xref: /openssl/ssl/statem/extensions_srvr.c (revision 7ed6de99)
1 /*
2  * Copyright 2016-2024 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 #include <openssl/ocsp.h>
11 #include "../ssl_local.h"
12 #include "statem_local.h"
13 #include "internal/cryptlib.h"
14 
15 #define COOKIE_STATE_FORMAT_VERSION     1
16 
17 /*
18  * 2 bytes for packet length, 2 bytes for format version, 2 bytes for
19  * protocol version, 2 bytes for group id, 2 bytes for cipher id, 1 byte for
20  * key_share present flag, 8 bytes for timestamp, 2 bytes for the hashlen,
21  * EVP_MAX_MD_SIZE for transcript hash, 1 byte for app cookie length, app cookie
22  * length bytes, SHA256_DIGEST_LENGTH bytes for the HMAC of the whole thing.
23  */
24 #define MAX_COOKIE_SIZE (2 + 2 + 2 + 2 + 2 + 1 + 8 + 2 + EVP_MAX_MD_SIZE + 1 \
25                          + SSL_COOKIE_LENGTH + SHA256_DIGEST_LENGTH)
26 
27 /*
28  * Message header + 2 bytes for protocol version + number of random bytes +
29  * + 1 byte for legacy session id length + number of bytes in legacy session id
30  * + 2 bytes for ciphersuite + 1 byte for legacy compression
31  * + 2 bytes for extension block length + 6 bytes for key_share extension
32  * + 4 bytes for cookie extension header + the number of bytes in the cookie
33  */
34 #define MAX_HRR_SIZE    (SSL3_HM_HEADER_LENGTH + 2 + SSL3_RANDOM_SIZE + 1 \
35                          + SSL_MAX_SSL_SESSION_ID_LENGTH + 2 + 1 + 2 + 6 + 4 \
36                          + MAX_COOKIE_SIZE)
37 
38 /*
39  * Parse the client's renegotiation binding and abort if it's not right
40  */
tls_parse_ctos_renegotiate(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)41 int tls_parse_ctos_renegotiate(SSL_CONNECTION *s, PACKET *pkt,
42                                unsigned int context,
43                                X509 *x, size_t chainidx)
44 {
45     unsigned int ilen;
46     const unsigned char *data;
47     int ok;
48 
49     /* Parse the length byte */
50     if (!PACKET_get_1(pkt, &ilen)
51         || !PACKET_get_bytes(pkt, &data, ilen)) {
52         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_RENEGOTIATION_ENCODING_ERR);
53         return 0;
54     }
55 
56     /* Check that the extension matches */
57     if (ilen != s->s3.previous_client_finished_len) {
58         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_RENEGOTIATION_MISMATCH);
59         return 0;
60     }
61 
62     ok = memcmp(data, s->s3.previous_client_finished,
63                     s->s3.previous_client_finished_len);
64 #ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
65     if (ok) {
66         if ((data[0] ^ s->s3.previous_client_finished[0]) != 0xFF) {
67             ok = 0;
68         }
69     }
70 #endif
71     if (ok) {
72         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_R_RENEGOTIATION_MISMATCH);
73         return 0;
74     }
75 
76     s->s3.send_connection_binding = 1;
77 
78     return 1;
79 }
80 
81 /*-
82  * The servername extension is treated as follows:
83  *
84  * - Only the hostname type is supported with a maximum length of 255.
85  * - The servername is rejected if too long or if it contains zeros,
86  *   in which case an fatal alert is generated.
87  * - The servername field is maintained together with the session cache.
88  * - When a session is resumed, the servername call back invoked in order
89  *   to allow the application to position itself to the right context.
90  * - The servername is acknowledged if it is new for a session or when
91  *   it is identical to a previously used for the same session.
92  *   Applications can control the behaviour.  They can at any time
93  *   set a 'desirable' servername for a new SSL object. This can be the
94  *   case for example with HTTPS when a Host: header field is received and
95  *   a renegotiation is requested. In this case, a possible servername
96  *   presented in the new client hello is only acknowledged if it matches
97  *   the value of the Host: field.
98  * - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
99  *   if they provide for changing an explicit servername context for the
100  *   session, i.e. when the session has been established with a servername
101  *   extension.
102  * - On session reconnect, the servername extension may be absent.
103  */
tls_parse_ctos_server_name(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)104 int tls_parse_ctos_server_name(SSL_CONNECTION *s, PACKET *pkt,
105                                unsigned int context, X509 *x, size_t chainidx)
106 {
107     unsigned int servname_type;
108     PACKET sni, hostname;
109 
110     if (!PACKET_as_length_prefixed_2(pkt, &sni)
111         /* ServerNameList must be at least 1 byte long. */
112         || PACKET_remaining(&sni) == 0) {
113         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
114         return 0;
115     }
116 
117     /*
118      * Although the intent was for server_name to be extensible, RFC 4366
119      * was not clear about it; and so OpenSSL among other implementations,
120      * always and only allows a 'host_name' name types.
121      * RFC 6066 corrected the mistake but adding new name types
122      * is nevertheless no longer feasible, so act as if no other
123      * SNI types can exist, to simplify parsing.
124      *
125      * Also note that the RFC permits only one SNI value per type,
126      * i.e., we can only have a single hostname.
127      */
128     if (!PACKET_get_1(&sni, &servname_type)
129         || servname_type != TLSEXT_NAMETYPE_host_name
130         || !PACKET_as_length_prefixed_2(&sni, &hostname)) {
131         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
132         return 0;
133     }
134 
135     /*
136      * In TLSv1.2 and below the SNI is associated with the session. In TLSv1.3
137      * we always use the SNI value from the handshake.
138      */
139     if (!s->hit || SSL_CONNECTION_IS_TLS13(s)) {
140         if (PACKET_remaining(&hostname) > TLSEXT_MAXLEN_host_name) {
141             SSLfatal(s, SSL_AD_UNRECOGNIZED_NAME, SSL_R_BAD_EXTENSION);
142             return 0;
143         }
144 
145         if (PACKET_contains_zero_byte(&hostname)) {
146             SSLfatal(s, SSL_AD_UNRECOGNIZED_NAME, SSL_R_BAD_EXTENSION);
147             return 0;
148         }
149 
150         /*
151          * Store the requested SNI in the SSL as temporary storage.
152          * If we accept it, it will get stored in the SSL_SESSION as well.
153          */
154         OPENSSL_free(s->ext.hostname);
155         s->ext.hostname = NULL;
156         if (!PACKET_strndup(&hostname, &s->ext.hostname)) {
157             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
158             return 0;
159         }
160 
161         s->servername_done = 1;
162     } else {
163         /*
164          * In TLSv1.2 and below we should check if the SNI is consistent between
165          * the initial handshake and the resumption. In TLSv1.3 SNI is not
166          * associated with the session.
167          */
168         s->servername_done = (s->session->ext.hostname != NULL)
169             && PACKET_equal(&hostname, s->session->ext.hostname,
170                             strlen(s->session->ext.hostname));
171     }
172 
173     return 1;
174 }
175 
tls_parse_ctos_maxfragmentlen(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)176 int tls_parse_ctos_maxfragmentlen(SSL_CONNECTION *s, PACKET *pkt,
177                                   unsigned int context,
178                                   X509 *x, size_t chainidx)
179 {
180     unsigned int value;
181 
182     if (PACKET_remaining(pkt) != 1 || !PACKET_get_1(pkt, &value)) {
183         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
184         return 0;
185     }
186 
187     /* Received |value| should be a valid max-fragment-length code. */
188     if (!IS_MAX_FRAGMENT_LENGTH_EXT_VALID(value)) {
189         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
190                  SSL_R_SSL3_EXT_INVALID_MAX_FRAGMENT_LENGTH);
191         return 0;
192     }
193 
194     /*
195      * When doing a full handshake or a renegotiation max_fragment_len_mode will
196      * be TLSEXT_max_fragment_length_UNSPECIFIED
197      *
198      * In case of a resumption max_fragment_len_mode will be one of
199      *      TLSEXT_max_fragment_length_DISABLED, TLSEXT_max_fragment_length_512,
200      *      TLSEXT_max_fragment_length_1024, TLSEXT_max_fragment_length_2048.
201      *      TLSEXT_max_fragment_length_4096
202      *
203      * RFC 6066: The negotiated length applies for the duration of the session
204      * including session resumptions.
205      *
206      * So we only set the value in case it is unspecified.
207      */
208     if (s->session->ext.max_fragment_len_mode == TLSEXT_max_fragment_length_UNSPECIFIED)
209         /*
210          * Store it in session, so it'll become binding for us
211          * and we'll include it in a next Server Hello.
212          */
213         s->session->ext.max_fragment_len_mode = value;
214 
215     return 1;
216 }
217 
218 #ifndef OPENSSL_NO_SRP
tls_parse_ctos_srp(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)219 int tls_parse_ctos_srp(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
220                        X509 *x, size_t chainidx)
221 {
222     PACKET srp_I;
223 
224     if (!PACKET_as_length_prefixed_1(pkt, &srp_I)
225             || PACKET_contains_zero_byte(&srp_I)) {
226         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
227         return 0;
228     }
229 
230     if (!PACKET_strndup(&srp_I, &s->srp_ctx.login)) {
231         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
232         return 0;
233     }
234 
235     return 1;
236 }
237 #endif
238 
tls_parse_ctos_ec_pt_formats(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)239 int tls_parse_ctos_ec_pt_formats(SSL_CONNECTION *s, PACKET *pkt,
240                                  unsigned int context,
241                                  X509 *x, size_t chainidx)
242 {
243     PACKET ec_point_format_list;
244 
245     if (!PACKET_as_length_prefixed_1(pkt, &ec_point_format_list)
246         || PACKET_remaining(&ec_point_format_list) == 0) {
247         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
248         return 0;
249     }
250 
251     if (!s->hit) {
252         if (!PACKET_memdup(&ec_point_format_list,
253                            &s->ext.peer_ecpointformats,
254                            &s->ext.peer_ecpointformats_len)) {
255             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
256             return 0;
257         }
258     }
259 
260     return 1;
261 }
262 
tls_parse_ctos_session_ticket(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)263 int tls_parse_ctos_session_ticket(SSL_CONNECTION *s, PACKET *pkt,
264                                   unsigned int context,
265                                   X509 *x, size_t chainidx)
266 {
267     if (s->ext.session_ticket_cb &&
268             !s->ext.session_ticket_cb(SSL_CONNECTION_GET_SSL(s),
269                                       PACKET_data(pkt), PACKET_remaining(pkt),
270                                       s->ext.session_ticket_cb_arg)) {
271         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
272         return 0;
273     }
274 
275     return 1;
276 }
277 
tls_parse_ctos_sig_algs_cert(SSL_CONNECTION * s,PACKET * pkt,ossl_unused unsigned int context,ossl_unused X509 * x,ossl_unused size_t chainidx)278 int tls_parse_ctos_sig_algs_cert(SSL_CONNECTION *s, PACKET *pkt,
279                                  ossl_unused unsigned int context,
280                                  ossl_unused X509 *x,
281                                  ossl_unused size_t chainidx)
282 {
283     PACKET supported_sig_algs;
284 
285     if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
286             || PACKET_remaining(&supported_sig_algs) == 0) {
287         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
288         return 0;
289     }
290 
291     if (!s->hit && !tls1_save_sigalgs(s, &supported_sig_algs, 1)) {
292         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
293         return 0;
294     }
295 
296     return 1;
297 }
298 
tls_parse_ctos_sig_algs(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)299 int tls_parse_ctos_sig_algs(SSL_CONNECTION *s, PACKET *pkt,
300                             unsigned int context, X509 *x, size_t chainidx)
301 {
302     PACKET supported_sig_algs;
303 
304     if (!PACKET_as_length_prefixed_2(pkt, &supported_sig_algs)
305             || PACKET_remaining(&supported_sig_algs) == 0) {
306         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
307         return 0;
308     }
309 
310     if (!s->hit && !tls1_save_sigalgs(s, &supported_sig_algs, 0)) {
311         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
312         return 0;
313     }
314 
315     return 1;
316 }
317 
318 #ifndef OPENSSL_NO_OCSP
tls_parse_ctos_status_request(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)319 int tls_parse_ctos_status_request(SSL_CONNECTION *s, PACKET *pkt,
320                                   unsigned int context,
321                                   X509 *x, size_t chainidx)
322 {
323     PACKET responder_id_list, exts;
324 
325     /* We ignore this in a resumption handshake */
326     if (s->hit)
327         return 1;
328 
329     /* Not defined if we get one of these in a client Certificate */
330     if (x != NULL)
331         return 1;
332 
333     if (!PACKET_get_1(pkt, (unsigned int *)&s->ext.status_type)) {
334         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
335         return 0;
336     }
337 
338     if (s->ext.status_type != TLSEXT_STATUSTYPE_ocsp) {
339         /*
340          * We don't know what to do with any other type so ignore it.
341          */
342         s->ext.status_type = TLSEXT_STATUSTYPE_nothing;
343         return 1;
344     }
345 
346     if (!PACKET_get_length_prefixed_2 (pkt, &responder_id_list)) {
347         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
348         return 0;
349     }
350 
351     /*
352      * We remove any OCSP_RESPIDs from a previous handshake
353      * to prevent unbounded memory growth - CVE-2016-6304
354      */
355     sk_OCSP_RESPID_pop_free(s->ext.ocsp.ids, OCSP_RESPID_free);
356     if (PACKET_remaining(&responder_id_list) > 0) {
357         s->ext.ocsp.ids = sk_OCSP_RESPID_new_null();
358         if (s->ext.ocsp.ids == NULL) {
359             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_CRYPTO_LIB);
360             return 0;
361         }
362     } else {
363         s->ext.ocsp.ids = NULL;
364     }
365 
366     while (PACKET_remaining(&responder_id_list) > 0) {
367         OCSP_RESPID *id;
368         PACKET responder_id;
369         const unsigned char *id_data;
370 
371         if (!PACKET_get_length_prefixed_2(&responder_id_list, &responder_id)
372                 || PACKET_remaining(&responder_id) == 0) {
373             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
374             return 0;
375         }
376 
377         id_data = PACKET_data(&responder_id);
378         id = d2i_OCSP_RESPID(NULL, &id_data,
379                              (int)PACKET_remaining(&responder_id));
380         if (id == NULL) {
381             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
382             return 0;
383         }
384 
385         if (id_data != PACKET_end(&responder_id)) {
386             OCSP_RESPID_free(id);
387             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
388 
389             return 0;
390         }
391 
392         if (!sk_OCSP_RESPID_push(s->ext.ocsp.ids, id)) {
393             OCSP_RESPID_free(id);
394             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
395 
396             return 0;
397         }
398     }
399 
400     /* Read in request_extensions */
401     if (!PACKET_as_length_prefixed_2(pkt, &exts)) {
402         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
403         return 0;
404     }
405 
406     if (PACKET_remaining(&exts) > 0) {
407         const unsigned char *ext_data = PACKET_data(&exts);
408 
409         sk_X509_EXTENSION_pop_free(s->ext.ocsp.exts,
410                                    X509_EXTENSION_free);
411         s->ext.ocsp.exts =
412             d2i_X509_EXTENSIONS(NULL, &ext_data, (int)PACKET_remaining(&exts));
413         if (s->ext.ocsp.exts == NULL || ext_data != PACKET_end(&exts)) {
414             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
415             return 0;
416         }
417     }
418 
419     return 1;
420 }
421 #endif
422 
423 #ifndef OPENSSL_NO_NEXTPROTONEG
tls_parse_ctos_npn(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)424 int tls_parse_ctos_npn(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
425                        X509 *x, size_t chainidx)
426 {
427     /*
428      * We shouldn't accept this extension on a
429      * renegotiation.
430      */
431     if (SSL_IS_FIRST_HANDSHAKE(s))
432         s->s3.npn_seen = 1;
433 
434     return 1;
435 }
436 #endif
437 
438 /*
439  * Save the ALPN extension in a ClientHello.|pkt| holds the contents of the ALPN
440  * extension, not including type and length. Returns: 1 on success, 0 on error.
441  */
tls_parse_ctos_alpn(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)442 int tls_parse_ctos_alpn(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
443                         X509 *x, size_t chainidx)
444 {
445     PACKET protocol_list, save_protocol_list, protocol;
446 
447     if (!SSL_IS_FIRST_HANDSHAKE(s))
448         return 1;
449 
450     if (!PACKET_as_length_prefixed_2(pkt, &protocol_list)
451         || PACKET_remaining(&protocol_list) < 2) {
452         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
453         return 0;
454     }
455 
456     save_protocol_list = protocol_list;
457     do {
458         /* Protocol names can't be empty. */
459         if (!PACKET_get_length_prefixed_1(&protocol_list, &protocol)
460                 || PACKET_remaining(&protocol) == 0) {
461             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
462             return 0;
463         }
464     } while (PACKET_remaining(&protocol_list) != 0);
465 
466     OPENSSL_free(s->s3.alpn_proposed);
467     s->s3.alpn_proposed = NULL;
468     s->s3.alpn_proposed_len = 0;
469     if (!PACKET_memdup(&save_protocol_list,
470                        &s->s3.alpn_proposed, &s->s3.alpn_proposed_len)) {
471         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
472         return 0;
473     }
474 
475     return 1;
476 }
477 
478 #ifndef OPENSSL_NO_SRTP
tls_parse_ctos_use_srtp(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)479 int tls_parse_ctos_use_srtp(SSL_CONNECTION *s, PACKET *pkt,
480                             unsigned int context, X509 *x, size_t chainidx)
481 {
482     STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
483     unsigned int ct, mki_len, id;
484     int i, srtp_pref;
485     PACKET subpkt;
486     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
487 
488     /* Ignore this if we have no SRTP profiles */
489     if (SSL_get_srtp_profiles(ssl) == NULL)
490         return 1;
491 
492     /* Pull off the length of the cipher suite list  and check it is even */
493     if (!PACKET_get_net_2(pkt, &ct) || (ct & 1) != 0
494             || !PACKET_get_sub_packet(pkt, &subpkt, ct)) {
495         SSLfatal(s, SSL_AD_DECODE_ERROR,
496                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
497         return 0;
498     }
499 
500     srvr = SSL_get_srtp_profiles(ssl);
501     s->srtp_profile = NULL;
502     /* Search all profiles for a match initially */
503     srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
504 
505     while (PACKET_remaining(&subpkt)) {
506         if (!PACKET_get_net_2(&subpkt, &id)) {
507             SSLfatal(s, SSL_AD_DECODE_ERROR,
508                      SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
509             return 0;
510         }
511 
512         /*
513          * Only look for match in profiles of higher preference than
514          * current match.
515          * If no profiles have been have been configured then this
516          * does nothing.
517          */
518         for (i = 0; i < srtp_pref; i++) {
519             SRTP_PROTECTION_PROFILE *sprof =
520                 sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
521 
522             if (sprof->id == id) {
523                 s->srtp_profile = sprof;
524                 srtp_pref = i;
525                 break;
526             }
527         }
528     }
529 
530     /* Now extract the MKI value as a sanity check, but discard it for now */
531     if (!PACKET_get_1(pkt, &mki_len)) {
532         SSLfatal(s, SSL_AD_DECODE_ERROR,
533                  SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
534         return 0;
535     }
536 
537     if (!PACKET_forward(pkt, mki_len)
538         || PACKET_remaining(pkt)) {
539         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_SRTP_MKI_VALUE);
540         return 0;
541     }
542 
543     return 1;
544 }
545 #endif
546 
tls_parse_ctos_etm(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)547 int tls_parse_ctos_etm(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
548                        X509 *x, size_t chainidx)
549 {
550     if (!(s->options & SSL_OP_NO_ENCRYPT_THEN_MAC))
551         s->ext.use_etm = 1;
552 
553     return 1;
554 }
555 
556 /*
557  * Process a psk_kex_modes extension received in the ClientHello. |pkt| contains
558  * the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
559  */
tls_parse_ctos_psk_kex_modes(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)560 int tls_parse_ctos_psk_kex_modes(SSL_CONNECTION *s, PACKET *pkt,
561                                  unsigned int context,
562                                  X509 *x, size_t chainidx)
563 {
564 #ifndef OPENSSL_NO_TLS1_3
565     PACKET psk_kex_modes;
566     unsigned int mode;
567 
568     if (!PACKET_as_length_prefixed_1(pkt, &psk_kex_modes)
569             || PACKET_remaining(&psk_kex_modes) == 0) {
570         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
571         return 0;
572     }
573 
574     while (PACKET_get_1(&psk_kex_modes, &mode)) {
575         if (mode == TLSEXT_KEX_MODE_KE_DHE)
576             s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE_DHE;
577         else if (mode == TLSEXT_KEX_MODE_KE
578                 && (s->options & SSL_OP_ALLOW_NO_DHE_KEX) != 0)
579             s->ext.psk_kex_mode |= TLSEXT_KEX_MODE_FLAG_KE;
580     }
581 
582     if (((s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) != 0)
583             && (s->options & SSL_OP_PREFER_NO_DHE_KEX) != 0) {
584 
585         /*
586          * If NO_DHE is supported and preferred, then we only remember this
587          * mode. DHE PSK will not be used for sure, because in any case where
588          * it would be supported (i.e. if a key share is present), NO_DHE would
589          * be supported as well. As the latter is preferred it would be
590          * chosen. By removing DHE PSK here, we don't have to deal with the
591          * SSL_OP_PREFER_NO_DHE_KEX option in any other place.
