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;
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);
231 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
232 DTLS1_RT_HEADER_LENGTH;
234 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
236 /* grr.. we could get an error if MTU picked was wrong */
237 ret = BIO_flush(SSL_get_wbio(s));
240 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
243 if ( s->init_num > curr_mtu)
249 /* XDTLS: this function is too long. split out the CCS part */
250 if ( type == SSL3_RT_HANDSHAKE)
252 if ( s->init_off != 0)
254 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
255 s->init_off -= DTLS1_HM_HEADER_LENGTH;
256 s->init_num += DTLS1_HM_HEADER_LENGTH;
258 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
259 if ( len <= DTLS1_HM_HEADER_LENGTH)
260 len += DTLS1_HM_HEADER_LENGTH;
263 dtls1_fix_message_header(s, frag_off,
264 len - DTLS1_HM_HEADER_LENGTH);
266 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
268 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
271 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
275 /* might need to update MTU here, but we don't know
276 * which previous packet caused the failure -- so can't
277 * really retransmit anything. continue as if everything
278 * is fine and wait for an alert to handle the
281 if ( BIO_ctrl(SSL_get_wbio(s),
282 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
283 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
284 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
291 /* bad if this assert fails, only part of the handshake
292 * message got sent. but why would this happen? */
293 OPENSSL_assert(len == (unsigned int)ret);
295 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
297 /* should not be done for 'Hello Request's, but in that case
298 * we'll ignore the result anyway */
299 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
300 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
305 /* reconstruct message header is if it
306 * is being sent in single fragment */
307 *p++ = msg_hdr->type;
308 l2n3(msg_hdr->msg_len,p);
309 s2n (msg_hdr->seq,p);
311 l2n3(msg_hdr->msg_len,p);
312 p -= DTLS1_HM_HEADER_LENGTH;
317 p += DTLS1_HM_HEADER_LENGTH;
318 xlen = ret - DTLS1_HM_HEADER_LENGTH;
321 ssl3_finish_mac(s, p, xlen);
324 if (ret == s->init_num)
327 s->msg_callback(1, s->version, type, s->init_buf->data,
328 (size_t)(s->init_off + s->init_num), s,
329 s->msg_callback_arg);
331 s->init_off = 0; /* done writing this message */
338 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
345 /* Obtain handshake message of message type 'mt' (any if mt == -1),
346 * maximum acceptable body length 'max'.
347 * Read an entire handshake message. Handshake messages arrive in
350 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
353 struct hm_header_st *msg_hdr;
355 /* s3->tmp is used to store messages that are unexpected, caused
356 * by the absence of an optional handshake message */
357 if (s->s3->tmp.reuse_message)
359 s->s3->tmp.reuse_message=0;
360 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
362 al=SSL_AD_UNEXPECTED_MESSAGE;
363 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
367 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
368 s->init_num = (int)s->s3->tmp.message_size;
372 msg_hdr = &s->d1->r_msg_hdr;
375 if ( msg_hdr->frag_off == 0)
377 /* s->d1->r_message_header.msg_len = 0; */
378 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
381 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
382 if ( i == DTLS1_HM_BAD_FRAGMENT ||
383 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
385 else if ( i <= 0 && !*ok)
388 /* Note that s->init_sum is used as a counter summing
389 * up fragments' lengths: as soon as they sum up to
390 * handshake packet length, we assume we have got all
391 * the fragments. Overlapping fragments would cause
392 * premature termination, so we don't expect overlaps.
