1 /* $OpenBSD: ssl_pkt.c,v 1.66 2023/07/11 17:02:47 tb Exp $ */
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) 1998-2002 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 <errno.h>
113 #include <limits.h>
114 #include <stdio.h>
115
116 #include <openssl/buffer.h>
117 #include <openssl/evp.h>
118
119 #include "bytestring.h"
120 #include "dtls_local.h"
121 #include "ssl_local.h"
122 #include "tls_content.h"
123
124 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
125 unsigned int len);
126 static int ssl3_get_record(SSL *s);
127
128 /*
129 * Force a WANT_READ return for certain error conditions where
130 * we don't want to spin internally.
131 */
132 void
ssl_force_want_read(SSL * s)133 ssl_force_want_read(SSL *s)
134 {
135 BIO *bio;
136
137 bio = SSL_get_rbio(s);
138 BIO_clear_retry_flags(bio);
139 BIO_set_retry_read(bio);
140
141 s->rwstate = SSL_READING;
142 }
143
144 /*
145 * If extend == 0, obtain new n-byte packet; if extend == 1, increase
146 * packet by another n bytes.
147 * The packet will be in the sub-array of s->s3->rbuf.buf specified
148 * by s->packet and s->packet_length.
149 * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
150 * [plus s->packet_length bytes if extend == 1].)
151 */
152 static int
ssl3_read_n(SSL * s,int n,int max,int extend)153 ssl3_read_n(SSL *s, int n, int max, int extend)
154 {
155 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf);
156 int i, len, left;
157 size_t align;
158 unsigned char *pkt;
159
160 if (n <= 0)
161 return n;
162
163 if (rb->buf == NULL) {
164 if (!ssl3_setup_read_buffer(s))
165 return -1;
166 }
167 if (rb->buf == NULL)
168 return -1;
169
170 left = rb->left;
171 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH;
172 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
173
174 if (!extend) {
175 /* start with empty packet ... */
176 if (left == 0)
177 rb->offset = align;
178 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) {
179 /* check if next packet length is large
180 * enough to justify payload alignment... */
181 pkt = rb->buf + rb->offset;
182 if (pkt[0] == SSL3_RT_APPLICATION_DATA &&
183 (pkt[3]<<8|pkt[4]) >= 128) {
184 /* Note that even if packet is corrupted
185 * and its length field is insane, we can
186 * only be led to wrong decision about
187 * whether memmove will occur or not.
188 * Header values has no effect on memmove
189 * arguments and therefore no buffer
190 * overrun can be triggered. */
191 memmove(rb->buf + align, pkt, left);
192 rb->offset = align;
193 }
194 }
195 s->packet = rb->buf + rb->offset;
196 s->packet_length = 0;
197 /* ... now we can act as if 'extend' was set */
198 }
199
200 /* For DTLS/UDP reads should not span multiple packets
201 * because the read operation returns the whole packet
202 * at once (as long as it fits into the buffer). */
203 if (SSL_is_dtls(s)) {
204 if (left > 0 && n > left)
205 n = left;
206 }
207
208 /* if there is enough in the buffer from a previous read, take some */
209 if (left >= n) {
210 s->packet_length += n;
211 rb->left = left - n;
212 rb->offset += n;
213 return (n);
214 }
215
216 /* else we need to read more data */
217
218 len = s->packet_length;
219 pkt = rb->buf + align;
220 /* Move any available bytes to front of buffer:
221 * 'len' bytes already pointed to by 'packet',
222 * 'left' extra ones at the end */
223 if (s->packet != pkt) {
224 /* len > 0 */
225 memmove(pkt, s->packet, len + left);
226 s->packet = pkt;
227 rb->offset = len + align;
228 }
229
230 if (n > (int)(rb->len - rb->offset)) {
231 /* does not happen */
232 SSLerror(s, ERR_R_INTERNAL_ERROR);
233 return -1;
234 }
235
236 if (s->read_ahead || SSL_is_dtls(s)) {
237 if (max < n)
238 max = n;
239 if (max > (int)(rb->len - rb->offset))
240 max = rb->len - rb->offset;
241 } else {
242 /* ignore max parameter */
243 max = n;
244 }
245
246 while (left < n) {
247 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
248 * and need to read in more until we have len+n (up to
249 * len+max if possible) */
250
251 errno = 0;
252 if (s->rbio != NULL) {
253 s->rwstate = SSL_READING;
254 i = BIO_read(s->rbio, pkt + len + left, max - left);
255 } else {
256 SSLerror(s, SSL_R_READ_BIO_NOT_SET);
257 i = -1;
258 }
259
260 if (i <= 0) {
261 rb->left = left;
262 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
263 !SSL_is_dtls(s)) {
264 if (len + left == 0)
265 ssl3_release_read_buffer(s);
266 }
267 return (i);
268 }
269 left += i;
270
271 /*
272 * reads should *never* span multiple packets for DTLS because
273 * the underlying transport protocol is message oriented as
274 * opposed to byte oriented as in the TLS case.
