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) { \
35 OPENSSL_assert((msg_len) > 0); \
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 frag = OPENSSL_malloc(sizeof(*frag));
67 buf = OPENSSL_malloc(frag_len);
74 /* zero length fragment gets zero frag->fragment */
77 /* Initialize reassembly bitmask if necessary */
79 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
80 if (bitmask == NULL) {
87 frag->reassembly = bitmask;
92 void dtls1_hm_fragment_free(hm_fragment *frag)
96 if (frag->msg_header.is_ccs) {
97 EVP_CIPHER_CTX_free(frag->msg_header.
98 saved_retransmit_state.enc_write_ctx);
99 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
101 OPENSSL_free(frag->fragment);
102 OPENSSL_free(frag->reassembly);
107 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
108 * SSL3_RT_CHANGE_CIPHER_SPEC)
110 int dtls1_do_write(SSL *s, int type)
116 size_t len, frag_off, mac_size, blocksize, used_len;
118 if (!dtls1_query_mtu(s))
121 if (s->d1->mtu < dtls1_min_mtu(s))
122 /* should have something reasonable now */
125 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
126 OPENSSL_assert(s->init_num ==
127 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
131 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_write_ctx)) &
132 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
135 mac_size = EVP_MD_CTX_size(s->write_hash);
139 if (s->enc_write_ctx &&
140 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
141 blocksize = 2 * EVP_CIPHER_CTX_block_size(s->enc_write_ctx);
146 s->rwstate = SSL_NOTHING;
148 /* s->init_num shouldn't ever be < 0...but just in case */
149 while (s->init_num > 0) {
150 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
151 /* We must be writing a fragment other than the first one */
154 /* This is the first attempt at writing out this fragment */
156 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
158 * Each fragment that was already sent must at least have
159 * contained the message header plus one other byte.
160 * Therefore |init_off| must have progressed by at least
161 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
168 * Adjust |init_off| and |init_num| to allow room for a new
169 * message header for this fragment.
171 s->init_off -= DTLS1_HM_HEADER_LENGTH;
172 s->init_num += DTLS1_HM_HEADER_LENGTH;
175 * We must have been called again after a retry so use the
176 * fragment offset from our last attempt. We do not need
177 * to adjust |init_off| and |init_num| as above, because
178 * that should already have been done before the retry.
180 frag_off = s->d1->w_msg_hdr.frag_off;
184 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
185 + mac_size + blocksize;
186 if (s->d1->mtu > used_len)
187 curr_mtu = s->d1->mtu - used_len;
191 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
193 * grr.. we could get an error if MTU picked was wrong
195 ret = BIO_flush(s->wbio);
197 s->rwstate = SSL_WRITING;
200 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
201 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
202 curr_mtu = s->d1->mtu - used_len;
204 /* Shouldn't happen */
210 * We just checked that s->init_num > 0 so this cast should be safe
212 if (((unsigned int)s->init_num) > curr_mtu)
218 * XDTLS: this function is too long. split out the CCS part
220 if (type == SSL3_RT_HANDSHAKE) {
221 if (len < DTLS1_HM_HEADER_LENGTH) {
223 * len is so small that we really can't do anything sensible
228 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
230 dtls1_write_message_header(s,
231 (unsigned char *)&s->init_buf->
235 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
239 * might need to update MTU here, but we don't know which
240 * previous packet caused the failure -- so can't really
241 * retransmit anything. continue as if everything is fine and
242 * wait for an alert to handle the retransmit
244 if (retry && BIO_ctrl(SSL_get_wbio(s),
245 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
246 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
247 if (!dtls1_query_mtu(s))
249 /* Have one more go */
259 * bad if this assert fails, only part of the handshake message
260 * got sent. but why would this happen?