393 * Well, handling overlaps would require something more
394 * drastic. Indeed, as it is now there is no way to
395 * tell if out-of-order fragment from the middle was
396 * the last. '>=' is the best/least we can do to control
397 * the potential damage caused by malformed overlaps. */
398 if ((unsigned int)s->init_num >= msg_hdr->msg_len)
400 unsigned char *p = (unsigned char *)s->init_buf->data;
401 unsigned long msg_len = msg_hdr->msg_len;
403 /* reconstruct message header as if it was
404 * sent in single fragment */
405 *(p++) = msg_hdr->type;
407 s2n (msg_hdr->seq,p);
410 p -= DTLS1_HM_HEADER_LENGTH;
411 msg_len += DTLS1_HM_HEADER_LENGTH;
413 ssl3_finish_mac(s, p, msg_len);
415 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
417 s, s->msg_callback_arg);
419 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
421 s->d1->handshake_read_seq++;
422 /* we just read a handshake message from the other side:
423 * this means that we don't need to retransmit of the
425 * XDTLS: may be able clear out this
426 * buffer a little sooner (i.e if an out-of-order
427 * handshake message/record is received at the record
429 * XDTLS: exception is that the server needs to
430 * know that change cipher spec and finished messages
431 * have been received by the client before clearing this
432 * buffer. this can simply be done by waiting for the
433 * first data segment, but is there a better way? */
434 dtls1_clear_record_buffer(s);
436 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
440 msg_hdr->frag_off = i;
444 ssl3_send_alert(s,SSL3_AL_FATAL,al);
450 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
452 size_t frag_off,frag_len,msg_len;
454 msg_len = msg_hdr->msg_len;
455 frag_off = msg_hdr->frag_off;
456 frag_len = msg_hdr->frag_len;
458 /* sanity checking */
459 if ( (frag_off+frag_len) > msg_len)
461 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
462 return SSL_AD_ILLEGAL_PARAMETER;
465 if ( (frag_off+frag_len) > (unsigned long)max)
467 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
468 return SSL_AD_ILLEGAL_PARAMETER;
471 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
473 /* msg_len is limited to 2^24, but is effectively checked
474 * against max above */
475 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
477 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
478 return SSL_AD_INTERNAL_ERROR;
481 s->s3->tmp.message_size = msg_len;
482 s->d1->r_msg_hdr.msg_len = msg_len;
483 s->s3->tmp.message_type = msg_hdr->type;
484 s->d1->r_msg_hdr.type = msg_hdr->type;
485 s->d1->r_msg_hdr.seq = msg_hdr->seq;
487 else if (msg_len != s->d1->r_msg_hdr.msg_len)
489 /* They must be playing with us! BTW, failure to enforce
490 * upper limit would open possibility for buffer overrun. */
491 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
492 return SSL_AD_ILLEGAL_PARAMETER;
495 return 0; /* no error */
500 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
502 /* (0) check whether the desired fragment is available
504 * (1) copy over the fragment to s->init_buf->data[]
505 * (2) update s->init_num
512 item = pqueue_peek(s->d1->buffered_messages);
516 frag = (hm_fragment *)item->data;
518 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
520 pqueue_pop(s->d1->buffered_messages);
522 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
524 if (al==0) /* no alert */
526 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
527 memcpy(&p[frag->msg_header.frag_off],
528 frag->fragment,frag->msg_header.frag_len);
531 dtls1_hm_fragment_free(frag);
537 return frag->msg_header.frag_len;
540 ssl3_send_alert(s,SSL3_AL_FATAL,al);
551 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
554 hm_fragment *frag = NULL;
556 unsigned char seq64be[8];
557 unsigned long frag_len = msg_hdr->frag_len;
559 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
562 if (msg_hdr->seq <= s->d1->handshake_read_seq)
564 unsigned char devnull [256];
568 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
570 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
578 frag = dtls1_hm_fragment_new(frag_len);
582 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
584 /* read the body of the fragment (header has already been read */
585 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
586 frag->fragment,frag_len,0);
587 if (i<=0 || (unsigned long)i!=frag_len)
590 memset(seq64be,0,sizeof(seq64be));
591 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
592 seq64be[7] = (unsigned char)(msg_hdr->seq);
594 item = pitem_new(seq64be, frag);
598 pqueue_insert(s->d1->buffered_messages, item);
601 return DTLS1_HM_FRAGMENT_RETRY;
604 if ( frag != NULL) dtls1_hm_fragment_free(frag);
