xref: /freebsd/crypto/openssl/ssl/t1_lib.c (revision ab40f58ccfe6c07ebefddc72f4661a52fe746353)
1 /* ssl/t1_lib.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 /* ====================================================================
59  * Copyright (c) 1998-2018 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111 
112 #include <stdio.h>
113 #include <openssl/objects.h>
114 #include <openssl/evp.h>
115 #include <openssl/hmac.h>
116 #ifndef OPENSSL_NO_EC
117 #ifdef OPENSSL_NO_EC2M
118 # include <openssl/ec.h>
119 #endif
120 #endif
121 #include <openssl/ocsp.h>
122 #include <openssl/rand.h>
123 #include "ssl_locl.h"
124 
125 const char tls1_version_str[] = "TLSv1" OPENSSL_VERSION_PTEXT;
126 
127 #ifndef OPENSSL_NO_TLSEXT
128 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
129                               const unsigned char *sess_id, int sesslen,
130                               SSL_SESSION **psess);
131 static int ssl_check_clienthello_tlsext_early(SSL *s);
132 int ssl_check_serverhello_tlsext(SSL *s);
133 #endif
134 
135 #define CHECKLEN(curr, val, limit) \
136     (((curr) >= (limit)) || (size_t)((limit) - (curr)) < (size_t)(val))
137 
138 SSL3_ENC_METHOD TLSv1_enc_data = {
139     tls1_enc,
140     tls1_mac,
141     tls1_setup_key_block,
142     tls1_generate_master_secret,
143     tls1_change_cipher_state,
144     tls1_final_finish_mac,
145     TLS1_FINISH_MAC_LENGTH,
146     tls1_cert_verify_mac,
147     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
148     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
149     tls1_alert_code,
150     tls1_export_keying_material,
151     0,
152     SSL3_HM_HEADER_LENGTH,
153     ssl3_set_handshake_header,
154     ssl3_handshake_write
155 };
156 
157 SSL3_ENC_METHOD TLSv1_1_enc_data = {
158     tls1_enc,
159     tls1_mac,
160     tls1_setup_key_block,
161     tls1_generate_master_secret,
162     tls1_change_cipher_state,
163     tls1_final_finish_mac,
164     TLS1_FINISH_MAC_LENGTH,
165     tls1_cert_verify_mac,
166     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
167     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
168     tls1_alert_code,
169     tls1_export_keying_material,
170     SSL_ENC_FLAG_EXPLICIT_IV,
171     SSL3_HM_HEADER_LENGTH,
172     ssl3_set_handshake_header,
173     ssl3_handshake_write
174 };
175 
176 SSL3_ENC_METHOD TLSv1_2_enc_data = {
177     tls1_enc,
178     tls1_mac,
179     tls1_setup_key_block,
180     tls1_generate_master_secret,
181     tls1_change_cipher_state,
182     tls1_final_finish_mac,
183     TLS1_FINISH_MAC_LENGTH,
184     tls1_cert_verify_mac,
185     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
186     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
187     tls1_alert_code,
188     tls1_export_keying_material,
189     SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS | SSL_ENC_FLAG_SHA256_PRF
190         | SSL_ENC_FLAG_TLS1_2_CIPHERS,
191     SSL3_HM_HEADER_LENGTH,
192     ssl3_set_handshake_header,
193     ssl3_handshake_write
194 };
195 
196 long tls1_default_timeout(void)
197 {
198     /*
199      * 2 hours, the 24 hours mentioned in the TLSv1 spec is way too long for
200      * http, the cache would over fill
201      */
202     return (60 * 60 * 2);
203 }
204 
205 int tls1_new(SSL *s)
206 {
207     if (!ssl3_new(s))
208         return (0);
209     s->method->ssl_clear(s);
210     return (1);
211 }
212 
213 void tls1_free(SSL *s)
214 {
215 #ifndef OPENSSL_NO_TLSEXT
216     if (s->tlsext_session_ticket) {
217         OPENSSL_free(s->tlsext_session_ticket);
218     }
219 #endif                          /* OPENSSL_NO_TLSEXT */
220     ssl3_free(s);
221 }
222 
223 void tls1_clear(SSL *s)
224 {
225     ssl3_clear(s);
226     s->version = s->method->version;
227 }
228 
229 #ifndef OPENSSL_NO_EC
230 
231 static int nid_list[] = {
232     NID_sect163k1,              /* sect163k1 (1) */
233     NID_sect163r1,              /* sect163r1 (2) */
234     NID_sect163r2,              /* sect163r2 (3) */
235     NID_sect193r1,              /* sect193r1 (4) */
236     NID_sect193r2,              /* sect193r2 (5) */
237     NID_sect233k1,              /* sect233k1 (6) */
238     NID_sect233r1,              /* sect233r1 (7) */
239     NID_sect239k1,              /* sect239k1 (8) */
240     NID_sect283k1,              /* sect283k1 (9) */
241     NID_sect283r1,              /* sect283r1 (10) */
242     NID_sect409k1,              /* sect409k1 (11) */
243     NID_sect409r1,              /* sect409r1 (12) */
244     NID_sect571k1,              /* sect571k1 (13) */
245     NID_sect571r1,              /* sect571r1 (14) */
246     NID_secp160k1,              /* secp160k1 (15) */
247     NID_secp160r1,              /* secp160r1 (16) */
248     NID_secp160r2,              /* secp160r2 (17) */
249     NID_secp192k1,              /* secp192k1 (18) */
250     NID_X9_62_prime192v1,       /* secp192r1 (19) */
251     NID_secp224k1,              /* secp224k1 (20) */
252     NID_secp224r1,              /* secp224r1 (21) */
253     NID_secp256k1,              /* secp256k1 (22) */
254     NID_X9_62_prime256v1,       /* secp256r1 (23) */
255     NID_secp384r1,              /* secp384r1 (24) */
256     NID_secp521r1,              /* secp521r1 (25) */
257     NID_brainpoolP256r1,        /* brainpoolP256r1 (26) */
258     NID_brainpoolP384r1,        /* brainpoolP384r1 (27) */
259     NID_brainpoolP512r1         /* brainpool512r1 (28) */
260 };
261 
262 static const unsigned char ecformats_default[] = {
263     TLSEXT_ECPOINTFORMAT_uncompressed,
264     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
265     TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
266 };
267 
268 /* The client's default curves / the server's 'auto' curves. */
269 static const unsigned char eccurves_auto[] = {
270     /* Prefer P-256 which has the fastest and most secure implementations. */
271     0, 23,                      /* secp256r1 (23) */
272     /* Other >= 256-bit prime curves. */
273     0, 25,                      /* secp521r1 (25) */
274     0, 28,                      /* brainpool512r1 (28) */
275     0, 27,                      /* brainpoolP384r1 (27) */
276     0, 24,                      /* secp384r1 (24) */
277     0, 26,                      /* brainpoolP256r1 (26) */
278     0, 22,                      /* secp256k1 (22) */
279 # ifndef OPENSSL_NO_EC2M
280     /* >= 256-bit binary curves. */
281     0, 14,                      /* sect571r1 (14) */
282     0, 13,                      /* sect571k1 (13) */
283     0, 11,                      /* sect409k1 (11) */
284     0, 12,                      /* sect409r1 (12) */
285     0, 9,                       /* sect283k1 (9) */
286     0, 10,                      /* sect283r1 (10) */
287 # endif
288 };
289 
290 static const unsigned char eccurves_all[] = {
291     /* Prefer P-256 which has the fastest and most secure implementations. */
292     0, 23,                      /* secp256r1 (23) */
293     /* Other >= 256-bit prime curves. */
294     0, 25,                      /* secp521r1 (25) */
295     0, 28,                      /* brainpool512r1 (28) */
296     0, 27,                      /* brainpoolP384r1 (27) */
297     0, 24,                      /* secp384r1 (24) */
298     0, 26,                      /* brainpoolP256r1 (26) */
299     0, 22,                      /* secp256k1 (22) */
300 # ifndef OPENSSL_NO_EC2M
301     /* >= 256-bit binary curves. */
302     0, 14,                      /* sect571r1 (14) */
303     0, 13,                      /* sect571k1 (13) */
304     0, 11,                      /* sect409k1 (11) */
305     0, 12,                      /* sect409r1 (12) */
306     0, 9,                       /* sect283k1 (9) */
307     0, 10,                      /* sect283r1 (10) */
308 # endif
309     /*
310      * Remaining curves disabled by default but still permitted if set
311      * via an explicit callback or parameters.
312      */
313     0, 20,                      /* secp224k1 (20) */
314     0, 21,                      /* secp224r1 (21) */
315     0, 18,                      /* secp192k1 (18) */
316     0, 19,                      /* secp192r1 (19) */
317     0, 15,                      /* secp160k1 (15) */
318     0, 16,                      /* secp160r1 (16) */
319     0, 17,                      /* secp160r2 (17) */
320 # ifndef OPENSSL_NO_EC2M
321     0, 8,                       /* sect239k1 (8) */
322     0, 6,                       /* sect233k1 (6) */
323     0, 7,                       /* sect233r1 (7) */
324     0, 4,                       /* sect193r1 (4) */
325     0, 5,                       /* sect193r2 (5) */
326     0, 1,                       /* sect163k1 (1) */
327     0, 2,                       /* sect163r1 (2) */
328     0, 3,                       /* sect163r2 (3) */
329 # endif
330 };
331 
332 static const unsigned char suiteb_curves[] = {
333     0, TLSEXT_curve_P_256,
334     0, TLSEXT_curve_P_384
335 };
336 
337 # ifdef OPENSSL_FIPS
338 /* Brainpool not allowed in FIPS mode */
339 static const unsigned char fips_curves_default[] = {
340 #  ifndef OPENSSL_NO_EC2M
341     0, 14,                      /* sect571r1 (14) */
342     0, 13,                      /* sect571k1 (13) */
343 #  endif
344     0, 25,                      /* secp521r1 (25) */
345 #  ifndef OPENSSL_NO_EC2M
346     0, 11,                      /* sect409k1 (11) */
347     0, 12,                      /* sect409r1 (12) */
348 #  endif
349     0, 24,                      /* secp384r1 (24) */
350 #  ifndef OPENSSL_NO_EC2M
351     0, 9,                       /* sect283k1 (9) */
352     0, 10,                      /* sect283r1 (10) */
353 #  endif
354     0, 22,                      /* secp256k1 (22) */
355     0, 23,                      /* secp256r1 (23) */
356 #  ifndef OPENSSL_NO_EC2M
357     0, 8,                       /* sect239k1 (8) */
358     0, 6,                       /* sect233k1 (6) */
359     0, 7,                       /* sect233r1 (7) */
360 #  endif
361     0, 20,                      /* secp224k1 (20) */
362     0, 21,                      /* secp224r1 (21) */
363 #  ifndef OPENSSL_NO_EC2M
364     0, 4,                       /* sect193r1 (4) */
365     0, 5,                       /* sect193r2 (5) */
366 #  endif
367     0, 18,                      /* secp192k1 (18) */
368     0, 19,                      /* secp192r1 (19) */
369 #  ifndef OPENSSL_NO_EC2M
370     0, 1,                       /* sect163k1 (1) */
371     0, 2,                       /* sect163r1 (2) */
372     0, 3,                       /* sect163r2 (3) */
373 #  endif
374     0, 15,                      /* secp160k1 (15) */
375     0, 16,                      /* secp160r1 (16) */
376     0, 17,                      /* secp160r2 (17) */
377 };
378 # endif
379 
380 int tls1_ec_curve_id2nid(int curve_id)
381 {
382     /* ECC curves from RFC 4492 and RFC 7027 */
383     if ((curve_id < 1) || ((unsigned int)curve_id >
384                            sizeof(nid_list) / sizeof(nid_list[0])))
385         return 0;
386     return nid_list[curve_id - 1];
387 }
388 
389 int tls1_ec_nid2curve_id(int nid)
390 {
391     /* ECC curves from RFC 4492 and RFC 7027 */
392     switch (nid) {
393     case NID_sect163k1:        /* sect163k1 (1) */
394         return 1;
395     case NID_sect163r1:        /* sect163r1 (2) */
396         return 2;
397     case NID_sect163r2:        /* sect163r2 (3) */
398         return 3;
399     case NID_sect193r1:        /* sect193r1 (4) */
400         return 4;
401     case NID_sect193r2:        /* sect193r2 (5) */
402         return 5;
403     case NID_sect233k1:        /* sect233k1 (6) */
404         return 6;
405     case NID_sect233r1:        /* sect233r1 (7) */
406         return 7;
407     case NID_sect239k1:        /* sect239k1 (8) */
408         return 8;
409     case NID_sect283k1:        /* sect283k1 (9) */
410         return 9;
411     case NID_sect283r1:        /* sect283r1 (10) */
412         return 10;
413     case NID_sect409k1:        /* sect409k1 (11) */
414         return 11;
415     case NID_sect409r1:        /* sect409r1 (12) */
416         return 12;
417     case NID_sect571k1:        /* sect571k1 (13) */
418         return 13;
419     case NID_sect571r1:        /* sect571r1 (14) */
420         return 14;
421     case NID_secp160k1:        /* secp160k1 (15) */
422         return 15;
423     case NID_secp160r1:        /* secp160r1 (16) */
424         return 16;
425     case NID_secp160r2:        /* secp160r2 (17) */
426         return 17;
427     case NID_secp192k1:        /* secp192k1 (18) */
428         return 18;
429     case NID_X9_62_prime192v1: /* secp192r1 (19) */
430         return 19;
431     case NID_secp224k1:        /* secp224k1 (20) */
432         return 20;
433     case NID_secp224r1:        /* secp224r1 (21) */
434         return 21;
435     case NID_secp256k1:        /* secp256k1 (22) */
436         return 22;
437     case NID_X9_62_prime256v1: /* secp256r1 (23) */
438         return 23;
439     case NID_secp384r1:        /* secp384r1 (24) */
440         return 24;
441     case NID_secp521r1:        /* secp521r1 (25) */
442         return 25;
443     case NID_brainpoolP256r1:  /* brainpoolP256r1 (26) */
444         return 26;
445     case NID_brainpoolP384r1:  /* brainpoolP384r1 (27) */
446         return 27;
447     case NID_brainpoolP512r1:  /* brainpool512r1 (28) */
448         return 28;
449     default:
450         return 0;
451     }
452 }
453 
454 /*
455  * Get curves list, if "sess" is set return client curves otherwise
456  * preferred list.
457  * Sets |num_curves| to the number of curves in the list, i.e.,
458  * the length of |pcurves| is 2 * num_curves.
459  * Returns 1 on success and 0 if the client curves list has invalid format.
460  * The latter indicates an internal error: we should not be accepting such
461  * lists in the first place.
462  * TODO(emilia): we should really be storing the curves list in explicitly
463  * parsed form instead. (However, this would affect binary compatibility
464  * so cannot happen in the 1.0.x series.)
465  */
466 static int tls1_get_curvelist(SSL *s, int sess,
467                               const unsigned char **pcurves,
468                               size_t *num_curves)
469 {
470     size_t pcurveslen = 0;
471     if (sess) {
472         *pcurves = s->session->tlsext_ellipticcurvelist;
473         pcurveslen = s->session->tlsext_ellipticcurvelist_length;
474     } else {
475         /* For Suite B mode only include P-256, P-384 */
476         switch (tls1_suiteb(s)) {
477         case SSL_CERT_FLAG_SUITEB_128_LOS:
478             *pcurves = suiteb_curves;
479             pcurveslen = sizeof(suiteb_curves);
480             break;
481 
482         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
483             *pcurves = suiteb_curves;
484             pcurveslen = 2;
485             break;
486 
487         case SSL_CERT_FLAG_SUITEB_192_LOS:
488             *pcurves = suiteb_curves + 2;
489             pcurveslen = 2;
490             break;
491         default:
492             *pcurves = s->tlsext_ellipticcurvelist;
493             pcurveslen = s->tlsext_ellipticcurvelist_length;
494         }
495         if (!*pcurves) {
496 # ifdef OPENSSL_FIPS
497             if (FIPS_mode()) {
498                 *pcurves = fips_curves_default;
499                 pcurveslen = sizeof(fips_curves_default);
500             } else
501 # endif
502             {
503                 if (!s->server || s->cert->ecdh_tmp_auto) {
504                     *pcurves = eccurves_auto;
505                     pcurveslen = sizeof(eccurves_auto);
506                 } else {
507                     *pcurves = eccurves_all;
508                     pcurveslen = sizeof(eccurves_all);
509                 }
510             }
511         }
512     }
513     /* We do not allow odd length arrays to enter the system. */
514     if (pcurveslen & 1) {
515         SSLerr(SSL_F_TLS1_GET_CURVELIST, ERR_R_INTERNAL_ERROR);
516         *num_curves = 0;
517         return 0;
518     } else {
519         *num_curves = pcurveslen / 2;
520         return 1;
521     }
522 }
523 
524 /* Check a curve is one of our preferences */
525 int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
526 {
527     const unsigned char *curves;
528     size_t num_curves, i;
529     unsigned int suiteb_flags = tls1_suiteb(s);
530     if (len != 3 || p[0] != NAMED_CURVE_TYPE)
531         return 0;
532     /* Check curve matches Suite B preferences */
533     if (suiteb_flags) {
534         unsigned long cid = s->s3->tmp.new_cipher->id;
535         if (p[1])
536             return 0;
537         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256) {
538             if (p[2] != TLSEXT_curve_P_256)
539                 return 0;
540         } else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384) {
541             if (p[2] != TLSEXT_curve_P_384)
542                 return 0;
543         } else                  /* Should never happen */
544             return 0;
545     }
546     if (!tls1_get_curvelist(s, 0, &curves, &num_curves))
547         return 0;
548     for (i = 0; i < num_curves; i++, curves += 2) {
549         if (p[1] == curves[0] && p[2] == curves[1])
550             return 1;
551     }
552     return 0;
553 }
554 
555 /*-
556  * Return |nmatch|th shared curve or NID_undef if there is no match.
557  * For nmatch == -1, return number of  matches
558  * For nmatch == -2, return the NID of the curve to use for
559  * an EC tmp key, or NID_undef if there is no match.
560  */
561 int tls1_shared_curve(SSL *s, int nmatch)
562 {
563     const unsigned char *pref, *supp;
564     size_t num_pref, num_supp, i, j;
565     int k;
566     /* Can't do anything on client side */
567     if (s->server == 0)
568         return -1;
569     if (nmatch == -2) {
570         if (tls1_suiteb(s)) {
571             /*
572              * For Suite B ciphersuite determines curve: we already know
573              * these are acceptable due to previous checks.
574              */
575             unsigned long cid = s->s3->tmp.new_cipher->id;
576             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
577                 return NID_X9_62_prime256v1; /* P-256 */
578             if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
579                 return NID_secp384r1; /* P-384 */
580             /* Should never happen */
581             return NID_undef;
582         }
583         /* If not Suite B just return first preference shared curve */
584         nmatch = 0;
585     }
586     /*
587      * Avoid truncation. tls1_get_curvelist takes an int
588      * but s->options is a long...
589      */
590     if (!tls1_get_curvelist
591         (s, (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0, &supp,
592          &num_supp))
593         /* In practice, NID_undef == 0 but let's be precise. */
594         return nmatch == -1 ? 0 : NID_undef;
595     if (!tls1_get_curvelist
596         (s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE), &pref,
597          &num_pref))
598         return nmatch == -1 ? 0 : NID_undef;
599 
600     /*
601      * If the client didn't send the elliptic_curves extension all of them
602      * are allowed.
