1 /* $OpenBSD: ssl_pkt.c,v 1.50 2021/08/30 19:25:43 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 static 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 s->internal->rwstate = SSL_READING;
139 }
140
141 /*
142 * If extend == 0, obtain new n-byte packet; if extend == 1, increase
143 * packet by another n bytes.
144 * The packet will be in the sub-array of S3I(s)->rbuf.buf specified
145 * by s->internal->packet and s->internal->packet_length.
146 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf
147 * [plus s->internal->packet_length bytes if extend == 1].)
148 */
149 static int
ssl3_read_n(SSL * s,int n,int max,int extend)150 ssl3_read_n(SSL *s, int n, int max, int extend)
151 {
152 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf);
153 int i, len, left;
154 size_t align;
155 unsigned char *pkt;
156
157 if (n <= 0)
158 return n;
159
160 if (rb->buf == NULL)
161 if (!ssl3_setup_read_buffer(s))
162 return -1;
163
164 left = rb->left;
165 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH;
166 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
167
168 if (!extend) {
169 /* start with empty packet ... */
170 if (left == 0)
171 rb->offset = align;
172 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) {
173 /* check if next packet length is large
174 * enough to justify payload alignment... */
175 pkt = rb->buf + rb->offset;
176 if (pkt[0] == SSL3_RT_APPLICATION_DATA &&
177 (pkt[3]<<8|pkt[4]) >= 128) {
178 /* Note that even if packet is corrupted
179 * and its length field is insane, we can
180 * only be led to wrong decision about
181 * whether memmove will occur or not.
182 * Header values has no effect on memmove
183 * arguments and therefore no buffer
184 * overrun can be triggered. */
185 memmove(rb->buf + align, pkt, left);
186 rb->offset = align;
187 }
188 }
189 s->internal->packet = rb->buf + rb->offset;
190 s->internal->packet_length = 0;
191 /* ... now we can act as if 'extend' was set */
192 }
193
194 /* For DTLS/UDP reads should not span multiple packets
195 * because the read operation returns the whole packet
196 * at once (as long as it fits into the buffer). */
197 if (SSL_is_dtls(s)) {
198 if (left > 0 && n > left)
199 n = left;
200 }
201
202 /* if there is enough in the buffer from a previous read, take some */
203 if (left >= n) {
204 s->internal->packet_length += n;
205 rb->left = left - n;
206 rb->offset += n;
207 return (n);
208 }
209
210 /* else we need to read more data */
211
212 len = s->internal->packet_length;
213 pkt = rb->buf + align;
214 /* Move any available bytes to front of buffer:
215 * 'len' bytes already pointed to by 'packet',
216 * 'left' extra ones at the end */
217 if (s->internal->packet != pkt) {
218 /* len > 0 */
219 memmove(pkt, s->internal->packet, len + left);
220 s->internal->packet = pkt;
221 rb->offset = len + align;
222 }
223
224 if (n > (int)(rb->len - rb->offset)) {
225 /* does not happen */
226 SSLerror(s, ERR_R_INTERNAL_ERROR);
227 return -1;
228 }
229
230 if (s->internal->read_ahead || SSL_is_dtls(s)) {
231 if (max < n)
232 max = n;
233 if (max > (int)(rb->len - rb->offset))
234 max = rb->len - rb->offset;
235 } else {
236 /* ignore max parameter */
237 max = n;
238 }
239
240 while (left < n) {
241 /* Now we have len+left bytes at the front of S3I(s)->rbuf.buf
242 * and need to read in more until we have len+n (up to
243 * len+max if possible) */
244
245 errno = 0;
246 if (s->rbio != NULL) {
247 s->internal->rwstate = SSL_READING;
248 i = BIO_read(s->rbio, pkt + len + left, max - left);
249 } else {
250 SSLerror(s, SSL_R_READ_BIO_NOT_SET);
251 i = -1;
252 }
253
254 if (i <= 0) {
255 rb->left = left;
256 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
257 !SSL_is_dtls(s)) {
258 if (len + left == 0)
259 ssl3_release_read_buffer(s);
260 }
261 return (i);
262 }
263 left += i;
264
265 /*
266 * reads should *never* span multiple packets for DTLS because
267 * the underlying transport protocol is message oriented as
268 * opposed to byte oriented as in the TLS case.
269 */
270 if (SSL_is_dtls(s)) {
271 if (n > left)
272 n = left; /* makes the while condition false */
273 }
274 }
275
276 /* done reading, now the book-keeping */
277 rb->offset += n;
278 rb->left = left - n;
279 s->internal->packet_length += n;
280 s->internal->rwstate = SSL_NOTHING;
281
282 return (n);
283 }
284
285 int
ssl3_packet_read(SSL * s,int plen)286 ssl3_packet_read(SSL *s, int plen)
287 {
288 int n;
289
290 n = ssl3_read_n(s, plen, S3I(s)->rbuf.len, 0);
291 if (n <= 0)
292 return n;
293 if (s->internal->packet_length < plen)
294 return s->internal->packet_length;
295
296 return plen;
297 }
298
299 int
ssl3_packet_extend(SSL * s,int plen)300 ssl3_packet_extend(SSL *s, int plen)
301 {
302 int rlen, n;
303
304 if (s->internal->packet_length >= plen)
305 return plen;
306 rlen = plen - s->internal->packet_length;
307
308 n = ssl3_read_n(s, rlen, rlen, 1);
309 if (n <= 0)
310 return n;
311 if (s->internal->packet_length < plen)
312 return s->internal->packet_length;
313
314 return plen;
315 }
316
317 /* Call this to get a new input record.
318 * It will return <= 0 if more data is needed, normally due to an error
319 * or non-blocking IO.
320 * When it finishes, one packet has been decoded and can be found in
321 * ssl->s3->internal->rrec.type - is the type of record
322 * ssl->s3->internal->rrec.data, - data
323 * ssl->s3->internal->rrec.length, - number of bytes
324 */
325 /* used only by ssl3_read_bytes */
326 static int
ssl3_get_record(SSL * s)327 ssl3_get_record(SSL *s)
328 {
329 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf);
330 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec);
331 uint8_t alert_desc;
332 uint8_t *out;
333 size_t out_len;
334 int al, n;
335 int ret = -1;
336
337 again:
338 /* check if we have the header */
339 if ((s->internal->rstate != SSL_ST_READ_BODY) ||
340 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) {
341 CBS header;
342 uint16_t len, ssl_version;
343 uint8_t type;
344
345 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH);
346 if (n <= 0)
347 return (n);
348
349 s->internal->mac_packet = 1;
350 s->internal->rstate = SSL_ST_READ_BODY;
351
352 if (s->server && s->internal->first_packet) {
353 if ((ret = ssl_server_legacy_first_packet(s)) != 1)
354 return (ret);
355 ret = -1;
356 }
357
358 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH);
359
360 /* Pull apart the header into the SSL3_RECORD_INTERNAL */
361 if (!CBS_get_u8(&header, &type) ||
362 !CBS_get_u16(&header, &ssl_version) ||
363 !CBS_get_u16(&header, &len)) {
364 SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
365 goto err;
366 }
367
368 rr->type = type;
369 rr->length = len;
370
371 /* Lets check version */
372 if (!s->internal->first_packet && ssl_version != s->version) {
373 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) &&
374 !tls12_record_layer_write_protected(s->internal->rl)) {
375 /* Send back error using their minor version number :-) */
376 s->version = ssl_version;
377 }
378 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
379 al = SSL_AD_PROTOCOL_VERSION;
380 goto fatal_err;
381 }
382
383 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) {
384 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
385 goto err;
386 }
387
388 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) {
389 al = SSL_AD_RECORD_OVERFLOW;
390 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG);
391 goto fatal_err;
392 }
393 }
394
395 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length);
396 if (n <= 0)
397 return (n);
398 if (n != SSL3_RT_HEADER_LENGTH + rr->length)
399 return (n);
400
401 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
402
403 /*
404 * A full record has now been read from the wire, which now needs
405 * to be processed.
406 */
407 tls12_record_layer_set_version(s->internal->rl, s->version);
408
409 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet,
410 s->internal->packet_length, &out, &out_len)) {
411 tls12_record_layer_alert(s->internal->rl, &alert_desc);
412
413 if (alert_desc == 0)
414 goto err;
415
416 if (alert_desc == SSL_AD_RECORD_OVERFLOW)
417 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
418 else if (alert_desc == SSL_AD_BAD_RECORD_MAC)
419 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
420
421 al = alert_desc;
422 goto fatal_err;
423 }
424
425 rr->data = out;
426 rr->length = out_len;
427 rr->off = 0;
428
429 /* we have pulled in a full packet so zero things */
430 s->internal->packet_length = 0;
431
432 if (rr->length == 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 /*
444 * CBC countermeasures for known IV weaknesses can legitimately
445 * insert a single empty record, so we allow ourselves to read
446 * once past a single empty record without forcing want_read.
447 */
448 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) {
449 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY);
450 return -1;
451 }
452 if (s->internal->empty_record_count > 1) {
453 ssl_force_want_read(s);
454 return -1;
455 }
456 goto again;
457 }
458
459 s->internal->empty_record_count = 0;
460
461 return (1);
462
463 fatal_err:
464 ssl3_send_alert(s, SSL3_AL_FATAL, al);
465 err:
466 return (ret);
467 }
468
469 /* Call this to write data in records of type 'type'
470 * It will return <= 0 if not all data has been sent or non-blocking IO.
471 */
472 int
ssl3_write_bytes(SSL * s,int type,const void * buf_,int len)473 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
474 {
475 const unsigned char *buf = buf_;
476 unsigned int tot, n, nw;
477 int i;
478
479 if (len < 0) {
480 SSLerror(s, ERR_R_INTERNAL_ERROR);
481 return -1;
482 }
483
484 s->internal->rwstate = SSL_NOTHING;
485 tot = S3I(s)->wnum;
486 S3I(s)->wnum = 0;
487
488 if (SSL_in_init(s) && !s->internal->in_handshake) {
489 i = s->internal->handshake_func(s);
490 if (i < 0)
491 return (i);
492 if (i == 0) {
493 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
494 return -1;
495 }
496 }
497
498 if (len < tot)
499 len = tot;
500 n = (len - tot);
501 for (;;) {
502 if (n > s->max_send_fragment)
503 nw = s->max_send_fragment;
504 else
505 nw = n;
506
507 i = do_ssl3_write(s, type, &(buf[tot]), nw);
508 if (i <= 0) {
509 S3I(s)->wnum = tot;
510 return i;
511 }
512
513 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA &&
514 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
515 /*
516 * Next chunk of data should get another prepended
517 * empty fragment in ciphersuites with known-IV
518 * weakness.
519 */
520 S3I(s)->empty_fragment_done = 0;
521
522 return tot + i;
523 }
524
525 n -= i;
526 tot += i;
527 }
528 }
529
530 static int
do_ssl3_write(SSL * s,int type,const unsigned char * buf,unsigned int len)531 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
532 {
533 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf);
534 SSL_SESSION *sess = s->session;
535 int need_empty_fragment = 0;
536 size_t align, out_len;
537 uint16_t version;
538 CBB cbb;
539 int ret;
540
541 memset(&cbb, 0, sizeof(cbb));
542
543 if (wb->buf == NULL)
544 if (!ssl3_setup_write_buffer(s))
545 return -1;
546
547 /*
548 * First check if there is a SSL3_BUFFER_INTERNAL still being written
549 * out. This will happen with non blocking IO.
550 */
551 if (wb->left != 0)
552 return (ssl3_write_pending(s, type, buf, len));
553
554 /* If we have an alert to send, let's send it. */
555 if (S3I(s)->alert_dispatch) {
556 if ((ret = ssl3_dispatch_alert(s)) <= 0)
557 return (ret);
558 /* If it went, fall through and send more stuff. */
559
560 /* We may have released our buffer, if so get it again. */
561 if (wb->buf == NULL)
562 if (!ssl3_setup_write_buffer(s))
563 return -1;
564 }
565
566 if (len == 0)
567 return 0;
568
569 /*
570 * Some servers hang if initial client hello is larger than 256
571 * bytes and record version number > TLS 1.0.
572 */
573 version = s->version;
574 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B &&
575 !s->internal->renegotiate &&
576 S3I(s)->hs.our_max_tls_version > TLS1_VERSION)
577 version = TLS1_VERSION;
578
579 /*
580 * Countermeasure against known-IV weakness in CBC ciphersuites
581 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this
582 * is unnecessary for AEAD.
583 */
584 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) {
585 if (S3I(s)->need_empty_fragments &&
586 !S3I(s)->empty_fragment_done &&
587 type == SSL3_RT_APPLICATION_DATA)
588 need_empty_fragment = 1;
589 }
590
591 /*
592 * An extra fragment would be a couple of cipher blocks, which would
593 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real
594 * payload, then we can just simply pretend we have two headers.
595 */
596 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH;
597 if (need_empty_fragment)
598 align += SSL3_RT_HEADER_LENGTH;
599 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);
600 wb->offset = align;
601
602 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align))
603 goto err;
604
605 tls12_record_layer_set_version(s->internal->rl, version);
606
607 if (need_empty_fragment) {
608 if (!tls12_record_layer_seal_record(s->internal->rl, type,
609 buf, 0, &cbb))
610 goto err;
611 S3I(s)->empty_fragment_done = 1;
612 }
613
614 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb))
615 goto err;
616
617 if (!CBB_finish(&cbb, NULL, &out_len))
618 goto err;
619
620 wb->left = out_len;
621
622 /*
623 * Memorize arguments so that ssl3_write_pending can detect
624 * bad write retries later.
625 */
626 S3I(s)->wpend_tot = len;
627 S3I(s)->wpend_buf = buf;
628 S3I(s)->wpend_type = type;
629 S3I(s)->wpend_ret = len;
630
631 /* We now just need to write the buffer. */
632 return ssl3_write_pending(s, type, buf, len);
633
634 err:
635 CBB_cleanup(&cbb);
636
637 return -1;
638 }
639
640 /* if S3I(s)->wbuf.left != 0, we need to call this */
641 int
ssl3_write_pending(SSL * s,int type,const unsigned char * buf,unsigned int len)642 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len)
643 {
644 int i;
645 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf);
646
647 /* XXXX */
648 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) &&
649 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
650 (S3I(s)->wpend_type != type)) {
651 SSLerror(s, SSL_R_BAD_WRITE_RETRY);
652 return (-1);
653 }
654
655 for (;;) {
656 errno = 0;
657 if (s->wbio != NULL) {
658 s->internal->rwstate = SSL_WRITING;
659 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]),
660 (unsigned int)wb->left);
661 } else {
662 SSLerror(s, SSL_R_BIO_NOT_SET);
663 i = -1;
664 }
665 if (i == wb->left) {
666 wb->left = 0;
667 wb->offset += i;
668 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
669 !SSL_is_dtls(s))
670 ssl3_release_write_buffer(s);
671 s->internal->rwstate = SSL_NOTHING;
672 return (S3I(s)->wpend_ret);
673 } else if (i <= 0) {
674 /*
675 * For DTLS, just drop it. That's kind of the
676 * whole point in using a datagram service.
677 */
678 if (SSL_is_dtls(s))
679 wb->left = 0;
680 return (i);
681 }
682 wb->offset += i;
683 wb->left -= i;
684 }
685 }
686
687 /* Return up to 'len' payload bytes received in 'type' records.
688 * 'type' is one of the following:
689 *
690 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
691 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
692 * - 0 (during a shutdown, no data has to be returned)
693 *
694 * If we don't have stored data to work from, read a SSL/TLS record first
695 * (possibly multiple records if we still don't have anything to return).
696 *
697 * This function must handle any surprises the peer may have for us, such as
698 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
699 * a surprise, but handled as if it were), or renegotiation requests.
700 * Also if record payloads contain fragments too small to process, we store
701 * them until there is enough for the respective protocol (the record protocol
702 * may use arbitrary fragmentation and even interleaving):
703 * Change cipher spec protocol
704 * just 1 byte needed, no need for keeping anything stored
705 * Alert protocol
706 * 2 bytes needed (AlertLevel, AlertDescription)
707 * Handshake protocol
708 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
709 * to detect unexpected Client Hello and Hello Request messages
710 * here, anything else is handled by higher layers
711 * Application data protocol
712 * none of our business
713 */
714 int
ssl3_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)715 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
716 {
717 int al, i, ret, rrcount = 0;
718 unsigned int n;
719 SSL3_RECORD_INTERNAL *rr;
720
721 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */
722 if (!ssl3_setup_read_buffer(s))
723 return (-1);
724
725 if (len < 0) {
726 SSLerror(s, ERR_R_INTERNAL_ERROR);
727 return -1;
728 }
729
730 if ((type && type != SSL3_RT_APPLICATION_DATA &&
731 type != SSL3_RT_HANDSHAKE) ||
732 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
733 SSLerror(s, ERR_R_INTERNAL_ERROR);
734 return -1;
735 }
736
737 if ((type == SSL3_RT_HANDSHAKE) &&
738 (S3I(s)->handshake_fragment_len > 0)) {
739 /* (partially) satisfy request from storage */
740 unsigned char *src = S3I(s)->handshake_fragment;
741 unsigned char *dst = buf;
742 unsigned int k;
743
744 /* peek == 0 */
745 n = 0;
746 while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) {
747 *dst++ = *src++;
748 len--;
749 S3I(s)->handshake_fragment_len--;
750 n++;
751 }
752 /* move any remaining fragment bytes: */
753 for (k = 0; k < S3I(s)->handshake_fragment_len; k++)
754 S3I(s)->handshake_fragment[k] = *src++;
755 return n;
756 }
757
758 /*
759 * Now S3I(s)->handshake_fragment_len == 0 if
760 * type == SSL3_RT_HANDSHAKE.
761 */
762 if (!s->internal->in_handshake && SSL_in_init(s)) {
763 /* type == SSL3_RT_APPLICATION_DATA */
764 i = s->internal->handshake_func(s);
765 if (i < 0)
766 return (i);
767 if (i == 0) {
768 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
769 return (-1);
770 }
771 }
772
773 start:
774 /*
775 * Do not process more than three consecutive records, otherwise the
776 * peer can cause us to loop indefinitely. Instead, return with an
777 * SSL_ERROR_WANT_READ so the caller can choose when to handle further
778 * processing. In the future, the total number of non-handshake and
779 * non-application data records per connection should probably also be
780 * limited...
781 */
782 if (rrcount++ >= 3) {
783 ssl_force_want_read(s);
784 return -1;
785 }
786
787 s->internal->rwstate = SSL_NOTHING;
788
789 /*
790 * S3I(s)->rrec.type - is the type of record
791 * S3I(s)->rrec.data, - data
792 * S3I(s)->rrec.off, - offset into 'data' for next read
793 * S3I(s)->rrec.length, - number of bytes.
794 */
795 rr = &(S3I(s)->rrec);
796
797 /* get new packet if necessary */
798 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) {
799 ret = ssl3_get_record(s);
800 if (ret <= 0)
801 return (ret);
802 }
803
804 /* we now have a packet which can be read and processed */
805
806 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec,
807 * reset by ssl3_get_finished */
808 && (rr->type != SSL3_RT_HANDSHAKE)) {
809 al = SSL_AD_UNEXPECTED_MESSAGE;
810 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
811 goto fatal_err;
812 }
813
814 /* If the other end has shut down, throw anything we read away
815 * (even in 'peek' mode) */
816 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) {
817 rr->length = 0;
818 s->internal->rwstate = SSL_NOTHING;
819 return (0);
820 }
821
822
823 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
824 if (type == rr->type) {
825 /* make sure that we are not getting application data when we
826 * are doing a handshake for the first time */
827 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
828 !tls12_record_layer_read_protected(s->internal->rl)) {
829 al = SSL_AD_UNEXPECTED_MESSAGE;
830 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE);
831 goto fatal_err;
832 }
833
834 if (len <= 0)
835 return (len);
836
837 if ((unsigned int)len > rr->length)
838 n = rr->length;
839 else
840 n = (unsigned int)len;
841
842 memcpy(buf, &(rr->data[rr->off]), n);
843 if (!peek) {
844 memset(&(rr->data[rr->off]), 0, n);
845 rr->length -= n;
846 rr->off += n;
847 if (rr->length == 0) {
848 s->internal->rstate = SSL_ST_READ_HEADER;
849 rr->off = 0;
850 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
851 S3I(s)->rbuf.left == 0)
852 ssl3_release_read_buffer(s);
853 }
854 }
855 return (n);
856 }
857
858
859 /* If we get here, then type != rr->type; if we have a handshake
860 * message, then it was unexpected (Hello Request or Client Hello). */
861
862 {
863 /*
864 * In case of record types for which we have 'fragment'
865 * storage, * fill that so that we can process the data
866 * at a fixed place.
867 */
868 unsigned int dest_maxlen = 0;
869 unsigned char *dest = NULL;
870 unsigned int *dest_len = NULL;
871
872 if (rr->type == SSL3_RT_HANDSHAKE) {
873 dest_maxlen = sizeof S3I(s)->handshake_fragment;
874 dest = S3I(s)->handshake_fragment;
875 dest_len = &S3I(s)->handshake_fragment_len;
876 } else if (rr->type == SSL3_RT_ALERT) {
877 dest_maxlen = sizeof S3I(s)->alert_fragment;
878 dest = S3I(s)->alert_fragment;
879 dest_len = &S3I(s)->alert_fragment_len;
880 }
881 if (dest_maxlen > 0) {
882 /* available space in 'dest' */
883 n = dest_maxlen - *dest_len;
884 if (rr->length < n)
885 n = rr->length; /* available bytes */
886
887 /* now move 'n' bytes: */
888 while (n-- > 0) {
889 dest[(*dest_len)++] = rr->data[rr->off++];
890 rr->length--;
891 }
892
893 if (*dest_len < dest_maxlen)
894 goto start; /* fragment was too small */
895 }
896 }
897
898 /* S3I(s)->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE;
899 * S3I(s)->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT.
900 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
901
902 /* If we are a client, check for an incoming 'Hello Request': */
903 if ((!s->server) && (S3I(s)->handshake_fragment_len >= 4) &&
904 (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
905 (s->session != NULL) && (s->session->cipher != NULL)) {
906 S3I(s)->handshake_fragment_len = 0;
907
908 if ((S3I(s)->handshake_fragment[1] != 0) ||
909 (S3I(s)->handshake_fragment[2] != 0) ||
910 (S3I(s)->handshake_fragment[3] != 0)) {
911 al = SSL_AD_DECODE_ERROR;
912 SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
913 goto fatal_err;
914 }
915
916 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE,
917 S3I(s)->handshake_fragment, 4);
918
919 if (SSL_is_init_finished(s) &&
920 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
921 !S3I(s)->renegotiate) {
922 ssl3_renegotiate(s);
923 if (ssl3_renegotiate_check(s)) {
924 i = s->internal->handshake_func(s);
925 if (i < 0)
926 return (i);
927 if (i == 0) {
928 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
929 return (-1);
930 }
931
932 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
933 if (S3I(s)->rbuf.left == 0) {
934 /* no read-ahead left? */
935 /* In the case where we try to read application data,
936 * but we trigger an SSL handshake, we return -1 with
937 * the retry option set. Otherwise renegotiation may
938 * cause nasty problems in the blocking world */
939 ssl_force_want_read(s);
940 return (-1);
941 }
942 }
943 }
944 }
945 /* we either finished a handshake or ignored the request,
946 * now try again to obtain the (application) data we were asked for */
947 goto start;
948 }
949 /* Disallow client initiated renegotiation if configured. */
950 if (s->server && SSL_is_init_finished(s) &&
951 S3I(s)->handshake_fragment_len >= 4 &&
952 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO &&
953 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) {
954 al = SSL_AD_NO_RENEGOTIATION;
955 goto fatal_err;
956 }
957 /* If we are a server and get a client hello when renegotiation isn't
958 * allowed send back a no renegotiation alert and carry on.
959 * WARNING: experimental code, needs reviewing (steve)
960 */
961 if (s->server &&
962 SSL_is_init_finished(s) &&
963 !S3I(s)->send_connection_binding &&
964 (S3I(s)->handshake_fragment_len >= 4) &&
965 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
966 (s->session != NULL) && (s->session->cipher != NULL)) {
967 /*S3I(s)->handshake_fragment_len = 0;*/
968 rr->length = 0;
969 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
970 goto start;
971 }
972 if (S3I(s)->alert_fragment_len >= 2) {
973 int alert_level = S3I(s)->alert_fragment[0];
974 int alert_descr = S3I(s)->alert_fragment[1];
975
976 S3I(s)->alert_fragment_len = 0;
977
978 ssl_msg_callback(s, 0, SSL3_RT_ALERT,
979 S3I(s)->alert_fragment, 2);
980
981 ssl_info_callback(s, SSL_CB_READ_ALERT,
982 (alert_level << 8) | alert_descr);
983
984 if (alert_level == SSL3_AL_WARNING) {
985 S3I(s)->warn_alert = alert_descr;
986 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
987 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
988 return (0);
989 }
990 /* This is a warning but we receive it if we requested
991 * renegotiation and the peer denied it. Terminate with
992 * a fatal alert because if application tried to
993 * renegotiatie it presumably had a good reason and
994 * expects it to succeed.
995 *
996 * In future we might have a renegotiation where we
997 * don't care if the peer refused it where we carry on.
998 */
999 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
1000 al = SSL_AD_HANDSHAKE_FAILURE;
1001 SSLerror(s, SSL_R_NO_RENEGOTIATION);
1002 goto fatal_err;
1003 }
1004 } else if (alert_level == SSL3_AL_FATAL) {
1005 s->internal->rwstate = SSL_NOTHING;
1006 S3I(s)->fatal_alert = alert_descr;
1007 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
1008 ERR_asprintf_error_data("SSL alert number %d",
1009 alert_descr);
1010 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
1011 SSL_CTX_remove_session(s->ctx, s->session);
1012 return (0);
1013 } else {
1014 al = SSL_AD_ILLEGAL_PARAMETER;
1015 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
1016 goto fatal_err;
1017 }
1018
1019 goto start;
1020 }
1021
1022 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) {
1023 /* but we have not received a shutdown */
1024 s->internal->rwstate = SSL_NOTHING;
1025 rr->length = 0;
1026 return (0);
1027 }
1028
1029 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1030 /* 'Change Cipher Spec' is just a single byte, so we know
1031 * exactly what the record payload has to look like */
1032 if ((rr->length != 1) || (rr->off != 0) ||
1033 (rr->data[0] != SSL3_MT_CCS)) {
1034 al = SSL_AD_ILLEGAL_PARAMETER;
1035 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
1036 goto fatal_err;
1037 }
1038
1039 /* Check we have a cipher to change to */
1040 if (S3I(s)->hs.cipher == NULL) {
1041 al = SSL_AD_UNEXPECTED_MESSAGE;
1042 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1043 goto fatal_err;
1044 }
1045
1046 /* Check that we should be receiving a Change Cipher Spec. */
1047 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) {
1048 al = SSL_AD_UNEXPECTED_MESSAGE;
1049 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1050 goto fatal_err;
1051 }
1052 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
1053
1054 rr->length = 0;
1055
1056 ssl_msg_callback(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1);
1057
1058 S3I(s)->change_cipher_spec = 1;
1059 if (!ssl3_do_change_cipher_spec(s))
1060 goto err;
1061 else
1062 goto start;
1063 }
1064
1065 /* Unexpected handshake message (Client Hello, or protocol violation) */
1066 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) {
1067 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) &&
1068 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1069 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1070 s->internal->renegotiate = 1;
1071 s->internal->new_session = 1;
1072 }
1073 i = s->internal->handshake_func(s);
1074 if (i < 0)
1075 return (i);
1076 if (i == 0) {
1077 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
1078 return (-1);
1079 }
1080
1081 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
1082 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */
1083 /* In the case where we try to read application data,
1084 * but we trigger an SSL handshake, we return -1 with
1085 * the retry option set. Otherwise renegotiation may
1086 * cause nasty problems in the blocking world */
1087 ssl_force_want_read(s);
1088 return (-1);
1089 }
1090 }
1091 goto start;
1092 }
1093
1094 switch (rr->type) {
1095 default:
1096 /*
1097 * TLS up to v1.1 just ignores unknown message types:
1098 * TLS v1.2 give an unexpected message alert.
1099 */
1100 if (s->version >= TLS1_VERSION &&
1101 s->version <= TLS1_1_VERSION) {
1102 rr->length = 0;
1103 goto start;
1104 }
1105 al = SSL_AD_UNEXPECTED_MESSAGE;
1106 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1107 goto fatal_err;
1108 case SSL3_RT_CHANGE_CIPHER_SPEC:
1109 case SSL3_RT_ALERT:
1110 case SSL3_RT_HANDSHAKE:
1111 /* we already handled all of these, with the possible exception
1112 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that
1113 * should not happen when type != rr->type */
1114 al = SSL_AD_UNEXPECTED_MESSAGE;
1115 SSLerror(s, ERR_R_INTERNAL_ERROR);
1116 goto fatal_err;
1117 case SSL3_RT_APPLICATION_DATA:
1118 /* At this point, we were expecting handshake data,
1119 * but have application data. If the library was
1120 * running inside ssl3_read() (i.e. in_read_app_data
1121 * is set) and it makes sense to read application data
1122 * at this point (session renegotiation not yet started),
1123 * we will indulge it.
1124 */
1125 if (S3I(s)->in_read_app_data &&
1126 (S3I(s)->total_renegotiations != 0) &&
1127 (((S3I(s)->hs.state & SSL_ST_CONNECT) &&
1128 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1129 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) ||
1130 ((S3I(s)->hs.state & SSL_ST_ACCEPT) &&
1131 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
1132 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
1133 S3I(s)->in_read_app_data = 2;
1134 return (-1);
1135 } else {
1136 al = SSL_AD_UNEXPECTED_MESSAGE;
1137 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1138 goto fatal_err;
1139 }
1140 }
1141 /* not reached */
1142
1143 fatal_err:
1144 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1145 err:
1146 return (-1);
1147 }
1148
1149 int
ssl3_do_change_cipher_spec(SSL * s)1150 ssl3_do_change_cipher_spec(SSL *s)
1151 {
1152 if (S3I(s)->hs.tls12.key_block == NULL) {
1153 if (s->session == NULL || s->session->master_key_length == 0) {
1154 /* might happen if dtls1_read_bytes() calls this */
1155 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
1156 return (0);
1157 }
1158
1159 s->session->cipher = S3I(s)->hs.cipher;
1160 if (!tls1_setup_key_block(s))
1161 return (0);
1162 }
1163
1164 if (!tls1_change_read_cipher_state(s))
1165 return (0);
1166
1167 /*
1168 * We have to record the message digest at this point so we can get it
1169 * before we read the finished message.
1170 */
1171 if (!tls12_derive_peer_finished(s))
1172 return (0);
1173
1174 return (1);
1175 }
1176
1177 static int
ssl3_write_alert(SSL * s)1178 ssl3_write_alert(SSL *s)
1179 {
1180 if (SSL_is_dtls(s))
1181 return do_dtls1_write(s, SSL3_RT_ALERT, S3I(s)->send_alert,
1182 sizeof(S3I(s)->send_alert));
1183
1184 return do_ssl3_write(s, SSL3_RT_ALERT, S3I(s)->send_alert,
1185 sizeof(S3I(s)->send_alert));
1186 }
1187
1188 int
ssl3_send_alert(SSL * s,int level,int desc)1189 ssl3_send_alert(SSL *s, int level, int desc)
1190 {
1191 /* If alert is fatal, remove session from cache. */
1192 if (level == SSL3_AL_FATAL)
1193 SSL_CTX_remove_session(s->ctx, s->session);
1194
1195 S3I(s)->alert_dispatch = 1;
1196 S3I(s)->send_alert[0] = level;
1197 S3I(s)->send_alert[1] = desc;
1198
1199 /*
1200 * If data is still being written out, the alert will be dispatched at
1201 * some point in the future.
1202 */
1203 if (S3I(s)->wbuf.left != 0)
1204 return -1;
1205
1206 return ssl3_dispatch_alert(s);
1207 }
1208
1209 int
ssl3_dispatch_alert(SSL * s)1210 ssl3_dispatch_alert(SSL *s)
1211 {
1212 int ret;
1213
1214 S3I(s)->alert_dispatch = 0;
1215 if ((ret = ssl3_write_alert(s)) <= 0) {
1216 S3I(s)->alert_dispatch = 1;
1217 return ret;
1218 }
1219
1220 /*
1221 * Alert sent to BIO. If it is important, flush it now.
1222 * If the message does not get sent due to non-blocking IO,
1223 * we will not worry too much.
1224 */
1225 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL)
1226 (void)BIO_flush(s->wbio);
1227
1228 ssl_msg_callback(s, 1, SSL3_RT_ALERT, S3I(s)->send_alert, 2);
1229
1230 ssl_info_callback(s, SSL_CB_WRITE_ALERT,
1231 (S3I(s)->send_alert[0] << 8) | S3I(s)->send_alert[1]);
1232
1233 return ret;
1234 }
1235