262 OPENSSL_assert(len == written);
264 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
266 * should not be done for 'Hello Request's, but in that case
267 * we'll ignore the result anyway
270 (unsigned char *)&s->init_buf->data[s->init_off];
271 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
274 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
276 * reconstruct message header is if it is being sent in
279 *p++ = msg_hdr->type;
280 l2n3(msg_hdr->msg_len, p);
281 s2n(msg_hdr->seq, p);
283 l2n3(msg_hdr->msg_len, p);
284 p -= DTLS1_HM_HEADER_LENGTH;
287 p += DTLS1_HM_HEADER_LENGTH;
288 xlen = written - DTLS1_HM_HEADER_LENGTH;
291 if (!ssl3_finish_mac(s, p, xlen))
295 if (written == s->init_num) {
297 s->msg_callback(1, s->version, type, s->init_buf->data,
298 (size_t)(s->init_off + s->init_num), s,
299 s->msg_callback_arg);
301 s->init_off = 0; /* done writing this message */
306 s->init_off += written;
307 s->init_num -= written;
308 written -= DTLS1_HM_HEADER_LENGTH;
312 * We save the fragment offset for the next fragment so we have it
313 * available in case of an IO retry. We don't know the length of the
314 * next fragment yet so just set that to 0 for now. It will be
315 * updated again later.
317 dtls1_fix_message_header(s, frag_off, 0);
323 int dtls_get_message(SSL *s, int *mt, size_t *len)
325 struct hm_header_st *msg_hdr;
331 msg_hdr = &s->d1->r_msg_hdr;
332 memset(msg_hdr, 0, sizeof(*msg_hdr));
335 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
336 if (errtype == DTLS1_HM_BAD_FRAGMENT
337 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
338 /* bad fragment received */
344 *mt = s->s3->tmp.message_type;
346 p = (unsigned char *)s->init_buf->data;
349 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
350 if (s->msg_callback) {
351 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
352 p, 1, s, s->msg_callback_arg);
355 * This isn't a real handshake message so skip the processing below.
360 msg_len = msg_hdr->msg_len;
362 /* reconstruct message header */
363 *(p++) = msg_hdr->type;
365 s2n(msg_hdr->seq, p);
368 if (s->version != DTLS1_BAD_VER) {
369 p -= DTLS1_HM_HEADER_LENGTH;
370 msg_len += DTLS1_HM_HEADER_LENGTH;
373 if (!ssl3_finish_mac(s, p, msg_len))
376 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
377 p, msg_len, s, s->msg_callback_arg);
379 memset(msg_hdr, 0, sizeof(*msg_hdr));
381 s->d1->handshake_read_seq++;
383 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
389 * dtls1_max_handshake_message_len returns the maximum number of bytes
390 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
391 * may be greater if the maximum certificate list size requires it.
393 static size_t dtls1_max_handshake_message_len(const SSL *s)
395 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
396 if (max_len < s->max_cert_list)
397 return s->max_cert_list;
401 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
403 size_t frag_off, frag_len, msg_len;
405 msg_len = msg_hdr->msg_len;
406 frag_off = msg_hdr->frag_off;
407 frag_len = msg_hdr->frag_len;
409 /* sanity checking */
410 if ((frag_off + frag_len) > msg_len
411 || msg_len > dtls1_max_handshake_message_len(s)) {
412 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
413 return SSL_AD_ILLEGAL_PARAMETER;
416 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
418 * msg_len is limited to 2^24, but is effectively checked against
419 * dtls_max_handshake_message_len(s) above
421 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
422 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
423 return SSL_AD_INTERNAL_ERROR;
426 s->s3->tmp.message_size = msg_len;
427 s->d1->r_msg_hdr.msg_len = msg_len;
428 s->s3->tmp.message_type = msg_hdr->type;
429 s->d1->r_msg_hdr.type = msg_hdr->type;
430 s->d1->r_msg_hdr.seq = msg_hdr->seq;
431 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
433 * They must be playing with us! BTW, failure to enforce upper limit
434 * would open possibility for buffer overrun.
436 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
437 return SSL_AD_ILLEGAL_PARAMETER;
440 return 0; /* no error */
443 static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len)
446 * (0) check whether the desired fragment is available
448 * (1) copy over the fragment to s->init_buf->data[]
449 * (2) update s->init_num
456 item = pqueue_peek(s->d1->buffered_messages);
460 frag = (hm_fragment *)item->data;
462 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
463 /* This is a stale message that has been buffered so clear it */
464 pqueue_pop(s->d1->buffered_messages);
465 dtls1_hm_fragment_free(frag);
470 } while (item == NULL);
472 /* Don't return if reassembly still in progress */
473 if (frag->reassembly != NULL)
476 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
477 size_t frag_len = frag->msg_header.frag_len;
478 pqueue_pop(s->d1->buffered_messages);
480 al = dtls1_preprocess_fragment(s, &frag->msg_header);
482 if (al == 0) { /* no alert */
484 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
485 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
486 frag->msg_header.frag_len);
489 dtls1_hm_fragment_free(frag);
497 ssl3_send_alert(s, SSL3_AL_FATAL, al);
506 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr)
508 hm_fragment *frag = NULL;
510 int i = -1, is_complete;
511 unsigned char seq64be[8];
512 size_t frag_len = msg_hdr->frag_len;
515 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
516 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
520 return DTLS1_HM_FRAGMENT_RETRY;
523 /* Try to find item in queue */
524 memset(seq64be, 0, sizeof(seq64be));
525 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
526 seq64be[7] = (unsigned char)msg_hdr->seq;
527 item = pqueue_find(s->d1->buffered_messages, seq64be);
530 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
533 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
534 frag->msg_header.frag_len = frag->msg_header.msg_len;
535 frag->msg_header.frag_off = 0;
537 frag = (hm_fragment *)item->data;
538 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
546 * If message is already reassembled, this must be a retransmit and can
547 * be dropped. In this case item != NULL and so frag does not need to be
550 if (frag->reassembly == NULL) {
551 unsigned char devnull[256];
554 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
557 sizeof(devnull) ? sizeof(devnull) :
563 return DTLS1_HM_FRAGMENT_RETRY;
566 /* read the body of the fragment (header has already been read */
567 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
568 frag->fragment + msg_hdr->frag_off,
570 if (i <= 0 || read != frag_len)
575 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
576 (long)(msg_hdr->frag_off + frag_len));
578 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
582 OPENSSL_free(frag->reassembly);
583 frag->reassembly = NULL;
587 item = pitem_new(seq64be, frag);
593 item = pqueue_insert(s->d1->buffered_messages, item);
595 * pqueue_insert fails iff a duplicate item is inserted. However,
596 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
597 * would have returned it and control would never have reached this
600 OPENSSL_assert(item != NULL);
603 return DTLS1_HM_FRAGMENT_RETRY;
607 dtls1_hm_fragment_free(frag);
612 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr)
615 hm_fragment *frag = NULL;
617 unsigned char seq64be[8];
618 size_t frag_len = msg_hdr->frag_len;
621 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
624 /* Try to find item in queue, to prevent duplicate entries */
625 memset(seq64be, 0, sizeof(seq64be));
626 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
627 seq64be[7] = (unsigned char)msg_hdr->seq;
628 item = pqueue_find(s->d1->buffered_messages, seq64be);
631 * If we already have an entry and this one is a fragment, don't discard
632 * it and rather try to reassemble it.
634 if (item != NULL && frag_len != msg_hdr->msg_len)
638 * Discard the message if sequence number was already there, is too far
639 * in the future, already in the queue or if we received a FINISHED
640 * before the SERVER_HELLO, which then must be a stale retransmit.
642 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
643 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
644 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
645 unsigned char devnull[256];
648 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
651 sizeof(devnull) ? sizeof(devnull) :
658 if (frag_len != msg_hdr->msg_len) {
659 return dtls1_reassemble_fragment(s, msg_hdr);;
662 if (frag_len > dtls1_max_handshake_message_len(s))
665 frag = dtls1_hm_fragment_new(frag_len, 0);
669 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
673 * read the body of the fragment (header has already been read
675 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
676 frag->fragment, frag_len, 0, &read);
677 if (i<=0 || read != frag_len)
683 item = pitem_new(seq64be, frag);
687 item = pqueue_insert(s->d1->buffered_messages, item);
689 * pqueue_insert fails iff a duplicate item is inserted. However,
690 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
691 * would have returned it. Then, either |frag_len| !=
692 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
693 * have been processed with |dtls1_reassemble_fragment|, above, or
694 * the record will have been discarded.
696 OPENSSL_assert(item != NULL);
699 return DTLS1_HM_FRAGMENT_RETRY;
703 dtls1_hm_fragment_free(frag);
707 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len)
709 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
710 size_t mlen, frag_off, frag_len;
711 int i, al, recvd_type;
712 struct hm_header_st msg_hdr;
718 /* see if we have the required fragment already */
719 if (dtls1_retrieve_buffered_fragment(s, &frag_len)) {
720 s->init_num = frag_len;
725 /* read handshake message header */
726 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
727 DTLS1_HM_HEADER_LENGTH, 0, &read);
728 if (i <= 0) { /* nbio, or an error */
729 s->rwstate = SSL_READING;
733 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
734 if (wire[0] != SSL3_MT_CCS) {
735 al = SSL_AD_UNEXPECTED_MESSAGE;
736 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
737 SSL_R_BAD_CHANGE_CIPHER_SPEC);
741 memcpy(s->init_buf->data, wire, read);
742 s->init_num = read - 1;
743 s->init_msg = s->init_buf->data + 1;
744 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
745 s->s3->tmp.message_size = read - 1;
750 /* Handshake fails if message header is incomplete */
751 if (read != DTLS1_HM_HEADER_LENGTH) {
752 al = SSL_AD_UNEXPECTED_MESSAGE;
753 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
757 /* parse the message fragment header */
758 dtls1_get_message_header(wire, &msg_hdr);
760 mlen = msg_hdr.msg_len;
761 frag_off = msg_hdr.frag_off;
762 frag_len = msg_hdr.frag_len;
765 * We must have at least frag_len bytes left in the record to be read.
766 * Fragments must not span records.
768 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
769 al = SSL3_AD_ILLEGAL_PARAMETER;
770 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
775 * if this is a future (or stale) message it gets buffered
776 * (or dropped)--no further processing at this time
777 * While listening, we accept seq 1 (ClientHello with cookie)
778 * although we're still expecting seq 0 (ClientHello)
780 if (msg_hdr.seq != s->d1->handshake_read_seq) {
781 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
785 if (frag_len && frag_len < mlen) {
786 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
790 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
791 wire[0] == SSL3_MT_HELLO_REQUEST) {
793 * The server may always send 'Hello Request' messages -- we are
794 * doing a handshake anyway now, so ignore them if their format is
795 * correct. Does not count for 'Finished' MAC.