275 */
276 if (SSL_is_dtls(s)) {
277 if (n > left)
278 n = left; /* makes the while condition false */
279 }
280 }
281
282 /* done reading, now the book-keeping */
283 rb->offset += n;
284 rb->left = left - n;
285 s->packet_length += n;
286 s->rwstate = SSL_NOTHING;
287
288 return (n);
289 }
290
291 int
ssl3_packet_read(SSL * s,int plen)292 ssl3_packet_read(SSL *s, int plen)
293 {
294 int n;
295
296 n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0);
297 if (n <= 0)
298 return n;
299 if (s->packet_length < plen)
300 return s->packet_length;
301
302 return plen;
303 }
304
305 int
ssl3_packet_extend(SSL * s,int plen)306 ssl3_packet_extend(SSL *s, int plen)
307 {
308 int rlen, n;
309
310 if (s->packet_length >= plen)
311 return plen;
312 rlen = plen - s->packet_length;
313
314 n = ssl3_read_n(s, rlen, rlen, 1);
315 if (n <= 0)
316 return n;
317 if (s->packet_length < plen)
318 return s->packet_length;
319
320 return plen;
321 }
322
323 /* Call this to get a new input record.
324 * It will return <= 0 if more data is needed, normally due to an error
325 * or non-blocking IO.
326 * When it finishes, one packet has been decoded and can be found in
327 * ssl->s3->rrec.type - is the type of record
328 * ssl->s3->rrec.data, - data
329 * ssl->s3->rrec.length, - number of bytes
330 */
331 /* used only by ssl3_read_bytes */
332 static int
ssl3_get_record(SSL * s)333 ssl3_get_record(SSL *s)
334 {
335 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf);
336 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec);
337 uint8_t alert_desc;
338 int al, n;
339 int ret = -1;
340
341 again:
342 /* check if we have the header */
343 if ((s->rstate != SSL_ST_READ_BODY) ||
344 (s->packet_length < SSL3_RT_HEADER_LENGTH)) {
345 CBS header;
346 uint16_t len, ssl_version;
347 uint8_t type;
348
349 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH);
350 if (n <= 0)
351 return (n);
352
353 s->mac_packet = 1;
354 s->rstate = SSL_ST_READ_BODY;
355
356 if (s->server && s->first_packet) {
357 if ((ret = ssl_server_legacy_first_packet(s)) != 1)
358 return (ret);
359 ret = -1;
360 }
361
362 CBS_init(&header, s->packet, SSL3_RT_HEADER_LENGTH);
363
364 /* Pull apart the header into the SSL3_RECORD_INTERNAL */
365 if (!CBS_get_u8(&header, &type) ||
366 !CBS_get_u16(&header, &ssl_version) ||
367 !CBS_get_u16(&header, &len)) {
368 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
369 goto err;
370 }
371
372 rr->type = type;
373 rr->length = len;
374
375 /* Lets check version */
376 if (!s->first_packet && ssl_version != s->version) {
377 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) &&
378 !tls12_record_layer_write_protected(s->rl)) {
379 /* Send back error using their minor version number :-) */
380 s->version = ssl_version;
381 }
382 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
383 al = SSL_AD_PROTOCOL_VERSION;
384 goto fatal_err;
385 }
386
387 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) {
388 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
389 goto err;
390 }
391
392 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) {
393 al = SSL_AD_RECORD_OVERFLOW;
394 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG);
395 goto fatal_err;
396 }
397 }
398
399 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length);
400 if (n <= 0)
401 return (n);
402 if (n != SSL3_RT_HEADER_LENGTH + rr->length)
403 return (n);
404
405 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
406
407 /*
408 * A full record has now been read from the wire, which now needs
409 * to be processed.
410 */
411 tls12_record_layer_set_version(s->rl, s->version);
412
413 if (!tls12_record_layer_open_record(s->rl, s->packet, s->packet_length,
414 s->s3->rcontent)) {
415 tls12_record_layer_alert(s->rl, &alert_desc);
416
417 if (alert_desc == 0)
418 goto err;
419
420 if (alert_desc == SSL_AD_RECORD_OVERFLOW)
421 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
422 else if (alert_desc == SSL_AD_BAD_RECORD_MAC)
423 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
424
425 al = alert_desc;
426 goto fatal_err;
427 }
428
429 /* we have pulled in a full packet so zero things */
430 s->packet_length = 0;
431
432 if (tls_content_remaining(s->s3->rcontent) == 0) {
433 /*
434 * Zero-length fragments are only permitted for application
435 * data, as per RFC 5246 section 6.2.1.
