2 * Copyright 2005-2022 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
13 #include "../ssl_local.h"
14 #include "statem_local.h"
15 #include "internal/cryptlib.h"
16 #include <openssl/buffer.h>
17 #include <openssl/objects.h>
18 #include <openssl/evp.h>
19 #include <openssl/x509.h>
21 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
23 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
24 if ((end) - (start) <= 8) { \
26 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
29 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
30 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
31 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
34 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
37 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
38 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
39 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
41 static unsigned char bitmask_start_values[] =
42 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
43 static unsigned char bitmask_end_values[] =
44 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
46 static void dtls1_fix_message_header(SSL *s, size_t frag_off,
48 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
49 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
51 unsigned short seq_num,
54 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len);
56 static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly)
58 hm_fragment *frag = NULL;
59 unsigned char *buf = NULL;
60 unsigned char *bitmask = NULL;
62 if ((frag = OPENSSL_malloc(sizeof(*frag))) == NULL) {
63 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
68 if ((buf = OPENSSL_malloc(frag_len)) == NULL) {
69 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
75 /* zero length fragment gets zero frag->fragment */
78 /* Initialize reassembly bitmask if necessary */
80 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
81 if (bitmask == NULL) {
82 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
89 frag->reassembly = bitmask;
94 void dtls1_hm_fragment_free(hm_fragment *frag)
98 if (frag->msg_header.is_ccs) {
99 EVP_CIPHER_CTX_free(frag->msg_header.
100 saved_retransmit_state.enc_write_ctx);
101 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
103 OPENSSL_free(frag->fragment);
104 OPENSSL_free(frag->reassembly);
109 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
110 * SSL3_RT_CHANGE_CIPHER_SPEC)
112 int dtls1_do_write(SSL *s, int type)
118 size_t len, frag_off, mac_size, blocksize, used_len;
120 if (!dtls1_query_mtu(s))
123 if (s->d1->mtu < dtls1_min_mtu(s))
124 /* should have something reasonable now */
127 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
128 if (!ossl_assert(s->init_num ==
129 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH))
135 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx)) &
136 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
139 mac_size = EVP_MD_CTX_get_size(s->write_hash);
143 if (s->enc_write_ctx &&
144 (EVP_CIPHER_CTX_get_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
145 blocksize = 2 * EVP_CIPHER_CTX_get_block_size(s->enc_write_ctx);
150 s->rwstate = SSL_NOTHING;
152 /* s->init_num shouldn't ever be < 0...but just in case */
153 while (s->init_num > 0) {
154 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
155 /* We must be writing a fragment other than the first one */
158 /* This is the first attempt at writing out this fragment */
160 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
162 * Each fragment that was already sent must at least have
163 * contained the message header plus one other byte.
164 * Therefore |init_off| must have progressed by at least
165 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
172 * Adjust |init_off| and |init_num| to allow room for a new
173 * message header for this fragment.
175 s->init_off -= DTLS1_HM_HEADER_LENGTH;
176 s->init_num += DTLS1_HM_HEADER_LENGTH;
179 * We must have been called again after a retry so use the
180 * fragment offset from our last attempt. We do not need
181 * to adjust |init_off| and |init_num| as above, because
182 * that should already have been done before the retry.
184 frag_off = s->d1->w_msg_hdr.frag_off;
188 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
189 + mac_size + blocksize;
190 if (s->d1->mtu > used_len)
191 curr_mtu = s->d1->mtu - used_len;
195 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
197 * grr.. we could get an error if MTU picked was wrong
199 ret = BIO_flush(s->wbio);
201 s->rwstate = SSL_WRITING;
204 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
205 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
206 curr_mtu = s->d1->mtu - used_len;
208 /* Shouldn't happen */
214 * We just checked that s->init_num > 0 so this cast should be safe
216 if (((unsigned int)s->init_num) > curr_mtu)
221 if (len > ssl_get_max_send_fragment(s))
222 len = ssl_get_max_send_fragment(s);
225 * XDTLS: this function is too long. split out the CCS part
227 if (type == SSL3_RT_HANDSHAKE) {
228 if (len < DTLS1_HM_HEADER_LENGTH) {
230 * len is so small that we really can't do anything sensible
235 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
237 dtls1_write_message_header(s,
238 (unsigned char *)&s->init_buf->
242 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
246 * might need to update MTU here, but we don't know which
247 * previous packet caused the failure -- so can't really
248 * retransmit anything. continue as if everything is fine and
249 * wait for an alert to handle the retransmit
251 if (retry && BIO_ctrl(SSL_get_wbio(s),
252 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
253 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
254 if (!dtls1_query_mtu(s))
256 /* Have one more go */
266 * bad if this assert fails, only part of the handshake message
267 * got sent. but why would this happen?
269 if (!ossl_assert(len == written))
272 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
274 * should not be done for 'Hello Request's, but in that case
275 * we'll ignore the result anyway
278 (unsigned char *)&s->init_buf->data[s->init_off];
279 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
282 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
284 * reconstruct message header is if it is being sent in
287 *p++ = msg_hdr->type;
288 l2n3(msg_hdr->msg_len, p);
289 s2n(msg_hdr->seq, p);
291 l2n3(msg_hdr->msg_len, p);
292 p -= DTLS1_HM_HEADER_LENGTH;
295 p += DTLS1_HM_HEADER_LENGTH;
296 xlen = written - DTLS1_HM_HEADER_LENGTH;
299 if (!ssl3_finish_mac(s, p, xlen))
303 if (written == s->init_num) {
305 s->msg_callback(1, s->version, type, s->init_buf->data,
306 (size_t)(s->init_off + s->init_num), s,
307 s->msg_callback_arg);
309 s->init_off = 0; /* done writing this message */
314 s->init_off += written;
315 s->init_num -= written;
316 written -= DTLS1_HM_HEADER_LENGTH;
320 * We save the fragment offset for the next fragment so we have it
321 * available in case of an IO retry. We don't know the length of the
322 * next fragment yet so just set that to 0 for now. It will be
323 * updated again later.
325 dtls1_fix_message_header(s, frag_off, 0);
331 int dtls_get_message(SSL *s, int *mt)
333 struct hm_header_st *msg_hdr;
339 msg_hdr = &s->d1->r_msg_hdr;
340 memset(msg_hdr, 0, sizeof(*msg_hdr));
343 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
344 if (errtype == DTLS1_HM_BAD_FRAGMENT
345 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
346 /* bad fragment received */
352 *mt = s->s3.tmp.message_type;
354 p = (unsigned char *)s->init_buf->data;
356 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
357 if (s->msg_callback) {
358 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
359 p, 1, s, s->msg_callback_arg);
362 * This isn't a real handshake message so skip the processing below.
367 msg_len = msg_hdr->msg_len;
369 /* reconstruct message header */
370 *(p++) = msg_hdr->type;
372 s2n(msg_hdr->seq, p);
376 memset(msg_hdr, 0, sizeof(*msg_hdr));
378 s->d1->handshake_read_seq++;
380 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
386 * Actually we already have the message body - but this is an opportunity for
387 * DTLS to do any further processing it wants at the same point that TLS would
388 * be asked for the message body.
390 int dtls_get_message_body(SSL *s, size_t *len)
392 unsigned char *msg = (unsigned char *)s->init_buf->data;
393 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH;
395 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
396 /* Nothing to be done */
400 * If receiving Finished, record MAC of prior handshake messages for
401 * Finished verification.
403 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) {
404 /* SSLfatal() already called */
408 if (s->version == DTLS1_BAD_VER) {
409 msg += DTLS1_HM_HEADER_LENGTH;
410 msg_len -= DTLS1_HM_HEADER_LENGTH;
413 if (!ssl3_finish_mac(s, msg, msg_len))
417 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
418 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH,
419 s, s->msg_callback_arg);
427 * dtls1_max_handshake_message_len returns the maximum number of bytes
428 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
429 * may be greater if the maximum certificate list size requires it.
431 static size_t dtls1_max_handshake_message_len(const SSL *s)
433 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
434 if (max_len < s->max_cert_list)
435 return s->max_cert_list;
439 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
441 size_t frag_off, frag_len, msg_len;
443 msg_len = msg_hdr->msg_len;
444 frag_off = msg_hdr->frag_off;
445 frag_len = msg_hdr->frag_len;
447 /* sanity checking */
448 if ((frag_off + frag_len) > msg_len
449 || msg_len > dtls1_max_handshake_message_len(s)) {
450 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
454 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
456 * msg_len is limited to 2^24, but is effectively checked against
457 * dtls_max_handshake_message_len(s) above
459 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
460 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
464 s->s3.tmp.message_size = msg_len;
465 s->d1->r_msg_hdr.msg_len = msg_len;
466 s->s3.tmp.message_type = msg_hdr->type;
467 s->d1->r_msg_hdr.type = msg_hdr->type;
468 s->d1->r_msg_hdr.seq = msg_hdr->seq;
469 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
471 * They must be playing with us! BTW, failure to enforce upper limit
472 * would open possibility for buffer overrun.
474 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
482 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
485 static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len)
488 * (0) check whether the desired fragment is available
490 * (1) copy over the fragment to s->init_buf->data[]
491 * (2) update s->init_num
498 item = pqueue_peek(s->d1->buffered_messages);
502 frag = (hm_fragment *)item->data;
504 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
505 /* This is a stale message that has been buffered so clear it */
506 pqueue_pop(s->d1->buffered_messages);
507 dtls1_hm_fragment_free(frag);
512 } while (item == NULL);
514 /* Don't return if reassembly still in progress */
515 if (frag->reassembly != NULL)
518 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
519 size_t frag_len = frag->msg_header.frag_len;
520 pqueue_pop(s->d1->buffered_messages);
522 /* Calls SSLfatal() as required */
523 ret = dtls1_preprocess_fragment(s, &frag->msg_header);
525 if (ret && frag->msg_header.frag_len > 0) {
527 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
528 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
529 frag->msg_header.frag_len);
532 dtls1_hm_fragment_free(frag);
549 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr)
551 hm_fragment *frag = NULL;
553 int i = -1, is_complete;
554 unsigned char seq64be[8];
555 size_t frag_len = msg_hdr->frag_len;
558 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
559 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
563 return DTLS1_HM_FRAGMENT_RETRY;
566 /* Try to find item in queue */
567 memset(seq64be, 0, sizeof(seq64be));
568 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
569 seq64be[7] = (unsigned char)msg_hdr->seq;
570 item = pqueue_find(s->d1->buffered_messages, seq64be);
573 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
576 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
577 frag->msg_header.frag_len = frag->msg_header.msg_len;
578 frag->msg_header.frag_off = 0;
580 frag = (hm_fragment *)item->data;
581 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
589 * If message is already reassembled, this must be a retransmit and can
590 * be dropped. In this case item != NULL and so frag does not need to be
593 if (frag->reassembly == NULL) {
594 unsigned char devnull[256];
597 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
600 sizeof(devnull) ? sizeof(devnull) :
601 frag_len, 0, &readbytes);
604 frag_len -= readbytes;
606 return DTLS1_HM_FRAGMENT_RETRY;
609 /* read the body of the fragment (header has already been read */
610 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
611 frag->fragment + msg_hdr->frag_off,
612 frag_len, 0, &readbytes);
613 if (i <= 0 || readbytes != frag_len)
618 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
619 (long)(msg_hdr->frag_off + frag_len));
621 if (!ossl_assert(msg_hdr->msg_len > 0))
623 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
627 OPENSSL_free(frag->reassembly);
628 frag->reassembly = NULL;
632 item = pitem_new(seq64be, frag);
638 item = pqueue_insert(s->d1->buffered_messages, item);
640 * pqueue_insert fails iff a duplicate item is inserted. However,
641 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
642 * would have returned it and control would never have reached this
645 if (!ossl_assert(item != NULL))
649 return DTLS1_HM_FRAGMENT_RETRY;
653 dtls1_hm_fragment_free(frag);
658 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr)
661 hm_fragment *frag = NULL;
663 unsigned char seq64be[8];
664 size_t frag_len = msg_hdr->frag_len;
667 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
670 /* Try to find item in queue, to prevent duplicate entries */
671 memset(seq64be, 0, sizeof(seq64be));
672 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
673 seq64be[7] = (unsigned char)msg_hdr->seq;
674 item = pqueue_find(s->d1->buffered_messages, seq64be);
677 * If we already have an entry and this one is a fragment, don't discard
678 * it and rather try to reassemble it.
680 if (item != NULL && frag_len != msg_hdr->msg_len)
684 * Discard the message if sequence number was already there, is too far
685 * in the future, already in the queue or if we received a FINISHED
686 * before the SERVER_HELLO, which then must be a stale retransmit.
688 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
689 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
690 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
691 unsigned char devnull[256];
694 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
697 sizeof(devnull) ? sizeof(devnull) :
698 frag_len, 0, &readbytes);
701 frag_len -= readbytes;
704 if (frag_len != msg_hdr->msg_len) {
705 return dtls1_reassemble_fragment(s, msg_hdr);
708 if (frag_len > dtls1_max_handshake_message_len(s))
711 frag = dtls1_hm_fragment_new(frag_len, 0);
715 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
719 * read the body of the fragment (header has already been read
721 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
722 frag->fragment, frag_len, 0,
724 if (i<=0 || readbytes != frag_len)
730 item = pitem_new(seq64be, frag);
734 item = pqueue_insert(s->d1->buffered_messages, item);
736 * pqueue_insert fails iff a duplicate item is inserted. However,
737 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
738 * would have returned it. Then, either |frag_len| !=
739 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
740 * have been processed with |dtls1_reassemble_fragment|, above, or
741 * the record will have been discarded.
743 if (!ossl_assert(item != NULL))
747 return DTLS1_HM_FRAGMENT_RETRY;
751 dtls1_hm_fragment_free(frag);
755 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len)
757 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
758 size_t mlen, frag_off, frag_len;
759 int i, ret, recvd_type;
760 struct hm_header_st msg_hdr;
766 /* see if we have the required fragment already */
767 ret = dtls1_retrieve_buffered_fragment(s, &frag_len);
769 /* SSLfatal() already called */
773 s->init_num = frag_len;
778 /* read handshake message header */
779 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
780 DTLS1_HM_HEADER_LENGTH, 0, &readbytes);
781 if (i <= 0) { /* nbio, or an error */
782 s->rwstate = SSL_READING;
786 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
787 if (wire[0] != SSL3_MT_CCS) {
788 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
789 SSL_R_BAD_CHANGE_CIPHER_SPEC);
793 memcpy(s->init_buf->data, wire, readbytes);
794 s->init_num = readbytes - 1;
795 s->init_msg = s->init_buf->data + 1;
796 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
797 s->s3.tmp.message_size = readbytes - 1;
798 *len = readbytes - 1;
802 /* Handshake fails if message header is incomplete */
803 if (readbytes != DTLS1_HM_HEADER_LENGTH) {
804 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
808 /* parse the message fragment header */
809 dtls1_get_message_header(wire, &msg_hdr);
811 mlen = msg_hdr.msg_len;
812 frag_off = msg_hdr.frag_off;
813 frag_len = msg_hdr.frag_len;
816 * We must have at least frag_len bytes left in the record to be read.
817 * Fragments must not span records.
819 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
820 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
825 * if this is a future (or stale) message it gets buffered
826 * (or dropped)--no further processing at this time
827 * While listening, we accept seq 1 (ClientHello with cookie)
828 * although we're still expecting seq 0 (ClientHello)
830 if (msg_hdr.seq != s->d1->handshake_read_seq) {
831 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
835 if (frag_len && frag_len < mlen) {
836 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
841 && s->d1->r_msg_hdr.frag_off == 0
842 && s->statem.hand_state != TLS_ST_OK
843 && wire[0] == SSL3_MT_HELLO_REQUEST) {
845 * The server may always send 'Hello Request' messages -- we are
846 * doing a handshake anyway now, so ignore them if their format is
847 * correct. Does not count for 'Finished' MAC.
849 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
851 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
852 wire, DTLS1_HM_HEADER_LENGTH, s,
853 s->msg_callback_arg);
857 } else { /* Incorrectly formatted Hello request */
859 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
864 if (!dtls1_preprocess_fragment(s, &msg_hdr)) {
865 /* SSLfatal() already called */
871 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
873 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
874 &p[frag_off], frag_len, 0, &readbytes);
877 * This shouldn't ever fail due to NBIO because we already checked
878 * that we have enough data in the record
881 s->rwstate = SSL_READING;
890 * XDTLS: an incorrectly formatted fragment should cause the handshake
893 if (readbytes != frag_len) {
894 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
899 * Note that s->init_num is *not* used as current offset in
900 * s->init_buf->data, but as a counter summing up fragments' lengths: as
901 * soon as they sum up to handshake packet length, we assume we have got
904 *len = s->init_num = frag_len;
914 * for these 2 messages, we need to
915 * ssl->enc_read_ctx re-init
916 * ssl->rlayer.read_sequence zero
917 * ssl->s3.read_mac_secret re-init
918 * ssl->session->read_sym_enc assign
919 * ssl->session->read_compression assign
920 * ssl->session->read_hash assign
922 int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
924 if (s->version == DTLS1_BAD_VER) {
925 s->d1->next_handshake_write_seq++;
927 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
928 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
936 #ifndef OPENSSL_NO_SCTP
938 * Wait for a dry event. Should only be called at a point in the handshake
939 * where we are not expecting any data from the peer except an alert.
941 WORK_STATE dtls_wait_for_dry(SSL *s)
946 /* read app data until dry event */
947 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
949 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
955 * We're not expecting any more messages from the peer at this point -
956 * but we could get an alert. If an alert is waiting then we will never
957 * return successfully. Therefore we attempt to read a message. This
958 * should never succeed but will process any waiting alerts.
960 if (dtls_get_reassembled_message(s, &errtype, &len)) {
961 /* The call succeeded! This should never happen */
962 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
966 s->s3.in_read_app_data = 2;
967 s->rwstate = SSL_READING;
968 BIO_clear_retry_flags(SSL_get_rbio(s));
969 BIO_set_retry_read(SSL_get_rbio(s));
972 return WORK_FINISHED_CONTINUE;
976 int dtls1_read_failed(SSL *s, int code)
979 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
983 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) {
985 * not a timeout, none of our business, let higher layers handle
986 * this. in fact it's probably an error
990 /* done, no need to send a retransmit */
993 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
997 return dtls1_handle_timeout(s);
1000 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1003 * The index of the retransmission queue actually is the message sequence
1004 * number, since the queue only contains messages of a single handshake.
1005 * However, the ChangeCipherSpec has no message sequence number and so
1006 * using only the sequence will result in the CCS and Finished having the
1007 * same index. To prevent this, the sequence number is multiplied by 2.
1008 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1009 * Finished, it also maintains the order of the index (important for
1010 * priority queues) and fits in the unsigned short variable.
1012 return seq * 2 - is_ccs;
1015 int dtls1_retransmit_buffered_messages(SSL *s)
1017 pqueue *sent = s->d1->sent_messages;
1023 iter = pqueue_iterator(sent);
1025 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1026 frag = (hm_fragment *)item->data;
1027 if (dtls1_retransmit_message(s, (unsigned short)
1028 dtls1_get_queue_priority
1029 (frag->msg_header.seq,
1030 frag->msg_header.is_ccs), &found) <= 0)
1037 int dtls1_buffer_message(SSL *s, int is_ccs)
1041 unsigned char seq64be[8];
1044 * this function is called immediately after a message has been
1047 if (!ossl_assert(s->init_off == 0))
1050 frag = dtls1_hm_fragment_new(s->init_num, 0);
1054 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1057 /* For DTLS1_BAD_VER the header length is non-standard */
1058 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1060 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
1061 == (unsigned int)s->init_num)) {
1062 dtls1_hm_fragment_free(frag);
1066 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1067 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) {
1068 dtls1_hm_fragment_free(frag);
1073 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1074 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1075 frag->msg_header.type = s->d1->w_msg_hdr.type;
1076 frag->msg_header.frag_off = 0;
1077 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1078 frag->msg_header.is_ccs = is_ccs;
1080 /* save current state */
1081 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1082 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1083 frag->msg_header.saved_retransmit_state.compress = s->compress;
1084 frag->msg_header.saved_retransmit_state.session = s->session;
1085 frag->msg_header.saved_retransmit_state.epoch =
1086 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1088 memset(seq64be, 0, sizeof(seq64be));
1091 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1092 frag->msg_header.is_ccs) >> 8);
1095 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1096 frag->msg_header.is_ccs));
1098 item = pitem_new(seq64be, frag);
1100 dtls1_hm_fragment_free(frag);
1104 pqueue_insert(s->d1->sent_messages, item);
1108 int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1111 /* XDTLS: for now assuming that read/writes are blocking */
1114 unsigned long header_length;
1115 unsigned char seq64be[8];
1116 struct dtls1_retransmit_state saved_state;
1118 /* XDTLS: the requested message ought to be found, otherwise error */
1119 memset(seq64be, 0, sizeof(seq64be));
1120 seq64be[6] = (unsigned char)(seq >> 8);
1121 seq64be[7] = (unsigned char)seq;
1123 item = pqueue_find(s->d1->sent_messages, seq64be);
1125 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1131 frag = (hm_fragment *)item->data;
1133 if (frag->msg_header.is_ccs)
1134 header_length = DTLS1_CCS_HEADER_LENGTH;
1136 header_length = DTLS1_HM_HEADER_LENGTH;
1138 memcpy(s->init_buf->data, frag->fragment,
1139 frag->msg_header.msg_len + header_length);
1140 s->init_num = frag->msg_header.msg_len + header_length;
1142 dtls1_set_message_header_int(s, frag->msg_header.type,
1143 frag->msg_header.msg_len,
1144 frag->msg_header.seq, 0,
1145 frag->msg_header.frag_len);
1147 /* save current state */
1148 saved_state.enc_write_ctx = s->enc_write_ctx;
1149 saved_state.write_hash = s->write_hash;
1150 saved_state.compress = s->compress;
1151 saved_state.session = s->session;
1152 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1154 s->d1->retransmitting = 1;
1156 /* restore state in which the message was originally sent */
1157 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1158 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1159 s->compress = frag->msg_header.saved_retransmit_state.compress;
1160 s->session = frag->msg_header.saved_retransmit_state.session;
1161 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1163 saved_retransmit_state.epoch);
1165 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1166 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1168 /* restore current state */
1169 s->enc_write_ctx = saved_state.enc_write_ctx;
1170 s->write_hash = saved_state.write_hash;
1171 s->compress = saved_state.compress;
1172 s->session = saved_state.session;
1173 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1175 s->d1->retransmitting = 0;
1177 (void)BIO_flush(s->wbio);
1181 void dtls1_set_message_header(SSL *s,
1182 unsigned char mt, size_t len,
1183 size_t frag_off, size_t frag_len)
1185 if (frag_off == 0) {
1186 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1187 s->d1->next_handshake_write_seq++;
1190 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1191 frag_off, frag_len);
1194 /* don't actually do the writing, wait till the MTU has been retrieved */
1196 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1197 size_t len, unsigned short seq_num,
1198 size_t frag_off, size_t frag_len)
1200 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1203 msg_hdr->msg_len = len;
1204 msg_hdr->seq = seq_num;
1205 msg_hdr->frag_off = frag_off;
1206 msg_hdr->frag_len = frag_len;
1210 dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len)
1212 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1214 msg_hdr->frag_off = frag_off;
1215 msg_hdr->frag_len = frag_len;
1218 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1220 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1222 *p++ = msg_hdr->type;
1223 l2n3(msg_hdr->msg_len, p);
1225 s2n(msg_hdr->seq, p);
1226 l2n3(msg_hdr->frag_off, p);
1227 l2n3(msg_hdr->frag_len, p);
1232 void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1234 memset(msg_hdr, 0, sizeof(*msg_hdr));
1235 msg_hdr->type = *(data++);
1236 n2l3(data, msg_hdr->msg_len);
1238 n2s(data, msg_hdr->seq);
1239 n2l3(data, msg_hdr->frag_off);
1240 n2l3(data, msg_hdr->frag_len);
1243 int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype)
1245 unsigned char *header;
1247 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1248 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1249 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1250 s->d1->handshake_write_seq, 0, 0);
1251 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1254 dtls1_set_message_header(s, htype, 0, 0, 0);
1256 * We allocate space at the start for the message header. This gets
1259 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1260 || !WPACKET_start_sub_packet(pkt))
1267 int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
1271 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1272 || !WPACKET_get_length(pkt, &msglen)
1273 || msglen > INT_MAX)
1276 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1277 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1278 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1280 s->init_num = (int)msglen;
1283 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1284 /* Buffer the message to handle re-xmits */
1285 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC