2 * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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_locl.h"
14 #include "statem_locl.h"
15 #include <openssl/buffer.h>
16 #include <openssl/objects.h>
17 #include <openssl/evp.h>
18 #include <openssl/x509.h>
20 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
22 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
23 if ((end) - (start) <= 8) { \
25 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
28 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
29 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
30 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
33 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
36 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
37 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
38 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
40 static unsigned char bitmask_start_values[] =
41 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
42 static unsigned char bitmask_end_values[] =
43 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
45 static void dtls1_fix_message_header(SSL *s, size_t frag_off,
47 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
48 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
50 unsigned short seq_num,
53 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len);
55 static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly)
57 hm_fragment *frag = NULL;
58 unsigned char *buf = NULL;
59 unsigned char *bitmask = NULL;
61 frag = OPENSSL_malloc(sizeof(*frag));
66 buf = OPENSSL_malloc(frag_len);
73 /* zero length fragment gets zero frag->fragment */
76 /* Initialize reassembly bitmask if necessary */
78 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
79 if (bitmask == NULL) {
86 frag->reassembly = bitmask;
91 void dtls1_hm_fragment_free(hm_fragment *frag)
95 if (frag->msg_header.is_ccs) {
96 EVP_CIPHER_CTX_free(frag->msg_header.
97 saved_retransmit_state.enc_write_ctx);
98 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
100 OPENSSL_free(frag->fragment);
101 OPENSSL_free(frag->reassembly);
106 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
107 * SSL3_RT_CHANGE_CIPHER_SPEC)
109 int dtls1_do_write(SSL *s, int type)
115 size_t len, frag_off, mac_size, blocksize, used_len;
117 if (!dtls1_query_mtu(s))
120 if (s->d1->mtu < dtls1_min_mtu(s))
121 /* should have something reasonable now */
124 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
125 if (!ossl_assert(s->init_num ==
126 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH))
132 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_write_ctx)) &
133 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
136 mac_size = EVP_MD_CTX_size(s->write_hash);
140 if (s->enc_write_ctx &&
141 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
142 blocksize = 2 * EVP_CIPHER_CTX_block_size(s->enc_write_ctx);
147 s->rwstate = SSL_NOTHING;
149 /* s->init_num shouldn't ever be < 0...but just in case */
150 while (s->init_num > 0) {
151 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
152 /* We must be writing a fragment other than the first one */
155 /* This is the first attempt at writing out this fragment */
157 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
159 * Each fragment that was already sent must at least have
160 * contained the message header plus one other byte.
161 * Therefore |init_off| must have progressed by at least
162 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
169 * Adjust |init_off| and |init_num| to allow room for a new
170 * message header for this fragment.
172 s->init_off -= DTLS1_HM_HEADER_LENGTH;
173 s->init_num += DTLS1_HM_HEADER_LENGTH;
176 * We must have been called again after a retry so use the
177 * fragment offset from our last attempt. We do not need
178 * to adjust |init_off| and |init_num| as above, because
179 * that should already have been done before the retry.
181 frag_off = s->d1->w_msg_hdr.frag_off;
185 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
186 + mac_size + blocksize;
187 if (s->d1->mtu > used_len)
188 curr_mtu = s->d1->mtu - used_len;
192 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
194 * grr.. we could get an error if MTU picked was wrong
196 ret = BIO_flush(s->wbio);
198 s->rwstate = SSL_WRITING;
201 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
202 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
203 curr_mtu = s->d1->mtu - used_len;
205 /* Shouldn't happen */
211 * We just checked that s->init_num > 0 so this cast should be safe
213 if (((unsigned int)s->init_num) > curr_mtu)
218 if (len > s->max_send_fragment)
219 len = s->max_send_fragment;
222 * XDTLS: this function is too long. split out the CCS part
224 if (type == SSL3_RT_HANDSHAKE) {
225 if (len < DTLS1_HM_HEADER_LENGTH) {
227 * len is so small that we really can't do anything sensible
232 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
234 dtls1_write_message_header(s,
235 (unsigned char *)&s->init_buf->
239 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
243 * might need to update MTU here, but we don't know which
244 * previous packet caused the failure -- so can't really
245 * retransmit anything. continue as if everything is fine and
246 * wait for an alert to handle the retransmit
248 if (retry && BIO_ctrl(SSL_get_wbio(s),
249 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
250 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
251 if (!dtls1_query_mtu(s))
253 /* Have one more go */
263 * bad if this assert fails, only part of the handshake message
264 * got sent. but why would this happen?
