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 ssl3_finish_mac(s, p, xlen);
300 if (ret == 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 */
313 ret -= 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, unsigned long *len)
330 struct hm_header_st *msg_hdr;
332 unsigned long msg_len;
336 msg_hdr = &s->d1->r_msg_hdr;
337 memset(msg_hdr, 0, sizeof(*msg_hdr));
340 ok = dtls_get_reassembled_message(s, &tmplen);
341 if (tmplen == DTLS1_HM_BAD_FRAGMENT
342 || tmplen == DTLS1_HM_FRAGMENT_RETRY) {
343 /* bad fragment received */
345 } else if (tmplen <= 0 && !ok) {
349 *mt = s->s3->tmp.message_type;
351 p = (unsigned char *)s->init_buf->data;
353 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
354 if (s->msg_callback) {
355 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
356 p, 1, s, s->msg_callback_arg);
359 * This isn't a real handshake message so skip the processing below.
361 *len = (unsigned long)tmplen;
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 ssl3_finish_mac(s, p, msg_len);
380 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
381 p, msg_len, s, s->msg_callback_arg);
383 memset(msg_hdr, 0, sizeof(*msg_hdr));
385 s->d1->handshake_read_seq++;
388 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
394 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
396 size_t frag_off, frag_len, msg_len;
398 msg_len = msg_hdr->msg_len;
399 frag_off = msg_hdr->frag_off;
400 frag_len = msg_hdr->frag_len;
402 /* sanity checking */
403 if ((frag_off + frag_len) > msg_len) {
404 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
405 return SSL_AD_ILLEGAL_PARAMETER;
408 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
410 * msg_len is limited to 2^24, but is effectively checked against max
413 if (!BUF_MEM_grow_clean
414 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
415 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
416 return SSL_AD_INTERNAL_ERROR;
419 s->s3->tmp.message_size = msg_len;
420 s->d1->r_msg_hdr.msg_len = msg_len;
421 s->s3->tmp.message_type = msg_hdr->type;
422 s->d1->r_msg_hdr.type = msg_hdr->type;
423 s->d1->r_msg_hdr.seq = msg_hdr->seq;
424 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
426 * They must be playing with us! BTW, failure to enforce upper limit
427 * would open possibility for buffer overrun.
429 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
430 return SSL_AD_ILLEGAL_PARAMETER;
433 return 0; /* no error */
436 static int dtls1_retrieve_buffered_fragment(SSL *s, int *ok)
439 * (0) check whether the desired fragment is available
441 * (1) copy over the fragment to s->init_buf->data[]
442 * (2) update s->init_num
449 item = pqueue_peek(s->d1->buffered_messages);
453 frag = (hm_fragment *)item->data;
455 /* Don't return if reassembly still in progress */
456 if (frag->reassembly != NULL)
459 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
460 unsigned long frag_len = frag->msg_header.frag_len;
461 pqueue_pop(s->d1->buffered_messages);
463 al = dtls1_preprocess_fragment(s, &frag->msg_header);
465 if (al == 0) { /* no alert */
467 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
468 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
469 frag->msg_header.frag_len);
472 dtls1_hm_fragment_free(frag);
480 ssl3_send_alert(s, SSL3_AL_FATAL, al);
489 * dtls1_max_handshake_message_len returns the maximum number of bytes
490 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
491 * may be greater if the maximum certificate list size requires it.
