1 /* ssl/s23_clnt.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) 1998-2006 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 "ssl_locl.h"
114 #include <openssl/buffer.h>
115 #include <openssl/rand.h>
116 #include <openssl/objects.h>
117 #include <openssl/evp.h>
118 
119 static const SSL_METHOD *ssl23_get_client_method(int ver);
120 static int ssl23_client_hello(SSL *s);
121 static int ssl23_get_server_hello(SSL *s);
ssl23_get_client_method(int ver)122 static const SSL_METHOD *ssl23_get_client_method(int ver)
123 {
124 #ifndef OPENSSL_NO_SSL2
125     if (ver == SSL2_VERSION)
126         return (SSLv2_client_method());
127 #endif
128 #ifndef OPENSSL_NO_SSL3
129     if (ver == SSL3_VERSION)
130         return (SSLv3_client_method());
131 #endif
132     if (ver == TLS1_VERSION)
133         return (TLSv1_client_method());
134     else if (ver == TLS1_1_VERSION)
135         return (TLSv1_1_client_method());
136     else if (ver == TLS1_2_VERSION)
137         return (TLSv1_2_client_method());
138     else
139         return (NULL);
140 }
141 
IMPLEMENT_ssl23_meth_func(SSLv23_client_method,ssl_undefined_function,ssl23_connect,ssl23_get_client_method)142 IMPLEMENT_ssl23_meth_func(SSLv23_client_method,
143                           ssl_undefined_function,
144                           ssl23_connect, ssl23_get_client_method)
145 
146 int ssl23_connect(SSL *s)
147 {
148     BUF_MEM *buf = NULL;
149     unsigned long Time = (unsigned long)time(NULL);
150     void (*cb) (const SSL *ssl, int type, int val) = NULL;
151     int ret = -1;
152     int new_state, state;
153 
154     RAND_add(&Time, sizeof(Time), 0);
155     ERR_clear_error();
156     clear_sys_error();
157 
158     if (s->info_callback != NULL)
159         cb = s->info_callback;
160     else if (s->ctx->info_callback != NULL)
161         cb = s->ctx->info_callback;
162 
163     s->in_handshake++;
164     if (!SSL_in_init(s) || SSL_in_before(s))
165         SSL_clear(s);
166 
167     for (;;) {
168         state = s->state;
169 
170         switch (s->state) {
171         case SSL_ST_BEFORE:
172         case SSL_ST_CONNECT:
173         case SSL_ST_BEFORE | SSL_ST_CONNECT:
174         case SSL_ST_OK | SSL_ST_CONNECT:
175 
176             if (s->session != NULL) {
177                 SSLerr(SSL_F_SSL23_CONNECT,
178                        SSL_R_SSL23_DOING_SESSION_ID_REUSE);
179                 ret = -1;
180                 goto end;
181             }
182             s->server = 0;
183             if (cb != NULL)
184                 cb(s, SSL_CB_HANDSHAKE_START, 1);
185 
186             /* s->version=TLS1_VERSION; */
187             s->type = SSL_ST_CONNECT;
188 
189             if (s->init_buf == NULL) {
190                 if ((buf = BUF_MEM_new()) == NULL) {
191                     ret = -1;
192                     goto end;
193                 }
194                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
195                     ret = -1;
196                     goto end;
197                 }
198                 s->init_buf = buf;
199                 buf = NULL;
200             }
201 
202             if (!ssl3_setup_buffers(s)) {
203                 ret = -1;
204                 goto end;
205             }
206 
207             if (!ssl3_init_finished_mac(s)) {
208                 ret = -1;
209                 goto end;
210             }
211 
212             s->state = SSL23_ST_CW_CLNT_HELLO_A;
213             s->ctx->stats.sess_connect++;
214             s->init_num = 0;
215             break;
216 
217         case SSL23_ST_CW_CLNT_HELLO_A:
218         case SSL23_ST_CW_CLNT_HELLO_B:
219 
220             s->shutdown = 0;
221             ret = ssl23_client_hello(s);
222             if (ret <= 0)
223                 goto end;
224             s->state = SSL23_ST_CR_SRVR_HELLO_A;
225             s->init_num = 0;
226 
227             break;
228 
229         case SSL23_ST_CR_SRVR_HELLO_A:
230         case SSL23_ST_CR_SRVR_HELLO_B:
231             ret = ssl23_get_server_hello(s);
232             if (ret >= 0)
233                 cb = NULL;
234             goto end;
235             /* break; */
236 
237         default:
238             SSLerr(SSL_F_SSL23_CONNECT, SSL_R_UNKNOWN_STATE);
239             ret = -1;
240             goto end;
241             /* break; */
242         }
243 
244         if (s->debug) {
245             (void)BIO_flush(s->wbio);
246         }
247 
248         if ((cb != NULL) && (s->state != state)) {
249             new_state = s->state;
250             s->state = state;
251             cb(s, SSL_CB_CONNECT_LOOP, 1);
252             s->state = new_state;
253         }
254     }
255  end:
256     s->in_handshake--;
257     if (buf != NULL)
258         BUF_MEM_free(buf);
259     if (cb != NULL)
260         cb(s, SSL_CB_CONNECT_EXIT, ret);
261     return (ret);
262 }
263 
ssl23_no_ssl2_ciphers(SSL * s)264 static int ssl23_no_ssl2_ciphers(SSL *s)
265 {
266     SSL_CIPHER *cipher;
267     STACK_OF(SSL_CIPHER) *ciphers;
268     int i;
269     ciphers = SSL_get_ciphers(s);
270     for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++) {
271         cipher = sk_SSL_CIPHER_value(ciphers, i);
272         if (cipher->algorithm_ssl == SSL_SSLV2)
273             return 0;
274     }
275     return 1;
276 }
277 
278 /*
279  * Fill a ClientRandom or ServerRandom field of length len. Returns <= 0 on
280  * failure, 1 on success.
281  */
ssl_fill_hello_random(SSL * s,int server,unsigned char * result,int len)282 int ssl_fill_hello_random(SSL *s, int server, unsigned char *result, int len)
283 {
284     int send_time = 0;
285     if (len < 4)
286         return 0;
287     if (server)
288         send_time = (s->mode & SSL_MODE_SEND_SERVERHELLO_TIME) != 0;
289     else
290         send_time = (s->mode & SSL_MODE_SEND_CLIENTHELLO_TIME) != 0;
291     if (send_time) {
292         unsigned long Time = (unsigned long)time(NULL);
293         unsigned char *p = result;
294         l2n(Time, p);
295         return RAND_bytes(p, len - 4);
296     } else
297         return RAND_bytes(result, len);
298 }
299 
ssl23_client_hello(SSL * s)300 static int ssl23_client_hello(SSL *s)
301 {
302     unsigned char *buf;
303     unsigned char *p, *d;
304     int i, ch_len;
305     unsigned long l;
306     int ssl2_compat;
307     int version = 0, version_major, version_minor;
308     int al = 0;
309 #ifndef OPENSSL_NO_COMP
310     int j;
311     SSL_COMP *comp;
312 #endif
313     int ret;
314     unsigned long mask, options = s->options;
315 
316     ssl2_compat = (options & SSL_OP_NO_SSLv2) ? 0 : 1;
317 
318     if (ssl2_compat && ssl23_no_ssl2_ciphers(s))
319         ssl2_compat = 0;
320 
321     /*
322      * SSL_OP_NO_X disables all protocols above X *if* there are
323      * some protocols below X enabled. This is required in order
324      * to maintain "version capability" vector contiguous. So
325      * that if application wants to disable TLS1.0 in favour of
326      * TLS1>=1, it would be insufficient to pass SSL_NO_TLSv1, the
327      * answer is SSL_OP_NO_TLSv1|SSL_OP_NO_SSLv3|SSL_OP_NO_SSLv2.
328      */
329     mask = SSL_OP_NO_TLSv1_1 | SSL_OP_NO_TLSv1
330 #if !defined(OPENSSL_NO_SSL3)
331         | SSL_OP_NO_SSLv3
332 #endif
333 #if !defined(OPENSSL_NO_SSL2)
334         | (ssl2_compat ? SSL_OP_NO_SSLv2 : 0)
335 #endif
336         ;
337 #if !defined(OPENSSL_NO_TLS1_2_CLIENT)
338     version = TLS1_2_VERSION;
339 
340     if ((options & SSL_OP_NO_TLSv1_2) && (options & mask) != mask)
341         version = TLS1_1_VERSION;
342 #else
343     version = TLS1_1_VERSION;
344 #endif
345     mask &= ~SSL_OP_NO_TLSv1_1;
346     if ((options & SSL_OP_NO_TLSv1_1) && (options & mask) != mask)
347         version = TLS1_VERSION;
348     mask &= ~SSL_OP_NO_TLSv1;
349 #if !defined(OPENSSL_NO_SSL3)
350     if ((options & SSL_OP_NO_TLSv1) && (options & mask) != mask)
351         version = SSL3_VERSION;
352     mask &= ~SSL_OP_NO_SSLv3;
353 #endif
354 #if !defined(OPENSSL_NO_SSL2)
355     if ((options & SSL_OP_NO_SSLv3) && (options & mask) != mask)
356         version = SSL2_VERSION;
357 #endif
358 
359 #ifndef OPENSSL_NO_TLSEXT
360     if (version != SSL2_VERSION) {
361         /*
362          * have to disable SSL 2.0 compatibility if we need TLS extensions
363          */
364 
365         if (s->tlsext_hostname != NULL)
366             ssl2_compat = 0;
367         if (s->tlsext_status_type != -1)
368             ssl2_compat = 0;
369 # ifdef TLSEXT_TYPE_opaque_prf_input
370         if (s->ctx->tlsext_opaque_prf_input_callback != 0
371             || s->tlsext_opaque_prf_input != NULL)
372             ssl2_compat = 0;
373 # endif
374         if (s->cert->cli_ext.meths_count != 0)
375             ssl2_compat = 0;
376     }
377 #endif
378 
379     buf = (unsigned char *)s->init_buf->data;
380     if (s->state == SSL23_ST_CW_CLNT_HELLO_A) {
381         /*
382          * Since we're sending s23 client hello, we're not reusing a session, as
383          * we'd be using the method from the saved session instead
384          */
385         if (!ssl_get_new_session(s, 0)) {
386             return -1;
387         }
388 
389         p = s->s3->client_random;
390         if (ssl_fill_hello_random(s, 0, p, SSL3_RANDOM_SIZE) <= 0)
391             return -1;
392 
393         if (version == TLS1_2_VERSION) {
394             version_major = TLS1_2_VERSION_MAJOR;
395             version_minor = TLS1_2_VERSION_MINOR;
396         } else if (tls1_suiteb(s)) {
397             SSLerr(SSL_F_SSL23_CLIENT_HELLO,
398                    SSL_R_ONLY_TLS_1_2_ALLOWED_IN_SUITEB_MODE);
399             return -1;
400         } else if (version == TLS1_1_VERSION) {
401             version_major = TLS1_1_VERSION_MAJOR;
402             version_minor = TLS1_1_VERSION_MINOR;
403         } else if (version == TLS1_VERSION) {
404             version_major = TLS1_VERSION_MAJOR;
405             version_minor = TLS1_VERSION_MINOR;
406         }
407 #ifdef OPENSSL_FIPS
408         else if (FIPS_mode()) {
409             SSLerr(SSL_F_SSL23_CLIENT_HELLO,
410                    SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
411             return -1;
412         }
413 #endif
414         else if (version == SSL3_VERSION) {
415             version_major = SSL3_VERSION_MAJOR;
416             version_minor = SSL3_VERSION_MINOR;
417         } else if (version == SSL2_VERSION) {
418             version_major = SSL2_VERSION_MAJOR;
419             version_minor = SSL2_VERSION_MINOR;
420         } else {
421             SSLerr(SSL_F_SSL23_CLIENT_HELLO, SSL_R_NO_PROTOCOLS_AVAILABLE);
422             return (-1);
423         }
424 
425         s->client_version = version;
426 
427         if (ssl2_compat) {
428             /* create SSL 2.0 compatible Client Hello */
429 
430             /* two byte record header will be written last */
431             d = &(buf[2]);
432             p = d + 9;          /* leave space for message type, version,
433                                  * individual length fields */
434 
435             *(d++) = SSL2_MT_CLIENT_HELLO;
436             *(d++) = version_major;
437             *(d++) = version_minor;
438 
439             /* Ciphers supported */
440             i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), p, 0);
441             if (i == 0) {
442                 /* no ciphers */
443                 SSLerr(SSL_F_SSL23_CLIENT_HELLO, SSL_R_NO_CIPHERS_AVAILABLE);
444                 return -1;
445             }
446             s2n(i, d);
447             p += i;
448 
449             /*
450              * put in the session-id length (zero since there is no reuse)
451              */
452             s2n(0, d);
453 
454             if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
455                 ch_len = SSL2_CHALLENGE_LENGTH;
456             else
457                 ch_len = SSL2_MAX_CHALLENGE_LENGTH;
458 
459             /* write out sslv2 challenge */
460             /*
461              * Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because it
462              * is one of SSL2_MAX_CHALLENGE_LENGTH (32) or
463              * SSL2_MAX_CHALLENGE_LENGTH (16), but leave the check in for
464              * futurproofing
465              */
466             if (SSL3_RANDOM_SIZE < ch_len)
467                 i = SSL3_RANDOM_SIZE;
468             else
469                 i = ch_len;
470             s2n(i, d);
471             memset(&(s->s3->client_random[0]), 0, SSL3_RANDOM_SIZE);
472             if (RAND_bytes (&(s->s3->client_random[SSL3_RANDOM_SIZE - i]), i)
473                     <= 0)
474                 return -1;
475 
476             memcpy(p, &(s->s3->client_random[SSL3_RANDOM_SIZE - i]), i);
477             p += i;
478 
479             i = p - &(buf[2]);
480             buf[0] = ((i >> 8) & 0xff) | 0x80;
481             buf[1] = (i & 0xff);
482 
483             /* number of bytes to write */
484             s->init_num = i + 2;
485             s->init_off = 0;
486 
487             ssl3_finish_mac(s, &(buf[2]), i);
488         } else {
489             /* create Client Hello in SSL 3.0/TLS 1.0 format */
490 
491             /*
492              * do the record header (5 bytes) and handshake message header (4
493              * bytes) last
494              */
495             d = p = &(buf[9]);
496 
497             *(p++) = version_major;
498             *(p++) = version_minor;
499 
500             /* Random stuff */
501             memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
502             p += SSL3_RANDOM_SIZE;
503 
504             /* Session ID (zero since there is no reuse) */
505             *(p++) = 0;
506 
507             /* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
508             i = ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), &(p[2]),
509                                          ssl3_put_cipher_by_char);
510             if (i == 0) {
511                 SSLerr(SSL_F_SSL23_CLIENT_HELLO, SSL_R_NO_CIPHERS_AVAILABLE);
512                 return -1;
513             }
514 #ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
515             /*
516              * Some servers hang if client hello > 256 bytes as hack
517              * workaround chop number of supported ciphers to keep it well
518              * below this if we use TLS v1.2
519              */
520             if (TLS1_get_version(s) >= TLS1_2_VERSION
521                 && i > OPENSSL_MAX_TLS1_2_CIPHER_LENGTH)
522                 i = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
523 #endif
524             s2n(i, p);
525             p += i;
526 
527             /* COMPRESSION */
528 #ifdef OPENSSL_NO_COMP
529             *(p++) = 1;
530 #else
531             if ((s->options & SSL_OP_NO_COMPRESSION)
532                 || !s->ctx->comp_methods)
533                 j = 0;
534             else
535                 j = sk_SSL_COMP_num(s->ctx->comp_methods);
536             *(p++) = 1 + j;
537             for (i = 0; i < j; i++) {
538                 comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
539                 *(p++) = comp->id;
540             }
541 #endif
542             *(p++) = 0;         /* Add the NULL method */
543 
544 #ifndef OPENSSL_NO_TLSEXT
545             /* TLS extensions */
546             if (ssl_prepare_clienthello_tlsext(s) <= 0) {
547                 SSLerr(SSL_F_SSL23_CLIENT_HELLO, SSL_R_CLIENTHELLO_TLSEXT);
548                 return -1;
549             }
550             if ((p =
551                  ssl_add_clienthello_tlsext(s, p,
552                                             buf + SSL3_RT_MAX_PLAIN_LENGTH,
553                                             &al)) == NULL) {
554                 ssl3_send_alert(s, SSL3_AL_FATAL, al);
555                 SSLerr(SSL_F_SSL23_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
556                 return -1;
557             }
558 #endif
559 
560             l = p - d;
561 
562             /* fill in 4-byte handshake header */
563             d = &(buf[5]);
564             *(d++) = SSL3_MT_CLIENT_HELLO;
565             l2n3(l, d);
566 
567             l += 4;
568 
569             if (l > SSL3_RT_MAX_PLAIN_LENGTH) {
570                 SSLerr(SSL_F_SSL23_CLIENT_HELLO, ERR_R_INTERNAL_ERROR);
571                 return -1;
572             }
573 
574             /* fill in 5-byte record header */
575             d = buf;
576             *(d++) = SSL3_RT_HANDSHAKE;
577             *(d++) = version_major;
578             /*
579              * Some servers hang if we use long client hellos and a record
580              * number > TLS 1.0.
581              */
582             if (TLS1_get_client_version(s) > TLS1_VERSION)
583                 *(d++) = 1;
584             else
585                 *(d++) = version_minor;
586             s2n((int)l, d);
587 
588             /* number of bytes to write */
589             s->init_num = p - buf;
590             s->init_off = 0;
591 
592             ssl3_finish_mac(s, &(buf[5]), s->init_num - 5);
593         }
594 
595         s->state = SSL23_ST_CW_CLNT_HELLO_B;
596         s->init_off = 0;
597     }
598 
599     /* SSL3_ST_CW_CLNT_HELLO_B */
600     ret = ssl23_write_bytes(s);
601 
602     if ((ret >= 2) && s->msg_callback) {
603         /* Client Hello has been sent; tell msg_callback */
604 
605         if (ssl2_compat)
606             s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data + 2,
607                             ret - 2, s, s->msg_callback_arg);
608         else {
609             s->msg_callback(1, version, SSL3_RT_HEADER, s->init_buf->data, 5,
610                             s, s->msg_callback_arg);
611             s->msg_callback(1, version, SSL3_RT_HANDSHAKE,
612                             s->init_buf->data + 5, ret - 5, s,
613                             s->msg_callback_arg);
614         }
615     }
616 
617     return ret;
618 }
619 
ssl23_get_server_hello(SSL * s)620 static int ssl23_get_server_hello(SSL *s)
621 {
622     char buf[8];
623     unsigned char *p;
624     int i;
625     int n;
626 
627     n = ssl23_read_bytes(s, 7);
628 
629     if (n != 7)
630         return (n);
631     p = s->packet;
632 
633     memcpy(buf, p, n);
634 
635     if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
636         (p[5] == 0x00) && (p[6] == 0x02)) {
637 #ifdef OPENSSL_NO_SSL2
638         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
639         goto err;
640 #else
641         /* we are talking sslv2 */
642         /*
643          * we need to clean up the SSLv3 setup and put in the sslv2 stuff.
644          */
645         int ch_len;
646 
647         if (s->options & SSL_OP_NO_SSLv2) {
648             SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
649             goto err;
650         }
651         if (s->s2 == NULL) {
652             if (!ssl2_new(s))
653                 goto err;
654         } else
655             ssl2_clear(s);
656 
657         if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
658             ch_len = SSL2_CHALLENGE_LENGTH;
659         else
660             ch_len = SSL2_MAX_CHALLENGE_LENGTH;
661 
662         /* write out sslv2 challenge */
663         /*
664          * Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because it is
665          * one of SSL2_MAX_CHALLENGE_LENGTH (32) or SSL2_MAX_CHALLENGE_LENGTH
666          * (16), but leave the check in for futurproofing
667          */
668         i = (SSL3_RANDOM_SIZE < ch_len)
669             ? SSL3_RANDOM_SIZE : ch_len;
670         s->s2->challenge_length = i;
671         memcpy(s->s2->challenge,
672                &(s->s3->client_random[SSL3_RANDOM_SIZE - i]), i);
673 
674         if (s->s3 != NULL)
675             ssl3_free(s);
676 
677         if (!BUF_MEM_grow_clean(s->init_buf,
678                                 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) {
679             SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, ERR_R_BUF_LIB);
680             goto err;
681         }
682 
683         s->state = SSL2_ST_GET_SERVER_HELLO_A;
684         if (!(s->client_version == SSL2_VERSION))
685             /*
686              * use special padding (SSL 3.0 draft/RFC 2246, App. E.2)
687              */
688             s->s2->ssl2_rollback = 1;
689 
690         /*
691          * setup the 7 bytes we have read so we get them from the sslv2
692          * buffer
693          */
694         s->rstate = SSL_ST_READ_HEADER;
695         s->packet_length = n;
696         s->packet = &(s->s2->rbuf[0]);
697         memcpy(s->packet, buf, n);
698         s->s2->rbuf_left = n;
699         s->s2->rbuf_offs = 0;
700 
701         /* we have already written one */
702         s->s2->write_sequence = 1;
703 
704         s->method = SSLv2_client_method();
705         s->handshake_func = s->method->ssl_connect;
706 #endif
707     } else if (p[1] == SSL3_VERSION_MAJOR &&
708                p[2] <= TLS1_2_VERSION_MINOR &&
709                ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
710                 (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2))) {
711         /* we have sslv3 or tls1 (server hello or alert) */
712 
713 #ifndef OPENSSL_NO_SSL3
714         if ((p[2] == SSL3_VERSION_MINOR) && !(s->options & SSL_OP_NO_SSLv3)) {
715 # ifdef OPENSSL_FIPS
716             if (FIPS_mode()) {
717                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,
718                        SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
719                 goto err;
720             }
721 # endif
722             s->version = SSL3_VERSION;
723             s->method = SSLv3_client_method();
724         } else
725 #endif
726         if ((p[2] == TLS1_VERSION_MINOR) && !(s->options & SSL_OP_NO_TLSv1)) {
727             s->version = TLS1_VERSION;
728             s->method = TLSv1_client_method();
729         } else if ((p[2] == TLS1_1_VERSION_MINOR) &&
730                    !(s->options & SSL_OP_NO_TLSv1_1)) {
731             s->version = TLS1_1_VERSION;
732             s->method = TLSv1_1_client_method();
733         } else if ((p[2] == TLS1_2_VERSION_MINOR) &&
734                    !(s->options & SSL_OP_NO_TLSv1_2)) {
735             s->version = TLS1_2_VERSION;
736             s->method = TLSv1_2_client_method();
737         } else {
738             /*
739              * Unrecognised version, we'll send a protocol version alert using
740              * our preferred version.
741              */
742             switch(s->client_version) {
743             default:
744                 /*
745                  * Shouldn't happen
746                  * Fall through
747                  */
748             case TLS1_2_VERSION:
749                 s->version = TLS1_2_VERSION;
750                 s->method = TLSv1_2_client_method();
751                 break;
752             case TLS1_1_VERSION:
753                 s->version = TLS1_1_VERSION;
754                 s->method = TLSv1_1_client_method();
755                 break;
756             case TLS1_VERSION:
757                 s->version = TLS1_VERSION;
758                 s->method = TLSv1_client_method();
759                 break;
760 #ifndef OPENSSL_NO_SSL3
761             case SSL3_VERSION:
762                 s->version = SSL3_VERSION;
763                 s->method = SSLv3_client_method();
764                 break;
765 #endif
766             }
767             SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
768             ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION);
769             goto err;
770         }
771 
772         s->session->ssl_version = s->version;
773 
774         /* ensure that TLS_MAX_VERSION is up-to-date */
775         OPENSSL_assert(s->version <= TLS_MAX_VERSION);
776 
777         if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING) {
778             /* fatal alert */
779 
780             void (*cb) (const SSL *ssl, int type, int val) = NULL;
781             int j;
782 
783             if (s->info_callback != NULL)
784                 cb = s->info_callback;
785             else if (s->ctx->info_callback != NULL)
786                 cb = s->ctx->info_callback;
787 
788             i = p[5];
789             if (cb != NULL) {
790                 j = (i << 8) | p[6];
791                 cb(s, SSL_CB_READ_ALERT, j);
792             }
793 
794             if (s->msg_callback) {
795                 s->msg_callback(0, s->version, SSL3_RT_HEADER, p, 5, s,
796                                 s->msg_callback_arg);
797                 s->msg_callback(0, s->version, SSL3_RT_ALERT, p + 5, 2, s,
798                                 s->msg_callback_arg);
799             }
800 
801             s->rwstate = SSL_NOTHING;
802             SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_AD_REASON_OFFSET + p[6]);
803             goto err;
804         }
805 
806         if (!ssl_init_wbio_buffer(s, 1))
807             goto err;
808 
809         /* we are in this state */
810         s->state = SSL3_ST_CR_SRVR_HELLO_A;
811 
812         /*
813          * put the 7 bytes we have read into the input buffer for SSLv3
814          */
815         s->rstate = SSL_ST_READ_HEADER;
816         s->packet_length = n;
817         if (s->s3->rbuf.buf == NULL)
818             if (!ssl3_setup_read_buffer(s))
819                 goto err;
820         s->packet = &(s->s3->rbuf.buf[0]);
821         memcpy(s->packet, buf, n);
822         s->s3->rbuf.left = n;
823         s->s3->rbuf.offset = 0;
824 
825         s->handshake_func = s->method->ssl_connect;
826     } else {
827         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO, SSL_R_UNKNOWN_PROTOCOL);
828         goto err;
829     }
830     s->init_num = 0;
831 
832     return (SSL_connect(s));
833  err:
834     return (-1);
835 }
836