diff options
Diffstat (limited to 'crypto/openssl/ssl/d1_lib.c')
| -rw-r--r-- | crypto/openssl/ssl/d1_lib.c | 983 |
1 files changed, 983 insertions, 0 deletions
diff --git a/crypto/openssl/ssl/d1_lib.c b/crypto/openssl/ssl/d1_lib.c new file mode 100644 index 000000000000..a5a52a7ee80e --- /dev/null +++ b/crypto/openssl/ssl/d1_lib.c @@ -0,0 +1,983 @@ +/* + * Copyright 2005-2025 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 "internal/e_winsock.h" /* struct timeval for DTLS_CTRL_GET_TIMEOUT */ +#include <stdio.h> +#include <openssl/objects.h> +#include <openssl/rand.h> +#include "ssl_local.h" +#include "internal/time.h" +#include "internal/ssl_unwrap.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, + 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_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; + + if (frag->msg_header.is_ccs + && frag->msg_header.saved_retransmit_state.wrlmethod != NULL + && s->rlayer.wrl != frag->msg_header.saved_retransmit_state.wrl) { + /* + * If we're freeing the CCS then we're done with the old wrl and it + * can bee freed + */ + frag->msg_header.saved_retransmit_state.wrlmethod->free(frag->msg_header.saved_retransmit_state.wrl); + } + + 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; + + if (s->d1 != NULL) { + dtls1_clear_queues(s); + pqueue_free(s->d1->buffered_messages); + pqueue_free(s->d1->sent_messages); + } + + DTLS_RECORD_LAYER_free(&s->rlayer); + + ssl3_free(ssl); + + 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_USER_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, versminor, 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; + } + + /* Get the record header */ + if (!PACKET_get_1(&pkt, &rectype) + || !PACKET_get_1(&pkt, &versmajor) + || !PACKET_get_1(&pkt, &versminor)) { + ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH); + goto end; + } + + if (s->msg_callback) + s->msg_callback(0, (versmajor << 8) | versminor, SSL3_RT_HEADER, buf, + DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg); + + 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; + } + + /* Save the sequence number: 64 bits, with top 2 bytes = epoch */ + if (!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 (sc == 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; +} |