605 if ( item != NULL) OPENSSL_free(item);
612 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
614 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
615 unsigned long l, frag_off, frag_len;
617 struct hm_header_st msg_hdr;
619 /* see if we have the required fragment already */
620 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
622 if (*ok) s->init_num += frag_len;
626 /* read handshake message header */
627 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
628 DTLS1_HM_HEADER_LENGTH, 0);
629 if (i <= 0) /* nbio, or an error */
631 s->rwstate=SSL_READING;
635 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
637 /* parse the message fragment header */
638 dtls1_get_message_header(wire, &msg_hdr);
641 * if this is a future (or stale) message it gets buffered
642 * (or dropped)--no further processing at this time
644 if ( msg_hdr.seq != s->d1->handshake_read_seq)
645 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
648 frag_off = msg_hdr.frag_off;
649 frag_len = msg_hdr.frag_len;
651 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
652 wire[0] == SSL3_MT_HELLO_REQUEST)
654 /* The server may always send 'Hello Request' messages --
655 * we are doing a handshake anyway now, so ignore them
656 * if their format is correct. Does not count for
658 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
661 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
662 wire, DTLS1_HM_HEADER_LENGTH, s,
663 s->msg_callback_arg);
666 return dtls1_get_message_fragment(s, st1, stn,
669 else /* Incorrectly formated Hello request */
671 al=SSL_AD_UNEXPECTED_MESSAGE;
672 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
677 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
680 /* XDTLS: ressurect this when restart is in place */
685 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
687 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
688 &p[frag_off],frag_len,0);
689 /* XDTLS: fix this--message fragments cannot span multiple packets */
692 s->rwstate=SSL_READING;
700 /* XDTLS: an incorrectly formatted fragment should cause the
701 * handshake to fail */
702 OPENSSL_assert(i == (int)frag_len);
706 /* Note that s->init_num is *not* used as current offset in
707 * s->init_buf->data, but as a counter summing up fragments'
708 * lengths: as soon as they sum up to handshake packet
709 * length, we assume we have got all the fragments. */
710 s->init_num += frag_len;
714 ssl3_send_alert(s,SSL3_AL_FATAL,al);
721 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
729 d=(unsigned char *)s->init_buf->data;
730 p= &(d[DTLS1_HM_HEADER_LENGTH]);
732 i=s->method->ssl3_enc->final_finish_mac(s,
733 sender,slen,s->s3->tmp.finish_md);
734 s->s3->tmp.finish_md_len = i;
735 memcpy(p, s->s3->tmp.finish_md, i);
739 #ifdef OPENSSL_SYS_WIN16
740 /* MSVC 1.5 does not clear the top bytes of the word unless
746 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
747 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
750 /* buffer the message to handle re-xmits */
751 dtls1_buffer_message(s, 0);
756 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
757 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
760 /* for these 2 messages, we need to
761 * ssl->enc_read_ctx re-init
762 * ssl->s3->read_sequence zero
763 * ssl->s3->read_mac_secret re-init
764 * ssl->session->read_sym_enc assign
765 * ssl->session->read_compression assign
766 * ssl->session->read_hash assign
768 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
774 p=(unsigned char *)s->init_buf->data;
776 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
777 s->init_num=DTLS1_CCS_HEADER_LENGTH;
780 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
781 s->d1->handshake_write_seq, 0, 0);
783 /* buffer the message to handle re-xmits */
784 dtls1_buffer_message(s, 1);
789 /* SSL3_ST_CW_CHANGE_B */
790 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
793 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
797 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
799 X509_STORE_CTX xs_ctx;
802 /* TLSv1 sends a chain with nothing in it, instead of an alert */
804 if (!BUF_MEM_grow_clean(buf,10))
806 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
811 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
813 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
820 if (!BUF_MEM_grow_clean(buf,(n+l+3)))
822 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
825 p=(unsigned char *)&(buf->data[l]);
829 if (X509_NAME_cmp(X509_get_subject_name(x),
830 X509_get_issuer_name(x)) == 0) break;
832 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
833 X509_get_issuer_name(x),&obj);
836 /* Count is one too high since the X509_STORE_get uped the
841 X509_STORE_CTX_cleanup(&xs_ctx);
844 /* Thawte special :-) */
845 if (s->ctx->extra_certs != NULL)
846 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
848 x=sk_X509_value(s->ctx->extra_certs,i);
850 if (!BUF_MEM_grow_clean(buf,(n+l+3)))
852 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
855 p=(unsigned char *)&(buf->data[l]);
861 l-= (3 + DTLS1_HM_HEADER_LENGTH);
863 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
866 p=(unsigned char *)&(buf->data[0]);
867 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
869 l+=DTLS1_HM_HEADER_LENGTH;
873 int dtls1_read_failed(SSL *s, int code)
881 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
885 bio = SSL_get_rbio(s);
886 if ( ! BIO_dgram_recv_timedout(bio))
888 /* not a timeout, none of our business,
889 let higher layers handle this. in fact it's probably an error */
893 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */
895 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
900 state->timeout.num_alerts++;
901 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
903 /* fail the connection, enough alerts have been sent */
904 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
908 state->timeout.read_timeouts++;
909 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
912 state->timeout.read_timeouts = 1;
916 #if 0 /* for now, each alert contains only one record number */
917 item = pqueue_peek(state->rcvd_records);
920 /* send an alert immediately for all the missing records */
925 #if 0 /* no more alert sending, just retransmit the last set of messages */
927 ssl3_send_alert(s,SSL3_AL_WARNING,
928 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
931 return dtls1_retransmit_buffered_messages(s) ;
935 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
937 /* The index of the retransmission queue actually is the message sequence number,
938 * since the queue only contains messages of a single handshake. However, the
939 * ChangeCipherSpec has no message sequence number and so using only the sequence
940 * will result in the CCS and Finished having the same index. To prevent this,
941 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
942 * This does not only differ CSS and Finished, it also maintains the order of the
943 * index (important for priority queues) and fits in the unsigned short variable.
945 return seq * 2 - is_ccs;
949 dtls1_retransmit_buffered_messages(SSL *s)
951 pqueue sent = s->d1->sent_messages;
957 iter = pqueue_iterator(sent);
959 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
961 frag = (hm_fragment *)item->data;
962 if ( dtls1_retransmit_message(s,
963 dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
964 0, &found) <= 0 && found)
966 fprintf(stderr, "dtls1_retransmit_message() failed\n");
975 dtls1_buffer_message(SSL *s, int is_ccs)
979 unsigned char seq64be[8];
981 /* this function is called immediately after a message has
983 OPENSSL_assert(s->init_off == 0);
985 frag = dtls1_hm_fragment_new(s->init_num);
987 memcpy(frag->fragment, s->init_buf->data, s->init_num);
991 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
992 DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
996 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
997 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1000 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1001 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1002 frag->msg_header.type = s->d1->w_msg_hdr.type;
1003 frag->msg_header.frag_off = 0;
1004 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1005 frag->msg_header.is_ccs = is_ccs;
1007 /* save current state*/
1008 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1009 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1010 frag->msg_header.saved_retransmit_state.compress = s->compress;
1011 frag->msg_header.saved_retransmit_state.session = s->session;
1012 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1014 memset(seq64be,0,sizeof(seq64be));
1015 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1016 frag->msg_header.is_ccs)>>8);
1017 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1018 frag->msg_header.is_ccs));
1020 item = pitem_new(seq64be, frag);
1023 dtls1_hm_fragment_free(frag);
1028 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1029 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1030 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1033 pqueue_insert(s->d1->sent_messages, item);
1038 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1042 /* XDTLS: for now assuming that read/writes are blocking */
1045 unsigned long header_length;
1046 unsigned char seq64be[8];
1047 struct dtls1_retransmit_state saved_state;
1048 unsigned char save_write_sequence[8];
1051 OPENSSL_assert(s->init_num == 0);
1052 OPENSSL_assert(s->init_off == 0);
1055 /* XDTLS: the requested message ought to be found, otherwise error */
1056 memset(seq64be,0,sizeof(seq64be));
1057 seq64be[6] = (unsigned char)(seq>>8);
1058 seq64be[7] = (unsigned char)seq;
1060 item = pqueue_find(s->d1->sent_messages, seq64be);
1063 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1069 frag = (hm_fragment *)item->data;
1071 if ( frag->msg_header.is_ccs)
1072 header_length = DTLS1_CCS_HEADER_LENGTH;
1074 header_length = DTLS1_HM_HEADER_LENGTH;
1076 memcpy(s->init_buf->data, frag->fragment,
1077 frag->msg_header.msg_len + header_length);
1078 s->init_num = frag->msg_header.msg_len + header_length;
1080 dtls1_set_message_header_int(s, frag->msg_header.type,
1081 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1082 frag->msg_header.frag_len);
1084 /* save current state */
1085 saved_state.enc_write_ctx = s->enc_write_ctx;
1086 saved_state.write_hash = s->write_hash;
1087 saved_state.compress = s->compress;
1088 saved_state.session = s->session;
1089 saved_state.epoch = s->d1->w_epoch;
1090 saved_state.epoch = s->d1->w_epoch;
1092 s->d1->retransmitting = 1;
1094 /* restore state in which the message was originally sent */
1095 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1096 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1097 s->compress = frag->msg_header.saved_retransmit_state.compress;
1098 s->session = frag->msg_header.saved_retransmit_state.session;
1099 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1101 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1103 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1104 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1107 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1108 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1110 /* restore current state */
1111 s->enc_write_ctx = saved_state.enc_write_ctx;
1112 s->write_hash = saved_state.write_hash;
1113 s->compress = saved_state.compress;
1114 s->session = saved_state.session;
1115 s->d1->w_epoch = saved_state.epoch;
1117 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1119 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1120 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1123 s->d1->retransmitting = 0;
1125 (void)BIO_flush(SSL_get_wbio(s));
1129 /* call this function when the buffered messages are no longer needed */
1131 dtls1_clear_record_buffer(SSL *s)
1135 for(item = pqueue_pop(s->d1->sent_messages);
1136 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1138 dtls1_hm_fragment_free((hm_fragment *)item->data);
1145 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1146 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1150 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1151 s->d1->next_handshake_write_seq++;
1154 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1155 frag_off, frag_len);
1157 return p += DTLS1_HM_HEADER_LENGTH;
1161 /* don't actually do the writing, wait till the MTU has been retrieved */
1163 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1164 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1165 unsigned long frag_len)
1167 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1170 msg_hdr->msg_len = len;
1171 msg_hdr->seq = seq_num;
1172 msg_hdr->frag_off = frag_off;
1173 msg_hdr->frag_len = frag_len;
1177 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1178 unsigned long frag_len)
1180 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1182 msg_hdr->frag_off = frag_off;
1183 msg_hdr->frag_len = frag_len;
1186 static unsigned char *
1187 dtls1_write_message_header(SSL *s, unsigned char *p)
1189 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1191 *p++ = msg_hdr->type;
1192 l2n3(msg_hdr->msg_len, p);
1194 s2n(msg_hdr->seq, p);
1195 l2n3(msg_hdr->frag_off, p);
1196 l2n3(msg_hdr->frag_len, p);
1204 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1205 sizeof(g_probable_mtu[0])) - 1]);
1209 dtls1_guess_mtu(unsigned int curr_mtu)
1213 if ( curr_mtu == 0 )
1214 return g_probable_mtu[0] ;
1216 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1217 if ( curr_mtu > g_probable_mtu[i])
1218 return g_probable_mtu[i];
1224 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1226 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1227 msg_hdr->type = *(data++);
1228 n2l3(data, msg_hdr->msg_len);
1230 n2s(data, msg_hdr->seq);
1231 n2l3(data, msg_hdr->frag_off);
1232 n2l3(data, msg_hdr->frag_len);
1236 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1238 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1240 ccs_hdr->type = *(data++);