d1_lib.c revision 306230 
1/* ssl/d1_lib.c */
2/*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6/* ====================================================================
7 * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
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
19 *    distribution.
20 *
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/)"
25 *
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.
30 *
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.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
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 * ====================================================================
53 *
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).
57 *
58 */
59
60#include <stdio.h>
61#define USE_SOCKETS
62#include <openssl/objects.h>
63#include "ssl_locl.h"
64
65#if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
66# include <sys/timeb.h>
67#endif
68
69static void get_current_time(struct timeval *t);
70const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;
71int dtls1_listen(SSL *s, struct sockaddr *client);
72
73SSL3_ENC_METHOD DTLSv1_enc_data = {
74    dtls1_enc,
75    tls1_mac,
76    tls1_setup_key_block,
77    tls1_generate_master_secret,
78    tls1_change_cipher_state,
79    tls1_final_finish_mac,
80    TLS1_FINISH_MAC_LENGTH,
81    tls1_cert_verify_mac,
82    TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
83    TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
84    tls1_alert_code,
85};
86
87long dtls1_default_timeout(void)
88{
89    /*
90     * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
91     * http, the cache would over fill
92     */
93    return (60 * 60 * 2);
94}
95
96IMPLEMENT_dtls1_meth_func(dtlsv1_base_method,
97                          ssl_undefined_function,
98                          ssl_undefined_function, ssl_bad_method)
99
100int dtls1_new(SSL *s)
101{
102    DTLS1_STATE *d1;
103
104    if (!ssl3_new(s))
105        return (0);
106    if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)
107        return (0);
108    memset(d1, 0, sizeof *d1);
109
110    /* d1->handshake_epoch=0; */
111#if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
112    d1->bitmap.length = 64;
113#else
114    d1->bitmap.length = sizeof(d1->bitmap.map) * 8;
115#endif
116    pq_64bit_init(&(d1->bitmap.map));
117    pq_64bit_init(&(d1->bitmap.max_seq_num));
118
119    d1->next_bitmap.length = d1->bitmap.length;
120    pq_64bit_init(&(d1->next_bitmap.map));
121    pq_64bit_init(&(d1->next_bitmap.max_seq_num));
122
123    d1->unprocessed_rcds.q = pqueue_new();
124    d1->processed_rcds.q = pqueue_new();
125    d1->buffered_messages = pqueue_new();
126    d1->sent_messages = pqueue_new();
127    d1->buffered_app_data.q = pqueue_new();
128
129    if (s->server) {
130        d1->cookie_len = sizeof(s->d1->cookie);
131    }
132
133    if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q
134        || !d1->buffered_messages || !d1->sent_messages
135        || !d1->buffered_app_data.q) {
136        if (d1->unprocessed_rcds.q)
137            pqueue_free(d1->unprocessed_rcds.q);
138        if (d1->processed_rcds.q)
139            pqueue_free(d1->processed_rcds.q);
140        if (d1->buffered_messages)
141            pqueue_free(d1->buffered_messages);
142        if (d1->sent_messages)
143            pqueue_free(d1->sent_messages);
144        if (d1->buffered_app_data.q)
145            pqueue_free(d1->buffered_app_data.q);
146        OPENSSL_free(d1);
147        return (0);
148    }
149
150    s->d1 = d1;
151    s->method->ssl_clear(s);
152    return (1);
153}
154
155static void dtls1_clear_queues(SSL *s)
156{
157    pitem *item = NULL;
158    DTLS1_RECORD_DATA *rdata;
159
160    while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {
161        rdata = (DTLS1_RECORD_DATA *)item->data;
162        if (rdata->rbuf.buf) {
163            OPENSSL_free(rdata->rbuf.buf);
164        }
165        OPENSSL_free(item->data);
166        pitem_free(item);
167    }
168
169    while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {
170        rdata = (DTLS1_RECORD_DATA *)item->data;
171        if (rdata->rbuf.buf) {
172            OPENSSL_free(rdata->rbuf.buf);
173        }
174        OPENSSL_free(item->data);
175        pitem_free(item);
176    }
177
178    while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {
179        rdata = (DTLS1_RECORD_DATA *)item->data;
180        if (rdata->rbuf.buf) {
181            OPENSSL_free(rdata->rbuf.buf);
182        }
183        OPENSSL_free(item->data);
184        pitem_free(item);
185    }
186
187    dtls1_clear_received_buffer(s);
188    dtls1_clear_sent_buffer(s);
189}
190
191void dtls1_clear_received_buffer(SSL *s)
192{
193    pitem *item = NULL;
194    hm_fragment *frag = NULL;
195
196    while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
197        frag = (hm_fragment *)item->data;
198        OPENSSL_free(frag->fragment);
199        OPENSSL_free(frag);
200        pitem_free(item);
201    }
202}
203
204void dtls1_clear_sent_buffer(SSL *s)
205{
206    pitem *item = NULL;
207    hm_fragment *frag = NULL;
208
209    while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
210        frag = (hm_fragment *)item->data;
211        OPENSSL_free(frag->fragment);
212        OPENSSL_free(frag);
213        pitem_free(item);
214    }
215}
216
217
218void dtls1_free(SSL *s)
219{
220    ssl3_free(s);
221
222    dtls1_clear_queues(s);
223
224    pqueue_free(s->d1->unprocessed_rcds.q);
225    pqueue_free(s->d1->processed_rcds.q);
226    pqueue_free(s->d1->buffered_messages);
227    pqueue_free(s->d1->sent_messages);
228    pqueue_free(s->d1->buffered_app_data.q);
229
230    pq_64bit_free(&(s->d1->bitmap.map));
231    pq_64bit_free(&(s->d1->bitmap.max_seq_num));
232
233    pq_64bit_free(&(s->d1->next_bitmap.map));
234    pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
235
236    OPENSSL_free(s->d1);
237    s->d1 = NULL;
238}
239
240void dtls1_clear(SSL *s)
241{
242    pqueue unprocessed_rcds;
243    pqueue processed_rcds;
244    pqueue buffered_messages;
245    pqueue sent_messages;
246    pqueue buffered_app_data;
247    unsigned int mtu;
248
249    if (s->d1) {
250        unprocessed_rcds = s->d1->unprocessed_rcds.q;
251        processed_rcds = s->d1->processed_rcds.q;
252        buffered_messages = s->d1->buffered_messages;
253        sent_messages = s->d1->sent_messages;
254        buffered_app_data = s->d1->buffered_app_data.q;
255        mtu = s->d1->mtu;
256
257        dtls1_clear_queues(s);
258
259        pq_64bit_free(&(s->d1->bitmap.map));
260        pq_64bit_free(&(s->d1->bitmap.max_seq_num));
261
262        pq_64bit_free(&(s->d1->next_bitmap.map));
263        pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
264
265        memset(s->d1, 0, sizeof(*(s->d1)));
266
267        if (s->server) {
268            s->d1->cookie_len = sizeof(s->d1->cookie);
269        }
270
271        if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
272            s->d1->mtu = mtu;
273        }
274
275        s->d1->unprocessed_rcds.q = unprocessed_rcds;
276        s->d1->processed_rcds.q = processed_rcds;
277        s->d1->buffered_messages = buffered_messages;
278        s->d1->sent_messages = sent_messages;
279        s->d1->buffered_app_data.q = buffered_app_data;
280
281#if defined(OPENSSL_SYS_VMS) || defined(VMS_TEST)
282        s->d1->bitmap.length = 64;
283#else
284        s->d1->bitmap.length = sizeof(s->d1->bitmap.map) * 8;
285#endif
286        pq_64bit_init(&(s->d1->bitmap.map));
287        pq_64bit_init(&(s->d1->bitmap.max_seq_num));
288
289        s->d1->next_bitmap.length = s->d1->bitmap.length;
290        pq_64bit_init(&(s->d1->next_bitmap.map));
291        pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
292    }
293
294    ssl3_clear(s);
295    if (s->options & SSL_OP_CISCO_ANYCONNECT)
296        s->version = DTLS1_BAD_VER;
297    else
298        s->version = DTLS1_VERSION;
299}
300
301long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
302{
303    int ret = 0;
304
305    switch (cmd) {
306    case DTLS_CTRL_GET_TIMEOUT:
307        if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
308            ret = 1;
309        }
310        break;
311    case DTLS_CTRL_HANDLE_TIMEOUT:
312        ret = dtls1_handle_timeout(s);
313        break;
314    case DTLS_CTRL_LISTEN:
315        ret = dtls1_listen(s, parg);
316        break;
317    case SSL_CTRL_CHECK_PROTO_VERSION:
318        /*
319         * For library-internal use; checks that the current protocol is the
320         * highest enabled version (according to s->ctx->method, as version
321         * negotiation may have changed s->method).
322         */
323#if DTLS_MAX_VERSION != DTLS1_VERSION
324# error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
325#endif
326        /*
327         * Just one protocol version is supported so far; fail closed if the
328         * version is not as expected.
329         */
330        return s->version == DTLS_MAX_VERSION;
331
332    default:
333        ret = ssl3_ctrl(s, cmd, larg, parg);
334        break;
335    }
336    return (ret);
337}
338
339/*
340 * As it's impossible to use stream ciphers in "datagram" mode, this
341 * simple filter is designed to disengage them in DTLS. Unfortunately
342 * there is no universal way to identify stream SSL_CIPHER, so we have
343 * to explicitly list their SSL_* codes. Currently RC4 is the only one
344 * available, but if new ones emerge, they will have to be added...
345 */
346SSL_CIPHER *dtls1_get_cipher(unsigned int u)
347{
348    SSL_CIPHER *ciph = ssl3_get_cipher(u);
349
350    if (ciph != NULL) {
351        if ((ciph->algorithms & SSL_ENC_MASK) == SSL_RC4)
352            return NULL;
353    }
354
355    return ciph;
356}
357
358void dtls1_start_timer(SSL *s)
359{
360    /* If timer is not set, initialize duration with 1 second */
361    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
362        s->d1->timeout_duration = 1;
363    }
364
365    /* Set timeout to current time */
366    get_current_time(&(s->d1->next_timeout));
367
368    /* Add duration to current time */
369    s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
370    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
371             &(s->d1->next_timeout));
372}
373
374struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
375{
376    struct timeval timenow;
377
378    /* If no timeout is set, just return NULL */
379    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
380        return NULL;
381    }
382
383    /* Get current time */
384    get_current_time(&timenow);
385
386    /* If timer already expired, set remaining time to 0 */
387    if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
388        (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
389         s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
390        memset(timeleft, 0, sizeof(struct timeval));
391        return timeleft;
392    }
393
394    /* Calculate time left until timer expires */
395    memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
396    timeleft->tv_sec -= timenow.tv_sec;
397    timeleft->tv_usec -= timenow.tv_usec;
398    if (timeleft->tv_usec < 0) {
399        timeleft->tv_sec--;
400        timeleft->tv_usec += 1000000;
401    }
402
403    /*
404     * If remaining time is less than 15 ms, set it to 0 to prevent issues
405     * because of small devergences with socket timeouts.
406     */
407    if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
408        memset(timeleft, 0, sizeof(struct timeval));
409    }
410
411    return timeleft;
412}
413
414int dtls1_is_timer_expired(SSL *s)
415{
416    struct timeval timeleft;
417
418    /* Get time left until timeout, return false if no timer running */
419    if (dtls1_get_timeout(s, &timeleft) == NULL) {
420        return 0;
421    }
422
423    /* Return false if timer is not expired yet */
424    if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
425        return 0;
426    }
427
428    /* Timer expired, so return true */
429    return 1;
430}
431
432void dtls1_double_timeout(SSL *s)
433{
434    s->d1->timeout_duration *= 2;
435    if (s->d1->timeout_duration > 60)
436        s->d1->timeout_duration = 60;
437    dtls1_start_timer(s);
438}
439
440void dtls1_stop_timer(SSL *s)
441{
442    /* Reset everything */
443    memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
444    memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
445    s->d1->timeout_duration = 1;
446    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
447             &(s->d1->next_timeout));
448    /* Clear retransmission buffer */
449    dtls1_clear_sent_buffer(s);
450}
451
452int dtls1_check_timeout_num(SSL *s)
453{
454    s->d1->timeout.num_alerts++;
455
456    /* Reduce MTU after 2 unsuccessful retransmissions */
457    if (s->d1->timeout.num_alerts > 2) {
458        s->d1->mtu =
459            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
460                     NULL);
461    }
462
463    if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
464        /* fail the connection, enough alerts have been sent */
465        SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
466        return -1;
467    }
468
469    return 0;
470}
471
472int dtls1_handle_timeout(SSL *s)
473{
474    /* if no timer is expired, don't do anything */
475    if (!dtls1_is_timer_expired(s)) {
476        return 0;
477    }
478
479    dtls1_double_timeout(s);
480
481    if (dtls1_check_timeout_num(s) < 0)
482        return -1;
483
484    s->d1->timeout.read_timeouts++;
485    if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
486        s->d1->timeout.read_timeouts = 1;
487    }
488
489    dtls1_start_timer(s);
490    return dtls1_retransmit_buffered_messages(s);
491}
492
493static void get_current_time(struct timeval *t)
494{
495#ifdef OPENSSL_SYS_WIN32
496    struct _timeb tb;
497    _ftime(&tb);
498    t->tv_sec = (long)tb.time;
499    t->tv_usec = (long)tb.millitm * 1000;
500#elif defined(OPENSSL_SYS_VMS)
501    struct timeb tb;
502    ftime(&tb);
503    t->tv_sec = (long)tb.time;
504    t->tv_usec = (long)tb.millitm * 1000;
505#else
506    gettimeofday(t, NULL);
507#endif
508}
509
510int dtls1_listen(SSL *s, struct sockaddr *client)
511{
512    int ret;
513
514    /* Ensure there is no state left over from a previous invocation */
515    SSL_clear(s);
516
517    SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
518    s->d1->listen = 1;
519
520    ret = SSL_accept(s);
521    if (ret <= 0)
522        return ret;
523
524    (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
525    return 1;
526}
527