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[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 #include "ssl_locl.h"
119
120 const char tls1_version_str[]="TLSv1" OPENSSL_VERSION_PTEXT;
121
122 #ifndef OPENSSL_NO_TLSEXT
123 static int tls_decrypt_ticket(SSL *s, const unsigned char *tick, int ticklen,
124                                 const unsigned char *sess_id, int sesslen,
125                                 SSL_SESSION **psess);
126 static int ssl_check_clienthello_tlsext_early(SSL *s);
127 int ssl_check_serverhello_tlsext(SSL *s);
128 #endif
129
130 SSL3_ENC_METHOD TLSv1_enc_data={
131         tls1_enc,
132         tls1_mac,
133         tls1_setup_key_block,
134         tls1_generate_master_secret,
135         tls1_change_cipher_state,
136         tls1_final_finish_mac,
137         TLS1_FINISH_MAC_LENGTH,
138         tls1_cert_verify_mac,
139         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
140         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
141         tls1_alert_code,
142         tls1_export_keying_material,
143         0,
144         SSL3_HM_HEADER_LENGTH,
145         ssl3_set_handshake_header,
146         ssl3_handshake_write
147         };
148
149 SSL3_ENC_METHOD TLSv1_1_enc_data={
150         tls1_enc,
151         tls1_mac,
152         tls1_setup_key_block,
153         tls1_generate_master_secret,
154         tls1_change_cipher_state,
155         tls1_final_finish_mac,
156         TLS1_FINISH_MAC_LENGTH,
157         tls1_cert_verify_mac,
158         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
159         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
160         tls1_alert_code,
161         tls1_export_keying_material,
162         SSL_ENC_FLAG_EXPLICIT_IV,
163         SSL3_HM_HEADER_LENGTH,
164         ssl3_set_handshake_header,
165         ssl3_handshake_write
166         };
167
168 SSL3_ENC_METHOD TLSv1_2_enc_data={
169         tls1_enc,
170         tls1_mac,
171         tls1_setup_key_block,
172         tls1_generate_master_secret,
173         tls1_change_cipher_state,
174         tls1_final_finish_mac,
175         TLS1_FINISH_MAC_LENGTH,
176         tls1_cert_verify_mac,
177         TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
178         TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
179         tls1_alert_code,
180         tls1_export_keying_material,
181         SSL_ENC_FLAG_EXPLICIT_IV|SSL_ENC_FLAG_SIGALGS|SSL_ENC_FLAG_SHA256_PRF
182                 |SSL_ENC_FLAG_TLS1_2_CIPHERS,
183         SSL3_HM_HEADER_LENGTH,
184         ssl3_set_handshake_header,
185         ssl3_handshake_write
186         };
187
188 long tls1_default_timeout(void)
189         {
190         /* 2 hours, the 24 hours mentioned in the TLSv1 spec
191          * is way too long for http, the cache would over fill */
192         return(60*60*2);
193         }
194
195 int tls1_new(SSL *s)
196         {
197         if (!ssl3_new(s)) return(0);
198         s->method->ssl_clear(s);
199         return(1);
200         }
201
202 void tls1_free(SSL *s)
203         {
204 #ifndef OPENSSL_NO_TLSEXT
205         if (s->tlsext_session_ticket)
206                 {
207                 OPENSSL_free(s->tlsext_session_ticket);
208                 }
209 #endif /* OPENSSL_NO_TLSEXT */
210         ssl3_free(s);
211         }
212
213 void tls1_clear(SSL *s)
214         {
215         ssl3_clear(s);
216         s->version = s->method->version;
217         }
218
219 #ifndef OPENSSL_NO_EC
220
221 static int nid_list[] =
222         {
223                 NID_sect163k1, /* sect163k1 (1) */
224                 NID_sect163r1, /* sect163r1 (2) */
225                 NID_sect163r2, /* sect163r2 (3) */
226                 NID_sect193r1, /* sect193r1 (4) */ 
227                 NID_sect193r2, /* sect193r2 (5) */ 
228                 NID_sect233k1, /* sect233k1 (6) */
229                 NID_sect233r1, /* sect233r1 (7) */ 
230                 NID_sect239k1, /* sect239k1 (8) */ 
231                 NID_sect283k1, /* sect283k1 (9) */
232                 NID_sect283r1, /* sect283r1 (10) */ 
233                 NID_sect409k1, /* sect409k1 (11) */ 
234                 NID_sect409r1, /* sect409r1 (12) */
235                 NID_sect571k1, /* sect571k1 (13) */ 
236                 NID_sect571r1, /* sect571r1 (14) */ 
237                 NID_secp160k1, /* secp160k1 (15) */
238                 NID_secp160r1, /* secp160r1 (16) */ 
239                 NID_secp160r2, /* secp160r2 (17) */ 
240                 NID_secp192k1, /* secp192k1 (18) */
241                 NID_X9_62_prime192v1, /* secp192r1 (19) */ 
242                 NID_secp224k1, /* secp224k1 (20) */ 
243                 NID_secp224r1, /* secp224r1 (21) */
244                 NID_secp256k1, /* secp256k1 (22) */ 
245                 NID_X9_62_prime256v1, /* secp256r1 (23) */ 
246                 NID_secp384r1, /* secp384r1 (24) */
247                 NID_secp521r1  /* secp521r1 (25) */     
248         };
249
250
251 static const unsigned char ecformats_default[] = 
252         {
253         TLSEXT_ECPOINTFORMAT_uncompressed,
254         TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime,
255         TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2
256         };
257
258 static const unsigned char eccurves_default[] =
259         {
260                 0,14, /* sect571r1 (14) */ 
261                 0,13, /* sect571k1 (13) */ 
262                 0,25, /* secp521r1 (25) */      
263                 0,11, /* sect409k1 (11) */ 
264                 0,12, /* sect409r1 (12) */
265                 0,24, /* secp384r1 (24) */
266                 0,9,  /* sect283k1 (9) */
267                 0,10, /* sect283r1 (10) */ 
268                 0,22, /* secp256k1 (22) */ 
269                 0,23, /* secp256r1 (23) */ 
270                 0,8,  /* sect239k1 (8) */ 
271                 0,6,  /* sect233k1 (6) */
272                 0,7,  /* sect233r1 (7) */ 
273                 0,20, /* secp224k1 (20) */ 
274                 0,21, /* secp224r1 (21) */
275                 0,4,  /* sect193r1 (4) */ 
276                 0,5,  /* sect193r2 (5) */ 
277                 0,18, /* secp192k1 (18) */
278                 0,19, /* secp192r1 (19) */ 
279                 0,1,  /* sect163k1 (1) */
280                 0,2,  /* sect163r1 (2) */
281                 0,3,  /* sect163r2 (3) */
282                 0,15, /* secp160k1 (15) */
283                 0,16, /* secp160r1 (16) */ 
284                 0,17, /* secp160r2 (17) */ 
285         };
286
287 static const unsigned char suiteb_curves[] =
288         {
289                 0, TLSEXT_curve_P_256,
290                 0, TLSEXT_curve_P_384
291         };
292
293 int tls1_ec_curve_id2nid(int curve_id)
294         {
295         /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
296         if ((curve_id < 1) || ((unsigned int)curve_id >
297                                 sizeof(nid_list)/sizeof(nid_list[0])))
298                 return 0;
299         return nid_list[curve_id-1];
300         }
301
302 int tls1_ec_nid2curve_id(int nid)
303         {
304         /* ECC curves from draft-ietf-tls-ecc-12.txt (Oct. 17, 2005) */
305         switch (nid)
306                 {
307         case NID_sect163k1: /* sect163k1 (1) */
308                 return 1;
309         case NID_sect163r1: /* sect163r1 (2) */
310                 return 2;
311         case NID_sect163r2: /* sect163r2 (3) */
312                 return 3;
313         case NID_sect193r1: /* sect193r1 (4) */ 
314                 return 4;
315         case NID_sect193r2: /* sect193r2 (5) */ 
316                 return 5;
317         case NID_sect233k1: /* sect233k1 (6) */
318                 return 6;
319         case NID_sect233r1: /* sect233r1 (7) */ 
320                 return 7;
321         case NID_sect239k1: /* sect239k1 (8) */ 
322                 return 8;
323         case NID_sect283k1: /* sect283k1 (9) */
324                 return 9;
325         case NID_sect283r1: /* sect283r1 (10) */ 
326                 return 10;
327         case NID_sect409k1: /* sect409k1 (11) */ 
328                 return 11;
329         case NID_sect409r1: /* sect409r1 (12) */
330                 return 12;
331         case NID_sect571k1: /* sect571k1 (13) */ 
332                 return 13;
333         case NID_sect571r1: /* sect571r1 (14) */ 
334                 return 14;
335         case NID_secp160k1: /* secp160k1 (15) */
336                 return 15;
337         case NID_secp160r1: /* secp160r1 (16) */ 
338                 return 16;
339         case NID_secp160r2: /* secp160r2 (17) */ 
340                 return 17;
341         case NID_secp192k1: /* secp192k1 (18) */
342                 return 18;
343         case NID_X9_62_prime192v1: /* secp192r1 (19) */ 
344                 return 19;
345         case NID_secp224k1: /* secp224k1 (20) */ 
346                 return 20;
347         case NID_secp224r1: /* secp224r1 (21) */
348                 return 21;
349         case NID_secp256k1: /* secp256k1 (22) */ 
350                 return 22;
351         case NID_X9_62_prime256v1: /* secp256r1 (23) */ 
352                 return 23;
353         case NID_secp384r1: /* secp384r1 (24) */
354                 return 24;
355         case NID_secp521r1:  /* secp521r1 (25) */       
356                 return 25;
357         default:
358                 return 0;
359                 }
360         }
361 /* Get curves list, if "sess" is set return client curves otherwise
362  * preferred list
363  */
364 static void tls1_get_curvelist(SSL *s, int sess,
365                                         const unsigned char **pcurves,
366                                         size_t *pcurveslen)
367         {
368         if (sess)
369                 {
370                 *pcurves = s->session->tlsext_ellipticcurvelist;
371                 *pcurveslen = s->session->tlsext_ellipticcurvelist_length;
372                 return;
373                 }
374         /* For Suite B mode only include P-256, P-384 */
375         switch (tls1_suiteb(s))
376                 {
377         case SSL_CERT_FLAG_SUITEB_128_LOS:
378                 *pcurves = suiteb_curves;
379                 *pcurveslen = sizeof(suiteb_curves);
380                 break;
381
382         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
383                 *pcurves = suiteb_curves;
384                 *pcurveslen = 2;
385                 break;
386
387         case SSL_CERT_FLAG_SUITEB_192_LOS:
388                 *pcurves = suiteb_curves + 2;
389                 *pcurveslen = 2;
390                 break;
391         default:
392                 *pcurves = s->tlsext_ellipticcurvelist;
393                 *pcurveslen = s->tlsext_ellipticcurvelist_length;
394                 }
395         if (!*pcurves)
396                 {
397                 *pcurves = eccurves_default;
398                 *pcurveslen = sizeof(eccurves_default);
399                 }
400         }
401 /* Check a curve is one of our preferences */
402 int tls1_check_curve(SSL *s, const unsigned char *p, size_t len)
403         {
404         const unsigned char *curves;
405         size_t curveslen, i;
406         unsigned int suiteb_flags = tls1_suiteb(s);
407         if (len != 3 || p[0] != NAMED_CURVE_TYPE)
408                 return 0;
409         /* Check curve matches Suite B preferences */
410         if (suiteb_flags)
411                 {
412                 unsigned long cid = s->s3->tmp.new_cipher->id;
413                 if (p[1])
414                         return 0;
415                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
416                         {
417                         if (p[2] != TLSEXT_curve_P_256)
418                                 return 0;
419                         }
420                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
421                         {
422                         if (p[2] != TLSEXT_curve_P_384)
423                                 return 0;
424                         }
425                 else    /* Should never happen */
426                         return 0;
427                 }
428         tls1_get_curvelist(s, 0, &curves, &curveslen);
429         for (i = 0; i < curveslen; i += 2, curves += 2)
430                 {
431                 if (p[1] == curves[0] && p[2] == curves[1])
432                         return 1;
433                 }
434         return 0;
435         }
436
437 /* Return nth shared curve. If nmatch == -1 return number of
438  * matches. For nmatch == -2 return the NID of the curve to use for
439  * an EC tmp key.
440  */
441
442 int tls1_shared_curve(SSL *s, int nmatch)
443         {
444         const unsigned char *pref, *supp;
445         size_t preflen, supplen, i, j;
446         int k;
447         /* Can't do anything on client side */
448         if (s->server == 0)
449                 return -1;
450         if (nmatch == -2)
451                 {
452                 if (tls1_suiteb(s))
453                         {
454                         /* For Suite B ciphersuite determines curve: we 
455                          * already know these are acceptable due to previous
456                          * checks.
457                          */
458                         unsigned long cid = s->s3->tmp.new_cipher->id;
459                         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
460                                 return NID_X9_62_prime256v1; /* P-256 */
461                         if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
462                                 return NID_secp384r1; /* P-384 */
463                         /* Should never happen */
464                         return NID_undef;
465                         }
466                 /* If not Suite B just return first preference shared curve */
467                 nmatch = 0;
468                 }
469         tls1_get_curvelist(s, !!(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
470                                 &supp, &supplen);
471         tls1_get_curvelist(s, !(s->options & SSL_OP_CIPHER_SERVER_PREFERENCE),
472                                 &pref, &preflen);
473         preflen /= 2;
474         supplen /= 2;
475         k = 0;
476         for (i = 0; i < preflen; i++, pref+=2)
477                 {
478                 const unsigned char *tsupp = supp;
479                 for (j = 0; j < supplen; j++, tsupp+=2)
480                         {
481                         if (pref[0] == tsupp[0] && pref[1] == tsupp[1])
482                                 {
483                                 if (nmatch == k)
484                                         {
485                                         int id = (pref[0] << 8) | pref[1];
486                                         return tls1_ec_curve_id2nid(id);
487                                         }
488                                 k++;
489                                 }
490                         }
491                 }
492         if (nmatch == -1)
493                 return k;
494         return 0;
495         }
496
497 int tls1_set_curves(unsigned char **pext, size_t *pextlen,
498                         int *curves, size_t ncurves)
499         {
500         unsigned char *clist, *p;
501         size_t i;
502         /* Bitmap of curves included to detect duplicates: only works
503          * while curve ids < 32 
504          */
505         unsigned long dup_list = 0;
506         clist = OPENSSL_malloc(ncurves * 2);
507         if (!clist)
508                 return 0;
509         for (i = 0, p = clist; i < ncurves; i++)
510                 {
511                 unsigned long idmask;
512                 int id;
513                 id = tls1_ec_nid2curve_id(curves[i]);
514                 idmask = 1L << id;
515                 if (!id || (dup_list & idmask))
516                         {
517                         OPENSSL_free(clist);
518                         return 0;
519                         }
520                 dup_list |= idmask;
521                 s2n(id, p);
522                 }
523         if (*pext)
524                 OPENSSL_free(*pext);
525         *pext = clist;
526         *pextlen = ncurves * 2;
527         return 1;
528         }
529
530 #define MAX_CURVELIST   25
531
532 typedef struct
533         {
534         size_t nidcnt;
535         int nid_arr[MAX_CURVELIST];
536         } nid_cb_st;
537
538 static int nid_cb(const char *elem, int len, void *arg)
539         {
540         nid_cb_st *narg = arg;
541         size_t i;
542         int nid;
543         char etmp[20];
544         if (narg->nidcnt == MAX_CURVELIST)
545                 return 0;
546         if (len > (int)(sizeof(etmp) - 1))
547                 return 0;
548         memcpy(etmp, elem, len);
549         etmp[len] = 0;
550         nid = EC_curve_nist2nid(etmp);
551         if (nid == NID_undef)
552                 nid = OBJ_sn2nid(etmp);
553         if (nid == NID_undef)
554                 nid = OBJ_ln2nid(etmp);
555         if (nid == NID_undef)
556                 return 0;
557         for (i = 0; i < narg->nidcnt; i++)
558                 if (narg->nid_arr[i] == nid)
559                         return 0;
560         narg->nid_arr[narg->nidcnt++] = nid;
561         return 1;
562         }
563 /* Set curves based on a colon separate list */
564 int tls1_set_curves_list(unsigned char **pext, size_t *pextlen, 
565                                 const char *str)
566         {
567         nid_cb_st ncb;
568         ncb.nidcnt = 0;
569         if (!CONF_parse_list(str, ':', 1, nid_cb, &ncb))
570                 return 0;
571         if (pext == NULL)
572                 return 1;
573         return tls1_set_curves(pext, pextlen, ncb.nid_arr, ncb.nidcnt);
574         }
575 /* For an EC key set TLS id and required compression based on parameters */
576 static int tls1_set_ec_id(unsigned char *curve_id, unsigned char *comp_id,
577                                 EC_KEY *ec)
578         {
579         int is_prime, id;
580         const EC_GROUP *grp;
581         const EC_POINT *pt;
582         const EC_METHOD *meth;
583         if (!ec)
584                 return 0;
585         /* Determine if it is a prime field */
586         grp = EC_KEY_get0_group(ec);
587         pt = EC_KEY_get0_public_key(ec);
588         if (!grp || !pt)
589                 return 0;
590         meth = EC_GROUP_method_of(grp);
591         if (!meth)
592                 return 0;
593         if (EC_METHOD_get_field_type(meth) == NID_X9_62_prime_field)
594                 is_prime = 1;
595         else
596                 is_prime = 0;
597         /* Determine curve ID */
598         id = EC_GROUP_get_curve_name(grp);
599         id = tls1_ec_nid2curve_id(id);
600         /* If we have an ID set it, otherwise set arbitrary explicit curve */
601         if (id)
602                 {
603                 curve_id[0] = 0;
604                 curve_id[1] = (unsigned char)id;
605                 }
606         else
607                 {
608                 curve_id[0] = 0xff;
609                 if (is_prime)
610                         curve_id[1] = 0x01;
611                 else
612                         curve_id[1] = 0x02;
613                 }
614         if (comp_id)
615                 {
616                 if (EC_KEY_get_conv_form(ec) == POINT_CONVERSION_COMPRESSED)
617                         {
618                         if (is_prime)
619                                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_prime;
620                         else
621                                 *comp_id = TLSEXT_ECPOINTFORMAT_ansiX962_compressed_char2;
622                         }
623                 else
624                         *comp_id = TLSEXT_ECPOINTFORMAT_uncompressed;
625                 }
626         return 1;
627         }
628 /* Check an EC key is compatible with extensions */
629 static int tls1_check_ec_key(SSL *s,
630                         unsigned char *curve_id, unsigned char *comp_id)
631         {
632         const unsigned char *p;
633         size_t plen, i;
634         int j;
635         /* If point formats extension present check it, otherwise everything
636          * is supported (see RFC4492).
637          */
638         if (comp_id && s->session->tlsext_ecpointformatlist)
639                 {
640                 p = s->session->tlsext_ecpointformatlist;
641                 plen = s->session->tlsext_ecpointformatlist_length;
642                 for (i = 0; i < plen; i++, p++)
643                         {
644                         if (*comp_id == *p)
645                                 break;
646                         }
647                 if (i == plen)
648                         return 0;
649                 }
650         if (!curve_id)
651                 return 1;
652         /* Check curve is consistent with client and server preferences */
653         for (j = 0; j <= 1; j++)
654                 {
655                 tls1_get_curvelist(s, j, &p, &plen);
656                 for (i = 0; i < plen; i+=2, p+=2)
657                         {
658                         if (p[0] == curve_id[0] && p[1] == curve_id[1])
659                                 break;
660                         }
661                 if (i == plen)
662                         return 0;
663                 /* For clients can only check sent curve list */
664                 if (!s->server)
665                         return 1;
666                 }
667         return 1;
668         }
669
670 static void tls1_get_formatlist(SSL *s, const unsigned char **pformats,
671                                         size_t *pformatslen)
672         {
673         /* If we have a custom point format list use it otherwise
674          * use default */
675         if (s->tlsext_ecpointformatlist)
676                 {
677                 *pformats = s->tlsext_ecpointformatlist;
678                 *pformatslen = s->tlsext_ecpointformatlist_length;
679                 }
680         else
681                 {
682                 *pformats = ecformats_default;
683                 /* For Suite B we don't support char2 fields */
684                 if (tls1_suiteb(s))
685                         *pformatslen = sizeof(ecformats_default) - 1;
686                 else
687                         *pformatslen = sizeof(ecformats_default);
688                 }
689         }
690
691 /* Check cert parameters compatible with extensions: currently just checks
692  * EC certificates have compatible curves and compression.
693  */
694 static int tls1_check_cert_param(SSL *s, X509 *x, int set_ee_md)
695         {
696         unsigned char comp_id, curve_id[2];
697         EVP_PKEY *pkey;
698         int rv;
699         pkey = X509_get_pubkey(x);
700         if (!pkey)
701                 return 0;
702         /* If not EC nothing to do */
703         if (pkey->type != EVP_PKEY_EC)
704                 {
705                 EVP_PKEY_free(pkey);
706                 return 1;
707                 }
708         rv = tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec);
709         EVP_PKEY_free(pkey);
710         if (!rv)
711                 return 0;
712         /* Can't check curve_id for client certs as we don't have a
713          * supported curves extension.
714          */
715         rv = tls1_check_ec_key(s, s->server ? curve_id : NULL, &comp_id);
716         if (!rv)
717                 return 0;
718         /* Special case for suite B. We *MUST* sign using SHA256+P-256 or
719          * SHA384+P-384, adjust digest if necessary.
720          */
721         if (set_ee_md && tls1_suiteb(s))
722                 {
723                 int check_md;
724                 size_t i;
725                 CERT *c = s->cert;
726                 if (curve_id[0])
727                         return 0;
728                 /* Check to see we have necessary signing algorithm */
729                 if (curve_id[1] == TLSEXT_curve_P_256)
730                         check_md = NID_ecdsa_with_SHA256;
731                 else if (curve_id[1] == TLSEXT_curve_P_384)
732                         check_md = NID_ecdsa_with_SHA384;
733                 else
734                         return 0; /* Should never happen */
735                 for (i = 0; i < c->shared_sigalgslen; i++)
736                         if (check_md == c->shared_sigalgs[i].signandhash_nid)
737                                 break;
738                 if (i == c->shared_sigalgslen)
739                         return 0;
740                 if (set_ee_md == 2)
741                         {
742                         if (check_md == NID_ecdsa_with_SHA256)
743                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha256();
744                         else
745                                 c->pkeys[SSL_PKEY_ECC].digest = EVP_sha384();
746                         }
747                 }
748         return rv;
749         }
750 /* Check EC temporary key is compatible with client extensions */
751 int tls1_check_ec_tmp_key(SSL *s, unsigned long cid)
752         {
753         unsigned char curve_id[2];
754         EC_KEY *ec = s->cert->ecdh_tmp;
755 #ifdef OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL
756         /* Allow any curve: not just those peer supports */
757         if (s->cert->cert_flags & SSL_CERT_FLAG_BROKEN_PROTOCOL)
758                 return 1;
759 #endif
760         /* If Suite B, AES128 MUST use P-256 and AES256 MUST use P-384,
761          * no other curves permitted.
762          */
763         if (tls1_suiteb(s))
764                 {
765                 /* Curve to check determined by ciphersuite */
766                 if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)
767                         curve_id[1] = TLSEXT_curve_P_256;
768                 else if (cid == TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384)
769                         curve_id[1] = TLSEXT_curve_P_384;
770                 else
771                         return 0;
772                 curve_id[0] = 0;
773                 /* Check this curve is acceptable */
774                 if (!tls1_check_ec_key(s, curve_id, NULL))
775                         return 0;
776                 /* If auto or setting curve from callback assume OK */
777                 if (s->cert->ecdh_tmp_auto || s->cert->ecdh_tmp_cb)
778                         return 1;
779                 /* Otherwise check curve is acceptable */
780                 else 
781                         {
782                         unsigned char curve_tmp[2];
783                         if (!ec)
784                                 return 0;
785                         if (!tls1_set_ec_id(curve_tmp, NULL, ec))
786                                 return 0;
787                         if (!curve_tmp[0] || curve_tmp[1] == curve_id[1])
788                                 return 1;
789                         return 0;
790                         }
791                         
792                 }
793         if (s->cert->ecdh_tmp_auto)
794                 {
795                 /* Need a shared curve */
796                 if (tls1_shared_curve(s, 0))
797                         return 1;
798                 else return 0;
799                 }
800         if (!ec)
801                 {
802                 if (s->cert->ecdh_tmp_cb)
803                         return 1;
804                 else
805                         return 0;
806                 }
807         if (!tls1_set_ec_id(curve_id, NULL, ec))
808                 return 0;
809 /* Set this to allow use of invalid curves for testing */
810 #if 0
811         return 1;
812 #else
813         return tls1_check_ec_key(s, curve_id, NULL);
814 #endif
815         }
816
817 #endif /* OPENSSL_NO_EC */
818
819 #ifndef OPENSSL_NO_TLSEXT
820
821 /* List of supported signature algorithms and hashes. Should make this
822  * customisable at some point, for now include everything we support.
823  */
824
825 #ifdef OPENSSL_NO_RSA
826 #define tlsext_sigalg_rsa(md) /* */
827 #else
828 #define tlsext_sigalg_rsa(md) md, TLSEXT_signature_rsa,
829 #endif
830
831 #ifdef OPENSSL_NO_DSA
832 #define tlsext_sigalg_dsa(md) /* */
833 #else
834 #define tlsext_sigalg_dsa(md) md, TLSEXT_signature_dsa,
835 #endif
836
837 #ifdef OPENSSL_NO_ECDSA
838 #define tlsext_sigalg_ecdsa(md) /* */
839 #else
840 #define tlsext_sigalg_ecdsa(md) md, TLSEXT_signature_ecdsa,
841 #endif
842
843 #define tlsext_sigalg(md) \
844                 tlsext_sigalg_rsa(md) \
845                 tlsext_sigalg_dsa(md) \
846                 tlsext_sigalg_ecdsa(md)
847
848 static unsigned char tls12_sigalgs[] = {
849 #ifndef OPENSSL_NO_SHA512
850         tlsext_sigalg(TLSEXT_hash_sha512)
851         tlsext_sigalg(TLSEXT_hash_sha384)
852 #endif
853 #ifndef OPENSSL_NO_SHA256
854         tlsext_sigalg(TLSEXT_hash_sha256)
855         tlsext_sigalg(TLSEXT_hash_sha224)
856 #endif
857 #ifndef OPENSSL_NO_SHA
858         tlsext_sigalg(TLSEXT_hash_sha1)
859 #endif
860 #ifndef OPENSSL_NO_MD5
861         tlsext_sigalg_rsa(TLSEXT_hash_md5)
862 #endif
863 };
864
865 static unsigned char suiteb_sigalgs[] = {
866         tlsext_sigalg_ecdsa(TLSEXT_hash_sha256)
867         tlsext_sigalg_ecdsa(TLSEXT_hash_sha384)
868 };
869
870 size_t tls12_get_psigalgs(SSL *s, const unsigned char **psigs)
871         {
872         /* If Suite B mode use Suite B sigalgs only, ignore any other
873          * preferences.
874          */
875         switch (tls1_suiteb(s))
876                 {
877         case SSL_CERT_FLAG_SUITEB_128_LOS:
878                 *psigs = suiteb_sigalgs;
879                 return sizeof(suiteb_sigalgs);
880
881         case SSL_CERT_FLAG_SUITEB_128_LOS_ONLY:
882                 *psigs = suiteb_sigalgs;
883                 return 2;
884
885         case SSL_CERT_FLAG_SUITEB_192_LOS:
886                 *psigs = suiteb_sigalgs + 2;
887                 return 2;
888                 }
889
890         /* If server use client authentication sigalgs if not NULL */
891         if (s->server && s->cert->client_sigalgs)
892                 {
893                 *psigs = s->cert->client_sigalgs;
894                 return s->cert->client_sigalgslen;
895                 }
896         else if (s->cert->conf_sigalgs)
897                 {
898                 *psigs = s->cert->conf_sigalgs;
899                 return s->cert->conf_sigalgslen;
900                 }
901         else
902                 {
903                 *psigs = tls12_sigalgs;
904 #ifdef OPENSSL_FIPS
905                 /* If FIPS mode don't include MD5 which is last */
906                 if (FIPS_mode())
907                         return sizeof(tls12_sigalgs) - 2;
908                 else
909 #endif
910                         return sizeof(tls12_sigalgs);
911                 }
912         }
913 /* Check signature algorithm is consistent with sent supported signature
914  * algorithms and if so return relevant digest.
915  */
916 int tls12_check_peer_sigalg(const EVP_MD **pmd, SSL *s,
917                                 const unsigned char *sig, EVP_PKEY *pkey)
918         {
919         const unsigned char *sent_sigs;
920         size_t sent_sigslen, i;
921         int sigalg = tls12_get_sigid(pkey);
922         /* Should never happen */
923         if (sigalg == -1)
924                 return -1;
925         /* Check key type is consistent with signature */
926         if (sigalg != (int)sig[1])
927                 {
928                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
929                 return 0;
930                 }
931         if (pkey->type == EVP_PKEY_EC)
932                 {
933                 unsigned char curve_id[2], comp_id;
934                 /* Check compression and curve matches extensions */
935                 if (!tls1_set_ec_id(curve_id, &comp_id, pkey->pkey.ec))
936                         return 0;
937                 if (!s->server && !tls1_check_ec_key(s, curve_id, &comp_id))
938                         {
939                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_CURVE);
940                         return 0;
941                         }
942                 /* If Suite B only P-384+SHA384 or P-256+SHA-256 allowed */
943                 if (tls1_suiteb(s))
944                         {
945                         if (curve_id[0])
946                                 return 0;
947                         if (curve_id[1] == TLSEXT_curve_P_256)
948                                 {
949                                 if (sig[0] != TLSEXT_hash_sha256)
950                                         {
951                                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
952                                                 SSL_R_ILLEGAL_SUITEB_DIGEST);
953                                         return 0;
954                                         }
955                                 }
956                         else if (curve_id[1] == TLSEXT_curve_P_384)
957                                 {
958                                 if (sig[0] != TLSEXT_hash_sha384)
959                                         {
960                                         SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,
961                                                 SSL_R_ILLEGAL_SUITEB_DIGEST);
962                                         return 0;
963                                         }
964                                 }
965                         else
966                                 return 0;
967                         }
968                 }
969         else if (tls1_suiteb(s))
970                 return 0;
971
972         /* Check signature matches a type we sent */
973         sent_sigslen = tls12_get_psigalgs(s, &sent_sigs);
974         for (i = 0; i < sent_sigslen; i+=2, sent_sigs+=2)
975                 {
976                 if (sig[0] == sent_sigs[0] && sig[1] == sent_sigs[1])
977                         break;
978                 }
979         /* Allow fallback to SHA1 if not strict mode */
980         if (i == sent_sigslen && (sig[0] != TLSEXT_hash_sha1 || s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT))
981                 {
982                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_WRONG_SIGNATURE_TYPE);
983                 return 0;
984                 }
985         *pmd = tls12_get_hash(sig[0]);
986         if (*pmd == NULL)
987                 {
988                 SSLerr(SSL_F_TLS12_CHECK_PEER_SIGALG,SSL_R_UNKNOWN_DIGEST);
989                 return 0;
990                 }
991         /* Store the digest used so applications can retrieve it if they
992          * wish.
993          */
994         if (s->session && s->session->sess_cert)
995                 s->session->sess_cert->peer_key->digest = *pmd;
996         return 1;
997         }
998 /* Get a mask of disabled algorithms: an algorithm is disabled
999  * if it isn't supported or doesn't appear in supported signature
1000  * algorithms. Unlike ssl_cipher_get_disabled this applies to a specific
1001  * session and not global settings.
1002  * 
1003  */
1004 void ssl_set_client_disabled(SSL *s)
1005         {
1006         CERT *c = s->cert;
1007         const unsigned char *sigalgs;
1008         size_t i, sigalgslen;
1009         int have_rsa = 0, have_dsa = 0, have_ecdsa = 0;
1010         c->mask_a = 0;
1011         c->mask_k = 0;
1012         /* Don't allow TLS 1.2 only ciphers if we don't suppport them */
1013         if (!SSL_CLIENT_USE_TLS1_2_CIPHERS(s))
1014                 c->mask_ssl = SSL_TLSV1_2;
1015         else
1016                 c->mask_ssl = 0;
1017         /* Now go through all signature algorithms seeing if we support
1018          * any for RSA, DSA, ECDSA. Do this for all versions not just
1019          * TLS 1.2.
1020          */
1021         sigalgslen = tls12_get_psigalgs(s, &sigalgs);
1022         for (i = 0; i < sigalgslen; i += 2, sigalgs += 2)
1023                 {
1024                 switch(sigalgs[1])
1025                         {
1026 #ifndef OPENSSL_NO_RSA
1027                 case TLSEXT_signature_rsa:
1028                         have_rsa = 1;
1029                         break;
1030 #endif
1031 #ifndef OPENSSL_NO_DSA
1032                 case TLSEXT_signature_dsa:
1033                         have_dsa = 1;
1034                         break;
1035 #endif
1036 #ifndef OPENSSL_NO_ECDSA
1037                 case TLSEXT_signature_ecdsa:
1038                         have_ecdsa = 1;
1039                         break;
1040 #endif
1041                         }
1042                 }
1043         /* Disable auth and static DH if we don't include any appropriate
1044          * signature algorithms.
1045          */
1046         if (!have_rsa)
1047                 {
1048                 c->mask_a |= SSL_aRSA;
1049                 c->mask_k |= SSL_kDHr|SSL_kECDHr;
1050                 }
1051         if (!have_dsa)
1052                 {
1053                 c->mask_a |= SSL_aDSS;
1054                 c->mask_k |= SSL_kDHd;
1055                 }
1056         if (!have_ecdsa)
1057                 {
1058                 c->mask_a |= SSL_aECDSA;
1059                 c->mask_k |= SSL_kECDHe;
1060                 }
1061 #ifndef OPENSSL_NO_KRB5
1062         if (!kssl_tgt_is_available(s->kssl_ctx))
1063                 {
1064                 c->mask_a |= SSL_aKRB5;
1065                 c->mask_k |= SSL_kKRB5;
1066                 }
1067 #endif
1068 #ifndef OPENSSL_NO_PSK
1069         /* with PSK there must be client callback set */
1070         if (!s->psk_client_callback)
1071                 {
1072                 c->mask_a |= SSL_aPSK;
1073                 c->mask_k |= SSL_kPSK;
1074                 }
1075 #endif /* OPENSSL_NO_PSK */
1076         c->valid = 1;
1077         }
1078
1079 /* byte_compare is a compare function for qsort(3) that compares bytes. */
1080 static int byte_compare(const void *in_a, const void *in_b)
1081         {
1082         unsigned char a = *((const unsigned char*) in_a);
1083         unsigned char b = *((const unsigned char*) in_b);
1084
1085         if (a > b)
1086                 return 1;
1087         else if (a < b)
1088                 return -1;
1089         return 0;
1090 }
1091
1092 unsigned char *ssl_add_clienthello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
1093         {
1094         int extdatalen=0;
1095         unsigned char *ret = p;
1096 #ifndef OPENSSL_NO_EC
1097         /* See if we support any ECC ciphersuites */
1098         int using_ecc = 0;
1099         if (s->version >= TLS1_VERSION || SSL_IS_DTLS(s))
1100                 {
1101                 int i;
1102                 unsigned long alg_k, alg_a;
1103                 STACK_OF(SSL_CIPHER) *cipher_stack = SSL_get_ciphers(s);
1104
1105                 for (i = 0; i < sk_SSL_CIPHER_num(cipher_stack); i++)
1106                         {
1107                         SSL_CIPHER *c = sk_SSL_CIPHER_value(cipher_stack, i);
1108
1109                         alg_k = c->algorithm_mkey;
1110                         alg_a = c->algorithm_auth;
1111                         if ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)
1112                                 || (alg_a & SSL_aECDSA)))
1113                                 {
1114                                 using_ecc = 1;
1115                                 break;
1116                                 }
1117                         }
1118                 }
1119 #endif
1120
1121         /* don't add extensions for SSLv3 unless doing secure renegotiation */
1122         if (s->client_version == SSL3_VERSION
1123                                         && !s->s3->send_connection_binding)
1124                 return p;
1125
1126         ret+=2;
1127
1128         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1129
1130         if (s->tlsext_hostname != NULL)
1131                 { 
1132                 /* Add TLS extension servername to the Client Hello message */
1133                 unsigned long size_str;
1134                 long lenmax; 
1135
1136                 /* check for enough space.
1137                    4 for the servername type and entension length
1138                    2 for servernamelist length
1139                    1 for the hostname type
1140                    2 for hostname length
1141                    + hostname length 
1142                 */
1143                    
1144                 if ((lenmax = limit - ret - 9) < 0 
1145                     || (size_str = strlen(s->tlsext_hostname)) > (unsigned long)lenmax) 
1146                         return NULL;
1147                         
1148                 /* extension type and length */
1149                 s2n(TLSEXT_TYPE_server_name,ret); 
1150                 s2n(size_str+5,ret);
1151                 
1152                 /* length of servername list */
1153                 s2n(size_str+3,ret);
1154         
1155                 /* hostname type, length and hostname */
1156                 *(ret++) = (unsigned char) TLSEXT_NAMETYPE_host_name;
1157                 s2n(size_str,ret);
1158                 memcpy(ret, s->tlsext_hostname, size_str);
1159                 ret+=size_str;
1160                 }
1161
1162         /* Add RI if renegotiating */
1163         if (s->renegotiate)
1164           {
1165           int el;
1166           
1167           if(!ssl_add_clienthello_renegotiate_ext(s, 0, &el, 0))
1168               {
1169               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1170               return NULL;
1171               }
1172
1173           if((limit - p - 4 - el) < 0) return NULL;
1174           
1175           s2n(TLSEXT_TYPE_renegotiate,ret);
1176           s2n(el,ret);
1177
1178           if(!ssl_add_clienthello_renegotiate_ext(s, ret, &el, el))
1179               {
1180               SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1181               return NULL;
1182               }
1183
1184           ret += el;
1185         }
1186
1187 #ifndef OPENSSL_NO_SRP
1188         /* Add SRP username if there is one */
1189         if (s->srp_ctx.login != NULL)
1190                 { /* Add TLS extension SRP username to the Client Hello message */
1191
1192                 int login_len = strlen(s->srp_ctx.login);       
1193                 if (login_len > 255 || login_len == 0)
1194                         {
1195                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1196                         return NULL;
1197                         } 
1198
1199                 /* check for enough space.
1200                    4 for the srp type type and entension length
1201                    1 for the srp user identity
1202                    + srp user identity length 
1203                 */
1204                 if ((limit - ret - 5 - login_len) < 0) return NULL; 
1205
1206                 /* fill in the extension */
1207                 s2n(TLSEXT_TYPE_srp,ret);
1208                 s2n(login_len+1,ret);
1209                 (*ret++) = (unsigned char) login_len;
1210                 memcpy(ret, s->srp_ctx.login, login_len);
1211                 ret+=login_len;
1212                 }
1213 #endif
1214
1215 #ifndef OPENSSL_NO_EC
1216         if (using_ecc)
1217                 {
1218                 /* Add TLS extension ECPointFormats to the ClientHello message */
1219                 long lenmax; 
1220                 const unsigned char *plist;
1221                 size_t plistlen;
1222
1223                 tls1_get_formatlist(s, &plist, &plistlen);
1224
1225                 if ((lenmax = limit - ret - 5) < 0) return NULL; 
1226                 if (plistlen > (size_t)lenmax) return NULL;
1227                 if (plistlen > 255)
1228                         {
1229                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1230                         return NULL;
1231                         }
1232                 
1233                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1234                 s2n(plistlen + 1,ret);
1235                 *(ret++) = (unsigned char)plistlen ;
1236                 memcpy(ret, plist, plistlen);
1237                 ret+=plistlen;
1238
1239                 /* Add TLS extension EllipticCurves to the ClientHello message */
1240                 plist = s->tlsext_ellipticcurvelist;
1241                 tls1_get_curvelist(s, 0, &plist, &plistlen);
1242
1243                 if ((lenmax = limit - ret - 6) < 0) return NULL; 
1244                 if (plistlen > (size_t)lenmax) return NULL;
1245                 if (plistlen > 65532)
1246                         {
1247                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1248                         return NULL;
1249                         }
1250                 
1251                 s2n(TLSEXT_TYPE_elliptic_curves,ret);
1252                 s2n(plistlen + 2, ret);
1253
1254                 /* NB: draft-ietf-tls-ecc-12.txt uses a one-byte prefix for
1255                  * elliptic_curve_list, but the examples use two bytes.
1256                  * http://www1.ietf.org/mail-archive/web/tls/current/msg00538.html
1257                  * resolves this to two bytes.
1258                  */
1259                 s2n(plistlen, ret);
1260                 memcpy(ret, plist, plistlen);
1261                 ret+=plistlen;
1262                 }
1263 #endif /* OPENSSL_NO_EC */
1264
1265         if (!(SSL_get_options(s) & SSL_OP_NO_TICKET))
1266                 {
1267                 int ticklen;
1268                 if (!s->new_session && s->session && s->session->tlsext_tick)
1269                         ticklen = s->session->tlsext_ticklen;
1270                 else if (s->session && s->tlsext_session_ticket &&
1271                          s->tlsext_session_ticket->data)
1272                         {
1273                         ticklen = s->tlsext_session_ticket->length;
1274                         s->session->tlsext_tick = OPENSSL_malloc(ticklen);
1275                         if (!s->session->tlsext_tick)
1276                                 return NULL;
1277                         memcpy(s->session->tlsext_tick,
1278                                s->tlsext_session_ticket->data,
1279                                ticklen);
1280                         s->session->tlsext_ticklen = ticklen;
1281                         }
1282                 else
1283                         ticklen = 0;
1284                 if (ticklen == 0 && s->tlsext_session_ticket &&
1285                     s->tlsext_session_ticket->data == NULL)
1286                         goto skip_ext;
1287                 /* Check for enough room 2 for extension type, 2 for len
1288                  * rest for ticket
1289                  */
1290                 if ((long)(limit - ret - 4 - ticklen) < 0) return NULL;
1291                 s2n(TLSEXT_TYPE_session_ticket,ret); 
1292                 s2n(ticklen,ret);
1293                 if (ticklen)
1294                         {
1295                         memcpy(ret, s->session->tlsext_tick, ticklen);
1296                         ret += ticklen;
1297                         }
1298                 }
1299                 skip_ext:
1300
1301         if (SSL_USE_SIGALGS(s))
1302                 {
1303                 size_t salglen;
1304                 const unsigned char *salg;
1305                 salglen = tls12_get_psigalgs(s, &salg);
1306                 if ((size_t)(limit - ret) < salglen + 6)
1307                         return NULL; 
1308                 s2n(TLSEXT_TYPE_signature_algorithms,ret);
1309                 s2n(salglen + 2, ret);
1310                 s2n(salglen, ret);
1311                 memcpy(ret, salg, salglen);
1312                 ret += salglen;
1313                 }
1314
1315 #ifdef TLSEXT_TYPE_opaque_prf_input
1316         if (s->s3->client_opaque_prf_input != NULL)
1317                 {
1318                 size_t col = s->s3->client_opaque_prf_input_len;
1319                 
1320                 if ((long)(limit - ret - 6 - col < 0))
1321                         return NULL;
1322                 if (col > 0xFFFD) /* can't happen */
1323                         return NULL;
1324
1325                 s2n(TLSEXT_TYPE_opaque_prf_input, ret); 
1326                 s2n(col + 2, ret);
1327                 s2n(col, ret);
1328                 memcpy(ret, s->s3->client_opaque_prf_input, col);
1329                 ret += col;
1330                 }
1331 #endif
1332
1333         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
1334                 {
1335                 int i;
1336                 long extlen, idlen, itmp;
1337                 OCSP_RESPID *id;
1338
1339                 idlen = 0;
1340                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1341                         {
1342                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1343                         itmp = i2d_OCSP_RESPID(id, NULL);
1344                         if (itmp <= 0)
1345                                 return NULL;
1346                         idlen += itmp + 2;
1347                         }
1348
1349                 if (s->tlsext_ocsp_exts)
1350                         {
1351                         extlen = i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, NULL);
1352                         if (extlen < 0)
1353                                 return NULL;
1354                         }
1355                 else
1356                         extlen = 0;
1357                         
1358                 if ((long)(limit - ret - 7 - extlen - idlen) < 0) return NULL;
1359                 s2n(TLSEXT_TYPE_status_request, ret);
1360                 if (extlen + idlen > 0xFFF0)
1361                         return NULL;
1362                 s2n(extlen + idlen + 5, ret);
1363                 *(ret++) = TLSEXT_STATUSTYPE_ocsp;
1364                 s2n(idlen, ret);
1365                 for (i = 0; i < sk_OCSP_RESPID_num(s->tlsext_ocsp_ids); i++)
1366                         {
1367                         /* save position of id len */
1368                         unsigned char *q = ret;
1369                         id = sk_OCSP_RESPID_value(s->tlsext_ocsp_ids, i);
1370                         /* skip over id len */
1371                         ret += 2;
1372                         itmp = i2d_OCSP_RESPID(id, &ret);
1373                         /* write id len */
1374                         s2n(itmp, q);
1375                         }
1376                 s2n(extlen, ret);
1377                 if (extlen > 0)
1378                         i2d_X509_EXTENSIONS(s->tlsext_ocsp_exts, &ret);
1379                 }
1380
1381 #ifndef OPENSSL_NO_HEARTBEATS
1382         /* Add Heartbeat extension */
1383         s2n(TLSEXT_TYPE_heartbeat,ret);
1384         s2n(1,ret);
1385         /* Set mode:
1386          * 1: peer may send requests
1387          * 2: peer not allowed to send requests
1388          */
1389         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1390                 *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1391         else
1392                 *(ret++) = SSL_TLSEXT_HB_ENABLED;
1393 #endif
1394
1395 #ifndef OPENSSL_NO_NEXTPROTONEG
1396         if (s->ctx->next_proto_select_cb && !s->s3->tmp.finish_md_len)
1397                 {
1398                 /* The client advertises an emtpy extension to indicate its
1399                  * support for Next Protocol Negotiation */
1400                 if (limit - ret - 4 < 0)
1401                         return NULL;
1402                 s2n(TLSEXT_TYPE_next_proto_neg,ret);
1403                 s2n(0,ret);
1404                 }
1405 #endif
1406
1407         if (s->alpn_client_proto_list && !s->s3->tmp.finish_md_len)
1408                 {
1409                 if ((size_t)(limit - ret) < 6 + s->alpn_client_proto_list_len)
1410                         return NULL;
1411                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1412                 s2n(2 + s->alpn_client_proto_list_len,ret);
1413                 s2n(s->alpn_client_proto_list_len,ret);
1414                 memcpy(ret, s->alpn_client_proto_list,
1415                        s->alpn_client_proto_list_len);
1416                 ret += s->alpn_client_proto_list_len;
1417                 }
1418
1419         if(SSL_get_srtp_profiles(s))
1420                 {
1421                 int el;
1422
1423                 ssl_add_clienthello_use_srtp_ext(s, 0, &el, 0);
1424                 
1425                 if((limit - p - 4 - el) < 0) return NULL;
1426
1427                 s2n(TLSEXT_TYPE_use_srtp,ret);
1428                 s2n(el,ret);
1429
1430                 if(ssl_add_clienthello_use_srtp_ext(s, ret, &el, el))
1431                         {
1432                         SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1433                         return NULL;
1434                         }
1435                 ret += el;
1436                 }
1437
1438         /* Add TLS extension Server_Authz_DataFormats to the ClientHello */
1439         /* 2 bytes for extension type */
1440         /* 2 bytes for extension length */
1441         /* 1 byte for the list length */
1442         /* 1 byte for the list (we only support audit proofs) */
1443         if (s->ctx->tlsext_authz_server_audit_proof_cb != NULL)
1444                 {
1445                 const unsigned short ext_len = 2;
1446                 const unsigned char list_len = 1;
1447
1448                 if (limit < ret + 6)
1449                         return NULL;
1450
1451                 s2n(TLSEXT_TYPE_server_authz, ret);
1452                 /* Extension length: 2 bytes */
1453                 s2n(ext_len, ret);
1454                 *(ret++) = list_len;
1455                 *(ret++) = TLSEXT_AUTHZDATAFORMAT_audit_proof;
1456                 }
1457
1458         /* Add custom TLS Extensions to ClientHello */
1459         if (s->ctx->custom_cli_ext_records_count)
1460                 {
1461                 size_t i;
1462                 custom_cli_ext_record* record;
1463
1464                 for (i = 0; i < s->ctx->custom_cli_ext_records_count; i++)
1465                         {
1466                         const unsigned char* out = NULL;
1467                         unsigned short outlen = 0;
1468
1469                         record = &s->ctx->custom_cli_ext_records[i];
1470                         /* NULL callback sends empty extension */ 
1471                         /* -1 from callback omits extension */
1472                         if (record->fn1)
1473                                 {
1474                                 int cb_retval = 0;
1475                                 cb_retval = record->fn1(s, record->ext_type,
1476                                                         &out, &outlen,
1477                                                         record->arg);
1478                                 if (cb_retval == 0)
1479                                         return NULL; /* error */
1480                                 if (cb_retval == -1)
1481                                         continue; /* skip this extension */
1482                                 }
1483                         if (limit < ret + 4 + outlen)
1484                                 return NULL;
1485                         s2n(record->ext_type, ret);
1486                         s2n(outlen, ret);
1487                         memcpy(ret, out, outlen);
1488                         ret += outlen;
1489                         }
1490                 }
1491
1492         if ((extdatalen = ret-p-2) == 0)
1493                 return p;
1494
1495         s2n(extdatalen,p);
1496         return ret;
1497         }
1498
1499 unsigned char *ssl_add_serverhello_tlsext(SSL *s, unsigned char *p, unsigned char *limit)
1500         {
1501         int extdatalen=0;
1502         unsigned char *ret = p;
1503 #ifndef OPENSSL_NO_NEXTPROTONEG
1504         int next_proto_neg_seen;
1505 #endif
1506         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
1507         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
1508         int using_ecc = (alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA);
1509         using_ecc = using_ecc && (s->session->tlsext_ecpointformatlist != NULL);
1510
1511         /* don't add extensions for SSLv3, unless doing secure renegotiation */
1512         if (s->version == SSL3_VERSION && !s->s3->send_connection_binding)
1513                 return p;
1514         
1515         ret+=2;
1516         if (ret>=limit) return NULL; /* this really never occurs, but ... */
1517
1518         if (!s->hit && s->servername_done == 1 && s->session->tlsext_hostname != NULL)
1519                 { 
1520                 if ((long)(limit - ret - 4) < 0) return NULL; 
1521
1522                 s2n(TLSEXT_TYPE_server_name,ret);
1523                 s2n(0,ret);
1524                 }
1525
1526         if(s->s3->send_connection_binding)
1527         {
1528           int el;
1529           
1530           if(!ssl_add_serverhello_renegotiate_ext(s, 0, &el, 0))
1531               {
1532               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1533               return NULL;
1534               }
1535
1536           if((limit - p - 4 - el) < 0) return NULL;
1537           
1538           s2n(TLSEXT_TYPE_renegotiate,ret);
1539           s2n(el,ret);
1540
1541           if(!ssl_add_serverhello_renegotiate_ext(s, ret, &el, el))
1542               {
1543               SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1544               return NULL;
1545               }
1546
1547           ret += el;
1548         }
1549
1550 #ifndef OPENSSL_NO_EC
1551         if (using_ecc)
1552                 {
1553                 const unsigned char *plist;
1554                 size_t plistlen;
1555                 /* Add TLS extension ECPointFormats to the ServerHello message */
1556                 long lenmax; 
1557
1558                 tls1_get_formatlist(s, &plist, &plistlen);
1559
1560                 if ((lenmax = limit - ret - 5) < 0) return NULL; 
1561                 if (plistlen > (size_t)lenmax) return NULL;
1562                 if (plistlen > 255)
1563                         {
1564                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1565                         return NULL;
1566                         }
1567                 
1568                 s2n(TLSEXT_TYPE_ec_point_formats,ret);
1569                 s2n(plistlen + 1,ret);
1570                 *(ret++) = (unsigned char) plistlen;
1571                 memcpy(ret, plist, plistlen);
1572                 ret+=plistlen;
1573
1574                 }
1575         /* Currently the server should not respond with a SupportedCurves extension */
1576 #endif /* OPENSSL_NO_EC */
1577
1578         if (s->tlsext_ticket_expected
1579                 && !(SSL_get_options(s) & SSL_OP_NO_TICKET)) 
1580                 { 
1581                 if ((long)(limit - ret - 4) < 0) return NULL; 
1582                 s2n(TLSEXT_TYPE_session_ticket,ret);
1583                 s2n(0,ret);
1584                 }
1585
1586         if (s->tlsext_status_expected)
1587                 { 
1588                 if ((long)(limit - ret - 4) < 0) return NULL; 
1589                 s2n(TLSEXT_TYPE_status_request,ret);
1590                 s2n(0,ret);
1591                 }
1592
1593 #ifdef TLSEXT_TYPE_opaque_prf_input
1594         if (s->s3->server_opaque_prf_input != NULL)
1595                 {
1596                 size_t sol = s->s3->server_opaque_prf_input_len;
1597                 
1598                 if ((long)(limit - ret - 6 - sol) < 0)
1599                         return NULL;
1600                 if (sol > 0xFFFD) /* can't happen */
1601                         return NULL;
1602
1603                 s2n(TLSEXT_TYPE_opaque_prf_input, ret); 
1604                 s2n(sol + 2, ret);
1605                 s2n(sol, ret);
1606                 memcpy(ret, s->s3->server_opaque_prf_input, sol);
1607                 ret += sol;
1608                 }
1609 #endif
1610
1611         if(s->srtp_profile)
1612                 {
1613                 int el;
1614
1615                 ssl_add_serverhello_use_srtp_ext(s, 0, &el, 0);
1616                 
1617                 if((limit - p - 4 - el) < 0) return NULL;
1618
1619                 s2n(TLSEXT_TYPE_use_srtp,ret);
1620                 s2n(el,ret);
1621
1622                 if(ssl_add_serverhello_use_srtp_ext(s, ret, &el, el))
1623                         {
1624                         SSLerr(SSL_F_SSL_ADD_SERVERHELLO_TLSEXT, ERR_R_INTERNAL_ERROR);
1625                         return NULL;
1626                         }
1627                 ret+=el;
1628                 }
1629
1630         if (((s->s3->tmp.new_cipher->id & 0xFFFF)==0x80 || (s->s3->tmp.new_cipher->id & 0xFFFF)==0x81) 
1631                 && (SSL_get_options(s) & SSL_OP_CRYPTOPRO_TLSEXT_BUG))
1632                 { const unsigned char cryptopro_ext[36] = {
1633                         0xfd, 0xe8, /*65000*/
1634                         0x00, 0x20, /*32 bytes length*/
1635                         0x30, 0x1e, 0x30, 0x08, 0x06, 0x06, 0x2a, 0x85, 
1636                         0x03,   0x02, 0x02, 0x09, 0x30, 0x08, 0x06, 0x06, 
1637                         0x2a, 0x85, 0x03, 0x02, 0x02, 0x16, 0x30, 0x08, 
1638                         0x06, 0x06, 0x2a, 0x85, 0x03, 0x02, 0x02, 0x17};
1639                         if (limit-ret<36) return NULL;
1640                         memcpy(ret,cryptopro_ext,36);
1641                         ret+=36;
1642
1643                 }
1644
1645 #ifndef OPENSSL_NO_HEARTBEATS
1646         /* Add Heartbeat extension if we've received one */
1647         if (s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED)
1648                 {
1649                 s2n(TLSEXT_TYPE_heartbeat,ret);
1650                 s2n(1,ret);
1651                 /* Set mode:
1652                  * 1: peer may send requests
1653                  * 2: peer not allowed to send requests
1654                  */
1655                 if (s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_RECV_REQUESTS)
1656                         *(ret++) = SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
1657                 else
1658                         *(ret++) = SSL_TLSEXT_HB_ENABLED;
1659
1660                 }
1661 #endif
1662
1663 #ifndef OPENSSL_NO_NEXTPROTONEG
1664         next_proto_neg_seen = s->s3->next_proto_neg_seen;
1665         s->s3->next_proto_neg_seen = 0;
1666         if (next_proto_neg_seen && s->ctx->next_protos_advertised_cb)
1667                 {
1668                 const unsigned char *npa;
1669                 unsigned int npalen;
1670                 int r;
1671
1672                 r = s->ctx->next_protos_advertised_cb(s, &npa, &npalen, s->ctx->next_protos_advertised_cb_arg);
1673                 if (r == SSL_TLSEXT_ERR_OK)
1674                         {
1675                         if ((long)(limit - ret - 4 - npalen) < 0) return NULL;
1676                         s2n(TLSEXT_TYPE_next_proto_neg,ret);
1677                         s2n(npalen,ret);
1678                         memcpy(ret, npa, npalen);
1679                         ret += npalen;
1680                         s->s3->next_proto_neg_seen = 1;
1681                         }
1682                 }
1683 #endif
1684
1685         /* If the client supports authz then see whether we have any to offer
1686          * to it. */
1687         if (s->s3->tlsext_authz_client_types_len)
1688                 {
1689                 size_t authz_length;
1690                 /* By now we already know the new cipher, so we can look ahead
1691                  * to see whether the cert we are going to send
1692                  * has any authz data attached to it. */
1693                 const unsigned char* authz = ssl_get_authz_data(s, &authz_length);
1694                 const unsigned char* const orig_authz = authz;
1695                 size_t i;
1696                 unsigned authz_count = 0;
1697
1698                 /* The authz data contains a number of the following structures:
1699                  *      uint8_t authz_type
1700                  *      uint16_t length
1701                  *      uint8_t data[length]
1702                  *
1703                  * First we walk over it to find the number of authz elements. */
1704                 for (i = 0; i < authz_length; i++)
1705                         {
1706                         unsigned short length;
1707                         unsigned char type;
1708
1709                         type = *(authz++);
1710                         if (memchr(s->s3->tlsext_authz_client_types,
1711                                    type,
1712                                    s->s3->tlsext_authz_client_types_len) != NULL)
1713                                 authz_count++;
1714
1715                         n2s(authz, length);
1716                         /* n2s increments authz by 2 */
1717                         i += 2;
1718                         authz += length;
1719                         i += length;
1720                         }
1721
1722                 if (authz_count)
1723                         {
1724                         /* Add TLS extension server_authz to the ServerHello message
1725                          * 2 bytes for extension type
1726                          * 2 bytes for extension length
1727                          * 1 byte for the list length
1728                          * n bytes for the list */
1729                         const unsigned short ext_len = 1 + authz_count;
1730
1731                         if ((long)(limit - ret - 4 - ext_len) < 0) return NULL;
1732                         s2n(TLSEXT_TYPE_server_authz, ret);
1733                         s2n(ext_len, ret);
1734                         *(ret++) = authz_count;
1735                         s->s3->tlsext_authz_promised_to_client = 1;
1736                         }
1737
1738                 authz = orig_authz;
1739                 for (i = 0; i < authz_length; i++)
1740                         {
1741                         unsigned short length;
1742                         unsigned char type;
1743
1744                         authz_count++;
1745                         type = *(authz++);
1746                         if (memchr(s->s3->tlsext_authz_client_types,
1747                                    type,
1748                                    s->s3->tlsext_authz_client_types_len) != NULL)
1749                                 *(ret++) = type;
1750                         n2s(authz, length);
1751                         /* n2s increments authz by 2 */
1752                         i += 2;
1753                         authz += length;
1754                         i += length;
1755                         }
1756                 }
1757
1758         /* If custom types were sent in ClientHello, add ServerHello responses */
1759         if (s->s3->tlsext_custom_types_count)
1760                 {
1761                 size_t i;
1762
1763                 for (i = 0; i < s->s3->tlsext_custom_types_count; i++)
1764                         {
1765                         size_t j;
1766                         custom_srv_ext_record *record;
1767
1768                         for (j = 0; j < s->ctx->custom_srv_ext_records_count; j++)
1769                                 {
1770                                 record = &s->ctx->custom_srv_ext_records[j];
1771                                 if (s->s3->tlsext_custom_types[i] == record->ext_type)
1772                                         {
1773                                         const unsigned char *out = NULL;
1774                                         unsigned short outlen = 0;
1775                                         int cb_retval = 0;
1776
1777                                         /* NULL callback or -1 omits extension */
1778                                         if (!record->fn2)
1779                                                 break;
1780                                         cb_retval = record->fn2(s, record->ext_type,
1781                                                                 &out, &outlen,
1782                                                                 record->arg);
1783                                         if (cb_retval == 0)
1784                                                 return NULL; /* error */
1785                                         if (cb_retval == -1)
1786                                                 break; /* skip this extension */
1787                                         if (limit < ret + 4 + outlen)
1788                                                 return NULL;
1789                                         s2n(record->ext_type, ret);
1790                                         s2n(outlen, ret);
1791                                         memcpy(ret, out, outlen);
1792                                         ret += outlen;
1793                                         break;
1794                                         }
1795                                 }
1796                         }
1797                 }
1798
1799         if (s->s3->alpn_selected)
1800                 {
1801                 const unsigned char *selected = s->s3->alpn_selected;
1802                 unsigned len = s->s3->alpn_selected_len;
1803
1804                 if ((long)(limit - ret - 4 - 2 - 1 - len) < 0)
1805                         return NULL;
1806                 s2n(TLSEXT_TYPE_application_layer_protocol_negotiation,ret);
1807                 s2n(3 + len,ret);
1808                 s2n(1 + len,ret);
1809                 *ret++ = len;
1810                 memcpy(ret, selected, len);
1811                 ret += len;
1812                 }
1813
1814         if ((extdatalen = ret-p-2)== 0) 
1815                 return p;
1816
1817         s2n(extdatalen,p);
1818         return ret;
1819         }
1820
1821 /* tls1_alpn_handle_client_hello is called to process the ALPN extension in a
1822  * ClientHello.
1823  *   data: the contents of the extension, not including the type and length.
1824  *   data_len: the number of bytes in |data|
1825  *   al: a pointer to the alert value to send in the event of a non-zero
1826  *       return.
1827  *
1828  *   returns: 0 on success. */
1829 static int tls1_alpn_handle_client_hello(SSL *s, const unsigned char *data,
1830                                          unsigned data_len, int *al)
1831         {
1832         unsigned i;
1833         unsigned proto_len;
1834         const unsigned char *selected;
1835         unsigned char selected_len;
1836         int r;
1837
1838         if (s->ctx->alpn_select_cb == NULL)
1839                 return 0;
1840
1841         if (data_len < 2)
1842                 goto parse_error;
1843
1844         /* data should contain a uint16 length followed by a series of 8-bit,
1845          * length-prefixed strings. */
1846         i = ((unsigned) data[0]) << 8 |
1847             ((unsigned) data[1]);
1848         data_len -= 2;
1849         data += 2;
1850         if (data_len != i)
1851                 goto parse_error;
1852
1853         if (data_len < 2)
1854                 goto parse_error;
1855
1856         for (i = 0; i < data_len;)
1857                 {
1858                 proto_len = data[i];
1859                 i++;
1860
1861                 if (proto_len == 0)
1862                         goto parse_error;
1863
1864                 if (i + proto_len < i || i + proto_len > data_len)
1865                         goto parse_error;
1866
1867                 i += proto_len;
1868                 }
1869
1870         r = s->ctx->alpn_select_cb(s, &selected, &selected_len, data, data_len,
1871                                    s->ctx->alpn_select_cb_arg);
1872         if (r == SSL_TLSEXT_ERR_OK) {
1873                 if (s->s3->alpn_selected)
1874                         OPENSSL_free(s->s3->alpn_selected);
1875                 s->s3->alpn_selected = OPENSSL_malloc(selected_len);
1876                 if (!s->s3->alpn_selected)
1877                         {
1878                         *al = SSL_AD_INTERNAL_ERROR;
1879                         return -1;
1880                         }
1881                 memcpy(s->s3->alpn_selected, selected, selected_len);
1882                 s->s3->alpn_selected_len = selected_len;
1883         }
1884         return 0;
1885
1886 parse_error:
1887         *al = SSL_AD_DECODE_ERROR;
1888         return -1;
1889         }
1890
1891 static int ssl_scan_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al) 
1892         {       
1893         unsigned short type;
1894         unsigned short size;
1895         unsigned short len;
1896         unsigned char *data = *p;
1897         int renegotiate_seen = 0;
1898         size_t i;
1899
1900         s->servername_done = 0;
1901         s->tlsext_status_type = -1;
1902 #ifndef OPENSSL_NO_NEXTPROTONEG
1903         s->s3->next_proto_neg_seen = 0;
1904 #endif
1905
1906         if (s->s3->alpn_selected)
1907                 {
1908                 OPENSSL_free(s->s3->alpn_selected);
1909                 s->s3->alpn_selected = NULL;
1910                 }
1911
1912 #ifndef OPENSSL_NO_HEARTBEATS
1913         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
1914                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
1915 #endif
1916         /* Clear any signature algorithms extension received */
1917         if (s->cert->peer_sigalgs)
1918                 {
1919                 OPENSSL_free(s->cert->peer_sigalgs);
1920                 s->cert->peer_sigalgs = NULL;
1921                 }
1922         /* Clear any shared sigtnature algorithms */
1923         if (s->cert->shared_sigalgs)
1924                 {
1925                 OPENSSL_free(s->cert->shared_sigalgs);
1926                 s->cert->shared_sigalgs = NULL;
1927                 }
1928         /* Clear certificate digests and validity flags */
1929         for (i = 0; i < SSL_PKEY_NUM; i++)
1930                 {
1931                 s->cert->pkeys[i].digest = NULL;
1932                 s->cert->pkeys[i].valid_flags = 0;
1933                 }
1934
1935         if (data >= (d+n-2))
1936                 goto ri_check;
1937         n2s(data,len);
1938
1939         if (data > (d+n-len)) 
1940                 goto ri_check;
1941
1942         while (data <= (d+n-4))
1943                 {
1944                 n2s(data,type);
1945                 n2s(data,size);
1946
1947                 if (data+size > (d+n))
1948                         goto ri_check;
1949 #if 0
1950                 fprintf(stderr,"Received extension type %d size %d\n",type,size);
1951 #endif
1952                 if (s->tlsext_debug_cb)
1953                         s->tlsext_debug_cb(s, 0, type, data, size,
1954                                                 s->tlsext_debug_arg);
1955 /* The servername extension is treated as follows:
1956
1957    - Only the hostname type is supported with a maximum length of 255.
1958    - The servername is rejected if too long or if it contains zeros,
1959      in which case an fatal alert is generated.
1960    - The servername field is maintained together with the session cache.
1961    - When a session is resumed, the servername call back invoked in order
1962      to allow the application to position itself to the right context. 
1963    - The servername is acknowledged if it is new for a session or when 
1964      it is identical to a previously used for the same session. 
1965      Applications can control the behaviour.  They can at any time
1966      set a 'desirable' servername for a new SSL object. This can be the
1967      case for example with HTTPS when a Host: header field is received and
1968      a renegotiation is requested. In this case, a possible servername
1969      presented in the new client hello is only acknowledged if it matches
1970      the value of the Host: field. 
1971    - Applications must  use SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
1972      if they provide for changing an explicit servername context for the session,
1973      i.e. when the session has been established with a servername extension. 
1974    - On session reconnect, the servername extension may be absent. 
1975
1976 */      
1977
1978                 if (type == TLSEXT_TYPE_server_name)
1979                         {
1980                         unsigned char *sdata;
1981                         int servname_type;
1982                         int dsize; 
1983                 
1984                         if (size < 2) 
1985                                 {
1986                                 *al = SSL_AD_DECODE_ERROR;
1987                                 return 0;
1988                                 }
1989                         n2s(data,dsize);  
1990                         size -= 2;
1991                         if (dsize > size  ) 
1992                                 {
1993                                 *al = SSL_AD_DECODE_ERROR;
1994                                 return 0;
1995                                 } 
1996
1997                         sdata = data;
1998                         while (dsize > 3) 
1999                                 {
2000                                 servname_type = *(sdata++); 
2001                                 n2s(sdata,len);
2002                                 dsize -= 3;
2003
2004                                 if (len > dsize) 
2005                                         {
2006                                         *al = SSL_AD_DECODE_ERROR;
2007                                         return 0;
2008                                         }
2009                                 if (s->servername_done == 0)
2010                                 switch (servname_type)
2011                                         {
2012                                 case TLSEXT_NAMETYPE_host_name:
2013                                         if (!s->hit)
2014                                                 {
2015                                                 if(s->session->tlsext_hostname)
2016                                                         {
2017                                                         *al = SSL_AD_DECODE_ERROR;
2018                                                         return 0;
2019                                                         }
2020                                                 if (len > TLSEXT_MAXLEN_host_name)
2021                                                         {
2022                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
2023                                                         return 0;
2024                                                         }
2025                                                 if ((s->session->tlsext_hostname = OPENSSL_malloc(len+1)) == NULL)
2026                                                         {
2027                                                         *al = TLS1_AD_INTERNAL_ERROR;
2028                                                         return 0;
2029                                                         }
2030                                                 memcpy(s->session->tlsext_hostname, sdata, len);
2031                                                 s->session->tlsext_hostname[len]='\0';
2032                                                 if (strlen(s->session->tlsext_hostname) != len) {
2033                                                         OPENSSL_free(s->session->tlsext_hostname);
2034                                                         s->session->tlsext_hostname = NULL;
2035                                                         *al = TLS1_AD_UNRECOGNIZED_NAME;
2036                                                         return 0;
2037                                                 }
2038                                                 s->servername_done = 1; 
2039
2040                                                 }
2041                                         else 
2042                                                 s->servername_done = s->session->tlsext_hostname
2043                                                         && strlen(s->session->tlsext_hostname) == len 
2044                                                         && strncmp(s->session->tlsext_hostname, (char *)sdata, len) == 0;
2045                                         
2046                                         break;
2047
2048                                 default:
2049                                         break;
2050                                         }
2051                                  
2052                                 dsize -= len;
2053                                 }
2054                         if (dsize != 0) 
2055                                 {
2056                                 *al = SSL_AD_DECODE_ERROR;
2057                                 return 0;
2058                                 }
2059
2060                         }
2061 #ifndef OPENSSL_NO_SRP
2062                 else if (type == TLSEXT_TYPE_srp)
2063                         {
2064                         if (size <= 0 || ((len = data[0])) != (size -1))
2065                                 {
2066                                 *al = SSL_AD_DECODE_ERROR;
2067                                 return 0;
2068                                 }
2069                         if (s->srp_ctx.login != NULL)
2070                                 {
2071                                 *al = SSL_AD_DECODE_ERROR;
2072                                 return 0;
2073                                 }
2074                         if ((s->srp_ctx.login = OPENSSL_malloc(len+1)) == NULL)
2075                                 return -1;
2076                         memcpy(s->srp_ctx.login, &data[1], len);
2077                         s->srp_ctx.login[len]='\0';
2078   
2079                         if (strlen(s->srp_ctx.login) != len) 
2080                                 {
2081                                 *al = SSL_AD_DECODE_ERROR;
2082                                 return 0;
2083                                 }
2084                         }
2085 #endif
2086
2087 #ifndef OPENSSL_NO_EC
2088                 else if (type == TLSEXT_TYPE_ec_point_formats)
2089                         {
2090                         unsigned char *sdata = data;
2091                         int ecpointformatlist_length = *(sdata++);
2092
2093                         if (ecpointformatlist_length != size - 1 || 
2094                                 ecpointformatlist_length < 1)
2095                                 {
2096                                 *al = TLS1_AD_DECODE_ERROR;
2097                                 return 0;
2098                                 }
2099                         if (!s->hit)
2100                                 {
2101                                 if(s->session->tlsext_ecpointformatlist)
2102                                         {
2103                                         OPENSSL_free(s->session->tlsext_ecpointformatlist);
2104                                         s->session->tlsext_ecpointformatlist = NULL;
2105                                         }
2106                                 s->session->tlsext_ecpointformatlist_length = 0;
2107                                 if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
2108                                         {
2109                                         *al = TLS1_AD_INTERNAL_ERROR;
2110                                         return 0;
2111                                         }
2112                                 s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
2113                                 memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
2114                                 }
2115 #if 0
2116                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ecpointformatlist (length=%i) ", s->session->tlsext_ecpointformatlist_length);
2117                         sdata = s->session->tlsext_ecpointformatlist;
2118                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2119                                 fprintf(stderr,"%i ",*(sdata++));
2120                         fprintf(stderr,"\n");
2121 #endif
2122                         }
2123                 else if (type == TLSEXT_TYPE_elliptic_curves)
2124                         {
2125                         unsigned char *sdata = data;
2126                         int ellipticcurvelist_length = (*(sdata++) << 8);
2127                         ellipticcurvelist_length += (*(sdata++));
2128
2129                         if (ellipticcurvelist_length != size - 2 ||
2130                                 ellipticcurvelist_length < 1)
2131                                 {
2132                                 *al = TLS1_AD_DECODE_ERROR;
2133                                 return 0;
2134                                 }
2135                         if (!s->hit)
2136                                 {
2137                                 if(s->session->tlsext_ellipticcurvelist)
2138                                         {
2139                                         *al = TLS1_AD_DECODE_ERROR;
2140                                         return 0;
2141                                         }
2142                                 s->session->tlsext_ellipticcurvelist_length = 0;
2143                                 if ((s->session->tlsext_ellipticcurvelist = OPENSSL_malloc(ellipticcurvelist_length)) == NULL)
2144                                         {
2145                                         *al = TLS1_AD_INTERNAL_ERROR;
2146                                         return 0;
2147                                         }
2148                                 s->session->tlsext_ellipticcurvelist_length = ellipticcurvelist_length;
2149                                 memcpy(s->session->tlsext_ellipticcurvelist, sdata, ellipticcurvelist_length);
2150                                 }
2151 #if 0
2152                         fprintf(stderr,"ssl_parse_clienthello_tlsext s->session->tlsext_ellipticcurvelist (length=%i) ", s->session->tlsext_ellipticcurvelist_length);
2153                         sdata = s->session->tlsext_ellipticcurvelist;
2154                         for (i = 0; i < s->session->tlsext_ellipticcurvelist_length; i++)
2155                                 fprintf(stderr,"%i ",*(sdata++));
2156                         fprintf(stderr,"\n");
2157 #endif
2158                         }
2159 #endif /* OPENSSL_NO_EC */
2160 #ifdef TLSEXT_TYPE_opaque_prf_input
2161                 else if (type == TLSEXT_TYPE_opaque_prf_input)
2162                         {
2163                         unsigned char *sdata = data;
2164
2165                         if (size < 2)
2166                                 {
2167                                 *al = SSL_AD_DECODE_ERROR;
2168                                 return 0;
2169                                 }
2170                         n2s(sdata, s->s3->client_opaque_prf_input_len);
2171                         if (s->s3->client_opaque_prf_input_len != size - 2)
2172                                 {
2173                                 *al = SSL_AD_DECODE_ERROR;
2174                                 return 0;
2175                                 }
2176
2177                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
2178                                 OPENSSL_free(s->s3->client_opaque_prf_input);
2179                         if (s->s3->client_opaque_prf_input_len == 0)
2180                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2181                         else
2182                                 s->s3->client_opaque_prf_input = BUF_memdup(sdata, s->s3->client_opaque_prf_input_len);
2183                         if (s->s3->client_opaque_prf_input == NULL)
2184                                 {
2185                                 *al = TLS1_AD_INTERNAL_ERROR;
2186                                 return 0;
2187                                 }
2188                         }
2189 #endif
2190                 else if (type == TLSEXT_TYPE_session_ticket)
2191                         {
2192                         if (s->tls_session_ticket_ext_cb &&
2193                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
2194                                 {
2195                                 *al = TLS1_AD_INTERNAL_ERROR;
2196                                 return 0;
2197                                 }
2198                         }
2199                 else if (type == TLSEXT_TYPE_renegotiate)
2200                         {
2201                         if(!ssl_parse_clienthello_renegotiate_ext(s, data, size, al))
2202                                 return 0;
2203                         renegotiate_seen = 1;
2204                         }
2205                 else if (type == TLSEXT_TYPE_signature_algorithms)
2206                         {
2207                         int dsize;
2208                         if (s->cert->peer_sigalgs || size < 2) 
2209                                 {
2210                                 *al = SSL_AD_DECODE_ERROR;
2211                                 return 0;
2212                                 }
2213                         n2s(data,dsize);
2214                         size -= 2;
2215                         if (dsize != size || dsize & 1 || !dsize) 
2216                                 {
2217                                 *al = SSL_AD_DECODE_ERROR;
2218                                 return 0;
2219                                 }
2220                         if (!tls1_process_sigalgs(s, data, dsize))
2221                                 {
2222                                 *al = SSL_AD_DECODE_ERROR;
2223                                 return 0;
2224                                 }
2225                         /* If sigalgs received and no shared algorithms fatal
2226                          * error.
2227                          */
2228                         if (s->cert->peer_sigalgs && !s->cert->shared_sigalgs)
2229                                 {
2230                                 SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
2231                                         SSL_R_NO_SHARED_SIGATURE_ALGORITHMS);
2232                                 *al = SSL_AD_ILLEGAL_PARAMETER;
2233                                 return 0;
2234                                 }
2235                         }
2236                 else if (type == TLSEXT_TYPE_status_request
2237                          && s->ctx->tlsext_status_cb)
2238                         {
2239                 
2240                         if (size < 5) 
2241                                 {
2242                                 *al = SSL_AD_DECODE_ERROR;
2243                                 return 0;
2244                                 }
2245
2246                         s->tlsext_status_type = *data++;
2247                         size--;
2248                         if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
2249                                 {
2250                                 const unsigned char *sdata;
2251                                 int dsize;
2252                                 /* Read in responder_id_list */
2253                                 n2s(data,dsize);
2254                                 size -= 2;
2255                                 if (dsize > size  ) 
2256                                         {
2257                                         *al = SSL_AD_DECODE_ERROR;
2258                                         return 0;
2259                                         }
2260                                 while (dsize > 0)
2261                                         {
2262                                         OCSP_RESPID *id;
2263                                         int idsize;
2264                                         if (dsize < 4)
2265                                                 {
2266                                                 *al = SSL_AD_DECODE_ERROR;
2267                                                 return 0;
2268                                                 }
2269                                         n2s(data, idsize);
2270                                         dsize -= 2 + idsize;
2271                                         size -= 2 + idsize;
2272                                         if (dsize < 0)
2273                                                 {
2274                                                 *al = SSL_AD_DECODE_ERROR;
2275                                                 return 0;
2276                                                 }
2277                                         sdata = data;
2278                                         data += idsize;
2279                                         id = d2i_OCSP_RESPID(NULL,
2280                                                                 &sdata, idsize);
2281                                         if (!id)
2282                                                 {
2283                                                 *al = SSL_AD_DECODE_ERROR;
2284                                                 return 0;
2285                                                 }
2286                                         if (data != sdata)
2287                                                 {
2288                                                 OCSP_RESPID_free(id);
2289                                                 *al = SSL_AD_DECODE_ERROR;
2290                                                 return 0;
2291                                                 }
2292                                         if (!s->tlsext_ocsp_ids
2293                                                 && !(s->tlsext_ocsp_ids =
2294                                                 sk_OCSP_RESPID_new_null()))
2295                                                 {
2296                                                 OCSP_RESPID_free(id);
2297                                                 *al = SSL_AD_INTERNAL_ERROR;
2298                                                 return 0;
2299                                                 }
2300                                         if (!sk_OCSP_RESPID_push(
2301                                                         s->tlsext_ocsp_ids, id))
2302                                                 {
2303                                                 OCSP_RESPID_free(id);
2304                                                 *al = SSL_AD_INTERNAL_ERROR;
2305                                                 return 0;
2306                                                 }
2307                                         }
2308
2309                                 /* Read in request_extensions */
2310                                 if (size < 2)
2311                                         {
2312                                         *al = SSL_AD_DECODE_ERROR;
2313                                         return 0;
2314                                         }
2315                                 n2s(data,dsize);
2316                                 size -= 2;
2317                                 if (dsize != size)
2318                                         {
2319                                         *al = SSL_AD_DECODE_ERROR;
2320                                         return 0;
2321                                         }
2322                                 sdata = data;
2323                                 if (dsize > 0)
2324                                         {
2325                                         if (s->tlsext_ocsp_exts)
2326                                                 {
2327                                                 sk_X509_EXTENSION_pop_free(s->tlsext_ocsp_exts,
2328                                                                            X509_EXTENSION_free);
2329                                                 }
2330
2331                                         s->tlsext_ocsp_exts =
2332                                                 d2i_X509_EXTENSIONS(NULL,
2333                                                         &sdata, dsize);
2334                                         if (!s->tlsext_ocsp_exts
2335                                                 || (data + dsize != sdata))
2336                                                 {
2337                                                 *al = SSL_AD_DECODE_ERROR;
2338                                                 return 0;
2339                                                 }
2340                                         }
2341                                 }
2342                                 /* We don't know what to do with any other type
2343                                 * so ignore it.
2344                                 */
2345                                 else
2346                                         s->tlsext_status_type = -1;
2347                         }
2348 #ifndef OPENSSL_NO_HEARTBEATS
2349                 else if (type == TLSEXT_TYPE_heartbeat)
2350                         {
2351                         switch(data[0])
2352                                 {
2353                                 case 0x01:      /* Client allows us to send HB requests */
2354                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2355                                                         break;
2356                                 case 0x02:      /* Client doesn't accept HB requests */
2357                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2358                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2359                                                         break;
2360                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
2361                                                         return 0;
2362                                 }
2363                         }
2364 #endif
2365 #ifndef OPENSSL_NO_NEXTPROTONEG
2366                 else if (type == TLSEXT_TYPE_next_proto_neg &&
2367                          s->s3->tmp.finish_md_len == 0 &&
2368                          s->s3->alpn_selected == NULL)
2369                         {
2370                         /* We shouldn't accept this extension on a
2371                          * renegotiation.
2372                          *
2373                          * s->new_session will be set on renegotiation, but we
2374                          * probably shouldn't rely that it couldn't be set on
2375                          * the initial renegotation too in certain cases (when
2376                          * there's some other reason to disallow resuming an
2377                          * earlier session -- the current code won't be doing
2378                          * anything like that, but this might change).
2379
2380                          * A valid sign that there's been a previous handshake
2381                          * in this connection is if s->s3->tmp.finish_md_len >
2382                          * 0.  (We are talking about a check that will happen
2383                          * in the Hello protocol round, well before a new
2384                          * Finished message could have been computed.) */
2385                         s->s3->next_proto_neg_seen = 1;
2386                         }
2387 #endif
2388
2389                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation &&
2390                          s->ctx->alpn_select_cb &&
2391                          s->s3->tmp.finish_md_len == 0)
2392                         {
2393                         if (tls1_alpn_handle_client_hello(s, data, size, al) != 0)
2394                                 return 0;
2395                         /* ALPN takes precedence over NPN. */
2396                         s->s3->next_proto_neg_seen = 0;
2397                         }
2398
2399                 /* session ticket processed earlier */
2400                 else if (type == TLSEXT_TYPE_use_srtp)
2401                         {
2402                         if(ssl_parse_clienthello_use_srtp_ext(s, data, size,
2403                                                               al))
2404                                 return 0;
2405                         }
2406
2407                 else if (type == TLSEXT_TYPE_server_authz)
2408                         {
2409                         unsigned char *sdata = data;
2410                         unsigned char server_authz_dataformatlist_length;
2411
2412                         if (size == 0)
2413                                 {
2414                                 *al = TLS1_AD_DECODE_ERROR;
2415                                 return 0;
2416                                 }
2417
2418                         server_authz_dataformatlist_length = *(sdata++);
2419
2420                         if (server_authz_dataformatlist_length != size - 1)
2421                                 {
2422                                 *al = TLS1_AD_DECODE_ERROR;
2423                                 return 0;
2424                                 }
2425
2426                         /* Successful session resumption uses the same authz
2427                          * information as the original session so we ignore this
2428                          * in the case of a session resumption. */
2429                         if (!s->hit)
2430                                 {
2431                                 if (s->s3->tlsext_authz_client_types != NULL)
2432                                         OPENSSL_free(s->s3->tlsext_authz_client_types);
2433                                 s->s3->tlsext_authz_client_types =
2434                                         OPENSSL_malloc(server_authz_dataformatlist_length);
2435                                 if (!s->s3->tlsext_authz_client_types)
2436                                         {
2437                                         *al = TLS1_AD_INTERNAL_ERROR;
2438                                         return 0;
2439                                         }
2440
2441                                 s->s3->tlsext_authz_client_types_len =
2442                                         server_authz_dataformatlist_length;
2443                                 memcpy(s->s3->tlsext_authz_client_types,
2444                                        sdata,
2445                                        server_authz_dataformatlist_length);
2446
2447                                 /* Sort the types in order to check for duplicates. */
2448                                 qsort(s->s3->tlsext_authz_client_types,
2449                                       server_authz_dataformatlist_length,
2450                                       1 /* element size */,
2451                                       byte_compare);
2452
2453                                 for (i = 0; i < server_authz_dataformatlist_length; i++)
2454                                         {
2455                                         if (i > 0 &&
2456                                             s->s3->tlsext_authz_client_types[i] ==
2457                                               s->s3->tlsext_authz_client_types[i-1])
2458                                                 {
2459                                                 *al = TLS1_AD_DECODE_ERROR;
2460                                                 return 0;
2461                                                 }
2462                                         }
2463                                 }
2464                         }
2465
2466                 /* If this ClientHello extension was unhandled and this is 
2467                  * a nonresumed connection, check whether the extension is a 
2468                  * custom TLS Extension (has a custom_srv_ext_record), and if
2469                  * so call the callback and record the extension number so that
2470                  * an appropriate ServerHello may be later returned.
2471                  */
2472                 else if (!s->hit && s->ctx->custom_srv_ext_records_count)
2473                         {
2474                         custom_srv_ext_record *record;
2475
2476                         for (i=0; i < s->ctx->custom_srv_ext_records_count; i++)
2477                                 {
2478                                 record = &s->ctx->custom_srv_ext_records[i];
2479                                 if (type == record->ext_type)
2480                                         {
2481                                         size_t j;
2482
2483                                         /* Error on duplicate TLS Extensions */
2484                                         for (j = 0; j < s->s3->tlsext_custom_types_count; j++)
2485                                                 {
2486                                                 if (type == s->s3->tlsext_custom_types[j])
2487                                                         {
2488                                                         *al = TLS1_AD_DECODE_ERROR;
2489                                                         return 0;
2490                                                         }
2491                                                 }
2492
2493                                         /* NULL callback still notes the extension */ 
2494                                         if (record->fn1 && !record->fn1(s, type, data, size, al, record->arg))
2495                                                 return 0;
2496                                                 
2497                                         /* Add the (non-duplicated) entry */
2498                                         s->s3->tlsext_custom_types_count++;
2499                                         s->s3->tlsext_custom_types = OPENSSL_realloc(
2500                                                         s->s3->tlsext_custom_types,
2501                                                         s->s3->tlsext_custom_types_count * 2);
2502                                         if (s->s3->tlsext_custom_types == NULL)
2503                                                 {
2504                                                 s->s3->tlsext_custom_types = 0;
2505                                                 *al = TLS1_AD_INTERNAL_ERROR;
2506                                                 return 0;
2507                                                 }
2508                                         s->s3->tlsext_custom_types[
2509                                                         s->s3->tlsext_custom_types_count - 1] = type;
2510                                         }                                               
2511                                 }
2512                         }
2513
2514                 data+=size;
2515                 }
2516
2517         *p = data;
2518
2519         ri_check:
2520
2521         /* Need RI if renegotiating */
2522
2523         if (!renegotiate_seen && s->renegotiate &&
2524                 !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2525                 {
2526                 *al = SSL_AD_HANDSHAKE_FAILURE;
2527                 SSLerr(SSL_F_SSL_SCAN_CLIENTHELLO_TLSEXT,
2528                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2529                 return 0;
2530                 }
2531         /* If no signature algorithms extension set default values */
2532         if (!s->cert->peer_sigalgs)
2533                 ssl_cert_set_default_md(s->cert);
2534
2535         return 1;
2536         }
2537
2538 int ssl_parse_clienthello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n) 
2539         {
2540         int al = -1;
2541         if (ssl_scan_clienthello_tlsext(s, p, d, n, &al) <= 0) 
2542                 {
2543                 ssl3_send_alert(s,SSL3_AL_FATAL,al); 
2544                 return 0;
2545                 }
2546
2547         if (ssl_check_clienthello_tlsext_early(s) <= 0) 
2548                 {
2549                 SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_TLSEXT,SSL_R_CLIENTHELLO_TLSEXT);
2550                 return 0;
2551                 }
2552         return 1;
2553 }
2554
2555 #ifndef OPENSSL_NO_NEXTPROTONEG
2556 /* ssl_next_proto_validate validates a Next Protocol Negotiation block. No
2557  * elements of zero length are allowed and the set of elements must exactly fill
2558  * the length of the block. */
2559 static char ssl_next_proto_validate(unsigned char *d, unsigned len)
2560         {
2561         unsigned int off = 0;
2562
2563         while (off < len)
2564                 {
2565                 if (d[off] == 0)
2566                         return 0;
2567                 off += d[off];
2568                 off++;
2569                 }
2570
2571         return off == len;
2572         }
2573 #endif
2574
2575 static int ssl_scan_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n, int *al)
2576         {
2577         unsigned short length;
2578         unsigned short type;
2579         unsigned short size;
2580         unsigned char *data = *p;
2581         int tlsext_servername = 0;
2582         int renegotiate_seen = 0;
2583
2584 #ifndef OPENSSL_NO_NEXTPROTONEG
2585         s->s3->next_proto_neg_seen = 0;
2586 #endif
2587
2588         if (s->s3->alpn_selected)
2589                 {
2590                 OPENSSL_free(s->s3->alpn_selected);
2591                 s->s3->alpn_selected = NULL;
2592                 }
2593
2594 #ifndef OPENSSL_NO_HEARTBEATS
2595         s->tlsext_heartbeat &= ~(SSL_TLSEXT_HB_ENABLED |
2596                                SSL_TLSEXT_HB_DONT_SEND_REQUESTS);
2597 #endif
2598
2599         if (data >= (d+n-2))
2600                 goto ri_check;
2601
2602         n2s(data,length);
2603         if (data+length != d+n)
2604                 {
2605                 *al = SSL_AD_DECODE_ERROR;
2606                 return 0;
2607                 }
2608
2609         while(data <= (d+n-4))
2610                 {
2611                 n2s(data,type);
2612                 n2s(data,size);
2613
2614                 if (data+size > (d+n))
2615                         goto ri_check;
2616
2617                 if (s->tlsext_debug_cb)
2618                         s->tlsext_debug_cb(s, 1, type, data, size,
2619                                                 s->tlsext_debug_arg);
2620
2621                 if (type == TLSEXT_TYPE_server_name)
2622                         {
2623                         if (s->tlsext_hostname == NULL || size > 0)
2624                                 {
2625                                 *al = TLS1_AD_UNRECOGNIZED_NAME;
2626                                 return 0;
2627                                 }
2628                         tlsext_servername = 1;   
2629                         }
2630
2631 #ifndef OPENSSL_NO_EC
2632                 else if (type == TLSEXT_TYPE_ec_point_formats)
2633                         {
2634                         unsigned char *sdata = data;
2635                         int ecpointformatlist_length = *(sdata++);
2636
2637                         if (ecpointformatlist_length != size - 1)
2638                                 {
2639                                 *al = TLS1_AD_DECODE_ERROR;
2640                                 return 0;
2641                                 }
2642                         s->session->tlsext_ecpointformatlist_length = 0;
2643                         if (s->session->tlsext_ecpointformatlist != NULL) OPENSSL_free(s->session->tlsext_ecpointformatlist);
2644                         if ((s->session->tlsext_ecpointformatlist = OPENSSL_malloc(ecpointformatlist_length)) == NULL)
2645                                 {
2646                                 *al = TLS1_AD_INTERNAL_ERROR;
2647                                 return 0;
2648                                 }
2649                         s->session->tlsext_ecpointformatlist_length = ecpointformatlist_length;
2650                         memcpy(s->session->tlsext_ecpointformatlist, sdata, ecpointformatlist_length);
2651 #if 0
2652                         fprintf(stderr,"ssl_parse_serverhello_tlsext s->session->tlsext_ecpointformatlist ");
2653                         sdata = s->session->tlsext_ecpointformatlist;
2654                         for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
2655                                 fprintf(stderr,"%i ",*(sdata++));
2656                         fprintf(stderr,"\n");
2657 #endif
2658                         }
2659 #endif /* OPENSSL_NO_EC */
2660
2661                 else if (type == TLSEXT_TYPE_session_ticket)
2662                         {
2663                         if (s->tls_session_ticket_ext_cb &&
2664                             !s->tls_session_ticket_ext_cb(s, data, size, s->tls_session_ticket_ext_cb_arg))
2665                                 {
2666                                 *al = TLS1_AD_INTERNAL_ERROR;
2667                                 return 0;
2668                                 }
2669                         if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
2670                                 || (size > 0))
2671                                 {
2672                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2673                                 return 0;
2674                                 }
2675                         s->tlsext_ticket_expected = 1;
2676                         }
2677 #ifdef TLSEXT_TYPE_opaque_prf_input
2678                 else if (type == TLSEXT_TYPE_opaque_prf_input)
2679                         {
2680                         unsigned char *sdata = data;
2681
2682                         if (size < 2)
2683                                 {
2684                                 *al = SSL_AD_DECODE_ERROR;
2685                                 return 0;
2686                                 }
2687                         n2s(sdata, s->s3->server_opaque_prf_input_len);
2688                         if (s->s3->server_opaque_prf_input_len != size - 2)
2689                                 {
2690                                 *al = SSL_AD_DECODE_ERROR;
2691                                 return 0;
2692                                 }
2693                         
2694                         if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
2695                                 OPENSSL_free(s->s3->server_opaque_prf_input);
2696                         if (s->s3->server_opaque_prf_input_len == 0)
2697                                 s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2698                         else
2699                                 s->s3->server_opaque_prf_input = BUF_memdup(sdata, s->s3->server_opaque_prf_input_len);
2700
2701                         if (s->s3->server_opaque_prf_input == NULL)
2702                                 {
2703                                 *al = TLS1_AD_INTERNAL_ERROR;
2704                                 return 0;
2705                                 }
2706                         }
2707 #endif
2708                 else if (type == TLSEXT_TYPE_status_request)
2709                         {
2710                         /* MUST be empty and only sent if we've requested
2711                          * a status request message.
2712                          */ 
2713                         if ((s->tlsext_status_type == -1) || (size > 0))
2714                                 {
2715                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2716                                 return 0;
2717                                 }
2718                         /* Set flag to expect CertificateStatus message */
2719                         s->tlsext_status_expected = 1;
2720                         }
2721 #ifndef OPENSSL_NO_NEXTPROTONEG
2722                 else if (type == TLSEXT_TYPE_next_proto_neg &&
2723                          s->s3->tmp.finish_md_len == 0)
2724                         {
2725                         unsigned char *selected;
2726                         unsigned char selected_len;
2727
2728                         /* We must have requested it. */
2729                         if (s->ctx->next_proto_select_cb == NULL)
2730                                 {
2731                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2732                                 return 0;
2733                                 }
2734                         /* The data must be valid */
2735                         if (!ssl_next_proto_validate(data, size))
2736                                 {
2737                                 *al = TLS1_AD_DECODE_ERROR;
2738                                 return 0;
2739                                 }
2740                         if (s->ctx->next_proto_select_cb(s, &selected, &selected_len, data, size, s->ctx->next_proto_select_cb_arg) != SSL_TLSEXT_ERR_OK)
2741                                 {
2742                                 *al = TLS1_AD_INTERNAL_ERROR;
2743                                 return 0;
2744                                 }
2745                         s->next_proto_negotiated = OPENSSL_malloc(selected_len);
2746                         if (!s->next_proto_negotiated)
2747                                 {
2748                                 *al = TLS1_AD_INTERNAL_ERROR;
2749                                 return 0;
2750                                 }
2751                         memcpy(s->next_proto_negotiated, selected, selected_len);
2752                         s->next_proto_negotiated_len = selected_len;
2753                         s->s3->next_proto_neg_seen = 1;
2754                         }
2755 #endif
2756
2757                 else if (type == TLSEXT_TYPE_application_layer_protocol_negotiation)
2758                         {
2759                         unsigned len;
2760
2761                         /* We must have requested it. */
2762                         if (s->alpn_client_proto_list == NULL)
2763                                 {
2764                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2765                                 return 0;
2766                                 }
2767                         if (size < 4)
2768                                 {
2769                                 *al = TLS1_AD_DECODE_ERROR;
2770                                 return 0;
2771                                 }
2772                         /* The extension data consists of:
2773                          *   uint16 list_length
2774                          *   uint8 proto_length;
2775                          *   uint8 proto[proto_length]; */
2776                         len = data[0];
2777                         len <<= 8;
2778                         len |= data[1];
2779                         if (len != (unsigned) size - 2)
2780                                 {
2781                                 *al = TLS1_AD_DECODE_ERROR;
2782                                 return 0;
2783                                 }
2784                         len = data[2];
2785                         if (len != (unsigned) size - 3)
2786                                 {
2787                                 *al = TLS1_AD_DECODE_ERROR;
2788                                 return 0;
2789                                 }
2790                         if (s->s3->alpn_selected)
2791                                 OPENSSL_free(s->s3->alpn_selected);
2792                         s->s3->alpn_selected = OPENSSL_malloc(len);
2793                         if (!s->s3->alpn_selected)
2794                                 {
2795                                 *al = TLS1_AD_INTERNAL_ERROR;
2796                                 return 0;
2797                                 }
2798                         memcpy(s->s3->alpn_selected, data + 3, len);
2799                         s->s3->alpn_selected_len = len;
2800                         }
2801
2802                 else if (type == TLSEXT_TYPE_renegotiate)
2803                         {
2804                         if(!ssl_parse_serverhello_renegotiate_ext(s, data, size, al))
2805                                 return 0;
2806                         renegotiate_seen = 1;
2807                         }
2808 #ifndef OPENSSL_NO_HEARTBEATS
2809                 else if (type == TLSEXT_TYPE_heartbeat)
2810                         {
2811                         switch(data[0])
2812                                 {
2813                                 case 0x01:      /* Server allows us to send HB requests */
2814                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2815                                                         break;
2816                                 case 0x02:      /* Server doesn't accept HB requests */
2817                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_ENABLED;
2818                                                         s->tlsext_heartbeat |= SSL_TLSEXT_HB_DONT_SEND_REQUESTS;
2819                                                         break;
2820                                 default:        *al = SSL_AD_ILLEGAL_PARAMETER;
2821                                                         return 0;
2822                                 }
2823                         }
2824 #endif
2825                 else if (type == TLSEXT_TYPE_use_srtp)
2826                         {
2827                         if(ssl_parse_serverhello_use_srtp_ext(s, data, size,
2828                                                               al))
2829                                 return 0;
2830                         }
2831
2832                 else if (type == TLSEXT_TYPE_server_authz)
2833                         {
2834                         /* We only support audit proofs. It's an error to send
2835                          * an authz hello extension if the client
2836                          * didn't request a proof. */
2837                         unsigned char *sdata = data;
2838                         unsigned char server_authz_dataformatlist_length;
2839
2840                         if (!s->ctx->tlsext_authz_server_audit_proof_cb)
2841                                 {
2842                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2843                                 return 0;
2844                                 }
2845
2846                         if (!size)
2847                                 {
2848                                 *al = TLS1_AD_DECODE_ERROR;
2849                                 return 0;
2850                                 }
2851
2852                         server_authz_dataformatlist_length = *(sdata++);
2853                         if (server_authz_dataformatlist_length != size - 1)
2854                                 {
2855                                 *al = TLS1_AD_DECODE_ERROR;
2856                                 return 0;
2857                                 }
2858
2859                         /* We only support audit proofs, so a legal ServerHello
2860                          * authz list contains exactly one entry. */
2861                         if (server_authz_dataformatlist_length != 1 ||
2862                                 sdata[0] != TLSEXT_AUTHZDATAFORMAT_audit_proof)
2863                                 {
2864                                 *al = TLS1_AD_UNSUPPORTED_EXTENSION;
2865                                 return 0;
2866                                 }
2867
2868                         s->s3->tlsext_authz_server_promised = 1;
2869                         }
2870
2871                 /* If this extension type was not otherwise handled, but 
2872                  * matches a custom_cli_ext_record, then send it to the c
2873                  * callback */
2874                 else if (s->ctx->custom_cli_ext_records_count)
2875                         {
2876                         size_t i;
2877                         custom_cli_ext_record* record;
2878
2879                         for (i = 0; i < s->ctx->custom_cli_ext_records_count; i++)
2880                                 {
2881                                 record = &s->ctx->custom_cli_ext_records[i];
2882                                 if (record->ext_type == type)
2883                                         {
2884                                         if (record->fn2 && !record->fn2(s, type, data, size, al, record->arg))
2885                                                 return 0;
2886                                         break;
2887                                         }
2888                                 }                       
2889                         }
2890  
2891                 data += size;
2892                 }
2893
2894         if (data != d+n)
2895                 {
2896                 *al = SSL_AD_DECODE_ERROR;
2897                 return 0;
2898                 }
2899
2900         if (!s->hit && tlsext_servername == 1)
2901                 {
2902                 if (s->tlsext_hostname)
2903                         {
2904                         if (s->session->tlsext_hostname == NULL)
2905                                 {
2906                                 s->session->tlsext_hostname = BUF_strdup(s->tlsext_hostname);   
2907                                 if (!s->session->tlsext_hostname)
2908                                         {
2909                                         *al = SSL_AD_UNRECOGNIZED_NAME;
2910                                         return 0;
2911                                         }
2912                                 }
2913                         else 
2914                                 {
2915                                 *al = SSL_AD_DECODE_ERROR;
2916                                 return 0;
2917                                 }
2918                         }
2919                 }
2920
2921         *p = data;
2922
2923         ri_check:
2924
2925         /* Determine if we need to see RI. Strictly speaking if we want to
2926          * avoid an attack we should *always* see RI even on initial server
2927          * hello because the client doesn't see any renegotiation during an
2928          * attack. However this would mean we could not connect to any server
2929          * which doesn't support RI so for the immediate future tolerate RI
2930          * absence on initial connect only.
2931          */
2932         if (!renegotiate_seen
2933                 && !(s->options & SSL_OP_LEGACY_SERVER_CONNECT)
2934                 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
2935                 {
2936                 *al = SSL_AD_HANDSHAKE_FAILURE;
2937                 SSLerr(SSL_F_SSL_SCAN_SERVERHELLO_TLSEXT,
2938                                 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
2939                 return 0;
2940                 }
2941
2942         return 1;
2943         }
2944
2945
2946 int ssl_prepare_clienthello_tlsext(SSL *s)
2947         {
2948
2949 #ifdef TLSEXT_TYPE_opaque_prf_input
2950         {
2951                 int r = 1;
2952         
2953                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
2954                         {
2955                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
2956                         if (!r)
2957                                 return -1;
2958                         }
2959
2960                 if (s->tlsext_opaque_prf_input != NULL)
2961                         {
2962                         if (s->s3->client_opaque_prf_input != NULL) /* shouldn't really happen */
2963                                 OPENSSL_free(s->s3->client_opaque_prf_input);
2964
2965                         if (s->tlsext_opaque_prf_input_len == 0)
2966                                 s->s3->client_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
2967                         else
2968                                 s->s3->client_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
2969                         if (s->s3->client_opaque_prf_input == NULL)
2970                                 {
2971                                 SSLerr(SSL_F_SSL_PREPARE_CLIENTHELLO_TLSEXT,ERR_R_MALLOC_FAILURE);
2972                                 return -1;
2973                                 }
2974                         s->s3->client_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
2975                         }
2976
2977                 if (r == 2)
2978                         /* at callback's request, insist on receiving an appropriate server opaque PRF input */
2979                         s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
2980         }
2981 #endif
2982
2983         return 1;
2984         }
2985
2986 int ssl_prepare_serverhello_tlsext(SSL *s)
2987         {
2988         return 1;
2989         }
2990
2991 static int ssl_check_clienthello_tlsext_early(SSL *s)
2992         {
2993         int ret=SSL_TLSEXT_ERR_NOACK;
2994         int al = SSL_AD_UNRECOGNIZED_NAME;
2995
2996 #ifndef OPENSSL_NO_EC
2997         /* The handling of the ECPointFormats extension is done elsewhere, namely in 
2998          * ssl3_choose_cipher in s3_lib.c.
2999          */
3000         /* The handling of the EllipticCurves extension is done elsewhere, namely in 
3001          * ssl3_choose_cipher in s3_lib.c.
3002          */
3003 #endif
3004
3005         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
3006                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
3007         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
3008                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
3009
3010 #ifdef TLSEXT_TYPE_opaque_prf_input
3011         {
3012                 /* This sort of belongs into ssl_prepare_serverhello_tlsext(),
3013                  * but we might be sending an alert in response to the client hello,
3014                  * so this has to happen here in
3015                  * ssl_check_clienthello_tlsext_early(). */
3016
3017                 int r = 1;
3018         
3019                 if (s->ctx->tlsext_opaque_prf_input_callback != 0)
3020                         {
3021                         r = s->ctx->tlsext_opaque_prf_input_callback(s, NULL, 0, s->ctx->tlsext_opaque_prf_input_callback_arg);
3022                         if (!r)
3023                                 {
3024                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3025                                 al = SSL_AD_INTERNAL_ERROR;
3026                                 goto err;
3027                                 }
3028                         }
3029
3030                 if (s->s3->server_opaque_prf_input != NULL) /* shouldn't really happen */
3031                         OPENSSL_free(s->s3->server_opaque_prf_input);
3032                 s->s3->server_opaque_prf_input = NULL;
3033
3034                 if (s->tlsext_opaque_prf_input != NULL)
3035                         {
3036                         if (s->s3->client_opaque_prf_input != NULL &&
3037                                 s->s3->client_opaque_prf_input_len == s->tlsext_opaque_prf_input_len)
3038                                 {
3039                                 /* can only use this extension if we have a server opaque PRF input
3040                                  * of the same length as the client opaque PRF input! */
3041
3042                                 if (s->tlsext_opaque_prf_input_len == 0)
3043                                         s->s3->server_opaque_prf_input = OPENSSL_malloc(1); /* dummy byte just to get non-NULL */
3044                                 else
3045                                         s->s3->server_opaque_prf_input = BUF_memdup(s->tlsext_opaque_prf_input, s->tlsext_opaque_prf_input_len);
3046                                 if (s->s3->server_opaque_prf_input == NULL)
3047                                         {
3048                                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3049                                         al = SSL_AD_INTERNAL_ERROR;
3050                                         goto err;
3051                                         }
3052                                 s->s3->server_opaque_prf_input_len = s->tlsext_opaque_prf_input_len;
3053                                 }
3054                         }
3055
3056                 if (r == 2 && s->s3->server_opaque_prf_input == NULL)
3057                         {
3058                         /* The callback wants to enforce use of the extension,
3059                          * but we can't do that with the client opaque PRF input;
3060                          * abort the handshake.
3061                          */
3062                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3063                         al = SSL_AD_HANDSHAKE_FAILURE;
3064                         }
3065         }
3066
3067  err:
3068 #endif
3069         switch (ret)
3070                 {
3071                 case SSL_TLSEXT_ERR_ALERT_FATAL:
3072                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
3073                         return -1;
3074
3075                 case SSL_TLSEXT_ERR_ALERT_WARNING:
3076                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
3077                         return 1; 
3078                                         
3079                 case SSL_TLSEXT_ERR_NOACK:
3080                         s->servername_done=0;
3081                         default:
3082                 return 1;
3083                 }
3084         }
3085
3086 int ssl_check_clienthello_tlsext_late(SSL *s)
3087         {
3088         int ret = SSL_TLSEXT_ERR_OK;
3089         int al;
3090
3091         /* If status request then ask callback what to do.
3092          * Note: this must be called after servername callbacks in case
3093          * the certificate has changed, and must be called after the cipher
3094          * has been chosen because this may influence which certificate is sent
3095          */
3096         if ((s->tlsext_status_type != -1) && s->ctx && s->ctx->tlsext_status_cb)
3097                 {
3098                 int r;
3099                 CERT_PKEY *certpkey;
3100                 certpkey = ssl_get_server_send_pkey(s);
3101                 /* If no certificate can't return certificate status */
3102                 if (certpkey == NULL)
3103                         {
3104                         s->tlsext_status_expected = 0;
3105                         return 1;
3106                         }
3107                 /* Set current certificate to one we will use so
3108                  * SSL_get_certificate et al can pick it up.
3109                  */
3110                 s->cert->key = certpkey;
3111                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3112                 switch (r)
3113                         {
3114                         /* We don't want to send a status request response */
3115                         case SSL_TLSEXT_ERR_NOACK:
3116                                 s->tlsext_status_expected = 0;
3117                                 break;
3118                         /* status request response should be sent */
3119                         case SSL_TLSEXT_ERR_OK:
3120                                 if (s->tlsext_ocsp_resp)
3121                                         s->tlsext_status_expected = 1;
3122                                 else
3123                                         s->tlsext_status_expected = 0;
3124                                 break;
3125                         /* something bad happened */
3126                         case SSL_TLSEXT_ERR_ALERT_FATAL:
3127                                 ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3128                                 al = SSL_AD_INTERNAL_ERROR;
3129                                 goto err;
3130                         }
3131                 }
3132         else
3133                 s->tlsext_status_expected = 0;
3134
3135  err:
3136         switch (ret)
3137                 {
3138                 case SSL_TLSEXT_ERR_ALERT_FATAL:
3139                         ssl3_send_alert(s, SSL3_AL_FATAL, al);
3140                         return -1;
3141
3142                 case SSL_TLSEXT_ERR_ALERT_WARNING:
3143                         ssl3_send_alert(s, SSL3_AL_WARNING, al);
3144                         return 1; 
3145
3146                 default:
3147                         return 1;
3148                 }
3149         }
3150
3151 int ssl_check_serverhello_tlsext(SSL *s)
3152         {
3153         int ret=SSL_TLSEXT_ERR_NOACK;
3154         int al = SSL_AD_UNRECOGNIZED_NAME;
3155
3156 #ifndef OPENSSL_NO_EC
3157         /* If we are client and using an elliptic curve cryptography cipher
3158          * suite, then if server returns an EC point formats lists extension
3159          * it must contain uncompressed.
3160          */
3161         unsigned long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3162         unsigned long alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3163         if ((s->tlsext_ecpointformatlist != NULL) && (s->tlsext_ecpointformatlist_length > 0) && 
3164             (s->session->tlsext_ecpointformatlist != NULL) && (s->session->tlsext_ecpointformatlist_length > 0) && 
3165             ((alg_k & (SSL_kEECDH|SSL_kECDHr|SSL_kECDHe)) || (alg_a & SSL_aECDSA)))
3166                 {
3167                 /* we are using an ECC cipher */
3168                 size_t i;
3169                 unsigned char *list;
3170                 int found_uncompressed = 0;
3171                 list = s->session->tlsext_ecpointformatlist;
3172                 for (i = 0; i < s->session->tlsext_ecpointformatlist_length; i++)
3173                         {
3174                         if (*(list++) == TLSEXT_ECPOINTFORMAT_uncompressed)
3175                                 {
3176                                 found_uncompressed = 1;
3177                                 break;
3178                                 }
3179                         }
3180                 if (!found_uncompressed)
3181                         {
3182                         SSLerr(SSL_F_SSL_CHECK_SERVERHELLO_TLSEXT,SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST);
3183                         return -1;
3184                         }
3185                 }
3186         ret = SSL_TLSEXT_ERR_OK;
3187 #endif /* OPENSSL_NO_EC */
3188
3189         if (s->ctx != NULL && s->ctx->tlsext_servername_callback != 0) 
3190                 ret = s->ctx->tlsext_servername_callback(s, &al, s->ctx->tlsext_servername_arg);
3191         else if (s->initial_ctx != NULL && s->initial_ctx->tlsext_servername_callback != 0)             
3192                 ret = s->initial_ctx->tlsext_servername_callback(s, &al, s->initial_ctx->tlsext_servername_arg);
3193
3194 #ifdef TLSEXT_TYPE_opaque_prf_input
3195         if (s->s3->server_opaque_prf_input_len > 0)
3196                 {
3197                 /* This case may indicate that we, as a client, want to insist on using opaque PRF inputs.
3198                  * So first verify that we really have a value from the server too. */
3199
3200                 if (s->s3->server_opaque_prf_input == NULL)
3201                         {
3202                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3203                         al = SSL_AD_HANDSHAKE_FAILURE;
3204                         }
3205                 
3206                 /* Anytime the server *has* sent an opaque PRF input, we need to check
3207                  * that we have a client opaque PRF input of the same size. */
3208                 if (s->s3->client_opaque_prf_input == NULL ||
3209                     s->s3->client_opaque_prf_input_len != s->s3->server_opaque_prf_input_len)
3210                         {
3211                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3212                         al = SSL_AD_ILLEGAL_PARAMETER;
3213                         }
3214                 }
3215 #endif
3216
3217         /* If we've requested certificate status and we wont get one
3218          * tell the callback
3219          */
3220         if ((s->tlsext_status_type != -1) && !(s->tlsext_status_expected)
3221                         && s->ctx && s->ctx->tlsext_status_cb)
3222                 {
3223                 int r;
3224                 /* Set resp to NULL, resplen to -1 so callback knows
3225                  * there is no response.
3226                  */
3227                 if (s->tlsext_ocsp_resp)
3228                         {
3229                         OPENSSL_free(s->tlsext_ocsp_resp);
3230                         s->tlsext_ocsp_resp = NULL;
3231                         }
3232                 s->tlsext_ocsp_resplen = -1;
3233                 r = s->ctx->tlsext_status_cb(s, s->ctx->tlsext_status_arg);
3234                 if (r == 0)
3235                         {
3236                         al = SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE;
3237                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3238                         }
3239                 if (r < 0)
3240                         {
3241                         al = SSL_AD_INTERNAL_ERROR;
3242                         ret = SSL_TLSEXT_ERR_ALERT_FATAL;
3243                         }
3244                 }
3245
3246         switch (ret)
3247                 {
3248                 case SSL_TLSEXT_ERR_ALERT_FATAL:
3249                         ssl3_send_alert(s,SSL3_AL_FATAL,al); 
3250                         return -1;
3251
3252                 case SSL_TLSEXT_ERR_ALERT_WARNING:
3253                         ssl3_send_alert(s,SSL3_AL_WARNING,al);
3254                         return 1; 
3255                                         
3256                 case SSL_TLSEXT_ERR_NOACK:
3257                         s->servername_done=0;
3258                         default:
3259                 return 1;
3260                 }
3261         }
3262
3263 int ssl_parse_serverhello_tlsext(SSL *s, unsigned char **p, unsigned char *d, int n) 
3264         {
3265         int al = -1;
3266         if (s->version < SSL3_VERSION)
3267                 return 1;
3268         if (ssl_scan_serverhello_tlsext(s, p, d, n, &al) <= 0) 
3269                 {
3270                 ssl3_send_alert(s,SSL3_AL_FATAL,al); 
3271                 return 0;
3272                 }
3273
3274         if (ssl_check_serverhello_tlsext(s) <= 0) 
3275                 {
3276                 SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_TLSEXT,SSL_R_SERVERHELLO_TLSEXT);
3277                 return 0;
3278                 }
3279         return 1;
3280 }
3281
3282 /* Since the server cache lookup is done early on in the processing of the
3283  * ClientHello, and other operations depend on the result, we need to handle
3284  * any TLS session ticket extension at the same time.
3285  *
3286  *   session_id: points at the session ID in the ClientHello. This code will
3287  *       read past the end of this in order to parse out the session ticket
3288  *       extension, if any.
3289  *   len: the length of the session ID.
3290  *   limit: a pointer to the first byte after the ClientHello.
3291  *   ret: (output) on return, if a ticket was decrypted, then this is set to
3292  *       point to the resulting session.
3293  *
3294  * If s->tls_session_secret_cb is set then we are expecting a pre-shared key
3295  * ciphersuite, in which case we have no use for session tickets and one will
3296  * never be decrypted, nor will s->tlsext_ticket_expected be set to 1.
3297  *
3298  * Returns:
3299  *   -1: fatal error, either from parsing or decrypting the ticket.
3300  *    0: no ticket was found (or was ignored, based on settings).
3301  *    1: a zero length extension was found, indicating that the client supports
3302  *       session tickets but doesn't currently have one to offer.
3303  *    2: either s->tls_session_secret_cb was set, or a ticket was offered but
3304  *       couldn't be decrypted because of a non-fatal error.
3305  *    3: a ticket was successfully decrypted and *ret was set.
3306  *
3307  * Side effects:
3308  *   Sets s->tlsext_ticket_expected to 1 if the server will have to issue
3309  *   a new session ticket to the client because the client indicated support
3310  *   (and s->tls_session_secret_cb is NULL) but the client either doesn't have
3311  *   a session ticket or we couldn't use the one it gave us, or if
3312  *   s->ctx->tlsext_ticket_key_cb asked to renew the client's ticket.
3313  *   Otherwise, s->tlsext_ticket_expected is set to 0.
3314  */
3315 int tls1_process_ticket(SSL *s, unsigned char *session_id, int len,
3316                         const unsigned char *limit, SSL_SESSION **ret)
3317         {
3318         /* Point after session ID in client hello */
3319         const unsigned char *p = session_id + len;
3320         unsigned short i;
3321
3322         *ret = NULL;
3323         s->tlsext_ticket_expected = 0;
3324
3325         /* If tickets disabled behave as if no ticket present
3326          * to permit stateful resumption.
3327          */
3328         if (SSL_get_options(s) & SSL_OP_NO_TICKET)
3329                 return 0;
3330         if ((s->version <= SSL3_VERSION) || !limit)
3331                 return 0;
3332         if (p >= limit)
3333                 return -1;
3334         /* Skip past DTLS cookie */
3335         if (SSL_IS_DTLS(s))
3336                 {
3337                 i = *(p++);
3338                 p+= i;
3339                 if (p >= limit)
3340                         return -1;
3341                 }
3342         /* Skip past cipher list */
3343         n2s(p, i);
3344         p+= i;
3345         if (p >= limit)
3346                 return -1;
3347         /* Skip past compression algorithm list */
3348         i = *(p++);
3349         p += i;
3350         if (p > limit)
3351                 return -1;
3352         /* Now at start of extensions */
3353         if ((p + 2) >= limit)
3354                 return 0;
3355         n2s(p, i);
3356         while ((p + 4) <= limit)
3357                 {
3358                 unsigned short type, size;
3359                 n2s(p, type);
3360                 n2s(p, size);
3361                 if (p + size > limit)
3362                         return 0;
3363                 if (type == TLSEXT_TYPE_session_ticket)
3364                         {
3365                         int r;
3366                         if (size == 0)
3367                                 {
3368                                 /* The client will accept a ticket but doesn't
3369                                  * currently have one. */
3370                                 s->tlsext_ticket_expected = 1;
3371                                 return 1;
3372                                 }
3373                         if (s->tls_session_secret_cb)
3374                                 {
3375                                 /* Indicate that the ticket couldn't be
3376                                  * decrypted rather than generating the session
3377                                  * from ticket now, trigger abbreviated
3378                                  * handshake based on external mechanism to
3379                                  * calculate the master secret later. */
3380                                 return 2;
3381                                 }
3382                         r = tls_decrypt_ticket(s, p, size, session_id, len, ret);
3383                         switch (r)
3384                                 {
3385                                 case 2: /* ticket couldn't be decrypted */
3386                                         s->tlsext_ticket_expected = 1;
3387                                         return 2;
3388                                 case 3: /* ticket was decrypted */
3389                                         return r;
3390                                 case 4: /* ticket decrypted but need to renew */
3391                                         s->tlsext_ticket_expected = 1;
3392                                         return 3;
3393                                 default: /* fatal error */
3394                                         return -1;
3395                                 }
3396                         }
3397                 p += size;
3398                 }
3399         return 0;
3400         }
3401
3402 /* tls_decrypt_ticket attempts to decrypt a session ticket.
3403  *
3404  *   etick: points to the body of the session ticket extension.
3405  *   eticklen: the length of the session tickets extenion.
3406  *   sess_id: points at the session ID.
3407  *   sesslen: the length of the session ID.
3408  *   psess: (output) on return, if a ticket was decrypted, then this is set to
3409  *       point to the resulting session.
3410  *
3411  * Returns:
3412  *   -1: fatal error, either from parsing or decrypting the ticket.
3413  *    2: the ticket couldn't be decrypted.
3414  *    3: a ticket was successfully decrypted and *psess was set.
3415  *    4: same as 3, but the ticket needs to be renewed.
3416  */
3417 static int tls_decrypt_ticket(SSL *s, const unsigned char *etick, int eticklen,
3418                                 const unsigned char *sess_id, int sesslen,
3419                                 SSL_SESSION **psess)
3420         {
3421         SSL_SESSION *sess;
3422         unsigned char *sdec;
3423         const unsigned char *p;
3424         int slen, mlen, renew_ticket = 0;
3425         unsigned char tick_hmac[EVP_MAX_MD_SIZE];
3426         HMAC_CTX hctx;
3427         EVP_CIPHER_CTX ctx;
3428         SSL_CTX *tctx = s->initial_ctx;
3429         /* Need at least keyname + iv + some encrypted data */
3430         if (eticklen < 48)
3431                 return 2;
3432         /* Initialize session ticket encryption and HMAC contexts */
3433         HMAC_CTX_init(&hctx);
3434         EVP_CIPHER_CTX_init(&ctx);
3435         if (tctx->tlsext_ticket_key_cb)
3436                 {
3437                 unsigned char *nctick = (unsigned char *)etick;
3438                 int rv = tctx->tlsext_ticket_key_cb(s, nctick, nctick + 16,
3439                                                         &ctx, &hctx, 0);
3440                 if (rv < 0)
3441                         return -1;
3442                 if (rv == 0)
3443                         return 2;
3444                 if (rv == 2)
3445                         renew_ticket = 1;
3446                 }
3447         else
3448                 {
3449                 /* Check key name matches */
3450                 if (memcmp(etick, tctx->tlsext_tick_key_name, 16))
3451                         return 2;
3452                 HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16,
3453                                         tlsext_tick_md(), NULL);
3454                 EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
3455                                 tctx->tlsext_tick_aes_key, etick + 16);
3456                 }