| /* |
| * DTLS implementation written by Nagendra Modadugu |
| * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. |
| */ |
| /* ==================================================================== |
| * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in |
| * the documentation and/or other materials provided with the |
| * distribution. |
| * |
| * 3. All advertising materials mentioning features or use of this |
| * software must display the following acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" |
| * |
| * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| * endorse or promote products derived from this software without |
| * prior written permission. For written permission, please contact |
| * openssl-core@OpenSSL.org. |
| * |
| * 5. Products derived from this software may not be called "OpenSSL" |
| * nor may "OpenSSL" appear in their names without prior written |
| * permission of the OpenSSL Project. |
| * |
| * 6. Redistributions of any form whatsoever must retain the following |
| * acknowledgment: |
| * "This product includes software developed by the OpenSSL Project |
| * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * ==================================================================== |
| * |
| * This product includes cryptographic software written by Eric Young |
| * (eay@cryptsoft.com). This product includes software written by Tim |
| * Hudson (tjh@cryptsoft.com). */ |
| |
| #include <openssl/ssl.h> |
| |
| #include <assert.h> |
| #include <limits.h> |
| #include <string.h> |
| |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/nid.h> |
| |
| #include "internal.h" |
| |
| #if defined(OPENSSL_WINDOWS) |
| #include <sys/timeb.h> |
| #else |
| #include <sys/socket.h> |
| #include <sys/time.h> |
| #endif |
| |
| |
| /* DTLS1_MTU_TIMEOUTS is the maximum number of timeouts to expire |
| * before starting to decrease the MTU. */ |
| #define DTLS1_MTU_TIMEOUTS 2 |
| |
| /* DTLS1_MAX_TIMEOUTS is the maximum number of timeouts to expire |
| * before failing the DTLS handshake. */ |
| #define DTLS1_MAX_TIMEOUTS 12 |
| |
| static void get_current_time(const SSL *ssl, struct timeval *out_clock); |
| |
| int dtls1_new(SSL *ssl) { |
| DTLS1_STATE *d1; |
| |
| if (!ssl3_new(ssl)) { |
| return 0; |
| } |
| d1 = OPENSSL_malloc(sizeof *d1); |
| if (d1 == NULL) { |
| ssl3_free(ssl); |
| return 0; |
| } |
| memset(d1, 0, sizeof *d1); |
| |
| ssl->d1 = d1; |
| |
| /* Set the version to the highest supported version. |
| * |
| * TODO(davidben): Move this field into |s3|, have it store the normalized |
| * protocol version, and implement this pre-negotiation quirk in |SSL_version| |
| * at the API boundary rather than in internal state. */ |
| ssl->version = DTLS1_2_VERSION; |
| return 1; |
| } |
| |
| void dtls1_free(SSL *ssl) { |
| ssl3_free(ssl); |
| |
| if (ssl == NULL || ssl->d1 == NULL) { |
| return; |
| } |
| |
| dtls_clear_incoming_messages(ssl); |
| dtls_clear_outgoing_messages(ssl); |
| |
| OPENSSL_free(ssl->d1); |
| ssl->d1 = NULL; |
| } |
| |
| int dtls1_supports_cipher(const SSL_CIPHER *cipher) { |
| /* DTLS does not support stream ciphers. The NULL cipher is rejected because |
| * it's not needed. */ |
| return cipher->algorithm_enc != SSL_RC4 && cipher->algorithm_enc != SSL_eNULL; |
| } |
| |
| void DTLSv1_set_initial_timeout_duration(SSL *ssl, unsigned int duration_ms) { |
| ssl->initial_timeout_duration_ms = duration_ms; |
| } |
| |
| void dtls1_start_timer(SSL *ssl) { |
| /* If timer is not set, initialize duration (by default, 1 second) */ |
| if (ssl->d1->next_timeout.tv_sec == 0 && ssl->d1->next_timeout.tv_usec == 0) { |
| ssl->d1->timeout_duration_ms = ssl->initial_timeout_duration_ms; |
| } |
| |
| /* Set timeout to current time */ |
| get_current_time(ssl, &ssl->d1->next_timeout); |
| |
| /* Add duration to current time */ |
| ssl->d1->next_timeout.tv_sec += ssl->d1->timeout_duration_ms / 1000; |
| ssl->d1->next_timeout.tv_usec += (ssl->d1->timeout_duration_ms % 1000) * 1000; |
| if (ssl->d1->next_timeout.tv_usec >= 1000000) { |
| ssl->d1->next_timeout.tv_sec++; |
| ssl->d1->next_timeout.tv_usec -= 1000000; |
| } |
| BIO_ctrl(ssl->rbio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, |
| &ssl->d1->next_timeout); |
| } |
| |
| int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out) { |
| if (!SSL_IS_DTLS(ssl)) { |
| return 0; |
| } |
| |
| /* If no timeout is set, just return NULL */ |
| if (ssl->d1->next_timeout.tv_sec == 0 && ssl->d1->next_timeout.tv_usec == 0) { |
| return 0; |
| } |
| |
| /* Get current time */ |
| struct timeval timenow; |
| get_current_time(ssl, &timenow); |
| |
| /* If timer already expired, set remaining time to 0 */ |
| if (ssl->d1->next_timeout.tv_sec < timenow.tv_sec || |
| (ssl->d1->next_timeout.tv_sec == timenow.tv_sec && |
| ssl->d1->next_timeout.tv_usec <= timenow.tv_usec)) { |
| memset(out, 0, sizeof(struct timeval)); |
| return 1; |
| } |
| |
| /* Calculate time left until timer expires */ |
| memcpy(out, &ssl->d1->next_timeout, sizeof(struct timeval)); |
| out->tv_sec -= timenow.tv_sec; |
| out->tv_usec -= timenow.tv_usec; |
| if (out->tv_usec < 0) { |
| out->tv_sec--; |
| out->tv_usec += 1000000; |
| } |
| |
| /* If remaining time is less than 15 ms, set it to 0 to prevent issues |
| * because of small devergences with socket timeouts. */ |
| if (out->tv_sec == 0 && out->tv_usec < 15000) { |
| memset(out, 0, sizeof(struct timeval)); |
| } |
| |
| return 1; |
| } |
| |
| int dtls1_is_timer_expired(SSL *ssl) { |
| struct timeval timeleft; |
| |
| /* Get time left until timeout, return false if no timer running */ |
| if (!DTLSv1_get_timeout(ssl, &timeleft)) { |
| 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; |
| } |
| |
| void dtls1_double_timeout(SSL *ssl) { |
| ssl->d1->timeout_duration_ms *= 2; |
| if (ssl->d1->timeout_duration_ms > 60000) { |
| ssl->d1->timeout_duration_ms = 60000; |
| } |
| dtls1_start_timer(ssl); |
| } |
| |
| void dtls1_stop_timer(SSL *ssl) { |
| /* Reset everything */ |
| ssl->d1->num_timeouts = 0; |
| memset(&ssl->d1->next_timeout, 0, sizeof(struct timeval)); |
| ssl->d1->timeout_duration_ms = ssl->initial_timeout_duration_ms; |
| BIO_ctrl(ssl->rbio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, |
| &ssl->d1->next_timeout); |
| /* Clear retransmission buffer */ |
| dtls_clear_outgoing_messages(ssl); |
| } |
| |
| int dtls1_check_timeout_num(SSL *ssl) { |
| ssl->d1->num_timeouts++; |
| |
| /* Reduce MTU after 2 unsuccessful retransmissions */ |
| if (ssl->d1->num_timeouts > DTLS1_MTU_TIMEOUTS && |
| !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) { |
| long mtu = BIO_ctrl(ssl->wbio, BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); |
| if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) { |
| ssl->d1->mtu = (unsigned)mtu; |
| } |
| } |
| |
| if (ssl->d1->num_timeouts > DTLS1_MAX_TIMEOUTS) { |
| /* fail the connection, enough alerts have been sent */ |
| OPENSSL_PUT_ERROR(SSL, SSL_R_READ_TIMEOUT_EXPIRED); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| int DTLSv1_handle_timeout(SSL *ssl) { |
| ssl->rwstate = SSL_NOTHING; |
| /* Functions which use SSL_get_error must clear the error queue on entry. */ |
| ERR_clear_error(); |
| |
| if (!SSL_IS_DTLS(ssl)) { |
| return -1; |
| } |
| |
| /* if no timer is expired, don't do anything */ |
| if (!dtls1_is_timer_expired(ssl)) { |
| return 0; |
| } |
| |
| dtls1_double_timeout(ssl); |
| |
| if (dtls1_check_timeout_num(ssl) < 0) { |
| return -1; |
| } |
| |
| dtls1_start_timer(ssl); |
| return dtls1_retransmit_outgoing_messages(ssl); |
| } |
| |
| static void get_current_time(const SSL *ssl, struct timeval *out_clock) { |
| if (ssl->ctx->current_time_cb != NULL) { |
| ssl->ctx->current_time_cb(ssl, out_clock); |
| return; |
| } |
| |
| #if defined(OPENSSL_WINDOWS) |
| struct _timeb time; |
| _ftime(&time); |
| out_clock->tv_sec = time.time; |
| out_clock->tv_usec = time.millitm * 1000; |
| #else |
| gettimeofday(out_clock, NULL); |
| #endif |
| } |
| |
| void dtls1_expect_flight(SSL *ssl) { |
| dtls1_start_timer(ssl); |
| } |
| |
| void dtls1_received_flight(SSL *ssl) { |
| dtls1_stop_timer(ssl); |
| } |