X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fd1_lib.c;h=eb6a0f8295f1d46fa0e20de531b8fdd5ef7ecbbe;hp=d3b582a98cc810ec39cbcb723e7616ace75b8892;hb=67f78eadd00ce1c3a5bbde5e42530c1a61d363a2;hpb=b51bce942023325e727ca4225252d06c49d8f2b7 diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c index d3b582a98c..eb6a0f8295 100644 --- a/ssl/d1_lib.c +++ b/ssl/d1_lib.c @@ -1,81 +1,30 @@ -/* 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). + * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved. * + * Licensed under the OpenSSL license (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 #define USE_SOCKETS #include +#include #include "ssl_locl.h" -#if defined(OPENSSL_SYS_VMS) -# include -#elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_) -# include -#elif defined(OPENSSL_SYS_VXWORKS) +#if defined(OPENSSL_SYS_VXWORKS) # include #elif !defined(OPENSSL_SYS_WIN32) # include #endif static void get_current_time(struct timeval *t); -static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len); static int dtls1_handshake_write(SSL *s); -int dtls1_listen(SSL *s, struct sockaddr *client); +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, @@ -84,15 +33,13 @@ const SSL3_ENC_METHOD DTLSv1_enc_data = { 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_close_construct_packet, dtls1_handshake_write }; @@ -103,16 +50,14 @@ const SSL3_ENC_METHOD DTLSv1_2_enc_data = { 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_close_construct_packet, dtls1_handshake_write }; @@ -132,7 +77,7 @@ int dtls1_new(SSL *s) if (!DTLS_RECORD_LAYER_new(&s->rlayer)) { return 0; } - + if (!ssl3_new(s)) return (0); if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) { @@ -150,7 +95,7 @@ int dtls1_new(SSL *s) d1->link_mtu = 0; d1->mtu = 0; - if (!d1->buffered_messages || !d1->sent_messages) { + if (d1->buffered_messages == NULL || d1->sent_messages == NULL) { pqueue_free(d1->buffered_messages); pqueue_free(d1->sent_messages); OPENSSL_free(d1); @@ -164,6 +109,12 @@ int dtls1_new(SSL *s) } static void dtls1_clear_queues(SSL *s) +{ + dtls1_clear_received_buffer(s); + dtls1_clear_sent_buffer(s); +} + +void dtls1_clear_received_buffer(SSL *s) { pitem *item = NULL; hm_fragment *frag = NULL; @@ -173,6 +124,12 @@ static void dtls1_clear_queues(SSL *s) 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; @@ -181,6 +138,7 @@ static void dtls1_clear_queues(SSL *s) } } + void dtls1_free(SSL *s) { DTLS_RECORD_LAYER_free(&s->rlayer); @@ -198,10 +156,10 @@ void dtls1_free(SSL *s) void dtls1_clear(SSL *s) { - pqueue buffered_messages; - pqueue sent_messages; - unsigned int mtu; - unsigned int link_mtu; + pqueue *buffered_messages; + pqueue *sent_messages; + size_t mtu; + size_t link_mtu; DTLS_RECORD_LAYER_clear(&s->rlayer); @@ -229,10 +187,13 @@ void dtls1_clear(SSL *s) } ssl3_clear(s); - if (s->options & SSL_OP_CISCO_ANYCONNECT) + + if (s->method->version == DTLS_ANY_VERSION) + s->version = DTLS_MAX_VERSION; +#ifndef OPENSSL_NO_DTLS1_METHOD + else 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; +#endif else s->version = s->method->version; } @@ -250,31 +211,6 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 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; @@ -298,25 +234,6 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg) 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 @@ -372,7 +289,7 @@ struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft) /* * If remaining time is less than 15 ms, set it to 0 to prevent issues - * because of small devergences with socket timeouts. + * because of small divergences with socket timeouts. */ if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) { memset(timeleft, 0, sizeof(*timeleft)); @@ -416,12 +333,12 @@ void dtls1_stop_timer(SSL *s) 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); + dtls1_clear_sent_buffer(s); } int dtls1_check_timeout_num(SSL *s) { - unsigned int mtu; + size_t mtu; s->d1->timeout.num_alerts++; @@ -429,8 +346,7 @@ int dtls1_check_timeout_num(SSL *s) 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); + BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL); if (mtu < s->d1->mtu) s->d1->mtu = mtu; } @@ -460,12 +376,6 @@ int dtls1_handle_timeout(SSL *s) 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); @@ -482,57 +392,563 @@ static void get_current_time(struct timeval *t) GetSystemTime(&st); SystemTimeToFileTime(&st, &now.ft); + /* re-bias to 1/1/1970 */ # ifdef __MINGW32__ now.ul -= 116444736000000000ULL; # else - now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */ + /* *INDENT-OFF* */ + now.ul -= 116444736000000000UI64; + /* *INDENT-ON* */ # 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) +#define LISTEN_SUCCESS 2 +#define LISTEN_SEND_VERIFY_REQUEST 1 + +#ifndef OPENSSL_NO_SOCK +int DTLSv1_listen(SSL *s, BIO_ADDR *client) { - int ret; + int next, n, ret = 0, clearpkt = 0; + unsigned char cookie[DTLS1_COOKIE_LENGTH]; + unsigned char seq[SEQ_NUM_SIZE]; + const unsigned char *data; + unsigned char *buf; + size_t fragoff, fraglen, msglen; + unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen; + BIO *rbio, *wbio; + BUF_MEM *bufm; + BIO_ADDR *tmpclient = NULL; + PACKET pkt, msgpkt, msgpayload, session, cookiepkt; + + if (s->handshake_func == NULL) { + /* Not properly initialized yet */ + SSL_set_accept_state(s); + } /* Ensure there is no state left over from a previous invocation */ if (!SSL_clear(s)) return -1; + ERR_clear_error(); + + rbio = SSL_get_rbio(s); + wbio = SSL_get_wbio(s); + + if (!rbio || !wbio) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET); + return -1; + } + + /* + * We only peek at incoming ClientHello's until we're sure we are going to + * to respond with a HelloVerifyRequest. If its a ClientHello with a valid + * cookie then we leave it in the BIO for accept to handle. + */ + BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL); + + /* + * 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)) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION); + return -1; + } + + if (s->init_buf == NULL) { + if ((bufm = BUF_MEM_new()) == NULL) { + SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE); + return -1; + } + + if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) { + BUF_MEM_free(bufm); + SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE); + return -1; + } + s->init_buf = bufm; + } + buf = (unsigned char *)s->init_buf->data; + + do { + /* Get a packet */ + + clear_sys_error(); + /* + * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH + * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store + * the record header as well, but we do here. We've set up init_buf to + * be the standard size for simplicity. In practice we shouldn't ever + * receive a ClientHello as long as this. If we do it will get dropped + * in the record length check below. + */ + n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH); + + if (n <= 0) { + if (BIO_should_retry(rbio)) { + /* Non-blocking IO */ + goto end; + } + return -1; + } + + /* If we hit any problems we need to clear this packet from the BIO */ + clearpkt = 1; + + if (!PACKET_buf_init(&pkt, buf, n)) { + SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR); + return -1; + } + + /* + * 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) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL); + goto end; + } + + if (s->msg_callback) + s->msg_callback(0, 0, SSL3_RT_HEADER, buf, + DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); + + /* Get the record header */ + if (!PACKET_get_1(&pkt, &rectype) + || !PACKET_get_1(&pkt, &versmajor)) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH); + goto end; + } + + if (rectype != SSL3_RT_HANDSHAKE) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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)) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH); + goto end; + } + + if (msgtype != SSL3_MT_CLIENT_HELLO) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE); + goto end; + } + + /* Message sequence number can only be 0 or 1 */ + if (msgseq > 2) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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) */ + SSLerr(SSL_F_DTLSV1_LISTEN, 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, s, + s->msg_callback_arg); + + if (!PACKET_get_net_2(&msgpayload, &clientvers)) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH); + goto end; + } + + /* + * Verify client version is supported + */ + if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) && + s->method->version != DTLS_ANY_VERSION) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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. + */ + SSLerr(SSL_F_DTLSV1_LISTEN, 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 (s->ctx->app_verify_cookie_cb == NULL) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK); + /* This is fatal */ + return -1; + } + if (s->ctx->app_verify_cookie_cb(s, 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. + */ + + /* + * Dump the read packet, we don't need it any more. Ignore return + * value + */ + BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL); + BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH); + BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL); + + /* Generate the cookie */ + if (s->ctx->app_gen_cookie_cb == NULL || + s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 || + cookielen > 255) { + SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE); + /* This is fatal */ + return -1; + } + + /* + * 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 = (s->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION + : s->version; + + /* Construct the record and message headers */ + if (!WPACKET_init(&wpkt, s->init_buf) + || !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)) { + SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR); + WPACKET_cleanup(&wpkt); + /* This is fatal */ + return -1; + } + + /* + * 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(&buf[DTLS1_RT_HEADER_LENGTH + 1], + &buf[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, s, s->msg_callback_arg); + + if ((tmpclient = BIO_ADDR_new()) == NULL) { + SSLerr(SSL_F_DTLSV1_LISTEN, 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; + + /* TODO(size_t): convert this call */ + if (BIO_write(wbio, buf, 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; + } + return -1; + } + + 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; + } + return -1; + } + } + } 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(s, SSL_OP_COOKIE_EXCHANGE); - s->d1->listen = 1; - ret = SSL_accept(s); - if (ret <= 0) - return ret; + /* + * Tell the state machine that we've done the initial hello verify + * exchange + */ + ossl_statem_set_hello_verify_done(s); - (void)BIO_dgram_get_peer(SSL_get_rbio(s), client); - return 1; + /* + * 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); + + ret = 1; + clearpkt = 0; + end: + BIO_ADDR_free(tmpclient); + BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL); + if (clearpkt) { + /* Dump this packet. Ignore return value */ + BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH); + } + return ret; } +#endif -static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len) +static int dtls1_handshake_write(SSL *s) { - 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 */ + return dtls1_do_write(s, SSL3_RT_HANDSHAKE); +} - if (!dtls1_buffer_message(s, 0)) - return 0; +int dtls1_shutdown(SSL *s) +{ + int ret; +#ifndef OPENSSL_NO_SCTP + BIO *wbio; + + wbio = SSL_get_wbio(s); + if (wbio != NULL && BIO_dgram_is_sctp(wbio) && + !(s->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 *s) +{ + if (s->d1->link_mtu) { + s->d1->mtu = + s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); + 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(s) & SSL_OP_NO_QUERY_MTU)) { + s->d1->mtu = + BIO_ctrl(SSL_get_wbio(s), 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(s), BIO_CTRL_DGRAM_SET_MTU, + (long)s->d1->mtu, NULL); + } + } else + return 0; + } return 1; } -static int dtls1_handshake_write(SSL *s) +static size_t dtls1_link_min_mtu(void) { - return dtls1_do_write(s, SSL3_RT_HANDSHAKE); + return (g_probable_mtu[(sizeof(g_probable_mtu) / + sizeof(g_probable_mtu[0])) - 1]); +} + +size_t dtls1_min_mtu(SSL *s) +{ + return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s)); +} + +size_t DTLS_get_data_mtu(const SSL *s) +{ + size_t mac_overhead, int_overhead, blocksize, ext_overhead; + const SSL_CIPHER *ciph = SSL_get_current_cipher(s); + size_t 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; }