592          */
593         s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_KE;
594     }
595 
596 #endif
597 
598     return 1;
599 }
600 
601 /*
602  * Process a key_share extension received in the ClientHello. |pkt| contains
603  * the raw PACKET data for the extension. Returns 1 on success or 0 on failure.
604  */
tls_parse_ctos_key_share(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)605 int tls_parse_ctos_key_share(SSL_CONNECTION *s, PACKET *pkt,
606                              unsigned int context, X509 *x, size_t chainidx)
607 {
608 #ifndef OPENSSL_NO_TLS1_3
609     unsigned int group_id;
610     PACKET key_share_list, encoded_pt;
611     const uint16_t *clntgroups, *srvrgroups;
612     size_t clnt_num_groups, srvr_num_groups;
613     int found = 0;
614 
615     if (s->hit && (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE) == 0)
616         return 1;
617 
618     /* Sanity check */
619     if (s->s3.peer_tmp != NULL) {
620         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
621         return 0;
622     }
623 
624     if (!PACKET_as_length_prefixed_2(pkt, &key_share_list)) {
625         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
626         return 0;
627     }
628 
629     /* Get our list of supported groups */
630     tls1_get_supported_groups(s, &srvrgroups, &srvr_num_groups);
631     /* Get the clients list of supported groups. */
632     tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups);
633     if (clnt_num_groups == 0) {
634         /*
635          * This can only happen if the supported_groups extension was not sent,
636          * because we verify that the length is non-zero when we process that
637          * extension.
638          */
639         SSLfatal(s, SSL_AD_MISSING_EXTENSION,
640                  SSL_R_MISSING_SUPPORTED_GROUPS_EXTENSION);
641         return 0;
642     }
643 
644     if (s->s3.group_id != 0 && PACKET_remaining(&key_share_list) == 0) {
645         /*
646          * If we set a group_id already, then we must have sent an HRR
647          * requesting a new key_share. If we haven't got one then that is an
648          * error
649          */
650         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_KEY_SHARE);
651         return 0;
652     }
653 
654     while (PACKET_remaining(&key_share_list) > 0) {
655         if (!PACKET_get_net_2(&key_share_list, &group_id)
656                 || !PACKET_get_length_prefixed_2(&key_share_list, &encoded_pt)
657                 || PACKET_remaining(&encoded_pt) == 0) {
658             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
659             return 0;
660         }
661 
662         /*
663          * If we already found a suitable key_share we loop through the
664          * rest to verify the structure, but don't process them.
665          */
666         if (found)
667             continue;
668 
669         /*
670          * If we sent an HRR then the key_share sent back MUST be for the group
671          * we requested, and must be the only key_share sent.
672          */
673         if (s->s3.group_id != 0
674                 && (group_id != s->s3.group_id
675                     || PACKET_remaining(&key_share_list) != 0)) {
676             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_KEY_SHARE);
677             return 0;
678         }
679 
680         /* Check if this share is in supported_groups sent from client */
681         if (!check_in_list(s, group_id, clntgroups, clnt_num_groups, 0)) {
682             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_KEY_SHARE);
683             return 0;
684         }
685 
686         /* Check if this share is for a group we can use */
687         if (!check_in_list(s, group_id, srvrgroups, srvr_num_groups, 1)
688                 || !tls_group_allowed(s, group_id, SSL_SECOP_CURVE_SUPPORTED)
689                    /*
690                     * We tolerate but ignore a group id that we don't think is
691                     * suitable for TLSv1.3
692                     */
693                 || !tls_valid_group(s, group_id, TLS1_3_VERSION, TLS1_3_VERSION,
694                                     0, NULL)) {
695             /* Share not suitable */
696             continue;
697         }
698 
699         s->s3.group_id = group_id;
700         /* Cache the selected group ID in the SSL_SESSION */
701         s->session->kex_group = group_id;
702 
703         if ((s->s3.peer_tmp = ssl_generate_param_group(s, group_id)) == NULL) {
704             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
705                    SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
706             return 0;
707         }
708 
709         if (tls13_set_encoded_pub_key(s->s3.peer_tmp,
710                                       PACKET_data(&encoded_pt),
711                                       PACKET_remaining(&encoded_pt)) <= 0) {
712             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_ECPOINT);
713             return 0;
714         }
715 
716         found = 1;
717     }
718 #endif
719 
720     return 1;
721 }
722 
tls_parse_ctos_cookie(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)723 int tls_parse_ctos_cookie(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
724                           X509 *x, size_t chainidx)
725 {
726 #ifndef OPENSSL_NO_TLS1_3
727     unsigned int format, version, key_share, group_id;
728     EVP_MD_CTX *hctx;
729     EVP_PKEY *pkey;
730     PACKET cookie, raw, chhash, appcookie;
731     WPACKET hrrpkt;
732     const unsigned char *data, *mdin, *ciphdata;
733     unsigned char hmac[SHA256_DIGEST_LENGTH];
734     unsigned char hrr[MAX_HRR_SIZE];
735     size_t rawlen, hmaclen, hrrlen, ciphlen;
736     uint64_t tm, now;
737     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
738     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
739 
740     /* Ignore any cookie if we're not set up to verify it */
741     if (sctx->verify_stateless_cookie_cb == NULL
742             || (s->s3.flags & TLS1_FLAGS_STATELESS) == 0)
743         return 1;
744 
745     if (!PACKET_as_length_prefixed_2(pkt, &cookie)) {
746         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
747         return 0;
748     }
749 
750     raw = cookie;
751     data = PACKET_data(&raw);
752     rawlen = PACKET_remaining(&raw);
753     if (rawlen < SHA256_DIGEST_LENGTH
754             || !PACKET_forward(&raw, rawlen - SHA256_DIGEST_LENGTH)) {
755         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
756         return 0;
757     }
758     mdin = PACKET_data(&raw);
759 
760     /* Verify the HMAC of the cookie */
761     hctx = EVP_MD_CTX_create();
762     pkey = EVP_PKEY_new_raw_private_key_ex(sctx->libctx, "HMAC",
763                                            sctx->propq,
764                                            s->session_ctx->ext.cookie_hmac_key,
765                                            sizeof(s->session_ctx->ext.cookie_hmac_key));
766     if (hctx == NULL || pkey == NULL) {
767         EVP_MD_CTX_free(hctx);
768         EVP_PKEY_free(pkey);
769         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
770         return 0;
771     }
772 
773     hmaclen = SHA256_DIGEST_LENGTH;
774     if (EVP_DigestSignInit_ex(hctx, NULL, "SHA2-256", sctx->libctx,
775                               sctx->propq, pkey, NULL) <= 0
776             || EVP_DigestSign(hctx, hmac, &hmaclen, data,
777                               rawlen - SHA256_DIGEST_LENGTH) <= 0
778             || hmaclen != SHA256_DIGEST_LENGTH) {
779         EVP_MD_CTX_free(hctx);
780         EVP_PKEY_free(pkey);
781         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
782         return 0;
783     }
784 
785     EVP_MD_CTX_free(hctx);
786     EVP_PKEY_free(pkey);
787 
788     if (CRYPTO_memcmp(hmac, mdin, SHA256_DIGEST_LENGTH) != 0) {
789         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_COOKIE_MISMATCH);
790         return 0;
791     }
792 
793     if (!PACKET_get_net_2(&cookie, &format)) {
794         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
795         return 0;
796     }
797     /* Check the cookie format is something we recognise. Ignore it if not */
798     if (format != COOKIE_STATE_FORMAT_VERSION)
799         return 1;
800 
801     /*
802      * The rest of these checks really shouldn't fail since we have verified the
803      * HMAC above.
804      */
805 
806     /* Check the version number is sane */
807     if (!PACKET_get_net_2(&cookie, &version)) {
808         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
809         return 0;
810     }
811     if (version != TLS1_3_VERSION) {
812         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
813                  SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
814         return 0;
815     }
816 
817     if (!PACKET_get_net_2(&cookie, &group_id)) {
818         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
819         return 0;
820     }
821 
822     ciphdata = PACKET_data(&cookie);
823     if (!PACKET_forward(&cookie, 2)) {
824         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
825         return 0;
826     }
827     if (group_id != s->s3.group_id
828             || s->s3.tmp.new_cipher
829                != ssl_get_cipher_by_char(s, ciphdata, 0)) {
830         /*
831          * We chose a different cipher or group id this time around to what is
832          * in the cookie. Something must have changed.
833          */
834         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_CIPHER);
835         return 0;
836     }
837 
838     if (!PACKET_get_1(&cookie, &key_share)
839             || !PACKET_get_net_8(&cookie, &tm)
840             || !PACKET_get_length_prefixed_2(&cookie, &chhash)
841             || !PACKET_get_length_prefixed_1(&cookie, &appcookie)
842             || PACKET_remaining(&cookie) != SHA256_DIGEST_LENGTH) {
843         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_LENGTH_MISMATCH);
844         return 0;
845     }
846 
847     /* We tolerate a cookie age of up to 10 minutes (= 60 * 10 seconds) */
848     now = time(NULL);
849     if (tm > now || (now - tm) > 600) {
850         /* Cookie is stale. Ignore it */
851         return 1;
852     }
853 
854     /* Verify the app cookie */
855     if (sctx->verify_stateless_cookie_cb(ssl,
856                                          PACKET_data(&appcookie),
857                                          PACKET_remaining(&appcookie)) == 0) {
858         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_COOKIE_MISMATCH);
859         return 0;
860     }
861 
862     /*
863      * Reconstruct the HRR that we would have sent in response to the original
864      * ClientHello so we can add it to the transcript hash.
865      * Note: This won't work with custom HRR extensions
866      */
867     if (!WPACKET_init_static_len(&hrrpkt, hrr, sizeof(hrr), 0)) {
868         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
869         return 0;
870     }
871     if (!WPACKET_put_bytes_u8(&hrrpkt, SSL3_MT_SERVER_HELLO)
872             || !WPACKET_start_sub_packet_u24(&hrrpkt)
873             || !WPACKET_put_bytes_u16(&hrrpkt, TLS1_2_VERSION)
874             || !WPACKET_memcpy(&hrrpkt, hrrrandom, SSL3_RANDOM_SIZE)
875             || !WPACKET_sub_memcpy_u8(&hrrpkt, s->tmp_session_id,
876                                       s->tmp_session_id_len)
877             || !ssl->method->put_cipher_by_char(s->s3.tmp.new_cipher, &hrrpkt,
878                                                 &ciphlen)
879             || !WPACKET_put_bytes_u8(&hrrpkt, 0)
880             || !WPACKET_start_sub_packet_u16(&hrrpkt)) {
881         WPACKET_cleanup(&hrrpkt);
882         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
883         return 0;
884     }
885     if (!WPACKET_put_bytes_u16(&hrrpkt, TLSEXT_TYPE_supported_versions)
886             || !WPACKET_start_sub_packet_u16(&hrrpkt)
887             || !WPACKET_put_bytes_u16(&hrrpkt, s->version)
888             || !WPACKET_close(&hrrpkt)) {
889         WPACKET_cleanup(&hrrpkt);
890         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
891         return 0;
892     }
893     if (key_share) {
894         if (!WPACKET_put_bytes_u16(&hrrpkt, TLSEXT_TYPE_key_share)
895                 || !WPACKET_start_sub_packet_u16(&hrrpkt)
896                 || !WPACKET_put_bytes_u16(&hrrpkt, s->s3.group_id)
897                 || !WPACKET_close(&hrrpkt)) {
898             WPACKET_cleanup(&hrrpkt);
899             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
900             return 0;
901         }
902     }
903     if (!WPACKET_put_bytes_u16(&hrrpkt, TLSEXT_TYPE_cookie)
904             || !WPACKET_start_sub_packet_u16(&hrrpkt)
905             || !WPACKET_sub_memcpy_u16(&hrrpkt, data, rawlen)
906             || !WPACKET_close(&hrrpkt) /* cookie extension */
907             || !WPACKET_close(&hrrpkt) /* extension block */
908             || !WPACKET_close(&hrrpkt) /* message */
909             || !WPACKET_get_total_written(&hrrpkt, &hrrlen)
910             || !WPACKET_finish(&hrrpkt)) {
911         WPACKET_cleanup(&hrrpkt);
912         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
913         return 0;
914     }
915 
916     /* Reconstruct the transcript hash */
917     if (!create_synthetic_message_hash(s, PACKET_data(&chhash),
918                                        PACKET_remaining(&chhash), hrr,
919                                        hrrlen)) {
920         /* SSLfatal() already called */
921         return 0;
922     }
923 
924     /* Act as if this ClientHello came after a HelloRetryRequest */
925     s->hello_retry_request = SSL_HRR_PENDING;
926 
927     s->ext.cookieok = 1;
928 #endif
929 
930     return 1;
931 }
932 
tls_parse_ctos_supported_groups(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)933 int tls_parse_ctos_supported_groups(SSL_CONNECTION *s, PACKET *pkt,
934                                     unsigned int context,
935                                     X509 *x, size_t chainidx)
936 {
937     PACKET supported_groups_list;
938 
939     /* Each group is 2 bytes and we must have at least 1. */
940     if (!PACKET_as_length_prefixed_2(pkt, &supported_groups_list)
941             || PACKET_remaining(&supported_groups_list) == 0
942             || (PACKET_remaining(&supported_groups_list) % 2) != 0) {
943         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
944         return 0;
945     }
946 
947     if (!s->hit || SSL_CONNECTION_IS_TLS13(s)) {
948         OPENSSL_free(s->ext.peer_supportedgroups);
949         s->ext.peer_supportedgroups = NULL;
950         s->ext.peer_supportedgroups_len = 0;
951         if (!tls1_save_u16(&supported_groups_list,
952                            &s->ext.peer_supportedgroups,
953                            &s->ext.peer_supportedgroups_len)) {
954             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
955             return 0;
956         }
957     }
958 
959     return 1;
960 }
961 
tls_parse_ctos_ems(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)962 int tls_parse_ctos_ems(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
963                        X509 *x, size_t chainidx)
964 {
965     /* The extension must always be empty */
966     if (PACKET_remaining(pkt) != 0) {
967         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
968         return 0;
969     }
970 
971     if (s->options & SSL_OP_NO_EXTENDED_MASTER_SECRET)
972         return 1;
973 
974     s->s3.flags |= TLS1_FLAGS_RECEIVED_EXTMS;
975 
976     return 1;
977 }
978 
979 
tls_parse_ctos_early_data(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)980 int tls_parse_ctos_early_data(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
981                               X509 *x, size_t chainidx)
982 {
983     if (PACKET_remaining(pkt) != 0) {
984         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
985         return 0;
986     }
987 
988     if (s->hello_retry_request != SSL_HRR_NONE) {
989         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_EXTENSION);
990         return 0;
991     }
992 
993     return 1;
994 }
995 
tls_get_stateful_ticket(SSL_CONNECTION * s,PACKET * tick,SSL_SESSION ** sess)996 static SSL_TICKET_STATUS tls_get_stateful_ticket(SSL_CONNECTION *s, PACKET *tick,
997                                                  SSL_SESSION **sess)
998 {
999     SSL_SESSION *tmpsess = NULL;
1000 
1001     s->ext.ticket_expected = 1;
1002 
1003     switch (PACKET_remaining(tick)) {
1004         case 0:
1005             return SSL_TICKET_EMPTY;
1006 
1007         case SSL_MAX_SSL_SESSION_ID_LENGTH:
1008             break;
1009 
1010         default:
1011             return SSL_TICKET_NO_DECRYPT;
1012     }
1013 
1014     tmpsess = lookup_sess_in_cache(s, PACKET_data(tick),
1015                                    SSL_MAX_SSL_SESSION_ID_LENGTH);
1016 
1017     if (tmpsess == NULL)
1018         return SSL_TICKET_NO_DECRYPT;
1019 
1020     *sess = tmpsess;
1021     return SSL_TICKET_SUCCESS;
1022 }
1023 
tls_parse_ctos_psk(SSL_CONNECTION * s,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1024 int tls_parse_ctos_psk(SSL_CONNECTION *s, PACKET *pkt, unsigned int context,
1025                        X509 *x, size_t chainidx)
1026 {
1027     PACKET identities, binders, binder;
1028     size_t binderoffset;
1029     int hashsize;
1030     SSL_SESSION *sess = NULL;
1031     unsigned int id, i, ext = 0;
1032     const EVP_MD *md = NULL;
1033     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
1034     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
1035 
1036     /*
1037      * If we have no PSK kex mode that we recognise then we can't resume so
1038      * ignore this extension
1039      */
1040     if ((s->ext.psk_kex_mode
1041             & (TLSEXT_KEX_MODE_FLAG_KE | TLSEXT_KEX_MODE_FLAG_KE_DHE)) == 0)
1042         return 1;
1043 
1044     if (!PACKET_get_length_prefixed_2(pkt, &identities)) {
1045         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1046         return 0;
1047     }
1048 
1049     s->ext.ticket_expected = 0;
1050     for (id = 0; PACKET_remaining(&identities) != 0; id++) {
1051         PACKET identity;
1052         unsigned long ticket_agel;
1053         size_t idlen;
1054 
1055         if (!PACKET_get_length_prefixed_2(&identities, &identity)
1056                 || !PACKET_get_net_4(&identities, &ticket_agel)) {
1057             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1058             return 0;
1059         }
1060 
1061         idlen = PACKET_remaining(&identity);
1062         if (s->psk_find_session_cb != NULL
1063                 && !s->psk_find_session_cb(ssl, PACKET_data(&identity), idlen,
1064                                            &sess)) {
1065             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_BAD_EXTENSION);
1066             return 0;
1067         }
1068 
1069 #ifndef OPENSSL_NO_PSK
1070         if (sess == NULL
1071                 && s->psk_server_callback != NULL
1072                 && idlen <= PSK_MAX_IDENTITY_LEN) {
1073             char *pskid = NULL;
1074             unsigned char pskdata[PSK_MAX_PSK_LEN];
1075             unsigned int pskdatalen;
1076 
1077             if (!PACKET_strndup(&identity, &pskid)) {
1078                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1079                 return 0;
1080             }
1081             pskdatalen = s->psk_server_callback(ssl, pskid, pskdata,
1082                                                 sizeof(pskdata));
1083             OPENSSL_free(pskid);
1084             if (pskdatalen > PSK_MAX_PSK_LEN) {
1085                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1086                 return 0;
1087             } else if (pskdatalen > 0) {
1088                 const SSL_CIPHER *cipher;
1089                 const unsigned char tls13_aes128gcmsha256_id[] = { 0x13, 0x01 };
1090 
1091                 /*
1092                  * We found a PSK using an old style callback. We don't know
1093                  * the digest so we default to SHA256 as per the TLSv1.3 spec
1094                  */
1095                 cipher = SSL_CIPHER_find(ssl, tls13_aes128gcmsha256_id);
1096                 if (cipher == NULL) {
1097                     OPENSSL_cleanse(pskdata, pskdatalen);
1098                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1099                     return 0;
1100                 }
1101 
1102                 sess = SSL_SESSION_new();
1103                 if (sess == NULL
1104                         || !SSL_SESSION_set1_master_key(sess, pskdata,
1105                                                         pskdatalen)
1106                         || !SSL_SESSION_set_cipher(sess, cipher)
1107                         || !SSL_SESSION_set_protocol_version(sess,
1108                                                              TLS1_3_VERSION)) {
1109                     OPENSSL_cleanse(pskdata, pskdatalen);
1110                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1111                     goto err;
1112                 }
1113                 OPENSSL_cleanse(pskdata, pskdatalen);
1114             }
1115         }
1116 #endif /* OPENSSL_NO_PSK */
1117 
1118         if (sess != NULL) {
1119             /* We found a PSK */
1120             SSL_SESSION *sesstmp = ssl_session_dup(sess, 0);
1121 
1122             if (sesstmp == NULL) {
1123                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1124                 return 0;
1125             }
1126             SSL_SESSION_free(sess);
1127             sess = sesstmp;
1128 
1129             /*
1130              * We've just been told to use this session for this context so
1131              * make sure the sid_ctx matches up.
1132              */
1133             memcpy(sess->sid_ctx, s->sid_ctx, s->sid_ctx_length);
1134             sess->sid_ctx_length = s->sid_ctx_length;
1135             ext = 1;
1136             if (id == 0)
1137                 s->ext.early_data_ok = 1;
1138             s->ext.ticket_expected = 1;
1139         } else {
1140             OSSL_TIME t, age, expire;
1141             int ret;
1142 
1143             /*
1144              * If we are using anti-replay protection then we behave as if
1145              * SSL_OP_NO_TICKET is set - we are caching tickets anyway so there
1146              * is no point in using full stateless tickets.
