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source: vbox/trunk/src/libs/openssl-3.1.2/ssl/statem/extensions_cust.c@ 101021

Last change on this file since 101021 was 101021, checked in by vboxsync, 15 months ago

openssl-3.1.2: Applied and adjusted our OpenSSL changes to 3.1.0. bugref:10519
File size: 17.6 KB
Line 
1/*
2 * Copyright 2014-2021 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 */
9
10/* Custom extension utility functions */
11
12#include <openssl/ct.h>
13#include "../ssl_local.h"
14#include "internal/cryptlib.h"
15#include "statem_local.h"
16
17typedef struct {
18 void *add_arg;
19 custom_ext_add_cb add_cb;
20 custom_ext_free_cb free_cb;
21} custom_ext_add_cb_wrap;
22
23typedef struct {
24 void *parse_arg;
25 custom_ext_parse_cb parse_cb;
26} custom_ext_parse_cb_wrap;
27
28/*
29 * Provide thin wrapper callbacks which convert new style arguments to old style
30 */
31static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
32 unsigned int context,
33 const unsigned char **out,
34 size_t *outlen, X509 *x, size_t chainidx,
35 int *al, void *add_arg)
36{
37 custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
38
39 if (add_cb_wrap->add_cb == NULL)
40 return 1;
41
42 return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
43 add_cb_wrap->add_arg);
44}
45
46static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
47 unsigned int context,
48 const unsigned char *out, void *add_arg)
49{
50 custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;
51
52 if (add_cb_wrap->free_cb == NULL)
53 return;
54
55 add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
56}
57
58static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
59 unsigned int context,
60 const unsigned char *in,
61 size_t inlen, X509 *x, size_t chainidx,
62 int *al, void *parse_arg)
63{
64 custom_ext_parse_cb_wrap *parse_cb_wrap =
65 (custom_ext_parse_cb_wrap *)parse_arg;
66
67 if (parse_cb_wrap->parse_cb == NULL)
68 return 1;
69
70 return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
71 parse_cb_wrap->parse_arg);
72}
73
74/*
75 * Find a custom extension from the list. The |role| param is there to
76 * support the legacy API where custom extensions for client and server could
77 * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
78 * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
79 * client, or ENDPOINT_BOTH for either
80 */
81custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
82 ENDPOINT role, unsigned int ext_type,
83 size_t *idx)
84{
85 size_t i;
86 custom_ext_method *meth = exts->meths;
87
88 for (i = 0; i < exts->meths_count; i++, meth++) {
89 if (ext_type == meth->ext_type
90 && (role == ENDPOINT_BOTH || role == meth->role
91 || meth->role == ENDPOINT_BOTH)) {
92 if (idx != NULL)
93 *idx = i;
94 return meth;
95 }
96 }
97 return NULL;
98}
99
100/*
101 * Initialise custom extensions flags to indicate neither sent nor received.
102 */
103void custom_ext_init(custom_ext_methods *exts)
104{
105 size_t i;
106 custom_ext_method *meth = exts->meths;
107
108 for (i = 0; i < exts->meths_count; i++, meth++)
109 meth->ext_flags = 0;
110}
111
112/* Pass received custom extension data to the application for parsing. */
113int custom_ext_parse(SSL *s, unsigned int context, unsigned int ext_type,
114 const unsigned char *ext_data, size_t ext_size, X509 *x,
115 size_t chainidx)
116{
117 int al;
118 custom_ext_methods *exts = &s->cert->custext;
119 custom_ext_method *meth;
120 ENDPOINT role = ENDPOINT_BOTH;
121
122 if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
123 role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
124
125 meth = custom_ext_find(exts, role, ext_type, NULL);
126 /* If not found return success */
127 if (!meth)
128 return 1;
129
130 /* Check if extension is defined for our protocol. If not, skip */
131 if (!extension_is_relevant(s, meth->context, context))
132 return 1;
133
134 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
135 | SSL_EXT_TLS1_3_SERVER_HELLO
136 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
137 /*
138 * If it's ServerHello or EncryptedExtensions we can't have any
139 * extensions not sent in ClientHello.
140 */
141 if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
142 SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_R_BAD_EXTENSION);
143 return 0;
144 }
145 }
146
147 /*
148 * Extensions received in the ClientHello or CertificateRequest are marked
149 * with the SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
150 * extensions in the response messages
151 */
152 if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST))
153 != 0)
154 meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;
155
156 /* If no parse function set return success */
157 if (!meth->parse_cb)
158 return 1;
159
160 if (meth->parse_cb(s, ext_type, context, ext_data, ext_size, x, chainidx,
161 &al, meth->parse_arg) <= 0) {
162 SSLfatal(s, al, SSL_R_BAD_EXTENSION);
163 return 0;
164 }
165
166 return 1;
167}
168
169/*
170 * Request custom extension data from the application and add to the return
171 * buffer.
172 */
173int custom_ext_add(SSL *s, int context, WPACKET *pkt, X509 *x, size_t chainidx,
174 int maxversion)
175{
176 custom_ext_methods *exts = &s->cert->custext;
177 custom_ext_method *meth;
178 size_t i;
179 int al;
180
181 for (i = 0; i < exts->meths_count; i++) {
182 const unsigned char *out = NULL;
183 size_t outlen = 0;
184
185 meth = exts->meths + i;
186
187 if (!should_add_extension(s, meth->context, context, maxversion))
188 continue;
189
190 if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
191 | SSL_EXT_TLS1_3_SERVER_HELLO
192 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
193 | SSL_EXT_TLS1_3_CERTIFICATE
194 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
195 /* Only send extensions present in ClientHello/CertificateRequest */
196 if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
197 continue;
198 }
199 /*
200 * We skip it if the callback is absent - except for a ClientHello where
201 * we add an empty extension.
202 */
203 if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
204 continue;
205
206 if (meth->add_cb != NULL) {
207 int cb_retval = meth->add_cb(s, meth->ext_type, context, &out,
208 &outlen, x, chainidx, &al,
209 meth->add_arg);
210
211 if (cb_retval < 0) {
212 SSLfatal(s, al, SSL_R_CALLBACK_FAILED);
213 return 0; /* error */
214 }
215 if (cb_retval == 0)
216 continue; /* skip this extension */
217 }
218
219 if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
220 || !WPACKET_start_sub_packet_u16(pkt)
221 || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
222 || !WPACKET_close(pkt)) {
223 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
224 return 0;
225 }
226 if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
227 /*
228 * We can't send duplicates: code logic should prevent this.
229 */
230 if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
231 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
232 return 0;
233 }
234 /*
235 * Indicate extension has been sent: this is both a sanity check to
236 * ensure we don't send duplicate extensions and indicates that it
237 * is not an error if the extension is present in ServerHello.
238 */
239 meth->ext_flags |= SSL_EXT_FLAG_SENT;
240 }
241 if (meth->free_cb != NULL)
242 meth->free_cb(s, meth->ext_type, context, out, meth->add_arg);
243 }
244 return 1;
245}
246
247/* Copy the flags from src to dst for any extensions that exist in both */
248int custom_exts_copy_flags(custom_ext_methods *dst,
249 const custom_ext_methods *src)
250{
251 size_t i;
252 custom_ext_method *methsrc = src->meths;
253
254 for (i = 0; i < src->meths_count; i++, methsrc++) {
255 custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
256 methsrc->ext_type, NULL);
257
258 if (methdst == NULL)
259 continue;
260
261 methdst->ext_flags = methsrc->ext_flags;
262 }
263
264 return 1;
265}
266
267/* Copy table of custom extensions */
268int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
269{
270 size_t i;
271 int err = 0;
272
273 if (src->meths_count > 0) {
274 dst->meths =
275 OPENSSL_memdup(src->meths,
276 sizeof(*src->meths) * src->meths_count);
277 if (dst->meths == NULL)
278 return 0;
279 dst->meths_count = src->meths_count;
280
281 for (i = 0; i < src->meths_count; i++) {
282 custom_ext_method *methsrc = src->meths + i;
283 custom_ext_method *methdst = dst->meths + i;
284
285 if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
286 continue;
287
288 /*
289 * We have found an old style API wrapper. We need to copy the
290 * arguments too.