266 if (!ossl_assert(len == written))
269 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
271 * should not be done for 'Hello Request's, but in that case
272 * we'll ignore the result anyway
275 (unsigned char *)&s->init_buf->data[s->init_off];
276 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
279 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
281 * reconstruct message header is if it is being sent in
284 *p++ = msg_hdr->type;
285 l2n3(msg_hdr->msg_len, p);
286 s2n(msg_hdr->seq, p);
288 l2n3(msg_hdr->msg_len, p);
289 p -= DTLS1_HM_HEADER_LENGTH;
292 p += DTLS1_HM_HEADER_LENGTH;
293 xlen = written - DTLS1_HM_HEADER_LENGTH;
296 if (!ssl3_finish_mac(s, p, xlen))
300 if (written == s->init_num) {
302 s->msg_callback(1, s->version, type, s->init_buf->data,
303 (size_t)(s->init_off + s->init_num), s,
304 s->msg_callback_arg);
306 s->init_off = 0; /* done writing this message */
311 s->init_off += written;
312 s->init_num -= written;
313 written -= DTLS1_HM_HEADER_LENGTH;
317 * We save the fragment offset for the next fragment so we have it
318 * available in case of an IO retry. We don't know the length of the
319 * next fragment yet so just set that to 0 for now. It will be
320 * updated again later.
322 dtls1_fix_message_header(s, frag_off, 0);
328 int dtls_get_message(SSL *s, int *mt, size_t *len)
330 struct hm_header_st *msg_hdr;
336 msg_hdr = &s->d1->r_msg_hdr;
337 memset(msg_hdr, 0, sizeof(*msg_hdr));
340 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
341 if (errtype == DTLS1_HM_BAD_FRAGMENT
342 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
343 /* bad fragment received */
349 *mt = s->s3->tmp.message_type;
351 p = (unsigned char *)s->init_buf->data;
354 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
355 if (s->msg_callback) {
356 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
357 p, 1, s, s->msg_callback_arg);
360 * This isn't a real handshake message so skip the processing below.
365 msg_len = msg_hdr->msg_len;
367 /* reconstruct message header */
368 *(p++) = msg_hdr->type;
370 s2n(msg_hdr->seq, p);
373 if (s->version != DTLS1_BAD_VER) {
374 p -= DTLS1_HM_HEADER_LENGTH;
375 msg_len += DTLS1_HM_HEADER_LENGTH;
378 if (!ssl3_finish_mac(s, p, msg_len))
381 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
382 p, msg_len, s, s->msg_callback_arg);
384 memset(msg_hdr, 0, sizeof(*msg_hdr));
386 s->d1->handshake_read_seq++;
388 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
394 * dtls1_max_handshake_message_len returns the maximum number of bytes
395 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
396 * may be greater if the maximum certificate list size requires it.
398 static size_t dtls1_max_handshake_message_len(const SSL *s)
400 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
401 if (max_len < s->max_cert_list)
402 return s->max_cert_list;
406 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
408 size_t frag_off, frag_len, msg_len;
410 msg_len = msg_hdr->msg_len;
411 frag_off = msg_hdr->frag_off;
412 frag_len = msg_hdr->frag_len;
414 /* sanity checking */
415 if ((frag_off + frag_len) > msg_len
416 || msg_len > dtls1_max_handshake_message_len(s)) {
417 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
418 return SSL_AD_ILLEGAL_PARAMETER;
421 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
423 * msg_len is limited to 2^24, but is effectively checked against
424 * dtls_max_handshake_message_len(s) above
426 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
427 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
428 return SSL_AD_INTERNAL_ERROR;
431 s->s3->tmp.message_size = msg_len;
432 s->d1->r_msg_hdr.msg_len = msg_len;
433 s->s3->tmp.message_type = msg_hdr->type;
434 s->d1->r_msg_hdr.type = msg_hdr->type;
435 s->d1->r_msg_hdr.seq = msg_hdr->seq;
436 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
438 * They must be playing with us! BTW, failure to enforce upper limit
439 * would open possibility for buffer overrun.
