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- /*
- * 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 <stdio.h>
- #include <openssl/objects.h>
- #include <openssl/rand.h>
- #include "ssl_local.h"
- #include "internal/time.h"
- static void get_current_time(struct timeval *t);
- 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_enc,
- tls1_mac_old,
- 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_enc,
- tls1_mac_old,
- 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
- };
- 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 *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;
- 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, (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)
- return 0;
- s->d1->mtu = larg;
- return larg;
- default:
- ret = ssl3_ctrl(ssl, cmd, larg, parg);
- break;
- }
- return ret;
- }
- void dtls1_start_timer(SSL_CONNECTION *s)
- {
- unsigned int sec, usec;
- SSL *ssl = SSL_CONNECTION_GET_SSL(s);
- #ifndef OPENSSL_NO_SCTP
- /* Disable timer for SCTP */
- if (BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
- memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
- return;
- }
- #endif
- /*
- * 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)
- s->d1->timeout_duration_us = s->d1->timer_cb(ssl, 0);
- else
- s->d1->timeout_duration_us = 1000000;
- }
- /* Set timeout to current time */
- get_current_time(&(s->d1->next_timeout));
- /* Add duration to current time */
- sec = s->d1->timeout_duration_us / 1000000;
- 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(ssl), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
- &(s->d1->next_timeout));
- }
- struct timeval *dtls1_get_timeout(SSL_CONNECTION *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_CONNECTION *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_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;
- memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
- s->d1->timeout_duration_us = 1000000;
- BIO_ctrl(s->rbio, 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_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);
- }
- static void get_current_time(struct timeval *t)
- {
- ossl_time_time_to_timeval(ossl_time_now(), t);
- }
- #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;
- }
- if (!ssl3_setup_buffers(s)) {
- /* ERR_raise() already called */
- return -1;
- }
- buf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
- if (buf == NULL) {
- ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
- return -1;
- }
- wbuf = RECORD_LAYER_get_wbuf(&s->rlayer)[0].buf;
- 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_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;
- 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;
- 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(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,
- NID_undef, NULL, NULL)) {
- /* SSLfatal already called */
- ret = -1;
- goto end;
- }
- ret = 1;
- end:
- BIO_ADDR_free(tmpclient);
- OPENSSL_free(buf);
- 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;
- }
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