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- /* 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 <stdio.h>
- #include <string.h>
-
- #include <openssl/buf.h>
- #include <openssl/mem.h>
- #include <openssl/evp.h>
- #include <openssl/err.h>
- #include <openssl/rand.h>
-
- #include "internal.h"
-
-
- static int do_dtls1_write(SSL *ssl, int type, const uint8_t *buf,
- unsigned int len, enum dtls1_use_epoch_t use_epoch);
-
- /* dtls1_get_record reads a new input record. On success, it places it in
- * |ssl->s3->rrec| and returns one. Otherwise it returns <= 0 on error or if
- * more data is needed. */
- static int dtls1_get_record(SSL *ssl) {
- again:
- /* Read a new packet if there is no unconsumed one. */
- if (ssl_read_buffer_len(ssl) == 0) {
- int ret = ssl_read_buffer_extend_to(ssl, 0 /* unused */);
- if (ret <= 0) {
- return ret;
- }
- }
- assert(ssl_read_buffer_len(ssl) > 0);
-
- /* Ensure the packet is large enough to decrypt in-place. */
- if (ssl_read_buffer_len(ssl) < ssl_record_prefix_len(ssl)) {
- ssl_read_buffer_clear(ssl);
- goto again;
- }
-
- uint8_t *out = ssl_read_buffer(ssl) + ssl_record_prefix_len(ssl);
- size_t max_out = ssl_read_buffer_len(ssl) - ssl_record_prefix_len(ssl);
- uint8_t type, alert;
- size_t len, consumed;
- switch (dtls_open_record(ssl, &type, out, &len, &consumed, &alert, max_out,
- ssl_read_buffer(ssl), ssl_read_buffer_len(ssl))) {
- case ssl_open_record_success:
- ssl_read_buffer_consume(ssl, consumed);
-
- if (len > 0xffff) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- return -1;
- }
-
- SSL3_RECORD *rr = &ssl->s3->rrec;
- rr->type = type;
- rr->length = (uint16_t)len;
- rr->data = out;
- return 1;
-
- case ssl_open_record_discard:
- ssl_read_buffer_consume(ssl, consumed);
- goto again;
-
- case ssl_open_record_error:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
- return -1;
-
- case ssl_open_record_partial:
- /* Impossible in DTLS. */
- break;
- }
-
- assert(0);
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek) {
- return dtls1_read_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf, len, peek);
- }
-
- int dtls1_read_change_cipher_spec(SSL *ssl) {
- uint8_t byte;
- int ret = dtls1_read_bytes(ssl, SSL3_RT_CHANGE_CIPHER_SPEC, &byte,
- 1 /* len */, 0 /* no peek */);
- if (ret <= 0) {
- return ret;
- }
- assert(ret == 1);
-
- if (ssl->s3->rrec.length != 0 || byte != 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;
- }
-
- if (ssl->msg_callback != NULL) {
- ssl->msg_callback(0, ssl->version, SSL3_RT_CHANGE_CIPHER_SPEC, &byte, 1,
- ssl, ssl->msg_callback_arg);
- }
-
- 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. */
- ssl->shutdown |= SSL_RECEIVED_SHUTDOWN;
- }
-
- /* Return up to 'len' payload bytes received in 'type' records.
- * 'type' is one of the following:
- *
- * - SSL3_RT_HANDSHAKE (when dtls1_get_message calls us)
- * - SSL3_RT_CHANGE_CIPHER_SPEC (when dtls1_read_change_cipher_spec calls us)
- * - SSL3_RT_APPLICATION_DATA (when dtls1_read_app_data calls us)
- *
- * If we don't have stored data to work from, read a DTLS record first (possibly
- * multiple records if we still don't have anything to return).
- *
- * This function must handle any surprises the peer may have for us, such as
- * Alert records (e.g. close_notify) and out of records. */
- int dtls1_read_bytes(SSL *ssl, int type, unsigned char *buf, int len, int peek) {
- int al, i, ret;
- unsigned int n;
- SSL3_RECORD *rr;
- void (*cb)(const SSL *ssl, int type, int value) = NULL;
-
- if ((type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE &&
- type != SSL3_RT_CHANGE_CIPHER_SPEC) ||
- (peek && type != SSL3_RT_APPLICATION_DATA)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- if (!ssl->in_handshake && SSL_in_init(ssl)) {
- /* type == SSL3_RT_APPLICATION_DATA */
- i = ssl->handshake_func(ssl);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
-
- start:
- ssl->rwstate = SSL_NOTHING;
-
- /* ssl->s3->rrec.type - is the type of record
- * ssl->s3->rrec.data - data
- * ssl->s3->rrec.off - offset into 'data' for next read
- * ssl->s3->rrec.length - number of bytes. */
- rr = &ssl->s3->rrec;
-
- /* Check for timeout */
- if (DTLSv1_handle_timeout(ssl) > 0) {
- goto start;
- }
-
- /* get new packet if necessary */
- if (rr->length == 0) {
- ret = dtls1_get_record(ssl);
- if (ret <= 0) {
- ret = dtls1_read_failed(ssl, ret);
- /* anything other than a timeout is an error */
- if (ret <= 0) {
- return ret;
- } else {
- goto start;
- }
- }
- }
-
- /* we now have a packet which can be read and processed */
-
- /* If the other end has shut down, throw anything we read away (even in
- * 'peek' mode) */
- if (ssl->shutdown & SSL_RECEIVED_SHUTDOWN) {
- rr->length = 0;
- ssl->rwstate = SSL_NOTHING;
- return 0;
- }
-
-
- if (type == rr->type) {
- /* Make sure that we are not getting application data when we
- * are doing a handshake for the first time. */
- if (SSL_in_init(ssl) && (type == SSL3_RT_APPLICATION_DATA) &&
- (ssl->s3->aead_read_ctx == NULL)) {
- /* TODO(davidben): Is this check redundant with the handshake_func
- * check? */
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_APP_DATA_IN_HANDSHAKE);
- goto f_err;
- }
-
- /* Discard empty records. */
- if (rr->length == 0) {
- goto start;
- }
-
- if (len <= 0) {
- return len;
- }
-
- if ((unsigned int)len > rr->length) {
- n = rr->length;
- } else {
- n = (unsigned int)len;
- }
-
- memcpy(buf, rr->data, n);
- if (!peek) {
- rr->length -= n;
- rr->data += n;
- if (rr->length == 0) {
- /* The record has been consumed, so we may now clear the buffer. */
- ssl_read_buffer_discard(ssl);
- }
- }
-
- return n;
- }
-
- /* If we get here, then type != rr->type. */
-
- /* If an alert record, process one alert out of the record. Note that we allow
- * a single record to contain multiple alerts. */
- if (rr->type == SSL3_RT_ALERT) {
- /* Alerts may not be fragmented. */
- if (rr->length < 2) {
- al = SSL_AD_DECODE_ERROR;
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_ALERT);
- goto f_err;
- }
-
- if (ssl->msg_callback) {
- ssl->msg_callback(0, ssl->version, SSL3_RT_ALERT, rr->data, 2, ssl,
- ssl->msg_callback_arg);
- }
- const uint8_t alert_level = rr->data[0];
- const uint8_t alert_descr = rr->data[1];
- rr->length -= 2;
- rr->data += 2;
-
- if (ssl->info_callback != NULL) {
- cb = ssl->info_callback;
- } else if (ssl->ctx->info_callback != NULL) {
- cb = ssl->ctx->info_callback;
- }
-
- if (cb != NULL) {
- uint16_t alert = (alert_level << 8) | alert_descr;
- cb(ssl, SSL_CB_READ_ALERT, alert);
- }
-
- if (alert_level == SSL3_AL_WARNING) {
- ssl->s3->warn_alert = alert_descr;
- if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
- ssl->shutdown |= SSL_RECEIVED_SHUTDOWN;
- return 0;
- }
- } else if (alert_level == SSL3_AL_FATAL) {
- char tmp[16];
-
- ssl->rwstate = SSL_NOTHING;
- ssl->s3->fatal_alert = alert_descr;
- OPENSSL_PUT_ERROR(SSL, SSL_AD_REASON_OFFSET + alert_descr);
- BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
- ERR_add_error_data(2, "SSL alert number ", tmp);
- ssl->shutdown |= SSL_RECEIVED_SHUTDOWN;
- SSL_CTX_remove_session(ssl->ctx, ssl->session);
- return 0;
- } else {
- al = SSL_AD_ILLEGAL_PARAMETER;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_ALERT_TYPE);
- goto f_err;
- }
-
- goto start;
- }
-
- /* Cross-epoch records are discarded, but we may receive out-of-order
- * application data between ChangeCipherSpec and Finished or a ChangeCipherSpec
- * before the appropriate point in the handshake. Those must be silently
- * discarded.
- *
- * However, only allow the out-of-order records in the correct epoch.
- * Application data must come in the encrypted epoch, and ChangeCipherSpec in
- * the unencrypted epoch (we never renegotiate). Other cases fall through and
- * fail with a fatal error. */
- if ((rr->type == SSL3_RT_APPLICATION_DATA &&
- ssl->s3->aead_read_ctx != NULL) ||
- (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC &&
- ssl->s3->aead_read_ctx == NULL)) {
- rr->length = 0;
- goto start;
- }
-
- if (rr->type == SSL3_RT_HANDSHAKE) {
- if (type != SSL3_RT_APPLICATION_DATA) {
- /* Out-of-order handshake record while looking for ChangeCipherSpec. Drop
- * it silently. */
- assert(type == SSL3_RT_CHANGE_CIPHER_SPEC);
- rr->length = 0;
- goto start;
- }
-
- /* 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. */
- if (rr->length < DTLS1_HM_HEADER_LENGTH) {
- al = SSL_AD_DECODE_ERROR;
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
- goto f_err;
- }
- struct hm_header_st msg_hdr;
- dtls1_get_message_header(rr->data, &msg_hdr);
-
- if (msg_hdr.type == SSL3_MT_FINISHED) {
- 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_buffered_messages(ssl);
- }
-
- rr->length = 0;
- goto start;
- }
-
- /* Otherwise, this is a pre-CCS handshake message from an unsupported
- * renegotiation attempt. Fall through to the error path. */
- }
-
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
-
- f_err:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
- return -1;
- }
-
- int dtls1_write_app_data(SSL *ssl, const void *buf_, int len) {
- int i;
-
- if (SSL_in_init(ssl) && !ssl->in_handshake) {
- i = ssl->handshake_func(ssl);
- if (i < 0) {
- return i;
- }
- if (i == 0) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_HANDSHAKE_FAILURE);
- return -1;
- }
- }
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_DTLS_MESSAGE_TOO_BIG);
- return -1;
- }
-
- i = dtls1_write_bytes(ssl, SSL3_RT_APPLICATION_DATA, buf_, len,
- dtls1_use_current_epoch);
- return i;
- }
-
- /* Call this to write data in records of type 'type' It will return <= 0 if not
- * all data has been sent or non-blocking IO. */
- int dtls1_write_bytes(SSL *ssl, int type, const void *buf, int len,
- enum dtls1_use_epoch_t use_epoch) {
- int i;
-
- assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
- ssl->rwstate = SSL_NOTHING;
- i = do_dtls1_write(ssl, type, buf, len, use_epoch);
- return i;
- }
-
- static int do_dtls1_write(SSL *ssl, int type, const uint8_t *buf,
- unsigned int len, enum dtls1_use_epoch_t use_epoch) {
- /* 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 we have an alert to send, lets send it */
- if (ssl->s3->alert_dispatch) {
- int ret = ssl->method->ssl_dispatch_alert(ssl);
- if (ret <= 0) {
- return ret;
- }
- /* if it went, fall through and send more stuff */
- }
-
- if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return -1;
- }
-
- if (len == 0) {
- return 0;
- }
-
- 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 (int)len;
- }
-
- int dtls1_dispatch_alert(SSL *ssl) {
- int i, j;
- void (*cb)(const SSL *ssl, int type, int value) = NULL;
- uint8_t buf[DTLS1_AL_HEADER_LENGTH];
- uint8_t *ptr = &buf[0];
-
- ssl->s3->alert_dispatch = 0;
-
- memset(buf, 0x00, sizeof(buf));
- *ptr++ = ssl->s3->send_alert[0];
- *ptr++ = ssl->s3->send_alert[1];
-
- i = do_dtls1_write(ssl, SSL3_RT_ALERT, &buf[0], sizeof(buf),
- dtls1_use_current_epoch);
- if (i <= 0) {
- ssl->s3->alert_dispatch = 1;
- } else {
- if (ssl->s3->send_alert[0] == SSL3_AL_FATAL) {
- (void)BIO_flush(ssl->wbio);
- }
-
- if (ssl->msg_callback) {
- ssl->msg_callback(1, ssl->version, SSL3_RT_ALERT, ssl->s3->send_alert, 2,
- ssl, ssl->msg_callback_arg);
- }
-
- if (ssl->info_callback != NULL) {
- cb = ssl->info_callback;
- } else if (ssl->ctx->info_callback != NULL) {
- cb = ssl->ctx->info_callback;
- }
-
- if (cb != NULL) {
- j = (ssl->s3->send_alert[0] << 8) | ssl->s3->send_alert[1];
- cb(ssl, SSL_CB_WRITE_ALERT, j);
- }
- }
-
- return i;
- }
|