1 /* $OpenBSD: ssl_pkt.c,v 1.60 2022/09/11 13:51:25 jsing 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 <stdio.h>
114
115 #include <openssl/buffer.h>
116 #include <openssl/evp.h>
117
118 #include "bytestring.h"
119 #include "dtls_locl.h"
120 #include "ssl_locl.h"
121
122 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
123 unsigned int len);
124 static int ssl3_get_record(SSL *s);
125
126 /*
127 * Force a WANT_READ return for certain error conditions where
128 * we don't want to spin internally.
129 */
130 void
ssl_force_want_read(SSL * s)131 ssl_force_want_read(SSL *s)
132 {
133 BIO *bio;
134
135 bio = SSL_get_rbio(s);
136 BIO_clear_retry_flags(bio);
137 BIO_set_retry_read(bio);
138
139 s->internal->rwstate = SSL_READING;
140 }
141
142 /*
143 * If extend == 0, obtain new n-byte packet; if extend == 1, increase
144 * packet by another n bytes.
145 * The packet will be in the sub-array of s->s3->rbuf.buf specified
146 * by s->internal->packet and s->internal->packet_length.
147 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf
148 * [plus s->internal->packet_length bytes if extend == 1].)
149 */
150 static int
ssl3_read_n(SSL * s,int n,int max,int extend)151 ssl3_read_n(SSL *s, int n, int max, int extend)
152 {
153 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf);
154 int i, len, left;
155 size_t align;
156 unsigned char *pkt;
157
158 if (n <= 0)
159 return n;
160
161 if (rb->buf == NULL)
162 if (!ssl3_setup_read_buffer(s))
163 return -1;
164
165 left = rb->left;
166 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH;
167 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
168
169 if (!extend) {
170 /* start with empty packet ... */
171 if (left == 0)
172 rb->offset = align;
173 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) {
174 /* check if next packet length is large
175 * enough to justify payload alignment... */
176 pkt = rb->buf + rb->offset;
177 if (pkt[0] == SSL3_RT_APPLICATION_DATA &&
178 (pkt[3]<<8|pkt[4]) >= 128) {
179 /* Note that even if packet is corrupted
180 * and its length field is insane, we can
181 * only be led to wrong decision about
182 * whether memmove will occur or not.
183 * Header values has no effect on memmove
184 * arguments and therefore no buffer
185 * overrun can be triggered. */
186 memmove(rb->buf + align, pkt, left);
187 rb->offset = align;
188 }
189 }
190 s->internal->packet = rb->buf + rb->offset;
191 s->internal->packet_length = 0;
192 /* ... now we can act as if 'extend' was set */
193 }
194
195 /* For DTLS/UDP reads should not span multiple packets
196 * because the read operation returns the whole packet
197 * at once (as long as it fits into the buffer). */
198 if (SSL_is_dtls(s)) {
199 if (left > 0 && n > left)
200 n = left;
201 }
202
203 /* if there is enough in the buffer from a previous read, take some */
204 if (left >= n) {
205 s->internal->packet_length += n;
206 rb->left = left - n;
207 rb->offset += n;
208 return (n);
209 }
210
211 /* else we need to read more data */
212
213 len = s->internal->packet_length;
214 pkt = rb->buf + align;
215 /* Move any available bytes to front of buffer:
216 * 'len' bytes already pointed to by 'packet',
217 * 'left' extra ones at the end */
218 if (s->internal->packet != pkt) {
219 /* len > 0 */
220 memmove(pkt, s->internal->packet, len + left);
221 s->internal->packet = pkt;
222 rb->offset = len + align;
223 }
224
225 if (n > (int)(rb->len - rb->offset)) {
226 /* does not happen */
227 SSLerror(s, ERR_R_INTERNAL_ERROR);
228 return -1;
229 }
230
231 if (s->internal->read_ahead || SSL_is_dtls(s)) {
232 if (max < n)
233 max = n;
234 if (max > (int)(rb->len - rb->offset))
235 max = rb->len - rb->offset;
236 } else {
237 /* ignore max parameter */
238 max = n;
239 }
240
241 while (left < n) {
242 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
243 * and need to read in more until we have len+n (up to
244 * len+max if possible) */
245
246 errno = 0;
247 if (s->rbio != NULL) {
248 s->internal->rwstate = SSL_READING;
249 i = BIO_read(s->rbio, pkt + len + left, max - left);
250 } else {
251 SSLerror(s, SSL_R_READ_BIO_NOT_SET);
252 i = -1;
253 }
254
255 if (i <= 0) {
256 rb->left = left;
257 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
258 !SSL_is_dtls(s)) {
259 if (len + left == 0)
260 ssl3_release_read_buffer(s);
261 }
262 return (i);
263 }
264 left += i;
265
266 /*
267 * reads should *never* span multiple packets for DTLS because
268 * the underlying transport protocol is message oriented as
269 * opposed to byte oriented as in the TLS case.
