in ServerHello should fail
248$proxy->clear();
249$testtype = TRAILING_DATA;
250$proxy->start();
251ok(TLSProxy::Message->fail(), "key_share trailing data in ServerHello");
252
253SKIP: {
254    skip "No TLSv1.2 support in this OpenSSL build", 2 if disabled("tls1_2");
255
256    #Test 20: key_share should not be sent if the client is not capable of
257    #         negotiating TLSv1.3
258    $proxy->clear();
259    $proxy->filter(undef);
260    $proxy->clientflags("-no_tls1_3");
261    $proxy->start();
262    my $clienthello = $proxy->message_list->[0];
263    ok(TLSProxy::Message->success()
264       && !defined $clienthello->extension_data->{TLSProxy::Message::EXT_KEY_SHARE},
265       "No key_share for TLS<=1.2 client");
266    $proxy->filter(\&modify_key_shares_filter);
267
268    #Test 21: A server not capable of negotiating TLSv1.3 should not attempt to
269    #         process a key_share
270    $proxy->clear();
271    $direction = CLIENT_TO_SERVER;
272    $testtype = NO_ACCEPTABLE_KEY_SHARES;
273    $proxy->serverflags("-no_tls1_3");
274    $proxy->start();
275    ok(TLSProxy::Message->success(), "Ignore key_share for TLS<=1.2 server");
276}
277
278#Test 22: The server sending an HRR but not requesting a new key_share should
279#         fail
280$proxy->clear();
281$direction = SERVER_TO_CLIENT;
282$testtype = NO_KEY_SHARES_IN_HRR;
283if (disabled("ec")) {
284    $proxy->serverflags("-groups ffdhe2048");
285} else {
286    $proxy->serverflags("-groups X25519");
287}
288$proxy->start();
289ok(TLSProxy::Message->fail(), "Server sends HRR with no key_shares");
290
291sub modify_key_shares_filter
292{
293    my $proxy = shift;
294
295    # We're only interested in the initial ClientHello
296    if (($direction == CLIENT_TO_SERVER && $proxy->flight != 0
297                && ($proxy->flight != 1 || $testtype != NO_KEY_SHARES_IN_HRR))
298            || ($direction == SERVER_TO_CLIENT && $proxy->flight != 1)) {
299        return;
300    }
301
302    foreach my $message (@{$proxy->message_list}) {
303        if ($message->mt == TLSProxy::Message::MT_CLIENT_HELLO
304                && $direction == CLIENT_TO_SERVER) {
305            my $ext;
306            my $suppgroups;
307
308            #Setup supported groups to include some unrecognised groups
309            $suppgroups = pack "C8",
310                0x00, 0x06, #List Length
311                0xff, 0xfe, #Non existing group 1
312                0xff, 0xff, #Non existing group 2
313                0x00, 0x1d; #x25519
314
315            if ($testtype == EMPTY_EXTENSION) {
316                $ext = pack "C2",
317                    0x00, 0x00;
318            } elsif ($testtype == NO_ACCEPTABLE_KEY_SHARES) {
319                $ext = pack "C12",
320                    0x00, 0x0a, #List Length
321                    0xff, 0xfe, #Non existing group 1
322                    0x00, 0x01, 0xff, #key_exchange data
323                    0xff, 0xff, #Non existing group 2
324                    0x00, 0x01, 0xff; #key_exchange data
325            } elsif ($testtype == ACCEPTABLE_AT_END) {
326                $ext = pack "C11H64",
327                    0x00, 0x29, #List Length
328                    0xff, 0xfe, #Non existing group 1
329                    0x00, 0x01, 0xff, #key_exchange data
330                    0x00, 0x1d, #x25519
331                    0x00, 0x20, #key_exchange data length
332                    "155155B95269ED5C87EAA99C2EF5A593".
333                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data
334            } elsif ($testtype == NOT_IN_SUPPORTED_GROUPS) {
335                $suppgroups = pack "C4",
336                    0x00, 0x02, #List Length
337                    0x00, 0xfe; #Non existing group 1
338            } elsif ($testtype == GROUP_ID_TOO_SHORT) {
339                $ext = pack "C6H64C1",
340                    0x00, 0x25, #List Length
341                    0x00, 0x1d, #x25519
342                    0x00, 0x20, #key_exchange data length
343                    "155155B95269ED5C87EAA99C2EF5A593".
344                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data
345                    0x00;       #Group id too short
346            } elsif ($testtype == KEX_LEN_MISMATCH) {
347                $ext = pack "C8",
348                    0x00, 0x06, #List Length
349                    0x00, 0x1d, #x25519
350                    0x00, 0x20, #key_exchange data length
351                    0x15, 0x51; #Only two bytes of data, but length should be 32
352            } elsif ($testtype == ZERO_LEN_KEX_DATA) {
353                $ext = pack "C10H64",
354                    0x00, 0x28, #List Length
355                    0xff, 0xfe, #Non existing group 1
356                    0x00, 0x00, #zero length key_exchange data is invalid
357                    0x00, 0x1d, #x25519
358                    0x00, 0x20, #key_exchange data length
359                    "155155B95269ED5C87EAA99C2EF5A593".
360                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data
361            } elsif ($testtype == TRAILING_DATA) {
362                $ext = pack "C6H64C1",
363                    0x00, 0x24, #List Length
364                    0x00, 0x1d, #x25519
365                    0x00, 0x20, #key_exchange data length
366                    "155155B95269ED5C87EAA99C2EF5A593".
367                    "EDF83495E80380089F831B94D14B1421", #key_exchange data
368                    0x00; #Trailing garbage
369            } elsif ($testtype == NO_KEY_SHARES_IN_HRR) {
370                #We trick the server into thinking we sent a P-256 key_share -
371                #but the client actually sent X25519
372                $ext = pack "C7",
373                    0x00, 0x05, #List Length
374                    0x00, 0x17, #P-256
375                    0x00, 0x01, #key_exchange data length
376                    0xff;       #Dummy key_share data
377            }
378
379            if ($testtype != EMPTY_EXTENSION
380                    && $testtype != NO_KEY_SHARES_IN_HRR) {
381                $message->set_extension(
382                    TLSProxy::Message::EXT_SUPPORTED_GROUPS, $suppgroups);
383            }
384
385            if ($testtype == MISSING_EXTENSION) {
386                $message->delete_extension(
387                    TLSProxy::Message::EXT_KEY_SHARE);
388            } elsif ($testtype != NOT_IN_SUPPORTED_GROUPS) {
389                $message->set_extension(
390                    TLSProxy::Message::EXT_KEY_SHARE, $ext);
391            }
392
393            $message->repack();
394        } elsif ($message->mt == TLSProxy::Message::MT_SERVER_HELLO
395                     && $direction == SERVER_TO_CLIENT) {
396            my $ext;
397            my $key_share =
398                $message->extension_data->{TLSProxy::Message::EXT_KEY_SHARE};
399            $selectedgroupid = unpack("n", $key_share);
400
401            if ($testtype == LOOK_ONLY) {
402                return;
403            }
404            if ($testtype == NO_KEY_SHARES_IN_HRR) {
405                $message->delete_extension(TLSProxy::Message::EXT_KEY_SHARE);
406                $message->set_extension(TLSProxy::Message::EXT_UNKNOWN, "");
407                $message->repack();
408                return;
409            }
410            if ($testtype == SELECT_X25519) {
411                $ext = pack "C4H64",
412                    0x00, 0x1d, #x25519
413                    0x00, 0x20, #key_exchange data length
414                    "155155B95269ED5C87EAA99C2EF5A593".
415                    "EDF83495E80380089F831B94D14B1421";  #key_exchange data
416            } elsif ($testtype == GROUP_ID_TOO_SHORT) {
417                $ext = pack "C1",
418                    0x00;
419            } elsif ($testtype == KEX_LEN_MISMATCH) {
420                $ext = pack "C6",
421                    0x00, 0x1d, #x25519
422                    0x00, 0x20, #key_exchange data length
423                    0x15, 0x51; #Only two bytes of data, but length should be 32
424            } elsif ($testtype == ZERO_LEN_KEX_DATA) {
425                $ext = pack "C4",
426                    0x00, 0x1d, #x25519
427                    0x00, 0x00, #zero length key_exchange data is invalid
428            } elsif ($testtype == TRAILING_DATA) {
429                $ext = pack "C4H64C1",
430                    0x00, 0x1d, #x25519
431                    0x00, 0x20, #key_exchange data length
432                    "155155B95269ED5C87EAA99C2EF5A593".
433                    "EDF83495E80380089F831B94D14B1421", #key_exchange data
434                    0x00; #Trailing garbage
435            }
436            $message->set_extension(TLSProxy::Message::EXT_KEY_SHARE, $ext);
437
438            $message->repack();
439        }
440    }
441}
442
443
444