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, unsigned long frag_off,
47 unsigned long frag_len);
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,
52 unsigned long frag_off,
53 unsigned long frag_len);
54 static int dtls_get_reassembled_message(SSL *s, long *len);
56 static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
59 hm_fragment *frag = NULL;
60 unsigned char *buf = NULL;
61 unsigned char *bitmask = NULL;
63 frag = OPENSSL_malloc(sizeof(*frag));
68 buf = OPENSSL_malloc(frag_len);
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) {
88 frag->reassembly = bitmask;
93 void dtls1_hm_fragment_free(hm_fragment *frag)
97 if (frag->msg_header.is_ccs) {
98 EVP_CIPHER_CTX_free(frag->msg_header.
99 saved_retransmit_state.enc_write_ctx);
100 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
102 OPENSSL_free(frag->fragment);
103 OPENSSL_free(frag->reassembly);
108 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
109 * SSL3_RT_CHANGE_CIPHER_SPEC)
111 int dtls1_do_write(SSL *s, int type)
114 unsigned int curr_mtu;
116 unsigned int 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 (int)s->d1->w_msg_hdr.msg_len +
128 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(SSL_get_wbio(s)) + 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(SSL_get_wbio(s));
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 /* Shouldn't ever happen */
223 * XDTLS: this function is too long. split out the CCS part
225 if (type == SSL3_RT_HANDSHAKE) {
226 if (len < DTLS1_HM_HEADER_LENGTH) {
228 * len is so small that we really can't do anything sensible
233 dtls1_fix_message_header(s, frag_off,
234 len - DTLS1_HM_HEADER_LENGTH);
236 dtls1_write_message_header(s,
237 (unsigned char *)&s->init_buf->
241 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
245 * might need to update MTU here, but we don't know which
246 * previous packet caused the failure -- so can't really
247 * retransmit anything. continue as if everything is fine and
248 * wait for an alert to handle the retransmit
250 if (retry && BIO_ctrl(SSL_get_wbio(s),
251 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
252 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
253 if (!dtls1_query_mtu(s))
255 /* Have one more go */
265 * bad if this assert fails, only part of the handshake message
266 * got sent. but why would this happen?
268 OPENSSL_assert(len == (unsigned int)ret);
270 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
272 * should not be done for 'Hello Request's, but in that case
273 * we'll ignore the result anyway
276 (unsigned char *)&s->init_buf->data[s->init_off];
277 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
280 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
282 * reconstruct message header is if it is being sent in
285 *p++ = msg_hdr->type;
286 l2n3(msg_hdr->msg_len, p);
287 s2n(msg_hdr->seq, p);
289 l2n3(msg_hdr->msg_len, p);
290 p -= DTLS1_HM_HEADER_LENGTH;
293 p += DTLS1_HM_HEADER_LENGTH;
294 xlen = ret - DTLS1_HM_HEADER_LENGTH;
297 if (!ssl3_finish_mac(s, p, xlen))
301 if (ret == s->init_num) {
303 s->msg_callback(1, s->version, type, s->init_buf->data,
304 (size_t)(s->init_off + s->init_num), s,
305 s->msg_callback_arg);
307 s->init_off = 0; /* done writing this message */
314 ret -= DTLS1_HM_HEADER_LENGTH;
318 * We save the fragment offset for the next fragment so we have it
319 * available in case of an IO retry. We don't know the length of the
320 * next fragment yet so just set that to 0 for now. It will be
321 * updated again later.
323 dtls1_fix_message_header(s, frag_off, 0);
329 int dtls_get_message(SSL *s, int *mt, unsigned long *len)
331 struct hm_header_st *msg_hdr;
333 unsigned long msg_len;
337 msg_hdr = &s->d1->r_msg_hdr;
338 memset(msg_hdr, 0, sizeof(*msg_hdr));
341 ok = dtls_get_reassembled_message(s, &tmplen);
342 if (tmplen == DTLS1_HM_BAD_FRAGMENT
343 || tmplen == DTLS1_HM_FRAGMENT_RETRY) {
344 /* bad fragment received */
346 } else if (tmplen <= 0 && !ok) {
350 *mt = s->s3->tmp.message_type;
352 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.
362 *len = (unsigned long)tmplen;
366 msg_len = msg_hdr->msg_len;
368 /* reconstruct message header */
369 *(p++) = msg_hdr->type;
371 s2n(msg_hdr->seq, p);
374 if (s->version != DTLS1_BAD_VER) {
375 p -= DTLS1_HM_HEADER_LENGTH;
376 msg_len += DTLS1_HM_HEADER_LENGTH;
379 if (!ssl3_finish_mac(s, p, msg_len))
382 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
383 p, msg_len, s, s->msg_callback_arg);
385 memset(msg_hdr, 0, sizeof(*msg_hdr));
387 s->d1->handshake_read_seq++;
390 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
396 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
398 size_t frag_off, frag_len, msg_len;
400 msg_len = msg_hdr->msg_len;
401 frag_off = msg_hdr->frag_off;
402 frag_len = msg_hdr->frag_len;
404 /* sanity checking */
405 if ((frag_off + frag_len) > msg_len) {
406 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
407 return SSL_AD_ILLEGAL_PARAMETER;
410 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
412 * msg_len is limited to 2^24, but is effectively checked against max
415 if (!BUF_MEM_grow_clean
416 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
417 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
418 return SSL_AD_INTERNAL_ERROR;
421 s->s3->tmp.message_size = msg_len;
422 s->d1->r_msg_hdr.msg_len = msg_len;
423 s->s3->tmp.message_type = msg_hdr->type;
424 s->d1->r_msg_hdr.type = msg_hdr->type;
425 s->d1->r_msg_hdr.seq = msg_hdr->seq;
426 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
428 * They must be playing with us! BTW, failure to enforce upper limit
429 * would open possibility for buffer overrun.
431 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
432 return SSL_AD_ILLEGAL_PARAMETER;
435 return 0; /* no error */
438 static int dtls1_retrieve_buffered_fragment(SSL *s, int *ok)
441 * (0) check whether the desired fragment is available
443 * (1) copy over the fragment to s->init_buf->data[]
444 * (2) update s->init_num
451 item = pqueue_peek(s->d1->buffered_messages);
455 frag = (hm_fragment *)item->data;
457 /* Don't return if reassembly still in progress */
458 if (frag->reassembly != NULL)
461 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
462 unsigned long frag_len = frag->msg_header.frag_len;
463 pqueue_pop(s->d1->buffered_messages);
465 al = dtls1_preprocess_fragment(s, &frag->msg_header);
467 if (al == 0) { /* no alert */
469 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
470 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
471 frag->msg_header.frag_len);
474 dtls1_hm_fragment_free(frag);
482 ssl3_send_alert(s, SSL3_AL_FATAL, al);
491 * dtls1_max_handshake_message_len returns the maximum number of bytes
492 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
493 * may be greater if the maximum certificate list size requires it.
495 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
497 unsigned long max_len =
498 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
499 if (max_len < (unsigned long)s->max_cert_list)
500 return s->max_cert_list;
505 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
507 hm_fragment *frag = NULL;
509 int i = -1, is_complete;
510 unsigned char seq64be[8];
511 unsigned long frag_len = msg_hdr->frag_len;
513 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
514 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
518 return DTLS1_HM_FRAGMENT_RETRY;
520 /* Try to find item in queue */
521 memset(seq64be, 0, sizeof(seq64be));
522 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
523 seq64be[7] = (unsigned char)msg_hdr->seq;
524 item = pqueue_find(s->d1->buffered_messages, seq64be);
527 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
530 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
531 frag->msg_header.frag_len = frag->msg_header.msg_len;
532 frag->msg_header.frag_off = 0;
534 frag = (hm_fragment *)item->data;
535 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
543 * If message is already reassembled, this must be a retransmit and can
544 * be dropped. In this case item != NULL and so frag does not need to be
547 if (frag->reassembly == NULL) {
548 unsigned char devnull[256];
551 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
554 sizeof(devnull) ? sizeof(devnull) :
560 return DTLS1_HM_FRAGMENT_RETRY;
563 /* read the body of the fragment (header has already been read */
564 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
565 frag->fragment + msg_hdr->frag_off,
567 if ((unsigned long)i != frag_len)
572 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
573 (long)(msg_hdr->frag_off + frag_len));
575 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
579 OPENSSL_free(frag->reassembly);
580 frag->reassembly = NULL;
584 item = pitem_new(seq64be, frag);
590 item = pqueue_insert(s->d1->buffered_messages, item);
592 * pqueue_insert fails iff a duplicate item is inserted. However,
593 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
594 * would have returned it and control would never have reached this
597 OPENSSL_assert(item != NULL);
600 return DTLS1_HM_FRAGMENT_RETRY;
604 dtls1_hm_fragment_free(frag);
610 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
614 hm_fragment *frag = NULL;
616 unsigned char seq64be[8];
617 unsigned long frag_len = msg_hdr->frag_len;
619 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
622 /* Try to find item in queue, to prevent duplicate entries */
623 memset(seq64be, 0, sizeof(seq64be));
624 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
625 seq64be[7] = (unsigned char)msg_hdr->seq;
626 item = pqueue_find(s->d1->buffered_messages, seq64be);
629 * If we already have an entry and this one is a fragment, don't discard
630 * it and rather try to reassemble it.
632 if (item != NULL && frag_len != msg_hdr->msg_len)
636 * Discard the message if sequence number was already there, is too far
637 * in the future, already in the queue or if we received a FINISHED
638 * before the SERVER_HELLO, which then must be a stale retransmit.
640 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
641 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
642 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
644 unsigned char devnull[256];
647 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
650 sizeof(devnull) ? sizeof(devnull) :
657 if (frag_len != msg_hdr->msg_len)
658 return dtls1_reassemble_fragment(s, msg_hdr, ok);
660 if (frag_len > dtls1_max_handshake_message_len(s))
663 frag = dtls1_hm_fragment_new(frag_len, 0);
667 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
671 * read the body of the fragment (header has already been read
673 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
674 frag->fragment, frag_len, 0);
675 if ((unsigned long)i != frag_len)
681 item = pitem_new(seq64be, frag);
685 item = pqueue_insert(s->d1->buffered_messages, item);
687 * pqueue_insert fails iff a duplicate item is inserted. However,
688 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
689 * would have returned it. Then, either |frag_len| !=
690 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
691 * have been processed with |dtls1_reassemble_fragment|, above, or
692 * the record will have been discarded.
694 OPENSSL_assert(item != NULL);
697 return DTLS1_HM_FRAGMENT_RETRY;
701 dtls1_hm_fragment_free(frag);
706 static int dtls_get_reassembled_message(SSL *s, long *len)
708 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
709 unsigned long mlen, frag_off, frag_len;
710 int i, al, recvd_type;
711 struct hm_header_st msg_hdr;
715 /* see if we have the required fragment already */
716 if ((frag_len = dtls1_retrieve_buffered_fragment(s, &ok)) || ok) {
718 s->init_num = frag_len;
723 /* read handshake message header */
724 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
725 DTLS1_HM_HEADER_LENGTH, 0);
726 if (i <= 0) { /* nbio, or an error */
727 s->rwstate = SSL_READING;
731 if(recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
732 if (wire[0] != SSL3_MT_CCS) {
733 al = SSL_AD_UNEXPECTED_MESSAGE;
734 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
735 SSL_R_BAD_CHANGE_CIPHER_SPEC);
739 memcpy(s->init_buf->data, wire, i);
741 s->init_msg = s->init_buf->data + 1;
742 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
743 s->s3->tmp.message_size = i - 1;
748 /* Handshake fails if message header is incomplete */
749 if (i != DTLS1_HM_HEADER_LENGTH) {
750 al = SSL_AD_UNEXPECTED_MESSAGE;
751 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
755 /* parse the message fragment header */
756 dtls1_get_message_header(wire, &msg_hdr);
758 mlen = msg_hdr.msg_len;
759 frag_off = msg_hdr.frag_off;
760 frag_len = msg_hdr.frag_len;
763 * We must have at least frag_len bytes left in the record to be read.
764 * Fragments must not span records.
766 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
767 al = SSL3_AD_ILLEGAL_PARAMETER;
768 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
773 * if this is a future (or stale) message it gets buffered
774 * (or dropped)--no further processing at this time
775 * While listening, we accept seq 1 (ClientHello with cookie)
776 * although we're still expecting seq 0 (ClientHello)
778 if (msg_hdr.seq != s->d1->handshake_read_seq) {
779 *len = dtls1_process_out_of_seq_message(s, &msg_hdr, &ok);
783 if (frag_len && frag_len < mlen) {
784 *len = dtls1_reassemble_fragment(s, &msg_hdr, &ok);
788 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
789 wire[0] == SSL3_MT_HELLO_REQUEST) {
791 * The server may always send 'Hello Request' messages -- we are
792 * doing a handshake anyway now, so ignore them if their format is
793 * correct. Does not count for 'Finished' MAC.
795 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
797 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
798 wire, DTLS1_HM_HEADER_LENGTH, s,
799 s->msg_callback_arg);
803 } else { /* Incorrectly formated Hello request */
805 al = SSL_AD_UNEXPECTED_MESSAGE;
806 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
807 SSL_R_UNEXPECTED_MESSAGE);
812 if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
817 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
819 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
820 &p[frag_off], frag_len, 0);
823 * This shouldn't ever fail due to NBIO because we already checked
824 * that we have enough data in the record
827 s->rwstate = SSL_READING;
835 * XDTLS: an incorrectly formatted fragment should cause the handshake
838 if (i != (int)frag_len) {
839 al = SSL3_AD_ILLEGAL_PARAMETER;
840 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
845 * Note that s->init_num is *not* used as current offset in
846 * s->init_buf->data, but as a counter summing up fragments' lengths: as
847 * soon as they sum up to handshake packet length, we assume we have got
850 *len = s->init_num = frag_len;
854 ssl3_send_alert(s, SSL3_AL_FATAL, al);
861 * for these 2 messages, we need to
862 * ssl->enc_read_ctx re-init
863 * ssl->rlayer.read_sequence zero
864 * ssl->s3->read_mac_secret re-init
865 * ssl->session->read_sym_enc assign
866 * ssl->session->read_compression assign
867 * ssl->session->read_hash assign
869 int dtls_construct_change_cipher_spec(SSL *s)
873 p = (unsigned char *)s->init_buf->data;
875 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
876 s->init_num = DTLS1_CCS_HEADER_LENGTH;
878 if (s->version == DTLS1_BAD_VER) {
879 s->d1->next_handshake_write_seq++;
880 s2n(s->d1->handshake_write_seq, p);
886 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
887 s->d1->handshake_write_seq, 0, 0);
889 /* buffer the message to handle re-xmits */
890 if (!dtls1_buffer_message(s, 1)) {
891 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_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 #ifndef OPENSSL_NO_HEARTBEATS
934 /* done, no need to send a retransmit */
935 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
937 /* done, no need to send a retransmit */
941 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
945 return dtls1_handle_timeout(s);
948 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
951 * The index of the retransmission queue actually is the message sequence
952 * number, since the queue only contains messages of a single handshake.
953 * However, the ChangeCipherSpec has no message sequence number and so
954 * using only the sequence will result in the CCS and Finished having the
955 * same index. To prevent this, the sequence number is multiplied by 2.
956 * In case of a CCS 1 is subtracted. This does not only differ CSS and
957 * Finished, it also maintains the order of the index (important for
958 * priority queues) and fits in the unsigned short variable.
960 return seq * 2 - is_ccs;
963 int dtls1_retransmit_buffered_messages(SSL *s)
965 pqueue *sent = s->d1->sent_messages;
971 iter = pqueue_iterator(sent);
973 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
974 frag = (hm_fragment *)item->data;
975 if (dtls1_retransmit_message(s, (unsigned short)
976 dtls1_get_queue_priority
977 (frag->msg_header.seq,
978 frag->msg_header.is_ccs),
986 int dtls1_buffer_message(SSL *s, int is_ccs)
990 unsigned char seq64be[8];
993 * this function is called immediately after a message has been
996 OPENSSL_assert(s->init_off == 0);
998 frag = dtls1_hm_fragment_new(s->init_num, 0);
1002 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1005 /* For DTLS1_BAD_VER the header length is non-standard */
1006 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1007 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1008 == (unsigned int)s->init_num);
1010 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1011 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1014 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1015 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1016 frag->msg_header.type = s->d1->w_msg_hdr.type;
1017 frag->msg_header.frag_off = 0;
1018 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1019 frag->msg_header.is_ccs = is_ccs;
1021 /* save current state */
1022 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1023 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1024 frag->msg_header.saved_retransmit_state.compress = s->compress;
1025 frag->msg_header.saved_retransmit_state.session = s->session;
1026 frag->msg_header.saved_retransmit_state.epoch =
1027 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1029 memset(seq64be, 0, sizeof(seq64be));
1032 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1033 frag->msg_header.is_ccs) >> 8);
1036 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1037 frag->msg_header.is_ccs));
1039 item = pitem_new(seq64be, frag);
1041 dtls1_hm_fragment_free(frag);
1045 pqueue_insert(s->d1->sent_messages, item);
1050 dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1053 /* XDTLS: for now assuming that read/writes are blocking */
1056 unsigned long header_length;
1057 unsigned char seq64be[8];
1058 struct dtls1_retransmit_state saved_state;
1061 OPENSSL_assert(s->init_num == 0);
1062 OPENSSL_assert(s->init_off == 0);
1065 /* XDTLS: the requested message ought to be found, otherwise error */
1066 memset(seq64be, 0, sizeof(seq64be));
1067 seq64be[6] = (unsigned char)(seq >> 8);
1068 seq64be[7] = (unsigned char)seq;
1070 item = pqueue_find(s->d1->sent_messages, seq64be);
1072 SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE, ERR_R_INTERNAL_ERROR);
1078 frag = (hm_fragment *)item->data;
1080 if (frag->msg_header.is_ccs)
1081 header_length = DTLS1_CCS_HEADER_LENGTH;
1083 header_length = DTLS1_HM_HEADER_LENGTH;
1085 memcpy(s->init_buf->data, frag->fragment,
1086 frag->msg_header.msg_len + header_length);
1087 s->init_num = frag->msg_header.msg_len + header_length;
1089 dtls1_set_message_header_int(s, frag->msg_header.type,
1090 frag->msg_header.msg_len,
1091 frag->msg_header.seq, 0,
1092 frag->msg_header.frag_len);
1094 /* save current state */
1095 saved_state.enc_write_ctx = s->enc_write_ctx;
1096 saved_state.write_hash = s->write_hash;
1097 saved_state.compress = s->compress;
1098 saved_state.session = s->session;
1099 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1101 s->d1->retransmitting = 1;
1103 /* restore state in which the message was originally sent */
1104 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1105 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1106 s->compress = frag->msg_header.saved_retransmit_state.compress;
1107 s->session = frag->msg_header.saved_retransmit_state.session;
1108 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1109 frag->msg_header.saved_retransmit_state.epoch);
1111 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1112 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1114 /* restore current state */
1115 s->enc_write_ctx = saved_state.enc_write_ctx;
1116 s->write_hash = saved_state.write_hash;
1117 s->compress = saved_state.compress;
1118 s->session = saved_state.session;
1119 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1121 s->d1->retransmitting = 0;
1123 (void)BIO_flush(SSL_get_wbio(s));
1127 /* call this function when the buffered messages are no longer needed */
1128 void dtls1_clear_record_buffer(SSL *s)
1132 for (item = pqueue_pop(s->d1->sent_messages);
1133 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1134 dtls1_hm_fragment_free((hm_fragment *)item->data);
1139 void dtls1_set_message_header(SSL *s,
1140 unsigned char mt, unsigned long len,
1141 unsigned long frag_off,
1142 unsigned long frag_len)
1144 if (frag_off == 0) {
1145 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1146 s->d1->next_handshake_write_seq++;
1149 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1150 frag_off, frag_len);
1153 /* don't actually do the writing, wait till the MTU has been retrieved */
1155 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1156 unsigned long len, unsigned short seq_num,
1157 unsigned long frag_off, unsigned long frag_len)
1159 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1162 msg_hdr->msg_len = len;
1163 msg_hdr->seq = seq_num;
1164 msg_hdr->frag_off = frag_off;
1165 msg_hdr->frag_len = frag_len;
1169 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1170 unsigned long frag_len)
1172 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1174 msg_hdr->frag_off = frag_off;
1175 msg_hdr->frag_len = frag_len;
1178 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1180 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1182 *p++ = msg_hdr->type;
1183 l2n3(msg_hdr->msg_len, p);
1185 s2n(msg_hdr->seq, p);
1186 l2n3(msg_hdr->frag_off, p);
1187 l2n3(msg_hdr->frag_len, p);
1193 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1195 memset(msg_hdr, 0, sizeof(*msg_hdr));
1196 msg_hdr->type = *(data++);
1197 n2l3(data, msg_hdr->msg_len);
1199 n2s(data, msg_hdr->seq);
1200 n2l3(data, msg_hdr->frag_off);
1201 n2l3(data, msg_hdr->frag_len);