270 */
271 if (SSL_is_dtls(s)) {
272 if (n > left)
273 n = left; /* makes the while condition false */
274 }
275 }
276
277 /* done reading, now the book-keeping */
278 rb->offset += n;
279 rb->left = left - n;
280 s->internal->packet_length += n;
281 s->internal->rwstate = SSL_NOTHING;
282
283 return (n);
284 }
285
286 int
ssl3_packet_read(SSL * s,int plen)287 ssl3_packet_read(SSL *s, int plen)
288 {
289 int n;
290
291 n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0);
292 if (n <= 0)
293 return n;
294 if (s->internal->packet_length < plen)
295 return s->internal->packet_length;
296
297 return plen;
298 }
299
300 int
ssl3_packet_extend(SSL * s,int plen)301 ssl3_packet_extend(SSL *s, int plen)
302 {
303 int rlen, n;
304
305 if (s->internal->packet_length >= plen)
306 return plen;
307 rlen = plen - s->internal->packet_length;
308
309 n = ssl3_read_n(s, rlen, rlen, 1);
310 if (n <= 0)
311 return n;
312 if (s->internal->packet_length < plen)
313 return s->internal->packet_length;
314
315 return plen;
316 }
317
318 /* Call this to get a new input record.
319 * It will return <= 0 if more data is needed, normally due to an error
320 * or non-blocking IO.
321 * When it finishes, one packet has been decoded and can be found in
322 * ssl->s3->internal->rrec.type - is the type of record
323 * ssl->s3->internal->rrec.data, - data
324 * ssl->s3->internal->rrec.length, - number of bytes
325 */
326 /* used only by ssl3_read_bytes */
327 static int
ssl3_get_record(SSL * s)328 ssl3_get_record(SSL *s)
329 {
330 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf);
331 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec);
332 uint8_t alert_desc;
333 uint8_t *out;
334 size_t out_len;
335 int al, n;
336 int ret = -1;
337
338 again:
339 /* check if we have the header */
340 if ((s->internal->rstate != SSL_ST_READ_BODY) ||
341 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) {
342 CBS header;
343 uint16_t len, ssl_version;
344 uint8_t type;
345
346 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH);
347 if (n <= 0)
348 return (n);
349
350 s->internal->mac_packet = 1;
351 s->internal->rstate = SSL_ST_READ_BODY;
352
353 if (s->server && s->internal->first_packet) {
354 if ((ret = ssl_server_legacy_first_packet(s)) != 1)
355 return (ret);
356 ret = -1;
357 }
358
359 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH);
360
361 /* Pull apart the header into the SSL3_RECORD_INTERNAL */
362 if (!CBS_get_u8(&header, &type) ||
363 !CBS_get_u16(&header, &ssl_version) ||
364 !CBS_get_u16(&header, &len)) {
365 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
366 goto err;
367 }
368
369 rr->type = type;
370 rr->length = len;
371
372 /* Lets check version */
373 if (!s->internal->first_packet && ssl_version != s->version) {
374 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) &&
375 !tls12_record_layer_write_protected(s->internal->rl)) {
376 /* Send back error using their minor version number :-) */
377 s->version = ssl_version;
378 }
379 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
380 al = SSL_AD_PROTOCOL_VERSION;
381 goto fatal_err;
382 }
383
384 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) {
385 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
386 goto err;
387 }
388
389 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) {
390 al = SSL_AD_RECORD_OVERFLOW;
391 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG);
392 goto fatal_err;
393 }
394 }
395
396 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length);
397 if (n <= 0)
398 return (n);
399 if (n != SSL3_RT_HEADER_LENGTH + rr->length)
400 return (n);
401
402 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
403
404 /*
405 * A full record has now been read from the wire, which now needs
406 * to be processed.
407 */
408 tls12_record_layer_set_version(s->internal->rl, s->version);
409
410 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet,
411 s->internal->packet_length, &out, &out_len)) {
412 tls12_record_layer_alert(s->internal->rl, &alert_desc);
413
414 if (alert_desc == 0)
415 goto err;
416
417 if (alert_desc == SSL_AD_RECORD_OVERFLOW)
418 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
419 else if (alert_desc == SSL_AD_BAD_RECORD_MAC)
420 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
421
422 al = alert_desc;
423 goto fatal_err;
424 }
425
426 rr->data = out;
427 rr->length = out_len;
428 rr->off = 0;
429
430 /* we have pulled in a full packet so zero things */
431 s->internal->packet_length = 0;
432
433 if (rr->length == 0) {
434 /*
435 * Zero-length fragments are only permitted for application
436 * data, as per RFC 5246 section 6.2.1.
437 */
438 if (rr->type != SSL3_RT_APPLICATION_DATA) {
439 SSLerror(s, SSL_R_BAD_LENGTH);
440 al = SSL_AD_UNEXPECTED_MESSAGE;
441 goto fatal_err;
442 }
443
444 /*
445 * CBC countermeasures for known IV weaknesses can legitimately
446 * insert a single empty record, so we allow ourselves to read
447 * once past a single empty record without forcing want_read.
448 */
449 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) {
450 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY);
451 return -1;
452 }
453 if (s->internal->empty_record_count > 1) {
454 ssl_force_want_read(s);
455 return -1;
456 }
457 goto again;
458 }
459
460 s->internal->empty_record_count = 0;
461
462 return (1);
463
464 fatal_err:
465 ssl3_send_alert(s, SSL3_AL_FATAL, al);
466 err:
467 return (ret);
468 }
469
470 /* Call this to write data in records of type 'type'
471 * It will return <= 0 if not all data has been sent or non-blocking IO.
472 */
473 int
ssl3_write_bytes(SSL * s,int type,const void * buf_,int len)474 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
475 {
476 const unsigned char *buf = buf_;
477 unsigned int tot, n, nw;
478 int i;
479
480 if (len < 0) {
481 SSLerror(s, ERR_R_INTERNAL_ERROR);
482 return -1;
483 }
484
485 s->internal->rwstate = SSL_NOTHING;
486 tot = s->s3->wnum;
487 s->s3->wnum = 0;
488
489 if (SSL_in_init(s) && !s->internal->in_handshake) {
490 i = s->internal->handshake_func(s);
491 if (i < 0)
492 return (i);
493 if (i == 0) {
494 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
495 return -1;
496 }
497 }
498
499 if (len < tot)
500 len = tot;
501 n = (len - tot);
502 for (;;) {
503 if (n > s->max_send_fragment)
504 nw = s->max_send_fragment;
505 else
506 nw = n;
507
508 i = do_ssl3_write(s, type, &(buf[tot]), nw);
509 if (i <= 0) {
510 s->s3->wnum = tot;
511 return i;
512 }
513
514 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA &&
515 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
516 /*
517 * Next chunk of data should get another prepended
518 * empty fragment in ciphersuites with known-IV
519 * weakness.
520 */
521 s->s3->empty_fragment_done = 0;
522
523 return tot + i;
524 }
525
526 n -= i;
527 tot += i;
528 }
529 }
530
531 static int
do_ssl3_write(SSL * s,int type,const unsigned char * buf,unsigned int len)532 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
533 {
534 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf);
535 SSL_SESSION *sess = s->session;
536 int need_empty_fragment = 0;
537 size_t align, out_len;
538 uint16_t version;
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 * Some servers hang if initial client hello is larger than 256
572 * bytes and record version number > TLS 1.0.
573 */
574 version = s->version;
575 if (s->s3->hs.state == SSL3_ST_CW_CLNT_HELLO_B &&
576 !s->internal->renegotiate &&
577 s->s3->hs.our_max_tls_version > TLS1_VERSION)
578 version = TLS1_VERSION;
579
580 /*
581 * Countermeasure against known-IV weakness in CBC ciphersuites
582 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this
583 * is unnecessary for AEAD.
584 */
585 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) {
586 if (s->s3->need_empty_fragments &&
587 !s->s3->empty_fragment_done &&
588 type == SSL3_RT_APPLICATION_DATA)
589 need_empty_fragment = 1;
590 }
591
592 /*
593 * An extra fragment would be a couple of cipher blocks, which would
594 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real
595 * payload, then we can just simply pretend we have two headers.
