3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
119 #include "ssl_locl.h"
120 #include <openssl/buffer.h>
121 #include <openssl/rand.h>
122 #include <openssl/objects.h>
123 #include <openssl/evp.h>
124 #include <openssl/x509.h>
127 /* XDTLS: figure out the right values */
128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
130 static unsigned int dtls1_min_mtu(void);
131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
133 unsigned long frag_len);
134 static unsigned char *dtls1_write_message_header(SSL *s,
136 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
137 unsigned long len, unsigned short seq_num, unsigned long frag_off,
138 unsigned long frag_len);
139 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
143 dtls1_hm_fragment_new(unsigned long frag_len)
145 hm_fragment *frag = NULL;
146 unsigned char *buf = NULL;
148 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
154 buf = (unsigned char *)OPENSSL_malloc(frag_len);
162 /* zero length fragment gets zero frag->fragment */
163 frag->fragment = buf;
169 dtls1_hm_fragment_free(hm_fragment *frag)
171 if (frag->fragment) OPENSSL_free(frag->fragment);
175 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
176 int dtls1_do_write(SSL *s, int type)
180 unsigned int len, frag_off, mac_size, blocksize;
182 /* AHA! Figure out the MTU, and stick to the right size */
183 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
186 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
188 /* I've seen the kernel return bogus numbers when it doesn't know
189 * (initial write), so just make sure we have a reasonable number */
190 if ( s->d1->mtu < dtls1_min_mtu())
193 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
194 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
201 fprintf(stderr, "using MTU = %d\n", mtu);
203 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
205 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
209 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
212 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
214 ret = BIO_flush(SSL_get_wbio(s));
217 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
220 OPENSSL_assert(mtu > 0); /* should have something reasonable now */
224 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
225 OPENSSL_assert(s->init_num ==
226 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
229 mac_size = EVP_MD_size(s->write_hash);
233 if (s->enc_write_ctx &&
234 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
235 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
242 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
243 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
245 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
247 /* grr.. we could get an error if MTU picked was wrong */
248 ret = BIO_flush(SSL_get_wbio(s));
251 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
252 mac_size - blocksize;
255 if ( s->init_num > curr_mtu)
261 /* XDTLS: this function is too long. split out the CCS part */
262 if ( type == SSL3_RT_HANDSHAKE)
264 if ( s->init_off != 0)
266 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
267 s->init_off -= DTLS1_HM_HEADER_LENGTH;
268 s->init_num += DTLS1_HM_HEADER_LENGTH;
270 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
271 if ( len <= DTLS1_HM_HEADER_LENGTH)
272 len += DTLS1_HM_HEADER_LENGTH;
275 dtls1_fix_message_header(s, frag_off,
276 len - DTLS1_HM_HEADER_LENGTH);
278 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
280 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
283 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
287 /* might need to update MTU here, but we don't know
288 * which previous packet caused the failure -- so can't
289 * really retransmit anything. continue as if everything
290 * is fine and wait for an alert to handle the
293 if ( BIO_ctrl(SSL_get_wbio(s),
294 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
295 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
296 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
303 /* bad if this assert fails, only part of the handshake
304 * message got sent. but why would this happen? */
305 OPENSSL_assert(len == (unsigned int)ret);
307 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
309 /* should not be done for 'Hello Request's, but in that case
310 * we'll ignore the result anyway */
311 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
312 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
315 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
317 /* reconstruct message header is if it
318 * is being sent in single fragment */
319 *p++ = msg_hdr->type;
320 l2n3(msg_hdr->msg_len,p);
321 s2n (msg_hdr->seq,p);
323 l2n3(msg_hdr->msg_len,p);
324 p -= DTLS1_HM_HEADER_LENGTH;
329 p += DTLS1_HM_HEADER_LENGTH;
330 xlen = ret - DTLS1_HM_HEADER_LENGTH;
333 ssl3_finish_mac(s, p, xlen);
336 if (ret == s->init_num)
339 s->msg_callback(1, s->version, type, s->init_buf->data,
340 (size_t)(s->init_off + s->init_num), s,
341 s->msg_callback_arg);
343 s->init_off = 0; /* done writing this message */
350 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
357 /* Obtain handshake message of message type 'mt' (any if mt == -1),
358 * maximum acceptable body length 'max'.
359 * Read an entire handshake message. Handshake messages arrive in
362 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
365 struct hm_header_st *msg_hdr;
367 /* s3->tmp is used to store messages that are unexpected, caused
368 * by the absence of an optional handshake message */
369 if (s->s3->tmp.reuse_message)
371 s->s3->tmp.reuse_message=0;
372 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
374 al=SSL_AD_UNEXPECTED_MESSAGE;
375 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
379 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
380 s->init_num = (int)s->s3->tmp.message_size;
384 msg_hdr = &s->d1->r_msg_hdr;
387 if ( msg_hdr->frag_off == 0)
389 /* s->d1->r_message_header.msg_len = 0; */
390 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
393 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
394 if ( i == DTLS1_HM_BAD_FRAGMENT ||
395 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
397 else if ( i <= 0 && !*ok)
400 /* Note that s->init_sum is used as a counter summing
401 * up fragments' lengths: as soon as they sum up to
402 * handshake packet length, we assume we have got all
403 * the fragments. Overlapping fragments would cause
404 * premature termination, so we don't expect overlaps.
405 * Well, handling overlaps would require something more
406 * drastic. Indeed, as it is now there is no way to
407 * tell if out-of-order fragment from the middle was
408 * the last. '>=' is the best/least we can do to control
409 * the potential damage caused by malformed overlaps. */
410 if ((unsigned int)s->init_num >= msg_hdr->msg_len)
412 unsigned char *p = (unsigned char *)s->init_buf->data;
413 unsigned long msg_len = msg_hdr->msg_len;
415 /* reconstruct message header as if it was
416 * sent in single fragment */
417 *(p++) = msg_hdr->type;
419 s2n (msg_hdr->seq,p);
422 if (s->client_version != DTLS1_BAD_VER)
423 p -= DTLS1_HM_HEADER_LENGTH,
424 msg_len += DTLS1_HM_HEADER_LENGTH;
426 ssl3_finish_mac(s, p, msg_len);
428 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
430 s, s->msg_callback_arg);
432 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
434 s->d1->handshake_read_seq++;
435 /* we just read a handshake message from the other side:
436 * this means that we don't need to retransmit of the
438 * XDTLS: may be able clear out this
439 * buffer a little sooner (i.e if an out-of-order
440 * handshake message/record is received at the record
442 * XDTLS: exception is that the server needs to
443 * know that change cipher spec and finished messages
444 * have been received by the client before clearing this
445 * buffer. this can simply be done by waiting for the
446 * first data segment, but is there a better way? */
447 dtls1_clear_record_buffer(s);
449 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
453 msg_hdr->frag_off = i;
457 ssl3_send_alert(s,SSL3_AL_FATAL,al);
463 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
465 size_t frag_off,frag_len,msg_len;
467 msg_len = msg_hdr->msg_len;
468 frag_off = msg_hdr->frag_off;
469 frag_len = msg_hdr->frag_len;
471 /* sanity checking */
472 if ( (frag_off+frag_len) > msg_len)
474 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
475 return SSL_AD_ILLEGAL_PARAMETER;
478 if ( (frag_off+frag_len) > (unsigned long)max)
480 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
481 return SSL_AD_ILLEGAL_PARAMETER;
484 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
486 /* msg_len is limited to 2^24, but is effectively checked
487 * against max above */
488 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
490 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
491 return SSL_AD_INTERNAL_ERROR;
494 s->s3->tmp.message_size = msg_len;
495 s->d1->r_msg_hdr.msg_len = msg_len;
496 s->s3->tmp.message_type = msg_hdr->type;
497 s->d1->r_msg_hdr.type = msg_hdr->type;
498 s->d1->r_msg_hdr.seq = msg_hdr->seq;
500 else if (msg_len != s->d1->r_msg_hdr.msg_len)
502 /* They must be playing with us! BTW, failure to enforce
503 * upper limit would open possibility for buffer overrun. */
504 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
505 return SSL_AD_ILLEGAL_PARAMETER;
508 return 0; /* no error */
513 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
515 /* (0) check whether the desired fragment is available
517 * (1) copy over the fragment to s->init_buf->data[]
518 * (2) update s->init_num
525 item = pqueue_peek(s->d1->buffered_messages);
529 frag = (hm_fragment *)item->data;
531 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
533 unsigned long frag_len = frag->msg_header.frag_len;
534 pqueue_pop(s->d1->buffered_messages);
536 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
538 if (al==0) /* no alert */
540 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
541 memcpy(&p[frag->msg_header.frag_off],
542 frag->fragment,frag->msg_header.frag_len);
545 dtls1_hm_fragment_free(frag);
554 ssl3_send_alert(s,SSL3_AL_FATAL,al);
565 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
568 hm_fragment *frag = NULL;
571 unsigned long frag_len = msg_hdr->frag_len;
573 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
576 /* Try to find item in queue, to prevent duplicate entries */
577 pq_64bit_init(&seq64);
578 pq_64bit_assign_word(&seq64, msg_hdr->seq);
579 item = pqueue_find(s->d1->buffered_messages, seq64);
580 pq_64bit_free(&seq64);
582 /* Discard the message if sequence number was already there, is
583 * too far in the future, already in the queue or if we received
584 * a FINISHED before the SERVER_HELLO, which then must be a stale
587 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
588 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
589 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
591 unsigned char devnull [256];
595 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
597 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
605 frag = dtls1_hm_fragment_new(frag_len);
609 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
611 /* read the body of the fragment (header has already been read) */
612 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
613 frag->fragment,frag_len,0);
614 if (i<=0 || (unsigned long)i!=frag_len)
617 pq_64bit_init(&seq64);
618 pq_64bit_assign_word(&seq64, msg_hdr->seq);
620 item = pitem_new(seq64, frag);
621 pq_64bit_free(&seq64);
625 pqueue_insert(s->d1->buffered_messages, item);
628 return DTLS1_HM_FRAGMENT_RETRY;
631 if ( frag != NULL) dtls1_hm_fragment_free(frag);
632 if ( item != NULL) OPENSSL_free(item);
639 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
641 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
642 unsigned long l, frag_off, frag_len;
644 struct hm_header_st msg_hdr;
646 /* see if we have the required fragment already */
647 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
649 if (*ok) s->init_num += frag_len;
653 /* read handshake message header */
654 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
655 DTLS1_HM_HEADER_LENGTH, 0);
656 if (i <= 0) /* nbio, or an error */
658 s->rwstate=SSL_READING;
662 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
664 /* parse the message fragment header */
665 dtls1_get_message_header(wire, &msg_hdr);
668 * if this is a future (or stale) message it gets buffered
669 * (or dropped)--no further processing at this time
671 if ( msg_hdr.seq != s->d1->handshake_read_seq)
672 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
675 frag_off = msg_hdr.frag_off;
676 frag_len = msg_hdr.frag_len;
678 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
679 wire[0] == SSL3_MT_HELLO_REQUEST)
681 /* The server may always send 'Hello Request' messages --
682 * we are doing a handshake anyway now, so ignore them
683 * if their format is correct. Does not count for
685 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
688 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
689 wire, DTLS1_HM_HEADER_LENGTH, s,
690 s->msg_callback_arg);
693 return dtls1_get_message_fragment(s, st1, stn,
696 else /* Incorrectly formated Hello request */
698 al=SSL_AD_UNEXPECTED_MESSAGE;
699 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
704 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
707 /* XDTLS: ressurect this when restart is in place */
712 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
714 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
715 &p[frag_off],frag_len,0);
716 /* XDTLS: fix this--message fragments cannot span multiple packets */
719 s->rwstate=SSL_READING;
727 /* XDTLS: an incorrectly formatted fragment should cause the
728 * handshake to fail */
729 OPENSSL_assert(i == (int)frag_len);
733 /* Note that s->init_num is *not* used as current offset in
734 * s->init_buf->data, but as a counter summing up fragments'
735 * lengths: as soon as they sum up to handshake packet
736 * length, we assume we have got all the fragments. */
737 s->init_num += frag_len;
741 ssl3_send_alert(s,SSL3_AL_FATAL,al);
748 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
756 d=(unsigned char *)s->init_buf->data;
757 p= &(d[DTLS1_HM_HEADER_LENGTH]);
759 i=s->method->ssl3_enc->final_finish_mac(s,
760 &(s->s3->finish_dgst1),
761 &(s->s3->finish_dgst2),
762 sender,slen,s->s3->tmp.finish_md);
763 s->s3->tmp.finish_md_len = i;
764 memcpy(p, s->s3->tmp.finish_md, i);
768 #ifdef OPENSSL_SYS_WIN16
769 /* MSVC 1.5 does not clear the top bytes of the word unless
775 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
776 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
779 /* buffer the message to handle re-xmits */
780 dtls1_buffer_message(s, 0);
785 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
786 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
789 /* for these 2 messages, we need to
790 * ssl->enc_read_ctx re-init
791 * ssl->s3->read_sequence zero
792 * ssl->s3->read_mac_secret re-init
793 * ssl->session->read_sym_enc assign
794 * ssl->session->read_compression assign
795 * ssl->session->read_hash assign
797 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
803 p=(unsigned char *)s->init_buf->data;
805 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
806 s->init_num=DTLS1_CCS_HEADER_LENGTH;
808 if (s->client_version == DTLS1_BAD_VER)
810 s->d1->next_handshake_write_seq++;
811 s2n(s->d1->handshake_write_seq,p);
817 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
818 s->d1->handshake_write_seq, 0, 0);
820 /* buffer the message to handle re-xmits */
821 dtls1_buffer_message(s, 1);
826 /* SSL3_ST_CW_CHANGE_B */
827 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
830 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
836 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
838 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
841 p=(unsigned char *)&(buf->data[*l]);
848 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
852 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
855 /* TLSv1 sends a chain with nothing in it, instead of an alert */
857 if (!BUF_MEM_grow_clean(buf,10))
859 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
864 X509_STORE_CTX xs_ctx;
866 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
868 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
872 X509_verify_cert(&xs_ctx);
873 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
875 x = sk_X509_value(xs_ctx.chain, i);
877 if (!dtls1_add_cert_to_buf(buf, &l, x))
879 X509_STORE_CTX_cleanup(&xs_ctx);
883 X509_STORE_CTX_cleanup(&xs_ctx);
885 /* Thawte special :-) */
886 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
888 x=sk_X509_value(s->ctx->extra_certs,i);
889 if (!dtls1_add_cert_to_buf(buf, &l, x))
893 l-= (3 + DTLS1_HM_HEADER_LENGTH);
895 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
898 p=(unsigned char *)&(buf->data[0]);
899 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
901 l+=DTLS1_HM_HEADER_LENGTH;
905 int dtls1_read_failed(SSL *s, int code)
909 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
913 if (!dtls1_is_timer_expired(s))
915 /* not a timeout, none of our business,
916 let higher layers handle this. in fact it's probably an error */
920 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */
922 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
926 #if 0 /* for now, each alert contains only one record number */
927 item = pqueue_peek(state->rcvd_records);
930 /* send an alert immediately for all the missing records */
935 #if 0 /* no more alert sending, just retransmit the last set of messages */
936 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
937 ssl3_send_alert(s,SSL3_AL_WARNING,
938 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
941 return dtls1_handle_timeout(s);
945 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
947 /* The index of the retransmission queue actually is the message sequence number,
948 * since the queue only contains messages of a single handshake. However, the
949 * ChangeCipherSpec has no message sequence number and so using only the sequence
950 * will result in the CCS and Finished having the same index. To prevent this,
951 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
952 * This does not only differ CSS and Finished, it also maintains the order of the
953 * index (important for priority queues) and fits in the unsigned short variable.
955 return seq * 2 - is_ccs;
959 dtls1_retransmit_buffered_messages(SSL *s)
961 pqueue sent = s->d1->sent_messages;
967 iter = pqueue_iterator(sent);
969 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
971 frag = (hm_fragment *)item->data;
972 if ( dtls1_retransmit_message(s,
973 dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
974 0, &found) <= 0 && found)
976 fprintf(stderr, "dtls1_retransmit_message() failed\n");
985 dtls1_buffer_message(SSL *s, int is_ccs)
991 /* this function is called immediately after a message has
993 OPENSSL_assert(s->init_off == 0);
995 frag = dtls1_hm_fragment_new(s->init_num);
997 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1001 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1002 DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
1006 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1007 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1010 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1011 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1012 frag->msg_header.type = s->d1->w_msg_hdr.type;
1013 frag->msg_header.frag_off = 0;
1014 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1015 frag->msg_header.is_ccs = is_ccs;
1017 /* save current state*/
1018 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1019 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1020 frag->msg_header.saved_retransmit_state.compress = s->compress;
1021 frag->msg_header.saved_retransmit_state.session = s->session;
1022 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1024 pq_64bit_init(&seq64);
1026 pq_64bit_assign_word(&seq64,
1027 dtls1_get_queue_priority(frag->msg_header.seq,
1028 frag->msg_header.is_ccs));
1030 item = pitem_new(seq64, frag);
1031 pq_64bit_free(&seq64);
1034 dtls1_hm_fragment_free(frag);
1039 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1040 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1041 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1044 pqueue_insert(s->d1->sent_messages, item);
1049 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1053 /* XDTLS: for now assuming that read/writes are blocking */
1056 unsigned long header_length;
1058 struct dtls1_retransmit_state saved_state;
1059 unsigned char save_write_sequence[8];
1062 OPENSSL_assert(s->init_num == 0);
1063 OPENSSL_assert(s->init_off == 0);
1066 /* XDTLS: the requested message ought to be found, otherwise error */
1067 pq_64bit_init(&seq64);
1068 pq_64bit_assign_word(&seq64, seq);
1070 item = pqueue_find(s->d1->sent_messages, seq64);
1071 pq_64bit_free(&seq64);
1074 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1080 frag = (hm_fragment *)item->data;
1082 if ( frag->msg_header.is_ccs)
1083 header_length = DTLS1_CCS_HEADER_LENGTH;
1085 header_length = DTLS1_HM_HEADER_LENGTH;
1087 memcpy(s->init_buf->data, frag->fragment,
1088 frag->msg_header.msg_len + header_length);
1089 s->init_num = frag->msg_header.msg_len + header_length;
1091 dtls1_set_message_header_int(s, frag->msg_header.type,
1092 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1093 frag->msg_header.frag_len);
1095 /* save current state */
1096 saved_state.enc_write_ctx = s->enc_write_ctx;
1097 saved_state.write_hash = s->write_hash;
1098 saved_state.compress = s->compress;
1099 saved_state.session = s->session;
1100 saved_state.epoch = s->d1->w_epoch;
1101 saved_state.epoch = s->d1->w_epoch;
1103 s->d1->retransmitting = 1;
1105 /* restore state in which the message was originally sent */
1106 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1107 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1108 s->compress = frag->msg_header.saved_retransmit_state.compress;
1109 s->session = frag->msg_header.saved_retransmit_state.session;
1110 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1112 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1114 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1115 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1118 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1119 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1121 /* restore current state */
1122 s->enc_write_ctx = saved_state.enc_write_ctx;
1123 s->write_hash = saved_state.write_hash;
1124 s->compress = saved_state.compress;
1125 s->session = saved_state.session;
1126 s->d1->w_epoch = saved_state.epoch;
1128 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1130 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1131 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1134 s->d1->retransmitting = 0;
1136 (void)BIO_flush(SSL_get_wbio(s));
1140 /* call this function when the buffered messages are no longer needed */
1142 dtls1_clear_record_buffer(SSL *s)
1146 for(item = pqueue_pop(s->d1->sent_messages);
1147 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1149 dtls1_hm_fragment_free((hm_fragment *)item->data);
1156 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1157 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1161 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1162 s->d1->next_handshake_write_seq++;
1165 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1166 frag_off, frag_len);
1168 return p += DTLS1_HM_HEADER_LENGTH;
1172 /* don't actually do the writing, wait till the MTU has been retrieved */
1174 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1175 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1176 unsigned long frag_len)
1178 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1181 msg_hdr->msg_len = len;
1182 msg_hdr->seq = seq_num;
1183 msg_hdr->frag_off = frag_off;
1184 msg_hdr->frag_len = frag_len;
1188 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1189 unsigned long frag_len)
1191 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1193 msg_hdr->frag_off = frag_off;
1194 msg_hdr->frag_len = frag_len;
1197 static unsigned char *
1198 dtls1_write_message_header(SSL *s, unsigned char *p)
1200 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1202 *p++ = msg_hdr->type;
1203 l2n3(msg_hdr->msg_len, p);
1205 s2n(msg_hdr->seq, p);
1206 l2n3(msg_hdr->frag_off, p);
1207 l2n3(msg_hdr->frag_len, p);
1215 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1216 sizeof(g_probable_mtu[0])) - 1]);
1220 dtls1_guess_mtu(unsigned int curr_mtu)
1224 if ( curr_mtu == 0 )
1225 return g_probable_mtu[0] ;
1227 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1228 if ( curr_mtu > g_probable_mtu[i])
1229 return g_probable_mtu[i];
1235 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1237 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1238 msg_hdr->type = *(data++);
1239 n2l3(data, msg_hdr->msg_len);
1241 n2s(data, msg_hdr->seq);
1242 n2l3(data, msg_hdr->frag_off);
1243 n2l3(data, msg_hdr->frag_len);
1247 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1249 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1251 ccs_hdr->type = *(data++);