291 */
292
293 if (err) {
294 methdst->add_arg = NULL;
295 methdst->parse_arg = NULL;
296 continue;
297 }
298
299 methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
300 sizeof(custom_ext_add_cb_wrap));
301 methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
302 sizeof(custom_ext_parse_cb_wrap));
303
304 if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
305 err = 1;
306 }
307 }
308
309 if (err) {
310 custom_exts_free(dst);
311 return 0;
312 }
313
314 return 1;
315}
316
317void custom_exts_free(custom_ext_methods *exts)
318{
319 size_t i;
320 custom_ext_method *meth;
321
322 for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
323 if (meth->add_cb != custom_ext_add_old_cb_wrap)
324 continue;
325
326 /* Old style API wrapper. Need to free the arguments too */
327 OPENSSL_free(meth->add_arg);
328 OPENSSL_free(meth->parse_arg);
329 }
330 OPENSSL_free(exts->meths);
331}
332
333/* Return true if a client custom extension exists, false otherwise */
334int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
335{
336 return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
337 NULL) != NULL;
338}
339
340static int add_custom_ext_intern(SSL_CTX *ctx, ENDPOINT role,
341 unsigned int ext_type,
342 unsigned int context,
343 SSL_custom_ext_add_cb_ex add_cb,
344 SSL_custom_ext_free_cb_ex free_cb,
345 void *add_arg,
346 SSL_custom_ext_parse_cb_ex parse_cb,
347 void *parse_arg)
348{
349 custom_ext_methods *exts = &ctx->cert->custext;
350 custom_ext_method *meth, *tmp;
351
352 /*
353 * Check application error: if add_cb is not set free_cb will never be
354 * called.
355 */
356 if (add_cb == NULL && free_cb != NULL)
357 return 0;
358
359#ifndef OPENSSL_NO_CT
360 /*
361 * We don't want applications registering callbacks for SCT extensions
362 * whilst simultaneously using the built-in SCT validation features, as
363 * these two things may not play well together.
364 */
365 if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
366 && (context & SSL_EXT_CLIENT_HELLO) != 0
367 && SSL_CTX_ct_is_enabled(ctx))
368 return 0;
369#endif
370
371 /*
372 * Don't add if extension supported internally, but make exception
373 * for extension types that previously were not supported, but now are.
374 */
375 if (SSL_extension_supported(ext_type)
376 && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
377 return 0;
378
379 /* Extension type must fit in 16 bits */
380 if (ext_type > 0xffff)
381 return 0;
382 /* Search for duplicate */
383 if (custom_ext_find(exts, role, ext_type, NULL))
384 return 0;
385 tmp = OPENSSL_realloc(exts->meths,
386 (exts->meths_count + 1) * sizeof(custom_ext_method));
387 if (tmp == NULL)
388 return 0;
389
390 exts->meths = tmp;
391 meth = exts->meths + exts->meths_count;
392 memset(meth, 0, sizeof(*meth));
393 meth->role = role;
394 meth->context = context;
395 meth->parse_cb = parse_cb;
396 meth->add_cb = add_cb;
397 meth->free_cb = free_cb;
398 meth->ext_type = ext_type;
399 meth->add_arg = add_arg;
400 meth->parse_arg = parse_arg;
401 exts->meths_count++;
402 return 1;
403}
404
405static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
406 unsigned int ext_type,
407 unsigned int context,
408 custom_ext_add_cb add_cb,
409 custom_ext_free_cb free_cb,
410 void *add_arg,
411 custom_ext_parse_cb parse_cb, void *parse_arg)
412{
413 custom_ext_add_cb_wrap *add_cb_wrap
414 = OPENSSL_malloc(sizeof(*add_cb_wrap));
415 custom_ext_parse_cb_wrap *parse_cb_wrap
416 = OPENSSL_malloc(sizeof(*parse_cb_wrap));
417 int ret;
418
419 if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
420 OPENSSL_free(add_cb_wrap);
421 OPENSSL_free(parse_cb_wrap);
422 return 0;
423 }
424
425 add_cb_wrap->add_arg = add_arg;
426 add_cb_wrap->add_cb = add_cb;
427 add_cb_wrap->free_cb = free_cb;
428 parse_cb_wrap->parse_arg = parse_arg;
429 parse_cb_wrap->parse_cb = parse_cb;
430
431 ret = add_custom_ext_intern(ctx, role, ext_type,
432 context,
433 custom_ext_add_old_cb_wrap,
434 custom_ext_free_old_cb_wrap,
435 add_cb_wrap,
436 custom_ext_parse_old_cb_wrap,
437 parse_cb_wrap);
438
439 if (!ret) {
440 OPENSSL_free(add_cb_wrap);
441 OPENSSL_free(parse_cb_wrap);
442 }
443
444 return ret;
445}
446
447/* Application level functions to add the old custom extension callbacks */
448int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
449 custom_ext_add_cb add_cb,
450 custom_ext_free_cb free_cb,
451 void *add_arg,
452 custom_ext_parse_cb parse_cb, void *parse_arg)
453{
454 return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
455 SSL_EXT_TLS1_2_AND_BELOW_ONLY
456 | SSL_EXT_CLIENT_HELLO
457 | SSL_EXT_TLS1_2_SERVER_HELLO
458 | SSL_EXT_IGNORE_ON_RESUMPTION,
459 add_cb, free_cb, add_arg, parse_cb, parse_arg);
460}
461
462int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
463 custom_ext_add_cb add_cb,
464 custom_ext_free_cb free_cb,
465 void *add_arg,
466 custom_ext_parse_cb parse_cb, void *parse_arg)
467{
468 return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
469 SSL_EXT_TLS1_2_AND_BELOW_ONLY
470 | SSL_EXT_CLIENT_HELLO
471 | SSL_EXT_TLS1_2_SERVER_HELLO
472 | SSL_EXT_IGNORE_ON_RESUMPTION,
473 add_cb, free_cb, add_arg, parse_cb, parse_arg);
474}
475
476int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
477 unsigned int context,
478 SSL_custom_ext_add_cb_ex add_cb,
479 SSL_custom_ext_free_cb_ex free_cb,
480 void *add_arg,
481 SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
482{
483 return add_custom_ext_intern(ctx, ENDPOINT_BOTH, ext_type, context, add_cb,
484 free_cb, add_arg, parse_cb, parse_arg);
485}
486
487int SSL_extension_supported(unsigned int ext_type)
488{
489 switch (ext_type) {
490 /* Internally supported extensions. */
491 case TLSEXT_TYPE_application_layer_protocol_negotiation:
492 case TLSEXT_TYPE_ec_point_formats:
493 case TLSEXT_TYPE_supported_groups:
494 case TLSEXT_TYPE_key_share:
495#ifndef OPENSSL_NO_NEXTPROTONEG
496 case TLSEXT_TYPE_next_proto_neg:
497#endif
498 case TLSEXT_TYPE_padding:
499 case TLSEXT_TYPE_renegotiate:
500 case TLSEXT_TYPE_max_fragment_length:
501 case TLSEXT_TYPE_server_name:
502 case TLSEXT_TYPE_session_ticket:
503 case TLSEXT_TYPE_signature_algorithms:
504#ifndef OPENSSL_NO_SRP
505 case TLSEXT_TYPE_srp:
506#endif
507#ifndef OPENSSL_NO_OCSP
508 case TLSEXT_TYPE_status_request:
509#endif
510#ifndef OPENSSL_NO_CT
511 case TLSEXT_TYPE_signed_certificate_timestamp:
512#endif
513#ifndef OPENSSL_NO_SRTP
514 case TLSEXT_TYPE_use_srtp:
515#endif
516 case TLSEXT_TYPE_encrypt_then_mac:
517 case TLSEXT_TYPE_supported_versions:
518 case TLSEXT_TYPE_extended_master_secret:
519 case TLSEXT_TYPE_psk_kex_modes:
520 case TLSEXT_TYPE_cookie:
521 case TLSEXT_TYPE_early_data:
522 case TLSEXT_TYPE_certificate_authorities:
523 case TLSEXT_TYPE_psk:
524 case TLSEXT_TYPE_post_handshake_auth:
525 return 1;
526 default:
527 return 0;
528 }
529}
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