797 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
799 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
800 wire, DTLS1_HM_HEADER_LENGTH, s,
801 s->msg_callback_arg);
805 } else { /* Incorrectly formatted Hello request */
807 al = SSL_AD_UNEXPECTED_MESSAGE;
808 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
809 SSL_R_UNEXPECTED_MESSAGE);
814 if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
819 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
821 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
822 &p[frag_off], frag_len, 0, &read);
825 * This shouldn't ever fail due to NBIO because we already checked
826 * that we have enough data in the record
829 s->rwstate = SSL_READING;
838 * XDTLS: an incorrectly formatted fragment should cause the handshake
841 if (read != frag_len) {
842 al = SSL3_AD_ILLEGAL_PARAMETER;
843 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
848 * Note that s->init_num is *not* used as current offset in
849 * s->init_buf->data, but as a counter summing up fragments' lengths: as
850 * soon as they sum up to handshake packet length, we assume we have got
853 *len = s->init_num = frag_len;
857 ssl3_send_alert(s, SSL3_AL_FATAL, al);
864 * for these 2 messages, we need to
865 * ssl->enc_read_ctx re-init
866 * ssl->rlayer.read_sequence zero
867 * ssl->s3->read_mac_secret re-init
868 * ssl->session->read_sym_enc assign
869 * ssl->session->read_compression assign
870 * ssl->session->read_hash assign
872 int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
874 if (s->version == DTLS1_BAD_VER) {
875 s->d1->next_handshake_write_seq++;
877 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
878 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
879 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
886 #ifndef OPENSSL_NO_SCTP
887 WORK_STATE dtls_wait_for_dry(SSL *s)
891 /* read app data until dry event */
892 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
897 s->s3->in_read_app_data = 2;
898 s->rwstate = SSL_READING;
899 BIO_clear_retry_flags(SSL_get_rbio(s));
900 BIO_set_retry_read(SSL_get_rbio(s));
903 return WORK_FINISHED_CONTINUE;
907 int dtls1_read_failed(SSL *s, int code)
910 SSLerr(SSL_F_DTLS1_READ_FAILED, ERR_R_INTERNAL_ERROR);
914 if (!dtls1_is_timer_expired(s)) {
916 * not a timeout, none of our business, let higher layers handle
917 * this. in fact it's probably an error
921 #ifndef OPENSSL_NO_HEARTBEATS
922 /* done, no need to send a retransmit */
923 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
925 /* done, no need to send a retransmit */
929 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
933 return dtls1_handle_timeout(s);
936 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
939 * The index of the retransmission queue actually is the message sequence
940 * number, since the queue only contains messages of a single handshake.
941 * However, the ChangeCipherSpec has no message sequence number and so
942 * using only the sequence will result in the CCS and Finished having the
943 * same index. To prevent this, the sequence number is multiplied by 2.
944 * In case of a CCS 1 is subtracted. This does not only differ CSS and
945 * Finished, it also maintains the order of the index (important for
946 * priority queues) and fits in the unsigned short variable.
948 return seq * 2 - is_ccs;
951 int dtls1_retransmit_buffered_messages(SSL *s)
953 pqueue *sent = s->d1->sent_messages;
959 iter = pqueue_iterator(sent);
961 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
962 frag = (hm_fragment *)item->data;
963 if (dtls1_retransmit_message(s, (unsigned short)
964 dtls1_get_queue_priority
965 (frag->msg_header.seq,
966 frag->msg_header.is_ccs), &found) <= 0)
973 int dtls1_buffer_message(SSL *s, int is_ccs)
977 unsigned char seq64be[8];
980 * this function is called immediately after a message has been
983 OPENSSL_assert(s->init_off == 0);
985 frag = dtls1_hm_fragment_new(s->init_num, 0);
989 memcpy(frag->fragment, s->init_buf->data, s->init_num);
992 /* For DTLS1_BAD_VER the header length is non-standard */
993 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
995 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
996 == (unsigned int)s->init_num);
998 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
999 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1002 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1003 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1004 frag->msg_header.type = s->d1->w_msg_hdr.type;
1005 frag->msg_header.frag_off = 0;
1006 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1007 frag->msg_header.is_ccs = is_ccs;
1009 /* save current state */
1010 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1011 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1012 frag->msg_header.saved_retransmit_state.compress = s->compress;
1013 frag->msg_header.saved_retransmit_state.session = s->session;
1014 frag->msg_header.saved_retransmit_state.epoch =
1015 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1017 memset(seq64be, 0, sizeof(seq64be));
1020 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1021 frag->msg_header.is_ccs) >> 8);