1147              */
1148             if ((s->options & SSL_OP_NO_TICKET) != 0
1149                     || (s->max_early_data > 0
1150                         && (s->options & SSL_OP_NO_ANTI_REPLAY) == 0))
1151                 ret = tls_get_stateful_ticket(s, &identity, &sess);
1152             else
1153                 ret = tls_decrypt_ticket(s, PACKET_data(&identity),
1154                                          PACKET_remaining(&identity), NULL, 0,
1155                                          &sess);
1156 
1157             if (ret == SSL_TICKET_EMPTY) {
1158                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1159                 return 0;
1160             }
1161 
1162             if (ret == SSL_TICKET_FATAL_ERR_MALLOC
1163                     || ret == SSL_TICKET_FATAL_ERR_OTHER) {
1164                 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1165                 return 0;
1166             }
1167             if (ret == SSL_TICKET_NONE || ret == SSL_TICKET_NO_DECRYPT)
1168                 continue;
1169 
1170             /* Check for replay */
1171             if (s->max_early_data > 0
1172                     && (s->options & SSL_OP_NO_ANTI_REPLAY) == 0
1173                     && !SSL_CTX_remove_session(s->session_ctx, sess)) {
1174                 SSL_SESSION_free(sess);
1175                 sess = NULL;
1176                 continue;
1177             }
1178 
1179             age = ossl_time_subtract(ossl_ms2time(ticket_agel),
1180                                      ossl_ms2time(sess->ext.tick_age_add));
1181             t = ossl_time_subtract(ossl_time_now(), sess->time);
1182 
1183             /*
1184              * Although internally we use OSS_TIME which has ns granularity,
1185              * when SSL_SESSION structures are serialised/deserialised we use
1186              * second granularity for the sess->time field. Therefore it could
1187              * appear that the client's ticket age is longer than ours (our
1188              * ticket age calculation should always be slightly longer than the
1189              * client's due to the network latency). Therefore we add 1000ms to
1190              * our age calculation to adjust for rounding errors.
1191              */
1192             expire = ossl_time_add(t, ossl_ms2time(1000));
1193 
1194             if (id == 0
1195                     && ossl_time_compare(sess->timeout, t) >= 0
1196                     && ossl_time_compare(age, expire) <= 0
1197                     && ossl_time_compare(ossl_time_add(age, TICKET_AGE_ALLOWANCE),
1198                                          expire) >= 0) {
1199                 /*
1200                  * Ticket age is within tolerance and not expired. We allow it
1201                  * for early data
1202                  */
1203                 s->ext.early_data_ok = 1;
1204             }
1205         }
1206 
1207         md = ssl_md(sctx, sess->cipher->algorithm2);
1208         if (md == NULL) {
1209             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1210             goto err;
1211         }
1212         if (!EVP_MD_is_a(md,
1213                 EVP_MD_get0_name(ssl_md(sctx,
1214                                         s->s3.tmp.new_cipher->algorithm2)))) {
1215             /* The ciphersuite is not compatible with this session. */
1216             SSL_SESSION_free(sess);
1217             sess = NULL;
1218             s->ext.early_data_ok = 0;
1219             s->ext.ticket_expected = 0;
1220             continue;
1221         }
1222         break;
1223     }
1224 
1225     if (sess == NULL)
1226         return 1;
1227 
1228     binderoffset = PACKET_data(pkt) - (const unsigned char *)s->init_buf->data;
1229     hashsize = EVP_MD_get_size(md);
1230     if (hashsize <= 0)
1231         goto err;
1232 
1233     if (!PACKET_get_length_prefixed_2(pkt, &binders)) {
1234         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1235         goto err;
1236     }
1237 
1238     for (i = 0; i <= id; i++) {
1239         if (!PACKET_get_length_prefixed_1(&binders, &binder)) {
1240             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1241             goto err;
1242         }
1243     }
1244 
1245     if (PACKET_remaining(&binder) != (size_t)hashsize) {
1246         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
1247         goto err;
1248     }
1249     if (tls_psk_do_binder(s, md, (const unsigned char *)s->init_buf->data,
1250                           binderoffset, PACKET_data(&binder), NULL, sess, 0,
1251                           ext) != 1) {
1252         /* SSLfatal() already called */
1253         goto err;
1254     }
1255 
1256     s->ext.tick_identity = id;
1257 
1258     SSL_SESSION_free(s->session);
1259     s->session = sess;
1260     return 1;
1261 err:
1262     SSL_SESSION_free(sess);
1263     return 0;
1264 }
1265 
tls_parse_ctos_post_handshake_auth(SSL_CONNECTION * s,PACKET * pkt,ossl_unused unsigned int context,ossl_unused X509 * x,ossl_unused size_t chainidx)1266 int tls_parse_ctos_post_handshake_auth(SSL_CONNECTION *s, PACKET *pkt,
1267                                        ossl_unused unsigned int context,
1268                                        ossl_unused X509 *x,
1269                                        ossl_unused size_t chainidx)
1270 {
1271     if (PACKET_remaining(pkt) != 0) {
1272         SSLfatal(s, SSL_AD_DECODE_ERROR,
1273                  SSL_R_POST_HANDSHAKE_AUTH_ENCODING_ERR);
1274         return 0;
1275     }
1276 
1277     s->post_handshake_auth = SSL_PHA_EXT_RECEIVED;
1278 
1279     return 1;
1280 }
1281 
1282 /*
1283  * Add the server's renegotiation binding
1284  */
tls_construct_stoc_renegotiate(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1285 EXT_RETURN tls_construct_stoc_renegotiate(SSL_CONNECTION *s, WPACKET *pkt,
1286                                           unsigned int context, X509 *x,
1287                                           size_t chainidx)
1288 {
1289     if (!s->s3.send_connection_binding)
1290         return EXT_RETURN_NOT_SENT;
1291 
1292     /* Still add this even if SSL_OP_NO_RENEGOTIATION is set */
1293     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_renegotiate)
1294             || !WPACKET_start_sub_packet_u16(pkt)
1295             || !WPACKET_start_sub_packet_u8(pkt)
1296             || !WPACKET_memcpy(pkt, s->s3.previous_client_finished,
1297                                s->s3.previous_client_finished_len)
1298             || !WPACKET_memcpy(pkt, s->s3.previous_server_finished,
1299                                s->s3.previous_server_finished_len)
1300             || !WPACKET_close(pkt)
1301             || !WPACKET_close(pkt)) {
1302         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1303         return EXT_RETURN_FAIL;
1304     }
1305 
1306     return EXT_RETURN_SENT;
1307 }
1308 
tls_construct_stoc_server_name(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1309 EXT_RETURN tls_construct_stoc_server_name(SSL_CONNECTION *s, WPACKET *pkt,
1310                                           unsigned int context, X509 *x,
1311                                           size_t chainidx)
1312 {
1313     if (s->servername_done != 1)
1314         return EXT_RETURN_NOT_SENT;
1315 
1316     /*
1317      * Prior to TLSv1.3 we ignore any SNI in the current handshake if resuming.
1318      * We just use the servername from the initial handshake.
1319      */
1320     if (s->hit && !SSL_CONNECTION_IS_TLS13(s))
1321         return EXT_RETURN_NOT_SENT;
1322 
1323     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_server_name)
1324             || !WPACKET_put_bytes_u16(pkt, 0)) {
1325         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1326         return EXT_RETURN_FAIL;
1327     }
1328 
1329     return EXT_RETURN_SENT;
1330 }
1331 
1332 /* Add/include the server's max fragment len extension into ServerHello */
tls_construct_stoc_maxfragmentlen(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1333 EXT_RETURN tls_construct_stoc_maxfragmentlen(SSL_CONNECTION *s, WPACKET *pkt,
1334                                              unsigned int context, X509 *x,
1335                                              size_t chainidx)
1336 {
1337     if (!USE_MAX_FRAGMENT_LENGTH_EXT(s->session))
1338         return EXT_RETURN_NOT_SENT;
1339 
1340     /*-
1341      * 4 bytes for this extension type and extension length
1342      * 1 byte for the Max Fragment Length code value.
