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			972 lines
		
	
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			972 lines
		
	
	
	
		
			30 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Copyright 2005-2021 The OpenSSL Project Authors. All Rights Reserved.
 | |
|  *
 | |
|  * Licensed under the OpenSSL license (the "License").  You may not use
 | |
|  * this file except in compliance with the License.  You can obtain a copy
 | |
|  * in the file LICENSE in the source distribution or at
 | |
|  * https://www.openssl.org/source/license.html
 | |
|  */
 | |
| 
 | |
| #include "e_os.h"
 | |
| #include <stdio.h>
 | |
| #include <openssl/objects.h>
 | |
| #include <openssl/rand.h>
 | |
| #include "ssl_local.h"
 | |
| 
 | |
| static void get_current_time(struct timeval *t);
 | |
| static int dtls1_handshake_write(SSL *s);
 | |
| static size_t dtls1_link_min_mtu(void);
 | |
| 
 | |
| /* XDTLS:  figure out the right values */
 | |
| static const size_t g_probable_mtu[] = { 1500, 512, 256 };
 | |
| 
 | |
| const SSL3_ENC_METHOD DTLSv1_enc_data = {
 | |
|     tls1_enc,
 | |
|     tls1_mac,
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|     tls1_setup_key_block,
 | |
|     tls1_generate_master_secret,
 | |
|     tls1_change_cipher_state,
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|     tls1_final_finish_mac,
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|     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
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|     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
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|     tls1_alert_code,
 | |
|     tls1_export_keying_material,
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|     SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
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|     dtls1_set_handshake_header,
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|     dtls1_close_construct_packet,
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|     dtls1_handshake_write
 | |
| };
 | |
| 
 | |
| const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
 | |
|     tls1_enc,
 | |
|     tls1_mac,
 | |
|     tls1_setup_key_block,
 | |
|     tls1_generate_master_secret,
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|     tls1_change_cipher_state,
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|     tls1_final_finish_mac,
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|     TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
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|     TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
 | |
|     tls1_alert_code,
 | |
|     tls1_export_keying_material,
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|     SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
 | |
|         | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
 | |
|     dtls1_set_handshake_header,
 | |
|     dtls1_close_construct_packet,
 | |
|     dtls1_handshake_write
 | |
| };
 | |
| 
 | |
| long dtls1_default_timeout(void)
 | |
| {
 | |
|     /*
 | |
|      * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
 | |
|      * http, the cache would over fill
 | |
|      */
 | |
|     return (60 * 60 * 2);
 | |
| }
 | |
| 
 | |
| int dtls1_new(SSL *s)
 | |
| {
 | |
|     DTLS1_STATE *d1;
 | |
| 
 | |
|     if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     if (!ssl3_new(s))
 | |
|         return 0;
 | |
|     if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
 | |
|         ssl3_free(s);
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|         return 0;
 | |
|     }
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| 
 | |
|     d1->buffered_messages = pqueue_new();
 | |
|     d1->sent_messages = pqueue_new();
 | |
| 
 | |
|     if (s->server) {
 | |
|         d1->cookie_len = sizeof(s->d1->cookie);
 | |
|     }
 | |
| 
 | |
|     d1->link_mtu = 0;
 | |
|     d1->mtu = 0;
 | |
| 
 | |
|     if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
 | |
|         pqueue_free(d1->buffered_messages);
 | |
|         pqueue_free(d1->sent_messages);
 | |
|         OPENSSL_free(d1);
 | |
|         ssl3_free(s);
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     s->d1 = d1;
 | |
| 
 | |
|     if (!s->method->ssl_clear(s))
 | |
|         return 0;
 | |
| 
 | |
|     return 1;
 | |
| }
 | |
| 
 | |
| static void dtls1_clear_queues(SSL *s)
 | |
| {
 | |
|     dtls1_clear_received_buffer(s);
 | |
|     dtls1_clear_sent_buffer(s);
 | |
| }
 | |
| 
 | |
| void dtls1_clear_received_buffer(SSL *s)
 | |
| {
 | |
|     pitem *item = NULL;
 | |
|     hm_fragment *frag = NULL;
 | |
| 
 | |
|     while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
 | |
|         frag = (hm_fragment *)item->data;
 | |
|         dtls1_hm_fragment_free(frag);
 | |
|         pitem_free(item);
 | |
|     }
 | |
| }
 | |
| 
 | |
| void dtls1_clear_sent_buffer(SSL *s)
 | |
| {
 | |
|     pitem *item = NULL;
 | |
|     hm_fragment *frag = NULL;
 | |
| 
 | |
|     while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
 | |
|         frag = (hm_fragment *)item->data;
 | |
|         dtls1_hm_fragment_free(frag);
 | |
|         pitem_free(item);
 | |
|     }
 | |
| }
 | |
| 
 | |
| 
 | |
| void dtls1_free(SSL *s)
 | |
| {
 | |
|     DTLS_RECORD_LAYER_free(&s->rlayer);
 | |
| 
 | |
|     ssl3_free(s);
 | |
| 
 | |
|     if (s->d1 != NULL) {
 | |
|         dtls1_clear_queues(s);
 | |
|         pqueue_free(s->d1->buffered_messages);
 | |
|         pqueue_free(s->d1->sent_messages);
 | |
|     }
 | |
| 
 | |
|     OPENSSL_free(s->d1);
 | |
|     s->d1 = NULL;
 | |
| }
 | |
| 
 | |
| int dtls1_clear(SSL *s)
 | |
| {
 | |
|     pqueue *buffered_messages;
 | |
|     pqueue *sent_messages;
 | |
|     size_t mtu;
 | |
|     size_t link_mtu;
 | |
| 
 | |
|     DTLS_RECORD_LAYER_clear(&s->rlayer);
 | |
| 
 | |
|     if (s->d1) {
 | |
|         DTLS_timer_cb timer_cb = s->d1->timer_cb;
 | |
| 
 | |
|         buffered_messages = s->d1->buffered_messages;
 | |
|         sent_messages = s->d1->sent_messages;
 | |
|         mtu = s->d1->mtu;
 | |
|         link_mtu = s->d1->link_mtu;
 | |
| 
 | |
|         dtls1_clear_queues(s);
 | |
| 
 | |
|         memset(s->d1, 0, sizeof(*s->d1));
 | |
| 
 | |
|         /* Restore the timer callback from previous state */
 | |
|         s->d1->timer_cb = timer_cb;
 | |
| 
 | |
|         if (s->server) {
 | |
|             s->d1->cookie_len = sizeof(s->d1->cookie);
 | |
|         }
 | |
| 
 | |
|         if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
 | |
|             s->d1->mtu = mtu;
 | |
|             s->d1->link_mtu = link_mtu;
 | |
|         }
 | |
| 
 | |
|         s->d1->buffered_messages = buffered_messages;
 | |
|         s->d1->sent_messages = sent_messages;
 | |
|     }
 | |
| 
 | |
|     if (!ssl3_clear(s))
 | |
|         return 0;
 | |
| 
 | |
|     if (s->method->version == DTLS_ANY_VERSION)
 | |
|         s->version = DTLS_MAX_VERSION;
 | |
| #ifndef OPENSSL_NO_DTLS1_METHOD
 | |
|     else if (s->options & SSL_OP_CISCO_ANYCONNECT)
 | |
|         s->client_version = s->version = DTLS1_BAD_VER;
 | |
| #endif
 | |
|     else
 | |
|         s->version = s->method->version;
 | |
| 
 | |
|     return 1;
 | |
| }
 | |
| 
 | |
| long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
 | |
| {
 | |
|     int ret = 0;
 | |
| 
 | |
|     switch (cmd) {
 | |
|     case DTLS_CTRL_GET_TIMEOUT:
 | |
|         if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
 | |
|             ret = 1;
 | |
|         }
 | |
|         break;
 | |
|     case DTLS_CTRL_HANDLE_TIMEOUT:
 | |
|         ret = dtls1_handle_timeout(s);
 | |
|         break;
 | |
|     case DTLS_CTRL_SET_LINK_MTU:
 | |
|         if (larg < (long)dtls1_link_min_mtu())
 | |
|             return 0;
 | |
|         s->d1->link_mtu = larg;
 | |
|         return 1;
 | |
|     case DTLS_CTRL_GET_LINK_MIN_MTU:
 | |
|         return (long)dtls1_link_min_mtu();
 | |
|     case SSL_CTRL_SET_MTU:
 | |
|         /*
 | |
|          *  We may not have a BIO set yet so can't call dtls1_min_mtu()
 | |
|          *  We'll have to make do with dtls1_link_min_mtu() and max overhead
 | |
|          */
 | |
|         if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
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|             return 0;
 | |
|         s->d1->mtu = larg;
 | |
|         return larg;
 | |
|     default:
 | |
|         ret = ssl3_ctrl(s, cmd, larg, parg);
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|         break;
 | |
|     }
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| void dtls1_start_timer(SSL *s)
 | |
| {
 | |
|     unsigned int sec, usec;
 | |
| 
 | |
| #ifndef OPENSSL_NO_SCTP
 | |
|     /* Disable timer for SCTP */
 | |
|     if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
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|         memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
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|         return;
 | |
|     }
 | |
| #endif
 | |
| 
 | |
|     /*
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|      * If timer is not set, initialize duration with 1 second or
 | |
|      * a user-specified value if the timer callback is installed.
 | |
|      */
 | |
|     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 | |
| 
 | |
|         if (s->d1->timer_cb != NULL)
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|             s->d1->timeout_duration_us = s->d1->timer_cb(s, 0);
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|         else
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|             s->d1->timeout_duration_us = 1000000;
 | |
|     }
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| 
 | |
|     /* Set timeout to current time */
 | |
|     get_current_time(&(s->d1->next_timeout));
 | |
| 
 | |
|     /* Add duration to current time */
 | |
| 
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|     sec  = s->d1->timeout_duration_us / 1000000;
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|     usec = s->d1->timeout_duration_us - (sec * 1000000);
 | |
| 
 | |
|     s->d1->next_timeout.tv_sec  += sec;
 | |
|     s->d1->next_timeout.tv_usec += usec;
 | |
| 
 | |
|     if (s->d1->next_timeout.tv_usec >= 1000000) {
 | |
|         s->d1->next_timeout.tv_sec++;
 | |
|         s->d1->next_timeout.tv_usec -= 1000000;
 | |
|     }
 | |
| 
 | |
|     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
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|              &(s->d1->next_timeout));
 | |
| }
 | |
| 
 | |
| struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
 | |
| {
 | |
|     struct timeval timenow;
 | |
| 
 | |
|     /* If no timeout is set, just return NULL */
 | |
|     if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
 | |
|         return NULL;
 | |
|     }
 | |
| 
 | |
|     /* Get current time */
 | |
|     get_current_time(&timenow);
 | |
| 
 | |
|     /* If timer already expired, set remaining time to 0 */
 | |
|     if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
 | |
|         (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
 | |
|          s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
 | |
|         memset(timeleft, 0, sizeof(*timeleft));
 | |
|         return timeleft;
 | |
|     }
 | |
| 
 | |
|     /* Calculate time left until timer expires */
 | |
|     memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
 | |
|     timeleft->tv_sec -= timenow.tv_sec;
 | |
|     timeleft->tv_usec -= timenow.tv_usec;
 | |
|     if (timeleft->tv_usec < 0) {
 | |
|         timeleft->tv_sec--;
 | |
|         timeleft->tv_usec += 1000000;
 | |
|     }
 | |
| 
 | |
|     /*
 | |
|      * If remaining time is less than 15 ms, set it to 0 to prevent issues
 | |
|      * because of small divergences with socket timeouts.
 | |
|      */
 | |
|     if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
 | |
|         memset(timeleft, 0, sizeof(*timeleft));
 | |
|     }
 | |
| 
 | |
|     return timeleft;
 | |
| }
 | |
| 
 | |
| int dtls1_is_timer_expired(SSL *s)
 | |
| {
 | |
|     struct timeval timeleft;
 | |
| 
 | |
|     /* Get time left until timeout, return false if no timer running */
 | |
|     if (dtls1_get_timeout(s, &timeleft) == NULL) {
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     /* Return false if timer is not expired yet */
 | |
|     if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     /* Timer expired, so return true */
 | |
|     return 1;
 | |
| }
 | |
| 
 | |
| static void dtls1_double_timeout(SSL *s)
 | |
| {
 | |
|     s->d1->timeout_duration_us *= 2;
 | |
|     if (s->d1->timeout_duration_us > 60000000)
 | |
|         s->d1->timeout_duration_us = 60000000;
 | |
| }
 | |
| 
 | |
| void dtls1_stop_timer(SSL *s)
 | |
| {
 | |
|     /* Reset everything */
 | |
|     memset(&s->d1->timeout, 0, sizeof(s->d1->timeout));
 | |
|     memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
 | |
|     s->d1->timeout_duration_us = 1000000;
 | |
|     BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
 | |
|              &(s->d1->next_timeout));
 | |
|     /* Clear retransmission buffer */
 | |
|     dtls1_clear_sent_buffer(s);
 | |
| }
 | |
| 
 | |
| int dtls1_check_timeout_num(SSL *s)
 | |
| {
 | |
|     size_t mtu;
 | |
| 
 | |
|     s->d1->timeout.num_alerts++;
 | |
| 
 | |
|     /* Reduce MTU after 2 unsuccessful retransmissions */
 | |
|     if (s->d1->timeout.num_alerts > 2
 | |
|         && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
 | |
|         mtu =
 | |
|             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
 | |
|         if (mtu < s->d1->mtu)
 | |
|             s->d1->mtu = mtu;
 | |
|     }
 | |
| 
 | |
|     if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
 | |
|         /* fail the connection, enough alerts have been sent */
 | |
|         SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS1_CHECK_TIMEOUT_NUM,
 | |
|                  SSL_R_READ_TIMEOUT_EXPIRED);
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| int dtls1_handle_timeout(SSL *s)
 | |
| {
 | |
|     /* if no timer is expired, don't do anything */
 | |
|     if (!dtls1_is_timer_expired(s)) {
 | |
|         return 0;
 | |
|     }
 | |
| 
 | |
|     if (s->d1->timer_cb != NULL)
 | |
|         s->d1->timeout_duration_us = s->d1->timer_cb(s, s->d1->timeout_duration_us);
 | |
|     else
 | |
|         dtls1_double_timeout(s);
 | |
| 
 | |
|     if (dtls1_check_timeout_num(s) < 0) {
 | |
|         /* SSLfatal() already called */
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     s->d1->timeout.read_timeouts++;
 | |
|     if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
 | |
|         s->d1->timeout.read_timeouts = 1;
 | |
|     }
 | |
| 
 | |
|     dtls1_start_timer(s);
 | |
|     /* Calls SSLfatal() if required */
 | |
|     return dtls1_retransmit_buffered_messages(s);
 | |
| }
 | |
| 
 | |
| static void get_current_time(struct timeval *t)
 | |
| {
 | |
| #if defined(_WIN32)
 | |
|     SYSTEMTIME st;
 | |
|     union {
 | |
|         unsigned __int64 ul;
 | |
|         FILETIME ft;
 | |
|     } now;
 | |
| 
 | |
|     GetSystemTime(&st);
 | |
|     SystemTimeToFileTime(&st, &now.ft);
 | |
|     /* re-bias to 1/1/1970 */
 | |
| # ifdef  __MINGW32__
 | |
|     now.ul -= 116444736000000000ULL;
 | |
| # else
 | |
|     /* *INDENT-OFF* */
 | |
|     now.ul -= 116444736000000000UI64;
 | |
|     /* *INDENT-ON* */
 | |
| # endif
 | |
|     t->tv_sec = (long)(now.ul / 10000000);
 | |
|     t->tv_usec = ((int)(now.ul % 10000000)) / 10;
 | |
| #else
 | |
|     gettimeofday(t, NULL);
 | |
| #endif
 | |
| }
 | |
| 
 | |
| #define LISTEN_SUCCESS              2
 | |
| #define LISTEN_SEND_VERIFY_REQUEST  1
 | |
| 
 | |
| #ifndef OPENSSL_NO_SOCK
 | |
| int DTLSv1_listen(SSL *s, BIO_ADDR *client)
 | |
| {
 | |
|     int next, n, ret = 0;
 | |
|     unsigned char cookie[DTLS1_COOKIE_LENGTH];
 | |
|     unsigned char seq[SEQ_NUM_SIZE];
 | |
|     const unsigned char *data;
 | |
|     unsigned char *buf, *wbuf;
 | |
|     size_t fragoff, fraglen, msglen, reclen, align = 0;
 | |
|     unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
 | |
|     BIO *rbio, *wbio;
 | |
|     BIO_ADDR *tmpclient = NULL;
 | |
|     PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
 | |
| 
 | |
|     if (s->handshake_func == NULL) {
 | |
|         /* Not properly initialized yet */
 | |
|         SSL_set_accept_state(s);
 | |
|     }
 | |
| 
 | |
|     /* Ensure there is no state left over from a previous invocation */
 | |
|     if (!SSL_clear(s))
 | |
|         return -1;
 | |
| 
 | |
|     ERR_clear_error();
 | |
| 
 | |
|     rbio = SSL_get_rbio(s);
 | |
|     wbio = SSL_get_wbio(s);
 | |
| 
 | |
|     if (!rbio || !wbio) {
 | |
|         SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     /*
 | |
|      * Note: This check deliberately excludes DTLS1_BAD_VER because that version
 | |
|      * requires the MAC to be calculated *including* the first ClientHello
 | |
|      * (without the cookie). Since DTLSv1_listen is stateless that cannot be
 | |
|      * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
 | |
|      * SSL_accept)
 | |
|      */
 | |
|     if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
 | |
|         SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
 | |
|         return -1;
 | |
|     }
 | |
| 
 | |
|     if (!ssl3_setup_buffers(s)) {
 | |
|         /* SSLerr already called */
 | |
|         return -1;
 | |
|     }
 | |
|     buf = RECORD_LAYER_get_rbuf(&s->rlayer)->buf;
 | |
|     wbuf = RECORD_LAYER_get_wbuf(&s->rlayer)[0].buf;
 | |
| #if defined(SSL3_ALIGN_PAYLOAD)
 | |
| # if SSL3_ALIGN_PAYLOAD != 0
 | |
|     /*
 | |
|      * Using SSL3_RT_HEADER_LENGTH here instead of DTLS1_RT_HEADER_LENGTH for
 | |
|      * consistency with ssl3_read_n. In practice it should make no difference
 | |
|      * for sensible values of SSL3_ALIGN_PAYLOAD because the difference between
 | |
|      * SSL3_RT_HEADER_LENGTH and DTLS1_RT_HEADER_LENGTH is exactly 8
 | |
|      */
 | |
|     align = (size_t)buf + SSL3_RT_HEADER_LENGTH;
 | |
|     align = SSL3_ALIGN_PAYLOAD - 1 - ((align - 1) % SSL3_ALIGN_PAYLOAD);
 | |
| # endif
 | |
| #endif
 | |
|     buf += align;
 | |
| 
 | |
|     do {
 | |
|         /* Get a packet */
 | |
| 
 | |
|         clear_sys_error();
 | |
|         n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH
 | |
|                                 + DTLS1_RT_HEADER_LENGTH);
 | |
|         if (n <= 0) {
 | |
|             if (BIO_should_retry(rbio)) {
 | |
|                 /* Non-blocking IO */
 | |
|                 goto end;
 | |
|             }
 | |
|             return -1;
 | |
|         }
 | |
| 
 | |
|         if (!PACKET_buf_init(&pkt, buf, n)) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
 | |
|             return -1;
 | |
|         }
 | |
| 
 | |
|         /*
 | |
|          * Parse the received record. If there are any problems with it we just
 | |
|          * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
 | |
|          * resilient in the face of invalid records (e.g., invalid formatting,
 | |
|          * length, MAC, etc.).  In general, invalid records SHOULD be silently
 | |
|          * discarded, thus preserving the association; however, an error MAY be
 | |
|          * logged for diagnostic purposes."
 | |
|          */
 | |
| 
 | |
|         /* this packet contained a partial record, dump it */
 | |
|         if (n < DTLS1_RT_HEADER_LENGTH) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (s->msg_callback)
 | |
|             s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
 | |
|                             DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
 | |
| 
 | |
|         /* Get the record header */
 | |
|         if (!PACKET_get_1(&pkt, &rectype)
 | |
|             || !PACKET_get_1(&pkt, &versmajor)) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (rectype != SSL3_RT_HANDSHAKE) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /*
 | |
|          * Check record version number. We only check that the major version is
 | |
|          * the same.
 | |
|          */
 | |
|         if (versmajor != DTLS1_VERSION_MAJOR) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (!PACKET_forward(&pkt, 1)
 | |
|             /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
 | |
|             || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
 | |
|             || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
 | |
|             goto end;
 | |
|         }
 | |
|         reclen = PACKET_remaining(&msgpkt);
 | |
|         /*
 | |
|          * We allow data remaining at the end of the packet because there could
 | |
|          * be a second record (but we ignore it)
 | |
|          */
 | |
| 
 | |
|         /* This is an initial ClientHello so the epoch has to be 0 */
 | |
|         if (seq[0] != 0 || seq[1] != 0) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /* Get a pointer to the raw message for the later callback */
 | |
|         data = PACKET_data(&msgpkt);
 | |
| 
 | |
|         /* Finished processing the record header, now process the message */
 | |
|         if (!PACKET_get_1(&msgpkt, &msgtype)
 | |
|             || !PACKET_get_net_3_len(&msgpkt, &msglen)
 | |
|             || !PACKET_get_net_2(&msgpkt, &msgseq)
 | |
|             || !PACKET_get_net_3_len(&msgpkt, &fragoff)
 | |
|             || !PACKET_get_net_3_len(&msgpkt, &fraglen)
 | |
|             || !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
 | |
|             || PACKET_remaining(&msgpkt) != 0) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (msgtype != SSL3_MT_CLIENT_HELLO) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /* Message sequence number can only be 0 or 1 */
 | |
|         if (msgseq > 2) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /*
 | |
|          * We don't support fragment reassembly for ClientHellos whilst
 | |
|          * listening because that would require server side state (which is
 | |
|          * against the whole point of the ClientHello/HelloVerifyRequest
 | |
|          * mechanism). Instead we only look at the first ClientHello fragment
 | |
|          * and require that the cookie must be contained within it.
 | |
|          */
 | |
|         if (fragoff != 0 || fraglen > msglen) {
 | |
|             /* Non initial ClientHello fragment (or bad fragment) */
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (s->msg_callback)
 | |
|             s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
 | |
|                             fraglen + DTLS1_HM_HEADER_LENGTH, s,
 | |
|                             s->msg_callback_arg);
 | |
| 
 | |
|         if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /*
 | |
|          * Verify client version is supported
 | |
|          */
 | |
|         if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
 | |
|             s->method->version != DTLS_ANY_VERSION) {
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
 | |
|             || !PACKET_get_length_prefixed_1(&msgpayload, &session)
 | |
|             || !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
 | |
|             /*
 | |
|              * Could be malformed or the cookie does not fit within the initial
 | |
|              * ClientHello fragment. Either way we can't handle it.
 | |
|              */
 | |
|             SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
 | |
|             goto end;
 | |
|         }
 | |
| 
 | |
|         /*
 | |
|          * Check if we have a cookie or not. If not we need to send a
 | |
|          * HelloVerifyRequest.
 | |
|          */
 | |
|         if (PACKET_remaining(&cookiepkt) == 0) {
 | |
|             next = LISTEN_SEND_VERIFY_REQUEST;
 | |
|         } else {
 | |
|             /*
 | |
|              * We have a cookie, so lets check it.
 | |
|              */
 | |
|             if (s->ctx->app_verify_cookie_cb == NULL) {
 | |
|                 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
 | |
|                 /* This is fatal */
 | |
|                 return -1;
 | |
|             }
 | |
|             if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
 | |
|                     (unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
 | |
|                 /*
 | |
|                  * We treat invalid cookies in the same was as no cookie as
 | |
|                  * per RFC6347
 | |
|                  */
 | |
|                 next = LISTEN_SEND_VERIFY_REQUEST;
 | |
|             } else {
 | |
|                 /* Cookie verification succeeded */
 | |
|                 next = LISTEN_SUCCESS;
 | |
|             }
 | |
|         }
 | |
| 
 | |
|         if (next == LISTEN_SEND_VERIFY_REQUEST) {
 | |
|             WPACKET wpkt;
 | |
|             unsigned int version;
 | |
|             size_t wreclen;
 | |
| 
 | |
|             /*
 | |
|              * There was no cookie in the ClientHello so we need to send a
 | |
|              * HelloVerifyRequest. If this fails we do not worry about trying
 | |
|              * to resend, we just drop it.
 | |
|              */
 | |
| 
 | |
|             /* Generate the cookie */
 | |
|             if (s->ctx->app_gen_cookie_cb == NULL ||
 | |
|                 s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
 | |
|                 cookielen > 255) {
 | |
|                 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
 | |
|                 /* This is fatal */
 | |
|                 return -1;
 | |
|             }
 | |
| 
 | |
|             /*
 | |
|              * Special case: for hello verify request, client version 1.0 and we
 | |
|              * haven't decided which version to use yet send back using version
 | |
|              * 1.0 header: otherwise some clients will ignore it.
 | |
|              */
 | |
|             version = (s->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
 | |
|                                                                : s->version;
 | |
| 
 | |
|             /* Construct the record and message headers */
 | |
|             if (!WPACKET_init_static_len(&wpkt,
 | |
|                                          wbuf,
 | |
|                                          ssl_get_max_send_fragment(s)
 | |
|                                          + DTLS1_RT_HEADER_LENGTH,
 | |
|                                          0)
 | |
|                     || !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
 | |
|                     || !WPACKET_put_bytes_u16(&wpkt, version)
 | |
|                        /*
 | |
|                         * Record sequence number is always the same as in the
 | |
|                         * received ClientHello
 | |
|                         */
 | |
|                     || !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
 | |
|                        /* End of record, start sub packet for message */
 | |
|                     || !WPACKET_start_sub_packet_u16(&wpkt)
 | |
|                        /* Message type */
 | |
|                     || !WPACKET_put_bytes_u8(&wpkt,
 | |
|                                              DTLS1_MT_HELLO_VERIFY_REQUEST)
 | |
|                        /*
 | |
|                         * Message length - doesn't follow normal TLS convention:
 | |
|                         * the length isn't the last thing in the message header.
 | |
|                         * We'll need to fill this in later when we know the
 | |
|                         * length. Set it to zero for now
 | |
|                         */
 | |
|                     || !WPACKET_put_bytes_u24(&wpkt, 0)
 | |
|                        /*
 | |
|                         * Message sequence number is always 0 for a
 | |
|                         * HelloVerifyRequest
 | |
|                         */
 | |
|                     || !WPACKET_put_bytes_u16(&wpkt, 0)
 | |
|                        /*
 | |
|                         * We never fragment a HelloVerifyRequest, so fragment
 | |
|                         * offset is 0
 | |
|                         */
 | |
|                     || !WPACKET_put_bytes_u24(&wpkt, 0)
 | |
|                        /*
 | |
|                         * Fragment length is the same as message length, but
 | |
|                         * this *is* the last thing in the message header so we
 | |
|                         * can just start a sub-packet. No need to come back
 | |
|                         * later for this one.
 | |
|                         */
 | |
|                     || !WPACKET_start_sub_packet_u24(&wpkt)
 | |
|                        /* Create the actual HelloVerifyRequest body */
 | |
|                     || !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
 | |
|                        /* Close message body */
 | |
|                     || !WPACKET_close(&wpkt)
 | |
|                        /* Close record body */
 | |
|                     || !WPACKET_close(&wpkt)
 | |
|                     || !WPACKET_get_total_written(&wpkt, &wreclen)
 | |
|                     || !WPACKET_finish(&wpkt)) {
 | |
|                 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
 | |
|                 WPACKET_cleanup(&wpkt);
 | |
|                 /* This is fatal */
 | |
|                 return -1;
 | |
|             }
 | |
| 
 | |
|             /*
 | |
|              * Fix up the message len in the message header. Its the same as the
 | |
|              * fragment len which has been filled in by WPACKET, so just copy
 | |
|              * that. Destination for the message len is after the record header
 | |
|              * plus one byte for the message content type. The source is the
 | |
|              * last 3 bytes of the message header
 | |
|              */
 | |
|             memcpy(&wbuf[DTLS1_RT_HEADER_LENGTH + 1],
 | |
|                    &wbuf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
 | |
|                    3);
 | |
| 
 | |
|             if (s->msg_callback)
 | |
|                 s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
 | |
|                                 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
 | |
| 
 | |
|             if ((tmpclient = BIO_ADDR_new()) == NULL) {
 | |
|                 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
 | |
|                 goto end;
 | |
|             }
 | |
| 
 | |
|             /*
 | |
|              * This is unnecessary if rbio and wbio are one and the same - but
 | |
|              * maybe they're not. We ignore errors here - some BIOs do not
 | |
|              * support this.
 | |
|              */
 | |
|             if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
 | |
|                 (void)BIO_dgram_set_peer(wbio, tmpclient);
 | |
|             }
 | |
|             BIO_ADDR_free(tmpclient);
 | |
|             tmpclient = NULL;
 | |
| 
 | |
|             /* TODO(size_t): convert this call */
 | |
|             if (BIO_write(wbio, wbuf, wreclen) < (int)wreclen) {
 | |
|                 if (BIO_should_retry(wbio)) {
 | |
|                     /*
 | |
|                      * Non-blocking IO...but we're stateless, so we're just
 | |
|                      * going to drop this packet.
 | |
|                      */
 | |
|                     goto end;
 | |
|                 }
 | |
|                 return -1;
 | |
|             }
 | |
| 
 | |
|             if (BIO_flush(wbio) <= 0) {
 | |
|                 if (BIO_should_retry(wbio)) {
 | |
|                     /*
 | |
|                      * Non-blocking IO...but we're stateless, so we're just
 | |
|                      * going to drop this packet.
 | |
|                      */
 | |
|                     goto end;
 | |
|                 }
 | |
|                 return -1;
 | |
|             }
 | |
|         }
 | |
|     } while (next != LISTEN_SUCCESS);
 | |
| 
 | |
|     /*
 | |
|      * Set expected sequence numbers to continue the handshake.
 | |
|      */
 | |
|     s->d1->handshake_read_seq = 1;
 | |
|     s->d1->handshake_write_seq = 1;
 | |
|     s->d1->next_handshake_write_seq = 1;
 | |
|     DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);
 | |
| 
 | |
|     /*
 | |
|      * We are doing cookie exchange, so make sure we set that option in the
 | |
|      * SSL object
 | |
|      */
 | |
|     SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
 | |
| 
 | |
|     /*
 | |
|      * Tell the state machine that we've done the initial hello verify
 | |
|      * exchange
 | |
|      */
 | |
|     ossl_statem_set_hello_verify_done(s);
 | |
| 
 | |
|     /*
 | |
|      * Some BIOs may not support this. If we fail we clear the client address
 | |
|      */
 | |
|     if (BIO_dgram_get_peer(rbio, client) <= 0)
 | |
|         BIO_ADDR_clear(client);
 | |
| 
 | |
|     /* Buffer the record in the processed_rcds queue */
 | |
|     if (!dtls_buffer_listen_record(s, reclen, seq, align))
 | |
|         return -1;
 | |
| 
 | |
|     ret = 1;
 | |
|  end:
 | |
|     BIO_ADDR_free(tmpclient);
 | |
|     return ret;
 | |
| }
 | |
| #endif
 | |
| 
 | |
| static int dtls1_handshake_write(SSL *s)
 | |
| {
 | |
|     return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 | |
| }
 | |
| 
 | |
| int dtls1_shutdown(SSL *s)
 | |
| {
 | |
|     int ret;
 | |
| #ifndef OPENSSL_NO_SCTP
 | |
|     BIO *wbio;
 | |
| 
 | |
|     wbio = SSL_get_wbio(s);
 | |
|     if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
 | |
|         !(s->shutdown & SSL_SENT_SHUTDOWN)) {
 | |
|         ret = BIO_dgram_sctp_wait_for_dry(wbio);
 | |
|         if (ret < 0)
 | |
|             return -1;
 | |
| 
 | |
|         if (ret == 0)
 | |
|             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
 | |
|                      NULL);
 | |
|     }
 | |
| #endif
 | |
|     ret = ssl3_shutdown(s);
 | |
| #ifndef OPENSSL_NO_SCTP
 | |
|     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
 | |
| #endif
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| int dtls1_query_mtu(SSL *s)
 | |
| {
 | |
|     if (s->d1->link_mtu) {
 | |
|         s->d1->mtu =
 | |
|             s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
 | |
|         s->d1->link_mtu = 0;
 | |
|     }
 | |
| 
 | |
|     /* AHA!  Figure out the MTU, and stick to the right size */
 | |
|     if (s->d1->mtu < dtls1_min_mtu(s)) {
 | |
|         if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
 | |
|             s->d1->mtu =
 | |
|                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 | |
| 
 | |
|             /*
 | |
|              * I've seen the kernel return bogus numbers when it doesn't know
 | |
|              * (initial write), so just make sure we have a reasonable number
 | |
|              */
 | |
|             if (s->d1->mtu < dtls1_min_mtu(s)) {
 | |
|                 /* Set to min mtu */
 | |
|                 s->d1->mtu = dtls1_min_mtu(s);
 | |
|                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 | |
|                          (long)s->d1->mtu, NULL);
 | |
|             }
 | |
|         } else
 | |
|             return 0;
 | |
|     }
 | |
|     return 1;
 | |
| }
 | |
| 
 | |
| static size_t dtls1_link_min_mtu(void)
 | |
| {
 | |
|     return (g_probable_mtu[(sizeof(g_probable_mtu) /
 | |
|                             sizeof(g_probable_mtu[0])) - 1]);
 | |
| }
 | |
| 
 | |
| size_t dtls1_min_mtu(SSL *s)
 | |
| {
 | |
|     return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
 | |
| }
 | |
| 
 | |
| size_t DTLS_get_data_mtu(const SSL *s)
 | |
| {
 | |
|     size_t mac_overhead, int_overhead, blocksize, ext_overhead;
 | |
|     const SSL_CIPHER *ciph = SSL_get_current_cipher(s);
 | |
|     size_t mtu = s->d1->mtu;
 | |
| 
 | |
|     if (ciph == NULL)
 | |
|         return 0;
 | |
| 
 | |
|     if (!ssl_cipher_get_overhead(ciph, &mac_overhead, &int_overhead,
 | |
|                                  &blocksize, &ext_overhead))
 | |
|         return 0;
 | |
| 
 | |
|     if (SSL_READ_ETM(s))
 | |
|         ext_overhead += mac_overhead;
 | |
|     else
 | |
|         int_overhead += mac_overhead;
 | |
| 
 | |
|     /* Subtract external overhead (e.g. IV/nonce, separate MAC) */
 | |
|     if (ext_overhead + DTLS1_RT_HEADER_LENGTH >= mtu)
 | |
|         return 0;
 | |
|     mtu -= ext_overhead + DTLS1_RT_HEADER_LENGTH;
 | |
| 
 | |
|     /* Round encrypted payload down to cipher block size (for CBC etc.)
 | |
|      * No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
 | |
|     if (blocksize)
 | |
|         mtu -= (mtu % blocksize);
 | |
| 
 | |
|     /* Subtract internal overhead (e.g. CBC padding len byte) */
 | |
|     if (int_overhead >= mtu)
 | |
|         return 0;
 | |
|     mtu -= int_overhead;
 | |
| 
 | |
|     return mtu;
 | |
| }
 | |
| 
 | |
| void DTLS_set_timer_cb(SSL *s, DTLS_timer_cb cb)
 | |
| {
 | |
|     s->d1->timer_cb = cb;
 | |
| }
 |