/* * Copyright 2005-2022 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (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 "internal/e_os.h" #include #include #include #include "ssl_local.h" #include "internal/time.h" static int dtls1_handshake_write(SSL_CONNECTION *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_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_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_set_handshake_header, dtls1_close_construct_packet, dtls1_handshake_write }; const SSL3_ENC_METHOD DTLSv1_2_enc_data = { tls1_setup_key_block, tls1_generate_master_secret, tls1_change_cipher_state, tls1_final_finish_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_set_handshake_header, dtls1_close_construct_packet, dtls1_handshake_write }; OSSL_TIME 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 ossl_seconds2time(60 * 60 * 2); } int dtls1_new(SSL *ssl) { DTLS1_STATE *d1; SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return 0; if (!DTLS_RECORD_LAYER_new(&s->rlayer)) { return 0; } if (!ssl3_new(ssl)) return 0; if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) { ssl3_free(ssl); return 0; } 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(ssl); return 0; } s->d1 = d1; if (!ssl->method->ssl_clear(ssl)) return 0; return 1; } static void dtls1_clear_queues(SSL_CONNECTION *s) { dtls1_clear_received_buffer(s); dtls1_clear_sent_buffer(s); } void dtls1_clear_received_buffer(SSL_CONNECTION *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_CONNECTION *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 *ssl) { SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return; DTLS_RECORD_LAYER_free(&s->rlayer); ssl3_free(ssl); 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 *ssl) { pqueue *buffered_messages; pqueue *sent_messages; size_t mtu; size_t link_mtu; SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return 0; 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(ssl) & 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(ssl)) return 0; if (ssl->method->version == DTLS_ANY_VERSION) s->version = DTLS_MAX_VERSION_INTERNAL; #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 = ssl->method->version; return 1; } long dtls1_ctrl(SSL *ssl, int cmd, long larg, void *parg) { int ret = 0; OSSL_TIME t; SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return 0; switch (cmd) { case DTLS_CTRL_GET_TIMEOUT: if (dtls1_get_timeout(s, &t)) { *(struct timeval *)parg = ossl_time_to_timeval(t); 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) return 0; s->d1->mtu = larg; return larg; default: ret = ssl3_ctrl(ssl, cmd, larg, parg); break; } return ret; } static void dtls1_bio_set_next_timeout(BIO * bio, const DTLS1_STATE *d1) { struct timeval tv = ossl_time_to_timeval(d1->next_timeout); BIO_ctrl(bio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &tv); } void dtls1_start_timer(SSL_CONNECTION *s) { OSSL_TIME duration; SSL *ssl = SSL_CONNECTION_GET_SSL(s); #ifndef OPENSSL_NO_SCTP /* Disable timer for SCTP */ if (BIO_dgram_is_sctp(SSL_get_wbio(ssl))) { s->d1->next_timeout = ossl_time_zero(); return; } #endif /* * If timer is not set, initialize duration with 1 second or * a user-specified value if the timer callback is installed. */ if (ossl_time_is_zero(s->d1->next_timeout)) { if (s->d1->timer_cb != NULL) s->d1->timeout_duration_us = s->d1->timer_cb(ssl, 0); else s->d1->timeout_duration_us = 1000000; } /* Set timeout to current time plus duration */ duration = ossl_us2time(s->d1->timeout_duration_us); s->d1->next_timeout = ossl_time_add(ossl_time_now(), duration); /* set s->d1->next_timeout into ssl->rbio interface */ dtls1_bio_set_next_timeout(SSL_get_rbio(ssl), s->d1); } int dtls1_get_timeout(const SSL_CONNECTION *s, OSSL_TIME *timeleft) { OSSL_TIME timenow; /* If no timeout is set, just return NULL */ if (ossl_time_is_zero(s->d1->next_timeout)) return 0; /* Get current time */ timenow = ossl_time_now(); /* * If timer already expired or if remaining time is less than 15 ms, * set it to 0 to prevent issues because of small divergences with * socket timeouts. */ *timeleft = ossl_time_subtract(s->d1->next_timeout, timenow); if (ossl_time_compare(*timeleft, ossl_ms2time(15)) <= 0) *timeleft = ossl_time_zero(); return 1; } int dtls1_is_timer_expired(SSL_CONNECTION *s) { OSSL_TIME timeleft; /* Get time left until timeout, return false if no timer running */ if (!dtls1_get_timeout(s, &timeleft)) return 0; /* Return false if timer is not expired yet */ if (!ossl_time_is_zero(timeleft)) return 0; /* Timer expired, so return true */ return 1; } static void dtls1_double_timeout(SSL_CONNECTION *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_CONNECTION *s) { /* Reset everything */ s->d1->timeout_num_alerts = 0; s->d1->next_timeout = ossl_time_zero(); s->d1->timeout_duration_us = 1000000; dtls1_bio_set_next_timeout(s->rbio, s->d1); /* Clear retransmission buffer */ dtls1_clear_sent_buffer(s); } int dtls1_check_timeout_num(SSL_CONNECTION *s) { size_t mtu; SSL *ssl = SSL_CONNECTION_GET_SSL(s); s->d1->timeout_num_alerts++; /* Reduce MTU after 2 unsuccessful retransmissions */ if (s->d1->timeout_num_alerts > 2 && !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) { mtu = BIO_ctrl(SSL_get_wbio(ssl), 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_R_READ_TIMEOUT_EXPIRED); return -1; } return 0; } int dtls1_handle_timeout(SSL_CONNECTION *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(SSL_CONNECTION_GET_SSL(s), s->d1->timeout_duration_us); else dtls1_double_timeout(s); if (dtls1_check_timeout_num(s) < 0) { /* SSLfatal() already called */ return -1; } dtls1_start_timer(s); /* Calls SSLfatal() if required */ return dtls1_retransmit_buffered_messages(s); } #define LISTEN_SUCCESS 2 #define LISTEN_SEND_VERIFY_REQUEST 1 #ifndef OPENSSL_NO_SOCK int DTLSv1_listen(SSL *ssl, 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 = NULL, *wbuf; size_t fragoff, fraglen, msglen; unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen; BIO *rbio, *wbio; BIO_ADDR *tmpclient = NULL; PACKET pkt, msgpkt, msgpayload, session, cookiepkt; SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return -1; if (s->handshake_func == NULL) { /* Not properly initialized yet */ SSL_set_accept_state(ssl); } /* Ensure there is no state left over from a previous invocation */ if (!SSL_clear(ssl)) return -1; ERR_clear_error(); rbio = SSL_get_rbio(ssl); wbio = SSL_get_wbio(ssl); if (!rbio || !wbio) { ERR_raise(ERR_LIB_SSL, 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)) { ERR_raise(ERR_LIB_SSL, SSL_R_UNSUPPORTED_SSL_VERSION); return -1; } buf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH); if (buf == NULL) return -1; wbuf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH); if (wbuf == NULL) { OPENSSL_free(buf); return -1; } 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; } ret = -1; goto end; } if (!PACKET_buf_init(&pkt, buf, n)) { ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } /* * 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) { ERR_raise(ERR_LIB_SSL, SSL_R_RECORD_TOO_SMALL); goto end; } if (s->msg_callback) s->msg_callback(0, 0, SSL3_RT_HEADER, buf, DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg); /* Get the record header */ if (!PACKET_get_1(&pkt, &rectype) || !PACKET_get_1(&pkt, &versmajor)) { ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH); goto end; } if (rectype != SSL3_RT_HANDSHAKE) { ERR_raise(ERR_LIB_SSL, 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) { ERR_raise(ERR_LIB_SSL, 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)) { ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH); goto end; } /* * 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) { ERR_raise(ERR_LIB_SSL, 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) { ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH); goto end; } if (msgtype != SSL3_MT_CLIENT_HELLO) { ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE); goto end; } /* Message sequence number can only be 0 or 1 */ if (msgseq > 2) { ERR_raise(ERR_LIB_SSL, 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) */ ERR_raise(ERR_LIB_SSL, 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, ssl, s->msg_callback_arg); if (!PACKET_get_net_2(&msgpayload, &clientvers)) { ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH); goto end; } /* * Verify client version is supported */ if (DTLS_VERSION_LT(clientvers, (unsigned int)ssl->method->version) && ssl->method->version != DTLS_ANY_VERSION) { ERR_raise(ERR_LIB_SSL, 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. */ ERR_raise(ERR_LIB_SSL, 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 (ssl->ctx->app_verify_cookie_cb == NULL) { ERR_raise(ERR_LIB_SSL, SSL_R_NO_VERIFY_COOKIE_CALLBACK); /* This is fatal */ ret = -1; goto end; } if (ssl->ctx->app_verify_cookie_cb(ssl, 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 (ssl->ctx->app_gen_cookie_cb == NULL || ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0 || cookielen > 255) { ERR_raise(ERR_LIB_SSL, SSL_R_COOKIE_GEN_CALLBACK_FAILURE); /* This is fatal */ ret = -1; goto end; } /* * 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 = (ssl->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)) { ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR); WPACKET_cleanup(&wpkt); /* This is fatal */ ret = -1; goto end; } /* * 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, ssl, s->msg_callback_arg); if ((tmpclient = BIO_ADDR_new()) == NULL) { ERR_raise(ERR_LIB_SSL, ERR_R_BIO_LIB); 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; 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; } ret = -1; goto end; } 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; } ret = -1; goto end; } } } 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; s->rlayer.wrlmethod->increment_sequence_ctr(s->rlayer.wrl); /* * We are doing cookie exchange, so make sure we set that option in the * SSL object */ SSL_set_options(ssl, 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 for use by the record layer */ if (BIO_write(s->rlayer.rrlnext, buf, n) != n) { ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR); ret = -1; goto end; } /* * Reset the record layer - but this time we can use the record we just * buffered in s->rlayer.rrlnext */ if (!ssl_set_new_record_layer(s, DTLS_ANY_VERSION, OSSL_RECORD_DIRECTION_READ, OSSL_RECORD_PROTECTION_LEVEL_NONE, NULL, 0, NULL, 0, NULL, 0, NULL, 0, NULL, 0, NID_undef, NULL, NULL, NULL)) { /* SSLfatal already called */ ret = -1; goto end; } ret = 1; end: BIO_ADDR_free(tmpclient); OPENSSL_free(buf); OPENSSL_free(wbuf); return ret; } #endif static int dtls1_handshake_write(SSL_CONNECTION *s) { return dtls1_do_write(s, SSL3_RT_HANDSHAKE); } int dtls1_shutdown(SSL *s) { int ret; #ifndef OPENSSL_NO_SCTP BIO *wbio; SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL_ONLY(s); if (s == NULL) return -1; wbio = SSL_get_wbio(s); if (wbio != NULL && BIO_dgram_is_sctp(wbio) && !(sc->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_CONNECTION *s) { SSL *ssl = SSL_CONNECTION_GET_SSL(s); if (s->d1->link_mtu) { s->d1->mtu = s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl)); 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(ssl) & SSL_OP_NO_QUERY_MTU)) { s->d1->mtu = BIO_ctrl(SSL_get_wbio(ssl), 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(ssl), 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_CONNECTION *s) { SSL *ssl = SSL_CONNECTION_GET_SSL(s); return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl)); } size_t DTLS_get_data_mtu(const SSL *ssl) { size_t mac_overhead, int_overhead, blocksize, ext_overhead; const SSL_CIPHER *ciph = SSL_get_current_cipher(ssl); size_t mtu; const SSL_CONNECTION *s = SSL_CONNECTION_FROM_CONST_SSL_ONLY(ssl); if (s == NULL) return 0; 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 *ssl, DTLS_timer_cb cb) { SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl); if (s == NULL) return; s->d1->timer_cb = cb; }