603      */
604     if (num_supp == 0 && (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) != 0) {
605         supp = eccurves_all;
606         num_supp = sizeof(eccurves_all) / 2;
607     } else if (num_pref == 0 &&
608         (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE) == 0) {
609         pref = eccurves_all;
610         num_pref = sizeof(eccurves_all) / 2;
611     }
612 
613     k = 0;
614     for (i = 0; i < num_pref; i++, pref += 2) {
615         const unsigned char *tsupp = supp;
616         for (j = 0; j < num_supp; j++, tsupp += 2) {
617             if (pref[0] == tsupp[0] && pref[1] == tsupp[1]) {
618                 if (nmatch == k) {
619                     int id = (pref[0] << 8) | pref[1];
620                     return tls1_ec_curve_id2nid(id);
621                 }
622                 k++;
623             }
624         }
625     }
626     if (nmatch == -1)
627         return k;
628     /* Out of range (nmatch > k). */
629     return NID_undef;
630 }
631 
632 int tls1_set_curves(unsigned char **pext, size_t *pextlen,
633                     int *curves, size_t ncurves)
634 {
635     unsigned char *clist, *p;
636     size_t i;
637     /*
638      * Bitmap of curves included to detect duplicates: only works while curve
639      * ids < 32
640      */
641     unsigned long dup_list = 0;
642 # ifdef OPENSSL_NO_EC2M
643     EC_GROUP *curve;
644 # endif
645 
646     clist = OPENSSL_malloc(ncurves * 2);
647     if (!clist)
648         return 0;
649     for (i = 0, p = clist; i < ncurves; i++) {
650         unsigned long idmask;
651         int id;
652         id = tls1_ec_nid2curve_id(curves[i]);
653 # ifdef OPENSSL_FIPS
654         /* NB: 25 is last curve ID supported by FIPS module */
655         if (FIPS_mode() && id > 25) {
656             OPENSSL_free(clist);
657             return 0;
658         }
659 # endif
660 # ifdef OPENSSL_NO_EC2M
661         curve = EC_GROUP_new_by_curve_name(curves[i]);
662         if (!curve || EC_METHOD_get_field_type(EC_GROUP_method_of(curve))
663             == NID_X9_62_characteristic_two_field) {
664             if (curve)
665                 EC_GROUP_free(curve);
666             OPENSSL_free(clist);
667             return 0;
668         } else
669             EC_GROUP_free(curve);
670 # endif
671         idmask = 1L << id;
672         if (!id || (dup_list & idmask)) {
673             OPENSSL_free(clist);
674             return 0;
675         }
676         dup_list |= idmask;
677         s2n(id, p);
678     }
679     if (*pext)
680         OPENSSL_free(*pext);
681     *pext = clist;
682     *pextlen = ncurves * 2;
683     return 1;
684 }
685 
686 # define MAX_CURVELIST   28
687 
688 typedef struct {
689     size_t nidcnt;
690     int nid_arr[MAX_CURVELIST];
691 } nid_cb_st;
692 
693 static int nid_cb(const char *elem, int len, void *arg)
694 {
695     nid_cb_st *narg = arg;
696     size_t i;
697     int nid;
698     char etmp[20];
699     if (elem == NULL)
700         return 0;
701     if (narg->nidcnt == MAX_CURVELIST)
702         return 0;
703     if (len > (int)(sizeof(etmp) - 1))
704         return 0;
705     memcpy(etmp, elem, len);
706     etmp[len] = 0;
707     nid = EC_curve_nist2nid(etmp);
708     if (nid == NID_undef)
709         nid = OBJ_sn2nid(etmp);
710     if (nid == NID_undef)
711         nid = OBJ_ln2nid(etmp);
712     if (nid == NID_undef)
713         return 0;
714     for (i = 0; i < narg->nidcnt; i++)
715         if (narg->nid_arr[i] == nid)
716             return 0;
717     narg->nid_arr[narg->nidcnt++] = nid;
718     return 1;
719 }
720 
721 /* Set curves based on a colon separate list */
722 int tls1_set_curves_list(unsigned char **pext, size_t *pextlen,
723                          const char *str)
724 {
725     nid_cb_st ncb;
726     ncb.nidcnt = 0;
727     if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
728         return 0;
729     if (pext == NULL)
730         return 1;
731     return tls1_set_curves(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
732 }
733 
734 /* For an EC key set TLS id and required compression based on parameters */
735 static int tls1_set_ec_id(unsigned char *curve_id, unsigned char *comp_id,
736                           EC_KEY *ec)
737 {
738     int is_prime, id;
739     const EC_GROUP *grp;
740     const EC_METHOD *meth;
741     if (!ec)
742         return 0;
743     /* Determine if it is a prime field */
744     grp = EC_KEY_get0_group(ec);
745     if (!grp)
746         return 0;
747     meth = EC_GROUP_method_of(grp);
748     if (!meth)
749         return 0;
750     if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field)
751         is_prime = 1;
752     else
753         is_prime = 0;
754     /* Determine curve ID */
755     id = EC_GROUP_get_curve_name(grp);
756     id = tls1_ec_nid2curve_id(id);
757     /* If we have an ID set it, otherwise set arbitrary explicit curve */
758     if (id) {
759         curve_id[0] = 0;
760         curve_id[1] = (unsigned char)id;
761     } else {
762         curve_id[0] = 0xff;
763         if (is_prime)
764             curve_id[1] = 0x01;
765         else
766             curve_id[1] = 0x02;
767     }
768     if (comp_id) {
769         if (EC_KEY_get0_public_key(ec) == NULL)
770             return 0;
771         if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED) {
772             if (is_prime)
773                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
774             else
775                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
776         } else
777             *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
778     }
779     return 1;
780 }
781 
782 /* Check an EC key is compatible with extensions */
783 static int tls1_check_ec_key(SSL *s,
784                              unsigned char *curve_id, unsigned char *comp_id)
785 {
786     const unsigned char *pformats, *pcurves;
787     size_t num_formats, num_curves, i;
788     int j;
789     /*
790      * If point formats extension present check it, otherwise everything is
791      * supported (see RFC4492).
792      */
793     if (comp_id && s->session->tlsext_ecpointformatlist) {
794         pformats = s->session->tlsext_ecpointformatlist;
795         num_formats = s->session->tlsext_ecpointformatlist_length;
796         for (i = 0; i < num_formats; i++, pformats++) {
797             if (*comp_id == *pformats)
798                 break;
799         }
800         if (i == num_formats)
801             return 0;
802     }
803     if (!curve_id)
804         return 1;
805     /* Check curve is consistent with client and server preferences */
806     for (j = 0; j <= 1; j++) {
807         if (!tls1_get_curvelist(s, j, &pcurves, &num_curves))
808             return 0;
809         if (j == 1 && num_curves == 0) {
810             /*
811              * If we've not received any curves then skip this check.
812              * RFC 4492 does not require the supported elliptic curves extension
813              * so if it is not sent we can just choose any curve.
814              * It is invalid to send an empty list in the elliptic curves
815              * extension, so num_curves == 0 always means no extension.
816              */
817             break;
818         }
819         for (i = 0; i < num_curves; i++, pcurves += 2) {
820             if (pcurves[0] == curve_id[0] && pcurves[1] == curve_id[1])
821                 break;
822         }
823         if (i == num_curves)
824             return 0;
825         /* For clients can only check sent curve list */
826         if (!s->server)
827             return 1;
828     }
829     return 1;
830 }
831 
832 static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
833                                 size_t *num_formats)
834 {
835     /*
836      * If we have a custom point format list use it otherwise use default
837      */
838     if (s->tlsext_ecpointformatlist) {
839         *pformats = s->tlsext_ecpointformatlist;
840         *num_formats = s->tlsext_ecpointformatlist_length;
841     } else {
842         *pformats = ecformats_default;
843         /* For Suite B we don't support char2 fields */
844         if (tls1_suiteb(s))
845             *num_formats = sizeof(ecformats_default) - 1;
846         else
847             *num_formats = sizeof(ecformats_default);
848     }
849 }
850 
851 /*
852  * Check cert parameters compatible with extensions: currently just checks EC
853  * certificates have compatible curves and compression.
854  */
855 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
856 {
857     unsigned char comp_id, curve_id[2];
858     EVP_PKEY *pkey;
859     int rv;
860     pkey = X509_get_pubkey(x);
861     if (!pkey)
862         return 0;
863     /* If not EC nothing to do */
864     if (pkey->type != EVP_PKEY_EC) {
865         EVP_PKEY_free(pkey);
866         return 1;
867     }
868     rv = tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec);
869     EVP_PKEY_free(pkey);
870     if (!rv)
871         return 0;
872     /*
873      * Can't check curve_id for client certs as we don't have a supported
874      * curves extension.
875      */
876     rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
877     if (!rv)
878         return 0;
879     /*
880      * Special case for suite B. We *MUST* sign using SHA256+P-256 or
881      * SHA384+P-384, adjust digest if necessary.
882      */
883     if (set_ee_md && tls1_suiteb(s)) {
884         int check_md;
885         size_t i;
886         CERT *c = s->cert;
887         if (curve_id[0])
888             return 0;
889         /* Check to see we have necessary signing algorithm */
890         if (curve_id[1] == TLSEXT_curve_P_256)
891             check_md = NID_ecdsa_with_SHA256;
892         else if (curve_id[1] == TLSEXT_curve_P_384)
893             check_md = NID_ecdsa_with_SHA384;
894         else
895             return 0;           /* Should never happen */
896         for (i = 0; i < c->shared_sigalgslen; i++)
897             if (check_md == c->shared_sigalgs[i].signandhash_nid)
898                 break;
899         if (i == c->shared_sigalgslen)
900             return 0;
901         if (set_ee_md == 2) {
902             if (check_md == NID_ecdsa_with_SHA256)
903                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
904             else
905                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
906         }
907     }
908     return rv;
909 }
910 
911 # ifndef OPENSSL_NO_ECDH
912 /* Check EC temporary key is compatible with client extensions */
913 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
914 {
915     unsigned char curve_id[2];
916     EC_KEY *ec = s->cert->ecdh_tmp;
917 #  ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
918     /* Allow any curve: not just those peer supports */
919     if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
920         return 1;
921 #  endif
922     /*
923      * If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384, no other
924      * curves permitted.
925      */
926     if (tls1_suiteb(s)) {
927         /* Curve to check determined by ciphersuite */
928         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
929             curve_id[1] = TLSEXT_curve_P_256;
930         else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
931             curve_id[1] = TLSEXT_curve_P_384;
932         else
933             return 0;
934         curve_id[0] = 0;
935         /* Check this curve is acceptable */
936         if (!tls1_check_ec_key(s, curve_id, NULL))
937             return 0;
938         /* If auto or setting curve from callback assume OK */
939         if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
940             return 1;
941         /* Otherwise check curve is acceptable */
942         else {
943             unsigned char curve_tmp[2];
944             if (!ec)
945                 return 0;
946             if (!tls1_set_ec_id(curve_tmp, NULL, ec))
947                 return 0;
948             if (!curve_tmp[0] || curve_tmp[1] == curve_id[1])
949                 return 1;
950             return 0;
951         }
952 
953     }
954     if (s->cert->ecdh_tmp_auto) {
955         /* Need a shared curve */
956         if (tls1_shared_curve(s, 0))
957             return 1;
958         else
959             return 0;
960     }
961     if (!ec) {
962         if (s->cert->ecdh_tmp_cb)
963             return 1;
964         else
965             return 0;
966     }
967     if (!tls1_set_ec_id(curve_id, NULL, ec))
968         return 0;
969 /* Set this to allow use of invalid curves for testing */
970 #  if 0
971     return 1;
972 #  else
973     return tls1_check_ec_key(s, curve_id, NULL);
974 #  endif
975 }
976 # endif                         /* OPENSSL_NO_ECDH */
977 
978 #else
979 
980 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
981 {
982     return 1;
983 }
984 
985 #endif                          /* OPENSSL_NO_EC */
986 
987 #ifndef OPENSSL_NO_TLSEXT
988 
989 /*
990  * List of supported signature algorithms and hashes. Should make this
991  * customisable at some point, for now include everything we support.
992  */
993 
994 # ifdef OPENSSL_NO_RSA
995 #  define tlsext_sigalg_rsa(md) /* */
996 # else
997 #  define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
998 # endif
999 
1000 # ifdef OPENSSL_NO_DSA
1001 #  define tlsext_sigalg_dsa(md) /* */
1002 # else
1003 #  define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
1004 # endif
1005 
1006 # ifdef OPENSSL_NO_ECDSA
1007 #  define tlsext_sigalg_ecdsa(md)
1008                                 /* */
1009 # else
1010 #  define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
1011 # endif
1012 
1013 # define tlsext_sigalg(md) \
1014                 tlsext_sigalg_rsa(md) \
1015                 tlsext_sigalg_dsa(md) \
1016                 tlsext_sigalg_ecdsa(md)
1017 
1018 static unsigned char tls12_sigalgs[] = {
1019 # ifndef OPENSSL_NO_SHA512
1020     tlsext_sigalg(TLSEXT_hash_sha512)
1021         tlsext_sigalg(TLSEXT_hash_sha384)
1022 # endif
1023 # ifndef OPENSSL_NO_SHA256
1024         tlsext_sigalg(TLSEXT_hash_sha256)
1025         tlsext_sigalg(TLSEXT_hash_sha224)
1026 # endif
1027 # ifndef OPENSSL_NO_SHA
1028         tlsext_sigalg(TLSEXT_hash_sha1)
1029 # endif
1030 };
1031 
1032 # ifndef OPENSSL_NO_ECDSA
1033 static unsigned char suiteb_sigalgs[] = {
1034     tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
1035         tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
1036 };
1037 # endif
1038 size_t tls12_get_psigalgs(SSL *s, int sent, const unsigned char **psigs)
1039 {
1040     /*
1041      * If Suite B mode use Suite B sigalgs only, ignore any other
1042      * preferences.
1043      */
1044 # ifndef OPENSSL_NO_EC
1045     switch (tls1_suiteb(s)) {
1046     case SSL_CERT_FLAG_SUITEB_128_LOS:
1047         *psigs = suiteb_sigalgs;
1048         return sizeof(suiteb_sigalgs);
1049 
1050     case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
1051         *psigs = suiteb_sigalgs;
1052         return 2;
1053 
1054     case SSL_CERT_FLAG_SUITEB_192_LOS:
1055         *psigs = suiteb_sigalgs + 2;
1056         return 2;
1057     }
1058 # endif
1059     /* If server use client authentication sigalgs if not NULL */
1060     if (s->server == sent && s->cert->client_sigalgs) {
1061         *psigs = s->cert->client_sigalgs;
1062         return s->cert->client_sigalgslen;
1063     } else if (s->cert->conf_sigalgs) {
1064         *psigs = s->cert->conf_sigalgs;
1065         return s->cert->conf_sigalgslen;
1066     } else {
1067         *psigs = tls12_sigalgs;
1068         return sizeof(tls12_sigalgs);
1069     }
1070 }
1071 
1072 /*
1073  * Check signature algorithm is consistent with sent supported signature
1074  * algorithms and if so return relevant digest.
1075  */
1076 int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
1077                             const unsigned char *sig, EVP_PKEY *pkey)
1078 {
1079     const unsigned char *sent_sigs;
1080     size_t sent_sigslen, i;
1081     int sigalg = tls12_get_sigid(pkey);
1082     /* Should never happen */
1083     if (sigalg == -1)
1084         return -1;
1085     /* Check key type is consistent with signature */
1086     if (sigalg != (int)sig[1]) {
1087         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
1088         return 0;
1089     }
1090 # ifndef OPENSSL_NO_EC
1091     if (pkey->type == EVP_PKEY_EC) {
1092         unsigned char curve_id[2], comp_id;
1093         /* Check compression and curve matches extensions */
1094         if (!tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec))
1095             return 0;
1096         if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id)) {
1097             SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_CURVE);
1098             return 0;
1099         }
1100         /* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
1101         if (tls1_suiteb(s)) {
1102             if (curve_id[0])
1103                 return 0;
1104             if (curve_id[1] == TLSEXT_curve_P_256) {
1105                 if (sig[0] != TLSEXT_hash_sha256) {
1106                     SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
1107                            SSL_R_ILLEGAL_SUITEB_DIGEST);
1108                     return 0;
1109                 }
1110             } else if (curve_id[1] == TLSEXT_curve_P_384) {
1111                 if (sig[0] != TLSEXT_hash_sha384) {
1112                     SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
1113                            SSL_R_ILLEGAL_SUITEB_DIGEST);
1114                     return 0;
1115                 }
1116             } else
1117                 return 0;
1118         }
1119     } else if (tls1_suiteb(s))
1120         return 0;
1121 # endif
1122 
1123     /* Check signature matches a type we sent */
1124     sent_sigslen = tls12_get_psigalgs(s, 1, &sent_sigs);
1125     for (i = 0; i < sent_sigslen; i += 2, sent_sigs += 2) {
1126         if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
1127             break;
1128     }
1129     /* Allow fallback to SHA1 if not strict mode */
1130     if (i == sent_sigslen
1131         && (sig[0] != TLSEXT_hash_sha1
1132             || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
1133         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_WRONG_SIGNATURE_TYPE);
1134         return 0;
1135     }
1136     *pmd = tls12_get_hash(sig[0]);
1137     if (*pmd == NULL) {
1138         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG, SSL_R_UNKNOWN_DIGEST);
1139         return 0;
1140     }
1141     /*
1142      * Store the digest used so applications can retrieve it if they wish.
1143      */
1144     if (s->session && s->session->sess_cert)
1145         s->session->sess_cert->peer_key->digest = *pmd;
1146     return 1;
1147 }
1148 
1149 /*
1150  * Get a mask of disabled algorithms: an algorithm is disabled if it isn't
1151  * supported or doesn't appear in supported signature algorithms. Unlike
1152  * ssl_cipher_get_disabled this applies to a specific session and not global
1153  * settings.
1154  */
1155 void ssl_set_client_disabled(SSL *s)
1156 {
1157     CERT *c = s->cert;
1158     const unsigned char *sigalgs;
1159     size_t i, sigalgslen;
1160     int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
1161     c->mask_a = 0;
1162     c->mask_k = 0;
1163     /* Don't allow TLS 1.2 only ciphers if we don't suppport them */
1164     if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s))
1165         c->mask_ssl = SSL_TLSV1_2;
1166     else
1167         c->mask_ssl = 0;
1168     /*
1169      * Now go through all signature algorithms seeing if we support any for
1170      * RSA, DSA, ECDSA. Do this for all versions not just TLS 1.2.
1171      */
1172     sigalgslen = tls12_get_psigalgs(s, 1, &sigalgs);
1173     for (i = 0; i < sigalgslen; i += 2, sigalgs += 2) {
1174         switch (sigalgs[1]) {
1175 # ifndef OPENSSL_NO_RSA
1176         case TLSEXT_signature_rsa:
1177             have_rsa = 1;
1178             break;
1179 # endif
1180 # ifndef OPENSSL_NO_DSA
1181         case TLSEXT_signature_dsa:
1182             have_dsa = 1;
1183             break;
1184 # endif
1185 # ifndef OPENSSL_NO_ECDSA
1186         case TLSEXT_signature_ecdsa:
1187             have_ecdsa = 1;
1188             break;
1189 # endif
1190         }
1191     }
1192     /*
1193      * Disable auth and static DH if we don't include any appropriate
1194      * signature algorithms.
1195      */
1196     if (!have_rsa) {
1197         c->mask_a |= SSL_aRSA;
1198         c->mask_k |= SSL_kDHr | SSL_kECDHr;
1199     }
1200     if (!have_dsa) {
1201         c->mask_a |= SSL_aDSS;
1202         c->mask_k |= SSL_kDHd;
1203     }
1204     if (!have_ecdsa) {
1205         c->mask_a |= SSL_aECDSA;
1206         c->mask_k |= SSL_kECDHe;
1207     }
1208 # ifndef OPENSSL_NO_KRB5
1209     if (!kssl_tgt_is_available(s->kssl_ctx)) {
1210         c->mask_a |= SSL_aKRB5;
1211         c->mask_k |= SSL_kKRB5;
1212     }
1213 # endif
1214 # ifndef OPENSSL_NO_PSK
1215     /* with PSK there must be client callback set */
1216     if (!s->psk_client_callback) {
1217         c->mask_a |= SSL_aPSK;
1218         c->mask_k |= SSL_kPSK;
1219     }
1220 # endif                         /* OPENSSL_NO_PSK */
1221 # ifndef OPENSSL_NO_SRP
1222     if (!(s->srp_ctx.srp_Mask & SSL_kSRP)) {
1223         c->mask_a |= SSL_aSRP;
1224         c->mask_k |= SSL_kSRP;
1225     }
1226 # endif
1227     c->valid = 1;
1228 }
1229 
1230 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf,
1231                                           unsigned char *limit, int *al)
1232 {
1233     int extdatalen = 0;
1234     unsigned char *orig = buf;
1235     unsigned char *ret = buf;
1236 # ifndef OPENSSL_NO_EC
1237     /* See if we support any ECC ciphersuites */
1238     int using_ecc = 0;
1239     if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s)) {
1240         int i;
1241         unsigned long alg_k, alg_a;
1242         STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
1243 
1244         for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++) {
1245             SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
1246 
1247             alg_k = c->algorithm_mkey;
1248             alg_a = c->algorithm_auth;
1249             if ((alg_k & (SSL_kEECDH | SSL_kECDHr | SSL_kECDHe)
1250                  || (alg_a & SSL_aECDSA))) {
1251                 using_ecc = 1;
1252                 break;
1253             }
1254         }
1255     }
1256 # endif
1257 
1258     /* don't add extensions for SSLv3 unless doing secure renegotiation */
1259     if (s->client_version == SSL3_VERSION && !s->s3->send_connection_binding)
1260         return orig;
1261 
1262     ret += 2;
1263 
1264     if (ret >= limit)
1265         return NULL;            /* this really never occurs, but ... */
1266 
1267     if (s->tlsext_hostname != NULL) {
1268         /* Add TLS extension servername to the Client Hello message */
1269         size_t size_str;
1270 
1271         /*-
1272          * check for enough space.
1273          * 4 for the servername type and entension length
1274          * 2 for servernamelist length
1275          * 1 for the hostname type
1276          * 2 for hostname length
1277          * + hostname length
1278          */
1279         size_str = strlen(s->tlsext_hostname);
1280         if (CHECKLEN(ret, 9 + size_str, limit))
1281             return NULL;
1282 
1283         /* extension type and length */
1284         s2n(TLSEXT_TYPE_server_name, ret);
1285         s2n(size_str + 5, ret);
1286 
1287         /* length of servername list */
1288         s2n(size_str + 3, ret);
1289 
1290         /* hostname type, length and hostname */
1291         *(ret++) = (unsigned char)TLSEXT_NAMETYPE_host_name;
1292         s2n(size_str, ret);
1293         memcpy(ret, s->tlsext_hostname, size_str);
1294         ret += size_str;
1295     }
1296 
1297     /* Add RI if renegotiating */
1298     if (s->renegotiate) {
1299         int el;
1300 
1301         if (!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0)) {
1302             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1303             return NULL;
1304         }
1305 
1306         if ((limit - ret - 4 - el) < 0)
1307             return NULL;
1308 
1309         s2n(TLSEXT_TYPE_renegotiate, ret);
1310         s2n(el, ret);
1311 
1312         if (!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el)) {
1313             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1314             return NULL;
1315         }
1316 
1317         ret += el;
1318     }
1319 # ifndef OPENSSL_NO_SRP
1320     /* Add SRP username if there is one */
1321     if (s->srp_ctx.login != NULL) { /* Add TLS extension SRP username to the
1322                                      * Client Hello message */
1323 
1324         size_t login_len = strlen(s->srp_ctx.login);
1325         if (login_len > 255 || login_len == 0) {
1326             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1327             return NULL;
1328         }
1329 
1330         /*-
1331          * check for enough space.
1332          * 4 for the srp type type and entension length
1333          * 1 for the srp user identity
1334          * + srp user identity length
1335          */
1336         if (CHECKLEN(ret, 5 + login_len, limit))
1337             return NULL;
1338 
1339         /* fill in the extension */
1340         s2n(TLSEXT_TYPE_srp, ret);
1341         s2n(login_len + 1, ret);
1342         (*ret++) = (unsigned char)login_len;
1343         memcpy(ret, s->srp_ctx.login, login_len);
1344         ret += login_len;
1345     }
1346 # endif
1347 
1348 # ifndef OPENSSL_NO_EC
1349     if (using_ecc) {
1350         /*
1351          * Add TLS extension ECPointFormats to the ClientHello message
1352          */
1353         const unsigned char *pcurves, *pformats;
1354         size_t num_curves, num_formats, curves_list_len;
1355 
1356         tls1_get_formatlist(s, &pformats, &num_formats);
1357 
1358         if (num_formats > 255) {
1359             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1360             return NULL;
1361         }
1362         /*-
1363          * check for enough space.
1364          * 4 bytes for the ec point formats type and extension length
1365          * 1 byte for the length of the formats
1366          * + formats length
1367          */
1368         if (CHECKLEN(ret, 5 + num_formats, limit))
1369             return NULL;
1370 
1371         s2n(TLSEXT_TYPE_ec_point_formats, ret);
1372         /* The point format list has 1-byte length. */
1373         s2n(num_formats + 1, ret);
1374         *(ret++) = (unsigned char)num_formats;
1375         memcpy(ret, pformats, num_formats);
1376         ret += num_formats;
1377 
1378         /*
1379          * Add TLS extension EllipticCurves to the ClientHello message
1380          */
1381         pcurves = s->tlsext_ellipticcurvelist;
1382         if (!tls1_get_curvelist(s, 0, &pcurves, &num_curves))
1383             return NULL;
1384 
1385         if (num_curves > 65532 / 2) {
1386             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1387             return NULL;
1388         }
1389         curves_list_len = 2 * num_curves;
1390         /*-
1391          * check for enough space.
1392          * 4 bytes for the ec curves type and extension length
1393          * 2 bytes for the curve list length
1394          * + curve list length
1395          */
1396         if (CHECKLEN(ret, 6 + curves_list_len, limit))
1397             return NULL;
1398 
1399         s2n(TLSEXT_TYPE_elliptic_curves, ret);
1400         s2n(curves_list_len + 2, ret);
1401         s2n(curves_list_len, ret);
1402         memcpy(ret, pcurves, curves_list_len);
1403         ret += curves_list_len;
1404     }
1405 # endif                         /* OPENSSL_NO_EC */
1406 
1407     if (!(SSL_get_options(s) & SSL_OP_NO_TICKET)) {
1408         size_t ticklen;
1409         if (!s->new_session && s->session && s->session->tlsext_tick)
1410             ticklen = s->session->tlsext_ticklen;
1411         else if (s->session && s->tlsext_session_ticket &&
1412                  s->tlsext_session_ticket->data) {
1413             ticklen = s->tlsext_session_ticket->length;
1414             s->session->tlsext_tick = OPENSSL_malloc(ticklen);
1415             if (!s->session->tlsext_tick)
1416                 return NULL;
1417             memcpy(s->session->tlsext_tick,
1418                    s->tlsext_session_ticket->data, ticklen);
1419             s->session->tlsext_ticklen = ticklen;
1420         } else
1421             ticklen = 0;
1422         if (ticklen == 0 && s->tlsext_session_ticket &&
1423             s->tlsext_session_ticket->data == NULL)
1424             goto skip_ext;
1425         /*
1426          * Check for enough room 2 for extension type, 2 for len rest for
1427          * ticket
1428          */
1429         if (CHECKLEN(ret, 4 + ticklen, limit))
1430             return NULL;
1431         s2n(TLSEXT_TYPE_session_ticket, ret);
1432         s2n(ticklen, ret);
1433         if (ticklen > 0) {
1434             memcpy(ret, s->session->tlsext_tick, ticklen);
1435             ret += ticklen;
1436         }
1437     }
1438  skip_ext:
1439 
1440     if (SSL_CLIENT_USE_SIGALGS(s)) {
1441         size_t salglen;
1442         const unsigned char *salg;
1443         salglen = tls12_get_psigalgs(s, 1, &salg);
1444 
1445         /*-
1446          * check for enough space.
1447          * 4 bytes for the sigalgs type and extension length
1448          * 2 bytes for the sigalg list length
1449          * + sigalg list length
1450          */
1451         if (CHECKLEN(ret, salglen + 6, limit))
1452             return NULL;
1453         s2n(TLSEXT_TYPE_signature_algorithms, ret);
1454         s2n(salglen + 2, ret);
1455         s2n(salglen, ret);
1456         memcpy(ret, salg, salglen);
1457         ret += salglen;
1458     }
1459 # ifdef TLSEXT_TYPE_opaque_prf_input
1460     if (s->s3->client_opaque_prf_input != NULL) {
1461         size_t col = s->s3->client_opaque_prf_input_len;
1462 
1463         if ((long)(limit - ret - 6 - col < 0))
1464             return NULL;
1465         if (col > 0xFFFD)       /* can't happen */
1466             return NULL;
1467 
1468         s2n(TLSEXT_TYPE_opaque_prf_input, ret);
1469         s2n(col + 2, ret);
1470         s2n(col, ret);
1471         memcpy(ret, s->s3->client_opaque_prf_input, col);
1472         ret += col;
1473     }
1474 # endif
1475 
1476     if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
1477         int i;
1478         size_t extlen, idlen;
1479         int lentmp;
1480         OCSP_RESPID *id;
1481 
1482         idlen = 0;
1483         for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
1484             id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1485             lentmp = i2d_OCSP_RESPID(id, NULL);
1486             if (lentmp <= 0)
1487                 return NULL;
1488             idlen += (size_t)lentmp + 2;
1489         }
1490 
1491         if (s->tlsext_ocsp_exts) {
1492             lentmp = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
1493             if (lentmp < 0)
1494                 return NULL;
1495             extlen = (size_t)lentmp;
1496         } else
1497             extlen = 0;
1498 
1499         if (extlen + idlen > 0xFFF0)
1500             return NULL;
1501         /*
1502          * 2 bytes for status request type
1503          * 2 bytes for status request len
1504          * 1 byte for OCSP request type
1505          * 2 bytes for length of ids
1506          * 2 bytes for length of extensions
1507          * + length of ids
1508          * + length of extensions
1509          */
1510         if (CHECKLEN(ret, 9 + idlen + extlen, limit))
1511             return NULL;
1512 
1513         s2n(TLSEXT_TYPE_status_request, ret);
1514         s2n(extlen + idlen + 5, ret);
1515         *(ret++) = TLSEXT_STATUSTYPE_ocsp;
1516         s2n(idlen, ret);
1517         for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++) {
1518             /* save position of id len */
1519             unsigned char *q = ret;
1520             id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1521             /* skip over id len */
1522             ret += 2;
1523             lentmp = i2d_OCSP_RESPID(id, &ret);
1524             /* write id len */
1525             s2n(lentmp, q);
1526         }
1527         s2n(extlen, ret);
1528         if (extlen > 0)
1529             i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
1530     }
1531 # ifndef OPENSSL_NO_HEARTBEATS
1532     /* Add Heartbeat extension */
1533 
1534     /*-
1535      * check for enough space.
1536      * 4 bytes for the heartbeat ext type and extension length
1537      * 1 byte for the mode
1538      */
1539     if (CHECKLEN(ret, 5, limit))
1540         return NULL;
1541 
1542     s2n(TLSEXT_TYPE_heartbeat, ret);
1543     s2n(1, ret);
1544     /*-
1545      * Set mode:
1546      * 1: peer may send requests
1547      * 2: peer not allowed to send requests
1548      */
1549     if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1550         *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1551     else
1552         *(ret++) = SSL_TLSEXT_HB_ENABLED;
1553 # endif
1554 
1555 # ifndef OPENSSL_NO_NEXTPROTONEG
1556     if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len) {
1557         /*
1558          * The client advertises an emtpy extension to indicate its support
1559          * for Next Protocol Negotiation
1560          */
1561 
1562         /*-
1563          * check for enough space.
1564          * 4 bytes for the NPN ext type and extension length
1565          */
1566         if (CHECKLEN(ret, 4, limit))
1567             return NULL;
1568         s2n(TLSEXT_TYPE_next_proto_neg, ret);
1569         s2n(0, ret);
1570     }
1571 # endif
1572 
1573     if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len) {
1574         /*-
1575          * check for enough space.
1576          * 4 bytes for the ALPN type and extension length
1577          * 2 bytes for the ALPN protocol list length
1578          * + ALPN protocol list length
1579          */
1580         if (CHECKLEN(ret, 6 + s->alpn_client_proto_list_len, limit))
1581             return NULL;
1582         s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
1583         s2n(2 + s->alpn_client_proto_list_len, ret);
1584         s2n(s->alpn_client_proto_list_len, ret);
1585         memcpy(ret, s->alpn_client_proto_list, s->alpn_client_proto_list_len);
1586         ret += s->alpn_client_proto_list_len;
1587         s->cert->alpn_sent = 1;
1588     }
1589 # ifndef OPENSSL_NO_SRTP
1590     if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)) {
1591         int el;
1592 
1593         ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
1594 
1595         /*-
1596          * check for enough space.
1597          * 4 bytes for the SRTP type and extension length
1598          * + SRTP profiles length
1599          */
1600         if (CHECKLEN(ret, 4 + el, limit))
1601             return NULL;
1602 
1603         s2n(TLSEXT_TYPE_use_srtp, ret);
1604         s2n(el, ret);
1605 
1606         if (ssl_add_clienthello_use_srtp_ext(s, ret, &el, el)) {
1607             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1608             return NULL;
1609         }
1610         ret += el;
1611     }
1612 # endif
1613     custom_ext_init(&s->cert->cli_ext);
1614     /* Add custom TLS Extensions to ClientHello */
1615     if (!custom_ext_add(s, 0, &ret, limit, al))
1616         return NULL;
1617 
1618     /*
1619      * Add padding to workaround bugs in F5 terminators. See
1620      * https://tools.ietf.org/html/draft-agl-tls-padding-03 NB: because this
1621      * code works out the length of all existing extensions it MUST always
1622      * appear last.
1623      */
1624     if (s->options & SSL_OP_TLSEXT_PADDING) {
1625         int hlen = ret - (unsigned char *)s->init_buf->data;
1626         /*
1627          * The code in s23_clnt.c to build ClientHello messages includes the
1628          * 5-byte record header in the buffer, while the code in s3_clnt.c
1629          * does not.
1630          */
1631         if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
1632             hlen -= 5;
1633         if (hlen > 0xff && hlen < 0x200) {
1634             hlen = 0x200 - hlen;
1635             if (hlen >= 4)
1636                 hlen -= 4;
1637             else
1638                 hlen = 0;
1639 
1640             /*-
1641              * check for enough space. Strictly speaking we know we've already
1642              * got enough space because to get here the message size is < 0x200,
1643              * but we know that we've allocated far more than that in the buffer
1644              * - but for consistency and robustness we're going to check anyway.
1645              *
1646              * 4 bytes for the padding type and extension length
1647              * + padding length
1648              */
1649             if (CHECKLEN(ret, 4 + hlen, limit))
1650                 return NULL;
1651             s2n(TLSEXT_TYPE_padding, ret);
1652             s2n(hlen, ret);
1653             memset(ret, 0, hlen);
1654             ret += hlen;
1655         }
1656     }
1657 
1658     if ((extdatalen = ret - orig - 2) == 0)
1659         return orig;
1660 
1661     s2n(extdatalen, orig);
1662     return ret;
1663 }
1664 
1665 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf,
1666                                           unsigned char *limit, int *al)
1667 {
1668     int extdatalen = 0;
1669     unsigned char *orig = buf;
1670     unsigned char *ret = buf;
1671 # ifndef OPENSSL_NO_NEXTPROTONEG
1672     int next_proto_neg_seen;
1673 # endif
1674 # ifndef OPENSSL_NO_EC
1675     unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1676     unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1677     int using_ecc = (alg_k & (SSL_kEECDH | SSL_kECDHr | SSL_kECDHe))
1678         || (alg_a & SSL_aECDSA);
1679     using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
1680 # endif
1681     /*
1682      * don't add extensions for SSLv3, unless doing secure renegotiation
1683      */
1684     if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
1685         return orig;
1686 
1687     ret += 2;
1688     if (ret >= limit)
1689         return NULL;            /* this really never occurs, but ... */
1690 
1691     if (!s->hit && s->servername_done == 1
1692         && s->session->tlsext_hostname != NULL) {
1693         if ((long)(limit - ret - 4) < 0)
1694             return NULL;
1695 
1696         s2n(TLSEXT_TYPE_server_name, ret);
1697         s2n(0, ret);
1698     }
1699 
1700     if (s->s3->send_connection_binding) {
1701         int el;
1702 
1703         if (!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0)) {
1704             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1705             return NULL;
1706         }
1707 
1708         /*-
1709          * check for enough space.
1710          * 4 bytes for the reneg type and extension length
1711          * + reneg data length
1712          */
1713         if (CHECKLEN(ret, 4 + el, limit))
1714             return NULL;
1715 
1716         s2n(TLSEXT_TYPE_renegotiate, ret);
1717         s2n(el, ret);
1718 
1719         if (!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el)) {
1720             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1721             return NULL;
1722         }
1723 
1724         ret += el;
1725     }
1726 # ifndef OPENSSL_NO_EC
1727     if (using_ecc) {
1728         const unsigned char *plist;
1729         size_t plistlen;
1730         /*
1731          * Add TLS extension ECPointFormats to the ServerHello message
1732          */
1733 
1734         tls1_get_formatlist(s, &plist, &plistlen);
1735 
1736         if (plistlen > 255) {
1737             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1738             return NULL;
1739         }
1740 
1741         /*-
1742          * check for enough space.
1743          * 4 bytes for the ec points format type and extension length
1744          * 1 byte for the points format list length
1745          * + length of points format list
1746          */
1747         if (CHECKLEN(ret, 5 + plistlen, limit))
1748             return NULL;
1749 
1750         s2n(TLSEXT_TYPE_ec_point_formats, ret);
1751         s2n(plistlen + 1, ret);
1752         *(ret++) = (unsigned char)plistlen;
1753         memcpy(ret, plist, plistlen);
1754         ret += plistlen;
1755 
1756     }
1757     /*
1758      * Currently the server should not respond with a SupportedCurves
1759      * extension
1760      */
1761 # endif                         /* OPENSSL_NO_EC */
1762 
1763     if (s->tlsext_ticket_expected && !(SSL_get_options(s) & SSL_OP_NO_TICKET)) {
1764         /*-
1765          * check for enough space.
1766          * 4 bytes for the Ticket type and extension length
1767          */
1768         if (CHECKLEN(ret, 4, limit))
1769             return NULL;
1770         s2n(TLSEXT_TYPE_session_ticket, ret);
1771         s2n(0, ret);
1772     } else {
1773         /* if we don't add the above TLSEXT, we can't add a session ticket later */
1774         s->tlsext_ticket_expected = 0;
1775     }
1776 
1777     if (s->tlsext_status_expected) {
1778         /*-
1779          * check for enough space.
1780          * 4 bytes for the Status request type and extension length
1781          */
1782         if (CHECKLEN(ret, 4, limit))
1783             return NULL;
1784         s2n(TLSEXT_TYPE_status_request, ret);
1785         s2n(0, ret);
1786     }
1787 # ifdef TLSEXT_TYPE_opaque_prf_input
1788     if (s->s3->server_opaque_prf_input != NULL) {
1789         size_t sol = s->s3->server_opaque_prf_input_len;
1790 
1791         if ((long)(limit - ret - 6 - sol) < 0)
1792             return NULL;
1793         if (sol > 0xFFFD)       /* can't happen */
1794             return NULL;
1795 
1796         s2n(TLSEXT_TYPE_opaque_prf_input, ret);
1797         s2n(sol + 2, ret);
1798         s2n(sol, ret);
1799         memcpy(ret, s->s3->server_opaque_prf_input, sol);
1800         ret += sol;
1801     }
1802 # endif
1803 
1804 # ifndef OPENSSL_NO_SRTP
1805     if (SSL_IS_DTLS(s) && s->srtp_profile) {
1806         int el;
1807 
1808         ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
1809 
1810         /*-
1811          * check for enough space.
1812          * 4 bytes for the SRTP profiles type and extension length
1813          * + length of the SRTP profiles list
1814          */
1815         if (CHECKLEN(ret, 4 + el, limit))
1816             return NULL;
1817 
1818         s2n(TLSEXT_TYPE_use_srtp, ret);
1819         s2n(el, ret);
1820 
1821         if (ssl_add_serverhello_use_srtp_ext(s, ret, &el, el)) {
1822             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1823             return NULL;
1824         }
1825         ret += el;
1826     }
1827 # endif
1828 
1829     if (((s->s3->tmp.new_cipher->id & 0xFFFF) == 0x80
1830          || (s->s3->tmp.new_cipher->id & 0xFFFF) == 0x81)
1831         && (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG)) {
1832         const unsigned char cryptopro_ext[36] = {
1833             0xfd, 0xe8,         /* 65000 */
1834             0x00, 0x20,         /* 32 bytes length */
1835             0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85,
1836             0x03, 0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06,
1837             0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08,
1838             0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17
1839         };
1840 
1841         /* check for enough space. */
1842         if (CHECKLEN(ret, sizeof(cryptopro_ext), limit))
1843             return NULL;
1844         memcpy(ret, cryptopro_ext, sizeof(cryptopro_ext));
1845         ret += sizeof(cryptopro_ext);
1846 
1847     }
1848 # ifndef OPENSSL_NO_HEARTBEATS
1849     /* Add Heartbeat extension if we've received one */
1850     if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) {
1851         /*-
1852          * check for enough space.
1853          * 4 bytes for the Heartbeat type and extension length
1854          * 1 byte for the mode
1855          */
1856         if (CHECKLEN(ret, 5, limit))
1857             return NULL;
1858         s2n(TLSEXT_TYPE_heartbeat, ret);
1859         s2n(1, ret);
1860         /*-
1861          * Set mode:
1862          * 1: peer may send requests
1863          * 2: peer not allowed to send requests
1864          */
1865         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1866             *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1867         else
1868             *(ret++) = SSL_TLSEXT_HB_ENABLED;
1869 
1870     }
1871 # endif
1872 
1873 # ifndef OPENSSL_NO_NEXTPROTONEG
1874     next_proto_neg_seen = s->s3->next_proto_neg_seen;
1875     s->s3->next_proto_neg_seen = 0;
1876     if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb) {
1877         const unsigned char *npa;
1878         unsigned int npalen;
1879         int r;
1880 
1881         r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen,
1882                                               s->
1883                                               ctx->next_protos_advertised_cb_arg);
1884         if (r == SSL_TLSEXT_ERR_OK) {
1885             /*-
1886              * check for enough space.
1887              * 4 bytes for the NPN type and extension length
1888              * + length of protocols list
1889              */
1890             if (CHECKLEN(ret, 4 + npalen, limit))
1891                 return NULL;
1892             s2n(TLSEXT_TYPE_next_proto_neg, ret);
1893             s2n(npalen, ret);
1894             memcpy(ret, npa, npalen);
1895             ret += npalen;
1896             s->s3->next_proto_neg_seen = 1;
1897         }
1898     }
1899 # endif
1900     if (!custom_ext_add(s, 1, &ret, limit, al))
1901         return NULL;
1902 
1903     if (s->s3->alpn_selected) {
1904         const unsigned char *selected = s->s3->alpn_selected;
1905         size_t len = s->s3->alpn_selected_len;
1906 
1907         /*-
1908          * check for enough space.
1909          * 4 bytes for the ALPN type and extension length
1910          * 2 bytes for ALPN data length
1911          * 1 byte for selected protocol length
1912          * + length of the selected protocol
1913          */
1914         if (CHECKLEN(ret, 7 + len, limit))
1915             return NULL;
1916         s2n(TLSEXT_TYPE_application_layer_protocol_negotiation, ret);
1917         s2n(3 + len, ret);
1918         s2n(1 + len, ret);
1919         *ret++ = (unsigned char)len;
1920         memcpy(ret, selected, len);
1921         ret += len;
1922     }
1923 
1924     if ((extdatalen = ret - orig - 2) == 0)
1925         return orig;
1926 
1927     s2n(extdatalen, orig);
1928     return ret;
1929 }
1930 
1931 # ifndef OPENSSL_NO_EC
1932 /*-
1933  * ssl_check_for_safari attempts to fingerprint Safari using OS X
1934  * SecureTransport using the TLS extension block in |d|, of length |n|.
1935  * Safari, since 10.6, sends exactly these extensions, in this order:
1936  *   SNI,
1937  *   elliptic_curves
1938  *   ec_point_formats
1939  *
1940  * We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
1941  * but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
1942  * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
1943  * 10.8..10.8.3 (which don't work).
1944  */
1945 static void ssl_check_for_safari(SSL *s, const unsigned char *data,
1946                                  const unsigned char *limit)
1947 {
1948     unsigned short type, size;
1949     static const unsigned char kSafariExtensionsBlock[] = {
1950         0x00, 0x0a,             /* elliptic_curves extension */
1951         0x00, 0x08,             /* 8 bytes */
1952         0x00, 0x06,             /* 6 bytes of curve ids */
1953         0x00, 0x17,             /* P-256 */
1954         0x00, 0x18,             /* P-384 */
1955         0x00, 0x19,             /* P-521 */
1956 
1957         0x00, 0x0b,             /* ec_point_formats */
1958         0x00, 0x02,             /* 2 bytes */
1959         0x01,                   /* 1 point format */
1960         0x00,                   /* uncompressed */
1961     };
1962 
1963     /* The following is only present in TLS 1.2 */
1964     static const unsigned char kSafariTLS12ExtensionsBlock[] = {
1965         0x00, 0x0d,             /* signature_algorithms */
1966         0x00, 0x0c,             /* 12 bytes */
1967         0x00, 0x0a,             /* 10 bytes */
1968         0x05, 0x01,             /* SHA-384/RSA */
1969         0x04, 0x01,             /* SHA-256/RSA */
1970         0x02, 0x01,             /* SHA-1/RSA */
1971         0x04, 0x03,             /* SHA-256/ECDSA */
1972         0x02, 0x03,             /* SHA-1/ECDSA */
1973     };
1974 
1975     if (limit - data <= 2)
1976         return;
1977     data += 2;
1978 
1979     if (limit - data < 4)
1980         return;
1981     n2s(data, type);
1982     n2s(data, size);
1983 
1984     if (type != TLSEXT_TYPE_server_name)
1985         return;
1986 
1987     if (limit - data < size)
1988         return;
1989     data += size;
1990 
1991     if (TLS1_get_client_version(s) >= TLS1_2_VERSION) {
1992         const size_t len1 = sizeof(kSafariExtensionsBlock);
1993         const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
1994 
1995         if (limit - data != (int)(len1 + len2))
1996             return;
1997         if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
1998             return;
1999         if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
2000             return;
2001     } else {
2002         const size_t len = sizeof(kSafariExtensionsBlock);
2003 
2004         if (limit - data != (int)(len))
2005             return;
2006         if (memcmp(data, kSafariExtensionsBlock, len) != 0)
2007             return;
2008     }
2009 
2010     s->s3->is_probably_safari = 1;
2011 }
2012 # endif                         /* !OPENSSL_NO_EC */
2013 
2014 /*
2015  * tls1_alpn_handle_client_hello is called to save the ALPN extension in a
2016  * ClientHello.  data: the contents of the extension, not including the type
2017  * and length.  data_len: the number of bytes in |data| al: a pointer to the
2018  * alert value to send in the event of a non-zero return.  returns: 0 on
2019  * success.
2020  */
2021 static int tls1_alpn_handle_client_hello(SSL *s, const unsigned char *data,
2022                                          unsigned data_len, int *al)
2023 {
2024     unsigned i;
2025     unsigned proto_len;
2026 
2027     if (data_len < 2)
2028         goto parse_error;
2029 
2030     /*
2031      * data should contain a uint16 length followed by a series of 8-bit,
2032      * length-prefixed strings.
2033      */
2034     i = ((unsigned)data[0]) << 8 | ((unsigned)data[1]);
2035     data_len -= 2;
2036     data += 2;
2037     if (data_len != i)
2038         goto parse_error;
2039 
2040     if (data_len < 2)
2041         goto parse_error;
2042 
2043     for (i = 0; i < data_len;) {
2044         proto_len = data[i];
2045         i++;
2046 
2047         if (proto_len == 0)
2048             goto parse_error;
2049 
2050         if (i + proto_len < i || i + proto_len > data_len)
2051             goto parse_error;
2052 
2053         i += proto_len;
2054     }
2055 
2056     if (s->cert->alpn_proposed != NULL)
2057         OPENSSL_free(s->cert->alpn_proposed);
2058     s->cert->alpn_proposed = OPENSSL_malloc(data_len);
2059     if (s->cert->alpn_proposed == NULL) {
2060         *al = SSL_AD_INTERNAL_ERROR;
2061         return -1;
2062     }
2063     memcpy(s->cert->alpn_proposed, data, data_len);
2064     s->cert->alpn_proposed_len = data_len;
2065     return 0;
2066 
2067  parse_error:
2068     *al = SSL_AD_DECODE_ERROR;
2069     return -1;
2070 }
2071 
2072 /*
2073  * Process the ALPN extension in a ClientHello.
2074  * al: a pointer to the alert value to send in the event of a failure.
2075  * returns 1 on success, 0 on failure: al set only on failure
2076  */
2077 static int tls1_alpn_handle_client_hello_late(SSL *s, int *al)
2078 {
2079     const unsigned char *selected = NULL;
2080     unsigned char selected_len = 0;
2081 
2082     if (s->ctx->alpn_select_cb != NULL && s->cert->alpn_proposed != NULL) {
2083         int r = s->ctx->alpn_select_cb(s, &selected, &selected_len,
2084                                        s->cert->alpn_proposed,
2085                                        s->cert->alpn_proposed_len,
2086                                        s->ctx->alpn_select_cb_arg);
2087 
2088         if (r == SSL_TLSEXT_ERR_OK) {
2089             OPENSSL_free(s->s3->alpn_selected);
2090             s->s3->alpn_selected = OPENSSL_malloc(selected_len);
2091             if (s->s3->alpn_selected == NULL) {
2092                 *al = SSL_AD_INTERNAL_ERROR;
2093                 return 0;
2094             }
2095             memcpy(s->s3->alpn_selected, selected, selected_len);
2096             s->s3->alpn_selected_len = selected_len;
2097 # ifndef OPENSSL_NO_NEXTPROTONEG
2098             /* ALPN takes precedence over NPN. */
2099             s->s3->next_proto_neg_seen = 0;
2100 # endif
2101         }
2102     }
2103 
2104     return 1;
2105 }
2106 
2107 static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p,
2108                                        unsigned char *limit, int *al)
2109 {
2110     unsigned short type;
2111     unsigned short size;
2112     unsigned short len;
2113     unsigned char *data = *p;
2114     int renegotiate_seen = 0;
2115 
2116     s->servername_done = 0;
2117     s->tlsext_status_type = -1;
2118 # ifndef OPENSSL_NO_NEXTPROTONEG
2119     s->s3->next_proto_neg_seen = 0;
2120 # endif
2121 
2122     if (s->s3->alpn_selected) {
2123         OPENSSL_free(s->s3->alpn_selected);
2124         s->s3->alpn_selected = NULL;
2125     }
2126     s->s3->alpn_selected_len = 0;
2127     if (s->cert->alpn_proposed) {
2128         OPENSSL_free(s->cert->alpn_proposed);
2129         s->cert->alpn_proposed = NULL;
2130     }
2131     s->cert->alpn_proposed_len = 0;
2132 # ifndef OPENSSL_NO_HEARTBEATS
2133     s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
2134                              SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
2135 # endif
2136 
2137 # ifndef OPENSSL_NO_EC
2138     if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
2139         ssl_check_for_safari(s, data, limit);
2140 # endif                         /* !OPENSSL_NO_EC */
2141 
2142     /* Clear any signature algorithms extension received */
2143     if (s->cert->peer_sigalgs) {
2144         OPENSSL_free(s->cert->peer_sigalgs);
2145         s->cert->peer_sigalgs = NULL;
2146     }
2147 # ifndef OPENSSL_NO_SRP
2148     if (s->srp_ctx.login != NULL) {
2149         OPENSSL_free(s->srp_ctx.login);
2150         s->srp_ctx.login = NULL;
2151     }
2152 # endif
2153 
2154     s->srtp_profile = NULL;
2155 
2156     if (data == limit)
2157         goto ri_check;
2158 
2159     if (limit - data < 2)
2160         goto err;
2161 
2162     n2s(data, len);
2163 
2164     if (limit - data != len)
2165         goto err;
2166 
2167     while (limit - data >= 4) {
2168         n2s(data, type);
2169         n2s(data, size);
2170 
2171         if (limit - data < size)
2172             goto err;
2173 # if 0
2174         fprintf(stderr, "Received extension type %d size %d\n", type, size);
2175 # endif
2176         if (s->tlsext_debug_cb)
2177             s->tlsext_debug_cb(s, 0, type, data, size, s->tlsext_debug_arg);
2178 /*-
2179  * The servername extension is treated as follows:
2180  *
2181  * - Only the hostname type is supported with a maximum length of 255.
2182  * - The servername is rejected if too long or if it contains zeros,
2183  *   in which case an fatal alert is generated.
2184  * - The servername field is maintained together with the session cache.
2185  * - When a session is resumed, the servername call back invoked in order
2186  *   to allow the application to position itself to the right context.
2187  * - The servername is acknowledged if it is new for a session or when
2188  *   it is identical to a previously used for the same session.
2189  *   Applications can control the behaviour.  They can at any time
2190  *   set a 'desirable' servername for a new SSL object. This can be the
2191  *   case for example with HTTPS when a Host: header field is received and
2192  *   a renegotiation is requested. In this case, a possible servername
2193  *   presented in the new client hello is only acknowledged if it matches
2194  *   the value of the Host: field.
2195  * - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
2196  *   if they provide for changing an explicit servername context for the
2197  *   session, i.e. when the session has been established with a servername
2198  *   extension.
2199  * - On session reconnect, the servername extension may be absent.
2200  *
2201  */
2202 
2203         if (type == TLSEXT_TYPE_server_name) {
2204             unsigned char *sdata;
2205             int servname_type;
2206             int dsize;
2207 
2208             if (size < 2)
2209                 goto err;
2210             n2s(data, dsize);
2211             size -= 2;
2212             if (dsize > size)
2213                 goto err;
2214 
2215             sdata = data;
2216             while (dsize > 3) {
2217                 servname_type = *(sdata++);
2218                 n2s(sdata, len);
2219                 dsize -= 3;
2220 
2221                 if (len > dsize)
2222                     goto err;
2223 
2224                 if (s->servername_done == 0)
2225                     switch (servname_type) {
2226                     case TLSEXT_NAMETYPE_host_name:
2227                         if (!s->hit) {
2228                             if (s->session->tlsext_hostname)
2229                                 goto err;
2230 
2231                             if (len > TLSEXT_MAXLEN_host_name) {
2232                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
2233                                 return 0;
2234                             }
2235                             if ((s->session->tlsext_hostname =
2236                                  OPENSSL_malloc(len + 1)) == NULL) {
2237                                 *al = TLS1_AD_INTERNAL_ERROR;
2238                                 return 0;
2239                             }
2240                             memcpy(s->session->tlsext_hostname, sdata, len);
2241                             s->session->tlsext_hostname[len] = '\0';
2242                             if (strlen(s->session->tlsext_hostname) != len) {
2243                                 OPENSSL_free(s->session->tlsext_hostname);
2244                                 s->session->tlsext_hostname = NULL;
2245                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
2246                                 return 0;
2247                             }
2248                             s->servername_done = 1;
2249 
2250                         } else
2251                             s->servername_done = s->session->tlsext_hostname
2252                                 && strlen(s->session->tlsext_hostname) == len
2253                                 && strncmp(s->session->tlsext_hostname,
2254                                            (char *)sdata, len) == 0;
2255 
2256                         break;
2257 
2258                     default:
2259                         break;
2260                     }
2261 
2262                 dsize -= len;
2263             }
2264             if (dsize != 0)
2265                 goto err;
2266 
2267         }
2268 # ifndef OPENSSL_NO_SRP
2269         else if (type == TLSEXT_TYPE_srp) {
2270             if (size == 0 || ((len = data[0])) != (size - 1))
2271                 goto err;
2272             if (s->srp_ctx.login != NULL)
2273                 goto err;
2274             if ((s->srp_ctx.login = OPENSSL_malloc(len + 1)) == NULL)
2275                 return -1;
2276             memcpy(s->srp_ctx.login, &data[1], len);
2277             s->srp_ctx.login[len] = '\0';
2278 
2279             if (strlen(s->srp_ctx.login) != len)
2280                 goto err;
2281         }
2282 # endif
2283 
2284 # ifndef OPENSSL_NO_EC
2285         else if (type == TLSEXT_TYPE_ec_point_formats) {
2286             unsigned char *sdata = data;
2287             int ecpointformatlist_length;
2288 
2289             if (size == 0)
2290                 goto err;
2291 
2292             ecpointformatlist_length = *(sdata++);
2293             if (ecpointformatlist_length != size - 1 ||
2294                 ecpointformatlist_length < 1)
2295                 goto err;
2296             if (!s->hit) {
2297                 if (s->session->tlsext_ecpointformatlist) {
2298                     OPENSSL_free(s->session->tlsext_ecpointformatlist);
2299                     s->session->tlsext_ecpointformatlist = NULL;
2300                 }
2301                 s->session->tlsext_ecpointformatlist_length = 0;
2302                 if ((s->session->tlsext_ecpointformatlist =
2303                      OPENSSL_malloc(ecpointformatlist_length)) == NULL) {
2304                     *al = TLS1_AD_INTERNAL_ERROR;
2305                     return 0;
2306                 }
2307                 s->session->tlsext_ecpointformatlist_length =
2308                     ecpointformatlist_length;
2309                 memcpy(s->session->tlsext_ecpointformatlist, sdata,
2310                        ecpointformatlist_length);
2311             }
2312 #  if 0
2313             fprintf(stderr,
2314                     "ssl_parse_clienthello_tlsext s->session->tlsext_ecpointformatlist (length=%i) ",
2315                     s->session->tlsext_ecpointformatlist_length);
2316             sdata = s->session->tlsext_ecpointformatlist;
2317             for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2318                 fprintf(stderr, "%i ", *(sdata++));
2319             fprintf(stderr, "\n");
2320 #  endif
2321         } else if (type == TLSEXT_TYPE_elliptic_curves) {
2322             unsigned char *sdata = data;
2323             int ellipticcurvelist_length = (*(sdata++) << 8);
2324             ellipticcurvelist_length += (*(sdata++));
2325 
2326             if (ellipticcurvelist_length != size - 2 ||
2327                 ellipticcurvelist_length < 1 ||
2328                 /* Each NamedCurve is 2 bytes. */
2329                 ellipticcurvelist_length & 1)
2330                     goto err;
2331 
2332             if (!s->hit) {
2333                 if (s->session->tlsext_ellipticcurvelist)
2334                     goto err;
2335 
2336                 s->session->tlsext_ellipticcurvelist_length = 0;
2337                 if ((s->session->tlsext_ellipticcurvelist =
2338                      OPENSSL_malloc(ellipticcurvelist_length)) == NULL) {
2339                     *al = TLS1_AD_INTERNAL_ERROR;
2340                     return 0;
2341                 }
2342                 s->session->tlsext_ellipticcurvelist_length =
2343                     ellipticcurvelist_length;
2344                 memcpy(s->session->tlsext_ellipticcurvelist, sdata,
2345                        ellipticcurvelist_length);
2346             }
2347 #  if 0
2348             fprintf(stderr,
2349                     "ssl_parse_clienthello_tlsext s->session->tlsext_ellipticcurvelist (length=%i) ",
2350                     s->session->tlsext_ellipticcurvelist_length);
2351             sdata = s->session->tlsext_ellipticcurvelist;
2352             for (i = 0; i < s->session->tlsext_ellipticcurvelist_length; i++)
2353                 fprintf(stderr, "%i ", *(sdata++));
2354             fprintf(stderr, "\n");
2355 #  endif
2356         }
2357 # endif                         /* OPENSSL_NO_EC */
2358 # ifdef TLSEXT_TYPE_opaque_prf_input
2359         else if (type == TLSEXT_TYPE_opaque_prf_input) {
2360             unsigned char *sdata = data;
2361 
2362             if (size < 2) {
2363                 *al = SSL_AD_DECODE_ERROR;
2364                 return 0;
2365             }
2366             n2s(sdata, s->s3->client_opaque_prf_input_len);
2367             if (s->s3->client_opaque_prf_input_len != size - 2) {
2368                 *al = SSL_AD_DECODE_ERROR;
2369                 return 0;
2370             }
2371 
2372             if (s->s3->client_opaque_prf_input != NULL) {
2373                 /* shouldn't really happen */
2374                 OPENSSL_free(s->s3->client_opaque_prf_input);
2375             }
2376 
2377             /* dummy byte just to get non-NULL */
2378             if (s->s3->client_opaque_prf_input_len == 0)
2379                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1);
2380             else
2381                 s->s3->client_opaque_prf_input =
2382                     BUF_memdup(sdata, s->s3->client_opaque_prf_input_len);
2383             if (s->s3->client_opaque_prf_input == NULL) {
2384                 *al = TLS1_AD_INTERNAL_ERROR;
2385                 return 0;
2386             }
2387         }
2388 # endif
2389         else if (type == TLSEXT_TYPE_session_ticket) {
2390             if (s->tls_session_ticket_ext_cb &&
2391                 !s->tls_session_ticket_ext_cb(s, data, size,
2392                                               s->tls_session_ticket_ext_cb_arg))
2393             {
2394                 *al = TLS1_AD_INTERNAL_ERROR;
2395                 return 0;
2396             }
2397         } else if (type == TLSEXT_TYPE_renegotiate) {
2398             if (!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
2399                 return 0;
2400             renegotiate_seen = 1;
2401         } else if (type == TLSEXT_TYPE_signature_algorithms) {
2402             int dsize;
2403             if (s->cert->peer_sigalgs || size < 2)
2404                 goto err;
2405             n2s(data, dsize);
2406             size -= 2;
2407             if (dsize != size || dsize & 1 || !dsize)
2408                 goto err;
2409             if (!tls1_save_sigalgs(s, data, dsize))
2410                 goto err;
2411         } else if (type == TLSEXT_TYPE_status_request) {
2412 
2413             if (size < 5)
2414                 goto err;
2415 
2416             s->tlsext_status_type = *data++;
2417             size--;
2418             if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp) {
2419                 const unsigned char *sdata;
2420                 int dsize;
2421                 /* Read in responder_id_list */
2422                 n2s(data, dsize);
2423                 size -= 2;
2424                 if (dsize > size)
2425                     goto err;
2426 
2427                 /*
2428                  * We remove any OCSP_RESPIDs from a previous handshake
2429                  * to prevent unbounded memory growth - CVE-2016-6304
2430                  */
2431                 sk_OCSP_RESPID_pop_free(s->tlsext_ocsp_ids,
2432                                         OCSP_RESPID_free);
2433                 if (dsize > 0) {
2434                     s->tlsext_ocsp_ids = sk_OCSP_RESPID_new_null();
2435                     if (s->tlsext_ocsp_ids == NULL) {
2436                         *al = SSL_AD_INTERNAL_ERROR;
2437                         return 0;
2438                     }
2439                 } else {
2440                     s->tlsext_ocsp_ids = NULL;
2441                 }
2442 
2443                 while (dsize > 0) {
2444                     OCSP_RESPID *id;
2445                     int idsize;
2446                     if (dsize < 4)
2447                         goto err;
2448                     n2s(data, idsize);
2449                     dsize -= 2 + idsize;
2450                     size -= 2 + idsize;
2451                     if (dsize < 0)
2452                         goto err;
2453                     sdata = data;
2454                     data += idsize;
2455                     id = d2i_OCSP_RESPID(NULL, &sdata, idsize);
2456                     if (!id)
2457                         goto err;
2458                     if (data != sdata) {
2459                         OCSP_RESPID_free(id);
2460                         goto err;
2461                     }
2462                     if (!sk_OCSP_RESPID_push(s->tlsext_ocsp_ids, id)) {
2463                         OCSP_RESPID_free(id);
2464                         *al = SSL_AD_INTERNAL_ERROR;
2465                         return 0;
2466                     }
2467                 }
2468 
2469                 /* Read in request_extensions */
2470                 if (size < 2)
2471                     goto err;
2472                 n2s(data, dsize);
2473                 size -= 2;
2474                 if (dsize != size)
2475                     goto err;
2476                 sdata = data;
2477                 if (dsize > 0) {
2478                     if (s->tlsext_ocsp_exts) {
2479                         sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
2480                                                    X509_EXTENSION_free);
2481                     }
2482 
2483                     s->tlsext_ocsp_exts =
2484                         d2i_X509_EXTENSIONS(NULL, &sdata, dsize);
2485                     if (!s->tlsext_ocsp_exts || (data + dsize != sdata))
2486                         goto err;
2487                 }
2488             }
2489             /*
2490              * We don't know what to do with any other type * so ignore it.
2491              */
2492             else
2493                 s->tlsext_status_type = -1;
2494         }
2495 # ifndef OPENSSL_NO_HEARTBEATS
2496         else if (type == TLSEXT_TYPE_heartbeat) {
2497             switch (data[0]) {
2498             case 0x01:         /* Client allows us to send HB requests */
2499                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2500                 break;
2501             case 0x02:         /* Client doesn't accept HB requests */
2502                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2503                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2504                 break;
2505             default:
2506                 *al = SSL_AD_ILLEGAL_PARAMETER;
2507                 return 0;
2508             }
2509         }
2510 # endif
2511 # ifndef OPENSSL_NO_NEXTPROTONEG
2512         else if (type == TLSEXT_TYPE_next_proto_neg &&
2513                  s->s3->tmp.finish_md_len == 0) {
2514             /*-
2515              * We shouldn't accept this extension on a
2516              * renegotiation.
2517              *
2518              * s->new_session will be set on renegotiation, but we
2519              * probably shouldn't rely that it couldn't be set on
2520              * the initial renegotation too in certain cases (when
2521              * there's some other reason to disallow resuming an
2522              * earlier session -- the current code won't be doing
2523              * anything like that, but this might change).
2524              *
2525              * A valid sign that there's been a previous handshake
2526              * in this connection is if s->s3->tmp.finish_md_len >
2527              * 0.  (We are talking about a check that will happen
2528              * in the Hello protocol round, well before a new
2529              * Finished message could have been computed.)
2530              */
2531             s->s3->next_proto_neg_seen = 1;
2532         }
2533 # endif
2534 
2535         else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
2536                  s->s3->tmp.finish_md_len == 0) {
2537             if (tls1_alpn_handle_client_hello(s, data, size, al) != 0)
2538                 return 0;
2539         }
2540 
2541         /* session ticket processed earlier */
2542 # ifndef OPENSSL_NO_SRTP
2543         else if (SSL_IS_DTLS(s) && SSL_get_srtp_profiles(s)
2544                  && type == TLSEXT_TYPE_use_srtp) {
2545             if (ssl_parse_clienthello_use_srtp_ext(s, data, size, al))
2546                 return 0;
2547         }
2548 # endif
2549 
2550         data += size;
2551     }
2552 
2553     /* Spurious data on the end */
2554     if (data != limit)
2555         goto err;
2556 
2557     *p = data;
2558 
2559  ri_check:
2560 
2561     /* Need RI if renegotiating */
2562 
2563     if (!renegotiate_seen && s->renegotiate &&
2564         !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
2565         *al = SSL_AD_HANDSHAKE_FAILURE;
2566         SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
2567                SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2568         return 0;
2569     }
2570 
2571     return 1;
2572 err:
2573     *al = SSL_AD_DECODE_ERROR;
2574     return 0;
2575 }
2576 
2577 /*
2578  * Parse any custom extensions found.  "data" is the start of the extension data
2579  * and "limit" is the end of the record. TODO: add strict syntax checking.
2580  */
2581 
2582 static int ssl_scan_clienthello_custom_tlsext(SSL *s,
2583                                               const unsigned char *data,
2584                                               const unsigned char *limit,
2585                                               int *al)
2586 {
2587     unsigned short type, size, len;
2588     /* If resumed session or no custom extensions nothing to do */
2589     if (s->hit || s->cert->srv_ext.meths_count == 0)
2590         return 1;
2591 
2592     if (limit - data <= 2)
2593         return 1;
2594     n2s(data, len);
2595 
2596     if (limit - data < len)
2597         return 1;
2598 
2599     while (limit - data >= 4) {
2600         n2s(data, type);
2601         n2s(data, size);
2602 
2603         if (limit - data < size)
2604             return 1;
2605         if (custom_ext_parse(s, 1 /* server */ , type, data, size, al) <= 0)
2606             return 0;
2607 
2608         data += size;
2609     }
2610 
2611     return 1;
2612 }
2613 
2614 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p,
2615                                  unsigned char *limit)
2616 {
2617     int al = -1;
2618     unsigned char *ptmp = *p;
2619     /*
2620      * Internally supported extensions are parsed first so SNI can be handled
2621      * before custom extensions. An application processing SNI will typically
2622      * switch the parent context using SSL_set_SSL_CTX and custom extensions
2623      * need to be handled by the new SSL_CTX structure.
2624      */
2625     if (ssl_scan_clienthello_tlsext(s, p, limit, &al) <= 0) {
2626         ssl3_send_alert(s, SSL3_AL_FATAL, al);
2627         return 0;
2628     }
2629 
2630     if (ssl_check_clienthello_tlsext_early(s) <= 0) {
2631         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT, SSL_R_CLIENTHELLO_TLSEXT);
2632         return 0;
2633     }
2634 
2635     custom_ext_init(&s->cert->srv_ext);
2636     if (ssl_scan_clienthello_custom_tlsext(s, ptmp, limit, &al) <= 0) {
2637         ssl3_send_alert(s, SSL3_AL_FATAL, al);
2638         return 0;
2639     }
2640 
2641     return 1;
2642 }
2643 
2644 # ifndef OPENSSL_NO_NEXTPROTONEG
2645 /*
2646  * ssl_next_proto_validate validates a Next Protocol Negotiation block. No
2647  * elements of zero length are allowed and the set of elements must exactly
2648  * fill the length of the block.
2649  */
2650 static char ssl_next_proto_validate(unsigned char *d, unsigned len)
2651 {
2652     unsigned int off = 0;
2653 
2654     while (off < len) {
2655         if (d[off] == 0)
2656             return 0;
2657         off += d[off];
2658         off++;
2659     }
2660 
2661     return off == len;
2662 }
2663 # endif
2664 
2665 static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p,
2666                                        unsigned char *d, int n, int *al)
2667 {
2668     unsigned short length;
2669     unsigned short type;
2670     unsigned short size;
2671     unsigned char *data = *p;
2672     int tlsext_servername = 0;
2673     int renegotiate_seen = 0;
2674 
2675 # ifndef OPENSSL_NO_NEXTPROTONEG
2676     s->s3->next_proto_neg_seen = 0;
2677 # endif
2678     s->tlsext_ticket_expected = 0;
2679 
2680     if (s->s3->alpn_selected) {
2681         OPENSSL_free(s->s3->alpn_selected);
2682         s->s3->alpn_selected = NULL;
2683     }
2684 # ifndef OPENSSL_NO_HEARTBEATS
2685     s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
2686                              SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
2687 # endif
2688 
2689     if ((d + n) - data <= 2)
2690         goto ri_check;
2691 
2692     n2s(data, length);
2693     if ((d + n) - data != length) {
2694         *al = SSL_AD_DECODE_ERROR;
2695         return 0;
2696     }
2697 
2698     while ((d + n) - data >= 4) {
2699         n2s(data, type);
2700         n2s(data, size);
2701 
2702         if ((d + n) - data < size)
2703             goto ri_check;
2704 
2705         if (s->tlsext_debug_cb)
2706             s->tlsext_debug_cb(s, 1, type, data, size, s->tlsext_debug_arg);
2707 
2708         if (type == TLSEXT_TYPE_server_name) {
2709             if (s->tlsext_hostname == NULL || size > 0) {
2710                 *al = TLS1_AD_UNRECOGNIZED_NAME;
2711                 return 0;
2712             }
2713             tlsext_servername = 1;
2714         }
2715 # ifndef OPENSSL_NO_EC
2716         else if (type == TLSEXT_TYPE_ec_point_formats) {
2717             unsigned char *sdata = data;
2718             int ecpointformatlist_length;
2719 
2720             if (size == 0) {
2721                 *al = TLS1_AD_DECODE_ERROR;
2722                 return 0;
2723             }
2724 
2725             ecpointformatlist_length = *(sdata++);
2726             if (ecpointformatlist_length != size - 1) {
2727                 *al = TLS1_AD_DECODE_ERROR;
2728                 return 0;
2729             }
2730             if (!s->hit) {
2731                 s->session->tlsext_ecpointformatlist_length = 0;
2732                 if (s->session->tlsext_ecpointformatlist != NULL)
2733                     OPENSSL_free(s->session->tlsext_ecpointformatlist);
2734                 if ((s->session->tlsext_ecpointformatlist =
2735                      OPENSSL_malloc(ecpointformatlist_length)) == NULL) {
2736                     *al = TLS1_AD_INTERNAL_ERROR;
2737                     return 0;
2738                 }
2739                 s->session->tlsext_ecpointformatlist_length =
2740                     ecpointformatlist_length;
2741                 memcpy(s->session->tlsext_ecpointformatlist, sdata,
2742                        ecpointformatlist_length);
2743             }
2744 #  if 0
2745             fprintf(stderr,
2746                     "ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
2747             sdata = s->session->tlsext_ecpointformatlist;
2748             for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2749                 fprintf(stderr, "%i ", *(sdata++));
2750             fprintf(stderr, "\n");
2751 #  endif
2752         }
2753 # endif                         /* OPENSSL_NO_EC */
2754 
2755         else if (type == TLSEXT_TYPE_session_ticket) {
2756             if (s->tls_session_ticket_ext_cb &&
2757                 !s->tls_session_ticket_ext_cb(s, data, size,
2758                                               s->tls_session_ticket_ext_cb_arg))
2759             {
2760                 *al = TLS1_AD_INTERNAL_ERROR;
2761                 return 0;
2762             }
2763             if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
2764                 || (size > 0)) {
2765                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2766                 return 0;
2767             }
2768             s->tlsext_ticket_expected = 1;
2769         }
2770 # ifdef TLSEXT_TYPE_opaque_prf_input
2771         else if (type == TLSEXT_TYPE_opaque_prf_input) {
2772             unsigned char *sdata = data;
2773 
2774             if (size < 2) {
2775                 *al = SSL_AD_DECODE_ERROR;
2776                 return 0;
2777             }
2778             n2s(sdata, s->s3->server_opaque_prf_input_len);
2779             if (s->s3->server_opaque_prf_input_len != size - 2) {
2780                 *al = SSL_AD_DECODE_ERROR;
2781                 return 0;
2782             }
2783 
2784             if (s->s3->server_opaque_prf_input != NULL) {
2785                 /* shouldn't really happen */
2786                 OPENSSL_free(s->s3->server_opaque_prf_input);
2787             }
2788             if (s->s3->server_opaque_prf_input_len == 0) {
2789                 /* dummy byte just to get non-NULL */
2790                 s->s3->server_opaque_prf_input = OPENSSL_malloc(1);
2791             } else {
2792                 s->s3->server_opaque_prf_input =
2793                     BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
2794             }
2795 
2796             if (s->s3->server_opaque_prf_input == NULL) {
2797                 *al = TLS1_AD_INTERNAL_ERROR;
2798                 return 0;
2799             }
2800         }
2801 # endif
2802         else if (type == TLSEXT_TYPE_status_request) {
2803             /*
2804              * MUST be empty and only sent if we've requested a status
2805              * request message.
2806              */
2807             if ((s->tlsext_status_type == -1) || (size > 0)) {
2808                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2809                 return 0;
2810             }
2811             /* Set flag to expect CertificateStatus message */
2812             s->tlsext_status_expected = 1;
2813         }
2814 # ifndef OPENSSL_NO_NEXTPROTONEG
2815         else if (type == TLSEXT_TYPE_next_proto_neg &&
2816                  s->s3->tmp.finish_md_len == 0) {
2817             unsigned char *selected;
2818             unsigned char selected_len;
2819 
2820             /* We must have requested it. */
2821             if (s->ctx->next_proto_select_cb == NULL) {
2822                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2823                 return 0;
2824             }
2825             /* The data must be valid */
2826             if (!ssl_next_proto_validate(data, size)) {
2827                 *al = TLS1_AD_DECODE_ERROR;
2828                 return 0;
2829             }
2830             if (s->
2831                 ctx->next_proto_select_cb(s, &selected, &selected_len, data,
2832                                           size,
2833                                           s->ctx->next_proto_select_cb_arg) !=
2834                 SSL_TLSEXT_ERR_OK) {
2835                 *al = TLS1_AD_INTERNAL_ERROR;
2836                 return 0;
2837             }
2838             /*
2839              * Could be non-NULL if server has sent multiple NPN extensions in
2840              * a single Serverhello
2841              */
2842             OPENSSL_free(s->next_proto_negotiated);
2843             s->next_proto_negotiated = OPENSSL_malloc(selected_len);
2844             if (!s->next_proto_negotiated) {
2845                 *al = TLS1_AD_INTERNAL_ERROR;
2846                 return 0;
2847             }
2848             memcpy(s->next_proto_negotiated, selected, selected_len);
2849             s->next_proto_negotiated_len = selected_len;
2850             s->s3->next_proto_neg_seen = 1;
2851         }
2852 # endif
2853 
2854         else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation) {
2855             unsigned len;
2856 
2857             /* We must have requested it. */
2858             if (!s->cert->alpn_sent) {
2859                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2860                 return 0;
2861             }
2862             if (size < 4) {
2863                 *al = TLS1_AD_DECODE_ERROR;
2864                 return 0;
2865             }
2866             /*-
2867              * The extension data consists of:
2868              *   uint16 list_length
2869              *   uint8 proto_length;
2870              *   uint8 proto[proto_length];
2871              */
2872             len = data[0];
2873             len <<= 8;
2874             len |= data[1];
2875             if (len != (unsigned)size - 2) {
2876                 *al = TLS1_AD_DECODE_ERROR;
2877                 return 0;
2878             }
2879             len = data[2];
2880             if (len != (unsigned)size - 3) {
2881                 *al = TLS1_AD_DECODE_ERROR;
2882                 return 0;
2883             }
2884             if (s->s3->alpn_selected)
2885                 OPENSSL_free(s->s3->alpn_selected);
2886             s->s3->alpn_selected = OPENSSL_malloc(len);
2887             if (!s->s3->alpn_selected) {
2888                 *al = TLS1_AD_INTERNAL_ERROR;
2889                 return 0;
2890             }
2891             memcpy(s->s3->alpn_selected, data + 3, len);
2892             s->s3->alpn_selected_len = len;
2893         }
2894 
2895         else if (type == TLSEXT_TYPE_renegotiate) {
2896             if (!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
2897                 return 0;
2898             renegotiate_seen = 1;
2899         }
2900 # ifndef OPENSSL_NO_HEARTBEATS
2901         else if (type == TLSEXT_TYPE_heartbeat) {
2902             switch (data[0]) {
2903             case 0x01:         /* Server allows us to send HB requests */
2904                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2905                 break;
2906             case 0x02:         /* Server doesn't accept HB requests */
2907                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2908                 s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2909                 break;
2910             default:
2911                 *al = SSL_AD_ILLEGAL_PARAMETER;
2912                 return 0;
2913             }
2914         }
2915 # endif
2916 # ifndef OPENSSL_NO_SRTP
2917         else if (SSL_IS_DTLS(s) && type == TLSEXT_TYPE_use_srtp) {
2918             if (ssl_parse_serverhello_use_srtp_ext(s, data, size, al))
2919                 return 0;
2920         }
2921 # endif
2922         /*
2923          * If this extension type was not otherwise handled, but matches a
2924          * custom_cli_ext_record, then send it to the c callback
2925          */
2926         else if (custom_ext_parse(s, 0, type, data, size, al) <= 0)
2927             return 0;
2928 
2929         data += size;
2930     }
2931 
2932     if (data != d + n) {
2933         *al = SSL_AD_DECODE_ERROR;
2934         return 0;
2935     }
2936 
2937     if (!s->hit && tlsext_servername == 1) {
2938         if (s->tlsext_hostname) {
2939             if (s->session->tlsext_hostname == NULL) {
2940                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
2941                 if (!s->session->tlsext_hostname) {
2942                     *al = SSL_AD_UNRECOGNIZED_NAME;
2943                     return 0;
2944                 }
2945             } else {
2946                 *al = SSL_AD_DECODE_ERROR;
2947                 return 0;
2948             }
2949         }
2950     }
2951 
2952     *p = data;
2953 
2954  ri_check:
2955 
2956     /*
2957      * Determine if we need to see RI. Strictly speaking if we want to avoid
2958      * an attack we should *always* see RI even on initial server hello
2959      * because the client doesn't see any renegotiation during an attack.
2960      * However this would mean we could not connect to any server which
2961      * doesn't support RI so for the immediate future tolerate RI absence on
2962      * initial connect only.
2963      */
2964     if (!renegotiate_seen && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
2965         && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
2966         *al = SSL_AD_HANDSHAKE_FAILURE;
2967         SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT,
2968                SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2969         return 0;
2970     }
2971 
2972     return 1;
2973 }
2974 
2975 int ssl_prepare_clienthello_tlsext(SSL *s)
2976 {
2977 
2978 # ifdef TLSEXT_TYPE_opaque_prf_input
2979     {
2980         int r = 1;
2981 
2982         if (s->ctx->tlsext_opaque_prf_input_callback != 0) {
2983             r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0,
2984                                                          s->
2985                                                          ctx->tlsext_opaque_prf_input_callback_arg);
2986             if (!r)
2987                 return -1;
2988         }
2989 
2990         if (s->tlsext_opaque_prf_input != NULL) {
2991             if (s->s3->client_opaque_prf_input != NULL) {
2992                 /* shouldn't really happen */
2993                 OPENSSL_free(s->s3->client_opaque_prf_input);
2994             }
2995 
2996             if (s->tlsext_opaque_prf_input_len == 0) {
2997                 /* dummy byte just to get non-NULL */
2998                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1);
2999             } else {
3000                 s->s3->client_opaque_prf_input =
3001                     BUF_memdup(s->tlsext_opaque_prf_input,
3002                                s->tlsext_opaque_prf_input_len);
3003             }
3004             if (s->s3->client_opaque_prf_input == NULL) {
3005                 SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,
3006                        ERR_R_MALLOC_FAILURE);
3007                 return -1;
3008             }
3009             s->s3->client_opaque_prf_input_len =
3010                 s->tlsext_opaque_prf_input_len;
3011         }
3012 
3013         if (r == 2)
3014             /*
3015              * at callback's request, insist on receiving an appropriate
3016              * server opaque PRF input
3017              */
3018             s->s3->server_opaque_prf_input_len =
3019                 s->tlsext_opaque_prf_input_len;
3020     }
3021 # endif
3022 
3023     s->cert->alpn_sent = 0;
3024     return 1;
3025 }
3026 
3027 int ssl_prepare_serverhello_tlsext(SSL *s)
3028 {
3029     return 1;
3030 }
3031 
3032 static int ssl_check_clienthello_tlsext_early(SSL *s)
3033 {
3034     int ret = SSL_TLSEXT_ERR_NOACK;
3035     int al = SSL_AD_UNRECOGNIZED_NAME;
3036 
3037 # ifndef OPENSSL_NO_EC
3038     /*
3039      * The handling of the ECPointFormats extension is done elsewhere, namely
3040      * in ssl3_choose_cipher in s3_lib.c.
3041      */
3042     /*
3043      * The handling of the EllipticCurves extension is done elsewhere, namely
3044      * in ssl3_choose_cipher in s3_lib.c.
3045      */
3046 # endif
3047 
3048     if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
3049         ret =
3050             s->ctx->tlsext_servername_callback(s, &al,
3051                                                s->ctx->tlsext_servername_arg);
3052     else if (s->initial_ctx != NULL
3053              && s->initial_ctx->tlsext_servername_callback != 0)
3054         ret =
3055             s->initial_ctx->tlsext_servername_callback(s, &al,
3056                                                        s->
3057                                                        initial_ctx->tlsext_servername_arg);
3058 
3059 # ifdef TLSEXT_TYPE_opaque_prf_input
3060     {
3061         /*
3062          * This sort of belongs into ssl_prepare_serverhello_tlsext(), but we
3063          * might be sending an alert in response to the client hello, so this
3064          * has to happen here in ssl_check_clienthello_tlsext_early().
3065          */
3066 
3067         int r = 1;
3068 
3069         if (s->ctx->tlsext_opaque_prf_input_callback != 0) {
3070             r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0,
3071                                                          s->
3072                                                          ctx->tlsext_opaque_prf_input_callback_arg);
3073             if (!r) {
3074                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3075                 al = SSL_AD_INTERNAL_ERROR;
3076                 goto err;
3077             }
3078         }
3079 
3080         if (s->s3->server_opaque_prf_input != NULL) {
3081             /* shouldn't really happen */
3082             OPENSSL_free(s->s3->server_opaque_prf_input);
3083         }
3084         s->s3->server_opaque_prf_input = NULL;
3085 
3086         if (s->tlsext_opaque_prf_input != NULL) {
3087             if (s->s3->client_opaque_prf_input != NULL &&
3088                 s->s3->client_opaque_prf_input_len ==
3089                 s->tlsext_opaque_prf_input_len) {
3090                 /*
3091                  * can only use this extension if we have a server opaque PRF
3092                  * input of the same length as the client opaque PRF input!
3093                  */
3094 
3095                 if (s->tlsext_opaque_prf_input_len == 0) {
3096                     /* dummy byte just to get non-NULL */
3097                     s->s3->server_opaque_prf_input = OPENSSL_malloc(1);
3098                 } else {
3099                     s->s3->server_opaque_prf_input =
3100                         BUF_memdup(s->tlsext_opaque_prf_input,
3101                                    s->tlsext_opaque_prf_input_len);
3102                 }
3103                 if (s->s3->server_opaque_prf_input == NULL) {
3104                     ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3105                     al = SSL_AD_INTERNAL_ERROR;
3106                     goto err;
3107                 }
3108                 s->s3->server_opaque_prf_input_len =
3109                     s->tlsext_opaque_prf_input_len;
3110             }
3111         }
3112 
3113         if (r == 2 && s->s3->server_opaque_prf_input == NULL) {
3114             /*
3115              * The callback wants to enforce use of the extension, but we
3116              * can't do that with the client opaque PRF input; abort the
3117              * handshake.
3118              */
3119             ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3120             al = SSL_AD_HANDSHAKE_FAILURE;
3121         }
3122     }
3123 
3124  err:
3125 # endif
3126     switch (ret) {
3127     case SSL_TLSEXT_ERR_ALERT_FATAL:
3128         ssl3_send_alert(s, SSL3_AL_FATAL, al);
3129         return -1;
3130 
3131     case SSL_TLSEXT_ERR_ALERT_WARNING:
3132         ssl3_send_alert(s, SSL3_AL_WARNING, al);
3133         return 1;
3134 
3135     case SSL_TLSEXT_ERR_NOACK:
3136         s->servername_done = 0;
3137     default:
3138         return 1;
3139     }
3140 }
3141 
3142 int tls1_set_server_sigalgs(SSL *s)
3143 {
3144     int al;
3145     size_t i;
3146     /* Clear any shared sigtnature algorithms */
3147     if (s->cert->shared_sigalgs) {
3148         OPENSSL_free(s->cert->shared_sigalgs);
3149         s->cert->shared_sigalgs = NULL;
3150         s->cert->shared_sigalgslen = 0;
3151     }
3152     /* Clear certificate digests and validity flags */
3153     for (i = 0; i < SSL_PKEY_NUM; i++) {
3154         s->cert->pkeys[i].digest = NULL;
3155         s->cert->pkeys[i].valid_flags = 0;
3156     }
3157 
3158     /* If sigalgs received process it. */
3159     if (s->cert->peer_sigalgs) {
3160         if (!tls1_process_sigalgs(s)) {
3161             SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS, ERR_R_MALLOC_FAILURE);
3162             al = SSL_AD_INTERNAL_ERROR;
3163             goto err;
3164         }
3165         /* Fatal error is no shared signature algorithms */
3166         if (!s->cert->shared_sigalgs) {
3167             SSLerr(SSL_F_TLS1_SET_SERVER_SIGALGS,
3168                    SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
3169             al = SSL_AD_ILLEGAL_PARAMETER;
3170             goto err;
3171         }
3172     } else
3173         ssl_cert_set_default_md(s->cert);
3174     return 1;
3175  err:
3176     ssl3_send_alert(s, SSL3_AL_FATAL, al);
3177     return 0;
3178 }
3179 
3180 /*
3181  * Upon success, returns 1.
3182  * Upon failure, returns 0 and sets |al| to the appropriate fatal alert.
3183  */
3184 int ssl_check_clienthello_tlsext_late(SSL *s, int *al)
3185 {
3186 
3187     /*
3188      * If status request then ask callback what to do. Note: this must be
3189      * called after servername callbacks in case the certificate has changed,
3190      * and must be called after the cipher has been chosen because this may
3191      * influence which certificate is sent
3192      */
3193     if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb) {
3194         int ret;
3195         CERT_PKEY *certpkey;
3196         certpkey = ssl_get_server_send_pkey(s);
3197         /* If no certificate can't return certificate status */
3198         if (certpkey != NULL) {
3199             /*
3200              * Set current certificate to one we will use so SSL_get_certificate
3201              * et al can pick it up.
3202              */
3203             s->cert->key = certpkey;
3204             ret = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3205             switch (ret) {
3206                 /* We don't want to send a status request response */
3207             case SSL_TLSEXT_ERR_NOACK:
3208                 s->tlsext_status_expected = 0;
3209                 break;
3210                 /* status request response should be sent */
3211             case SSL_TLSEXT_ERR_OK:
3212                 if (s->tlsext_ocsp_resp)
3213                     s->tlsext_status_expected = 1;
3214                 break;
3215                 /* something bad happened */
3216             case SSL_TLSEXT_ERR_ALERT_FATAL:
3217             default:
3218                 *al = SSL_AD_INTERNAL_ERROR;
3219                 return 0;
3220             }
3221         }
3222     }
3223 
3224     if (!tls1_alpn_handle_client_hello_late(s, al)) {
3225         return 0;
3226     }
3227 
3228     return 1;
3229 }
3230 
3231 int ssl_check_serverhello_tlsext(SSL *s)
3232 {
3233     int ret = SSL_TLSEXT_ERR_NOACK;
3234     int al = SSL_AD_UNRECOGNIZED_NAME;
3235 
3236 # ifndef OPENSSL_NO_EC
3237     /*
3238      * If we are client and using an elliptic curve cryptography cipher
3239      * suite, then if server returns an EC point formats lists extension it
3240      * must contain uncompressed.
3241      */
3242     unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3243     unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3244     if ((s->tlsext_ecpointformatlist != NULL)
3245         && (s->tlsext_ecpointformatlist_length > 0)
3246         && (s->session->tlsext_ecpointformatlist != NULL)
3247         && (s->session->tlsext_ecpointformatlist_length > 0)
3248         && ((alg_k & (SSL_kEECDH | SSL_kECDHr | SSL_kECDHe))
3249             || (alg_a & SSL_aECDSA))) {
3250         /* we are using an ECC cipher */
3251         size_t i;
3252         unsigned char *list;
3253         int found_uncompressed = 0;
3254         list = s->session->tlsext_ecpointformatlist;
3255         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++) {
3256             if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed) {
3257                 found_uncompressed = 1;
3258                 break;
3259             }
3260         }
3261         if (!found_uncompressed) {
3262             SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,
3263                    SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
3264             return -1;
3265         }
3266     }
3267     ret = SSL_TLSEXT_ERR_OK;
3268 # endif                         /* OPENSSL_NO_EC */
3269 
3270     if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0)
3271         ret =
3272             s->ctx->tlsext_servername_callback(s, &al,
3273                                                s->ctx->tlsext_servername_arg);
3274     else if (s->initial_ctx != NULL
3275              && s->initial_ctx->tlsext_servername_callback != 0)
3276         ret =
3277             s->initial_ctx->tlsext_servername_callback(s, &al,
3278                                                        s->
3279                                                        initial_ctx->tlsext_servername_arg);
3280 
3281 # ifdef TLSEXT_TYPE_opaque_prf_input
3282     if (s->s3->server_opaque_prf_input_len > 0) {
3283         /*
3284          * This case may indicate that we, as a client, want to insist on
3285          * using opaque PRF inputs. So first verify that we really have a
3286          * value from the server too.
3287          */
3288 
3289         if (s->s3->server_opaque_prf_input == NULL) {
3290             ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3291             al = SSL_AD_HANDSHAKE_FAILURE;
3292         }
3293 
3294         /*
3295          * Anytime the server *has* sent an opaque PRF input, we need to
3296          * check that we have a client opaque PRF input of the same size.
3297          */
3298         if (s->s3->client_opaque_prf_input == NULL ||
3299             s->s3->client_opaque_prf_input_len !=
3300             s->s3->server_opaque_prf_input_len) {
3301             ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3302             al = SSL_AD_ILLEGAL_PARAMETER;
3303         }
3304     }
3305 # endif
3306 
3307     OPENSSL_free(s->tlsext_ocsp_resp);
3308     s->tlsext_ocsp_resp = NULL;
3309     s->tlsext_ocsp_resplen = -1;
3310     /*
3311      * If we've requested certificate status and we wont get one tell the
3312      * callback
3313      */
3314     if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
3315         && !(s->hit) && s->ctx && s->ctx->tlsext_status_cb) {
3316         int r;
3317         /*
3318          * Call callback with resp == NULL and resplen == -1 so callback
3319          * knows there is no response
3320          */
3321         r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3322         if (r == 0) {
3323             al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
3324             ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3325         }
3326         if (r < 0) {
3327             al = SSL_AD_INTERNAL_ERROR;
3328             ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3329         }
3330     }
3331 
3332     switch (ret) {
3333     case SSL_TLSEXT_ERR_ALERT_FATAL:
3334         ssl3_send_alert(s, SSL3_AL_FATAL, al);
3335         return -1;
3336 
3337     case SSL_TLSEXT_ERR_ALERT_WARNING:
3338         ssl3_send_alert(s, SSL3_AL_WARNING, al);
3339         return 1;
3340 
3341     case SSL_TLSEXT_ERR_NOACK:
3342         s->servername_done = 0;
3343     default:
3344         return 1;
3345     }
3346 }
3347 
3348 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d,
3349                                  int n)
3350 {
3351     int al = -1;
3352     if (s->version < SSL3_VERSION)
3353         return 1;
3354     if (ssl_scan_serverhello_tlsext(s, p, d, n, &al) <= 0) {
3355         ssl3_send_alert(s, SSL3_AL_FATAL, al);
3356         return 0;
3357     }
3358 
3359     if (ssl_check_serverhello_tlsext(s) <= 0) {
3360         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT, SSL_R_SERVERHELLO_TLSEXT);
3361         return 0;
3362     }
3363     return 1;
3364 }
3365 
3366 /*-
3367  * Since the server cache lookup is done early on in the processing of the
3368  * ClientHello, and other operations depend on the result, we need to handle
3369  * any TLS session ticket extension at the same time.
3370  *
3371  *   session_id: points at the session ID in the ClientHello. This code will
3372  *       read past the end of this in order to parse out the session ticket
3373  *       extension, if any.
3374  *   len: the length of the session ID.
3375  *   limit: a pointer to the first byte after the ClientHello.
3376  *   ret: (output) on return, if a ticket was decrypted, then this is set to
3377  *       point to the resulting session.
3378  *
3379  * If s->tls_session_secret_cb is set then we are expecting a pre-shared key
3380  * ciphersuite, in which case we have no use for session tickets and one will
3381  * never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
3382  *
3383  * Returns:
3384  *   -1: fatal error, either from parsing or decrypting the ticket.
3385  *    0: no ticket was found (or was ignored, based on settings).
3386  *    1: a zero length extension was found, indicating that the client supports
3387  *       session tickets but doesn't currently have one to offer.
3388  *    2: either s->tls_session_secret_cb was set, or a ticket was offered but
3389  *       couldn't be decrypted because of a non-fatal error.
3390  *    3: a ticket was successfully decrypted and *ret was set.
3391  *
3392  * Side effects:
3393  *   Sets s->tlsext_ticket_expected to 1 if the server will have to issue
3394  *   a new session ticket to the client because the client indicated support
3395  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
3396  *   a session ticket or we couldn't use the one it gave us, or if
3397  *   s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
3398  *   Otherwise, s->tlsext_ticket_expected is set to 0.
3399  */
3400 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
3401                         const unsigned char *limit, SSL_SESSION **ret)
3402 {
3403     /* Point after session ID in client hello */
3404     const unsigned char *p = session_id + len;
3405     unsigned short i;
3406 
3407     *ret = NULL;
3408     s->tlsext_ticket_expected = 0;
3409 
3410     /*
3411      * If tickets disabled behave as if no ticket present to permit stateful
3412      * resumption.
3413      */
3414     if (SSL_get_options(s) & SSL_OP_NO_TICKET)
3415         return 0;
3416     if ((s->version <= SSL3_VERSION) || !limit)
3417         return 0;
3418     if (p >= limit)
3419         return -1;
3420     /* Skip past DTLS cookie */
3421     if (SSL_IS_DTLS(s)) {
3422         i = *(p++);
3423 
3424         if (limit - p <= i)
3425             return -1;
3426 
3427         p += i;
3428     }
3429     /* Skip past cipher list */
3430     n2s(p, i);
3431     if (limit - p <= i)
3432         return -1;
3433     p += i;
3434 
3435     /* Skip past compression algorithm list */
3436     i = *(p++);
3437     if (limit - p < i)
3438         return -1;
3439     p += i;
3440 
3441     /* Now at start of extensions */
3442     if (limit - p <= 2)
3443         return 0;
3444     n2s(p, i);
3445     while (limit - p >= 4) {
3446         unsigned short type, size;
3447         n2s(p, type);
3448         n2s(p, size);
3449         if (limit - p < size)
3450             return 0;
3451         if (type == TLSEXT_TYPE_session_ticket) {
3452             int r;
3453             if (size == 0) {
3454                 /*
3455                  * The client will accept a ticket but doesn't currently have
3456                  * one.
3457                  */
3458                 s->tlsext_ticket_expected = 1;
3459                 return 1;
3460             }
3461             if (s->tls_session_secret_cb) {
3462                 /*
3463                  * Indicate that the ticket couldn't be decrypted rather than
3464                  * generating the session from ticket now, trigger
3465                  * abbreviated handshake based on external mechanism to
3466                  * calculate the master secret later.
3467                  */
3468                 return 2;
3469             }
3470             r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
3471             switch (r) {
3472             case 2:            /* ticket couldn't be decrypted */
3473                 s->tlsext_ticket_expected = 1;
3474                 return 2;
3475             case 3:            /* ticket was decrypted */
3476                 return r;
3477             case 4:            /* ticket decrypted but need to renew */
3478                 s->tlsext_ticket_expected = 1;
3479                 return 3;
3480             default:           /* fatal error */
3481                 return -1;
3482             }
3483         }
3484         p += size;
3485     }
3486     return 0;
3487 }
3488 
3489 /*-
3490  * tls_decrypt_ticket attempts to decrypt a session ticket.
3491  *
3492  *   etick: points to the body of the session ticket extension.
3493  *   eticklen: the length of the session tickets extenion.
3494  *   sess_id: points at the session ID.
3495  *   sesslen: the length of the session ID.
3496  *   psess: (output) on return, if a ticket was decrypted, then this is set to
3497  *       point to the resulting session.
3498  *
3499  * Returns:
3500  *   -1: fatal error, either from parsing or decrypting the ticket.
3501  *    2: the ticket couldn't be decrypted.
3502  *    3: a ticket was successfully decrypted and *psess was set.
3503  *    4: same as 3, but the ticket needs to be renewed.
3504  */
3505 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick,
3506                               int eticklen, const unsigned char *sess_id,
3507                               int sesslen, SSL_SESSION **psess)
3508 {
3509     SSL_SESSION *sess;
3510     unsigned char *sdec;
3511     const unsigned char *p;
3512     int slen, mlen, renew_ticket = 0;
3513     unsigned char tick_hmac[EVP_MAX_MD_SIZE];
3514     HMAC_CTX hctx;
3515     EVP_CIPHER_CTX ctx;
3516     SSL_CTX *tctx = s->initial_ctx;
3517 
3518     /* Need at least keyname + iv */
3519     if (eticklen < 16 + EVP_MAX_IV_LENGTH)
3520         return 2;
3521 
3522     /* Initialize session ticket encryption and HMAC contexts */
3523     HMAC_CTX_init(&hctx);
3524     EVP_CIPHER_CTX_init(&ctx);
3525     if (tctx->tlsext_ticket_key_cb) {
3526         unsigned char *nctick = (unsigned char *)etick;
3527         int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
3528                                             &ctx, &hctx, 0);
3529         if (rv < 0)
3530             goto err;
3531         if (rv == 0) {
3532             HMAC_CTX_cleanup(&hctx);
3533             EVP_CIPHER_CTX_cleanup(&ctx);
3534             return 2;
3535         }
3536         if (rv == 2)
3537             renew_ticket = 1;
3538     } else {
3539         /* Check key name matches */
3540         if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
3541             return 2;
3542         if (HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
3543                          tlsext_tick_md(), NULL) <= 0
3544                 || EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
3545                                       tctx->tlsext_tick_aes_key,
3546                                       etick + 16) <= 0) {
3547             goto err;
3548        }
3549     }
3550     /*
3551      * Attempt to process session ticket, first conduct sanity and integrity
3552      * checks on ticket.
3553      */
3554     mlen = HMAC_size(&hctx);
3555     if (mlen < 0) {
3556         goto err;
3557     }
3558     /* Sanity check ticket length: must exceed keyname + IV + HMAC */
3559     if (eticklen <= 16 + EVP_CIPHER_CTX_iv_length(&ctx) + mlen) {
3560         HMAC_CTX_cleanup(&hctx);
3561         EVP_CIPHER_CTX_cleanup(&ctx);
3562         return 2;
3563     }
3564 
3565     eticklen -= mlen;
3566     /* Check HMAC of encrypted ticket */
3567     if (HMAC_Update(&hctx, etick, eticklen) <= 0
3568             || HMAC_Final(&hctx, tick_hmac, NULL) <= 0) {
3569         goto err;
3570     }
3571     HMAC_CTX_cleanup(&hctx);
3572     if (CRYPTO_memcmp(tick_hmac, etick + eticklen, mlen)) {
3573         EVP_CIPHER_CTX_cleanup(&ctx);
3574         return 2;
3575     }
3576     /* Attempt to decrypt session data */
3577     /* Move p after IV to start of encrypted ticket, update length */
3578     p = etick + 16 + EVP_CIPHER_CTX_iv_length(&ctx);
3579     eticklen -= 16 + EVP_CIPHER_CTX_iv_length(&ctx);
3580     sdec = OPENSSL_malloc(eticklen);
3581     if (sdec == NULL
3582             || EVP_DecryptUpdate(&ctx, sdec, &slen, p, eticklen) <= 0) {
3583         EVP_CIPHER_CTX_cleanup(&ctx);
3584         OPENSSL_free(sdec);
3585         return -1;
3586     }
3587     if (EVP_DecryptFinal(&ctx, sdec + slen, &mlen) <= 0) {
3588         EVP_CIPHER_CTX_cleanup(&ctx);
3589         OPENSSL_free(sdec);
3590         return 2;
3591     }
3592     slen += mlen;
3593     EVP_CIPHER_CTX_cleanup(&ctx);
3594     p = sdec;
3595 
3596     sess = d2i_SSL_SESSION(NULL, &p, slen);
3597     slen -= p - sdec;
3598     OPENSSL_free(sdec);
3599     if (sess) {
3600         /* Some additional consistency checks */
3601         if (slen != 0 || sess->session_id_length != 0) {
3602             SSL_SESSION_free(sess);
3603             return 2;
3604         }
3605         /*
3606          * The session ID, if non-empty, is used by some clients to detect
3607          * that the ticket has been accepted. So we copy it to the session
3608          * structure. If it is empty set length to zero as required by
3609          * standard.
3610          */
3611         if (sesslen)
3612             memcpy(sess->session_id, sess_id, sesslen);
3613         sess->session_id_length = sesslen;
3614         *psess = sess;
3615         if (renew_ticket)
3616             return 4;
3617         else
3618             return 3;
3619     }
3620     ERR_clear_error();
3621     /*
3622      * For session parse failure, indicate that we need to send a new ticket.
3623      */
3624     return 2;
3625 err:
3626     EVP_CIPHER_CTX_cleanup(&ctx);
3627     HMAC_CTX_cleanup(&hctx);
3628     return -1;
3629 }
3630 
3631 /* Tables to translate from NIDs to TLS v1.2 ids */
3632 
3633 typedef struct {
3634     int nid;
3635     int id;
3636 } tls12_lookup;
3637 
3638 static tls12_lookup tls12_md[] = {
3639     {NID_md5, TLSEXT_hash_md5},
3640     {NID_sha1, TLSEXT_hash_sha1},
3641     {NID_sha224, TLSEXT_hash_sha224},
3642     {NID_sha256, TLSEXT_hash_sha256},
3643     {NID_sha384, TLSEXT_hash_sha384},
3644     {NID_sha512, TLSEXT_hash_sha512}
3645 };
3646 
3647 static tls12_lookup tls12_sig[] = {
3648     {EVP_PKEY_RSA, TLSEXT_signature_rsa},
3649     {EVP_PKEY_DSA, TLSEXT_signature_dsa},
3650     {EVP_PKEY_EC, TLSEXT_signature_ecdsa}
3651 };
3652 
3653 static int tls12_find_id(int nid, tls12_lookup *table, size_t tlen)
3654 {
3655     size_t i;
3656     for (i = 0; i < tlen; i++) {
3657         if (table[i].nid == nid)
3658             return table[i].id;
3659     }
3660     return -1;
3661 }
3662 
3663 static int tls12_find_nid(int id, tls12_lookup *table, size_t tlen)
3664 {
3665     size_t i;
3666     for (i = 0; i < tlen; i++) {
3667         if ((table[i].id) == id)
3668             return table[i].nid;
3669     }
3670     return NID_undef;
3671 }
3672 
3673 int tls12_get_sigandhash(unsigned char *p, const EVP_PKEY *pk,
3674                          const EVP_MD *md)
3675 {
3676     int sig_id, md_id;
3677     if (!md)
3678         return 0;
3679     md_id = tls12_find_id(EVP_MD_type(md), tls12_md,
3680                           sizeof(tls12_md) / sizeof(tls12_lookup));
3681     if (md_id == -1)
3682         return 0;
3683     sig_id = tls12_get_sigid(pk);
3684     if (sig_id == -1)
3685         return 0;
3686     p[0] = (unsigned char)md_id;
3687     p[1] = (unsigned char)sig_id;
3688     return 1;
3689 }
3690 
3691 int tls12_get_sigid(const EVP_PKEY *pk)
3692 {
3693     return tls12_find_id(pk->type, tls12_sig,
3694                          sizeof(tls12_sig) / sizeof(tls12_lookup));
3695 }
3696 
3697 const EVP_MD *tls12_get_hash(unsigned char hash_alg)
3698 {
3699     switch (hash_alg) {
3700 # ifndef OPENSSL_NO_MD5
3701     case TLSEXT_hash_md5:
3702 #  ifdef OPENSSL_FIPS
3703         if (FIPS_mode())
3704             return NULL;
3705 #  endif
3706         return EVP_md5();
3707 # endif
3708 # ifndef OPENSSL_NO_SHA
3709     case TLSEXT_hash_sha1:
3710         return EVP_sha1();
3711 # endif
3712 # ifndef OPENSSL_NO_SHA256
3713     case TLSEXT_hash_sha224:
3714         return EVP_sha224();
3715 
3716     case TLSEXT_hash_sha256:
3717         return EVP_sha256();
3718 # endif
3719 # ifndef OPENSSL_NO_SHA512
3720     case TLSEXT_hash_sha384:
3721         return EVP_sha384();
3722 
3723     case TLSEXT_hash_sha512:
3724         return EVP_sha512();
3725 # endif
3726     default:
3727         return NULL;
3728 
3729     }
3730 }
3731 
3732 static int tls12_get_pkey_idx(unsigned char sig_alg)
3733 {
3734     switch (sig_alg) {
3735 # ifndef OPENSSL_NO_RSA
3736     case TLSEXT_signature_rsa:
3737         return SSL_PKEY_RSA_SIGN;
3738 # endif
3739 # ifndef OPENSSL_NO_DSA
3740     case TLSEXT_signature_dsa:
3741         return SSL_PKEY_DSA_SIGN;
3742 # endif
3743 # ifndef OPENSSL_NO_ECDSA
3744     case TLSEXT_signature_ecdsa:
3745         return SSL_PKEY_ECC;
3746 # endif
3747     }
3748     return -1;
3749 }
3750 
3751 /* Convert TLS 1.2 signature algorithm extension values into NIDs */
3752 static void tls1_lookup_sigalg(int *phash_nid, int *psign_nid,
3753                                int *psignhash_nid, const unsigned char *data)
3754 {
3755     int sign_nid = NID_undef, hash_nid = NID_undef;
3756     if (!phash_nid && !psign_nid && !psignhash_nid)
3757         return;
3758     if (phash_nid || psignhash_nid) {
3759         hash_nid = tls12_find_nid(data[0], tls12_md,
3760                                   sizeof(tls12_md) / sizeof(tls12_lookup));
3761         if (phash_nid)
3762             *phash_nid = hash_nid;
3763     }
3764     if (psign_nid || psignhash_nid) {
3765         sign_nid = tls12_find_nid(data[1], tls12_sig,
3766                                   sizeof(tls12_sig) / sizeof(tls12_lookup));
3767         if (psign_nid)
3768             *psign_nid = sign_nid;
3769     }
3770     if (psignhash_nid) {
3771         if (sign_nid == NID_undef || hash_nid == NID_undef
3772                 || OBJ_find_sigid_by_algs(psignhash_nid, hash_nid,
3773                                           sign_nid) <= 0)
3774             *psignhash_nid = NID_undef;
3775     }
3776 }
3777 
3778 /* Given preference and allowed sigalgs set shared sigalgs */
3779 static int tls12_do_shared_sigalgs(TLS_SIGALGS *shsig,
3780                                    const unsigned char *pref, size_t preflen,
3781                                    const unsigned char *allow,
3782                                    size_t allowlen)
3783 {
3784     const unsigned char *ptmp, *atmp;
3785     size_t i, j, nmatch = 0;
3786     for (i = 0, ptmp = pref; i < preflen; i += 2, ptmp += 2) {
3787         /* Skip disabled hashes or signature algorithms */
3788         if (tls12_get_hash(ptmp[0]) == NULL)
3789             continue;
3790         if (tls12_get_pkey_idx(ptmp[1]) == -1)
3791             continue;
3792         for (j = 0, atmp = allow; j < allowlen; j += 2, atmp += 2) {
3793             if (ptmp[0] == atmp[0] && ptmp[1] == atmp[1]) {
3794                 nmatch++;
3795                 if (shsig) {
3796                     shsig->rhash = ptmp[0];
3797                     shsig->rsign = ptmp[1];
3798                     tls1_lookup_sigalg(&shsig->hash_nid,
3799                                        &shsig->sign_nid,
3800                                        &shsig->signandhash_nid, ptmp);
3801                     shsig++;
3802                 }
3803                 break;
3804             }
3805         }
3806     }
3807     return nmatch;
3808 }
3809 
3810 /* Set shared signature algorithms for SSL structures */
3811 static int tls1_set_shared_sigalgs(SSL *s)
3812 {
3813     const unsigned char *pref, *allow, *conf;
3814     size_t preflen, allowlen, conflen;
3815     size_t nmatch;
3816     TLS_SIGALGS *salgs = NULL;
3817     CERT *c = s->cert;
3818     unsigned int is_suiteb = tls1_suiteb(s);
3819     if (c->shared_sigalgs) {
3820         OPENSSL_free(c->shared_sigalgs);
3821         c->shared_sigalgs = NULL;
3822         c->shared_sigalgslen = 0;
3823     }
3824     /* If client use client signature algorithms if not NULL */
3825     if (!s->server && c->client_sigalgs && !is_suiteb) {
3826         conf = c->client_sigalgs;
3827         conflen = c->client_sigalgslen;
3828     } else if (c->conf_sigalgs && !is_suiteb) {
3829         conf = c->conf_sigalgs;
3830         conflen = c->conf_sigalgslen;
3831     } else
3832         conflen = tls12_get_psigalgs(s, 0, &conf);
3833     if (s->options & SSL_OP_CIPHER_SERVER_PREFERENCE || is_suiteb) {
3834         pref = conf;
3835         preflen = conflen;
3836         allow = c->peer_sigalgs;
3837         allowlen = c->peer_sigalgslen;
3838     } else {
3839         allow = conf;
3840         allowlen = conflen;
3841         pref = c->peer_sigalgs;
3842         preflen = c->peer_sigalgslen;
3843     }
3844     nmatch = tls12_do_shared_sigalgs(NULL, pref, preflen, allow, allowlen);
3845     if (nmatch) {
3846         salgs = OPENSSL_malloc(nmatch * sizeof(TLS_SIGALGS));
3847         if (!salgs)
3848             return 0;
3849         nmatch = tls12_do_shared_sigalgs(salgs, pref, preflen, allow, allowlen);
3850     } else {
3851         salgs = NULL;
3852     }
3853     c->shared_sigalgs = salgs;
3854     c->shared_sigalgslen = nmatch;
3855     return 1;
3856 }
3857 
3858 /* Set preferred digest for each key type */
3859 
3860 int tls1_save_sigalgs(SSL *s, const unsigned char *data, int dsize)
3861 {
3862     CERT *c = s->cert;
3863     /* Extension ignored for inappropriate versions */
3864     if (!SSL_USE_SIGALGS(s))
3865         return 1;
3866     /* Should never happen */
3867     if (!c)
3868         return 0;
3869 
3870     if (c->peer_sigalgs)
3871         OPENSSL_free(c->peer_sigalgs);
3872     c->peer_sigalgs = OPENSSL_malloc(dsize);
3873     if (!c->peer_sigalgs)
3874         return 0;
3875     c->peer_sigalgslen = dsize;
3876     memcpy(c->peer_sigalgs, data, dsize);
3877     return 1;
3878 }
3879 
3880 int tls1_process_sigalgs(SSL *s)
3881 {
3882     int idx;
3883     size_t i;
3884     const EVP_MD *md;
3885     CERT *c = s->cert;
3886     TLS_SIGALGS *sigptr;
3887     if (!tls1_set_shared_sigalgs(s))
3888         return 0;
3889 
3890 # ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
3891     if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL) {
3892         /*
3893          * Use first set signature preference to force message digest,
3894          * ignoring any peer preferences.
3895          */
3896         const unsigned char *sigs = NULL;
3897         if (s->server)
3898             sigs = c->conf_sigalgs;
3899         else
3900             sigs = c->client_sigalgs;
3901         if (sigs) {
3902             idx = tls12_get_pkey_idx(sigs[1]);
3903             md = tls12_get_hash(sigs[0]);
3904             c->pkeys[idx].digest = md;
3905             c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3906             if (idx == SSL_PKEY_RSA_SIGN) {
3907                 c->pkeys[SSL_PKEY_RSA_ENC].valid_flags =
3908                     CERT_PKEY_EXPLICIT_SIGN;
3909                 c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
3910             }
3911         }
3912     }
3913 # endif
3914 
3915     for (i = 0, sigptr = c->shared_sigalgs;
3916          i < c->shared_sigalgslen; i++, sigptr++) {
3917         idx = tls12_get_pkey_idx(sigptr->rsign);
3918         if (idx > 0 && c->pkeys[idx].digest == NULL) {
3919             md = tls12_get_hash(sigptr->rhash);
3920             c->pkeys[idx].digest = md;
3921             c->pkeys[idx].valid_flags = CERT_PKEY_EXPLICIT_SIGN;
3922             if (idx == SSL_PKEY_RSA_SIGN) {
3923                 c->pkeys[SSL_PKEY_RSA_ENC].valid_flags =
3924                     CERT_PKEY_EXPLICIT_SIGN;
3925                 c->pkeys[SSL_PKEY_RSA_ENC].digest = md;
3926             }
3927         }
3928 
3929     }
3930     /*
3931      * In strict mode leave unset digests as NULL to indicate we can't use
3932      * the certificate for signing.
3933      */
3934     if (!(s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)) {
3935         /*
3936          * Set any remaining keys to default values. NOTE: if alg is not
3937          * supported it stays as NULL.
3938          */
3939 # ifndef OPENSSL_NO_DSA
3940         if (!c->pkeys[SSL_PKEY_DSA_SIGN].digest)
3941             c->pkeys[SSL_PKEY_DSA_SIGN].digest = EVP_sha1();
3942 # endif
3943 # ifndef OPENSSL_NO_RSA
3944         if (!c->pkeys[SSL_PKEY_RSA_SIGN].digest) {
3945             c->pkeys[SSL_PKEY_RSA_SIGN].digest = EVP_sha1();
3946             c->pkeys[SSL_PKEY_RSA_ENC].digest = EVP_sha1();
3947         }
3948 # endif
3949 # ifndef OPENSSL_NO_ECDSA
3950         if (!c->pkeys[SSL_PKEY_ECC].digest)
3951             c->pkeys[SSL_PKEY_ECC].digest = EVP_sha1();
3952 # endif
3953     }
3954     return 1;
3955 }
3956 
3957 int SSL_get_sigalgs(SSL *s, int idx,
3958                     int *psign, int *phash, int *psignhash,
3959                     unsigned char *rsig, unsigned char *rhash)
3960 {
3961     const unsigned char *psig = s->cert->peer_sigalgs;
3962     if (psig == NULL)
3963         return 0;
3964     if (idx >= 0) {
3965         idx <<= 1;
3966         if (idx >= (int)s->cert->peer_sigalgslen)
3967             return 0;
3968         psig += idx;
3969         if (rhash)
3970             *rhash = psig[0];
3971         if (rsig)
3972             *rsig = psig[1];
3973         tls1_lookup_sigalg(phash, psign, psignhash, psig);
3974     }
3975     return s->cert->peer_sigalgslen / 2;
3976 }
3977 
3978 int SSL_get_shared_sigalgs(SSL *s, int idx,
3979                            int *psign, int *phash, int *psignhash,
3980                            unsigned char *rsig, unsigned char *rhash)
3981 {
3982     TLS_SIGALGS *shsigalgs = s->cert->shared_sigalgs;
3983     if (!shsigalgs || idx >= (int)s->cert->shared_sigalgslen)
3984         return 0;
3985     shsigalgs += idx;
3986     if (phash)
3987         *phash = shsigalgs->hash_nid;
3988     if (psign)
3989         *psign = shsigalgs->sign_nid;
3990     if (psignhash)
3991         *psignhash = shsigalgs->signandhash_nid;
3992     if (rsig)
3993         *rsig = shsigalgs->rsign;
3994     if (rhash)
3995         *rhash = shsigalgs->rhash;
3996     return s->cert->shared_sigalgslen;
3997 }
3998 
3999 # ifndef OPENSSL_NO_HEARTBEATS
4000 int tls1_process_heartbeat(SSL *s)
4001 {
4002     unsigned char *p = &s->s3->rrec.data[0], *pl;
4003     unsigned short hbtype;
4004     unsigned int payload;
4005     unsigned int padding = 16;  /* Use minimum padding */
4006 
4007     if (s->msg_callback)
4008         s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
4009                         &s->s3->rrec.data[0], s->s3->rrec.length,
4010                         s, s->msg_callback_arg);
4011 
4012     /* Read type and payload length first */
4013     if (1 + 2 + 16 > s->s3->rrec.length)
4014         return 0;               /* silently discard */
4015     hbtype = *p++;
4016     n2s(p, payload);
4017     if (1 + 2 + payload + 16 > s->s3->rrec.length)
4018         return 0;               /* silently discard per RFC 6520 sec. 4 */
4019     pl = p;
4020 
4021     if (hbtype == TLS1_HB_REQUEST) {
4022         unsigned char *buffer, *bp;
4023         int r;
4024 
4025         /*
4026          * Allocate memory for the response, size is 1 bytes message type,
4027          * plus 2 bytes payload length, plus payload, plus padding
4028          */
4029         buffer = OPENSSL_malloc(1 + 2 + payload + padding);
4030         if (buffer == NULL)
4031             return -1;
4032         bp = buffer;
4033 
4034         /* Enter response type, length and copy payload */
4035         *bp++ = TLS1_HB_RESPONSE;
4036         s2n(payload, bp);
4037         memcpy(bp, pl, payload);
4038         bp += payload;
4039         /* Random padding */
4040         if (RAND_bytes(bp, padding) <= 0) {
4041             OPENSSL_free(buffer);
4042             return -1;
4043         }
4044 
4045         r = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buffer,
4046                              3 + payload + padding);
4047 
4048         if (r >= 0 && s->msg_callback)
4049             s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
4050                             buffer, 3 + payload + padding,
4051                             s, s->msg_callback_arg);
4052 
4053         OPENSSL_free(buffer);
4054 
4055         if (r < 0)
4056             return r;
4057     } else if (hbtype == TLS1_HB_RESPONSE) {
4058         unsigned int seq;
4059 
4060         /*
4061          * We only send sequence numbers (2 bytes unsigned int), and 16
4062          * random bytes, so we just try to read the sequence number
4063          */
4064         n2s(pl, seq);
4065 
4066         if (payload == 18 && seq == s->tlsext_hb_seq) {
4067             s->tlsext_hb_seq++;
4068             s->tlsext_hb_pending = 0;
4069         }
4070     }
4071 
4072     return 0;
4073 }
4074 
4075 int tls1_heartbeat(SSL *s)
4076 {
4077     unsigned char *buf, *p;
4078     int ret = -1;
4079     unsigned int payload = 18;  /* Sequence number + random bytes */
4080     unsigned int padding = 16;  /* Use minimum padding */
4081 
4082     /* Only send if peer supports and accepts HB requests... */
4083     if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
4084         s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
4085         SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
4086         return -1;
4087     }
4088 
4089     /* ...and there is none in flight yet... */
4090     if (s->tlsext_hb_pending) {
4091         SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
4092         return -1;
4093     }
4094 
4095     /* ...and no handshake in progress. */
4096     if (SSL_in_init(s) || s->in_handshake) {
4097         SSLerr(SSL_F_TLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
4098         return -1;
4099     }
4100 
4101     /*
4102      * Check if padding is too long, payload and padding must not exceed 2^14
4103      * - 3 = 16381 bytes in total.
4104      */
4105     OPENSSL_assert(payload + padding <= 16381);
4106 
4107     /*-
4108      * Create HeartBeat message, we just use a sequence number
4109      * as payload to distuingish different messages and add
4110      * some random stuff.
4111      *  - Message Type, 1 byte
4112      *  - Payload Length, 2 bytes (unsigned int)
4113      *  - Payload, the sequence number (2 bytes uint)
4114      *  - Payload, random bytes (16 bytes uint)
4115      *  - Padding
4116      */
4117     buf = OPENSSL_malloc(1 + 2 + payload + padding);
4118     if (buf == NULL)
4119         return -1;
4120     p = buf;
4121     /* Message Type */
4122     *p++ = TLS1_HB_REQUEST;
4123     /* Payload length (18 bytes here) */
4124     s2n(payload, p);
4125     /* Sequence number */
4126     s2n(s->tlsext_hb_seq, p);
4127     /* 16 random bytes */
4128     if (RAND_bytes(p, 16) <= 0) {
4129         SSLerr(SSL_F_TLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
4130         goto err;
4131     }
4132     p += 16;
4133     /* Random padding */
4134     if (RAND_bytes(p, padding) <= 0) {
4135         SSLerr(SSL_F_TLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
4136         goto err;
4137     }
4138 
4139     ret = ssl3_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
4140     if (ret >= 0) {
4141         if (s->msg_callback)
4142             s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
4143                             buf, 3 + payload + padding,
4144                             s, s->msg_callback_arg);
4145 
4146         s->tlsext_hb_pending = 1;
4147     }
4148 
4149 err:
4150     OPENSSL_free(buf);
4151 
4152     return ret;
4153 }
4154 # endif
4155 
4156 # define MAX_SIGALGLEN   (TLSEXT_hash_num * TLSEXT_signature_num * 2)
4157 
4158 typedef struct {
4159     size_t sigalgcnt;
4160     int sigalgs[MAX_SIGALGLEN];
4161 } sig_cb_st;
4162 
4163 static int sig_cb(const char *elem, int len, void *arg)
4164 {
4165     sig_cb_st *sarg = arg;
4166     size_t i;
4167     char etmp[20], *p;
4168     int sig_alg, hash_alg;
4169     if (elem == NULL)
4170         return 0;
4171     if (sarg->sigalgcnt == MAX_SIGALGLEN)
4172         return 0;
4173     if (len > (int)(sizeof(etmp) - 1))
4174         return 0;
4175     memcpy(etmp, elem, len);
4176     etmp[len] = 0;
4177     p = strchr(etmp, '+');
4178     if (!p)
4179         return 0;
4180     *p = 0;
4181     p++;
4182     if (!*p)
4183         return 0;
4184 
4185     if (!strcmp(etmp, "RSA"))
4186         sig_alg = EVP_PKEY_RSA;
4187     else if (!strcmp(etmp, "DSA"))
4188         sig_alg = EVP_PKEY_DSA;
4189     else if (!strcmp(etmp, "ECDSA"))
4190         sig_alg = EVP_PKEY_EC;
4191     else
4192         return 0;
4193 
4194     hash_alg = OBJ_sn2nid(p);
4195     if (hash_alg == NID_undef)
4196         hash_alg = OBJ_ln2nid(p);
4197     if (hash_alg == NID_undef)
4198         return 0;
4199 
4200     for (i = 0; i < sarg->sigalgcnt; i += 2) {
4201         if (sarg->sigalgs[i] == sig_alg && sarg->sigalgs[i + 1] == hash_alg)
4202             return 0;
4203     }
4204     sarg->sigalgs[sarg->sigalgcnt++] = hash_alg;
4205     sarg->sigalgs[sarg->sigalgcnt++] = sig_alg;
4206     return 1;
4207 }
4208 
4209 /*
4210  * Set suppored signature algorithms based on a colon separated list of the
4211  * form sig+hash e.g. RSA+SHA512:DSA+SHA512
4212  */
4213 int tls1_set_sigalgs_list(CERT *c, const char *str, int client)
4214 {
4215     sig_cb_st sig;
4216     sig.sigalgcnt = 0;
4217     if (!CONF_parse_list(str, ':', 1, sig_cb, &sig))
4218         return 0;
4219     if (c == NULL)
4220         return 1;
4221     return tls1_set_sigalgs(c, sig.sigalgs, sig.sigalgcnt, client);
4222 }
4223 
4224 int tls1_set_sigalgs(CERT *c, const int *psig_nids, size_t salglen,
4225                      int client)
4226 {
4227     unsigned char *sigalgs, *sptr;
4228     int rhash, rsign;
4229     size_t i;
4230     if (salglen & 1)
4231         return 0;
4232     sigalgs = OPENSSL_malloc(salglen);
4233     if (sigalgs == NULL)
4234         return 0;
4235     for (i = 0, sptr = sigalgs; i < salglen; i += 2) {
4236         rhash = tls12_find_id(*psig_nids++, tls12_md,
4237                               sizeof(tls12_md) / sizeof(tls12_lookup));
4238         rsign = tls12_find_id(*psig_nids++, tls12_sig,
4239                               sizeof(tls12_sig) / sizeof(tls12_lookup));
4240 
4241         if (rhash == -1 || rsign == -1)
4242             goto err;
4243         *sptr++ = rhash;
4244         *sptr++ = rsign;
4245     }
4246 
4247     if (client) {
4248         if (c->client_sigalgs)
4249             OPENSSL_free(c->client_sigalgs);
4250         c->client_sigalgs = sigalgs;
4251         c->client_sigalgslen = salglen;
4252     } else {
4253         if (c->conf_sigalgs)
4254             OPENSSL_free(c->conf_sigalgs);
4255         c->conf_sigalgs = sigalgs;
4256         c->conf_sigalgslen = salglen;
4257     }
4258 
4259     return 1;
4260 
4261  err:
4262     OPENSSL_free(sigalgs);
4263     return 0;
4264 }
4265 
4266 static int tls1_check_sig_alg(CERT *c, X509 *x, int default_nid)
4267 {
4268     int sig_nid;
4269     size_t i;
4270     if (default_nid == -1)
4271         return 1;
4272     sig_nid = X509_get_signature_nid(x);
4273     if (default_nid)
4274         return sig_nid == default_nid ? 1 : 0;
4275     for (i = 0; i < c->shared_sigalgslen; i++)
4276         if (sig_nid == c->shared_sigalgs[i].signandhash_nid)
4277             return 1;
4278     return 0;
4279 }
4280 
4281 /* Check to see if a certificate issuer name matches list of CA names */
4282 static int ssl_check_ca_name(STACK_OF(X509_NAME) *names, X509 *x)
4283 {
4284     X509_NAME *nm;
4285     int i;
4286     nm = X509_get_issuer_name(x);
4287     for (i = 0; i < sk_X509_NAME_num(names); i++) {
4288         if (!X509_NAME_cmp(nm, sk_X509_NAME_value(names, i)))
4289             return 1;
4290     }
4291     return 0;
4292 }
4293 
4294 /*
4295  * Check certificate chain is consistent with TLS extensions and is usable by
4296  * server. This servers two purposes: it allows users to check chains before
4297  * passing them to the server and it allows the server to check chains before
4298  * attempting to use them.
4299  */
4300 
4301 /* Flags which need to be set for a certificate when stict mode not set */
4302 
4303 # define CERT_PKEY_VALID_FLAGS \
4304         (CERT_PKEY_EE_SIGNATURE|CERT_PKEY_EE_PARAM)
4305 /* Strict mode flags */
4306 # define CERT_PKEY_STRICT_FLAGS \
4307          (CERT_PKEY_VALID_FLAGS|CERT_PKEY_CA_SIGNATURE|CERT_PKEY_CA_PARAM \
4308          | CERT_PKEY_ISSUER_NAME|CERT_PKEY_CERT_TYPE)
4309 
4310 int tls1_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain,
4311                      int idx)
4312 {
4313     int i;
4314     int rv = 0;
4315     int check_flags = 0, strict_mode;
4316     CERT_PKEY *cpk = NULL;
4317     CERT *c = s->cert;
4318     unsigned int suiteb_flags = tls1_suiteb(s);
4319     /* idx == -1 means checking server chains */
4320     if (idx != -1) {
4321         /* idx == -2 means checking client certificate chains */
4322         if (idx == -2) {
4323             cpk = c->key;
4324             idx = cpk - c->pkeys;
4325         } else
4326             cpk = c->pkeys + idx;
4327         x = cpk->x509;
4328         pk = cpk->privatekey;
4329         chain = cpk->chain;
4330         strict_mode = c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT;
4331         /* If no cert or key, forget it */
4332         if (!x || !pk)
4333             goto end;
4334 # ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
4335         /* Allow any certificate to pass test */
4336         if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL) {
4337             rv = CERT_PKEY_STRICT_FLAGS | CERT_PKEY_EXPLICIT_SIGN |
4338                 CERT_PKEY_VALID | CERT_PKEY_SIGN;
4339             cpk->valid_flags = rv;
4340             return rv;
4341         }
4342 # endif
4343     } else {
4344         if (!x || !pk)
4345             return 0;
4346         idx = ssl_cert_type(x, pk);
4347         if (idx == -1)
4348             return 0;
4349         cpk = c->pkeys + idx;
4350         if (c->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT)
4351             check_flags = CERT_PKEY_STRICT_FLAGS;
4352         else
4353             check_flags = CERT_PKEY_VALID_FLAGS;
4354         strict_mode = 1;
4355     }
4356 
4357     if (suiteb_flags) {
4358         int ok;
4359         if (check_flags)
4360             check_flags |= CERT_PKEY_SUITEB;
4361         ok = X509_chain_check_suiteb(NULL, x, chain, suiteb_flags);
4362         if (ok == X509_V_OK)
4363             rv |= CERT_PKEY_SUITEB;
4364         else if (!check_flags)
4365             goto end;
4366     }
4367 
4368     /*
4369      * Check all signature algorithms are consistent with signature
4370      * algorithms extension if TLS 1.2 or later and strict mode.
4371      */
4372     if (TLS1_get_version(s) >= TLS1_2_VERSION && strict_mode) {
4373         int default_nid;
4374         unsigned char rsign = 0;
4375         if (c->peer_sigalgs)
4376             default_nid = 0;
4377         /* If no sigalgs extension use defaults from RFC5246 */
4378         else {
4379             switch (idx) {
4380             case SSL_PKEY_RSA_ENC:
4381             case SSL_PKEY_RSA_SIGN:
4382             case SSL_PKEY_DH_RSA:
4383                 rsign = TLSEXT_signature_rsa;
4384                 default_nid = NID_sha1WithRSAEncryption;
4385                 break;
4386 
4387             case SSL_PKEY_DSA_SIGN:
4388             case SSL_PKEY_DH_DSA:
4389                 rsign = TLSEXT_signature_dsa;
4390                 default_nid = NID_dsaWithSHA1;
4391                 break;
4392 
4393             case SSL_PKEY_ECC:
4394                 rsign = TLSEXT_signature_ecdsa;
4395                 default_nid = NID_ecdsa_with_SHA1;
4396                 break;
4397 
4398             default:
4399                 default_nid = -1;
4400                 break;
4401             }
4402         }
4403         /*
4404          * If peer sent no signature algorithms extension and we have set
4405          * preferred signature algorithms check we support sha1.
4406          */
4407         if (default_nid > 0 && c->conf_sigalgs) {
4408             size_t j;
4409             const unsigned char *p = c->conf_sigalgs;
4410             for (j = 0; j < c->conf_sigalgslen; j += 2, p += 2) {
4411                 if (p[0] == TLSEXT_hash_sha1 && p[1] == rsign)
4412                     break;
4413             }
4414             if (j == c->conf_sigalgslen) {
4415                 if (check_flags)
4416                     goto skip_sigs;
4417                 else
4418                     goto end;
4419             }
4420         }
4421         /* Check signature algorithm of each cert in chain */
4422         if (!tls1_check_sig_alg(c, x, default_nid)) {
4423             if (!check_flags)
4424                 goto end;
4425         } else
4426             rv |= CERT_PKEY_EE_SIGNATURE;
4427         rv |= CERT_PKEY_CA_SIGNATURE;
4428         for (i = 0; i < sk_X509_num(chain); i++) {
4429             if (!tls1_check_sig_alg(c, sk_X509_value(chain, i), default_nid)) {
4430                 if (check_flags) {
4431                     rv &= ~CERT_PKEY_CA_SIGNATURE;
4432                     break;
4433                 } else
4434                     goto end;
4435             }
4436         }
4437     }
4438     /* Else not TLS 1.2, so mark EE and CA signing algorithms OK */
4439     else if (check_flags)
4440         rv |= CERT_PKEY_EE_SIGNATURE | CERT_PKEY_CA_SIGNATURE;
4441  skip_sigs:
4442     /* Check cert parameters are consistent */
4443     if (tls1_check_cert_param(s, x, check_flags ? 1 : 2))
4444         rv |= CERT_PKEY_EE_PARAM;
4445     else if (!check_flags)
4446         goto end;
4447     if (!s->server)
4448         rv |= CERT_PKEY_CA_PARAM;
4449     /* In strict mode check rest of chain too */
4450     else if (strict_mode) {
4451         rv |= CERT_PKEY_CA_PARAM;
4452         for (i = 0; i < sk_X509_num(chain); i++) {
4453             X509 *ca = sk_X509_value(chain, i);
4454             if (!tls1_check_cert_param(s, ca, 0)) {
4455                 if (check_flags) {
4456                     rv &= ~CERT_PKEY_CA_PARAM;
4457                     break;
4458                 } else
4459                     goto end;
4460             }
4461         }
4462     }
4463     if (!s->server && strict_mode) {
4464         STACK_OF(X509_NAME) *ca_dn;
4465         int check_type = 0;
4466         switch (pk->type) {
4467         case EVP_PKEY_RSA:
4468             check_type = TLS_CT_RSA_SIGN;
4469             break;
4470         case EVP_PKEY_DSA:
4471             check_type = TLS_CT_DSS_SIGN;
4472             break;
4473         case EVP_PKEY_EC:
4474             check_type = TLS_CT_ECDSA_SIGN;
4475             break;
4476         case EVP_PKEY_DH:
4477         case EVP_PKEY_DHX:
4478             {
4479                 int cert_type = X509_certificate_type(x, pk);
4480                 if (cert_type & EVP_PKS_RSA)
4481                     check_type = TLS_CT_RSA_FIXED_DH;
4482                 if (cert_type & EVP_PKS_DSA)
4483                     check_type = TLS_CT_DSS_FIXED_DH;
4484             }
4485         }
4486         if (check_type) {
4487             const unsigned char *ctypes;
4488             int ctypelen;
4489             if (c->ctypes) {
4490                 ctypes = c->ctypes;
4491                 ctypelen = (int)c->ctype_num;
4492             } else {
4493                 ctypes = (unsigned char *)s->s3->tmp.ctype;
4494                 ctypelen = s->s3->tmp.ctype_num;
4495             }
4496             for (i = 0; i < ctypelen; i++) {
4497                 if (ctypes[i] == check_type) {
4498                     rv |= CERT_PKEY_CERT_TYPE;
4499                     break;
4500                 }
4501             }
4502             if (!(rv & CERT_PKEY_CERT_TYPE) && !check_flags)
4503                 goto end;
4504         } else
4505             rv |= CERT_PKEY_CERT_TYPE;
4506 
4507         ca_dn = s->s3->tmp.ca_names;
4508 
4509         if (!sk_X509_NAME_num(ca_dn))
4510             rv |= CERT_PKEY_ISSUER_NAME;
4511 
4512         if (!(rv & CERT_PKEY_ISSUER_NAME)) {
4513             if (ssl_check_ca_name(ca_dn, x))
4514                 rv |= CERT_PKEY_ISSUER_NAME;
4515         }
4516         if (!(rv & CERT_PKEY_ISSUER_NAME)) {
4517             for (i = 0; i < sk_X509_num(chain); i++) {
4518                 X509 *xtmp = sk_X509_value(chain, i);
4519                 if (ssl_check_ca_name(ca_dn, xtmp)) {
4520                     rv |= CERT_PKEY_ISSUER_NAME;
4521                     break;
4522                 }
4523             }
4524         }
4525         if (!check_flags && !(rv & CERT_PKEY_ISSUER_NAME))
4526             goto end;
4527     } else
4528         rv |= CERT_PKEY_ISSUER_NAME | CERT_PKEY_CERT_TYPE;
4529 
4530     if (!check_flags || (rv & check_flags) == check_flags)
4531         rv |= CERT_PKEY_VALID;
4532 
4533  end:
4534 
4535     if (TLS1_get_version(s) >= TLS1_2_VERSION) {
4536         if (cpk->valid_flags & CERT_PKEY_EXPLICIT_SIGN)
4537             rv |= CERT_PKEY_EXPLICIT_SIGN | CERT_PKEY_SIGN;
4538         else if (cpk->digest)
4539             rv |= CERT_PKEY_SIGN;
4540     } else
4541         rv |= CERT_PKEY_SIGN | CERT_PKEY_EXPLICIT_SIGN;
4542 
4543     /*
4544      * When checking a CERT_PKEY structure all flags are irrelevant if the
4545      * chain is invalid.
4546      */
4547     if (!check_flags) {
4548         if (rv & CERT_PKEY_VALID)
4549             cpk->valid_flags = rv;
4550         else {
4551             /* Preserve explicit sign flag, clear rest */
4552             cpk->valid_flags &= CERT_PKEY_EXPLICIT_SIGN;
4553             return 0;
4554         }
4555     }
4556     return rv;
4557 }
4558 
4559 /* Set validity of certificates in an SSL structure */
4560 void tls1_set_cert_validity(SSL *s)
4561 {
4562     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_ENC);
4563     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_RSA_SIGN);
4564     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DSA_SIGN);
4565     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_RSA);
4566     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_DH_DSA);
4567     tls1_check_chain(s, NULL, NULL, NULL, SSL_PKEY_ECC);
4568 }
4569 
4570 /* User level utiity function to check a chain is suitable */
4571 int SSL_check_chain(SSL *s, X509 *x, EVP_PKEY *pk, STACK_OF(X509) *chain)
4572 {
4573     return tls1_check_chain(s, x, pk, chain, -1);
4574 }
4575 
4576 #endif
4577