436 */
437 if (rr->type != SSL3_RT_APPLICATION_DATA) {
438 SSLerror(s, SSL_R_BAD_LENGTH);
439 al = SSL_AD_UNEXPECTED_MESSAGE;
440 goto fatal_err;
441 }
442
443 tls_content_clear(s->s3->rcontent);
444
445 /*
446 * CBC countermeasures for known IV weaknesses can legitimately
447 * insert a single empty record, so we allow ourselves to read
448 * once past a single empty record without forcing want_read.
449 */
450 if (s->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) {
451 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY);
452 return -1;
453 }
454 if (s->empty_record_count > 1) {
455 ssl_force_want_read(s);
456 return -1;
457 }
458 goto again;
459 }
460
461 s->empty_record_count = 0;
462
463 return (1);
464
465 fatal_err:
466 ssl3_send_alert(s, SSL3_AL_FATAL, al);
467 err:
468 return (ret);
469 }
470
471 /* Call this to write data in records of type 'type'
472 * It will return <= 0 if not all data has been sent or non-blocking IO.
473 */
474 int
ssl3_write_bytes(SSL * s,int type,const void * buf_,int len)475 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
476 {
477 const unsigned char *buf = buf_;
478 unsigned int tot, n, nw;
479 int i;
480
481 if (len < 0) {
482 SSLerror(s, ERR_R_INTERNAL_ERROR);
483 return -1;
484 }
485
486 s->rwstate = SSL_NOTHING;
487 tot = s->s3->wnum;
488 s->s3->wnum = 0;
489
490 if (SSL_in_init(s) && !s->in_handshake) {
491 i = s->handshake_func(s);
492 if (i < 0)
493 return (i);
494 if (i == 0) {
495 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
496 return -1;
497 }
498 }
499
500 if (len < tot)
501 len = tot;
502 n = (len - tot);
503 for (;;) {
504 if (n > s->max_send_fragment)
505 nw = s->max_send_fragment;
506 else
507 nw = n;
508
509 i = do_ssl3_write(s, type, &(buf[tot]), nw);
510 if (i <= 0) {
511 s->s3->wnum = tot;
512 return i;
513 }
514
515 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA &&
516 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
517 /*
518 * Next chunk of data should get another prepended
519 * empty fragment in ciphersuites with known-IV
520 * weakness.
521 */
522 s->s3->empty_fragment_done = 0;
523
524 return tot + i;
525 }
526
527 n -= i;
528 tot += i;
529 }
530 }
531
532 static int
do_ssl3_write(SSL * s,int type,const unsigned char * buf,unsigned int len)533 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
534 {
535 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf);
536 SSL_SESSION *sess = s->session;
537 int need_empty_fragment = 0;
538 size_t align, out_len;
539 CBB cbb;
540 int ret;
541
542 memset(&cbb, 0, sizeof(cbb));
543
544 if (wb->buf == NULL)
545 if (!ssl3_setup_write_buffer(s))
546 return -1;
547
548 /*
549 * First check if there is a SSL3_BUFFER_INTERNAL still being written
550 * out. This will happen with non blocking IO.
551 */
552 if (wb->left != 0)
553 return (ssl3_write_pending(s, type, buf, len));
554
555 /* If we have an alert to send, let's send it. */
556 if (s->s3->alert_dispatch) {
557 if ((ret = ssl3_dispatch_alert(s)) <= 0)
558 return (ret);
559 /* If it went, fall through and send more stuff. */
560
561 /* We may have released our buffer, if so get it again. */
562 if (wb->buf == NULL)
563 if (!ssl3_setup_write_buffer(s))
564 return -1;
565 }
566
567 if (len == 0)
568 return 0;
569
570 /*
571 * Countermeasure against known-IV weakness in CBC ciphersuites
572 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this
573 * is unnecessary for AEAD.
574 */
575 if (sess != NULL && tls12_record_layer_write_protected(s->rl)) {
576 if (s->s3->need_empty_fragments &&
577 !s->s3->empty_fragment_done &&
578 type == SSL3_RT_APPLICATION_DATA)
579 need_empty_fragment = 1;
580 }
581
582 /*
583 * An extra fragment would be a couple of cipher blocks, which would
584 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real
585 * payload, then we can just simply pretend we have two headers.
586 */
587 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH;
588 if (need_empty_fragment)
589 align += SSL3_RT_HEADER_LENGTH;
590 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
591 wb->offset = align;
592
593 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align))
594 goto err;
595
596 tls12_record_layer_set_version(s->rl, s->version);
597
598 if (need_empty_fragment) {
599 if (!tls12_record_layer_seal_record(s->rl, type,
600 buf, 0, &cbb))
601 goto err;
602 s->s3->empty_fragment_done = 1;
603 }
604
605 if (!tls12_record_layer_seal_record(s->rl, type, buf, len, &cbb))
606 goto err;
607
608 if (!CBB_finish(&cbb, NULL, &out_len))
609 goto err;
610
611 wb->left = out_len;
612
613 /*
614 * Memorize arguments so that ssl3_write_pending can detect
615 * bad write retries later.
616 */
617 s->s3->wpend_tot = len;
618 s->s3->wpend_buf = buf;
619 s->s3->wpend_type = type;
620 s->s3->wpend_ret = len;
621
622 /* We now just need to write the buffer. */
623 return ssl3_write_pending(s, type, buf, len);
624
625 err:
626 CBB_cleanup(&cbb);
627
628 return -1;
629 }
630
631 /* if s->s3->wbuf.left != 0, we need to call this */
632 int
ssl3_write_pending(SSL * s,int type,const unsigned char * buf,unsigned int len)633 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len)
634 {
635 int i;
636 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf);
637
638 /* XXXX */
639 if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) &&
640 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
641 (s->s3->wpend_type != type)) {
642 SSLerror(s, SSL_R_BAD_WRITE_RETRY);
643 return (-1);
644 }
645
646 for (;;) {
647 errno = 0;
648 if (s->wbio != NULL) {
649 s->rwstate = SSL_WRITING;
650 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]),
651 (unsigned int)wb->left);
652 } else {
653 SSLerror(s, SSL_R_BIO_NOT_SET);
654 i = -1;
655 }
656 if (i == wb->left) {
657 wb->left = 0;
658 wb->offset += i;
659 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
660 !SSL_is_dtls(s))
661 ssl3_release_write_buffer(s);
662 s->rwstate = SSL_NOTHING;
663 return (s->s3->wpend_ret);
664 } else if (i <= 0) {
665 /*
666 * For DTLS, just drop it. That's kind of the
667 * whole point in using a datagram service.
668 */
669 if (SSL_is_dtls(s))
670 wb->left = 0;
671 return (i);
672 }
673 wb->offset += i;
674 wb->left -= i;
675 }
676 }
677
678 static ssize_t
ssl3_read_cb(void * buf,size_t n,void * cb_arg)679 ssl3_read_cb(void *buf, size_t n, void *cb_arg)
680 {
681 SSL *s = cb_arg;
682
683 return tls_content_read(s->s3->rcontent, buf, n);
684 }
685
686 #define SSL3_ALERT_LENGTH 2
687
688 int
ssl3_read_alert(SSL * s)689 ssl3_read_alert(SSL *s)
690 {
691 uint8_t alert_level, alert_descr;
692 ssize_t ret;
693 CBS cbs;
694
695 /*
696 * TLSv1.2 permits an alert to be fragmented across multiple records or
697 * for multiple alerts to be be coalesced into a single alert record.
698 * In the case of DTLS, there is no way to reassemble an alert
699 * fragmented across multiple records, hence a full alert must be
700 * available in the record.
701 */
702 if (s->s3->alert_fragment == NULL) {
703 if ((s->s3->alert_fragment = tls_buffer_new(0)) == NULL)
704 return -1;
705 tls_buffer_set_capacity_limit(s->s3->alert_fragment,
706 SSL3_ALERT_LENGTH);
707 }
708 ret = tls_buffer_extend(s->s3->alert_fragment, SSL3_ALERT_LENGTH,
709 ssl3_read_cb, s);
710 if (ret <= 0 && ret != TLS_IO_WANT_POLLIN)
711 return -1;
712 if (ret != SSL3_ALERT_LENGTH) {
713 if (SSL_is_dtls(s)) {
714 SSLerror(s, SSL_R_BAD_LENGTH);
715 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
716 return -1;
717 }
718 return 1;
719 }
720
721 if (!tls_buffer_data(s->s3->alert_fragment, &cbs))
722 return -1;
723
724 ssl_msg_callback_cbs(s, 0, SSL3_RT_ALERT, &cbs);
725
726 if (!CBS_get_u8(&cbs, &alert_level))
727 return -1;
728 if (!CBS_get_u8(&cbs, &alert_descr))
729 return -1;
730
731 tls_buffer_free(s->s3->alert_fragment);
732 s->s3->alert_fragment = NULL;
733
734 ssl_info_callback(s, SSL_CB_READ_ALERT,
735 (alert_level << 8) | alert_descr);
736
737 if (alert_level == SSL3_AL_WARNING) {
738 s->s3->warn_alert = alert_descr;
739 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
740 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
741 return 0;
742 }
743 /* We requested renegotiation and the peer rejected it. */
744 if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
745 SSLerror(s, SSL_R_NO_RENEGOTIATION);
746 ssl3_send_alert(s, SSL3_AL_FATAL,
747 SSL_AD_HANDSHAKE_FAILURE);
748 return -1;
749 }
750 } else if (alert_level == SSL3_AL_FATAL) {
751 s->rwstate = SSL_NOTHING;
752 s->s3->fatal_alert = alert_descr;
753 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
754 ERR_asprintf_error_data("SSL alert number %d", alert_descr);
755 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
756 SSL_CTX_remove_session(s->ctx, s->session);
757 return 0;
758 } else {
759 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
760 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
761 return -1;
762 }
763
764 return 1;
765 }
766
767 int
ssl3_read_change_cipher_spec(SSL * s)768 ssl3_read_change_cipher_spec(SSL *s)
769 {
770 const uint8_t ccs[1] = { SSL3_MT_CCS };
771
772 /*
773 * 'Change Cipher Spec' is just a single byte, so we know exactly what
774 * the record payload has to look like.
775 */
776 if (tls_content_remaining(s->s3->rcontent) != sizeof(ccs)) {
777 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
778 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
779 return -1;
780 }
781 if (!tls_content_equal(s->s3->rcontent, ccs, sizeof(ccs))) {
782 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
783 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
784 return -1;
785 }
786
787 /* XDTLS: check that epoch is consistent */
788
789 ssl_msg_callback_cbs(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC,
790 tls_content_cbs(s->s3->rcontent));
791
792 /* Check that we have a cipher to change to. */
793 if (s->s3->hs.cipher == NULL) {
794 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
795 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
796 return -1;
797 }
798
799 /* Check that we should be receiving a Change Cipher Spec. */
800 if (SSL_is_dtls(s)) {
801 if (!s->d1->change_cipher_spec_ok) {
802 /*
803 * We can't process a CCS now, because previous
804 * handshake messages are still missing, so just
805 * drop it.
806 */
807 tls_content_clear(s->s3->rcontent);
808 return 1;
809 }
810 s->d1->change_cipher_spec_ok = 0;
811 } else {
812 if ((s->s3->flags & SSL3_FLAGS_CCS_OK) == 0) {
813 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
814 ssl3_send_alert(s, SSL3_AL_FATAL,
815 SSL_AD_UNEXPECTED_MESSAGE);
816 return -1;
817 }
818 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
819 }
820
821 tls_content_clear(s->s3->rcontent);
822
823 s->s3->change_cipher_spec = 1;
824 if (!ssl3_do_change_cipher_spec(s))
825 return -1;
826
827 return 1;
828 }
829
830 static int
ssl3_read_handshake_unexpected(SSL * s)831 ssl3_read_handshake_unexpected(SSL *s)
832 {
833 uint32_t hs_msg_length;
834 uint8_t hs_msg_type;
835 ssize_t ssret;
836 CBS cbs;
837 int ret;
838
839 /*
840 * We need four bytes of handshake data so we have a handshake message
841 * header - this may be in the same record or fragmented across multiple
842 * records.
843 */
844 if (s->s3->handshake_fragment == NULL) {
845 if ((s->s3->handshake_fragment = tls_buffer_new(0)) == NULL)
846 return -1;
847 tls_buffer_set_capacity_limit(s->s3->handshake_fragment,
848 SSL3_HM_HEADER_LENGTH);
849 }
850 ssret = tls_buffer_extend(s->s3->handshake_fragment, SSL3_HM_HEADER_LENGTH,
851 ssl3_read_cb, s);
852 if (ssret <= 0 && ssret != TLS_IO_WANT_POLLIN)
853 return -1;
854 if (ssret != SSL3_HM_HEADER_LENGTH)
855 return 1;
856
857 if (s->in_handshake) {
858 SSLerror(s, ERR_R_INTERNAL_ERROR);
859 return -1;
860 }
861
862 /*
863 * This code currently deals with HelloRequest and ClientHello messages -
864 * anything else is pushed to the handshake_func. Almost all of this
865 * belongs in the client/server handshake code.
866 */
867
868 /* Parse handshake message header. */
869 if (!tls_buffer_data(s->s3->handshake_fragment, &cbs))
870 return -1;
871 if (!CBS_get_u8(&cbs, &hs_msg_type))
872 return -1;
873 if (!CBS_get_u24(&cbs, &hs_msg_length))
874 return -1;
875
876 if (hs_msg_type == SSL3_MT_HELLO_REQUEST) {
877 /*
878 * Incoming HelloRequest messages should only be received by a
879 * client. A server may send these at any time - a client should
880 * ignore the message if received in the middle of a handshake.
881 * See RFC 5246 sections 7.4 and 7.4.1.1.
882 */
883 if (s->server) {
884 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
885 ssl3_send_alert(s, SSL3_AL_FATAL,
886 SSL_AD_UNEXPECTED_MESSAGE);
887 return -1;
888 }
889
890 if (hs_msg_length != 0) {
891 SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
892 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
893 return -1;
894 }
895
896 if (!tls_buffer_data(s->s3->handshake_fragment, &cbs))
897 return -1;
898 ssl_msg_callback_cbs(s, 0, SSL3_RT_HANDSHAKE, &cbs);
899
900 tls_buffer_free(s->s3->handshake_fragment);
901 s->s3->handshake_fragment = NULL;
902
903 /*
904 * It should be impossible to hit this, but keep the safety
905 * harness for now...
906 */
907 if (s->session == NULL || s->session->cipher == NULL)
908 return 1;
909
910 /*
911 * Ignore this message if we're currently handshaking,
912 * renegotiation is already pending or renegotiation is disabled
913 * via flags.
914 */
915 if (!SSL_is_init_finished(s) || s->s3->renegotiate ||
916 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0)
917 return 1;
918
919 if (!ssl3_renegotiate(s))
920 return 1;
921 if (!ssl3_renegotiate_check(s))
922 return 1;
923
924 } else if (hs_msg_type == SSL3_MT_CLIENT_HELLO) {
925 /*
926 * Incoming ClientHello messages should only be received by a
927 * server. A client may send these in response to server
928 * initiated renegotiation (HelloRequest) or in order to
929 * initiate renegotiation by the client. See RFC 5246 section
930 * 7.4.1.2.
931 */
932 if (!s->server) {
933 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
934 ssl3_send_alert(s, SSL3_AL_FATAL,
935 SSL_AD_UNEXPECTED_MESSAGE);
936 return -1;
937 }
938
939 /*
940 * A client should not be sending a ClientHello unless we're not
941 * currently handshaking.
942 */
943 if (!SSL_is_init_finished(s)) {
944 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
945 ssl3_send_alert(s, SSL3_AL_FATAL,
946 SSL_AD_UNEXPECTED_MESSAGE);
947 return -1;
948 }
949
950 if ((s->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) {
951 ssl3_send_alert(s, SSL3_AL_FATAL,
952 SSL_AD_NO_RENEGOTIATION);
953 return -1;
954 }
955
956 if (s->session == NULL || s->session->cipher == NULL) {
957 SSLerror(s, ERR_R_INTERNAL_ERROR);
958 return -1;
959 }
960
961 /* Client requested renegotiation but it is not permitted. */
962 if (!s->s3->send_connection_binding ||
963 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) {
964 ssl3_send_alert(s, SSL3_AL_WARNING,
965 SSL_AD_NO_RENEGOTIATION);
966 return 1;
967 }
968
969 s->s3->hs.state = SSL_ST_ACCEPT;
970 s->renegotiate = 1;
971 s->new_session = 1;
972
973 } else {
974 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
975 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
976 return -1;
977 }
978
979 if ((ret = s->handshake_func(s)) < 0)
980 return ret;
981 if (ret == 0) {
982 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
983 return -1;
984 }
985
986 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
987 if (s->s3->rbuf.left == 0) {
988 ssl_force_want_read(s);
989 return -1;
990 }
991 }
992
993 /*
994 * We either finished a handshake or ignored the request, now try again
995 * to obtain the (application) data we were asked for.
996 */
997 return 1;
998 }
999
1000 /* Return up to 'len' payload bytes received in 'type' records.
1001 * 'type' is one of the following:
1002 *
1003 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
1004 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
1005 * - 0 (during a shutdown, no data has to be returned)
1006 *
1007 * If we don't have stored data to work from, read a SSL/TLS record first
1008 * (possibly multiple records if we still don't have anything to return).
1009 *
1010 * This function must handle any surprises the peer may have for us, such as
1011 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
1012 * a surprise, but handled as if it were), or renegotiation requests.
1013 * Also if record payloads contain fragments too small to process, we store
1014 * them until there is enough for the respective protocol (the record protocol
1015 * may use arbitrary fragmentation and even interleaving):
1016 * Change cipher spec protocol
1017 * just 1 byte needed, no need for keeping anything stored
1018 * Alert protocol
1019 * 2 bytes needed (AlertLevel, AlertDescription)
1020 * Handshake protocol
1021 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
1022 * to detect unexpected Client Hello and Hello Request messages
1023 * here, anything else is handled by higher layers
1024 * Application data protocol
1025 * none of our business
1026 */
1027 int
ssl3_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)1028 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
1029 {
1030 int rrcount = 0;
1031 ssize_t ssret;
1032 int ret;
1033
1034 if (s->s3->rbuf.buf == NULL) {
1035 if (!ssl3_setup_read_buffer(s))
1036 return -1;
1037 }
1038
1039 if (s->s3->rcontent == NULL) {
1040 if ((s->s3->rcontent = tls_content_new()) == NULL)
1041 return -1;
1042 }
1043
1044 if (len < 0) {
1045 SSLerror(s, ERR_R_INTERNAL_ERROR);
1046 return -1;
1047 }
1048
1049 if (type != 0 && type != SSL3_RT_APPLICATION_DATA &&
1050 type != SSL3_RT_HANDSHAKE) {
1051 SSLerror(s, ERR_R_INTERNAL_ERROR);
1052 return -1;
1053 }
1054 if (peek && type != SSL3_RT_APPLICATION_DATA) {
1055 SSLerror(s, ERR_R_INTERNAL_ERROR);
1056 return -1;
1057 }
1058
1059 if (type == SSL3_RT_HANDSHAKE &&
1060 s->s3->handshake_fragment != NULL &&
1061 tls_buffer_remaining(s->s3->handshake_fragment) > 0) {
1062 ssize_t ssn;
1063
1064 if ((ssn = tls_buffer_read(s->s3->handshake_fragment, buf,
1065 len)) <= 0)
1066 return -1;
1067
1068 if (tls_buffer_remaining(s->s3->handshake_fragment) == 0) {
1069 tls_buffer_free(s->s3->handshake_fragment);
1070 s->s3->handshake_fragment = NULL;
1071 }
1072
1073 return (int)ssn;
1074 }
1075
1076 if (SSL_in_init(s) && !s->in_handshake) {
1077 if ((ret = s->handshake_func(s)) < 0)
1078 return ret;
1079 if (ret == 0) {
1080 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
1081 return -1;
1082 }
1083 }
1084
1085 start:
1086 /*
1087 * Do not process more than three consecutive records, otherwise the
1088 * peer can cause us to loop indefinitely. Instead, return with an
1089 * SSL_ERROR_WANT_READ so the caller can choose when to handle further
1090 * processing. In the future, the total number of non-handshake and
1091 * non-application data records per connection should probably also be
1092 * limited...
1093 */
1094 if (rrcount++ >= 3) {
1095 ssl_force_want_read(s);
1096 return -1;
1097 }
1098
1099 s->rwstate = SSL_NOTHING;
1100
1101 if (tls_content_remaining(s->s3->rcontent) == 0) {
1102 if ((ret = ssl3_get_record(s)) <= 0)
1103 return ret;
1104 }
1105
1106 /* We now have a packet which can be read and processed. */
1107
1108 if (s->s3->change_cipher_spec &&
1109 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) {
1110 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1111 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
1112 return -1;
1113 }
1114
1115 /*
1116 * If the other end has shut down, throw anything we read away (even in
1117 * 'peek' mode).
1118 */
1119 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
1120 s->rwstate = SSL_NOTHING;
1121 tls_content_clear(s->s3->rcontent);
1122 s->s3->rrec.length = 0;
1123 return 0;
1124 }
1125
1126 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1127 if (tls_content_type(s->s3->rcontent) == type) {
1128 /*
1129 * Make sure that we are not getting application data when we
1130 * are doing a handshake for the first time.
1131 */
1132 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
1133 !tls12_record_layer_read_protected(s->rl)) {
1134 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE);
1135 ssl3_send_alert(s, SSL3_AL_FATAL,
1136 SSL_AD_UNEXPECTED_MESSAGE);
1137 return -1;
1138 }
1139
1140 if (len <= 0)
1141 return len;
1142
1143 if (peek) {
1144 ssret = tls_content_peek(s->s3->rcontent, buf, len);
1145 } else {
1146 ssret = tls_content_read(s->s3->rcontent, buf, len);
1147 }
1148 if (ssret < INT_MIN || ssret > INT_MAX)
1149 return -1;
1150 if (ssret < 0)
1151 return (int)ssret;
1152
1153 if (tls_content_remaining(s->s3->rcontent) == 0) {
1154 s->rstate = SSL_ST_READ_HEADER;
1155
1156 if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
1157 s->s3->rbuf.left == 0)
1158 ssl3_release_read_buffer(s);
1159 }
1160
1161 return ssret;
1162 }
1163
1164 if (tls_content_type(s->s3->rcontent) == SSL3_RT_ALERT) {
1165 if ((ret = ssl3_read_alert(s)) <= 0)
1166 return ret;
1167 goto start;
1168 }
1169
1170 if (s->shutdown & SSL_SENT_SHUTDOWN) {
1171 s->rwstate = SSL_NOTHING;
1172 tls_content_clear(s->s3->rcontent);
1173 s->s3->rrec.length = 0;
1174 return 0;
1175 }
1176
1177 if (tls_content_type(s->s3->rcontent) == SSL3_RT_APPLICATION_DATA) {
1178 /*
1179 * At this point, we were expecting handshake data, but have
1180 * application data. If the library was running inside
1181 * ssl3_read() (i.e. in_read_app_data is set) and it makes
1182 * sense to read application data at this point (session
1183 * renegotiation not yet started), we will indulge it.