441 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
442 return SSL_AD_ILLEGAL_PARAMETER;
445 return 0; /* no error */
448 static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len)
451 * (0) check whether the desired fragment is available
453 * (1) copy over the fragment to s->init_buf->data[]
454 * (2) update s->init_num
461 item = pqueue_peek(s->d1->buffered_messages);
465 frag = (hm_fragment *)item->data;
467 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
468 /* This is a stale message that has been buffered so clear it */
469 pqueue_pop(s->d1->buffered_messages);
470 dtls1_hm_fragment_free(frag);
475 } while (item == NULL);
477 /* Don't return if reassembly still in progress */
478 if (frag->reassembly != NULL)
481 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
482 size_t frag_len = frag->msg_header.frag_len;
483 pqueue_pop(s->d1->buffered_messages);
485 al = dtls1_preprocess_fragment(s, &frag->msg_header);
487 if (al == 0) { /* no alert */
489 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
490 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
491 frag->msg_header.frag_len);
494 dtls1_hm_fragment_free(frag);
502 ssl3_send_alert(s, SSL3_AL_FATAL, al);
511 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr)
513 hm_fragment *frag = NULL;
515 int i = -1, is_complete;
516 unsigned char seq64be[8];
517 size_t frag_len = msg_hdr->frag_len;
520 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
521 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
525 return DTLS1_HM_FRAGMENT_RETRY;
528 /* Try to find item in queue */
529 memset(seq64be, 0, sizeof(seq64be));
530 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
531 seq64be[7] = (unsigned char)msg_hdr->seq;
532 item = pqueue_find(s->d1->buffered_messages, seq64be);
535 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
538 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
539 frag->msg_header.frag_len = frag->msg_header.msg_len;
540 frag->msg_header.frag_off = 0;
542 frag = (hm_fragment *)item->data;
543 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
551 * If message is already reassembled, this must be a retransmit and can
552 * be dropped. In this case item != NULL and so frag does not need to be
555 if (frag->reassembly == NULL) {
556 unsigned char devnull[256];
559 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
562 sizeof(devnull) ? sizeof(devnull) :
563 frag_len, 0, &readbytes);
566 frag_len -= readbytes;
568 return DTLS1_HM_FRAGMENT_RETRY;
571 /* read the body of the fragment (header has already been read */
572 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
573 frag->fragment + msg_hdr->frag_off,
574 frag_len, 0, &readbytes);
575 if (i <= 0 || readbytes != frag_len)
580 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
581 (long)(msg_hdr->frag_off + frag_len));
583 if (!ossl_assert(msg_hdr->msg_len > 0))
585 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
589 OPENSSL_free(frag->reassembly);
590 frag->reassembly = NULL;
594 item = pitem_new(seq64be, frag);
600 item = pqueue_insert(s->d1->buffered_messages, item);
602 * pqueue_insert fails iff a duplicate item is inserted. However,
603 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
604 * would have returned it and control would never have reached this
607 if (!ossl_assert(item != NULL))
611 return DTLS1_HM_FRAGMENT_RETRY;
615 dtls1_hm_fragment_free(frag);
620 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr)
623 hm_fragment *frag = NULL;
625 unsigned char seq64be[8];
626 size_t frag_len = msg_hdr->frag_len;
629 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
632 /* Try to find item in queue, to prevent duplicate entries */
633 memset(seq64be, 0, sizeof(seq64be));
634 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
635 seq64be[7] = (unsigned char)msg_hdr->seq;
636 item = pqueue_find(s->d1->buffered_messages, seq64be);
639 * If we already have an entry and this one is a fragment, don't discard
640 * it and rather try to reassemble it.
642 if (item != NULL && frag_len != msg_hdr->msg_len)
646 * Discard the message if sequence number was already there, is too far
647 * in the future, already in the queue or if we received a FINISHED
648 * before the SERVER_HELLO, which then must be a stale retransmit.
650 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
651 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
652 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
653 unsigned char devnull[256];
656 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
659 sizeof(devnull) ? sizeof(devnull) :
660 frag_len, 0, &readbytes);
663 frag_len -= readbytes;
666 if (frag_len != msg_hdr->msg_len) {
667 return dtls1_reassemble_fragment(s, msg_hdr);
670 if (frag_len > dtls1_max_handshake_message_len(s))
673 frag = dtls1_hm_fragment_new(frag_len, 0);
677 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
681 * read the body of the fragment (header has already been read
683 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
684 frag->fragment, frag_len, 0,
686 if (i<=0 || readbytes != frag_len)
692 item = pitem_new(seq64be, frag);
696 item = pqueue_insert(s->d1->buffered_messages, item);
698 * pqueue_insert fails iff a duplicate item is inserted. However,
699 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
700 * would have returned it. Then, either |frag_len| !=
701 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
702 * have been processed with |dtls1_reassemble_fragment|, above, or
703 * the record will have been discarded.
705 if (!ossl_assert(item != NULL))
709 return DTLS1_HM_FRAGMENT_RETRY;
713 dtls1_hm_fragment_free(frag);
717 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len)
719 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
720 size_t mlen, frag_off, frag_len;
721 int i, al, recvd_type;
722 struct hm_header_st msg_hdr;
728 /* see if we have the required fragment already */
729 if (dtls1_retrieve_buffered_fragment(s, &frag_len)) {
730 s->init_num = frag_len;
735 /* read handshake message header */
736 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
737 DTLS1_HM_HEADER_LENGTH, 0, &readbytes);
738 if (i <= 0) { /* nbio, or an error */
739 s->rwstate = SSL_READING;
743 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
744 if (wire[0] != SSL3_MT_CCS) {
745 al = SSL_AD_UNEXPECTED_MESSAGE;
746 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
747 SSL_R_BAD_CHANGE_CIPHER_SPEC);
751 memcpy(s->init_buf->data, wire, readbytes);
752 s->init_num = readbytes - 1;
753 s->init_msg = s->init_buf->data + 1;
754 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
755 s->s3->tmp.message_size = readbytes - 1;
756 *len = readbytes - 1;
760 /* Handshake fails if message header is incomplete */
761 if (readbytes != DTLS1_HM_HEADER_LENGTH) {
762 al = SSL_AD_UNEXPECTED_MESSAGE;
763 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
767 /* parse the message fragment header */
768 dtls1_get_message_header(wire, &msg_hdr);
770 mlen = msg_hdr.msg_len;
771 frag_off = msg_hdr.frag_off;
772 frag_len = msg_hdr.frag_len;
775 * We must have at least frag_len bytes left in the record to be read.
776 * Fragments must not span records.
778 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
779 al = SSL_AD_ILLEGAL_PARAMETER;
780 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
785 * if this is a future (or stale) message it gets buffered
786 * (or dropped)--no further processing at this time
787 * While listening, we accept seq 1 (ClientHello with cookie)
788 * although we're still expecting seq 0 (ClientHello)
790 if (msg_hdr.seq != s->d1->handshake_read_seq) {
791 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
795 if (frag_len && frag_len < mlen) {
796 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
801 && s->d1->r_msg_hdr.frag_off == 0
802 && s->statem.hand_state != TLS_ST_OK
803 && wire[0] == SSL3_MT_HELLO_REQUEST) {
805 * The server may always send 'Hello Request' messages -- we are
806 * doing a handshake anyway now, so ignore them if their format is
807 * correct. Does not count for 'Finished' MAC.