493 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
495 unsigned long max_len =
496 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
497 if (max_len < (unsigned long)s->max_cert_list)
498 return s->max_cert_list;
503 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
505 hm_fragment *frag = NULL;
507 int i = -1, is_complete;
508 unsigned char seq64be[8];
509 unsigned long frag_len = msg_hdr->frag_len;
511 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
512 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
516 return DTLS1_HM_FRAGMENT_RETRY;
518 /* Try to find item in queue */
519 memset(seq64be, 0, sizeof(seq64be));
520 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
521 seq64be[7] = (unsigned char)msg_hdr->seq;
522 item = pqueue_find(s->d1->buffered_messages, seq64be);
525 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
528 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
529 frag->msg_header.frag_len = frag->msg_header.msg_len;
530 frag->msg_header.frag_off = 0;
532 frag = (hm_fragment *)item->data;
533 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
541 * If message is already reassembled, this must be a retransmit and can
542 * be dropped. In this case item != NULL and so frag does not need to be
545 if (frag->reassembly == NULL) {
546 unsigned char devnull[256];
549 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
552 sizeof(devnull) ? sizeof(devnull) :
558 return DTLS1_HM_FRAGMENT_RETRY;
561 /* read the body of the fragment (header has already been read */
562 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
563 frag->fragment + msg_hdr->frag_off,
565 if ((unsigned long)i != frag_len)
570 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
571 (long)(msg_hdr->frag_off + frag_len));
573 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
577 OPENSSL_free(frag->reassembly);
578 frag->reassembly = NULL;
582 item = pitem_new(seq64be, frag);
588 item = pqueue_insert(s->d1->buffered_messages, item);
590 * pqueue_insert fails iff a duplicate item is inserted. However,
591 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
592 * would have returned it and control would never have reached this
595 OPENSSL_assert(item != NULL);
598 return DTLS1_HM_FRAGMENT_RETRY;
602 dtls1_hm_fragment_free(frag);
608 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
612 hm_fragment *frag = NULL;
614 unsigned char seq64be[8];
615 unsigned long frag_len = msg_hdr->frag_len;
617 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
620 /* Try to find item in queue, to prevent duplicate entries */
621 memset(seq64be, 0, sizeof(seq64be));
622 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
623 seq64be[7] = (unsigned char)msg_hdr->seq;
624 item = pqueue_find(s->d1->buffered_messages, seq64be);
627 * If we already have an entry and this one is a fragment, don't discard
628 * it and rather try to reassemble it.
630 if (item != NULL && frag_len != msg_hdr->msg_len)
634 * Discard the message if sequence number was already there, is too far
635 * in the future, already in the queue or if we received a FINISHED
636 * before the SERVER_HELLO, which then must be a stale retransmit.
638 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
639 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
640 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
642 unsigned char devnull[256];
645 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
648 sizeof(devnull) ? sizeof(devnull) :
655 if (frag_len != msg_hdr->msg_len)
656 return dtls1_reassemble_fragment(s, msg_hdr, ok);
658 if (frag_len > dtls1_max_handshake_message_len(s))
661 frag = dtls1_hm_fragment_new(frag_len, 0);
665 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
669 * read the body of the fragment (header has already been read
671 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
672 frag->fragment, frag_len, 0);
673 if ((unsigned long)i != frag_len)
679 item = pitem_new(seq64be, frag);
683 item = pqueue_insert(s->d1->buffered_messages, item);
685 * pqueue_insert fails iff a duplicate item is inserted. However,
686 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
687 * would have returned it. Then, either |frag_len| !=
688 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
689 * have been processed with |dtls1_reassemble_fragment|, above, or
690 * the record will have been discarded.
692 OPENSSL_assert(item != NULL);
695 return DTLS1_HM_FRAGMENT_RETRY;
699 dtls1_hm_fragment_free(frag);
704 static int dtls_get_reassembled_message(SSL *s, long *len)
706 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
707 unsigned long mlen, frag_off, frag_len;
708 int i, al, recvd_type;
709 struct hm_header_st msg_hdr;
713 /* see if we have the required fragment already */
714 if ((frag_len = dtls1_retrieve_buffered_fragment(s, &ok)) || ok) {
716 s->init_num = frag_len;
721 /* read handshake message header */
722 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
723 DTLS1_HM_HEADER_LENGTH, 0);
724 if (i <= 0) { /* nbio, or an error */
725 s->rwstate = SSL_READING;
729 if(recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
730 if (wire[0] != SSL3_MT_CCS) {
731 al = SSL_AD_UNEXPECTED_MESSAGE;
732 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
733 SSL_R_BAD_CHANGE_CIPHER_SPEC);
737 memcpy(s->init_buf->data, wire, i);
739 s->init_msg = s->init_buf->data + 1;
740 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
741 s->s3->tmp.message_size = i - 1;
746 /* Handshake fails if message header is incomplete */
747 if (i != DTLS1_HM_HEADER_LENGTH) {
748 al = SSL_AD_UNEXPECTED_MESSAGE;
749 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
753 /* parse the message fragment header */
754 dtls1_get_message_header(wire, &msg_hdr);
756 mlen = msg_hdr.msg_len;
757 frag_off = msg_hdr.frag_off;
758 frag_len = msg_hdr.frag_len;
761 * We must have at least frag_len bytes left in the record to be read.
762 * Fragments must not span records.
764 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
765 al = SSL3_AD_ILLEGAL_PARAMETER;
766 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
771 * if this is a future (or stale) message it gets buffered
772 * (or dropped)--no further processing at this time
773 * While listening, we accept seq 1 (ClientHello with cookie)
774 * although we're still expecting seq 0 (ClientHello)
776 if (msg_hdr.seq != s->d1->handshake_read_seq) {
777 *len = dtls1_process_out_of_seq_message(s, &msg_hdr, &ok);
781 if (frag_len && frag_len < mlen) {
782 *len = dtls1_reassemble_fragment(s, &msg_hdr, &ok);
786 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
787 wire[0] == SSL3_MT_HELLO_REQUEST) {
789 * The server may always send 'Hello Request' messages -- we are
790 * doing a handshake anyway now, so ignore them if their format is
791 * correct. Does not count for 'Finished' MAC.
793 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
795 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
796 wire, DTLS1_HM_HEADER_LENGTH, s,
797 s->msg_callback_arg);
801 } else { /* Incorrectly formated Hello request */
803 al = SSL_AD_UNEXPECTED_MESSAGE;
804 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
805 SSL_R_UNEXPECTED_MESSAGE);
810 if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
815 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
817 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
818 &p[frag_off], frag_len, 0);
821 * This shouldn't ever fail due to NBIO because we already checked
822 * that we have enough data in the record
825 s->rwstate = SSL_READING;
833 * XDTLS: an incorrectly formatted fragment should cause the handshake
836 if (i != (int)frag_len) {
837 al = SSL3_AD_ILLEGAL_PARAMETER;
838 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
843 * Note that s->init_num is *not* used as current offset in
844 * s->init_buf->data, but as a counter summing up fragments' lengths: as
845 * soon as they sum up to handshake packet length, we assume we have got
848 *len = s->init_num = frag_len;
852 ssl3_send_alert(s, SSL3_AL_FATAL, al);
859 * for these 2 messages, we need to
860 * ssl->enc_read_ctx re-init
861 * ssl->rlayer.read_sequence zero
862 * ssl->s3->read_mac_secret re-init
863 * ssl->session->read_sym_enc assign
864 * ssl->session->read_compression assign
865 * ssl->session->read_hash assign
867 int dtls_construct_change_cipher_spec(SSL *s)
871 p = (unsigned char *)s->init_buf->data;
873 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
874 s->init_num = DTLS1_CCS_HEADER_LENGTH;
876 if (s->version == DTLS1_BAD_VER) {
877 s->d1->next_handshake_write_seq++;
878 s2n(s->d1->handshake_write_seq, p);
884 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
885 s->d1->handshake_write_seq, 0, 0);
887 /* buffer the message to handle re-xmits */
888 if (!dtls1_buffer_message(s, 1)) {
889 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
896 #ifndef OPENSSL_NO_SCTP
897 WORK_STATE dtls_wait_for_dry(SSL *s)
901 /* read app data until dry event */
902 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
907 s->s3->in_read_app_data = 2;
908 s->rwstate = SSL_READING;
909 BIO_clear_retry_flags(SSL_get_rbio(s));
910 BIO_set_retry_read(SSL_get_rbio(s));
913 return WORK_FINISHED_CONTINUE;
917 int dtls1_read_failed(SSL *s, int code)
920 SSLerr(SSL_F_DTLS1_READ_FAILED, ERR_R_INTERNAL_ERROR);
924 if (!dtls1_is_timer_expired(s)) {
926 * not a timeout, none of our business, let higher layers handle
927 * this. in fact it's probably an error
931 #ifndef OPENSSL_NO_HEARTBEATS
932 /* done, no need to send a retransmit */
933 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
935 /* done, no need to send a retransmit */
939 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
943 return dtls1_handle_timeout(s);
946 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
949 * The index of the retransmission queue actually is the message sequence
950 * number, since the queue only contains messages of a single handshake.
951 * However, the ChangeCipherSpec has no message sequence number and so
952 * using only the sequence will result in the CCS and Finished having the
953 * same index. To prevent this, the sequence number is multiplied by 2.
954 * In case of a CCS 1 is subtracted. This does not only differ CSS and
955 * Finished, it also maintains the order of the index (important for
956 * priority queues) and fits in the unsigned short variable.
958 return seq * 2 - is_ccs;
961 int dtls1_retransmit_buffered_messages(SSL *s)
963 pqueue *sent = s->d1->sent_messages;
969 iter = pqueue_iterator(sent);
971 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
972 frag = (hm_fragment *)item->data;
973 if (dtls1_retransmit_message(s, (unsigned short)
974 dtls1_get_queue_priority
975 (frag->msg_header.seq,
976 frag->msg_header.is_ccs),
984 int dtls1_buffer_message(SSL *s, int is_ccs)
988 unsigned char seq64be[8];
991 * this function is called immediately after a message has been
994 OPENSSL_assert(s->init_off == 0);
996 frag = dtls1_hm_fragment_new(s->init_num, 0);
1000 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1003 /* For DTLS1_BAD_VER the header length is non-standard */
1004 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1005 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1006 == (unsigned int)s->init_num);
1008 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1009 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);
1048 dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1051 /* XDTLS: for now assuming that read/writes are blocking */
1054 unsigned long header_length;
1055 unsigned char seq64be[8];
1056 struct dtls1_retransmit_state saved_state;
1059 OPENSSL_assert(s->init_num == 0);
1060 OPENSSL_assert(s->init_off == 0);
1063 /* XDTLS: the requested message ought to be found, otherwise error */
1064 memset(seq64be, 0, sizeof(seq64be));
1065 seq64be[6] = (unsigned char)(seq >> 8);
1066 seq64be[7] = (unsigned char)seq;
1068 item = pqueue_find(s->d1->sent_messages, seq64be);
1070 SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE, ERR_R_INTERNAL_ERROR);
1076 frag = (hm_fragment *)item->data;
1078 if (frag->msg_header.is_ccs)
1079 header_length = DTLS1_CCS_HEADER_LENGTH;
1081 header_length = DTLS1_HM_HEADER_LENGTH;
1083 memcpy(s->init_buf->data, frag->fragment,
1084 frag->msg_header.msg_len + header_length);
1085 s->init_num = frag->msg_header.msg_len + header_length;
1087 dtls1_set_message_header_int(s, frag->msg_header.type,
1088 frag->msg_header.msg_len,
1089 frag->msg_header.seq, 0,
1090 frag->msg_header.frag_len);
1092 /* save current state */
1093 saved_state.enc_write_ctx = s->enc_write_ctx;
1094 saved_state.write_hash = s->write_hash;
1095 saved_state.compress = s->compress;
1096 saved_state.session = s->session;
1097 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1099 s->d1->retransmitting = 1;
1101 /* restore state in which the message was originally sent */
1102 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1103 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1104 s->compress = frag->msg_header.saved_retransmit_state.compress;
1105 s->session = frag->msg_header.saved_retransmit_state.session;
1106 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1107 frag->msg_header.saved_retransmit_state.epoch);
1109 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1110 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1112 /* restore current state */
1113 s->enc_write_ctx = saved_state.enc_write_ctx;
1114 s->write_hash = saved_state.write_hash;
1115 s->compress = saved_state.compress;
1116 s->session = saved_state.session;
1117 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1119 s->d1->retransmitting = 0;
1121 (void)BIO_flush(SSL_get_wbio(s));
1125 /* call this function when the buffered messages are no longer needed */
1126 void dtls1_clear_record_buffer(SSL *s)
1130 for (item = pqueue_pop(s->d1->sent_messages);
1131 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1132 dtls1_hm_fragment_free((hm_fragment *)item->data);
1137 void dtls1_set_message_header(SSL *s,
1138 unsigned char mt, unsigned long len,
1139 unsigned long frag_off,
1140 unsigned long frag_len)
1142 if (frag_off == 0) {
1143 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1144 s->d1->next_handshake_write_seq++;
1147 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1148 frag_off, frag_len);
1151 /* don't actually do the writing, wait till the MTU has been retrieved */
1153 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1154 unsigned long len, unsigned short seq_num,
1155 unsigned long frag_off, unsigned long frag_len)
1157 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1160 msg_hdr->msg_len = len;
1161 msg_hdr->seq = seq_num;
1162 msg_hdr->frag_off = frag_off;
1163 msg_hdr->frag_len = frag_len;
1167 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1168 unsigned long frag_len)
1170 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1172 msg_hdr->frag_off = frag_off;
1173 msg_hdr->frag_len = frag_len;
1176 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1178 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1180 *p++ = msg_hdr->type;
1181 l2n3(msg_hdr->msg_len, p);
1183 s2n(msg_hdr->seq, p);
1184 l2n3(msg_hdr->frag_off, p);
1185 l2n3(msg_hdr->frag_len, p);
1191 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1193 memset(msg_hdr, 0, sizeof(*msg_hdr));
1194 msg_hdr->type = *(data++);
1195 n2l3(data, msg_hdr->msg_len);
1197 n2s(data, msg_hdr->seq);
1198 n2l3(data, msg_hdr->frag_off);
1199 n2l3(data, msg_hdr->frag_len);