1184 */
1185 if (s->s3->in_read_app_data != 0 &&
1186 s->s3->total_renegotiations != 0 &&
1187 (((s->s3->hs.state & SSL_ST_CONNECT) &&
1188 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1189 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || (
1190 (s->s3->hs.state & SSL_ST_ACCEPT) &&
1191 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
1192 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
1193 s->s3->in_read_app_data = 2;
1194 return -1;
1195 } else {
1196 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1197 ssl3_send_alert(s, SSL3_AL_FATAL,
1198 SSL_AD_UNEXPECTED_MESSAGE);
1199 return -1;
1200 }
1201 }
1202
1203 if (tls_content_type(s->s3->rcontent) == SSL3_RT_CHANGE_CIPHER_SPEC) {
1204 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0)
1205 return ret;
1206 goto start;
1207 }
1208
1209 if (tls_content_type(s->s3->rcontent) == SSL3_RT_HANDSHAKE) {
1210 if ((ret = ssl3_read_handshake_unexpected(s)) <= 0)
1211 return ret;
1212 goto start;
1213 }
1214
1215 /*
1216 * Unknown record type - TLSv1.2 sends an unexpected message alert while
1217 * earlier versions silently ignore the record.
1218 */
1219 if (ssl_effective_tls_version(s) <= TLS1_1_VERSION) {
1220 tls_content_clear(s->s3->rcontent);
1221 goto start;
1222 }
1223 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1224 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
1225 return -1;
1226 }
1227
1228 int
ssl3_do_change_cipher_spec(SSL * s)1229 ssl3_do_change_cipher_spec(SSL *s)
1230 {
1231 if (s->s3->hs.tls12.key_block == NULL) {
1232 if (s->session == NULL || s->session->master_key_length == 0) {
1233 /* might happen if dtls1_read_bytes() calls this */
1234 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1235 return (0);
1236 }
1237
1238 s->session->cipher = s->s3->hs.cipher;
1239 if (!tls1_setup_key_block(s))
1240 return (0);
1241 }
1242
1243 if (!tls1_change_read_cipher_state(s))
1244 return (0);
1245
1246 /*
1247 * We have to record the message digest at this point so we can get it
1248 * before we read the finished message.
1249 */
1250 if (!tls12_derive_peer_finished(s))
1251 return (0);
1252
1253 return (1);
1254 }
1255
1256 static int
ssl3_write_alert(SSL * s)1257 ssl3_write_alert(SSL *s)
1258 {
1259 if (SSL_is_dtls(s))
1260 return do_dtls1_write(s, SSL3_RT_ALERT, s->s3->send_alert,
1261 sizeof(s->s3->send_alert));
1262
1263 return do_ssl3_write(s, SSL3_RT_ALERT, s->s3->send_alert,
1264 sizeof(s->s3->send_alert));
1265 }
1266
1267 int
ssl3_send_alert(SSL * s,int level,int desc)1268 ssl3_send_alert(SSL *s, int level, int desc)
1269 {
1270 /* If alert is fatal, remove session from cache. */
1271 if (level == SSL3_AL_FATAL)
1272 SSL_CTX_remove_session(s->ctx, s->session);
1273
1274 s->s3->alert_dispatch = 1;
1275 s->s3->send_alert[0] = level;
1276 s->s3->send_alert[1] = desc;
1277
1278 /*
1279 * If data is still being written out, the alert will be dispatched at
1280 * some point in the future.
1281 */
1282 if (s->s3->wbuf.left != 0)
1283 return -1;
1284
1285 return ssl3_dispatch_alert(s);
1286 }
1287
1288 int
ssl3_dispatch_alert(SSL * s)1289 ssl3_dispatch_alert(SSL *s)
1290 {
1291 int ret;
1292
1293 s->s3->alert_dispatch = 0;
1294 if ((ret = ssl3_write_alert(s)) <= 0) {
1295 s->s3->alert_dispatch = 1;
1296 return ret;
1297 }
1298
1299 /*
1300 * Alert sent to BIO. If it is important, flush it now.
1301 * If the message does not get sent due to non-blocking IO,
1302 * we will not worry too much.
1303 */
1304 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1305 (void)BIO_flush(s->wbio);
1306
1307 ssl_msg_callback(s, 1, SSL3_RT_ALERT, s->s3->send_alert, 2);
1308
1309 ssl_info_callback(s, SSL_CB_WRITE_ALERT,
1310 (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]);
1311
1312 return ret;
1313 }
1314