1343      */
1344     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_max_fragment_length)
1345         || !WPACKET_start_sub_packet_u16(pkt)
1346         || !WPACKET_put_bytes_u8(pkt, s->session->ext.max_fragment_len_mode)
1347         || !WPACKET_close(pkt)) {
1348         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1349         return EXT_RETURN_FAIL;
1350     }
1351 
1352     return EXT_RETURN_SENT;
1353 }
1354 
tls_construct_stoc_ec_pt_formats(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1355 EXT_RETURN tls_construct_stoc_ec_pt_formats(SSL_CONNECTION *s, WPACKET *pkt,
1356                                             unsigned int context, X509 *x,
1357                                             size_t chainidx)
1358 {
1359     unsigned long alg_k = s->s3.tmp.new_cipher->algorithm_mkey;
1360     unsigned long alg_a = s->s3.tmp.new_cipher->algorithm_auth;
1361     int using_ecc = ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))
1362                     && (s->ext.peer_ecpointformats != NULL);
1363     const unsigned char *plist;
1364     size_t plistlen;
1365 
1366     if (!using_ecc)
1367         return EXT_RETURN_NOT_SENT;
1368 
1369     tls1_get_formatlist(s, &plist, &plistlen);
1370     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_ec_point_formats)
1371             || !WPACKET_start_sub_packet_u16(pkt)
1372             || !WPACKET_sub_memcpy_u8(pkt, plist, plistlen)
1373             || !WPACKET_close(pkt)) {
1374         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1375         return EXT_RETURN_FAIL;
1376     }
1377 
1378     return EXT_RETURN_SENT;
1379 }
1380 
tls_construct_stoc_supported_groups(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1381 EXT_RETURN tls_construct_stoc_supported_groups(SSL_CONNECTION *s, WPACKET *pkt,
1382                                                unsigned int context, X509 *x,
1383                                                size_t chainidx)
1384 {
1385     const uint16_t *groups;
1386     size_t numgroups, i, first = 1;
1387     int version;
1388 
1389     /* s->s3.group_id is non zero if we accepted a key_share */
1390     if (s->s3.group_id == 0)
1391         return EXT_RETURN_NOT_SENT;
1392 
1393     /* Get our list of supported groups */
1394     tls1_get_supported_groups(s, &groups, &numgroups);
1395     if (numgroups == 0) {
1396         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1397         return EXT_RETURN_FAIL;
1398     }
1399 
1400     /* Copy group ID if supported */
1401     version = SSL_version(SSL_CONNECTION_GET_SSL(s));
1402     for (i = 0; i < numgroups; i++) {
1403         uint16_t group = groups[i];
1404 
1405         if (tls_valid_group(s, group, version, version, 0, NULL)
1406                 && tls_group_allowed(s, group, SSL_SECOP_CURVE_SUPPORTED)) {
1407             if (first) {
1408                 /*
1409                  * Check if the client is already using our preferred group. If
1410                  * so we don't need to add this extension
1411                  */
1412                 if (s->s3.group_id == group)
1413                     return EXT_RETURN_NOT_SENT;
1414 
1415                 /* Add extension header */
1416                 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_groups)
1417                            /* Sub-packet for supported_groups extension */
1418                         || !WPACKET_start_sub_packet_u16(pkt)
1419                         || !WPACKET_start_sub_packet_u16(pkt)) {
1420                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1421                     return EXT_RETURN_FAIL;
1422                 }
1423 
1424                 first = 0;
1425             }
1426             if (!WPACKET_put_bytes_u16(pkt, group)) {
1427                     SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1428                     return EXT_RETURN_FAIL;
1429                 }
1430         }
1431     }
1432 
1433     if (!WPACKET_close(pkt) || !WPACKET_close(pkt)) {
1434         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1435         return EXT_RETURN_FAIL;
1436     }
1437 
1438     return EXT_RETURN_SENT;
1439 }
1440 
tls_construct_stoc_session_ticket(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1441 EXT_RETURN tls_construct_stoc_session_ticket(SSL_CONNECTION *s, WPACKET *pkt,
1442                                              unsigned int context, X509 *x,
1443                                              size_t chainidx)
1444 {
1445     if (!s->ext.ticket_expected || !tls_use_ticket(s)) {
1446         s->ext.ticket_expected = 0;
1447         return EXT_RETURN_NOT_SENT;
1448     }
1449 
1450     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_session_ticket)
1451             || !WPACKET_put_bytes_u16(pkt, 0)) {
1452         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1453         return EXT_RETURN_FAIL;
1454     }
1455 
1456     return EXT_RETURN_SENT;
1457 }
1458 
1459 #ifndef OPENSSL_NO_OCSP
tls_construct_stoc_status_request(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1460 EXT_RETURN tls_construct_stoc_status_request(SSL_CONNECTION *s, WPACKET *pkt,
1461                                              unsigned int context, X509 *x,
1462                                              size_t chainidx)
1463 {
1464     /* We don't currently support this extension inside a CertificateRequest */
1465     if (context == SSL_EXT_TLS1_3_CERTIFICATE_REQUEST)
1466         return EXT_RETURN_NOT_SENT;
1467 
1468     if (!s->ext.status_expected)
1469         return EXT_RETURN_NOT_SENT;
1470 
1471     if (SSL_CONNECTION_IS_TLS13(s) && chainidx != 0)
1472         return EXT_RETURN_NOT_SENT;
1473 
1474     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_status_request)
1475             || !WPACKET_start_sub_packet_u16(pkt)) {
1476         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1477         return EXT_RETURN_FAIL;
1478     }
1479 
1480     /*
1481      * In TLSv1.3 we include the certificate status itself. In <= TLSv1.2 we
1482      * send back an empty extension, with the certificate status appearing as a
1483      * separate message
1484      */
1485     if (SSL_CONNECTION_IS_TLS13(s) && !tls_construct_cert_status_body(s, pkt)) {
1486        /* SSLfatal() already called */
1487        return EXT_RETURN_FAIL;
1488     }
1489     if (!WPACKET_close(pkt)) {
1490         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1491         return EXT_RETURN_FAIL;
1492     }
1493 
1494     return EXT_RETURN_SENT;
1495 }
1496 #endif
1497 
1498 #ifndef OPENSSL_NO_NEXTPROTONEG
tls_construct_stoc_next_proto_neg(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1499 EXT_RETURN tls_construct_stoc_next_proto_neg(SSL_CONNECTION *s, WPACKET *pkt,
1500                                              unsigned int context, X509 *x,
1501                                              size_t chainidx)
1502 {
1503     const unsigned char *npa;
1504     unsigned int npalen;
1505     int ret;
1506     int npn_seen = s->s3.npn_seen;
1507     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
1508 
1509     s->s3.npn_seen = 0;
1510     if (!npn_seen || sctx->ext.npn_advertised_cb == NULL)
1511         return EXT_RETURN_NOT_SENT;
1512 
1513     ret = sctx->ext.npn_advertised_cb(SSL_CONNECTION_GET_SSL(s), &npa, &npalen,
1514                                       sctx->ext.npn_advertised_cb_arg);
1515     if (ret == SSL_TLSEXT_ERR_OK) {
1516         if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_next_proto_neg)
1517                 || !WPACKET_sub_memcpy_u16(pkt, npa, npalen)) {
1518             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1519             return EXT_RETURN_FAIL;
1520         }
1521         s->s3.npn_seen = 1;
1522         return EXT_RETURN_SENT;
1523     }
1524 
1525     return EXT_RETURN_NOT_SENT;
1526 }
1527 #endif
1528 
tls_construct_stoc_alpn(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1529 EXT_RETURN tls_construct_stoc_alpn(SSL_CONNECTION *s, WPACKET *pkt, unsigned int context,
1530                                    X509 *x, size_t chainidx)
1531 {
1532     if (s->s3.alpn_selected == NULL)
1533         return EXT_RETURN_NOT_SENT;
1534 
1535     if (!WPACKET_put_bytes_u16(pkt,
1536                 TLSEXT_TYPE_application_layer_protocol_negotiation)
1537             || !WPACKET_start_sub_packet_u16(pkt)
1538             || !WPACKET_start_sub_packet_u16(pkt)
1539             || !WPACKET_sub_memcpy_u8(pkt, s->s3.alpn_selected,
1540                                       s->s3.alpn_selected_len)
1541             || !WPACKET_close(pkt)
1542             || !WPACKET_close(pkt)) {
1543         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1544         return EXT_RETURN_FAIL;
1545     }
1546 
1547     return EXT_RETURN_SENT;
1548 }
1549 
1550 #ifndef OPENSSL_NO_SRTP
tls_construct_stoc_use_srtp(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1551 EXT_RETURN tls_construct_stoc_use_srtp(SSL_CONNECTION *s, WPACKET *pkt,
1552                                        unsigned int context, X509 *x,
1553                                        size_t chainidx)
1554 {
1555     if (s->srtp_profile == NULL)
1556         return EXT_RETURN_NOT_SENT;
1557 
1558     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_use_srtp)
1559             || !WPACKET_start_sub_packet_u16(pkt)
1560             || !WPACKET_put_bytes_u16(pkt, 2)
1561             || !WPACKET_put_bytes_u16(pkt, s->srtp_profile->id)
1562             || !WPACKET_put_bytes_u8(pkt, 0)
1563             || !WPACKET_close(pkt)) {
1564         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1565         return EXT_RETURN_FAIL;
1566     }
1567 
1568     return EXT_RETURN_SENT;
1569 }
1570 #endif
1571 
tls_construct_stoc_etm(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1572 EXT_RETURN tls_construct_stoc_etm(SSL_CONNECTION *s, WPACKET *pkt,
1573                                   unsigned int context,
1574                                   X509 *x, size_t chainidx)
1575 {
1576     if (!s->ext.use_etm)
1577         return EXT_RETURN_NOT_SENT;
1578 
1579     /*
1580      * Don't use encrypt_then_mac if AEAD or RC4 might want to disable
1581      * for other cases too.
1582      */
1583     if (s->s3.tmp.new_cipher->algorithm_mac == SSL_AEAD
1584         || s->s3.tmp.new_cipher->algorithm_enc == SSL_RC4
1585         || s->s3.tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT
1586         || s->s3.tmp.new_cipher->algorithm_enc == SSL_eGOST2814789CNT12
1587         || s->s3.tmp.new_cipher->algorithm_enc == SSL_MAGMA
1588         || s->s3.tmp.new_cipher->algorithm_enc == SSL_KUZNYECHIK) {
1589         s->ext.use_etm = 0;
1590         return EXT_RETURN_NOT_SENT;
1591     }
1592 
1593     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_encrypt_then_mac)
1594             || !WPACKET_put_bytes_u16(pkt, 0)) {
1595         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1596         return EXT_RETURN_FAIL;
1597     }
1598 
1599     return EXT_RETURN_SENT;
1600 }
1601 
tls_construct_stoc_ems(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1602 EXT_RETURN tls_construct_stoc_ems(SSL_CONNECTION *s, WPACKET *pkt,
1603                                   unsigned int context,
1604                                   X509 *x, size_t chainidx)
1605 {
1606     if ((s->s3.flags & TLS1_FLAGS_RECEIVED_EXTMS) == 0)
1607         return EXT_RETURN_NOT_SENT;
1608 
1609     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_extended_master_secret)
1610             || !WPACKET_put_bytes_u16(pkt, 0)) {
1611         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1612         return EXT_RETURN_FAIL;
1613     }
1614 
1615     return EXT_RETURN_SENT;
1616 }
1617 
tls_construct_stoc_supported_versions(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1618 EXT_RETURN tls_construct_stoc_supported_versions(SSL_CONNECTION *s, WPACKET *pkt,
1619                                                  unsigned int context, X509 *x,
1620                                                  size_t chainidx)
1621 {
1622     if (!ossl_assert(SSL_CONNECTION_IS_TLS13(s))) {
1623         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1624         return EXT_RETURN_FAIL;
1625     }
1626 
1627     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_supported_versions)
1628             || !WPACKET_start_sub_packet_u16(pkt)
1629             || !WPACKET_put_bytes_u16(pkt, s->version)
1630             || !WPACKET_close(pkt)) {
1631         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1632         return EXT_RETURN_FAIL;
1633     }
1634 
1635     return EXT_RETURN_SENT;
1636 }
1637 
tls_construct_stoc_key_share(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1638 EXT_RETURN tls_construct_stoc_key_share(SSL_CONNECTION *s, WPACKET *pkt,
1639                                         unsigned int context, X509 *x,
1640                                         size_t chainidx)
1641 {
1642 #ifndef OPENSSL_NO_TLS1_3
1643     unsigned char *encodedPoint;
1644     size_t encoded_pt_len = 0;
1645     EVP_PKEY *ckey = s->s3.peer_tmp, *skey = NULL;
1646     const TLS_GROUP_INFO *ginf = NULL;
1647 
1648     if (s->hello_retry_request == SSL_HRR_PENDING) {
1649         if (ckey != NULL) {
1650             /* Original key_share was acceptable so don't ask for another one */
1651             return EXT_RETURN_NOT_SENT;
1652         }
1653         if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
1654                 || !WPACKET_start_sub_packet_u16(pkt)
1655                 || !WPACKET_put_bytes_u16(pkt, s->s3.group_id)
1656                 || !WPACKET_close(pkt)) {
1657             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1658             return EXT_RETURN_FAIL;
1659         }
1660 
1661         return EXT_RETURN_SENT;
1662     }
1663 
1664     if (ckey == NULL) {
1665         /* No key_share received from client - must be resuming */
1666         if (!s->hit || !tls13_generate_handshake_secret(s, NULL, 0)) {
1667             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1668             return EXT_RETURN_FAIL;
1669         }
1670         return EXT_RETURN_NOT_SENT;
1671     }
1672 
1673     if (s->hit && (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE) == 0) {
1674         /*
1675          * PSK ('hit') and explicitly not doing DHE. If the client sent the
1676          * DHE option, we take it by default, except if non-DHE would be
1677          * preferred by config, but this case would have been handled in
1678          * tls_parse_ctos_psk_kex_modes().
1679          */
1680         return EXT_RETURN_NOT_SENT;
1681     }
1682 
1683     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_key_share)
1684             || !WPACKET_start_sub_packet_u16(pkt)
1685             || !WPACKET_put_bytes_u16(pkt, s->s3.group_id)) {
1686         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1687         return EXT_RETURN_FAIL;
1688     }
1689 
1690     if ((ginf = tls1_group_id_lookup(SSL_CONNECTION_GET_CTX(s),
1691                                      s->s3.group_id)) == NULL) {
1692         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1693         return EXT_RETURN_FAIL;
1694     }
1695 
1696     if (!ginf->is_kem) {
1697         /* Regular KEX */
1698         skey = ssl_generate_pkey(s, ckey);
1699         if (skey == NULL) {
1700             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_SSL_LIB);
1701             return EXT_RETURN_FAIL;
1702         }
1703 
1704         /* Generate encoding of server key */
1705         encoded_pt_len = EVP_PKEY_get1_encoded_public_key(skey, &encodedPoint);
1706         if (encoded_pt_len == 0) {
1707             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EC_LIB);
1708             EVP_PKEY_free(skey);
1709             return EXT_RETURN_FAIL;
1710         }
1711 
1712         if (!WPACKET_sub_memcpy_u16(pkt, encodedPoint, encoded_pt_len)
1713                 || !WPACKET_close(pkt)) {
1714             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1715             EVP_PKEY_free(skey);
1716             OPENSSL_free(encodedPoint);
1717             return EXT_RETURN_FAIL;
1718         }
1719         OPENSSL_free(encodedPoint);
1720 
1721         /*
1722          * This causes the crypto state to be updated based on the derived keys
1723          */
1724         s->s3.tmp.pkey = skey;
1725         if (ssl_derive(s, skey, ckey, 1) == 0) {
1726             /* SSLfatal() already called */
1727             return EXT_RETURN_FAIL;
1728         }
1729     } else {
1730         /* KEM mode */
1731         unsigned char *ct = NULL;
1732         size_t ctlen = 0;
1733 
1734         /*
1735          * This does not update the crypto state.
1736          *
1737          * The generated pms is stored in `s->s3.tmp.pms` to be later used via
1738          * ssl_gensecret().
1739          */
1740         if (ssl_encapsulate(s, ckey, &ct, &ctlen, 0) == 0) {
1741             /* SSLfatal() already called */
1742             return EXT_RETURN_FAIL;
1743         }
1744 
1745         if (ctlen == 0) {
1746             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1747             OPENSSL_free(ct);
1748             return EXT_RETURN_FAIL;
1749         }
1750 
1751         if (!WPACKET_sub_memcpy_u16(pkt, ct, ctlen)
1752                 || !WPACKET_close(pkt)) {
1753             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1754             OPENSSL_free(ct);
1755             return EXT_RETURN_FAIL;
1756         }
1757         OPENSSL_free(ct);
1758 
1759         /*
1760          * This causes the crypto state to be updated based on the generated pms
1761          */
1762         if (ssl_gensecret(s, s->s3.tmp.pms, s->s3.tmp.pmslen) == 0) {
1763             /* SSLfatal() already called */
1764             return EXT_RETURN_FAIL;
1765         }
1766     }
1767     s->s3.did_kex = 1;
1768     return EXT_RETURN_SENT;
1769 #else
1770     return EXT_RETURN_FAIL;
1771 #endif
1772 }
1773 
tls_construct_stoc_cookie(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1774 EXT_RETURN tls_construct_stoc_cookie(SSL_CONNECTION *s, WPACKET *pkt,
1775                                      unsigned int context,
1776                                      X509 *x, size_t chainidx)
1777 {
1778 #ifndef OPENSSL_NO_TLS1_3
1779     unsigned char *hashval1, *hashval2, *appcookie1, *appcookie2, *cookie;
1780     unsigned char *hmac, *hmac2;
1781     size_t startlen, ciphlen, totcookielen, hashlen, hmaclen, appcookielen;
1782     EVP_MD_CTX *hctx;
1783     EVP_PKEY *pkey;
1784     int ret = EXT_RETURN_FAIL;
1785     SSL_CTX *sctx = SSL_CONNECTION_GET_CTX(s);
1786     SSL *ssl = SSL_CONNECTION_GET_SSL(s);
1787 
1788     if ((s->s3.flags & TLS1_FLAGS_STATELESS) == 0)
1789         return EXT_RETURN_NOT_SENT;
1790 
1791     if (sctx->gen_stateless_cookie_cb == NULL) {
1792         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_NO_COOKIE_CALLBACK_SET);
1793         return EXT_RETURN_FAIL;
1794     }
1795 
1796     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_cookie)
1797             || !WPACKET_start_sub_packet_u16(pkt)
1798             || !WPACKET_start_sub_packet_u16(pkt)
1799             || !WPACKET_get_total_written(pkt, &startlen)
1800             || !WPACKET_reserve_bytes(pkt, MAX_COOKIE_SIZE, &cookie)
1801             || !WPACKET_put_bytes_u16(pkt, COOKIE_STATE_FORMAT_VERSION)
1802             || !WPACKET_put_bytes_u16(pkt, TLS1_3_VERSION)
1803             || !WPACKET_put_bytes_u16(pkt, s->s3.group_id)
1804             || !ssl->method->put_cipher_by_char(s->s3.tmp.new_cipher, pkt,
1805                                                 &ciphlen)
1806                /* Is there a key_share extension present in this HRR? */
1807             || !WPACKET_put_bytes_u8(pkt, s->s3.peer_tmp == NULL)
1808             || !WPACKET_put_bytes_u64(pkt, time(NULL))
1809             || !WPACKET_start_sub_packet_u16(pkt)
1810             || !WPACKET_reserve_bytes(pkt, EVP_MAX_MD_SIZE, &hashval1)) {
1811         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1812         return EXT_RETURN_FAIL;
1813     }
1814 
1815     /*
1816      * Get the hash of the initial ClientHello. ssl_handshake_hash() operates
1817      * on raw buffers, so we first reserve sufficient bytes (above) and then
1818      * subsequently allocate them (below)
1819      */
1820     if (!ssl3_digest_cached_records(s, 0)
1821             || !ssl_handshake_hash(s, hashval1, EVP_MAX_MD_SIZE, &hashlen)) {
1822         /* SSLfatal() already called */
1823         return EXT_RETURN_FAIL;
1824     }
1825 
1826     if (!WPACKET_allocate_bytes(pkt, hashlen, &hashval2)
1827             || !ossl_assert(hashval1 == hashval2)
1828             || !WPACKET_close(pkt)
1829             || !WPACKET_start_sub_packet_u8(pkt)
1830             || !WPACKET_reserve_bytes(pkt, SSL_COOKIE_LENGTH, &appcookie1)) {
1831         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1832         return EXT_RETURN_FAIL;
1833     }
1834 
1835     /* Generate the application cookie */
1836     if (sctx->gen_stateless_cookie_cb(ssl, appcookie1,
1837                                       &appcookielen) == 0) {
1838         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
1839         return EXT_RETURN_FAIL;
1840     }
1841 
1842     if (!WPACKET_allocate_bytes(pkt, appcookielen, &appcookie2)
1843             || !ossl_assert(appcookie1 == appcookie2)
1844             || !WPACKET_close(pkt)
1845             || !WPACKET_get_total_written(pkt, &totcookielen)
1846             || !WPACKET_reserve_bytes(pkt, SHA256_DIGEST_LENGTH, &hmac)) {
1847         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1848         return EXT_RETURN_FAIL;
1849     }
1850     hmaclen = SHA256_DIGEST_LENGTH;
1851 
1852     totcookielen -= startlen;
1853     if (!ossl_assert(totcookielen <= MAX_COOKIE_SIZE - SHA256_DIGEST_LENGTH)) {
1854         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1855         return EXT_RETURN_FAIL;
1856     }
1857 
1858     /* HMAC the cookie */
1859     hctx = EVP_MD_CTX_create();
1860     pkey = EVP_PKEY_new_raw_private_key_ex(sctx->libctx, "HMAC",
1861                                            sctx->propq,
1862                                            s->session_ctx->ext.cookie_hmac_key,
1863                                            sizeof(s->session_ctx->ext.cookie_hmac_key));
1864     if (hctx == NULL || pkey == NULL) {
1865         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_EVP_LIB);
1866         goto err;
1867     }
1868 
1869     if (EVP_DigestSignInit_ex(hctx, NULL, "SHA2-256", sctx->libctx,
1870                               sctx->propq, pkey, NULL) <= 0
1871             || EVP_DigestSign(hctx, hmac, &hmaclen, cookie,
1872                               totcookielen) <= 0) {
1873         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1874         goto err;
1875     }
1876 
1877     if (!ossl_assert(totcookielen + hmaclen <= MAX_COOKIE_SIZE)) {
1878         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1879         goto err;
1880     }
1881 
1882     if (!WPACKET_allocate_bytes(pkt, hmaclen, &hmac2)
1883             || !ossl_assert(hmac == hmac2)
1884             || !ossl_assert(cookie == hmac - totcookielen)
1885             || !WPACKET_close(pkt)
1886             || !WPACKET_close(pkt)) {
1887         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1888         goto err;
1889     }
1890 
1891     ret = EXT_RETURN_SENT;
1892 
1893  err:
1894     EVP_MD_CTX_free(hctx);
1895     EVP_PKEY_free(pkey);
1896     return ret;
1897 #else
1898     return EXT_RETURN_FAIL;
1899 #endif
1900 }
1901 
tls_construct_stoc_cryptopro_bug(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1902 EXT_RETURN tls_construct_stoc_cryptopro_bug(SSL_CONNECTION *s, WPACKET *pkt,
1903                                             unsigned int context, X509 *x,
1904                                             size_t chainidx)
1905 {
1906     const unsigned char cryptopro_ext[36] = {
1907         0xfd, 0xe8,         /* 65000 */
1908         0x00, 0x20,         /* 32 bytes length */
1909         0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
1910         0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
1911         0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
1912         0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
1913     };
1914 
1915     if (((s->s3.tmp.new_cipher->id & 0xFFFF) != 0x80
1916          && (s->s3.tmp.new_cipher->id & 0xFFFF) != 0x81)
1917             || (SSL_get_options(SSL_CONNECTION_GET_SSL(s))
1918                 & SSL_OP_CRYPTOPRO_TLSEXT_BUG) == 0)
1919         return EXT_RETURN_NOT_SENT;
1920 
1921     if (!WPACKET_memcpy(pkt, cryptopro_ext, sizeof(cryptopro_ext))) {
1922         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1923         return EXT_RETURN_FAIL;
1924     }
1925 
1926     return EXT_RETURN_SENT;
1927 }
1928 
tls_construct_stoc_early_data(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1929 EXT_RETURN tls_construct_stoc_early_data(SSL_CONNECTION *s, WPACKET *pkt,
1930                                          unsigned int context, X509 *x,
1931                                          size_t chainidx)
1932 {
1933     if (context == SSL_EXT_TLS1_3_NEW_SESSION_TICKET) {
1934         if (s->max_early_data == 0)
1935             return EXT_RETURN_NOT_SENT;
1936 
1937         if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_early_data)
1938                 || !WPACKET_start_sub_packet_u16(pkt)
1939                 || !WPACKET_put_bytes_u32(pkt, s->max_early_data)
1940                 || !WPACKET_close(pkt)) {
1941             SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1942             return EXT_RETURN_FAIL;
1943         }
1944 
1945         return EXT_RETURN_SENT;
1946     }
1947 
1948     if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED)
1949         return EXT_RETURN_NOT_SENT;
1950 
1951     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_early_data)
1952             || !WPACKET_start_sub_packet_u16(pkt)
1953             || !WPACKET_close(pkt)) {
1954         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1955         return EXT_RETURN_FAIL;
1956     }
1957 
1958     return EXT_RETURN_SENT;
1959 }
1960 
tls_construct_stoc_psk(SSL_CONNECTION * s,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1961 EXT_RETURN tls_construct_stoc_psk(SSL_CONNECTION *s, WPACKET *pkt,
1962                                   unsigned int context,
1963                                   X509 *x, size_t chainidx)
1964 {
1965     if (!s->hit)
1966         return EXT_RETURN_NOT_SENT;
1967 
1968     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk)
1969             || !WPACKET_start_sub_packet_u16(pkt)
1970             || !WPACKET_put_bytes_u16(pkt, s->ext.tick_identity)
1971             || !WPACKET_close(pkt)) {
1972         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1973         return EXT_RETURN_FAIL;
1974     }
1975 
1976     return EXT_RETURN_SENT;
1977 }
1978 
tls_construct_stoc_client_cert_type(SSL_CONNECTION * sc,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)1979 EXT_RETURN tls_construct_stoc_client_cert_type(SSL_CONNECTION *sc, WPACKET *pkt,
1980                                                unsigned int context,
1981                                                X509 *x, size_t chainidx)
1982 {
1983     if (sc->ext.client_cert_type_ctos == OSSL_CERT_TYPE_CTOS_ERROR
1984         && (send_certificate_request(sc)
1985             || sc->post_handshake_auth == SSL_PHA_EXT_RECEIVED)) {
1986         /* Did not receive an acceptable cert type - and doing client auth */
1987         SSLfatal(sc, SSL_AD_UNSUPPORTED_CERTIFICATE, SSL_R_BAD_EXTENSION);
1988         return EXT_RETURN_FAIL;
1989     }
1990 
1991     if (sc->ext.client_cert_type == TLSEXT_cert_type_x509) {
1992         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
1993         return EXT_RETURN_NOT_SENT;
1994     }
1995 
1996     /*
1997      * Note: only supposed to send this if we are going to do a cert request,
1998      * but TLSv1.3 could do a PHA request if the client supports it
1999      */
2000     if ((!send_certificate_request(sc) && sc->post_handshake_auth != SSL_PHA_EXT_RECEIVED)
2001             || sc->ext.client_cert_type_ctos != OSSL_CERT_TYPE_CTOS_GOOD
2002             || sc->client_cert_type == NULL) {
2003         /* if we don't send it, reset to TLSEXT_cert_type_x509 */
2004         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
2005         sc->ext.client_cert_type = TLSEXT_cert_type_x509;
2006         return EXT_RETURN_NOT_SENT;
2007     }
2008 
2009     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_client_cert_type)
2010             || !WPACKET_start_sub_packet_u16(pkt)
2011             || !WPACKET_put_bytes_u8(pkt, sc->ext.client_cert_type)
2012             || !WPACKET_close(pkt)) {
2013         SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
2014         return EXT_RETURN_FAIL;
2015     }
2016     return EXT_RETURN_SENT;
2017 }
2018 
2019 /* One of |pref|, |other| is configured and the values are sanitized */
reconcile_cert_type(const unsigned char * pref,size_t pref_len,const unsigned char * other,size_t other_len,uint8_t * chosen_cert_type)2020 static int reconcile_cert_type(const unsigned char *pref, size_t pref_len,
2021                                const unsigned char *other, size_t other_len,
2022                                uint8_t *chosen_cert_type)
2023 {
2024     size_t i;
2025 
2026     for (i = 0; i < pref_len; i++) {
2027         if (memchr(other, pref[i], other_len) != NULL) {
2028             *chosen_cert_type = pref[i];
2029             return OSSL_CERT_TYPE_CTOS_GOOD;
2030         }
2031     }
2032     return OSSL_CERT_TYPE_CTOS_ERROR;
2033 }
2034 
tls_parse_ctos_client_cert_type(SSL_CONNECTION * sc,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)2035 int tls_parse_ctos_client_cert_type(SSL_CONNECTION *sc, PACKET *pkt,
2036                                     unsigned int context,
2037                                     X509 *x, size_t chainidx)
2038 {
2039     PACKET supported_cert_types;
2040     const unsigned char *data;
2041     size_t len;
2042 
2043     /* Ignore the extension */
2044     if (sc->client_cert_type == NULL) {
2045         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
2046         sc->ext.client_cert_type = TLSEXT_cert_type_x509;
2047         return 1;
2048     }
2049 
2050     if (!PACKET_as_length_prefixed_1(pkt, &supported_cert_types)) {
2051         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_ERROR;
2052         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2053         return 0;
2054     }
2055     if ((len = PACKET_remaining(&supported_cert_types)) == 0) {
2056         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_ERROR;
2057         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2058         return 0;
2059     }
2060     if (!PACKET_get_bytes(&supported_cert_types, &data, len)) {
2061         sc->ext.client_cert_type_ctos = OSSL_CERT_TYPE_CTOS_ERROR;
2062         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2063         return 0;
2064     }
2065     /* client_cert_type: client (peer) has priority */
2066     sc->ext.client_cert_type_ctos = reconcile_cert_type(data, len,
2067                                                         sc->client_cert_type, sc->client_cert_type_len,
2068                                                         &sc->ext.client_cert_type);
2069 
2070     /* Ignore the error until sending - so we can check cert auth*/
2071     return 1;
2072 }
2073 
tls_construct_stoc_server_cert_type(SSL_CONNECTION * sc,WPACKET * pkt,unsigned int context,X509 * x,size_t chainidx)2074 EXT_RETURN tls_construct_stoc_server_cert_type(SSL_CONNECTION *sc, WPACKET *pkt,
2075                                                unsigned int context,
2076                                                X509 *x, size_t chainidx)
2077 {
2078     if (sc->ext.server_cert_type == TLSEXT_cert_type_x509) {
2079         sc->ext.server_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
2080         return EXT_RETURN_NOT_SENT;
2081     }
2082     if (sc->ext.server_cert_type_ctos != OSSL_CERT_TYPE_CTOS_GOOD
2083             || sc->server_cert_type == NULL) {
2084         /* if we don't send it, reset to TLSEXT_cert_type_x509 */
2085         sc->ext.server_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
2086         sc->ext.server_cert_type = TLSEXT_cert_type_x509;
2087         return EXT_RETURN_NOT_SENT;
2088     }
2089 
2090     if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_server_cert_type)
2091             || !WPACKET_start_sub_packet_u16(pkt)
2092             || !WPACKET_put_bytes_u8(pkt, sc->ext.server_cert_type)
2093             || !WPACKET_close(pkt)) {
2094         SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
2095         return EXT_RETURN_FAIL;
2096     }
2097     return EXT_RETURN_SENT;
2098 }
2099 
tls_parse_ctos_server_cert_type(SSL_CONNECTION * sc,PACKET * pkt,unsigned int context,X509 * x,size_t chainidx)2100 int tls_parse_ctos_server_cert_type(SSL_CONNECTION *sc, PACKET *pkt,
2101                                     unsigned int context,
2102                                     X509 *x, size_t chainidx)
2103 {
2104     PACKET supported_cert_types;
2105     const unsigned char *data;
2106     size_t len;
2107 
2108     /* Ignore the extension */
2109     if (sc->server_cert_type == NULL) {
2110         sc->ext.server_cert_type_ctos = OSSL_CERT_TYPE_CTOS_NONE;
2111         sc->ext.server_cert_type = TLSEXT_cert_type_x509;
2112         return 1;
2113     }
2114 
2115     if (!PACKET_as_length_prefixed_1(pkt, &supported_cert_types)) {
2116         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2117         return 0;
2118     }
2119 
2120     if ((len = PACKET_remaining(&supported_cert_types)) == 0) {
2121         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2122         return 0;
2123     }
2124     if (!PACKET_get_bytes(&supported_cert_types, &data, len)) {
2125         SSLfatal(sc, SSL_AD_DECODE_ERROR, SSL_R_BAD_EXTENSION);
2126         return 0;
2127     }
2128     /* server_cert_type: server (this) has priority */
2129     sc->ext.server_cert_type_ctos = reconcile_cert_type(sc->server_cert_type, sc->server_cert_type_len,
2130                                                         data, len,
2131                                                         &sc->ext.server_cert_type);
2132     if (sc->ext.server_cert_type_ctos == OSSL_CERT_TYPE_CTOS_GOOD)
2133         return 1;
2134 
2135     /* Did not receive an acceptable cert type */
2136     SSLfatal(sc, SSL_AD_UNSUPPORTED_CERTIFICATE, SSL_R_BAD_EXTENSION);
2137     return 0;
2138 }
2139