| /* |
| * 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/base.h> |
| |
| #include <limits.h> |
| #include <stdio.h> |
| #include <string.h> |
| |
| #if defined(OPENSSL_WINDOWS) |
| #include <sys/timeb.h> |
| #else |
| #include <sys/socket.h> |
| #include <sys/time.h> |
| #endif |
| |
| #include <openssl/err.h> |
| #include <openssl/mem.h> |
| #include <openssl/obj.h> |
| |
| #include "internal.h" |
| |
| /* 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 *s) { |
| DTLS1_STATE *d1; |
| |
| if (!ssl3_new(s)) { |
| return 0; |
| } |
| d1 = OPENSSL_malloc(sizeof *d1); |
| if (d1 == NULL) { |
| ssl3_free(s); |
| return 0; |
| } |
| memset(d1, 0, sizeof *d1); |
| |
| d1->buffered_messages = pqueue_new(); |
| d1->sent_messages = pqueue_new(); |
| |
| if (!d1->buffered_messages || !d1->sent_messages) { |
| pqueue_free(d1->buffered_messages); |
| pqueue_free(d1->sent_messages); |
| OPENSSL_free(d1); |
| ssl3_free(s); |
| return 0; |
| } |
| |
| s->d1 = d1; |
| |
| /* Set the version to the highest version for DTLS. This controls the initial |
| * state of |s->enc_method| and what the API reports as the version prior to |
| * negotiation. |
| * |
| * TODO(davidben): This is fragile and confusing. */ |
| s->version = DTLS1_2_VERSION; |
| return 1; |
| } |
| |
| static void dtls1_clear_queues(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); |
| } |
| |
| 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) { |
| ssl3_free(s); |
| |
| if (s == NULL || s->d1 == NULL) { |
| return; |
| } |
| |
| 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_supports_cipher(const SSL_CIPHER *cipher) { |
| /* DTLS does not support stream ciphers. */ |
| return cipher->algorithm_enc != SSL_RC4; |
| } |
| |
| void dtls1_start_timer(SSL *s) { |
| /* If timer is not set, initialize duration with 1 second */ |
| if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) { |
| s->d1->timeout_duration = 1; |
| } |
| |
| /* Set timeout to current time */ |
| get_current_time(s, &s->d1->next_timeout); |
| |
| /* Add duration to current time */ |
| s->d1->next_timeout.tv_sec += s->d1->timeout_duration; |
| BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, |
| &s->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 *s) { |
| struct timeval timeleft; |
| |
| /* Get time left until timeout, return false if no timer running */ |
| if (!DTLSv1_get_timeout(s, &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 *s) { |
| s->d1->timeout_duration *= 2; |
| if (s->d1->timeout_duration > 60) { |
| s->d1->timeout_duration = 60; |
| } |
| dtls1_start_timer(s); |
| } |
| |
| void dtls1_stop_timer(SSL *s) { |
| /* Reset everything */ |
| s->d1->num_timeouts = 0; |
| memset(&s->d1->next_timeout, 0, sizeof(struct timeval)); |
| s->d1->timeout_duration = 1; |
| BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, |
| &s->d1->next_timeout); |
| /* Clear retransmission buffer */ |
| dtls1_clear_record_buffer(s); |
| } |
| |
| int dtls1_check_timeout_num(SSL *s) { |
| s->d1->num_timeouts++; |
| |
| /* Reduce MTU after 2 unsuccessful retransmissions */ |
| if (s->d1->num_timeouts > DTLS1_MTU_TIMEOUTS && |
| !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) { |
| long mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, |
| NULL); |
| if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) { |
| s->d1->mtu = (unsigned)mtu; |
| } |
| } |
| |
| if (s->d1->num_timeouts > DTLS1_MAX_TIMEOUTS) { |
| /* fail the connection, enough alerts have been sent */ |
| OPENSSL_PUT_ERROR(SSL, dtls1_check_timeout_num, SSL_R_READ_TIMEOUT_EXPIRED); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| int DTLSv1_handle_timeout(SSL *ssl) { |
| 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_buffered_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 |
| } |
| |
| int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len) { |
| uint8_t *message = (uint8_t *)s->init_buf->data; |
| const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr; |
| uint8_t serialised_header[DTLS1_HM_HEADER_LENGTH]; |
| uint8_t *p = serialised_header; |
| |
| s->d1->handshake_write_seq = s->d1->next_handshake_write_seq; |
| s->d1->next_handshake_write_seq++; |
| |
| dtls1_set_message_header(s, htype, len, s->d1->handshake_write_seq, 0, len); |
| s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH; |
| s->init_off = 0; |
| |
| /* Buffer the message to handle re-xmits */ |
| dtls1_buffer_message(s, 0); |
| |
| /* Add the new message to the handshake hash. Serialize the message |
| * header as if it were a single fragment. */ |
| *p++ = msg_hdr->type; |
| l2n3(msg_hdr->msg_len, p); |
| s2n(msg_hdr->seq, p); |
| l2n3(0, p); |
| l2n3(msg_hdr->msg_len, p); |
| return ssl3_finish_mac(s, serialised_header, sizeof(serialised_header)) && |
| ssl3_finish_mac(s, message + DTLS1_HM_HEADER_LENGTH, len); |
| } |
| |
| int dtls1_handshake_write(SSL *s) { |
| return dtls1_do_write(s, SSL3_RT_HANDSHAKE, dtls1_use_current_epoch); |
| } |