596 */
597 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH;
598 if (need_empty_fragment)
599 align += SSL3_RT_HEADER_LENGTH;
600 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
601 wb->offset = align;
602
603 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align))
604 goto err;
605
606 tls12_record_layer_set_version(s->internal->rl, version);
607
608 if (need_empty_fragment) {
609 if (!tls12_record_layer_seal_record(s->internal->rl, type,
610 buf, 0, &cbb))
611 goto err;
612 s->s3->empty_fragment_done = 1;
613 }
614
615 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb))
616 goto err;
617
618 if (!CBB_finish(&cbb, NULL, &out_len))
619 goto err;
620
621 wb->left = out_len;
622
623 /*
624 * Memorize arguments so that ssl3_write_pending can detect
625 * bad write retries later.
626 */
627 s->s3->wpend_tot = len;
628 s->s3->wpend_buf = buf;
629 s->s3->wpend_type = type;
630 s->s3->wpend_ret = len;
631
632 /* We now just need to write the buffer. */
633 return ssl3_write_pending(s, type, buf, len);
634
635 err:
636 CBB_cleanup(&cbb);
637
638 return -1;
639 }
640
641 /* if s->s3->wbuf.left != 0, we need to call this */
642 int
ssl3_write_pending(SSL * s,int type,const unsigned char * buf,unsigned int len)643 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len)
644 {
645 int i;
646 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf);
647
648 /* XXXX */
649 if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) &&
650 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
651 (s->s3->wpend_type != type)) {
652 SSLerror(s, SSL_R_BAD_WRITE_RETRY);
653 return (-1);
654 }
655
656 for (;;) {
657 errno = 0;
658 if (s->wbio != NULL) {
659 s->internal->rwstate = SSL_WRITING;
660 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]),
661 (unsigned int)wb->left);
662 } else {
663 SSLerror(s, SSL_R_BIO_NOT_SET);
664 i = -1;
665 }
666 if (i == wb->left) {
667 wb->left = 0;
668 wb->offset += i;
669 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
670 !SSL_is_dtls(s))
671 ssl3_release_write_buffer(s);
672 s->internal->rwstate = SSL_NOTHING;
673 return (s->s3->wpend_ret);
674 } else if (i <= 0) {
675 /*
676 * For DTLS, just drop it. That's kind of the
677 * whole point in using a datagram service.
678 */
679 if (SSL_is_dtls(s))
680 wb->left = 0;
681 return (i);
682 }
683 wb->offset += i;
684 wb->left -= i;
685 }
686 }
687
688 int
ssl3_read_alert(SSL * s)689 ssl3_read_alert(SSL *s)
690 {
691 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec;
692 uint8_t alert_level, alert_descr;
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 while (rr->length > 0 &&
703 s->s3->alert_fragment_len < sizeof(s->s3->alert_fragment)) {
704 s->s3->alert_fragment[s->s3->alert_fragment_len++] =
705 rr->data[rr->off++];
706 rr->length--;
707 }
708 if (s->s3->alert_fragment_len < sizeof(s->s3->alert_fragment)) {
709 if (SSL_is_dtls(s)) {
710 SSLerror(s, SSL_R_BAD_LENGTH);
711 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
712 return -1;
713 }
714 return 1;
715 }
716
717 CBS_init(&cbs, s->s3->alert_fragment, sizeof(s->s3->alert_fragment));
718
719 ssl_msg_callback_cbs(s, 0, SSL3_RT_ALERT, &cbs);
720
721 if (!CBS_get_u8(&cbs, &alert_level))
722 return -1;
723 if (!CBS_get_u8(&cbs, &alert_descr))
724 return -1;
725
726 s->s3->alert_fragment_len = 0;
727
728 ssl_info_callback(s, SSL_CB_READ_ALERT,
729 (alert_level << 8) | alert_descr);
730
731 if (alert_level == SSL3_AL_WARNING) {
732 s->s3->warn_alert = alert_descr;
733 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
734 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
735 return 0;
736 }
737 /* We requested renegotiation and the peer rejected it. */
738 if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
739 SSLerror(s, SSL_R_NO_RENEGOTIATION);
740 ssl3_send_alert(s, SSL3_AL_FATAL,
741 SSL_AD_HANDSHAKE_FAILURE);
742 return -1;
743 }
744 } else if (alert_level == SSL3_AL_FATAL) {
745 s->internal->rwstate = SSL_NOTHING;
746 s->s3->fatal_alert = alert_descr;
747 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
748 ERR_asprintf_error_data("SSL alert number %d", alert_descr);
749 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
750 SSL_CTX_remove_session(s->ctx, s->session);
751 return 0;
752 } else {
753 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
754 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
755 return -1;
756 }
757
758 return 1;
759 }
760
761 int
ssl3_read_change_cipher_spec(SSL * s)762 ssl3_read_change_cipher_spec(SSL *s)
763 {
764 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec;
765 const uint8_t ccs[] = { SSL3_MT_CCS };
766 CBS cbs;
767
768 /*
769 * 'Change Cipher Spec' is just a single byte, so we know exactly what
770 * the record payload has to look like.
771 */
772 CBS_init(&cbs, rr->data, rr->length);
773 if (rr->off != 0 || CBS_len(&cbs) != sizeof(ccs)) {
774 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
775 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
776 return -1;
777 }
778 if (!CBS_mem_equal(&cbs, ccs, sizeof(ccs))) {
779 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
780 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
781 return -1;
782 }
783
784 /* XDTLS: check that epoch is consistent */
785
786 ssl_msg_callback_cbs(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, &cbs);
787
788 /* Check that we have a cipher to change to. */
789 if (s->s3->hs.cipher == NULL) {
790 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
791 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
792 return -1;
793 }
794
795 /* Check that we should be receiving a Change Cipher Spec. */
796 if (SSL_is_dtls(s)) {
797 if (!s->d1->change_cipher_spec_ok) {
798 /*
799 * We can't process a CCS now, because previous
800 * handshake messages are still missing, so just
801 * drop it.
802 */
803 rr->length = 0;
804 return 1;
805 }
806 s->d1->change_cipher_spec_ok = 0;
807 } else {
808 if ((s->s3->flags & SSL3_FLAGS_CCS_OK) == 0) {
809 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
810 ssl3_send_alert(s, SSL3_AL_FATAL,
811 SSL_AD_UNEXPECTED_MESSAGE);
812 return -1;
813 }
814 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
815 }
816
817 rr->length = 0;
818
819 s->s3->change_cipher_spec = 1;
820 if (!ssl3_do_change_cipher_spec(s))
821 return -1;
822
823 return 1;
824 }
825
826 static int
ssl3_read_handshake_unexpected(SSL * s)827 ssl3_read_handshake_unexpected(SSL *s)
828 {
829 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec;
830 uint32_t hs_msg_length;
831 uint8_t hs_msg_type;
832 CBS cbs;
833 int ret;
834
835 /*
836 * We need four bytes of handshake data so we have a handshake message
837 * header - this may be in the same record or fragmented across multiple
838 * records.
839 */
840 while (rr->length > 0 &&
841 s->s3->handshake_fragment_len < sizeof(s->s3->handshake_fragment)) {
842 s->s3->handshake_fragment[s->s3->handshake_fragment_len++] =
843 rr->data[rr->off++];
844 rr->length--;
845 }
846
847 if (s->s3->handshake_fragment_len < sizeof(s->s3->handshake_fragment))
848 return 1;
849
850 if (s->internal->in_handshake) {
851 SSLerror(s, ERR_R_INTERNAL_ERROR);
852 return -1;
853 }
854
855 /*
856 * This code currently deals with HelloRequest and ClientHello messages -
857 * anything else is pushed to the handshake_func. Almost all of this
858 * belongs in the client/server handshake code.
859 */
860
861 /* Parse handshake message header. */
862 CBS_init(&cbs, s->s3->handshake_fragment, s->s3->handshake_fragment_len);
863 if (!CBS_get_u8(&cbs, &hs_msg_type))
864 return -1;
865 if (!CBS_get_u24(&cbs, &hs_msg_length))
866 return -1;
867
868 if (hs_msg_type == SSL3_MT_HELLO_REQUEST) {
869 /*
870 * Incoming HelloRequest messages should only be received by a
871 * client. A server may send these at any time - a client should
872 * ignore the message if received in the middle of a handshake.
873 * See RFC 5246 sections 7.4 and 7.4.1.1.
874 */
875 if (s->server) {
876 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
877 ssl3_send_alert(s, SSL3_AL_FATAL,
878 SSL_AD_UNEXPECTED_MESSAGE);
879 return -1;
880 }
881
882 if (hs_msg_length != 0) {
883 SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
884 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
885 return -1;
886 }
887
888 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE,
889 s->s3->handshake_fragment, s->s3->handshake_fragment_len);
890
891 s->s3->handshake_fragment_len = 0;
892
893 /*
894 * It should be impossible to hit this, but keep the safety
895 * harness for now...
896 */
897 if (s->session == NULL || s->session->cipher == NULL)
898 return 1;
899
900 /*
901 * Ignore this message if we're currently handshaking,
902 * renegotiation is already pending or renegotiation is disabled
903 * via flags.
904 */
905 if (!SSL_is_init_finished(s) || s->s3->renegotiate ||
906 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0)
907 return 1;
908
909 if (!ssl3_renegotiate(s))
910 return 1;
911 if (!ssl3_renegotiate_check(s))
912 return 1;
913
914 } else if (hs_msg_type == SSL3_MT_CLIENT_HELLO) {
915 /*
916 * Incoming ClientHello messages should only be received by a
917 * server. A client may send these in response to server
918 * initiated renegotiation (HelloRequest) or in order to
919 * initiate renegotiation by the client. See RFC 5246 section
920 * 7.4.1.2.
921 */
922 if (!s->server) {
923 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
924 ssl3_send_alert(s, SSL3_AL_FATAL,
925 SSL_AD_UNEXPECTED_MESSAGE);
926 return -1;
927 }
928
929 /*
930 * A client should not be sending a ClientHello unless we're not
931 * currently handshaking.
932 */
933 if (!SSL_is_init_finished(s)) {
934 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
935 ssl3_send_alert(s, SSL3_AL_FATAL,
936 SSL_AD_UNEXPECTED_MESSAGE);
937 return -1;
938 }
939
940 if ((s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) {
941 ssl3_send_alert(s, SSL3_AL_FATAL,
942 SSL_AD_NO_RENEGOTIATION);
943 return -1;
944 }
945
946 if (s->session == NULL || s->session->cipher == NULL) {
947 SSLerror(s, ERR_R_INTERNAL_ERROR);
948 return -1;
949 }
950
951 /* Client requested renegotiation but it is not permitted. */
952 if (!s->s3->send_connection_binding ||
953 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) {
954 ssl3_send_alert(s, SSL3_AL_WARNING,
955 SSL_AD_NO_RENEGOTIATION);
956 return 1;
957 }
958
959 s->s3->hs.state = SSL_ST_ACCEPT;
960 s->internal->renegotiate = 1;
961 s->internal->new_session = 1;
962
963 } else {
964 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
965 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
966 return -1;
967 }
968
969 if ((ret = s->internal->handshake_func(s)) < 0)
970 return ret;
971 if (ret == 0) {
972 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
973 return -1;
974 }
975
976 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
977 if (s->s3->rbuf.left == 0) {
978 ssl_force_want_read(s);
979 return -1;
980 }
981 }
982
983 /*
984 * We either finished a handshake or ignored the request, now try again
985 * to obtain the (application) data we were asked for.
986 */
987 return 1;
988 }
989
990 /* Return up to 'len' payload bytes received in 'type' records.
991 * 'type' is one of the following:
992 *
993 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
994 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
995 * - 0 (during a shutdown, no data has to be returned)
996 *
997 * If we don't have stored data to work from, read a SSL/TLS record first
998 * (possibly multiple records if we still don't have anything to return).
999 *
1000 * This function must handle any surprises the peer may have for us, such as
1001 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
1002 * a surprise, but handled as if it were), or renegotiation requests.
1003 * Also if record payloads contain fragments too small to process, we store
1004 * them until there is enough for the respective protocol (the record protocol
1005 * may use arbitrary fragmentation and even interleaving):
1006 * Change cipher spec protocol
1007 * just 1 byte needed, no need for keeping anything stored
1008 * Alert protocol
1009 * 2 bytes needed (AlertLevel, AlertDescription)
1010 * Handshake protocol
1011 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
1012 * to detect unexpected Client Hello and Hello Request messages
1013 * here, anything else is handled by higher layers
1014 * Application data protocol
1015 * none of our business
1016 */
1017 int
ssl3_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)1018 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
1019 {
1020 SSL3_RECORD_INTERNAL *rr;
1021 int rrcount = 0;
1022 unsigned int n;
1023 int ret;
1024
1025 if (s->s3->rbuf.buf == NULL) {
1026 if (!ssl3_setup_read_buffer(s))
1027 return -1;
1028 }
1029
1030 if (len < 0) {
1031 SSLerror(s, ERR_R_INTERNAL_ERROR);
1032 return -1;
1033 }
1034
1035 if (type != 0 && type != SSL3_RT_APPLICATION_DATA &&
1036 type != SSL3_RT_HANDSHAKE) {
1037 SSLerror(s, ERR_R_INTERNAL_ERROR);
1038 return -1;
1039 }
1040 if (peek && type != SSL3_RT_APPLICATION_DATA) {
1041 SSLerror(s, ERR_R_INTERNAL_ERROR);
1042 return -1;
1043 }
1044
1045 if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment_len > 0) {
1046 /* Partially satisfy request from fragment storage. */
1047 unsigned char *src = s->s3->handshake_fragment;
1048 unsigned char *dst = buf;
1049 unsigned int k;
1050
1051 /* peek == 0 */
1052 n = 0;
1053 while (len > 0 && s->s3->handshake_fragment_len > 0) {
1054 *dst++ = *src++;
1055 len--;
1056 s->s3->handshake_fragment_len--;
1057 n++;
1058 }
1059 /* move any remaining fragment bytes: */
1060 for (k = 0; k < s->s3->handshake_fragment_len; k++)
1061 s->s3->handshake_fragment[k] = *src++;
1062 return n;
1063 }
1064
1065 if (SSL_in_init(s) && !s->internal->in_handshake) {
1066 if ((ret = s->internal->handshake_func(s)) < 0)
1067 return ret;
1068 if (ret == 0) {
1069 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
1070 return -1;
1071 }
1072 }
1073
1074 start:
1075 /*
1076 * Do not process more than three consecutive records, otherwise the
1077 * peer can cause us to loop indefinitely. Instead, return with an
1078 * SSL_ERROR_WANT_READ so the caller can choose when to handle further
1079 * processing. In the future, the total number of non-handshake and
1080 * non-application data records per connection should probably also be
1081 * limited...
1082 */
1083 if (rrcount++ >= 3) {
1084 ssl_force_want_read(s);
1085 return -1;
1086 }
1087
1088 s->internal->rwstate = SSL_NOTHING;
1089
1090 rr = &s->s3->rrec;
1091
1092 if (rr->length == 0 || s->internal->rstate == SSL_ST_READ_BODY) {
1093 if ((ret = ssl3_get_record(s)) <= 0)
1094 return ret;
1095 }
1096
1097 /* We now have a packet which can be read and processed. */
1098
1099 if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE) {
1100 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1101 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
1102 return -1;
1103 }
1104
1105 /*
1106 * If the other end has shut down, throw anything we read away (even in
1107 * 'peek' mode).
1108 */
1109 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) {
1110 s->internal->rwstate = SSL_NOTHING;
1111 rr->length = 0;
1112 return 0;
1113 }
1114
1115 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1116 if (type == rr->type) {
1117 /*
1118 * Make sure that we are not getting application data when we
1119 * are doing a handshake for the first time.
1120 */
1121 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
1122 !tls12_record_layer_read_protected(s->internal->rl)) {
1123 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE);
1124 ssl3_send_alert(s, SSL3_AL_FATAL,
1125 SSL_AD_UNEXPECTED_MESSAGE);
1126 return -1;
1127 }
1128
1129 if (len <= 0)
1130 return len;
1131
1132 if ((unsigned int)len > rr->length)
1133 n = rr->length;
1134 else
1135 n = (unsigned int)len;
1136
1137 memcpy(buf, &rr->data[rr->off], n);
1138 if (!peek) {
1139 memset(&rr->data[rr->off], 0, n);
1140 rr->length -= n;
1141 rr->off += n;
1142 if (rr->length == 0) {
1143 s->internal->rstate = SSL_ST_READ_HEADER;
1144 rr->off = 0;
1145 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
1146 s->s3->rbuf.left == 0)
1147 ssl3_release_read_buffer(s);
1148 }
1149 }
1150
1151 return n;
1152 }
1153
1154 /*
1155 * If we get here, then type != rr->type; if we have a handshake
1156 * message, then it was unexpected (Hello Request or Client Hello).
1157 */
1158
1159 if (rr->type == SSL3_RT_ALERT) {
1160 if ((ret = ssl3_read_alert(s)) <= 0)
1161 return ret;
1162 goto start;
1163 }
1164
1165 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) {
1166 s->internal->rwstate = SSL_NOTHING;
1167 rr->length = 0;
1168 return 0;
1169 }
1170
1171 if (rr->type == SSL3_RT_APPLICATION_DATA) {
1172 /*
1173 * At this point, we were expecting handshake data, but have
1174 * application data. If the library was running inside
1175 * ssl3_read() (i.e. in_read_app_data is set) and it makes
1176 * sense to read application data at this point (session
1177 * renegotiation not yet started), we will indulge it.
1178 */
1179 if (s->s3->in_read_app_data != 0 &&
1180 s->s3->total_renegotiations != 0 &&
1181 (((s->s3->hs.state & SSL_ST_CONNECT) &&
1182 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1183 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || (
1184 (s->s3->hs.state & SSL_ST_ACCEPT) &&
1185 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
1186 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
1187 s->s3->in_read_app_data = 2;
1188 return -1;
1189 } else {
1190 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1191 ssl3_send_alert(s, SSL3_AL_FATAL,
1192 SSL_AD_UNEXPECTED_MESSAGE);
1193 return -1;
1194 }
1195 }
1196
1197 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1198 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0)
1199 return ret;
1200 goto start;
1201 }
1202
1203 if (rr->type == SSL3_RT_HANDSHAKE) {
1204 if ((ret = ssl3_read_handshake_unexpected(s)) <= 0)
1205 return ret;
1206 goto start;
1207 }
1208
1209 /*
1210 * Unknown record type - TLSv1.2 sends an unexpected message alert while
1211 * earlier versions silently ignore the record.
1212 */
1213 if (ssl_effective_tls_version(s) <= TLS1_1_VERSION) {
1214 rr->length = 0;
1215 goto start;
1216 }
1217 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1218 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
1219 return -1;
1220 }
1221
1222 int
ssl3_do_change_cipher_spec(SSL * s)1223 ssl3_do_change_cipher_spec(SSL *s)
1224 {
1225 if (s->s3->hs.tls12.key_block == NULL) {
1226 if (s->session == NULL || s->session->master_key_length == 0) {
1227 /* might happen if dtls1_read_bytes() calls this */
1228 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1229 return (0);
1230 }
1231
1232 s->session->cipher = s->s3->hs.cipher;
1233 if (!tls1_setup_key_block(s))
1234 return (0);
1235 }
1236
1237 if (!tls1_change_read_cipher_state(s))
1238 return (0);
1239
1240 /*
1241 * We have to record the message digest at this point so we can get it
1242 * before we read the finished message.
1243 */
1244 if (!tls12_derive_peer_finished(s))
1245 return (0);
1246
1247 return (1);
1248 }
1249
1250 static int
ssl3_write_alert(SSL * s)1251 ssl3_write_alert(SSL *s)
1252 {
1253 if (SSL_is_dtls(s))
1254 return do_dtls1_write(s, SSL3_RT_ALERT, s->s3->send_alert,
1255 sizeof(s->s3->send_alert));
1256
1257 return do_ssl3_write(s, SSL3_RT_ALERT, s->s3->send_alert,
1258 sizeof(s->s3->send_alert));
1259 }
1260
1261 int
ssl3_send_alert(SSL * s,int level,int desc)1262 ssl3_send_alert(SSL *s, int level, int desc)
1263 {
1264 /* If alert is fatal, remove session from cache. */
1265 if (level == SSL3_AL_FATAL)
1266 SSL_CTX_remove_session(s->ctx, s->session);
1267
1268 s->s3->alert_dispatch = 1;
1269 s->s3->send_alert[0] = level;
1270 s->s3->send_alert[1] = desc;
1271
1272 /*
1273 * If data is still being written out, the alert will be dispatched at
1274 * some point in the future.
1275 */
1276 if (s->s3->wbuf.left != 0)
1277 return -1;
1278
1279 return ssl3_dispatch_alert(s);
1280 }
1281
1282 int
ssl3_dispatch_alert(SSL * s)1283 ssl3_dispatch_alert(SSL *s)
1284 {
1285 int ret;
1286
1287 s->s3->alert_dispatch = 0;
1288 if ((ret = ssl3_write_alert(s)) <= 0) {
1289 s->s3->alert_dispatch = 1;
1290 return ret;
1291 }
1292
1293 /*
1294 * Alert sent to BIO. If it is important, flush it now.
1295 * If the message does not get sent due to non-blocking IO,
1296 * we will not worry too much.
1297 */
1298 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1299 (void)BIO_flush(s->wbio);
1300
1301 ssl_msg_callback(s, 1, SSL3_RT_ALERT, s->s3->send_alert, 2);
1302
1303 ssl_info_callback(s, SSL_CB_WRITE_ALERT,
1304 (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]);
1305
1306 return ret;
1307 }
1308