/* ssl/d1_lib.c */ /* * 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 <stdio.h> #define USE_SOCKETS #include <openssl/objects.h> #include "ssl_locl.h" #if defined(OPENSSL_SYS_VMS) # include <sys/timeb.h> #endif static void get_current_time(struct timeval *t); static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len); static int dtls1_handshake_write(SSL *s); const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT; int dtls1_listen(SSL *s, struct sockaddr *client); SSL3_ENC_METHOD DTLSv1_enc_data = { tls1_enc, tls1_mac, tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_mac, TLS1_FINISH_MAC_LENGTH, tls1_cert_verify_mac, TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE, TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE, tls1_alert_code, tls1_export_keying_material, SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV, DTLS1_HM_HEADER_LENGTH, dtls1_set_handshake_header, dtls1_handshake_write }; SSL3_ENC_METHOD DTLSv1_2_enc_data = { tls1_enc, tls1_mac, tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_mac, TLS1_FINISH_MAC_LENGTH, tls1_cert_verify_mac, TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE, TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE, tls1_alert_code, tls1_export_keying_material, 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_HM_HEADER_LENGTH, dtls1_set_handshake_header, 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 (!ssl3_new(s)) return (0); if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL) return (0); memset(d1, 0, sizeof *d1); /* d1->handshake_epoch=0; */ d1->unprocessed_rcds.q = pqueue_new(); d1->processed_rcds.q = pqueue_new(); d1->buffered_messages = pqueue_new(); d1->sent_messages = pqueue_new(); d1->buffered_app_data.q = pqueue_new(); if (s->server) { d1->cookie_len = sizeof(s->d1->cookie); } d1->link_mtu = 0; d1->mtu = 0; if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q || !d1->buffered_messages || !d1->sent_messages || !d1->buffered_app_data.q) { if (d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q); if (d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q); if (d1->buffered_messages) pqueue_free(d1->buffered_messages); if (d1->sent_messages) pqueue_free(d1->sent_messages); if (d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q); OPENSSL_free(d1); return (0); } s->d1 = d1; s->method->ssl_clear(s); return (1); } static void dtls1_clear_queues(SSL *s) { pitem *item = NULL; DTLS1_RECORD_DATA *rdata; while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) { rdata = (DTLS1_RECORD_DATA *)item->data; if (rdata->rbuf.buf) { OPENSSL_free(rdata->rbuf.buf); } OPENSSL_free(item->data); pitem_free(item); } while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) { rdata = (DTLS1_RECORD_DATA *)item->data; if (rdata->rbuf.buf) { OPENSSL_free(rdata->rbuf.buf); } OPENSSL_free(item->data); pitem_free(item); } while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) { rdata = (DTLS1_RECORD_DATA *)item->data; if (rdata->rbuf.buf) { OPENSSL_free(rdata->rbuf.buf); } OPENSSL_free(item->data); pitem_free(item); } 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) { ssl3_free(s); dtls1_clear_queues(s); pqueue_free(s->d1->unprocessed_rcds.q); pqueue_free(s->d1->processed_rcds.q); pqueue_free(s->d1->buffered_messages); pqueue_free(s->d1->sent_messages); pqueue_free(s->d1->buffered_app_data.q); OPENSSL_free(s->d1); s->d1 = NULL; } void dtls1_clear(SSL *s) { pqueue unprocessed_rcds; pqueue processed_rcds; pqueue buffered_messages; pqueue sent_messages; pqueue buffered_app_data; unsigned int mtu; unsigned int link_mtu; if (s->d1) { unprocessed_rcds = s->d1->unprocessed_rcds.q; processed_rcds = s->d1->processed_rcds.q; buffered_messages = s->d1->buffered_messages; sent_messages = s->d1->sent_messages; buffered_app_data = s->d1->buffered_app_data.q; mtu = s->d1->mtu; link_mtu = s->d1->link_mtu; dtls1_clear_queues(s); memset(s->d1, 0, sizeof(*(s->d1))); 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->unprocessed_rcds.q = unprocessed_rcds; s->d1->processed_rcds.q = processed_rcds; s->d1->buffered_messages = buffered_messages; s->d1->sent_messages = sent_messages; s->d1->buffered_app_data.q = buffered_app_data; } ssl3_clear(s); if (s->options & SSL_OP_CISCO_ANYCONNECT) s->client_version = s->version = DTLS1_BAD_VER; else if (s->method->version == DTLS_ANY_VERSION) s->version = DTLS1_2_VERSION; else s->version = s->method->version; } 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_LISTEN: ret = dtls1_listen(s, parg); break; case SSL_CTRL_CHECK_PROTO_VERSION: /* * For library-internal use; checks that the current protocol is the * highest enabled version (according to s->ctx->method, as version * negotiation may have changed s->method). */ if (s->version == s->ctx->method->version) return 1; /* * Apparently we're using a version-flexible SSL_METHOD (not at its * highest protocol version). */ if (s->ctx->method->version == DTLS_method()->version) { #if DTLS_MAX_VERSION != DTLS1_2_VERSION # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION. #endif if (!(s->options & SSL_OP_NO_DTLSv1_2)) return s->version == DTLS1_2_VERSION; if (!(s->options & SSL_OP_NO_DTLSv1)) return s->version == DTLS1_VERSION; } return 0; /* Unexpected state; fail closed. */ 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) return 0; s->d1->mtu = larg; return larg; default: ret = ssl3_ctrl(s, cmd, larg, parg); break; } return (ret); } /* * As it's impossible to use stream ciphers in "datagram" mode, this * simple filter is designed to disengage them in DTLS. Unfortunately * there is no universal way to identify stream SSL_CIPHER, so we have * to explicitly list their SSL_* codes. Currently RC4 is the only one * available, but if new ones emerge, they will have to be added... */ const SSL_CIPHER *dtls1_get_cipher(unsigned int u) { const SSL_CIPHER *ciph = ssl3_get_cipher(u); if (ciph != NULL) { if (ciph->algorithm_enc == SSL_RC4) return NULL; } return ciph; } void dtls1_start_timer(SSL *s) { #ifndef OPENSSL_NO_SCTP /* Disable timer for SCTP */ if (BIO_dgram_is_sctp(SSL_get_wbio(s))) { memset(&(s->d1->next_timeout), 0, sizeof(struct timeval)); return; } #endif /* 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->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)); } 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(struct timeval)); 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 devergences with socket timeouts. */ if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) { memset(timeleft, 0, sizeof(struct timeval)); } 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; } 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 */ memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st)); 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_sent_buffer(s); } int dtls1_check_timeout_num(SSL *s) { unsigned int 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 */ SSLerr(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; } dtls1_double_timeout(s); if (dtls1_check_timeout_num(s) < 0) return -1; s->d1->timeout.read_timeouts++; if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) { s->d1->timeout.read_timeouts = 1; } #ifndef OPENSSL_NO_HEARTBEATS if (s->tlsext_hb_pending) { s->tlsext_hb_pending = 0; return dtls1_heartbeat(s); } #endif dtls1_start_timer(s); 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); # ifdef __MINGW32__ now.ul -= 116444736000000000ULL; # else now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */ # endif t->tv_sec = (long)(now.ul / 10000000); t->tv_usec = ((int)(now.ul % 10000000)) / 10; #elif defined(OPENSSL_SYS_VMS) struct timeb tb; ftime(&tb); t->tv_sec = (long)tb.time; t->tv_usec = (long)tb.millitm * 1000; #else gettimeofday(t, NULL); #endif } int dtls1_listen(SSL *s, struct sockaddr *client) { int ret; /* Ensure there is no state left over from a previous invocation */ SSL_clear(s); SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE); s->d1->listen = 1; ret = SSL_accept(s); if (ret <= 0) return ret; (void)BIO_dgram_get_peer(SSL_get_rbio(s), client); return 1; } static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len) { unsigned char *p = (unsigned char *)s->init_buf->data; dtls1_set_message_header(s, p, htype, len, 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); } static int dtls1_handshake_write(SSL *s) { return dtls1_do_write(s, SSL3_RT_HANDSHAKE); }