809 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
811 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
812 wire, DTLS1_HM_HEADER_LENGTH, s,
813 s->msg_callback_arg);
817 } else { /* Incorrectly formatted Hello request */
819 al = SSL_AD_UNEXPECTED_MESSAGE;
820 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
821 SSL_R_UNEXPECTED_MESSAGE);
826 if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
831 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
833 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
834 &p[frag_off], frag_len, 0, &readbytes);
837 * This shouldn't ever fail due to NBIO because we already checked
838 * that we have enough data in the record
841 s->rwstate = SSL_READING;
850 * XDTLS: an incorrectly formatted fragment should cause the handshake
853 if (readbytes != frag_len) {
854 al = SSL_AD_ILLEGAL_PARAMETER;
855 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
860 * Note that s->init_num is *not* used as current offset in
861 * s->init_buf->data, but as a counter summing up fragments' lengths: as
862 * soon as they sum up to handshake packet length, we assume we have got
865 *len = s->init_num = frag_len;
869 ssl3_send_alert(s, SSL3_AL_FATAL, al);
876 * for these 2 messages, we need to
877 * ssl->enc_read_ctx re-init
878 * ssl->rlayer.read_sequence zero
879 * ssl->s3->read_mac_secret re-init
880 * ssl->session->read_sym_enc assign
881 * ssl->session->read_compression assign
882 * ssl->session->read_hash assign
884 int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
886 if (s->version == DTLS1_BAD_VER) {
887 s->d1->next_handshake_write_seq++;
889 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
890 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
891 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
898 #ifndef OPENSSL_NO_SCTP
899 WORK_STATE dtls_wait_for_dry(SSL *s)
903 /* read app data until dry event */
904 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
909 s->s3->in_read_app_data = 2;
910 s->rwstate = SSL_READING;
911 BIO_clear_retry_flags(SSL_get_rbio(s));
912 BIO_set_retry_read(SSL_get_rbio(s));
915 return WORK_FINISHED_CONTINUE;
919 int dtls1_read_failed(SSL *s, int code)
922 SSLerr(SSL_F_DTLS1_READ_FAILED, ERR_R_INTERNAL_ERROR);
926 if (!dtls1_is_timer_expired(s)) {
928 * not a timeout, none of our business, let higher layers handle
929 * this. in fact it's probably an error
933 /* done, no need to send a retransmit */
936 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
940 return dtls1_handle_timeout(s);
943 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
946 * The index of the retransmission queue actually is the message sequence
947 * number, since the queue only contains messages of a single handshake.
948 * However, the ChangeCipherSpec has no message sequence number and so
949 * using only the sequence will result in the CCS and Finished having the
950 * same index. To prevent this, the sequence number is multiplied by 2.
951 * In case of a CCS 1 is subtracted. This does not only differ CSS and
952 * Finished, it also maintains the order of the index (important for
953 * priority queues) and fits in the unsigned short variable.
955 return seq * 2 - is_ccs;
958 int dtls1_retransmit_buffered_messages(SSL *s)
960 pqueue *sent = s->d1->sent_messages;
966 iter = pqueue_iterator(sent);
968 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
969 frag = (hm_fragment *)item->data;
970 if (dtls1_retransmit_message(s, (unsigned short)
971 dtls1_get_queue_priority
972 (frag->msg_header.seq,
973 frag->msg_header.is_ccs), &found) <= 0)
980 int dtls1_buffer_message(SSL *s, int is_ccs)
984 unsigned char seq64be[8];
987 * this function is called immediately after a message has been
990 if (!ossl_assert(s->init_off == 0))
993 frag = dtls1_hm_fragment_new(s->init_num, 0);
997 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1000 /* For DTLS1_BAD_VER the header length is non-standard */
1001 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1003 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
1004 == (unsigned int)s->init_num))
1007 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1008 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num))
1012 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1013 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1014 frag->msg_header.type = s->d1->w_msg_hdr.type;
1015 frag->msg_header.frag_off = 0;
1016 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1017 frag->msg_header.is_ccs = is_ccs;
1019 /* save current state */
1020 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1021 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1022 frag->msg_header.saved_retransmit_state.compress = s->compress;
1023 frag->msg_header.saved_retransmit_state.session = s->session;
1024 frag->msg_header.saved_retransmit_state.epoch =
1025 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1027 memset(seq64be, 0, sizeof(seq64be));
1030 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1031 frag->msg_header.is_ccs) >> 8);
1034 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1035 frag->msg_header.is_ccs));
1037 item = pitem_new(seq64be, frag);
1039 dtls1_hm_fragment_free(frag);
1043 pqueue_insert(s->d1->sent_messages, item);
1047 int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1050 /* XDTLS: for now assuming that read/writes are blocking */
1053 unsigned long header_length;
1054 unsigned char seq64be[8];
1055 struct dtls1_retransmit_state saved_state;
1057 /* XDTLS: the requested message ought to be found, otherwise error */
1058 memset(seq64be, 0, sizeof(seq64be));
1059 seq64be[6] = (unsigned char)(seq >> 8);
1060 seq64be[7] = (unsigned char)seq;
1062 item = pqueue_find(s->d1->sent_messages, seq64be);
1064 SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE, ERR_R_INTERNAL_ERROR);
1070 frag = (hm_fragment *)item->data;
1072 if (frag->msg_header.is_ccs)
1073 header_length = DTLS1_CCS_HEADER_LENGTH;
1075 header_length = DTLS1_HM_HEADER_LENGTH;
1077 memcpy(s->init_buf->data, frag->fragment,
1078 frag->msg_header.msg_len + header_length);
1079 s->init_num = frag->msg_header.msg_len + header_length;
1081 dtls1_set_message_header_int(s, frag->msg_header.type,
1082 frag->msg_header.msg_len,
1083 frag->msg_header.seq, 0,
1084 frag->msg_header.frag_len);
1086 /* save current state */
1087 saved_state.enc_write_ctx = s->enc_write_ctx;
1088 saved_state.write_hash = s->write_hash;
1089 saved_state.compress = s->compress;
1090 saved_state.session = s->session;
1091 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1093 s->d1->retransmitting = 1;
1095 /* restore state in which the message was originally sent */
1096 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1097 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1098 s->compress = frag->msg_header.saved_retransmit_state.compress;
1099 s->session = frag->msg_header.saved_retransmit_state.session;
1100 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1102 saved_retransmit_state.epoch);
1104 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1105 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1107 /* restore current state */
1108 s->enc_write_ctx = saved_state.enc_write_ctx;
1109 s->write_hash = saved_state.write_hash;
1110 s->compress = saved_state.compress;
1111 s->session = saved_state.session;
1112 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1114 s->d1->retransmitting = 0;
1116 (void)BIO_flush(s->wbio);
1120 void dtls1_set_message_header(SSL *s,
1121 unsigned char mt, size_t len,
1122 size_t frag_off, size_t frag_len)
1124 if (frag_off == 0) {
1125 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1126 s->d1->next_handshake_write_seq++;
1129 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1130 frag_off, frag_len);
1133 /* don't actually do the writing, wait till the MTU has been retrieved */
1135 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1136 size_t len, unsigned short seq_num,
1137 size_t frag_off, size_t frag_len)
1139 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1142 msg_hdr->msg_len = len;
1143 msg_hdr->seq = seq_num;
1144 msg_hdr->frag_off = frag_off;
1145 msg_hdr->frag_len = frag_len;
1149 dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len)
1151 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1153 msg_hdr->frag_off = frag_off;
1154 msg_hdr->frag_len = frag_len;
1157 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1159 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1161 *p++ = msg_hdr->type;
1162 l2n3(msg_hdr->msg_len, p);
1164 s2n(msg_hdr->seq, p);
1165 l2n3(msg_hdr->frag_off, p);
1166 l2n3(msg_hdr->frag_len, p);
1171 void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1173 memset(msg_hdr, 0, sizeof(*msg_hdr));
1174 msg_hdr->type = *(data++);
1175 n2l3(data, msg_hdr->msg_len);
1177 n2s(data, msg_hdr->seq);
1178 n2l3(data, msg_hdr->frag_off);
1179 n2l3(data, msg_hdr->frag_len);
1182 int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype)
1184 unsigned char *header;
1186 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1187 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1188 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1189 s->d1->handshake_write_seq, 0, 0);
1190 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1193 dtls1_set_message_header(s, htype, 0, 0, 0);
1195 * We allocate space at the start for the message header. This gets
1198 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1199 || !WPACKET_start_sub_packet(pkt))
1206 int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
1210 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1211 || !WPACKET_get_length(pkt, &msglen)
1212 || msglen > INT_MAX)
1215 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1216 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1217 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1219 s->init_num = (int)msglen;
1222 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1223 /* Buffer the message to handle re-xmits */
1224 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC