Custom extension revision.
[openssl.git] / ssl / t1_lib.c
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) 1998-2007 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 #include <openssl/ocsp.h>
117 #include <openssl/rand.h>
118 #ifndef OPENSSL_NO_DH
119 #include <openssl/dh.h>
120 #include <openssl/bn.h>
121 #endif
122 #include "ssl_locl.h"
123
124 const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
125
126 #ifndef OPENSSL_NO_TLSEXT
127 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
128                                 const unsigned char *sess_id, int sesslen,
129                                 SSL_SESSION **psess);
130 static int ssl_check_clienthello_tlsext_early(SSL *s);
131 int ssl_check_serverhello_tlsext(SSL *s);
132 #endif
133
134 SSL3_ENC_METHOD const TLSv1_enc_data={
135         tls1_enc,
136         tls1_mac,
137         tls1_setup_key_block,
138         tls1_generate_master_secret,
139         tls1_change_cipher_state,
140         tls1_final_finish_mac,
141         TLS1_FINISH_MAC_LENGTH,
142         tls1_cert_verify_mac,
143         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
144         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
145         tls1_alert_code,
146         tls1_export_keying_material,
147         0,
148         SSL3_HM_HEADER_LENGTH,
149         ssl3_set_handshake_header,
150         ssl3_handshake_write
151         };
152
153 SSL3_ENC_METHOD const TLSv1_1_enc_data={
154         tls1_enc,
155         tls1_mac,
156         tls1_setup_key_block,
157         tls1_generate_master_secret,
158         tls1_change_cipher_state,
159         tls1_final_finish_mac,
160         TLS1_FINISH_MAC_LENGTH,
161         tls1_cert_verify_mac,
162         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
163         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
164         tls1_alert_code,
165         tls1_export_keying_material,
166         SSL_ENC_FLAG_EXPLICIT_IV,
167         SSL3_HM_HEADER_LENGTH,
168         ssl3_set_handshake_header,
169         ssl3_handshake_write
170         };
171
172 SSL3_ENC_METHOD const TLSv1_2_enc_data={
173         tls1_enc,
174         tls1_mac,
175         tls1_setup_key_block,
176         tls1_generate_master_secret,
177         tls1_change_cipher_state,
178         tls1_final_finish_mac,
179         TLS1_FINISH_MAC_LENGTH,
180         tls1_cert_verify_mac,
181         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
182         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
183         tls1_alert_code,
184         tls1_export_keying_material,
185         SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_SHA256_PRF
186                 |SSL_ENC_FLAG_TLS1_2_CIPHERS,
187         SSL3_HM_HEADER_LENGTH,
188         ssl3_set_handshake_header,
189         ssl3_handshake_write
190         };
191
192 long tls1_default_timeout(void)
193         {
194         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
195          * is way too long for http, the cache would over fill */
196         return(60*60*2);
197         }
198
199 int tls1_new(SSL *s)
200         {
201         if (!ssl3_new(s)) return(0);
202         s->method->ssl_clear(s);
203         return(1);
204         }
205
206 void tls1_free(SSL *s)
207         {
208 #ifndef OPENSSL_NO_TLSEXT
209         if (s->tlsext_session_ticket)
210                 {
211                 OPENSSL_free(s->tlsext_session_ticket);
212                 }
213 #endif /* OPENSSL_NO_TLSEXT */
214         ssl3_free(s);
215         }
216
217 void tls1_clear(SSL *s)
218         {
219         ssl3_clear(s);
220         s->version = s->method->version;
221         }
222
223 #ifndef OPENSSL_NO_EC
224
225 typedef struct
226         {
227         int nid;                /* Curve NID */
228         int secbits;            /* Bits of security (from SP800-57) */
229         unsigned int flags;     /* Flags: currently just field type */
230         } tls_curve_info;
231
232 #define TLS_CURVE_CHAR2         0x1
233 #define TLS_CURVE_PRIME         0x0
234
235 static const tls_curve_info nid_list[] =
236         {
237                 {NID_sect163k1, 80, TLS_CURVE_CHAR2},/* sect163k1 (1) */
238                 {NID_sect163r1, 80, TLS_CURVE_CHAR2},/* sect163r1 (2) */
239                 {NID_sect163r2, 80, TLS_CURVE_CHAR2},/* sect163r2 (3) */
240                 {NID_sect193r1, 80, TLS_CURVE_CHAR2},/* sect193r1 (4) */ 
241                 {NID_sect193r2, 80, TLS_CURVE_CHAR2},/* sect193r2 (5) */ 
242                 {NID_sect233k1, 112, TLS_CURVE_CHAR2},/* sect233k1 (6) */
243                 {NID_sect233r1, 112, TLS_CURVE_CHAR2},/* sect233r1 (7) */ 
244                 {NID_sect239k1, 112, TLS_CURVE_CHAR2},/* sect239k1 (8) */ 
245                 {NID_sect283k1, 128, TLS_CURVE_CHAR2},/* sect283k1 (9) */
246                 {NID_sect283r1, 128, TLS_CURVE_CHAR2},/* sect283r1 (10) */ 
247                 {NID_sect409k1, 192, TLS_CURVE_CHAR2},/* sect409k1 (11) */ 
248                 {NID_sect409r1, 192, TLS_CURVE_CHAR2},/* sect409r1 (12) */
249                 {NID_sect571k1, 256, TLS_CURVE_CHAR2},/* sect571k1 (13) */ 
250                 {NID_sect571r1, 256, TLS_CURVE_CHAR2},/* sect571r1 (14) */ 
251                 {NID_secp160k1, 80, TLS_CURVE_PRIME},/* secp160k1 (15) */
252                 {NID_secp160r1, 80, TLS_CURVE_PRIME},/* secp160r1 (16) */ 
253                 {NID_secp160r2, 80, TLS_CURVE_PRIME},/* secp160r2 (17) */ 
254                 {NID_secp192k1, 80, TLS_CURVE_PRIME},/* secp192k1 (18) */
255                 {NID_X9_62_prime192v1, 80, TLS_CURVE_PRIME},/* secp192r1 (19) */ 
256                 {NID_secp224k1, 112, TLS_CURVE_PRIME},/* secp224k1 (20) */ 
257                 {NID_secp224r1, 112, TLS_CURVE_PRIME},/* secp224r1 (21) */
258                 {NID_secp256k1, 128, TLS_CURVE_PRIME},/* secp256k1 (22) */ 
259                 {NID_X9_62_prime256v1, 128, TLS_CURVE_PRIME},/* secp256r1 (23) */ 
260                 {NID_secp384r1, 192, TLS_CURVE_PRIME},/* secp384r1 (24) */
261                 {NID_secp521r1, 256, TLS_CURVE_PRIME},/* secp521r1 (25) */      
262                 {NID_brainpoolP256r1, 128, TLS_CURVE_PRIME}, /* brainpoolP256r1 (26) */ 
263                 {NID_brainpoolP384r1, 192, TLS_CURVE_PRIME}, /* brainpoolP384r1 (27) */ 
264                 {NID_brainpoolP512r1, 256, TLS_CURVE_PRIME},/* brainpool512r1 (28) */   
265         };
266
267
268 static const unsigned char ecformats_default[] = 
269         {
270         TLSEXT_ECPOINTFORMAT_uncompressed,
271         TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
272         TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
273         };
274
275 static const unsigned char eccurves_default[] =
276         {
277                 0,14, /* sect571r1 (14) */ 
278                 0,13, /* sect571k1 (13) */ 
279                 0,25, /* secp521r1 (25) */      
280                 0,28, /* brainpool512r1 (28) */ 
281                 0,11, /* sect409k1 (11) */ 
282                 0,12, /* sect409r1 (12) */
283                 0,27, /* brainpoolP384r1 (27) */        
284                 0,24, /* secp384r1 (24) */
285                 0,9,  /* sect283k1 (9) */
286                 0,10, /* sect283r1 (10) */ 
287                 0,26, /* brainpoolP256r1 (26) */        
288                 0,22, /* secp256k1 (22) */ 
289                 0,23, /* secp256r1 (23) */ 
290                 0,8,  /* sect239k1 (8) */ 
291                 0,6,  /* sect233k1 (6) */
292                 0,7,  /* sect233r1 (7) */ 
293                 0,20, /* secp224k1 (20) */ 
294                 0,21, /* secp224r1 (21) */
295                 0,4,  /* sect193r1 (4) */ 
296                 0,5,  /* sect193r2 (5) */ 
297                 0,18, /* secp192k1 (18) */
298                 0,19, /* secp192r1 (19) */ 
299                 0,1,  /* sect163k1 (1) */
300                 0,2,  /* sect163r1 (2) */
301                 0,3,  /* sect163r2 (3) */
302                 0,15, /* secp160k1 (15) */
303                 0,16, /* secp160r1 (16) */ 
304                 0,17, /* secp160r2 (17) */ 
305         };
306
307 static const unsigned char suiteb_curves[] =
308         {
309                 0, TLSEXT_curve_P_256,
310                 0, TLSEXT_curve_P_384
311         };
312
313 int tls1_ec_curve_id2nid(int curve_id)
314         {
315         /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
316         if ((curve_id < 1) || ((unsigned int)curve_id >
317                                 sizeof(nid_list)/sizeof(nid_list[0])))
318                 return 0;
319         return nid_list[curve_id-1].nid;
320         }
321
322 int tls1_ec_nid2curve_id(int nid)
323         {
324         /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
325         switch (nid)
326                 {
327         case NID_sect163k1: /* sect163k1 (1) */
328                 return 1;
329         case NID_sect163r1: /* sect163r1 (2) */
330                 return 2;
331         case NID_sect163r2: /* sect163r2 (3) */
332                 return 3;
333         case NID_sect193r1: /* sect193r1 (4) */ 
334                 return 4;
335         case NID_sect193r2: /* sect193r2 (5) */ 
336                 return 5;
337         case NID_sect233k1: /* sect233k1 (6) */
338                 return 6;
339         case NID_sect233r1: /* sect233r1 (7) */ 
340                 return 7;
341         case NID_sect239k1: /* sect239k1 (8) */ 
342                 return 8;
343         case NID_sect283k1: /* sect283k1 (9) */
344                 return 9;
345         case NID_sect283r1: /* sect283r1 (10) */ 
346                 return 10;
347         case NID_sect409k1: /* sect409k1 (11) */ 
348                 return 11;
349         case NID_sect409r1: /* sect409r1 (12) */
350                 return 12;
351         case NID_sect571k1: /* sect571k1 (13) */ 
352                 return 13;
353         case NID_sect571r1: /* sect571r1 (14) */ 
354                 return 14;
355         case NID_secp160k1: /* secp160k1 (15) */
356                 return 15;
357         case NID_secp160r1: /* secp160r1 (16) */ 
358                 return 16;
359         case NID_secp160r2: /* secp160r2 (17) */ 
360                 return 17;
361         case NID_secp192k1: /* secp192k1 (18) */
362                 return 18;
363         case NID_X9_62_prime192v1: /* secp192r1 (19) */ 
364                 return 19;
365         case NID_secp224k1: /* secp224k1 (20) */ 
366                 return 20;
367         case NID_secp224r1: /* secp224r1 (21) */
368                 return 21;
369         case NID_secp256k1: /* secp256k1 (22) */ 
370                 return 22;
371         case NID_X9_62_prime256v1: /* secp256r1 (23) */ 
372                 return 23;
373         case NID_secp384r1: /* secp384r1 (24) */
374                 return 24;
375         case NID_secp521r1:  /* secp521r1 (25) */       
376                 return 25;
377         case NID_brainpoolP256r1:  /* brainpoolP256r1 (26) */
378                 return 26;
379         case NID_brainpoolP384r1:  /* brainpoolP384r1 (27) */
380                 return 27;
381         case NID_brainpoolP512r1:  /* brainpool512r1 (28) */
382                 return 28;
383         default:
384                 return 0;
385                 }
386         }
387 /* Get curves list, if "sess" is set return client curves otherwise
388  * preferred list
389  */
390 static void tls1_get_curvelist(SSL *s, int sess,
391                                         const unsigned char **pcurves,
392                                         size_t *pcurveslen)
393         {
394         if (sess)
395                 {
396                 *pcurves = s->session->tlsext_ellipticcurvelist;
397                 *pcurveslen = s->session->tlsext_ellipticcurvelist_length;
398                 return;
399                 }
400         /* For Suite B mode only include P-256, P-384 */
401         switch (tls1_suiteb(s))
402                 {
403         case SSL_CERT_FLAG_SUITEB_128_LOS:
404                 *pcurves = suiteb_curves;
405                 *pcurveslen = sizeof(suiteb_curves);
406                 break;
407
408         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
409                 *pcurves = suiteb_curves;
410                 *pcurveslen = 2;
411                 break;
412
413         case SSL_CERT_FLAG_SUITEB_192_LOS:
414                 *pcurves = suiteb_curves + 2;
415                 *pcurveslen = 2;
416                 break;
417         default:
418                 *pcurves = s->tlsext_ellipticcurvelist;
419                 *pcurveslen = s->tlsext_ellipticcurvelist_length;
420                 }
421         if (!*pcurves)
422                 {
423                 *pcurves = eccurves_default;
424                 *pcurveslen = sizeof(eccurves_default);
425                 }
426         }
427
428 /* See if curve is allowed by security callback */
429 static int tls_curve_allowed(SSL *s, const unsigned char *curve, int op)
430         {
431         const tls_curve_info *cinfo;
432         if (curve[0])
433                 return 1;
434         if ((curve[1] < 1) || ((size_t)curve[1] >
435                                 sizeof(nid_list)/sizeof(nid_list[0])))
436                 return 0;
437         cinfo = &nid_list[curve[1]-1];
438         return ssl_security(s, op, cinfo->secbits, cinfo->nid, (void *)curve);
439         }
440
441 /* Check a curve is one of our preferences */
442 int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
443         {
444         const unsigned char *curves;
445         size_t curveslen, i;
446         unsigned int suiteb_flags = tls1_suiteb(s);
447         if (len != 3 || p[0] != NAMED_CURVE_TYPE)
448                 return 0;
449         /* Check curve matches Suite B preferences */
450         if (suiteb_flags)
451                 {
452                 unsigned long cid = s->s3->tmp.new_cipher->id;
453                 if (p[1])
454                         return 0;
455                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
456                         {
457                         if (p[2] != TLSEXT_curve_P_256)
458                                 return 0;
459                         }
460                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
461                         {
462                         if (p[2] != TLSEXT_curve_P_384)
463                                 return 0;
464                         }
465                 else    /* Should never happen */
466                         return 0;
467                 }
468         tls1_get_curvelist(s, 0, &curves, &curveslen);
469         for (i = 0; i < curveslen; i += 2, curves += 2)
470                 {
471                 if (p[1] == curves[0] && p[2] == curves[1])
472                         return tls_curve_allowed(s, p + 1, SSL_SECOP_CURVE_CHECK);
473                 }
474         return 0;
475         }
476
477 /* Return nth shared curve. If nmatch == -1 return number of
478  * matches. For nmatch == -2 return the NID of the curve to use for
479  * an EC tmp key.
480  */
481
482 int tls1_shared_curve(SSL *s, int nmatch)
483         {
484         const unsigned char *pref, *supp;
485         size_t preflen, supplen, i, j;
486         int k;
487         /* Can't do anything on client side */
488         if (s->server == 0)
489                 return -1;
490         if (nmatch == -2)
491                 {
492                 if (tls1_suiteb(s))
493                         {
494                         /* For Suite B ciphersuite determines curve: we 
495                          * already know these are acceptable due to previous
496                          * checks.
497                          */
498                         unsigned long cid = s->s3->tmp.new_cipher->id;
499                         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
500                                 return NID_X9_62_prime256v1; /* P-256 */
501                         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
502                                 return NID_secp384r1; /* P-384 */
503                         /* Should never happen */
504                         return NID_undef;
505                         }
506                 /* If not Suite B just return first preference shared curve */
507                 nmatch = 0;
508                 }
509         tls1_get_curvelist(s, !!(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
510                                 &supp, &supplen);
511         tls1_get_curvelist(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
512                                 &pref, &preflen);
513         preflen /= 2;
514         supplen /= 2;
515         k = 0;
516         for (i = 0; i < preflen; i++, pref+=2)
517                 {
518                 const unsigned char *tsupp = supp;
519                 for (j = 0; j < supplen; j++, tsupp+=2)
520                         {
521                         if (pref[0] == tsupp[0] && pref[1] == tsupp[1])
522                                 {
523                                 if (!tls_curve_allowed(s, pref, SSL_SECOP_CURVE_SHARED))
524                                         continue;
525                                 if (nmatch == k)
526                                         {
527                                         int id = (pref[0] << 8) | pref[1];
528                                         return tls1_ec_curve_id2nid(id);
529                                         }
530                                 k++;
531                                 }
532                         }
533                 }
534         if (nmatch == -1)
535                 return k;
536         return 0;
537         }
538
539 int tls1_set_curves(unsigned char **pext, size_t *pextlen,
540                         int *curves, size_t ncurves)
541         {
542         unsigned char *clist, *p;
543         size_t i;
544         /* Bitmap of curves included to detect duplicates: only works
545          * while curve ids < 32 
546          */
547         unsigned long dup_list = 0;
548         clist = OPENSSL_malloc(ncurves * 2);
549         if (!clist)
550                 return 0;
551         for (i = 0, p = clist; i < ncurves; i++)
552                 {
553                 unsigned long idmask;
554                 int id;
555                 id = tls1_ec_nid2curve_id(curves[i]);
556                 idmask = 1L << id;
557                 if (!id || (dup_list & idmask))
558                         {
559                         OPENSSL_free(clist);
560                         return 0;
561                         }
562                 dup_list |= idmask;
563                 s2n(id, p);
564                 }
565         if (*pext)
566                 OPENSSL_free(*pext);
567         *pext = clist;
568         *pextlen = ncurves * 2;
569         return 1;
570         }
571
572 #define MAX_CURVELIST   28
573
574 typedef struct
575         {
576         size_t nidcnt;
577         int nid_arr[MAX_CURVELIST];
578         } nid_cb_st;
579
580 static int nid_cb(const char *elem, int len, void *arg)
581         {
582         nid_cb_st *narg = arg;
583         size_t i;
584         int nid;
585         char etmp[20];
586         if (narg->nidcnt == MAX_CURVELIST)
587                 return 0;
588         if (len > (int)(sizeof(etmp) - 1))
589                 return 0;
590         memcpy(etmp, elem, len);
591         etmp[len] = 0;
592         nid = EC_curve_nist2nid(etmp);
593         if (nid == NID_undef)
594                 nid = OBJ_sn2nid(etmp);
595         if (nid == NID_undef)
596                 nid = OBJ_ln2nid(etmp);
597         if (nid == NID_undef)
598                 return 0;
599         for (i = 0; i < narg->nidcnt; i++)
600                 if (narg->nid_arr[i] == nid)
601                         return 0;
602         narg->nid_arr[narg->nidcnt++] = nid;
603         return 1;
604         }
605 /* Set curves based on a colon separate list */
606 int tls1_set_curves_list(unsigned char **pext, size_t *pextlen, 
607                                 const char *str)
608         {
609         nid_cb_st ncb;
610         ncb.nidcnt = 0;
611         if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
612                 return 0;
613         if (pext == NULL)
614                 return 1;
615         return tls1_set_curves(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
616         }
617 /* For an EC key set TLS id and required compression based on parameters */
618 static int tls1_set_ec_id(unsigned char *curve_id, unsigned char *comp_id,
619                                 EC_KEY *ec)
620         {
621         int is_prime, id;
622         const EC_GROUP *grp;
623         const EC_METHOD *meth;
624         if (!ec)
625                 return 0;
626         /* Determine if it is a prime field */
627         grp = EC_KEY_get0_group(ec);
628         if (!grp)
629                 return 0;
630         meth = EC_GROUP_method_of(grp);
631         if (!meth)
632                 return 0;
633         if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field)
634                 is_prime = 1;
635         else
636                 is_prime = 0;
637         /* Determine curve ID */
638         id = EC_GROUP_get_curve_name(grp);
639         id = tls1_ec_nid2curve_id(id);
640         /* If we have an ID set it, otherwise set arbitrary explicit curve */
641         if (id)
642                 {
643                 curve_id[0] = 0;
644                 curve_id[1] = (unsigned char)id;
645                 }
646         else
647                 {
648                 curve_id[0] = 0xff;
649                 if (is_prime)
650                         curve_id[1] = 0x01;
651                 else
652                         curve_id[1] = 0x02;
653                 }
654         if (comp_id)
655                 {
656                 if (EC_KEY_get0_public_key(ec) == NULL)
657                         return 0;
658                 if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED)
659                         {
660                         if (is_prime)
661                                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
662                         else
663                                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
664                         }
665                 else
666                         *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
667                 }
668         return 1;
669         }
670 /* Check an EC key is compatible with extensions */
671 static int tls1_check_ec_key(SSL *s,
672                         unsigned char *curve_id, unsigned char *comp_id)
673         {
674         const unsigned char *p;
675         size_t plen, i;
676         int j;
677         /* If point formats extension present check it, otherwise everything
678          * is supported (see RFC4492).
679          */
680         if (comp_id && s->session->tlsext_ecpointformatlist)
681                 {
682                 p = s->session->tlsext_ecpointformatlist;
683                 plen = s->session->tlsext_ecpointformatlist_length;
684                 for (i = 0; i < plen; i++, p++)
685                         {
686                         if (*comp_id == *p)
687                                 break;
688                         }
689                 if (i == plen)
690                         return 0;
691                 }
692         if (!curve_id)
693                 return 1;
694         /* Check curve is consistent with client and server preferences */
695         for (j = 0; j <= 1; j++)
696                 {
697                 tls1_get_curvelist(s, j, &p, &plen);
698                 for (i = 0; i < plen; i+=2, p+=2)
699                         {
700                         if (p[0] == curve_id[0] && p[1] == curve_id[1])
701                                 break;
702                         }
703                 if (i == plen)
704                         return 0;
705                 /* For clients can only check sent curve list */
706                 if (!s->server)
707                         break;
708                 }
709         return 1;
710         }
711
712 static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
713                                         size_t *pformatslen)
714         {
715         /* If we have a custom point format list use it otherwise
716          * use default */
717         if (s->tlsext_ecpointformatlist)
718                 {
719                 *pformats = s->tlsext_ecpointformatlist;
720                 *pformatslen = s->tlsext_ecpointformatlist_length;
721                 }
722         else
723                 {
724                 *pformats = ecformats_default;
725                 /* For Suite B we don't support char2 fields */
726                 if (tls1_suiteb(s))
727                         *pformatslen = sizeof(ecformats_default) - 1;
728                 else
729                         *pformatslen = sizeof(ecformats_default);
730                 }
731         }
732
733 /* Check cert parameters compatible with extensions: currently just checks
734  * EC certificates have compatible curves and compression.
735  */
736 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
737         {
738         unsigned char comp_id, curve_id[2];
739         EVP_PKEY *pkey;
740         int rv;
741         pkey = X509_get_pubkey(x);
742         if (!pkey)
743                 return 0;
744         /* If not EC nothing to do */
745         if (pkey->type != EVP_PKEY_EC)
746                 {
747                 EVP_PKEY_free(pkey);
748                 return 1;
749                 }
750         rv = tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec);
751         EVP_PKEY_free(pkey);
752         if (!rv)
753                 return 0;
754         /* Can't check curve_id for client certs as we don't have a
755          * supported curves extension.
756          */
757         rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
758         if (!rv)
759                 return 0;
760         /* Special case for suite B. We *MUST* sign using SHA256+P-256 or
761          * SHA384+P-384, adjust digest if necessary.
762          */
763         if (set_ee_md && tls1_suiteb(s))
764                 {
765                 int check_md;
766                 size_t i;
767                 CERT *c = s->cert;
768                 if (curve_id[0])
769                         return 0;
770                 /* Check to see we have necessary signing algorithm */
771                 if (curve_id[1] == TLSEXT_curve_P_256)
772                         check_md = NID_ecdsa_with_SHA256;
773                 else if (curve_id[1] == TLSEXT_curve_P_384)
774                         check_md = NID_ecdsa_with_SHA384;
775                 else
776                         return 0; /* Should never happen */
777                 for (i = 0; i < c->shared_sigalgslen; i++)
778                         if (check_md == c->shared_sigalgs[i].signandhash_nid)
779                                 break;
780                 if (i == c->shared_sigalgslen)
781                         return 0;
782                 if (set_ee_md == 2)
783                         {
784                         if (check_md == NID_ecdsa_with_SHA256)
785                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
786                         else
787                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
788                         }
789                 }
790         return rv;
791         }
792 /* Check EC temporary key is compatible with client extensions */
793 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
794         {
795         unsigned char curve_id[2];
796         EC_KEY *ec = s->cert->ecdh_tmp;
797 #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
798         /* Allow any curve: not just those peer supports */
799         if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
800                 return 1;
801 #endif
802         /* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384,
803          * no other curves permitted.
804          */
805         if (tls1_suiteb(s))
806                 {
807                 /* Curve to check determined by ciphersuite */
808                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
809                         curve_id[1] = TLSEXT_curve_P_256;
810                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
811                         curve_id[1] = TLSEXT_curve_P_384;
812                 else
813                         return 0;
814                 curve_id[0] = 0;
815                 /* Check this curve is acceptable */
816                 if (!tls1_check_ec_key(s, curve_id, NULL))
817                         return 0;
818                 /* If auto or setting curve from callback assume OK */
819                 if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
820                         return 1;
821                 /* Otherwise check curve is acceptable */
822                 else 
823                         {
824                         unsigned char curve_tmp[2];
825                         if (!ec)
826                                 return 0;
827                         if (!tls1_set_ec_id(curve_tmp, NULL, ec))
828                                 return 0;
829                         if (!curve_tmp[0] || curve_tmp[1] == curve_id[1])
830                                 return 1;
831                         return 0;
832                         }
833                         
834                 }
835         if (s->cert->ecdh_tmp_auto)
836                 {
837                 /* Need a shared curve */
838                 if (tls1_shared_curve(s, 0))
839                         return 1;
840                 else return 0;
841                 }
842         if (!ec)
843                 {
844                 if (s->cert->ecdh_tmp_cb)
845                         return 1;
846                 else
847                         return 0;
848                 }
849         if (!tls1_set_ec_id(curve_id, NULL, ec))
850                 return 0;
851 /* Set this to allow use of invalid curves for testing */
852 #if 0
853         return 1;
854 #else
855         return tls1_check_ec_key(s, curve_id, NULL);
856 #endif
857         }
858
859 #else
860
861 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
862         {
863         return 1;
864         }
865
866 #endif /* OPENSSL_NO_EC */
867
868 #ifndef OPENSSL_NO_TLSEXT
869
870 /* List of supported signature algorithms and hashes. Should make this
871  * customisable at some point, for now include everything we support.
872  */
873
874 #ifdef OPENSSL_NO_RSA
875 #define tlsext_sigalg_rsa(md) /* */
876 #else
877 #define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
878 #endif
879
880 #ifdef OPENSSL_NO_DSA
881 #define tlsext_sigalg_dsa(md) /* */
882 #else
883 #define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
884 #endif
885
886 #ifdef OPENSSL_NO_ECDSA
887 #define tlsext_sigalg_ecdsa(md) /* */
888 #else
889 #define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
890 #endif
891
892 #define tlsext_sigalg(md) \
893                 tlsext_sigalg_rsa(md) \
894                 tlsext_sigalg_dsa(md) \
895                 tlsext_sigalg_ecdsa(md)
896
897 static unsigned char tls12_sigalgs[] = {
898 #ifndef OPENSSL_NO_SHA512
899         tlsext_sigalg(TLSEXT_hash_sha512)
900         tlsext_sigalg(TLSEXT_hash_sha384)
901 #endif
902 #ifndef OPENSSL_NO_SHA256
903         tlsext_sigalg(TLSEXT_hash_sha256)
904         tlsext_sigalg(TLSEXT_hash_sha224)
905 #endif
906 #ifndef OPENSSL_NO_SHA
907         tlsext_sigalg(TLSEXT_hash_sha1)
908 #endif
909 };
910 #ifndef OPENSSL_NO_ECDSA
911 static unsigned char suiteb_sigalgs[] = {
912         tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
913         tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
914 };
915 #endif
916 size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
917         {
918         /* If Suite B mode use Suite B sigalgs only, ignore any other
919          * preferences.
920          */
921 #ifndef OPENSSL_NO_EC
922         switch (tls1_suiteb(s))
923                 {
924         case SSL_CERT_FLAG_SUITEB_128_LOS:
925                 *psigs = suiteb_sigalgs;
926                 return sizeof(suiteb_sigalgs);
927
928         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
929                 *psigs = suiteb_sigalgs;
930                 return 2;
931
932         case SSL_CERT_FLAG_SUITEB_192_LOS:
933                 *psigs = suiteb_sigalgs + 2;
934                 return 2;
935                 }
936 #endif
937         /* If server use client authentication sigalgs if not NULL */
938         if (s->server && s->cert->client_sigalgs)
939                 {
940                 *psigs = s->cert->client_sigalgs;
941                 return s->cert->client_sigalgslen;
942                 }
943         else if (s->cert->conf_sigalgs)
944                 {
945                 *psigs = s->cert->conf_sigalgs;
946                 return s->cert->conf_sigalgslen;
947                 }
948         else
949                 {
950                 *psigs = tls12_sigalgs;
951                 return sizeof(tls12_sigalgs);
952                 }
953         }
954 /* Check signature algorithm is consistent with sent supported signature
955  * algorithms and if so return relevant digest.
956  */
957 int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
958                                 const unsigned char *sig, EVP_PKEY *pkey)
959         {
960         const unsigned char *sent_sigs;
961         size_t sent_sigslen, i;
962         int sigalg = tls12_get_sigid(pkey);
963         /* Should never happen */
964         if (sigalg == -1)
965                 return -1;
966         /* Check key type is consistent with signature */
967         if (sigalg != (int)sig[1])
968                 {
969                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
970                 return 0;
971                 }
972 #ifndef OPENSSL_NO_EC
973         if (pkey->type == EVP_PKEY_EC)
974                 {
975                 unsigned char curve_id[2], comp_id;
976                 /* Check compression and curve matches extensions */
977                 if (!tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec))
978                         return 0;
979                 if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id))
980                         {
981                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_CURVE);
982                         return 0;
983                         }
984                 /* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
985                 if (tls1_suiteb(s))
986                         {
987                         if (curve_id[0])
988                                 return 0;
989                         if (curve_id[1] == TLSEXT_curve_P_256)
990                                 {
991                                 if (sig[0] != TLSEXT_hash_sha256)
992                                         {
993                                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
994                                                 SSL_R_ILLEGAL_SUITEB_DIGEST);
995                                         return 0;
996                                         }
997                                 }
998                         else if (curve_id[1] == TLSEXT_curve_P_384)
999                                 {
1000                                 if (sig[0] != TLSEXT_hash_sha384)
1001                                         {
1002                                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
1003                                                 SSL_R_ILLEGAL_SUITEB_DIGEST);
1004                                         return 0;
1005                                         }
1006                                 }
1007                         else
1008                                 return 0;
1009                         }
1010                 }
1011         else if (tls1_suiteb(s))
1012                 return 0;
1013 #endif
1014
1015         /* Check signature matches a type we sent */
1016         sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
1017         for (i = 0; i < sent_sigslen; i+=2, sent_sigs+=2)
1018                 {
1019                 if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
1020                         break;
1021                 }
1022         /* Allow fallback to SHA1 if not strict mode */
1023         if (i == sent_sigslen && (sig[0] != TLSEXT_hash_sha1 || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
1024                 {
1025                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
1026                 return 0;
1027                 }
1028         *pmd = tls12_get_hash(sig[0]);
1029         if (*pmd == NULL)
1030                 {
1031                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_UNKNOWN_DIGEST);
1032                 return 0;
1033                 }
1034         /* Make sure security callback allows algorithm */
1035         if (!ssl_security(s, SSL_SECOP_SIGALG_CHECK,
1036                                 EVP_MD_size(*pmd) * 4, EVP_MD_type(*pmd),
1037                                                                 (void *)sig))
1038                 {
1039                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
1040                 return 0;
1041                 }
1042         /* Store the digest used so applications can retrieve it if they
1043          * wish.
1044          */
1045         if (s->session && s->session->sess_cert)
1046                 s->session->sess_cert->peer_key->digest = *pmd;
1047         return 1;
1048         }
1049
1050 /* Get a mask of disabled algorithms: an algorithm is disabled
1051  * if it isn't supported or doesn't appear in supported signature
1052  * algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
1053  * session and not global settings.
1054  * 
1055  */
1056 void ssl_set_client_disabled(SSL *s)
1057         {
1058         CERT *c = s->cert;
1059         c->mask_a = 0;
1060         c->mask_k = 0;
1061         /* Don't allow TLS 1.2 only ciphers if we don't suppport them */
1062         if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s))
1063                 c->mask_ssl = SSL_TLSV1_2;
1064         else
1065                 c->mask_ssl = 0;
1066         ssl_set_sig_mask(&c->mask_a, s, SSL_SECOP_SIGALG_MASK);
1067         /* Disable static DH if we don't include any appropriate
1068          * signature algorithms.
1069          */
1070         if (c->mask_a & SSL_aRSA)
1071                 c->mask_k |= SSL_kDHr|SSL_kECDHr;
1072         if (c->mask_a & SSL_aDSS)
1073                 c->mask_k |= SSL_kDHd;
1074         if (c->mask_a & SSL_aECDSA)
1075                 c->mask_k |= SSL_kECDHe;
1076 #ifndef OPENSSL_NO_KRB5
1077         if (!kssl_tgt_is_available(s->kssl_ctx))
1078                 {
1079                 c->mask_a |= SSL_aKRB5;
1080                 c->mask_k |= SSL_kKRB5;
1081                 }
1082 #endif
1083 #ifndef OPENSSL_NO_PSK
1084         /* with PSK there must be client callback set */
1085         if (!s->psk_client_callback)
1086                 {
1087                 c->mask_a |= SSL_aPSK;
1088                 c->mask_k |= SSL_kPSK;
1089                 }
1090 #endif /* OPENSSL_NO_PSK */
1091 #ifndef OPENSSL_NO_SRP
1092         if (!(s->srp_ctx.srp_Mask & SSL_kSRP))
1093                 {
1094                 c->mask_a |= SSL_aSRP;
1095                 c->mask_k |= SSL_kSRP;
1096                 }
1097 #endif
1098         c->valid = 1;
1099         }
1100
1101 int ssl_cipher_disabled(SSL *s, const SSL_CIPHER *c, int op)
1102         {
1103         CERT *ct = s->cert;
1104         if (c->algorithm_ssl & ct->mask_ssl || c->algorithm_mkey & ct->mask_k || c->algorithm_auth & ct->mask_a)
1105                 return 1;
1106         return !ssl_security(s, op, c->strength_bits, 0, (void *)c);
1107         }
1108
1109 static int tls_use_ticket(SSL *s)
1110         {
1111         if (s->options & SSL_OP_NO_TICKET)
1112                 return 0;
1113         return ssl_security(s, SSL_SECOP_TICKET, 0, 0, NULL);
1114         }
1115
1116 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, int *al)
1117         {
1118         int extdatalen=0;
1119         unsigned char *orig = buf;
1120         unsigned char *ret = buf;
1121 #ifndef OPENSSL_NO_EC
1122         /* See if we support any ECC ciphersuites */
1123         int using_ecc = 0;
1124         if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s))
1125                 {
1126                 int i;
1127                 unsigned long alg_k, alg_a;
1128                 STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
1129
1130                 for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++)
1131                         {
1132                         SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
1133
1134                         alg_k = c->algorithm_mkey;
1135                         alg_a = c->algorithm_auth;
1136                         if ((alg_k & (SSL_kECDHE|SSL_kECDHr|SSL_kECDHe)
1137                                 || (alg_a & SSL_aECDSA)))
1138                                 {
1139                                 using_ecc = 1;
1140                                 break;
1141                                 }
1142                         }
1143                 }
1144 #endif
1145
1146         /* don't add extensions for SSLv3 unless doing secure renegotiation */
1147         if (s->client_version == SSL3_VERSION
1148                                         && !s->s3->send_connection_binding)
1149                 return orig;
1150
1151         ret+=2;
1152
1153         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1154
1155         if (s->tlsext_hostname != NULL)
1156                 { 
1157                 /* Add TLS extension servername to the Client Hello message */
1158                 unsigned long size_str;
1159                 long lenmax; 
1160
1161                 /* check for enough space.
1162                    4 for the servername type and entension length
1163                    2 for servernamelist length
1164                    1 for the hostname type
1165                    2 for hostname length
1166                    + hostname length 
1167                 */
1168                    
1169                 if ((lenmax = limit - ret - 9) < 0 
1170                     || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax) 
1171                         return NULL;
1172                         
1173                 /* extension type and length */
1174                 s2n(TLSEXT_TYPE_server_name,ret); 
1175                 s2n(size_str+5,ret);
1176                 
1177                 /* length of servername list */
1178                 s2n(size_str+3,ret);
1179         
1180                 /* hostname type, length and hostname */
1181                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
1182                 s2n(size_str,ret);
1183                 memcpy(ret, s->tlsext_hostname, size_str);
1184                 ret+=size_str;
1185                 }
1186
1187         /* Add RI if renegotiating */
1188         if (s->renegotiate)
1189           {
1190           int el;
1191           
1192           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
1193               {
1194               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1195               return NULL;
1196               }
1197
1198           if((limit - ret - 4 - el) < 0) return NULL;
1199           
1200           s2n(TLSEXT_TYPE_renegotiate,ret);
1201           s2n(el,ret);
1202
1203           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
1204               {
1205               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1206               return NULL;
1207               }
1208
1209           ret += el;
1210         }
1211
1212 #ifndef OPENSSL_NO_SRP
1213         /* Add SRP username if there is one */
1214         if (s->srp_ctx.login != NULL)
1215                 { /* Add TLS extension SRP username to the Client Hello message */
1216
1217                 int login_len = strlen(s->srp_ctx.login);       
1218                 if (login_len > 255 || login_len == 0)
1219                         {
1220                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1221                         return NULL;
1222                         } 
1223
1224                 /* check for enough space.
1225                    4 for the srp type type and entension length
1226                    1 for the srp user identity
1227                    + srp user identity length 
1228                 */
1229                 if ((limit - ret - 5 - login_len) < 0) return NULL; 
1230
1231                 /* fill in the extension */
1232                 s2n(TLSEXT_TYPE_srp,ret);
1233                 s2n(login_len+1,ret);
1234                 (*ret++) = (unsigned char) login_len;
1235                 memcpy(ret, s->srp_ctx.login, login_len);
1236                 ret+=login_len;
1237                 }
1238 #endif
1239
1240 #ifndef OPENSSL_NO_EC
1241         if (using_ecc)
1242                 {
1243                 /* Add TLS extension ECPointFormats to the ClientHello message */
1244                 long lenmax; 
1245                 const unsigned char *plist;
1246                 size_t plistlen;
1247                 size_t i;
1248                 unsigned char *etmp;
1249
1250                 tls1_get_formatlist(s, &plist, &plistlen);
1251
1252                 if ((lenmax = limit - ret - 5) < 0) return NULL; 
1253                 if (plistlen > (size_t)lenmax) return NULL;
1254                 if (plistlen > 255)
1255                         {
1256                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1257                         return NULL;
1258                         }
1259                 
1260                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1261                 s2n(plistlen + 1,ret);
1262                 *(ret++) = (unsigned char)plistlen ;
1263                 memcpy(ret, plist, plistlen);
1264                 ret+=plistlen;
1265
1266                 /* Add TLS extension EllipticCurves to the ClientHello message */
1267                 plist = s->tlsext_ellipticcurvelist;
1268                 tls1_get_curvelist(s, 0, &plist, &plistlen);
1269
1270                 if ((lenmax = limit - ret - 6) < 0) return NULL; 
1271                 if (plistlen > (size_t)lenmax) return NULL;
1272                 if (plistlen > 65532)
1273                         {
1274                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1275                         return NULL;
1276                         }
1277
1278                 
1279                 s2n(TLSEXT_TYPE_elliptic_curves,ret);
1280                 etmp = ret + 4;
1281                 /* Copy curve ID if supported */
1282                 for (i = 0; i < plistlen; i += 2, plist += 2)
1283                         {
1284                         if (tls_curve_allowed(s, plist, SSL_SECOP_CURVE_SUPPORTED))
1285                                 {
1286                                 *etmp++ = plist[0];
1287                                 *etmp++ = plist[1];
1288                                 }
1289                         }
1290
1291                 plistlen = etmp - ret - 4;
1292
1293                 /* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
1294                  * elliptic_curve_list, but the examples use two bytes.
1295                  * http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
1296                  * resolves this to two bytes.
1297                  */
1298                 s2n(plistlen + 2, ret);
1299                 s2n(plistlen, ret);
1300                 ret+=plistlen;
1301                 }
1302 #endif /* OPENSSL_NO_EC */
1303
1304         if (tls_use_ticket(s))
1305                 {
1306                 int ticklen;
1307                 if (!s->new_session && s->session && s->session->tlsext_tick)
1308                         ticklen = s->session->tlsext_ticklen;
1309                 else if (s->session && s->tlsext_session_ticket &&
1310                          s->tlsext_session_ticket->data)
1311                         {
1312                         ticklen = s->tlsext_session_ticket->length;
1313                         s->session->tlsext_tick = OPENSSL_malloc(ticklen);
1314                         if (!s->session->tlsext_tick)
1315                                 return NULL;
1316                         memcpy(s->session->tlsext_tick,
1317                                s->tlsext_session_ticket->data,
1318                                ticklen);
1319                         s->session->tlsext_ticklen = ticklen;
1320                         }
1321                 else
1322                         ticklen = 0;
1323                 if (ticklen == 0 && s->tlsext_session_ticket &&
1324                     s->tlsext_session_ticket->data == NULL)
1325                         goto skip_ext;
1326                 /* Check for enough room 2 for extension type, 2 for len
1327                  * rest for ticket
1328                  */
1329                 if ((long)(limit - ret - 4 - ticklen) < 0) return NULL;
1330                 s2n(TLSEXT_TYPE_session_ticket,ret); 
1331                 s2n(ticklen,ret);
1332                 if (ticklen)
1333                         {
1334                         memcpy(ret, s->session->tlsext_tick, ticklen);
1335                         ret += ticklen;
1336                         }
1337                 }
1338                 skip_ext:
1339
1340         if (SSL_USE_SIGALGS(s))
1341                 {
1342                 size_t salglen;
1343                 const unsigned char *salg;
1344                 unsigned char *etmp;
1345                 salglen = tls12_get_psigalgs(s, &salg);
1346                 if ((size_t)(limit - ret) < salglen + 6)
1347                         return NULL; 
1348                 s2n(TLSEXT_TYPE_signature_algorithms,ret);
1349                 etmp = ret;
1350                 /* Skip over lengths for now */
1351                 ret += 4;
1352                 salglen = tls12_copy_sigalgs(s, ret, salg, salglen);
1353                 /* Fill in lengths */
1354                 s2n(salglen + 2, etmp);
1355                 s2n(salglen, etmp);
1356                 ret += salglen;
1357                 }
1358
1359 #ifdef TLSEXT_TYPE_opaque_prf_input
1360         if (s->s3->client_opaque_prf_input != NULL)
1361                 {
1362                 size_t col = s->s3->client_opaque_prf_input_len;
1363                 
1364                 if ((long)(limit - ret - 6 - col) < 0)
1365                         return NULL;
1366                 if (col > 0xFFFD) /* can't happen */
1367                         return NULL;
1368
1369                 s2n(TLSEXT_TYPE_opaque_prf_input, ret); 
1370                 s2n(col + 2, ret);
1371                 s2n(col, ret);
1372                 memcpy(ret, s->s3->client_opaque_prf_input, col);
1373                 ret += col;
1374                 }
1375 #endif
1376
1377         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
1378                 {
1379                 int i;
1380                 long extlen, idlen, itmp;
1381                 OCSP_RESPID *id;
1382
1383                 idlen = 0;
1384                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1385                         {
1386                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1387                         itmp = i2d_OCSP_RESPID(id, NULL);
1388                         if (itmp <= 0)
1389                                 return NULL;
1390                         idlen += itmp + 2;
1391                         }
1392
1393                 if (s->tlsext_ocsp_exts)
1394                         {
1395                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
1396                         if (extlen < 0)
1397                                 return NULL;
1398                         }
1399                 else
1400                         extlen = 0;
1401                         
1402                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
1403                 s2n(TLSEXT_TYPE_status_request, ret);
1404                 if (extlen + idlen > 0xFFF0)
1405                         return NULL;
1406                 s2n(extlen + idlen + 5, ret);
1407                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
1408                 s2n(idlen, ret);
1409                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1410                         {
1411                         /* save position of id len */
1412                         unsigned char *q = ret;
1413                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1414                         /* skip over id len */
1415                         ret += 2;
1416                         itmp = i2d_OCSP_RESPID(id, &ret);
1417                         /* write id len */
1418                         s2n(itmp, q);
1419                         }
1420                 s2n(extlen, ret);
1421                 if (extlen > 0)
1422                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
1423                 }
1424
1425 #ifndef OPENSSL_NO_HEARTBEATS
1426         /* Add Heartbeat extension */
1427         if ((limit - ret - 4 - 1) < 0)
1428                 return NULL;
1429         s2n(TLSEXT_TYPE_heartbeat,ret);
1430         s2n(1,ret);
1431         /* Set mode:
1432          * 1: peer may send requests
1433          * 2: peer not allowed to send requests
1434          */
1435         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1436                 *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1437         else
1438                 *(ret++) = SSL_TLSEXT_HB_ENABLED;
1439 #endif
1440
1441 #ifndef OPENSSL_NO_NEXTPROTONEG
1442         if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
1443                 {
1444                 /* The client advertises an emtpy extension to indicate its
1445                  * support for Next Protocol Negotiation */
1446                 if (limit - ret - 4 < 0)
1447                         return NULL;
1448                 s2n(TLSEXT_TYPE_next_proto_neg,ret);
1449                 s2n(0,ret);
1450                 }
1451 #endif
1452
1453         if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len)
1454                 {
1455                 if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
1456                         return NULL;
1457                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1458                 s2n(2 + s->alpn_client_proto_list_len,ret);
1459                 s2n(s->alpn_client_proto_list_len,ret);
1460                 memcpy(ret, s->alpn_client_proto_list,
1461                        s->alpn_client_proto_list_len);
1462                 ret += s->alpn_client_proto_list_len;
1463                 }
1464
1465         if(SSL_get_srtp_profiles(s))
1466                 {
1467                 int el;
1468
1469                 ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
1470                 
1471                 if((limit - ret - 4 - el) < 0) return NULL;
1472
1473                 s2n(TLSEXT_TYPE_use_srtp,ret);
1474                 s2n(el,ret);
1475
1476                 if(ssl_add_clienthello_use_srtp_ext(s, ret, &el, el))
1477                         {
1478                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1479                         return NULL;
1480                         }
1481                 ret += el;
1482                 }
1483
1484         /* Add custom TLS Extensions to ClientHello */
1485         if (!custom_ext_add(s, 0, &ret, limit, al))
1486                 return NULL;
1487 #ifdef TLSEXT_TYPE_encrypt_then_mac
1488         s2n(TLSEXT_TYPE_encrypt_then_mac,ret);
1489         s2n(0,ret);
1490 #endif
1491
1492         /* Add padding to workaround bugs in F5 terminators.
1493          * See https://tools.ietf.org/html/draft-agl-tls-padding-03
1494          *
1495          * NB: because this code works out the length of all existing
1496          * extensions it MUST always appear last.
1497          */
1498         if (s->options & SSL_OP_TLSEXT_PADDING)
1499                 {
1500                 int hlen = ret - (unsigned char *)s->init_buf->data;
1501                 /* The code in s23_clnt.c to build ClientHello messages
1502                  * includes the 5-byte record header in the buffer, while
1503                  * the code in s3_clnt.c does not.
1504                  */
1505                 if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
1506                         hlen -= 5;
1507                 if (hlen > 0xff && hlen < 0x200)
1508                         {
1509                         hlen = 0x200 - hlen;
1510                         if (hlen >= 4)
1511                                 hlen -= 4;
1512                         else
1513                                 hlen = 0;
1514
1515                         s2n(TLSEXT_TYPE_padding, ret);
1516                         s2n(hlen, ret);
1517                         memset(ret, 0, hlen);
1518                         ret += hlen;
1519                         }
1520                 }
1521
1522         if ((extdatalen = ret-orig-2)== 0) 
1523                 return orig;
1524
1525         s2n(extdatalen, orig);
1526         return ret;
1527         }
1528
1529 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *buf, unsigned char *limit, int *al)
1530         {
1531         int extdatalen=0;
1532         unsigned char *orig = buf;
1533         unsigned char *ret = buf;
1534 #ifndef OPENSSL_NO_NEXTPROTONEG
1535         int next_proto_neg_seen;
1536 #endif
1537 #ifndef OPENSSL_NO_EC
1538         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1539         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1540         int using_ecc = (alg_k & (SSL_kECDHE|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA);
1541         using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
1542 #endif
1543         /* don't add extensions for SSLv3, unless doing secure renegotiation */
1544         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
1545                 return orig;
1546         
1547         ret+=2;
1548         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1549
1550         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
1551                 { 
1552                 if ((long)(limit - ret - 4) < 0) return NULL; 
1553
1554                 s2n(TLSEXT_TYPE_server_name,ret);
1555                 s2n(0,ret);
1556                 }
1557
1558         if(s->s3->send_connection_binding)
1559         {
1560           int el;
1561           
1562           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
1563               {
1564               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1565               return NULL;
1566               }
1567
1568           if((limit - ret - 4 - el) < 0) return NULL;
1569           
1570           s2n(TLSEXT_TYPE_renegotiate,ret);
1571           s2n(el,ret);
1572
1573           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
1574               {
1575               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1576               return NULL;
1577               }
1578
1579           ret += el;
1580         }
1581
1582 #ifndef OPENSSL_NO_EC
1583         if (using_ecc)
1584                 {
1585                 const unsigned char *plist;
1586                 size_t plistlen;
1587                 /* Add TLS extension ECPointFormats to the ServerHello message */
1588                 long lenmax; 
1589
1590                 tls1_get_formatlist(s, &plist, &plistlen);
1591
1592                 if ((lenmax = limit - ret - 5) < 0) return NULL; 
1593                 if (plistlen > (size_t)lenmax) return NULL;
1594                 if (plistlen > 255)
1595                         {
1596                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1597                         return NULL;
1598                         }
1599                 
1600                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1601                 s2n(plistlen + 1,ret);
1602                 *(ret++) = (unsigned char) plistlen;
1603                 memcpy(ret, plist, plistlen);
1604                 ret+=plistlen;
1605
1606                 }
1607         /* Currently the server should not respond with a SupportedCurves extension */
1608 #endif /* OPENSSL_NO_EC */
1609
1610         if (s->tlsext_ticket_expected && tls_use_ticket(s))
1611                 { 
1612                 if ((long)(limit - ret - 4) < 0) return NULL; 
1613                 s2n(TLSEXT_TYPE_session_ticket,ret);
1614                 s2n(0,ret);
1615                 }
1616
1617         if (s->tlsext_status_expected)
1618                 { 
1619                 if ((long)(limit - ret - 4) < 0) return NULL; 
1620                 s2n(TLSEXT_TYPE_status_request,ret);
1621                 s2n(0,ret);
1622                 }
1623
1624 #ifdef TLSEXT_TYPE_opaque_prf_input
1625         if (s->s3->server_opaque_prf_input != NULL)
1626                 {
1627                 size_t sol = s->s3->server_opaque_prf_input_len;
1628                 
1629                 if ((long)(limit - ret - 6 - sol) < 0)
1630                         return NULL;
1631                 if (sol > 0xFFFD) /* can't happen */
1632                         return NULL;
1633
1634                 s2n(TLSEXT_TYPE_opaque_prf_input, ret); 
1635                 s2n(sol + 2, ret);
1636                 s2n(sol, ret);
1637                 memcpy(ret, s->s3->server_opaque_prf_input, sol);
1638                 ret += sol;
1639                 }
1640 #endif
1641
1642         if(s->srtp_profile)
1643                 {
1644                 int el;
1645
1646                 ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
1647                 
1648                 if((limit - ret - 4 - el) < 0) return NULL;
1649
1650                 s2n(TLSEXT_TYPE_use_srtp,ret);
1651                 s2n(el,ret);
1652
1653                 if(ssl_add_serverhello_use_srtp_ext(s, ret, &el, el))
1654                         {
1655                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1656                         return NULL;
1657                         }
1658                 ret+=el;
1659                 }
1660
1661         if (((s->s3->tmp.new_cipher->id & 0xFFFF)==0x80 || (s->s3->tmp.new_cipher->id & 0xFFFF)==0x81) 
1662                 && (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG))
1663                 { const unsigned char cryptopro_ext[36] = {
1664                         0xfd, 0xe8, /*65000*/
1665                         0x00, 0x20, /*32 bytes length*/
1666                         0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85, 
1667                         0x03,   0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06, 
1668                         0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08, 
1669                         0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17};
1670                         if (limit-ret<36) return NULL;
1671                         memcpy(ret,cryptopro_ext,36);
1672                         ret+=36;
1673
1674                 }
1675
1676 #ifndef OPENSSL_NO_HEARTBEATS
1677         /* Add Heartbeat extension if we've received one */
1678         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED)
1679                 {
1680                 if ((limit - ret - 4 - 1) < 0)
1681                         return NULL;
1682                 s2n(TLSEXT_TYPE_heartbeat,ret);
1683                 s2n(1,ret);
1684                 /* Set mode:
1685                  * 1: peer may send requests
1686                  * 2: peer not allowed to send requests
1687                  */
1688                 if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1689                         *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1690                 else
1691                         *(ret++) = SSL_TLSEXT_HB_ENABLED;
1692
1693                 }
1694 #endif
1695
1696 #ifndef OPENSSL_NO_NEXTPROTONEG
1697         next_proto_neg_seen = s->s3->next_proto_neg_seen;
1698         s->s3->next_proto_neg_seen = 0;
1699         if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb)
1700                 {
1701                 const unsigned char *npa;
1702                 unsigned int npalen;
1703                 int r;
1704
1705                 r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg);
1706                 if (r == SSL_TLSEXT_ERR_OK)
1707                         {
1708                         if ((long)(limit - ret - 4 - npalen) < 0) return NULL;
1709                         s2n(TLSEXT_TYPE_next_proto_neg,ret);
1710                         s2n(npalen,ret);
1711                         memcpy(ret, npa, npalen);
1712                         ret += npalen;
1713                         s->s3->next_proto_neg_seen = 1;
1714                         }
1715                 }
1716 #endif
1717         if (!custom_ext_add(s, 1, &ret, limit, al))
1718                 return NULL;
1719 #ifdef TLSEXT_TYPE_encrypt_then_mac
1720         if (s->s3->flags & TLS1_FLAGS_ENCRYPT_THEN_MAC)
1721                 {
1722                 /* Don't use encrypt_then_mac if AEAD: might want
1723                  * to disable for other ciphersuites too.
1724                  */
1725                 if (s->s3->tmp.new_cipher->algorithm_mac == SSL_AEAD)
1726                         s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
1727                 else
1728                         {
1729                         s2n(TLSEXT_TYPE_encrypt_then_mac,ret);
1730                         s2n(0,ret);
1731                         }
1732                 }
1733 #endif
1734
1735         if (s->s3->alpn_selected)
1736                 {
1737                 const unsigned char *selected = s->s3->alpn_selected;
1738                 unsigned len = s->s3->alpn_selected_len;
1739
1740                 if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
1741                         return NULL;
1742                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1743                 s2n(3 + len,ret);
1744                 s2n(1 + len,ret);
1745                 *ret++ = len;
1746                 memcpy(ret, selected, len);
1747                 ret += len;
1748                 }
1749
1750         if ((extdatalen = ret-orig-2)== 0) 
1751                 return orig;
1752
1753         s2n(extdatalen, orig);
1754         return ret;
1755         }
1756
1757 /* tls1_alpn_handle_client_hello is called to process the ALPN extension in a
1758  * ClientHello.
1759  *   data: the contents of the extension, not including the type and length.
1760  *   data_len: the number of bytes in |data|
1761  *   al: a pointer to the alert value to send in the event of a non-zero
1762  *       return.
1763  *
1764  *   returns: 0 on success. */
1765 static int tls1_alpn_handle_client_hello(SSL *s, const unsigned char *data,
1766                                          unsigned data_len, int *al)
1767         {
1768         unsigned i;
1769         unsigned proto_len;
1770         const unsigned char *selected;
1771         unsigned char selected_len;
1772         int r;
1773
1774         if (s->ctx->alpn_select_cb == NULL)
1775                 return 0;
1776
1777         if (data_len < 2)
1778                 goto parse_error;
1779
1780         /* data should contain a uint16 length followed by a series of 8-bit,
1781          * length-prefixed strings. */
1782         i = ((unsigned) data[0]) << 8 |
1783             ((unsigned) data[1]);
1784         data_len -= 2;
1785         data += 2;
1786         if (data_len != i)
1787                 goto parse_error;
1788
1789         if (data_len < 2)
1790                 goto parse_error;
1791
1792         for (i = 0; i < data_len;)
1793                 {
1794                 proto_len = data[i];
1795                 i++;
1796
1797                 if (proto_len == 0)
1798                         goto parse_error;
1799
1800                 if (i + proto_len < i || i + proto_len > data_len)
1801                         goto parse_error;
1802
1803                 i += proto_len;
1804                 }
1805
1806         r = s->ctx->alpn_select_cb(s, &selected, &selected_len, data, data_len,
1807                                    s->ctx->alpn_select_cb_arg);
1808         if (r == SSL_TLSEXT_ERR_OK) {
1809                 if (s->s3->alpn_selected)
1810                         OPENSSL_free(s->s3->alpn_selected);
1811                 s->s3->alpn_selected = OPENSSL_malloc(selected_len);
1812                 if (!s->s3->alpn_selected)
1813                         {
1814                         *al = SSL_AD_INTERNAL_ERROR;
1815                         return -1;
1816                         }
1817                 memcpy(s->s3->alpn_selected, selected, selected_len);
1818                 s->s3->alpn_selected_len = selected_len;
1819         }
1820         return 0;
1821
1822 parse_error:
1823         *al = SSL_AD_DECODE_ERROR;
1824         return -1;
1825         }
1826
1827 #ifndef OPENSSL_NO_EC
1828 /* ssl_check_for_safari attempts to fingerprint Safari using OS X
1829  * SecureTransport using the TLS extension block in |d|, of length |n|.
1830  * Safari, since 10.6, sends exactly these extensions, in this order:
1831  *   SNI,
1832  *   elliptic_curves
1833  *   ec_point_formats
1834  *
1835  * We wish to fingerprint Safari because they broke ECDHE-ECDSA support in 10.8,
1836  * but they advertise support. So enabling ECDHE-ECDSA ciphers breaks them.
1837  * Sadly we cannot differentiate 10.6, 10.7 and 10.8.4 (which work), from
1838  * 10.8..10.8.3 (which don't work).
1839  */
1840 static void ssl_check_for_safari(SSL *s, const unsigned char *data, const unsigned char *d, int n) {
1841         unsigned short type, size;
1842         static const unsigned char kSafariExtensionsBlock[] = {
1843                 0x00, 0x0a,  /* elliptic_curves extension */
1844                 0x00, 0x08,  /* 8 bytes */
1845                 0x00, 0x06,  /* 6 bytes of curve ids */
1846                 0x00, 0x17,  /* P-256 */
1847                 0x00, 0x18,  /* P-384 */
1848                 0x00, 0x19,  /* P-521 */
1849
1850                 0x00, 0x0b,  /* ec_point_formats */
1851                 0x00, 0x02,  /* 2 bytes */
1852                 0x01,        /* 1 point format */
1853                 0x00,        /* uncompressed */
1854         };
1855
1856         /* The following is only present in TLS 1.2 */
1857         static const unsigned char kSafariTLS12ExtensionsBlock[] = {
1858                 0x00, 0x0d,  /* signature_algorithms */
1859                 0x00, 0x0c,  /* 12 bytes */
1860                 0x00, 0x0a,  /* 10 bytes */
1861                 0x05, 0x01,  /* SHA-384/RSA */
1862                 0x04, 0x01,  /* SHA-256/RSA */
1863                 0x02, 0x01,  /* SHA-1/RSA */
1864                 0x04, 0x03,  /* SHA-256/ECDSA */
1865                 0x02, 0x03,  /* SHA-1/ECDSA */
1866         };
1867
1868         if (data >= (d+n-2))
1869                 return;
1870         data += 2;
1871
1872         if (data > (d+n-4))
1873                 return;
1874         n2s(data,type);
1875         n2s(data,size);
1876
1877         if (type != TLSEXT_TYPE_server_name)
1878                 return;
1879
1880         if (data+size > d+n)
1881                 return;
1882         data += size;
1883
1884         if (TLS1_get_client_version(s) >= TLS1_2_VERSION)
1885                 {
1886                 const size_t len1 = sizeof(kSafariExtensionsBlock);
1887                 const size_t len2 = sizeof(kSafariTLS12ExtensionsBlock);
1888
1889                 if (data + len1 + len2 != d+n)
1890                         return;
1891                 if (memcmp(data, kSafariExtensionsBlock, len1) != 0)
1892                         return;
1893                 if (memcmp(data + len1, kSafariTLS12ExtensionsBlock, len2) != 0)
1894                         return;
1895                 }
1896         else
1897                 {
1898                 const size_t len = sizeof(kSafariExtensionsBlock);
1899
1900                 if (data + len != d+n)
1901                         return;
1902                 if (memcmp(data, kSafariExtensionsBlock, len) != 0)
1903                         return;
1904                 }
1905
1906         s->s3->is_probably_safari = 1;
1907 }
1908 #endif /* !OPENSSL_NO_EC */
1909
1910
1911 static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al) 
1912         {       
1913         unsigned short type;
1914         unsigned short size;
1915         unsigned short len;
1916         unsigned char *data = *p;
1917         int renegotiate_seen = 0;
1918         size_t i;
1919
1920         s->servername_done = 0;
1921         s->tlsext_status_type = -1;
1922 #ifndef OPENSSL_NO_NEXTPROTONEG
1923         s->s3->next_proto_neg_seen = 0;
1924 #endif
1925
1926         if (s->s3->alpn_selected)
1927                 {
1928                 OPENSSL_free(s->s3->alpn_selected);
1929                 s->s3->alpn_selected = NULL;
1930                 }
1931
1932         /* Clear observed custom extensions */
1933         s->s3->serverinfo_client_tlsext_custom_types_count = 0;
1934         if (s->s3->serverinfo_client_tlsext_custom_types != NULL)
1935                 {
1936                 OPENSSL_free(s->s3->serverinfo_client_tlsext_custom_types);
1937                 s->s3->serverinfo_client_tlsext_custom_types = NULL;
1938                 }
1939
1940 #ifndef OPENSSL_NO_HEARTBEATS
1941         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
1942                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
1943 #endif
1944
1945 #ifndef OPENSSL_NO_EC
1946         if (s->options & SSL_OP_SAFARI_ECDHE_ECDSA_BUG)
1947                 ssl_check_for_safari(s, data, d, n);
1948 #endif /* !OPENSSL_NO_EC */
1949
1950         /* Clear any signature algorithms extension received */
1951         if (s->cert->peer_sigalgs)
1952                 {
1953                 OPENSSL_free(s->cert->peer_sigalgs);
1954                 s->cert->peer_sigalgs = NULL;
1955                 }
1956         /* Clear any shared sigtnature algorithms */
1957         if (s->cert->shared_sigalgs)
1958                 {
1959                 OPENSSL_free(s->cert->shared_sigalgs);
1960                 s->cert->shared_sigalgs = NULL;
1961                 }
1962         /* Clear certificate digests and validity flags */
1963         for (i = 0; i < SSL_PKEY_NUM; i++)
1964                 {
1965                 s->cert->pkeys[i].digest = NULL;
1966                 s->cert->pkeys[i].valid_flags = 0;
1967                 }
1968
1969 #ifdef TLSEXT_TYPE_encrypt_then_mac
1970         s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
1971 #endif
1972
1973         if (data >= (d+n-2))
1974                 goto ri_check;
1975         n2s(data,len);
1976
1977         if (data > (d+n-len)) 
1978                 goto ri_check;
1979
1980         while (data <= (d+n-4))
1981                 {
1982                 n2s(data,type);
1983                 n2s(data,size);
1984
1985                 if (data+size > (d+n))
1986                         goto ri_check;
1987 #if 0
1988                 fprintf(stderr,"Received extension type %d size %d\n",type,size);
1989 #endif
1990                 if (s->tlsext_debug_cb)
1991                         s->tlsext_debug_cb(s, 0, type, data, size,
1992                                                 s->tlsext_debug_arg);
1993 /* The servername extension is treated as follows:
1994
1995    - Only the hostname type is supported with a maximum length of 255.
1996    - The servername is rejected if too long or if it contains zeros,
1997      in which case an fatal alert is generated.
1998    - The servername field is maintained together with the session cache.
1999    - When a session is resumed, the servername call back invoked in order
2000      to allow the application to position itself to the right context. 
2001    - The servername is acknowledged if it is new for a session or when 
2002      it is identical to a previously used for the same session. 
2003      Applications can control the behaviour.  They can at any time
2004      set a 'desirable' servername for a new SSL object. This can be the
2005      case for example with HTTPS when a Host: header field is received and
2006      a renegotiation is requested. In this case, a possible servername
2007      presented in the new client hello is only acknowledged if it matches
2008      the value of the Host: field. 
2009    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
2010      if they provide for changing an explicit servername context for the session,
2011      i.e. when the session has been established with a servername extension. 
2012    - On session reconnect, the servername extension may be absent. 
2013
2014 */      
2015
2016                 if (type == TLSEXT_TYPE_server_name)
2017                         {
2018                         unsigned char *sdata;
2019                         int servname_type;
2020                         int dsize; 
2021                 
2022                         if (size < 2) 
2023                                 {
2024                                 *al = SSL_AD_DECODE_ERROR;
2025                                 return 0;
2026                                 }
2027                         n2s(data,dsize);  
2028                         size -= 2;
2029                         if (dsize > size  ) 
2030                                 {
2031                                 *al = SSL_AD_DECODE_ERROR;
2032                                 return 0;
2033                                 } 
2034
2035                         sdata = data;
2036                         while (dsize > 3) 
2037                                 {
2038                                 servname_type = *(sdata++); 
2039                                 n2s(sdata,len);
2040                                 dsize -= 3;
2041
2042                                 if (len > dsize) 
2043                                         {
2044                                         *al = SSL_AD_DECODE_ERROR;
2045                                         return 0;
2046                                         }
2047                                 if (s->servername_done == 0)
2048                                 switch (servname_type)
2049                                         {
2050                                 case TLSEXT_NAMETYPE_host_name:
2051                                         if (!s->hit)
2052                                                 {
2053                                                 if(s->session->tlsext_hostname)
2054                                                         {
2055                                                         *al = SSL_AD_DECODE_ERROR;
2056                                                         return 0;
2057                                                         }
2058                                                 if (len > TLSEXT_MAXLEN_host_name)
2059                                                         {
2060                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
2061                                                         return 0;
2062                                                         }
2063                                                 if ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL)
2064                                                         {
2065                                                         *al = TLS1_AD_INTERNAL_ERROR;
2066                                                         return 0;
2067                                                         }
2068                                                 memcpy(s->session->tlsext_hostname, sdata, len);
2069                                                 s->session->tlsext_hostname[len]='\0';
2070                                                 if (strlen(s->session->tlsext_hostname) != len) {
2071                                                         OPENSSL_free(s->session->tlsext_hostname);
2072                                                         s->session->tlsext_hostname = NULL;
2073                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
2074                                                         return 0;
2075                                                 }
2076                                                 s->servername_done = 1; 
2077
2078                                                 }
2079                                         else 
2080                                                 s->servername_done = s->session->tlsext_hostname
2081                                                         && strlen(s->session->tlsext_hostname) == len 
2082                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
2083                                         
2084                                         break;
2085
2086                                 default:
2087                                         break;
2088                                         }
2089                                  
2090                                 dsize -= len;
2091                                 }
2092                         if (dsize != 0) 
2093                                 {
2094                                 *al = SSL_AD_DECODE_ERROR;
2095                                 return 0;
2096                                 }
2097
2098                         }
2099 #ifndef OPENSSL_NO_SRP
2100                 else if (type == TLSEXT_TYPE_srp)
2101                         {
2102                         if (size <= 0 || ((len = data[0])) != (size -1))
2103                                 {
2104                                 *al = SSL_AD_DECODE_ERROR;
2105                                 return 0;
2106                                 }
2107                         if (s->srp_ctx.login != NULL)
2108                                 {
2109                                 *al = SSL_AD_DECODE_ERROR;
2110                                 return 0;
2111                                 }
2112                         if ((s->srp_ctx.login = OPENSSL_malloc(len+1)) == NULL)
2113                                 return -1;
2114                         memcpy(s->srp_ctx.login, &data[1], len);
2115                         s->srp_ctx.login[len]='\0';
2116   
2117                         if (strlen(s->srp_ctx.login) != len) 
2118                                 {
2119                                 *al = SSL_AD_DECODE_ERROR;
2120                                 return 0;
2121                                 }
2122                         }
2123 #endif
2124
2125 #ifndef OPENSSL_NO_EC
2126                 else if (type == TLSEXT_TYPE_ec_point_formats)
2127                         {
2128                         unsigned char *sdata = data;
2129                         int ecpointformatlist_length = *(sdata++);
2130
2131                         if (ecpointformatlist_length != size - 1 || 
2132                                 ecpointformatlist_length < 1)
2133                                 {
2134                                 *al = TLS1_AD_DECODE_ERROR;
2135                                 return 0;
2136                                 }
2137                         if (!s->hit)
2138                                 {
2139                                 if(s->session->tlsext_ecpointformatlist)
2140                                         {
2141                                         OPENSSL_free(s->session->tlsext_ecpointformatlist);
2142                                         s->session->tlsext_ecpointformatlist = NULL;
2143                                         }
2144                                 s->session->tlsext_ecpointformatlist_length = 0;
2145                                 if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
2146                                         {
2147                                         *al = TLS1_AD_INTERNAL_ERROR;
2148                                         return 0;
2149                                         }
2150                                 s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
2151                                 memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
2152                                 }
2153 #if 0
2154                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ecpointformatlist (length=%i) ", s->session->tlsext_ecpointformatlist_length);
2155                         sdata = s->session->tlsext_ecpointformatlist;
2156                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2157                                 fprintf(stderr,"%i ",*(sdata++));
2158                         fprintf(stderr,"\n");
2159 #endif
2160                         }
2161                 else if (type == TLSEXT_TYPE_elliptic_curves)
2162                         {
2163                         unsigned char *sdata = data;
2164                         int ellipticcurvelist_length = (*(sdata++) << 8);
2165                         ellipticcurvelist_length += (*(sdata++));
2166
2167                         if (ellipticcurvelist_length != size - 2 ||
2168                                 ellipticcurvelist_length < 1)
2169                                 {
2170                                 *al = TLS1_AD_DECODE_ERROR;
2171                                 return 0;
2172                                 }
2173                         if (!s->hit)
2174                                 {
2175                                 if(s->session->tlsext_ellipticcurvelist)
2176                                         {
2177                                         *al = TLS1_AD_DECODE_ERROR;
2178                                         return 0;
2179                                         }
2180                                 s->session->tlsext_ellipticcurvelist_length = 0;
2181                                 if ((s->session->tlsext_ellipticcurvelist = OPENSSL_malloc(ellipticcurvelist_length)) == NULL)
2182                                         {
2183                                         *al = TLS1_AD_INTERNAL_ERROR;
2184                                         return 0;
2185                                         }
2186                                 s->session->tlsext_ellipticcurvelist_length = ellipticcurvelist_length;
2187                                 memcpy(s->session->tlsext_ellipticcurvelist, sdata, ellipticcurvelist_length);
2188                                 }
2189 #if 0
2190                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ellipticcurvelist (length=%i) ", s->session->tlsext_ellipticcurvelist_length);
2191                         sdata = s->session->tlsext_ellipticcurvelist;
2192                         for (i = 0; i < s->session->tlsext_ellipticcurvelist_length; i++)
2193                                 fprintf(stderr,"%i ",*(sdata++));
2194                         fprintf(stderr,"\n");
2195 #endif
2196                         }
2197 #endif /* OPENSSL_NO_EC */
2198 #ifdef TLSEXT_TYPE_opaque_prf_input
2199                 else if (type == TLSEXT_TYPE_opaque_prf_input)
2200                         {
2201                         unsigned char *sdata = data;
2202
2203                         if (size < 2)
2204                                 {
2205                                 *al = SSL_AD_DECODE_ERROR;
2206                                 return 0;
2207                                 }
2208                         n2s(sdata, s->s3->client_opaque_prf_input_len);
2209                         if (s->s3->client_opaque_prf_input_len != size - 2)
2210                                 {
2211                                 *al = SSL_AD_DECODE_ERROR;
2212                                 return 0;
2213                                 }
2214
2215                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
2216                                 OPENSSL_free(s->s3->client_opaque_prf_input);
2217                         if (s->s3->client_opaque_prf_input_len == 0)
2218                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2219                         else
2220                                 s->s3->client_opaque_prf_input = BUF_memdup(sdata, s->s3->client_opaque_prf_input_len);
2221                         if (s->s3->client_opaque_prf_input == NULL)
2222                                 {
2223                                 *al = TLS1_AD_INTERNAL_ERROR;
2224                                 return 0;
2225                                 }
2226                         }
2227 #endif
2228                 else if (type == TLSEXT_TYPE_session_ticket)
2229                         {
2230                         if (s->tls_session_ticket_ext_cb &&
2231                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
2232                                 {
2233                                 *al = TLS1_AD_INTERNAL_ERROR;
2234                                 return 0;
2235                                 }
2236                         }
2237                 else if (type == TLSEXT_TYPE_renegotiate)
2238                         {
2239                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
2240                                 return 0;
2241                         renegotiate_seen = 1;
2242                         }
2243                 else if (type == TLSEXT_TYPE_signature_algorithms)
2244                         {
2245                         int dsize;
2246                         if (s->cert->peer_sigalgs || size < 2) 
2247                                 {
2248                                 *al = SSL_AD_DECODE_ERROR;
2249                                 return 0;
2250                                 }
2251                         n2s(data,dsize);
2252                         size -= 2;
2253                         if (dsize != size || dsize & 1 || !dsize) 
2254                                 {
2255                                 *al = SSL_AD_DECODE_ERROR;
2256                                 return 0;
2257                                 }
2258                         if (!tls1_process_sigalgs(s, data, dsize))
2259                                 {
2260                                 *al = SSL_AD_DECODE_ERROR;
2261                                 return 0;
2262                                 }
2263                         /* If sigalgs received and no shared algorithms fatal
2264                          * error.
2265                          */
2266                         if (s->cert->peer_sigalgs && !s->cert->shared_sigalgs)
2267                                 {
2268                                 SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
2269                                         SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
2270                                 *al = SSL_AD_ILLEGAL_PARAMETER;
2271                                 return 0;
2272                                 }
2273                         }
2274                 else if (type == TLSEXT_TYPE_status_request)
2275                         {
2276                 
2277                         if (size < 5) 
2278                                 {
2279                                 *al = SSL_AD_DECODE_ERROR;
2280                                 return 0;
2281                                 }
2282
2283                         s->tlsext_status_type = *data++;
2284                         size--;
2285                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
2286                                 {
2287                                 const unsigned char *sdata;
2288                                 int dsize;
2289                                 /* Read in responder_id_list */
2290                                 n2s(data,dsize);
2291                                 size -= 2;
2292                                 if (dsize > size  ) 
2293                                         {
2294                                         *al = SSL_AD_DECODE_ERROR;
2295                                         return 0;
2296                                         }
2297                                 while (dsize > 0)
2298                                         {
2299                                         OCSP_RESPID *id;
2300                                         int idsize;
2301                                         if (dsize < 4)
2302                                                 {
2303                                                 *al = SSL_AD_DECODE_ERROR;
2304                                                 return 0;
2305                                                 }
2306                                         n2s(data, idsize);
2307                                         dsize -= 2 + idsize;
2308                                         size -= 2 + idsize;
2309                                         if (dsize < 0)
2310                                                 {
2311                                                 *al = SSL_AD_DECODE_ERROR;
2312                                                 return 0;
2313                                                 }
2314                                         sdata = data;
2315                                         data += idsize;
2316                                         id = d2i_OCSP_RESPID(NULL,
2317                                                                 &sdata, idsize);
2318                                         if (!id)
2319                                                 {
2320                                                 *al = SSL_AD_DECODE_ERROR;
2321                                                 return 0;
2322                                                 }
2323                                         if (data != sdata)
2324                                                 {
2325                                                 OCSP_RESPID_free(id);
2326                                                 *al = SSL_AD_DECODE_ERROR;
2327                                                 return 0;
2328                                                 }
2329                                         if (!s->tlsext_ocsp_ids
2330                                                 && !(s->tlsext_ocsp_ids =
2331                                                 sk_OCSP_RESPID_new_null()))
2332                                                 {
2333                                                 OCSP_RESPID_free(id);
2334                                                 *al = SSL_AD_INTERNAL_ERROR;
2335                                                 return 0;
2336                                                 }
2337                                         if (!sk_OCSP_RESPID_push(
2338                                                         s->tlsext_ocsp_ids, id))
2339                                                 {
2340                                                 OCSP_RESPID_free(id);
2341                                                 *al = SSL_AD_INTERNAL_ERROR;
2342                                                 return 0;
2343                                                 }
2344                                         }
2345
2346                                 /* Read in request_extensions */
2347                                 if (size < 2)
2348                                         {
2349                                         *al = SSL_AD_DECODE_ERROR;
2350                                         return 0;
2351                                         }
2352                                 n2s(data,dsize);
2353                                 size -= 2;
2354                                 if (dsize != size)
2355                                         {
2356                                         *al = SSL_AD_DECODE_ERROR;
2357                                         return 0;
2358                                         }
2359                                 sdata = data;
2360                                 if (dsize > 0)
2361                                         {
2362                                         if (s->tlsext_ocsp_exts)
2363                                                 {
2364                                                 sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
2365                                                                            X509_EXTENSION_free);
2366                                                 }
2367
2368                                         s->tlsext_ocsp_exts =
2369                                                 d2i_X509_EXTENSIONS(NULL,
2370                                                         &sdata, dsize);
2371                                         if (!s->tlsext_ocsp_exts
2372                                                 || (data + dsize != sdata))
2373                                                 {
2374                                                 *al = SSL_AD_DECODE_ERROR;
2375                                                 return 0;
2376                                                 }
2377                                         }
2378                                 }
2379                                 /* We don't know what to do with any other type
2380                                 * so ignore it.
2381                                 */
2382                                 else
2383                                         s->tlsext_status_type = -1;
2384                         }
2385 #ifndef OPENSSL_NO_HEARTBEATS
2386                 else if (type == TLSEXT_TYPE_heartbeat)
2387                         {
2388                         switch(data[0])
2389                                 {
2390                                 case 0x01:      /* Client allows us to send HB requests */
2391                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2392                                                         break;
2393                                 case 0x02:      /* Client doesn't accept HB requests */
2394                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2395                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2396                                                         break;
2397                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
2398                                                         return 0;
2399                                 }
2400                         }
2401 #endif
2402 #ifndef OPENSSL_NO_NEXTPROTONEG
2403                 else if (type == TLSEXT_TYPE_next_proto_neg &&
2404                          s->s3->tmp.finish_md_len == 0 &&
2405                          s->s3->alpn_selected == NULL)
2406                         {
2407                         /* We shouldn't accept this extension on a
2408                          * renegotiation.
2409                          *
2410                          * s->new_session will be set on renegotiation, but we
2411                          * probably shouldn't rely that it couldn't be set on
2412                          * the initial renegotation too in certain cases (when
2413                          * there's some other reason to disallow resuming an
2414                          * earlier session -- the current code won't be doing
2415                          * anything like that, but this might change).
2416
2417                          * A valid sign that there's been a previous handshake
2418                          * in this connection is if s->s3->tmp.finish_md_len >
2419                          * 0.  (We are talking about a check that will happen
2420                          * in the Hello protocol round, well before a new
2421                          * Finished message could have been computed.) */
2422                         s->s3->next_proto_neg_seen = 1;
2423                         }
2424 #endif
2425
2426                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
2427                          s->ctx->alpn_select_cb &&
2428                          s->s3->tmp.finish_md_len == 0)
2429                         {
2430                         if (tls1_alpn_handle_client_hello(s, data, size, al) != 0)
2431                                 return 0;
2432 #ifndef OPENSSL_NO_NEXTPROTONEG
2433                         /* ALPN takes precedence over NPN. */
2434                         s->s3->next_proto_neg_seen = 0;
2435 #endif
2436                         }
2437
2438                 /* session ticket processed earlier */
2439                 else if (type == TLSEXT_TYPE_use_srtp)
2440                         {
2441                         if(ssl_parse_clienthello_use_srtp_ext(s, data, size,
2442                                                               al))
2443                                 return 0;
2444                         }
2445                 /* If this ClientHello extension was unhandled and this is 
2446                  * a nonresumed connection, check whether the extension is a 
2447                  * custom TLS Extension (has a custom_srv_ext_record), and if
2448                  * so call the callback and record the extension number so that
2449                  * an appropriate ServerHello may be later returned.
2450                  */
2451                 else if (!s->hit)
2452                         {
2453                         if (!custom_ext_parse(s, 1, type, data, size, al))
2454                                 return 0;
2455                         }
2456 #ifdef TLSEXT_TYPE_encrypt_then_mac
2457                 else if (type == TLSEXT_TYPE_encrypt_then_mac)
2458                         s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
2459 #endif
2460
2461                 data+=size;
2462                 }
2463
2464         *p = data;
2465
2466         ri_check:
2467
2468         /* Need RI if renegotiating */
2469
2470         if (!renegotiate_seen && s->renegotiate &&
2471                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2472                 {
2473                 *al = SSL_AD_HANDSHAKE_FAILURE;
2474                 SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
2475                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2476                 return 0;
2477                 }
2478         /* If no signature algorithms extension set default values */
2479         if (!s->cert->peer_sigalgs)
2480                 ssl_cert_set_default_md(s->cert);
2481
2482         return 1;
2483         }
2484
2485 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n) 
2486         {
2487         int al = -1;
2488         if (ssl_scan_clienthello_tlsext(s, p, d, n, &al) <= 0) 
2489                 {
2490                 ssl3_send_alert(s,SSL3_AL_FATAL,al); 
2491                 return 0;
2492                 }
2493
2494         if (ssl_check_clienthello_tlsext_early(s) <= 0) 
2495                 {
2496                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,SSL_R_CLIENTHELLO_TLSEXT);
2497                 return 0;
2498                 }
2499         return 1;
2500 }
2501
2502 #ifndef OPENSSL_NO_NEXTPROTONEG
2503 /* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
2504  * elements of zero length are allowed and the set of elements must exactly fill
2505  * the length of the block. */
2506 static char ssl_next_proto_validate(unsigned char *d, unsigned len)
2507         {
2508         unsigned int off = 0;
2509
2510         while (off < len)
2511                 {
2512                 if (d[off] == 0)
2513                         return 0;
2514                 off += d[off];
2515                 off++;
2516                 }
2517
2518         return off == len;
2519         }
2520 #endif
2521
2522 static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
2523         {
2524         unsigned short length;
2525         unsigned short type;
2526         unsigned short size;
2527         unsigned char *data = *p;
2528         int tlsext_servername = 0;
2529         int renegotiate_seen = 0;
2530
2531 #ifndef OPENSSL_NO_NEXTPROTONEG
2532         s->s3->next_proto_neg_seen = 0;
2533 #endif
2534
2535         if (s->s3->alpn_selected)
2536                 {
2537                 OPENSSL_free(s->s3->alpn_selected);
2538                 s->s3->alpn_selected = NULL;
2539                 }
2540
2541 #ifndef OPENSSL_NO_HEARTBEATS
2542         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
2543                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
2544 #endif
2545
2546 #ifdef TLSEXT_TYPE_encrypt_then_mac
2547         s->s3->flags &= ~TLS1_FLAGS_ENCRYPT_THEN_MAC;
2548 #endif
2549
2550         if (data >= (d+n-2))
2551                 goto ri_check;
2552
2553         n2s(data,length);
2554         if (data+length != d+n)
2555                 {
2556                 *al = SSL_AD_DECODE_ERROR;
2557                 return 0;
2558                 }
2559
2560         while(data <= (d+n-4))
2561                 {
2562                 n2s(data,type);
2563                 n2s(data,size);
2564
2565                 if (data+size > (d+n))
2566                         goto ri_check;
2567
2568                 if (s->tlsext_debug_cb)
2569                         s->tlsext_debug_cb(s, 1, type, data, size,
2570                                                 s->tlsext_debug_arg);
2571
2572                 if (type == TLSEXT_TYPE_server_name)
2573                         {
2574                         if (s->tlsext_hostname == NULL || size > 0)
2575                                 {
2576                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
2577                                 return 0;
2578                                 }
2579                         tlsext_servername = 1;   
2580                         }
2581
2582 #ifndef OPENSSL_NO_EC
2583                 else if (type == TLSEXT_TYPE_ec_point_formats)
2584                         {
2585                         unsigned char *sdata = data;
2586                         int ecpointformatlist_length = *(sdata++);
2587
2588                         if (ecpointformatlist_length != size - 1)
2589                                 {
2590                                 *al = TLS1_AD_DECODE_ERROR;
2591                                 return 0;
2592                                 }
2593                         if (!s->hit)
2594                                 {
2595                                 s->session->tlsext_ecpointformatlist_length = 0;
2596                                 if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
2597                                 if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
2598                                         {
2599                                         *al = TLS1_AD_INTERNAL_ERROR;
2600                                         return 0;
2601                                         }
2602                                 s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
2603                                 memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
2604                                 }
2605 #if 0
2606                         fprintf(stderr,"ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
2607                         sdata = s->session->tlsext_ecpointformatlist;
2608                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2609                                 fprintf(stderr,"%i ",*(sdata++));
2610                         fprintf(stderr,"\n");
2611 #endif
2612                         }
2613 #endif /* OPENSSL_NO_EC */
2614
2615                 else if (type == TLSEXT_TYPE_session_ticket)
2616                         {
2617                         if (s->tls_session_ticket_ext_cb &&
2618                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
2619                                 {
2620                                 *al = TLS1_AD_INTERNAL_ERROR;
2621                                 return 0;
2622                                 }
2623                         if (!tls_use_ticket(s) || (size > 0))
2624                                 {
2625                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2626                                 return 0;
2627                                 }
2628                         s->tlsext_ticket_expected = 1;
2629                         }
2630 #ifdef TLSEXT_TYPE_opaque_prf_input
2631                 else if (type == TLSEXT_TYPE_opaque_prf_input)
2632                         {
2633                         unsigned char *sdata = data;
2634
2635                         if (size < 2)
2636                                 {
2637                                 *al = SSL_AD_DECODE_ERROR;
2638                                 return 0;
2639                                 }
2640                         n2s(sdata, s->s3->server_opaque_prf_input_len);
2641                         if (s->s3->server_opaque_prf_input_len != size - 2)
2642                                 {
2643                                 *al = SSL_AD_DECODE_ERROR;
2644                                 return 0;
2645                                 }
2646                         
2647                         if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
2648                                 OPENSSL_free(s->s3->server_opaque_prf_input);
2649                         if (s->s3->server_opaque_prf_input_len == 0)
2650                                 s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2651                         else
2652                                 s->s3->server_opaque_prf_input = BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
2653
2654                         if (s->s3->server_opaque_prf_input == NULL)
2655                                 {
2656                                 *al = TLS1_AD_INTERNAL_ERROR;
2657                                 return 0;
2658                                 }
2659                         }
2660 #endif
2661                 else if (type == TLSEXT_TYPE_status_request)
2662                         {
2663                         /* MUST be empty and only sent if we've requested
2664                          * a status request message.
2665                          */ 
2666                         if ((s->tlsext_status_type == -1) || (size > 0))
2667                                 {
2668                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2669                                 return 0;
2670                                 }
2671                         /* Set flag to expect CertificateStatus message */
2672                         s->tlsext_status_expected = 1;
2673                         }
2674 #ifndef OPENSSL_NO_NEXTPROTONEG
2675                 else if (type == TLSEXT_TYPE_next_proto_neg &&
2676                          s->s3->tmp.finish_md_len == 0)
2677                         {
2678                         unsigned char *selected;
2679                         unsigned char selected_len;
2680
2681                         /* We must have requested it. */
2682                         if (s->ctx->next_proto_select_cb == NULL)
2683                                 {
2684                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2685                                 return 0;
2686                                 }
2687                         /* The data must be valid */
2688                         if (!ssl_next_proto_validate(data, size))
2689                                 {
2690                                 *al = TLS1_AD_DECODE_ERROR;
2691                                 return 0;
2692                                 }
2693                         if (s->ctx->next_proto_select_cb(s, &selected, &selected_len, data, size, s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
2694                                 {
2695                                 *al = TLS1_AD_INTERNAL_ERROR;
2696                                 return 0;
2697                                 }
2698                         s->next_proto_negotiated = OPENSSL_malloc(selected_len);
2699                         if (!s->next_proto_negotiated)
2700                                 {
2701                                 *al = TLS1_AD_INTERNAL_ERROR;
2702                                 return 0;
2703                                 }
2704                         memcpy(s->next_proto_negotiated, selected, selected_len);
2705                         s->next_proto_negotiated_len = selected_len;
2706                         s->s3->next_proto_neg_seen = 1;
2707                         }
2708 #endif
2709
2710                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation)
2711                         {
2712                         unsigned len;
2713
2714                         /* We must have requested it. */
2715                         if (s->alpn_client_proto_list == NULL)
2716                                 {
2717                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2718                                 return 0;
2719                                 }
2720                         if (size < 4)
2721                                 {
2722                                 *al = TLS1_AD_DECODE_ERROR;
2723                                 return 0;
2724                                 }
2725                         /* The extension data consists of:
2726                          *   uint16 list_length
2727                          *   uint8 proto_length;
2728                          *   uint8 proto[proto_length]; */
2729                         len = data[0];
2730                         len <<= 8;
2731                         len |= data[1];
2732                         if (len != (unsigned) size - 2)
2733                                 {
2734                                 *al = TLS1_AD_DECODE_ERROR;
2735                                 return 0;
2736                                 }
2737                         len = data[2];
2738                         if (len != (unsigned) size - 3)
2739                                 {
2740                                 *al = TLS1_AD_DECODE_ERROR;
2741                                 return 0;
2742                                 }
2743                         if (s->s3->alpn_selected)
2744                                 OPENSSL_free(s->s3->alpn_selected);
2745                         s->s3->alpn_selected = OPENSSL_malloc(len);
2746                         if (!s->s3->alpn_selected)
2747                                 {
2748                                 *al = TLS1_AD_INTERNAL_ERROR;
2749                                 return 0;
2750                                 }
2751                         memcpy(s->s3->alpn_selected, data + 3, len);
2752                         s->s3->alpn_selected_len = len;
2753                         }
2754
2755                 else if (type == TLSEXT_TYPE_renegotiate)
2756                         {
2757                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
2758                                 return 0;
2759                         renegotiate_seen = 1;
2760                         }
2761 #ifndef OPENSSL_NO_HEARTBEATS
2762                 else if (type == TLSEXT_TYPE_heartbeat)
2763                         {
2764                         switch(data[0])
2765                                 {
2766                                 case 0x01:      /* Server allows us to send HB requests */
2767                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2768                                                         break;
2769                                 case 0x02:      /* Server doesn't accept HB requests */
2770                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2771                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2772                                                         break;
2773                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
2774                                                         return 0;
2775                                 }
2776                         }
2777 #endif
2778                 else if (type == TLSEXT_TYPE_use_srtp)
2779                         {
2780                         if(ssl_parse_serverhello_use_srtp_ext(s, data, size,
2781                                                               al))
2782                                 return 0;
2783                         }
2784                 /* If this extension type was not otherwise handled, but 
2785                  * matches a custom_cli_ext_record, then send it to the c
2786                  * callback */
2787                 else if (!custom_ext_parse(s, 0, type, data, size, al))
2788                                 return 0;
2789 #ifdef TLSEXT_TYPE_encrypt_then_mac
2790                 else if (type == TLSEXT_TYPE_encrypt_then_mac)
2791                         {
2792                         /* Ignore if inappropriate ciphersuite */
2793                         if (s->s3->tmp.new_cipher->algorithm_mac != SSL_AEAD)
2794                                 s->s3->flags |= TLS1_FLAGS_ENCRYPT_THEN_MAC;
2795                         }
2796 #endif
2797  
2798                 data += size;
2799                 }
2800
2801         if (data != d+n)
2802                 {
2803                 *al = SSL_AD_DECODE_ERROR;
2804                 return 0;
2805                 }
2806
2807         if (!s->hit && tlsext_servername == 1)
2808                 {
2809                 if (s->tlsext_hostname)
2810                         {
2811                         if (s->session->tlsext_hostname == NULL)
2812                                 {
2813                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);   
2814                                 if (!s->session->tlsext_hostname)
2815                                         {
2816                                         *al = SSL_AD_UNRECOGNIZED_NAME;
2817                                         return 0;
2818                                         }
2819                                 }
2820                         else 
2821                                 {
2822                                 *al = SSL_AD_DECODE_ERROR;
2823                                 return 0;
2824                                 }
2825                         }
2826                 }
2827
2828         *p = data;
2829
2830         ri_check:
2831
2832         /* Determine if we need to see RI. Strictly speaking if we want to
2833          * avoid an attack we should *always* see RI even on initial server
2834          * hello because the client doesn't see any renegotiation during an
2835          * attack. However this would mean we could not connect to any server
2836          * which doesn't support RI so for the immediate future tolerate RI
2837          * absence on initial connect only.
2838          */
2839         if (!renegotiate_seen
2840                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
2841                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2842                 {
2843                 *al = SSL_AD_HANDSHAKE_FAILURE;
2844                 SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT,
2845                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2846                 return 0;
2847                 }
2848
2849         return 1;
2850         }
2851
2852
2853 int ssl_prepare_clienthello_tlsext(SSL *s)
2854         {
2855
2856 #ifdef TLSEXT_TYPE_opaque_prf_input
2857         {
2858                 int r = 1;
2859         
2860                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
2861                         {
2862                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
2863                         if (!r)
2864                                 return -1;
2865                         }
2866
2867                 if (s->tlsext_opaque_prf_input != NULL)
2868                         {
2869                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
2870                                 OPENSSL_free(s->s3->client_opaque_prf_input);
2871
2872                         if (s->tlsext_opaque_prf_input_len == 0)
2873                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2874                         else
2875                                 s->s3->client_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
2876                         if (s->s3->client_opaque_prf_input == NULL)
2877                                 {
2878                                 SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
2879                                 return -1;
2880                                 }
2881                         s->s3->client_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
2882                         }
2883
2884                 if (r == 2)
2885                         /* at callback's request, insist on receiving an appropriate server opaque PRF input */
2886                         s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
2887         }
2888 #endif
2889
2890         return 1;
2891         }
2892
2893 int ssl_prepare_serverhello_tlsext(SSL *s)
2894         {
2895         return 1;
2896         }
2897
2898 static int ssl_check_clienthello_tlsext_early(SSL *s)
2899         {
2900         int ret=SSL_TLSEXT_ERR_NOACK;
2901         int al = SSL_AD_UNRECOGNIZED_NAME;
2902
2903 #ifndef OPENSSL_NO_EC
2904         /* The handling of the ECPointFormats extension is done elsewhere, namely in 
2905          * ssl3_choose_cipher in s3_lib.c.
2906          */
2907         /* The handling of the EllipticCurves extension is done elsewhere, namely in 
2908          * ssl3_choose_cipher in s3_lib.c.
2909          */
2910 #endif
2911
2912         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
2913                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
2914         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
2915                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
2916
2917 #ifdef TLSEXT_TYPE_opaque_prf_input
2918         {
2919                 /* This sort of belongs into ssl_prepare_serverhello_tlsext(),
2920                  * but we might be sending an alert in response to the client hello,
2921                  * so this has to happen here in
2922                  * ssl_check_clienthello_tlsext_early(). */
2923
2924                 int r = 1;
2925         
2926                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
2927                         {
2928                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
2929                         if (!r)
2930                                 {
2931                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2932                                 al = SSL_AD_INTERNAL_ERROR;
2933                                 goto err;
2934                                 }
2935                         }
2936
2937                 if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
2938                         OPENSSL_free(s->s3->server_opaque_prf_input);
2939                 s->s3->server_opaque_prf_input = NULL;
2940
2941                 if (s->tlsext_opaque_prf_input != NULL)
2942                         {
2943                         if (s->s3->client_opaque_prf_input != NULL &&
2944                                 s->s3->client_opaque_prf_input_len == s->tlsext_opaque_prf_input_len)
2945                                 {
2946                                 /* can only use this extension if we have a server opaque PRF input
2947                                  * of the same length as the client opaque PRF input! */
2948
2949                                 if (s->tlsext_opaque_prf_input_len == 0)
2950                                         s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2951                                 else
2952                                         s->s3->server_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
2953                                 if (s->s3->server_opaque_prf_input == NULL)
2954                                         {
2955                                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2956                                         al = SSL_AD_INTERNAL_ERROR;
2957                                         goto err;
2958                                         }
2959                                 s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
2960                                 }
2961                         }
2962
2963                 if (r == 2 && s->s3->server_opaque_prf_input == NULL)
2964                         {
2965                         /* The callback wants to enforce use of the extension,
2966                          * but we can't do that with the client opaque PRF input;
2967                          * abort the handshake.
2968                          */
2969                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
2970                         al = SSL_AD_HANDSHAKE_FAILURE;
2971                         }
2972         }
2973
2974  err:
2975 #endif
2976         switch (ret)
2977                 {
2978                 case SSL_TLSEXT_ERR_ALERT_FATAL:
2979                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
2980                         return -1;
2981
2982                 case SSL_TLSEXT_ERR_ALERT_WARNING:
2983                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
2984                         return 1; 
2985                                         
2986                 case SSL_TLSEXT_ERR_NOACK:
2987                         s->servername_done=0;
2988                         default:
2989                 return 1;
2990                 }
2991         }
2992
2993 int ssl_check_clienthello_tlsext_late(SSL *s)
2994         {
2995         int ret = SSL_TLSEXT_ERR_OK;
2996         int al;
2997
2998         /* If status request then ask callback what to do.
2999          * Note: this must be called after servername callbacks in case
3000          * the certificate has changed, and must be called after the cipher
3001          * has been chosen because this may influence which certificate is sent
3002          */
3003         if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb)
3004                 {
3005                 int r;
3006                 CERT_PKEY *certpkey;
3007                 certpkey = ssl_get_server_send_pkey(s);
3008                 /* If no certificate can't return certificate status */
3009                 if (certpkey == NULL)
3010                         {
3011                         s->tlsext_status_expected = 0;
3012                         return 1;
3013                         }
3014                 /* Set current certificate to one we will use so
3015                  * SSL_get_certificate et al can pick it up.
3016                  */
3017                 s->cert->key = certpkey;
3018                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3019                 switch (r)
3020                         {
3021                         /* We don't want to send a status request response */
3022                         case SSL_TLSEXT_ERR_NOACK:
3023                                 s->tlsext_status_expected = 0;
3024                                 break;
3025                         /* status request response should be sent */
3026                         case SSL_TLSEXT_ERR_OK:
3027                                 if (s->tlsext_ocsp_resp)
3028                                         s->tlsext_status_expected = 1;
3029                                 else
3030                                         s->tlsext_status_expected = 0;
3031                                 break;
3032                         /* something bad happened */
3033                         case SSL_TLSEXT_ERR_ALERT_FATAL:
3034                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3035                                 al = SSL_AD_INTERNAL_ERROR;
3036                                 goto err;
3037                         }
3038                 }
3039         else
3040                 s->tlsext_status_expected = 0;
3041
3042  err:
3043         switch (ret)
3044                 {
3045                 case SSL_TLSEXT_ERR_ALERT_FATAL:
3046                         ssl3_send_alert(s, SSL3_AL_FATAL, al);
3047                         return -1;
3048
3049                 case SSL_TLSEXT_ERR_ALERT_WARNING:
3050                         ssl3_send_alert(s, SSL3_AL_WARNING, al);
3051                         return 1; 
3052
3053                 default:
3054                         return 1;
3055                 }
3056         }
3057
3058 int ssl_check_serverhello_tlsext(SSL *s)
3059         {
3060         int ret=SSL_TLSEXT_ERR_NOACK;
3061         int al = SSL_AD_UNRECOGNIZED_NAME;
3062
3063 #ifndef OPENSSL_NO_EC
3064         /* If we are client and using an elliptic curve cryptography cipher
3065          * suite, then if server returns an EC point formats lists extension
3066          * it must contain uncompressed.
3067          */
3068         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3069         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3070         if ((s->tlsext_ecpointformatlist != NULL) && (s->tlsext_ecpointformatlist_length > 0) && 
3071             (s->session->tlsext_ecpointformatlist != NULL) && (s->session->tlsext_ecpointformatlist_length > 0) && 
3072             ((alg_k & (SSL_kECDHE|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA)))
3073                 {
3074                 /* we are using an ECC cipher */
3075                 size_t i;
3076                 unsigned char *list;
3077                 int found_uncompressed = 0;
3078                 list = s->session->tlsext_ecpointformatlist;
3079                 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
3080                         {
3081                         if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed)
3082                                 {
3083                                 found_uncompressed = 1;
3084                                 break;
3085                                 }
3086                         }
3087                 if (!found_uncompressed)
3088                         {
3089                         SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
3090                         return -1;
3091                         }
3092                 }
3093         ret = SSL_TLSEXT_ERR_OK;
3094 #endif /* OPENSSL_NO_EC */
3095
3096         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
3097                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
3098         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
3099                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
3100
3101 #ifdef TLSEXT_TYPE_opaque_prf_input
3102         if (s->s3->server_opaque_prf_input_len > 0)
3103                 {
3104                 /* This case may indicate that we, as a client, want to insist on using opaque PRF inputs.
3105                  * So first verify that we really have a value from the server too. */
3106
3107                 if (s->s3->server_opaque_prf_input == NULL)
3108                         {
3109                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3110                         al = SSL_AD_HANDSHAKE_FAILURE;
3111                         }
3112                 
3113                 /* Anytime the server *has* sent an opaque PRF input, we need to check
3114                  * that we have a client opaque PRF input of the same size. */
3115                 if (s->s3->client_opaque_prf_input == NULL ||
3116                     s->s3->client_opaque_prf_input_len != s->s3->server_opaque_prf_input_len)
3117                         {
3118                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3119                         al = SSL_AD_ILLEGAL_PARAMETER;
3120                         }
3121                 }
3122 #endif
3123
3124         /* If we've requested certificate status and we wont get one
3125          * tell the callback
3126          */
3127         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
3128                         && s->ctx && s->ctx->tlsext_status_cb)
3129                 {
3130                 int r;
3131                 /* Set resp to NULL, resplen to -1 so callback knows
3132                  * there is no response.
3133                  */
3134                 if (s->tlsext_ocsp_resp)
3135                         {
3136                         OPENSSL_free(s->tlsext_ocsp_resp);
3137                         s->tlsext_ocsp_resp = NULL;
3138                         }
3139                 s->tlsext_ocsp_resplen = -1;
3140                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3141                 if (r == 0)
3142                         {
3143                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
3144                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3145                         }
3146                 if (r < 0)
3147                   &nb