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>
126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129 if ((end) - (start) <= 8) { \
131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
141 OPENSSL_assert((msg_len) > 0); \
143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
155 static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156 static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
158 /* XDTLS: figure out the right values */
159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
163 unsigned long frag_len);
164 static unsigned char *dtls1_write_message_header(SSL *s,
166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
167 unsigned long len, unsigned short seq_num, unsigned long frag_off,
168 unsigned long frag_len);
169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
173 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
175 hm_fragment *frag = NULL;
176 unsigned char *buf = NULL;
177 unsigned char *bitmask = NULL;
179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
185 buf = (unsigned char *)OPENSSL_malloc(frag_len);
193 /* zero length fragment gets zero frag->fragment */
194 frag->fragment = buf;
196 /* Initialize reassembly bitmask if necessary */
199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
202 if (buf != NULL) OPENSSL_free(buf);
206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
209 frag->reassembly = bitmask;
215 dtls1_hm_fragment_free(hm_fragment *frag)
217 if (frag->fragment) OPENSSL_free(frag->fragment);
218 if (frag->reassembly) OPENSSL_free(frag->reassembly);
222 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
223 int dtls1_do_write(SSL *s, int type)
227 unsigned int len, frag_off, mac_size, blocksize;
229 /* AHA! Figure out the MTU, and stick to the right size */
230 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
233 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
235 /* I've seen the kernel return bogus numbers when it doesn't know
236 * (initial write), so just make sure we have a reasonable number */
237 if (s->d1->mtu < dtls1_min_mtu())
240 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
241 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
248 fprintf(stderr, "using MTU = %d\n", mtu);
250 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
252 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
256 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
259 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
261 ret = BIO_flush(SSL_get_wbio(s));
264 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
268 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
270 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
271 OPENSSL_assert(s->init_num ==
272 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
275 mac_size = EVP_MD_CTX_size(s->write_hash);
279 if (s->enc_write_ctx &&
280 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
281 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
288 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
289 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
291 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
293 /* grr.. we could get an error if MTU picked was wrong */
294 ret = BIO_flush(SSL_get_wbio(s));
297 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
298 mac_size - blocksize;
301 if ( s->init_num > curr_mtu)
307 /* XDTLS: this function is too long. split out the CCS part */
308 if ( type == SSL3_RT_HANDSHAKE)
310 if ( s->init_off != 0)
312 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
313 s->init_off -= DTLS1_HM_HEADER_LENGTH;
314 s->init_num += DTLS1_HM_HEADER_LENGTH;
316 if ( s->init_num > curr_mtu)
322 dtls1_fix_message_header(s, frag_off,
323 len - DTLS1_HM_HEADER_LENGTH);
325 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
327 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
330 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
334 /* might need to update MTU here, but we don't know
335 * which previous packet caused the failure -- so can't
336 * really retransmit anything. continue as if everything
337 * is fine and wait for an alert to handle the
340 if ( BIO_ctrl(SSL_get_wbio(s),
341 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
342 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
343 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
350 /* bad if this assert fails, only part of the handshake
351 * message got sent. but why would this happen? */
352 OPENSSL_assert(len == (unsigned int)ret);
354 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
356 /* should not be done for 'Hello Request's, but in that case
357 * we'll ignore the result anyway */
358 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
359 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
362 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
364 /* reconstruct message header is if it
365 * is being sent in single fragment */
366 *p++ = msg_hdr->type;
367 l2n3(msg_hdr->msg_len,p);
368 s2n (msg_hdr->seq,p);
370 l2n3(msg_hdr->msg_len,p);
371 p -= DTLS1_HM_HEADER_LENGTH;
376 p += DTLS1_HM_HEADER_LENGTH;
377 xlen = ret - DTLS1_HM_HEADER_LENGTH;
380 ssl3_finish_mac(s, p, xlen);
383 if (ret == s->init_num)
386 s->msg_callback(1, s->version, type, s->init_buf->data,
387 (size_t)(s->init_off + s->init_num), s,
388 s->msg_callback_arg);
390 s->init_off = 0; /* done writing this message */
397 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
404 /* Obtain handshake message of message type 'mt' (any if mt == -1),
405 * maximum acceptable body length 'max'.
406 * Read an entire handshake message. Handshake messages arrive in
409 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
412 struct hm_header_st *msg_hdr;
414 unsigned long msg_len;
416 /* s3->tmp is used to store messages that are unexpected, caused
417 * by the absence of an optional handshake message */
418 if (s->s3->tmp.reuse_message)
420 s->s3->tmp.reuse_message=0;
421 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
423 al=SSL_AD_UNEXPECTED_MESSAGE;
424 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
428 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
429 s->init_num = (int)s->s3->tmp.message_size;
433 msg_hdr = &s->d1->r_msg_hdr;
434 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
437 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
438 if ( i == DTLS1_HM_BAD_FRAGMENT ||
439 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
441 else if ( i <= 0 && !*ok)
444 p = (unsigned char *)s->init_buf->data;
445 msg_len = msg_hdr->msg_len;
447 /* reconstruct message header */
448 *(p++) = msg_hdr->type;
450 s2n (msg_hdr->seq,p);
453 if (s->version != DTLS1_BAD_VER) {
454 p -= DTLS1_HM_HEADER_LENGTH;
455 msg_len += DTLS1_HM_HEADER_LENGTH;
458 ssl3_finish_mac(s, p, msg_len);
460 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
462 s, s->msg_callback_arg);
464 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
466 /* Don't change sequence numbers while listening */
468 s->d1->handshake_read_seq++;
470 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
474 ssl3_send_alert(s,SSL3_AL_FATAL,al);
480 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
482 size_t frag_off,frag_len,msg_len;
484 msg_len = msg_hdr->msg_len;
485 frag_off = msg_hdr->frag_off;
486 frag_len = msg_hdr->frag_len;
488 /* sanity checking */
489 if ( (frag_off+frag_len) > msg_len)
491 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
492 return SSL_AD_ILLEGAL_PARAMETER;
495 if ( (frag_off+frag_len) > (unsigned long)max)
497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
498 return SSL_AD_ILLEGAL_PARAMETER;
501 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
503 /* msg_len is limited to 2^24, but is effectively checked
504 * against max above */
505 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
507 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
508 return SSL_AD_INTERNAL_ERROR;
511 s->s3->tmp.message_size = msg_len;
512 s->d1->r_msg_hdr.msg_len = msg_len;
513 s->s3->tmp.message_type = msg_hdr->type;
514 s->d1->r_msg_hdr.type = msg_hdr->type;
515 s->d1->r_msg_hdr.seq = msg_hdr->seq;
517 else if (msg_len != s->d1->r_msg_hdr.msg_len)
519 /* They must be playing with us! BTW, failure to enforce
520 * upper limit would open possibility for buffer overrun. */
521 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
522 return SSL_AD_ILLEGAL_PARAMETER;
525 return 0; /* no error */
530 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
532 /* (0) check whether the desired fragment is available
534 * (1) copy over the fragment to s->init_buf->data[]
535 * (2) update s->init_num
542 item = pqueue_peek(s->d1->buffered_messages);
546 frag = (hm_fragment *)item->data;
548 /* Don't return if reassembly still in progress */
549 if (frag->reassembly != NULL)
552 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
554 unsigned long frag_len = frag->msg_header.frag_len;
555 pqueue_pop(s->d1->buffered_messages);
557 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
559 if (al==0) /* no alert */
561 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
562 memcpy(&p[frag->msg_header.frag_off],
563 frag->fragment,frag->msg_header.frag_len);
566 dtls1_hm_fragment_free(frag);
575 ssl3_send_alert(s,SSL3_AL_FATAL,al);
586 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
588 hm_fragment *frag = NULL;
590 int i = -1, is_complete;
591 unsigned char seq64be[8];
592 unsigned long frag_len = msg_hdr->frag_len, max_len;
594 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
597 /* Determine maximum allowed message size. Depends on (user set)
598 * maximum certificate length, but 16k is minimum.
600 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
601 max_len = s->max_cert_list;
603 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
605 if ((msg_hdr->frag_off+frag_len) > max_len)
608 /* Try to find item in queue */
609 memset(seq64be,0,sizeof(seq64be));
610 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
611 seq64be[7] = (unsigned char) msg_hdr->seq;
612 item = pqueue_find(s->d1->buffered_messages, seq64be);
616 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
619 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
620 frag->msg_header.frag_len = frag->msg_header.msg_len;
621 frag->msg_header.frag_off = 0;
624 frag = (hm_fragment*) item->data;
626 /* If message is already reassembled, this must be a
627 * retransmit and can be dropped.
629 if (frag->reassembly == NULL)
631 unsigned char devnull [256];
635 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
637 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
641 return DTLS1_HM_FRAGMENT_RETRY;
644 /* read the body of the fragment (header has already been read */
645 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
646 frag->fragment + msg_hdr->frag_off,frag_len,0);
647 if (i<=0 || (unsigned long)i!=frag_len)
650 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
651 (long)(msg_hdr->frag_off + frag_len));
653 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
658 OPENSSL_free(frag->reassembly);
659 frag->reassembly = NULL;
664 memset(seq64be,0,sizeof(seq64be));
665 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
666 seq64be[7] = (unsigned char)(msg_hdr->seq);
668 item = pitem_new(seq64be, frag);
675 pqueue_insert(s->d1->buffered_messages, item);
678 return DTLS1_HM_FRAGMENT_RETRY;
681 if (frag != NULL) dtls1_hm_fragment_free(frag);
682 if (item != NULL) OPENSSL_free(item);
689 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
692 hm_fragment *frag = NULL;
694 unsigned char seq64be[8];
695 unsigned long frag_len = msg_hdr->frag_len;
697 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
700 /* Try to find item in queue, to prevent duplicate entries */
701 memset(seq64be,0,sizeof(seq64be));
702 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
703 seq64be[7] = (unsigned char) msg_hdr->seq;
704 item = pqueue_find(s->d1->buffered_messages, seq64be);
706 /* If we already have an entry and this one is a fragment,
707 * don't discard it and rather try to reassemble it.
709 if (item != NULL && frag_len < msg_hdr->msg_len)
712 /* Discard the message if sequence number was already there, is
713 * too far in the future, already in the queue or if we received
714 * a FINISHED before the SERVER_HELLO, which then must be a stale
717 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
718 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
719 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
721 unsigned char devnull [256];
725 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
727 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
734 if (frag_len && frag_len < msg_hdr->msg_len)
735 return dtls1_reassemble_fragment(s, msg_hdr, ok);
737 frag = dtls1_hm_fragment_new(frag_len, 0);
741 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
745 /* read the body of the fragment (header has already been read */
746 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
747 frag->fragment,frag_len,0);
748 if (i<=0 || (unsigned long)i!=frag_len)
752 memset(seq64be,0,sizeof(seq64be));
753 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
754 seq64be[7] = (unsigned char)(msg_hdr->seq);
756 item = pitem_new(seq64be, frag);
760 pqueue_insert(s->d1->buffered_messages, item);
763 return DTLS1_HM_FRAGMENT_RETRY;
766 if ( frag != NULL) dtls1_hm_fragment_free(frag);
767 if ( item != NULL) OPENSSL_free(item);
774 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
776 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
777 unsigned long len, frag_off, frag_len;
779 struct hm_header_st msg_hdr;
781 /* see if we have the required fragment already */
782 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
784 if (*ok) s->init_num = frag_len;
788 /* read handshake message header */
789 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
790 DTLS1_HM_HEADER_LENGTH, 0);
791 if (i <= 0) /* nbio, or an error */
793 s->rwstate=SSL_READING;
797 /* Handshake fails if message header is incomplete */
798 if (i != DTLS1_HM_HEADER_LENGTH)
800 al=SSL_AD_UNEXPECTED_MESSAGE;
801 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
805 /* parse the message fragment header */
806 dtls1_get_message_header(wire, &msg_hdr);
809 * if this is a future (or stale) message it gets buffered
810 * (or dropped)--no further processing at this time
811 * While listening, we accept seq 1 (ClientHello with cookie)
812 * although we're still expecting seq 0 (ClientHello)
814 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
815 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
817 len = msg_hdr.msg_len;
818 frag_off = msg_hdr.frag_off;
819 frag_len = msg_hdr.frag_len;
821 if (frag_len && frag_len < len)
822 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
824 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
825 wire[0] == SSL3_MT_HELLO_REQUEST)
827 /* The server may always send 'Hello Request' messages --
828 * we are doing a handshake anyway now, so ignore them
829 * if their format is correct. Does not count for
831 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
834 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
835 wire, DTLS1_HM_HEADER_LENGTH, s,
836 s->msg_callback_arg);
839 return dtls1_get_message_fragment(s, st1, stn,
842 else /* Incorrectly formated Hello request */
844 al=SSL_AD_UNEXPECTED_MESSAGE;
845 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
850 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
853 /* XDTLS: ressurect this when restart is in place */
858 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
860 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
861 &p[frag_off],frag_len,0);
862 /* XDTLS: fix this--message fragments cannot span multiple packets */
865 s->rwstate=SSL_READING;
873 /* XDTLS: an incorrectly formatted fragment should cause the
874 * handshake to fail */
875 if (i != (int)frag_len)
877 al=SSL3_AD_ILLEGAL_PARAMETER;
878 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
884 /* Note that s->init_num is *not* used as current offset in
885 * s->init_buf->data, but as a counter summing up fragments'
886 * lengths: as soon as they sum up to handshake packet
887 * length, we assume we have got all the fragments. */
888 s->init_num = frag_len;
892 ssl3_send_alert(s,SSL3_AL_FATAL,al);
899 /* for these 2 messages, we need to
900 * ssl->enc_read_ctx re-init
901 * ssl->s3->read_sequence zero
902 * ssl->s3->read_mac_secret re-init
903 * ssl->session->read_sym_enc assign
904 * ssl->session->read_compression assign
905 * ssl->session->read_hash assign
907 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
913 p=(unsigned char *)s->init_buf->data;
915 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
916 s->init_num=DTLS1_CCS_HEADER_LENGTH;
918 if (s->version == DTLS1_BAD_VER) {
919 s->d1->next_handshake_write_seq++;
920 s2n(s->d1->handshake_write_seq,p);
926 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
927 s->d1->handshake_write_seq, 0, 0);
929 /* buffer the message to handle re-xmits */
930 dtls1_buffer_message(s, 1);
935 /* SSL3_ST_CW_CHANGE_B */
936 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
939 int dtls1_read_failed(SSL *s, int code)
943 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
947 if (!dtls1_is_timer_expired(s))
949 /* not a timeout, none of our business,
950 let higher layers handle this. in fact it's probably an error */
954 #ifndef OPENSSL_NO_HEARTBEATS
955 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */
957 if (!SSL_in_init(s)) /* done, no need to send a retransmit */
960 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
964 #if 0 /* for now, each alert contains only one record number */
965 item = pqueue_peek(state->rcvd_records);
968 /* send an alert immediately for all the missing records */
973 #if 0 /* no more alert sending, just retransmit the last set of messages */
974 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
975 ssl3_send_alert(s,SSL3_AL_WARNING,
976 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
979 return dtls1_handle_timeout(s);
983 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
985 /* The index of the retransmission queue actually is the message sequence number,
986 * since the queue only contains messages of a single handshake. However, the
987 * ChangeCipherSpec has no message sequence number and so using only the sequence
988 * will result in the CCS and Finished having the same index. To prevent this,
989 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
990 * This does not only differ CSS and Finished, it also maintains the order of the
991 * index (important for priority queues) and fits in the unsigned short variable.
993 return seq * 2 - is_ccs;
997 dtls1_retransmit_buffered_messages(SSL *s)
999 pqueue sent = s->d1->sent_messages;
1005 iter = pqueue_iterator(sent);
1007 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1009 frag = (hm_fragment *)item->data;
1010 if ( dtls1_retransmit_message(s,
1011 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1012 0, &found) <= 0 && found)
1014 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1023 dtls1_buffer_message(SSL *s, int is_ccs)
1027 unsigned char seq64be[8];
1029 /* this function is called immediately after a message has
1030 * been serialized */
1031 OPENSSL_assert(s->init_off == 0);
1033 frag = dtls1_hm_fragment_new(s->init_num, 0);
1035 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1039 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1040 DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1044 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1045 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1048 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1049 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1050 frag->msg_header.type = s->d1->w_msg_hdr.type;
1051 frag->msg_header.frag_off = 0;
1052 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1053 frag->msg_header.is_ccs = is_ccs;
1055 /* save current state*/
1056 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1057 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1058 frag->msg_header.saved_retransmit_state.compress = s->compress;
1059 frag->msg_header.saved_retransmit_state.session = s->session;
1060 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1062 memset(seq64be,0,sizeof(seq64be));
1063 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1064 frag->msg_header.is_ccs)>>8);
1065 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1066 frag->msg_header.is_ccs));
1068 item = pitem_new(seq64be, frag);
1071 dtls1_hm_fragment_free(frag);
1076 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1077 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1078 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1081 pqueue_insert(s->d1->sent_messages, item);
1086 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1090 /* XDTLS: for now assuming that read/writes are blocking */
1093 unsigned long header_length;
1094 unsigned char seq64be[8];
1095 struct dtls1_retransmit_state saved_state;
1096 unsigned char save_write_sequence[8];
1099 OPENSSL_assert(s->init_num == 0);
1100 OPENSSL_assert(s->init_off == 0);
1103 /* XDTLS: the requested message ought to be found, otherwise error */
1104 memset(seq64be,0,sizeof(seq64be));
1105 seq64be[6] = (unsigned char)(seq>>8);
1106 seq64be[7] = (unsigned char)seq;
1108 item = pqueue_find(s->d1->sent_messages, seq64be);
1111 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1117 frag = (hm_fragment *)item->data;
1119 if ( frag->msg_header.is_ccs)
1120 header_length = DTLS1_CCS_HEADER_LENGTH;
1122 header_length = DTLS1_HM_HEADER_LENGTH;
1124 memcpy(s->init_buf->data, frag->fragment,
1125 frag->msg_header.msg_len + header_length);
1126 s->init_num = frag->msg_header.msg_len + header_length;
1128 dtls1_set_message_header_int(s, frag->msg_header.type,
1129 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1130 frag->msg_header.frag_len);
1132 /* save current state */
1133 saved_state.enc_write_ctx = s->enc_write_ctx;
1134 saved_state.write_hash = s->write_hash;
1135 saved_state.compress = s->compress;
1136 saved_state.session = s->session;
1137 saved_state.epoch = s->d1->w_epoch;
1138 saved_state.epoch = s->d1->w_epoch;
1140 s->d1->retransmitting = 1;
1142 /* restore state in which the message was originally sent */
1143 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1144 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1145 s->compress = frag->msg_header.saved_retransmit_state.compress;
1146 s->session = frag->msg_header.saved_retransmit_state.session;
1147 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1149 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1151 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1152 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1155 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1156 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1158 /* restore current state */
1159 s->enc_write_ctx = saved_state.enc_write_ctx;
1160 s->write_hash = saved_state.write_hash;
1161 s->compress = saved_state.compress;
1162 s->session = saved_state.session;
1163 s->d1->w_epoch = saved_state.epoch;
1165 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1167 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1168 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1171 s->d1->retransmitting = 0;
1173 (void)BIO_flush(SSL_get_wbio(s));
1177 /* call this function when the buffered messages are no longer needed */
1179 dtls1_clear_record_buffer(SSL *s)
1183 for(item = pqueue_pop(s->d1->sent_messages);
1184 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1186 dtls1_hm_fragment_free((hm_fragment *)item->data);
1193 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1194 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1196 /* Don't change sequence numbers while listening */
1197 if (frag_off == 0 && !s->d1->listen)
1199 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1200 s->d1->next_handshake_write_seq++;
1203 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1204 frag_off, frag_len);
1206 return p += DTLS1_HM_HEADER_LENGTH;
1210 /* don't actually do the writing, wait till the MTU has been retrieved */
1212 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1213 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1214 unsigned long frag_len)
1216 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1219 msg_hdr->msg_len = len;
1220 msg_hdr->seq = seq_num;
1221 msg_hdr->frag_off = frag_off;
1222 msg_hdr->frag_len = frag_len;
1226 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1227 unsigned long frag_len)
1229 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1231 msg_hdr->frag_off = frag_off;
1232 msg_hdr->frag_len = frag_len;
1235 static unsigned char *
1236 dtls1_write_message_header(SSL *s, unsigned char *p)
1238 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1240 *p++ = msg_hdr->type;
1241 l2n3(msg_hdr->msg_len, p);
1243 s2n(msg_hdr->seq, p);
1244 l2n3(msg_hdr->frag_off, p);
1245 l2n3(msg_hdr->frag_len, p);
1253 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1254 sizeof(g_probable_mtu[0])) - 1]);
1258 dtls1_guess_mtu(unsigned int curr_mtu)
1262 if ( curr_mtu == 0 )
1263 return g_probable_mtu[0] ;
1265 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1266 if ( curr_mtu > g_probable_mtu[i])
1267 return g_probable_mtu[i];
1273 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1275 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1276 msg_hdr->type = *(data++);
1277 n2l3(data, msg_hdr->msg_len);
1279 n2s(data, msg_hdr->seq);
1280 n2l3(data, msg_hdr->frag_off);
1281 n2l3(data, msg_hdr->frag_len);
1285 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1287 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1289 ccs_hdr->type = *(data++);
1292 int dtls1_shutdown(SSL *s)
1295 #ifndef OPENSSL_NO_SCTP
1296 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1297 !(s->shutdown & SSL_SENT_SHUTDOWN))
1299 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1300 if (ret < 0) return -1;
1303 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1306 ret = ssl3_shutdown(s);
1307 #ifndef OPENSSL_NO_SCTP
1308 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1313 #ifndef OPENSSL_NO_HEARTBEATS
1315 dtls1_process_heartbeat(SSL *s)
1317 unsigned char *p = &s->s3->rrec.data[0], *pl;
1318 unsigned short hbtype;
1319 unsigned int payload;
1320 unsigned int padding = 16; /* Use minimum padding */
1322 /* Read type and payload length first */
1327 if (s->msg_callback)
1328 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1329 &s->s3->rrec.data[0], s->s3->rrec.length,
1330 s, s->msg_callback_arg);
1332 if (hbtype == TLS1_HB_REQUEST)
1334 unsigned char *buffer, *bp;
1337 /* Allocate memory for the response, size is 1 byte
1338 * message type, plus 2 bytes payload length, plus
1339 * payload, plus padding
1341 buffer = OPENSSL_malloc(1 + 2 + payload + padding);
1344 /* Enter response type, length and copy payload */
1345 *bp++ = TLS1_HB_RESPONSE;
1347 memcpy(bp, pl, payload);
1349 /* Random padding */
1350 RAND_pseudo_bytes(bp, padding);
1352 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
1354 if (r >= 0 && s->msg_callback)
1355 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1356 buffer, 3 + payload + padding,
1357 s, s->msg_callback_arg);
1359 OPENSSL_free(buffer);
1364 else if (hbtype == TLS1_HB_RESPONSE)
1368 /* We only send sequence numbers (2 bytes unsigned int),
1369 * and 16 random bytes, so we just try to read the
1370 * sequence number */
1373 if (payload == 18 && seq == s->tlsext_hb_seq)
1375 dtls1_stop_timer(s);
1377 s->tlsext_hb_pending = 0;
1385 dtls1_heartbeat(SSL *s)
1387 unsigned char *buf, *p;
1389 unsigned int payload = 18; /* Sequence number + random bytes */
1390 unsigned int padding = 16; /* Use minimum padding */
1392 /* Only send if peer supports and accepts HB requests... */
1393 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1394 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1396 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1400 /* ...and there is none in flight yet... */
1401 if (s->tlsext_hb_pending)
1403 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1407 /* ...and no handshake in progress. */
1408 if (SSL_in_init(s) || s->in_handshake)
1410 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1414 /* Check if padding is too long, payload and padding
1415 * must not exceed 2^14 - 3 = 16381 bytes in total.
1417 OPENSSL_assert(payload + padding <= 16381);
1419 /* Create HeartBeat message, we just use a sequence number
1420 * as payload to distuingish different messages and add
1421 * some random stuff.
1422 * - Message Type, 1 byte
1423 * - Payload Length, 2 bytes (unsigned int)
1424 * - Payload, the sequence number (2 bytes uint)
1425 * - Payload, random bytes (16 bytes uint)
1428 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1431 *p++ = TLS1_HB_REQUEST;
1432 /* Payload length (18 bytes here) */
1434 /* Sequence number */
1435 s2n(s->tlsext_hb_seq, p);
1436 /* 16 random bytes */
1437 RAND_pseudo_bytes(p, 16);
1439 /* Random padding */
1440 RAND_pseudo_bytes(p, padding);
1442 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1445 if (s->msg_callback)
1446 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1447 buf, 3 + payload + padding,
1448 s, s->msg_callback_arg);
1450 dtls1_start_timer(s);
1451 s->tlsext_hb_pending = 1;