1024 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1025 frag->msg_header.is_ccs));
1027 item = pitem_new(seq64be, frag);
1029 dtls1_hm_fragment_free(frag);
1033 pqueue_insert(s->d1->sent_messages, item);
1037 int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1040 /* XDTLS: for now assuming that read/writes are blocking */
1043 unsigned long header_length;
1044 unsigned char seq64be[8];
1045 struct dtls1_retransmit_state saved_state;
1048 OPENSSL_assert(s->init_num == 0);
1049 OPENSSL_assert(s->init_off == 0);
1052 /* XDTLS: the requested message ought to be found, otherwise error */
1053 memset(seq64be, 0, sizeof(seq64be));
1054 seq64be[6] = (unsigned char)(seq >> 8);
1055 seq64be[7] = (unsigned char)seq;
1057 item = pqueue_find(s->d1->sent_messages, seq64be);
1059 SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE, ERR_R_INTERNAL_ERROR);
1065 frag = (hm_fragment *)item->data;
1067 if (frag->msg_header.is_ccs)
1068 header_length = DTLS1_CCS_HEADER_LENGTH;
1070 header_length = DTLS1_HM_HEADER_LENGTH;
1072 memcpy(s->init_buf->data, frag->fragment,
1073 frag->msg_header.msg_len + header_length);
1074 s->init_num = frag->msg_header.msg_len + header_length;
1076 dtls1_set_message_header_int(s, frag->msg_header.type,
1077 frag->msg_header.msg_len,
1078 frag->msg_header.seq, 0,
1079 frag->msg_header.frag_len);
1081 /* save current state */
1082 saved_state.enc_write_ctx = s->enc_write_ctx;
1083 saved_state.write_hash = s->write_hash;
1084 saved_state.compress = s->compress;
1085 saved_state.session = s->session;
1086 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1088 s->d1->retransmitting = 1;
1090 /* restore state in which the message was originally sent */
1091 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1092 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1093 s->compress = frag->msg_header.saved_retransmit_state.compress;
1094 s->session = frag->msg_header.saved_retransmit_state.session;
1095 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1097 saved_retransmit_state.epoch);
1099 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1100 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1102 /* restore current state */
1103 s->enc_write_ctx = saved_state.enc_write_ctx;
1104 s->write_hash = saved_state.write_hash;
1105 s->compress = saved_state.compress;
1106 s->session = saved_state.session;
1107 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1109 s->d1->retransmitting = 0;
1111 (void)BIO_flush(s->wbio);
1115 void dtls1_set_message_header(SSL *s,
1116 unsigned char mt, size_t len,
1117 size_t frag_off, size_t frag_len)
1119 if (frag_off == 0) {
1120 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1121 s->d1->next_handshake_write_seq++;
1124 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1125 frag_off, frag_len);
1128 /* don't actually do the writing, wait till the MTU has been retrieved */
1130 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1131 size_t len, unsigned short seq_num,
1132 size_t frag_off, size_t frag_len)
1134 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1137 msg_hdr->msg_len = len;
1138 msg_hdr->seq = seq_num;
1139 msg_hdr->frag_off = frag_off;
1140 msg_hdr->frag_len = frag_len;
1144 dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len)
1146 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1148 msg_hdr->frag_off = frag_off;
1149 msg_hdr->frag_len = frag_len;
1152 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1154 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1156 *p++ = msg_hdr->type;
1157 l2n3(msg_hdr->msg_len, p);
1159 s2n(msg_hdr->seq, p);
1160 l2n3(msg_hdr->frag_off, p);
1161 l2n3(msg_hdr->frag_len, p);
1166 void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1168 memset(msg_hdr, 0, sizeof(*msg_hdr));
1169 msg_hdr->type = *(data++);
1170 n2l3(data, msg_hdr->msg_len);
1172 n2s(data, msg_hdr->seq);
1173 n2l3(data, msg_hdr->frag_off);
1174 n2l3(data, msg_hdr->frag_len);
1177 int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype)
1179 unsigned char *header;
1181 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1182 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1183 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1184 s->d1->handshake_write_seq, 0, 0);
1185 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1188 dtls1_set_message_header(s, htype, 0, 0, 0);
1190 * We allocate space at the start for the message header. This gets
1193 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1194 || !WPACKET_start_sub_packet(pkt))
1201 int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
1205 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1206 || !WPACKET_get_length(pkt, &msglen)
1207 || msglen > INT_MAX)
1210 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1211 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1212 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1214 s->init_num = (int)msglen;
1217 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1218 /* Buffer the message to handle re-xmits */
1219 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC