- /* DTLS implementation written by Nagendra Modadugu
- * (nagendra@cs.stanford.edu) for the OpenSSL project 2005. */
- /* ====================================================================
- * Copyright (c) 1998-2005 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 (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * 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 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 acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS 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 AUTHOR OR 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.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.] */
-
- #include <openssl/ssl.h>
-
- #include <assert.h>
- #include <string.h>
-
- #include <openssl/bio.h>
- #include <openssl/buf.h>
- #include <openssl/bytestring.h>
- #include <openssl/mem.h>
- #include <openssl/evp.h>
- #include <openssl/err.h>
- #include <openssl/rand.h>
-
- #include "../crypto/internal.h"
- #include "internal.h"
-
-
- int dtls1_get_record(SSL *ssl) {
- again:
- switch (ssl->s3->recv_shutdown) {
- case ssl_shutdown_none:
- break;
- case ssl_shutdown_fatal_alert:
- OPENSSL_PUT_ERROR(SSL, SSL_R_PROTOCOL_IS_SHUTDOWN);
- return -1;
- case ssl_shutdown_close_notify:
- return 0;
- }
-
- /* Read a new packet if there is no unconsumed one. */
- if (ssl_read_buffer_len(ssl) == 0) {
- int read_ret = ssl_read_buffer_extend_to(ssl, 0 /* unused */);
- if (read_ret < 0 && dtls1_is_timer_expired(ssl)) {
- /* For blocking BIOs, retransmits must be handled internally. */
- int timeout_ret = DTLSv1_handle_timeout(ssl);
- if (timeout_ret <= 0) {
- return timeout_ret;
- }
- goto again;
- }
- if (read_ret <= 0) {
- return read_ret;
- }
- }
- assert(ssl_read_buffer_len(ssl) > 0);
-
- CBS body;
- uint8_t type, alert;
- size_t consumed;
- enum ssl_open_record_t open_ret =
- dtls_open_record(ssl, &type, &body, &consumed, &alert,
- ssl_read_buffer(ssl), ssl_read_buffer_len(ssl));
- ssl_read_buffer_consume(ssl, consumed);
- switch (open_ret) {
- case ssl_open_record_partial:
- /* Impossible in DTLS. */
- break;
-
- case ssl_open_record_success:
- if (CBS_len(&body) > 0xffff) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- return -1;
- }
-
- SSL3_RECORD *rr = &ssl->s3->rrec;
- rr->type = type;
- rr->length = (uint16_t)CBS_len(&body);
- rr->data = (uint8_t *)CBS_data(&body);
- return 1;
-
- case ssl_open_record_discard:
- goto again;
-
- case ssl_open_record_close_notify:
- return 0;
-
- case ssl_open_record_fatal_alert:
- return -1;
-
- case ssl_open_record_error:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return -1;
- }
-
- assert(0);
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- int dtls1_read_app_data(SSL *ssl, int *out_got_handshake, uint8_t *buf, int len,
- int peek) {
- assert(!SSL_in_init(ssl));
-
- *out_got_handshake = 0;
- SSL3_RECORD *rr = &ssl->s3->rrec;
-
- again:
- if (rr->length == 0) {
- int ret = dtls1_get_record(ssl);
- if (ret <= 0) {
- return ret;
- }
- }
-
- if (rr->type == SSL3_RT_HANDSHAKE) {
- /* Parse the first fragment header to determine if this is a pre-CCS or
- * post-CCS handshake record. DTLS resets handshake message numbers on each
- * handshake, so renegotiations and retransmissions are ambiguous. */
- CBS cbs, body;
- struct hm_header_st msg_hdr;
- CBS_init(&cbs, rr->data, rr->length);
- if (!dtls1_parse_fragment(&cbs, &msg_hdr, &body)) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
- return -1;
- }
-
- if (msg_hdr.type == SSL3_MT_FINISHED &&
- msg_hdr.seq == ssl->d1->handshake_read_seq - 1) {
- if (msg_hdr.frag_off == 0) {
- /* Retransmit our last flight of messages. If the peer sends the second
- * Finished, they may not have received ours. Only do this for the
- * first fragment, in case the Finished was fragmented. */
- if (dtls1_check_timeout_num(ssl) < 0) {
- return -1;
- }
-
- dtls1_retransmit_outgoing_messages(ssl);
- }
-
- rr->length = 0;
- goto again;
- }
-
- /* Otherwise, this is a pre-CCS handshake message from an unsupported
- * renegotiation attempt. Fall through to the error path. */
- }
-
- if (rr->type != SSL3_RT_APPLICATION_DATA) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
- return -1;
- }
-
- /* Discard empty records. */
- if (rr->length == 0) {
- goto again;
- }
-
- if (len <= 0) {
- return len;
- }
-
- if ((unsigned)len > rr->length) {
- len = rr->length;
- }
-
- OPENSSL_memcpy(buf, rr->data, len);
- if (!peek) {
- /* TODO(davidben): Should the record be truncated instead? This is a
- * datagram transport. See https://crbug.com/boringssl/65. */
- rr->length -= len;
- rr->data += len;
- if (rr->length == 0) {
- /* The record has been consumed, so we may now clear the buffer. */
- ssl_read_buffer_discard(ssl);
- }
- }
-
- return len;
- }
-
- int dtls1_read_change_cipher_spec(SSL *ssl) {
- SSL3_RECORD *rr = &ssl->s3->rrec;
-
- again:
- if (rr->length == 0) {
- int ret = dtls1_get_record(ssl);
- if (ret <= 0) {
- return ret;
- }
- }
-
- /* Drop handshake records silently. The epochs match, so this must be a
- * retransmit of a message we already received. */
- if (rr->type == SSL3_RT_HANDSHAKE) {
- rr->length = 0;
- goto again;
- }
-
- /* Other record types are illegal in this epoch. Note all application data
- * records come in the encrypted epoch. */
- if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
- return -1;
- }
-
- if (rr->length != 1 || rr->data[0] != SSL3_MT_CCS) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_CHANGE_CIPHER_SPEC);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return -1;
- }
-
- ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data,
- rr->length);
-
- rr->length = 0;
- ssl_read_buffer_discard(ssl);
- return 1;
- }
-
- void dtls1_read_close_notify(SSL *ssl) {
- /* Bidirectional shutdown doesn't make sense for an unordered transport. DTLS
- * alerts also aren't delivered reliably, so we may even time out because the
- * peer never received our close_notify. Report to the caller that the channel
- * has fully shut down. */
- if (ssl->s3->recv_shutdown == ssl_shutdown_none) {
- ssl->s3->recv_shutdown = ssl_shutdown_close_notify;
- }
- }
-
- int dtls1_write_app_data(SSL *ssl, const uint8_t *buf, int len) {
- assert(!SSL_in_init(ssl));
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG);
- return -1;
- }
-
- if (len < 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_LENGTH);
- return -1;
- }
-
- if (len == 0) {
- return 0;
- }
-
- int ret = dtls1_write_record(ssl, SSL3_RT_APPLICATION_DATA, buf, (size_t)len,
- dtls1_use_current_epoch);
- if (ret <= 0) {
- return ret;
- }
- return len;
- }
-
- int dtls1_write_record(SSL *ssl, int type, const uint8_t *buf, size_t len,
- enum dtls1_use_epoch_t use_epoch) {
- assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
- /* There should never be a pending write buffer in DTLS. One can't write half
- * a datagram, so the write buffer is always dropped in
- * |ssl_write_buffer_flush|. */
- assert(!ssl_write_buffer_is_pending(ssl));
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- size_t max_out = len + SSL_max_seal_overhead(ssl);
- uint8_t *out;
- size_t ciphertext_len;
- if (!ssl_write_buffer_init(ssl, &out, max_out) ||
- !dtls_seal_record(ssl, out, &ciphertext_len, max_out, type, buf, len,
- use_epoch)) {
- ssl_write_buffer_clear(ssl);
- return -1;
- }
- ssl_write_buffer_set_len(ssl, ciphertext_len);
-
- int ret = ssl_write_buffer_flush(ssl);
- if (ret <= 0) {
- return ret;
- }
- return 1;
- }
-
- int dtls1_dispatch_alert(SSL *ssl) {
- int ret = dtls1_write_record(ssl, SSL3_RT_ALERT, &ssl->s3->send_alert[0], 2,
- dtls1_use_current_epoch);
- if (ret <= 0) {
- return ret;
- }
- ssl->s3->alert_dispatch = 0;
-
- /* If the alert is fatal, flush the BIO now. */
- if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {
- BIO_flush(ssl->wbio);
- }
-
- ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_ALERT, ssl->s3->send_alert,
- 2);
-
- int alert = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1];
- ssl_do_info_callback(ssl, SSL_CB_WRITE_ALERT, alert);
-
- return 1;
- }
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