|
- /*
- * 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 <limits.h>
- #include <string.h>
-
- #include <openssl/buf.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/mem.h>
- #include <openssl/rand.h>
- #include <openssl/type_check.h>
- #include <openssl/x509.h>
-
- #include "../crypto/internal.h"
- #include "internal.h"
-
-
- /* TODO(davidben): 28 comes from the size of IP + UDP header. Is this reasonable
- * for these values? Notably, why is kMinMTU a function of the transport
- * protocol's overhead rather than, say, what's needed to hold a minimally-sized
- * handshake fragment plus protocol overhead. */
-
- /* kMinMTU is the minimum acceptable MTU value. */
- static const unsigned int kMinMTU = 256 - 28;
-
- /* kDefaultMTU is the default MTU value to use if neither the user nor
- * the underlying BIO supplies one. */
- static const unsigned int kDefaultMTU = 1500 - 28;
-
-
- /* Receiving handshake messages. */
-
- static void dtls1_hm_fragment_free(hm_fragment *frag) {
- if (frag == NULL) {
- return;
- }
- OPENSSL_free(frag->data);
- OPENSSL_free(frag->reassembly);
- OPENSSL_free(frag);
- }
-
- static hm_fragment *dtls1_hm_fragment_new(const struct hm_header_st *msg_hdr) {
- hm_fragment *frag = OPENSSL_malloc(sizeof(hm_fragment));
- if (frag == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
- OPENSSL_memset(frag, 0, sizeof(hm_fragment));
- frag->type = msg_hdr->type;
- frag->seq = msg_hdr->seq;
- frag->msg_len = msg_hdr->msg_len;
-
- /* Allocate space for the reassembled message and fill in the header. */
- frag->data = OPENSSL_malloc(DTLS1_HM_HEADER_LENGTH + msg_hdr->msg_len);
- if (frag->data == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- CBB cbb;
- if (!CBB_init_fixed(&cbb, frag->data, DTLS1_HM_HEADER_LENGTH) ||
- !CBB_add_u8(&cbb, msg_hdr->type) ||
- !CBB_add_u24(&cbb, msg_hdr->msg_len) ||
- !CBB_add_u16(&cbb, msg_hdr->seq) ||
- !CBB_add_u24(&cbb, 0 /* frag_off */) ||
- !CBB_add_u24(&cbb, msg_hdr->msg_len) ||
- !CBB_finish(&cbb, NULL, NULL)) {
- CBB_cleanup(&cbb);
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- /* If the handshake message is empty, |frag->reassembly| is NULL. */
- if (msg_hdr->msg_len > 0) {
- /* Initialize reassembly bitmask. */
- if (msg_hdr->msg_len + 7 < msg_hdr->msg_len) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- goto err;
- }
- size_t bitmask_len = (msg_hdr->msg_len + 7) / 8;
- frag->reassembly = OPENSSL_malloc(bitmask_len);
- if (frag->reassembly == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
- OPENSSL_memset(frag->reassembly, 0, bitmask_len);
- }
-
- return frag;
-
- err:
- dtls1_hm_fragment_free(frag);
- return NULL;
- }
-
- /* bit_range returns a |uint8_t| with bits |start|, inclusive, to |end|,
- * exclusive, set. */
- static uint8_t bit_range(size_t start, size_t end) {
- return (uint8_t)(~((1u << start) - 1) & ((1u << end) - 1));
- }
-
- /* dtls1_hm_fragment_mark marks bytes |start|, inclusive, to |end|, exclusive,
- * as received in |frag|. If |frag| becomes complete, it clears
- * |frag->reassembly|. The range must be within the bounds of |frag|'s message
- * and |frag->reassembly| must not be NULL. */
- static void dtls1_hm_fragment_mark(hm_fragment *frag, size_t start,
- size_t end) {
- size_t msg_len = frag->msg_len;
-
- if (frag->reassembly == NULL || start > end || end > msg_len) {
- assert(0);
- return;
- }
- /* A zero-length message will never have a pending reassembly. */
- assert(msg_len > 0);
-
- if ((start >> 3) == (end >> 3)) {
- frag->reassembly[start >> 3] |= bit_range(start & 7, end & 7);
- } else {
- frag->reassembly[start >> 3] |= bit_range(start & 7, 8);
- for (size_t i = (start >> 3) + 1; i < (end >> 3); i++) {
- frag->reassembly[i] = 0xff;
- }
- if ((end & 7) != 0) {
- frag->reassembly[end >> 3] |= bit_range(0, end & 7);
- }
- }
-
- /* Check if the fragment is complete. */
- for (size_t i = 0; i < (msg_len >> 3); i++) {
- if (frag->reassembly[i] != 0xff) {
- return;
- }
- }
- if ((msg_len & 7) != 0 &&
- frag->reassembly[msg_len >> 3] != bit_range(0, msg_len & 7)) {
- return;
- }
-
- OPENSSL_free(frag->reassembly);
- frag->reassembly = NULL;
- }
-
- /* dtls1_is_current_message_complete returns one if the current handshake
- * message is complete and zero otherwise. */
- static int dtls1_is_current_message_complete(const SSL *ssl) {
- hm_fragment *frag = ssl->d1->incoming_messages[ssl->d1->handshake_read_seq %
- SSL_MAX_HANDSHAKE_FLIGHT];
- return frag != NULL && frag->reassembly == NULL;
- }
-
- /* dtls1_get_incoming_message returns the incoming message corresponding to
- * |msg_hdr|. If none exists, it creates a new one and inserts it in the
- * queue. Otherwise, it checks |msg_hdr| is consistent with the existing one. It
- * returns NULL on failure. The caller does not take ownership of the result. */
- static hm_fragment *dtls1_get_incoming_message(
- SSL *ssl, const struct hm_header_st *msg_hdr) {
- if (msg_hdr->seq < ssl->d1->handshake_read_seq ||
- msg_hdr->seq - ssl->d1->handshake_read_seq >= SSL_MAX_HANDSHAKE_FLIGHT) {
- return NULL;
- }
-
- size_t idx = msg_hdr->seq % SSL_MAX_HANDSHAKE_FLIGHT;
- hm_fragment *frag = ssl->d1->incoming_messages[idx];
- if (frag != NULL) {
- assert(frag->seq == msg_hdr->seq);
- /* The new fragment must be compatible with the previous fragments from this
- * message. */
- if (frag->type != msg_hdr->type ||
- frag->msg_len != msg_hdr->msg_len) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_FRAGMENT_MISMATCH);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return NULL;
- }
- return frag;
- }
-
- /* This is the first fragment from this message. */
- frag = dtls1_hm_fragment_new(msg_hdr);
- if (frag == NULL) {
- return NULL;
- }
- ssl->d1->incoming_messages[idx] = frag;
- return frag;
- }
-
- /* dtls1_process_handshake_record reads a handshake record and processes it. It
- * returns one if the record was successfully processed and 0 or -1 on error. */
- static int dtls1_process_handshake_record(SSL *ssl) {
- SSL3_RECORD *rr = &ssl->s3->rrec;
-
- start:
- if (rr->length == 0) {
- int ret = dtls1_get_record(ssl);
- if (ret <= 0) {
- return ret;
- }
- }
-
- /* 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) {
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
- return -1;
- }
-
- CBS cbs;
- CBS_init(&cbs, rr->data, rr->length);
-
- while (CBS_len(&cbs) > 0) {
- /* Read a handshake fragment. */
- struct hm_header_st msg_hdr;
- CBS body;
- if (!dtls1_parse_fragment(&cbs, &msg_hdr, &body)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_HANDSHAKE_RECORD);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
- return -1;
- }
-
- const size_t frag_off = msg_hdr.frag_off;
- const size_t frag_len = msg_hdr.frag_len;
- const size_t msg_len = msg_hdr.msg_len;
- if (frag_off > msg_len || frag_off + frag_len < frag_off ||
- frag_off + frag_len > msg_len ||
- msg_len > ssl_max_handshake_message_len(ssl)) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_EXCESSIVE_MESSAGE_SIZE);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return -1;
- }
-
- /* The encrypted epoch in DTLS has only one handshake message. */
- if (ssl->d1->r_epoch == 1 && msg_hdr.seq != ssl->d1->handshake_read_seq) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_RECORD);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- return -1;
- }
-
- if (msg_hdr.seq < ssl->d1->handshake_read_seq ||
- msg_hdr.seq >
- (unsigned)ssl->d1->handshake_read_seq + SSL_MAX_HANDSHAKE_FLIGHT) {
- /* Ignore fragments from the past, or ones too far in the future. */
- continue;
- }
-
- hm_fragment *frag = dtls1_get_incoming_message(ssl, &msg_hdr);
- if (frag == NULL) {
- return -1;
- }
- assert(frag->msg_len == msg_len);
-
- if (frag->reassembly == NULL) {
- /* The message is already assembled. */
- continue;
- }
- assert(msg_len > 0);
-
- /* Copy the body into the fragment. */
- OPENSSL_memcpy(frag->data + DTLS1_HM_HEADER_LENGTH + frag_off,
- CBS_data(&body), CBS_len(&body));
- dtls1_hm_fragment_mark(frag, frag_off, frag_off + frag_len);
- }
-
- rr->length = 0;
- ssl_read_buffer_discard(ssl);
- return 1;
- }
-
- int dtls1_get_message(SSL *ssl) {
- if (ssl->s3->tmp.reuse_message) {
- /* There must be a current message. */
- assert(ssl->init_msg != NULL);
- ssl->s3->tmp.reuse_message = 0;
- } else {
- dtls1_release_current_message(ssl, 0 /* don't free buffer */);
- }
-
- /* Process handshake records until the current message is ready. */
- while (!dtls1_is_current_message_complete(ssl)) {
- int ret = dtls1_process_handshake_record(ssl);
- if (ret <= 0) {
- return ret;
- }
- }
-
- hm_fragment *frag = ssl->d1->incoming_messages[ssl->d1->handshake_read_seq %
- SSL_MAX_HANDSHAKE_FLIGHT];
- assert(frag != NULL);
- assert(frag->reassembly == NULL);
- assert(ssl->d1->handshake_read_seq == frag->seq);
-
- /* TODO(davidben): This function has a lot of implicit outputs. Simplify the
- * |ssl_get_message| API. */
- ssl->s3->tmp.message_type = frag->type;
- ssl->init_msg = frag->data + DTLS1_HM_HEADER_LENGTH;
- ssl->init_num = frag->msg_len;
-
- ssl_do_msg_callback(ssl, 0 /* read */, SSL3_RT_HANDSHAKE, frag->data,
- ssl->init_num + DTLS1_HM_HEADER_LENGTH);
- return 1;
- }
-
- void dtls1_get_current_message(const SSL *ssl, CBS *out) {
- assert(dtls1_is_current_message_complete(ssl));
-
- hm_fragment *frag = ssl->d1->incoming_messages[ssl->d1->handshake_read_seq %
- SSL_MAX_HANDSHAKE_FLIGHT];
- CBS_init(out, frag->data, DTLS1_HM_HEADER_LENGTH + frag->msg_len);
- }
-
- void dtls1_release_current_message(SSL *ssl, int free_buffer) {
- if (ssl->init_msg == NULL) {
- return;
- }
-
- assert(dtls1_is_current_message_complete(ssl));
- size_t index = ssl->d1->handshake_read_seq % SSL_MAX_HANDSHAKE_FLIGHT;
- dtls1_hm_fragment_free(ssl->d1->incoming_messages[index]);
- ssl->d1->incoming_messages[index] = NULL;
- ssl->d1->handshake_read_seq++;
-
- ssl->init_msg = NULL;
- ssl->init_num = 0;
- }
-
- void dtls_clear_incoming_messages(SSL *ssl) {
- for (size_t i = 0; i < SSL_MAX_HANDSHAKE_FLIGHT; i++) {
- dtls1_hm_fragment_free(ssl->d1->incoming_messages[i]);
- ssl->d1->incoming_messages[i] = NULL;
- }
- }
-
- int dtls_has_incoming_messages(const SSL *ssl) {
- size_t current = ssl->d1->handshake_read_seq % SSL_MAX_HANDSHAKE_FLIGHT;
- for (size_t i = 0; i < SSL_MAX_HANDSHAKE_FLIGHT; i++) {
- /* Skip the current message. */
- if (ssl->init_msg != NULL && i == current) {
- assert(dtls1_is_current_message_complete(ssl));
- continue;
- }
- if (ssl->d1->incoming_messages[i] != NULL) {
- return 1;
- }
- }
- return 0;
- }
-
- int dtls1_parse_fragment(CBS *cbs, struct hm_header_st *out_hdr,
- CBS *out_body) {
- OPENSSL_memset(out_hdr, 0x00, sizeof(struct hm_header_st));
-
- if (!CBS_get_u8(cbs, &out_hdr->type) ||
- !CBS_get_u24(cbs, &out_hdr->msg_len) ||
- !CBS_get_u16(cbs, &out_hdr->seq) ||
- !CBS_get_u24(cbs, &out_hdr->frag_off) ||
- !CBS_get_u24(cbs, &out_hdr->frag_len) ||
- !CBS_get_bytes(cbs, out_body, out_hdr->frag_len)) {
- return 0;
- }
-
- return 1;
- }
-
-
- /* Sending handshake messages. */
-
- void dtls_clear_outgoing_messages(SSL *ssl) {
- for (size_t i = 0; i < ssl->d1->outgoing_messages_len; i++) {
- OPENSSL_free(ssl->d1->outgoing_messages[i].data);
- ssl->d1->outgoing_messages[i].data = NULL;
- }
- ssl->d1->outgoing_messages_len = 0;
- ssl->d1->outgoing_written = 0;
- ssl->d1->outgoing_offset = 0;
- }
-
- int dtls1_init_message(SSL *ssl, CBB *cbb, CBB *body, uint8_t type) {
- /* Pick a modest size hint to save most of the |realloc| calls. */
- if (!CBB_init(cbb, 64) ||
- !CBB_add_u8(cbb, type) ||
- !CBB_add_u24(cbb, 0 /* length (filled in later) */) ||
- !CBB_add_u16(cbb, ssl->d1->handshake_write_seq) ||
- !CBB_add_u24(cbb, 0 /* offset */) ||
- !CBB_add_u24_length_prefixed(cbb, body)) {
- return 0;
- }
-
- return 1;
- }
-
- int dtls1_finish_message(SSL *ssl, CBB *cbb, uint8_t **out_msg,
- size_t *out_len) {
- *out_msg = NULL;
- if (!CBB_finish(cbb, out_msg, out_len) ||
- *out_len < DTLS1_HM_HEADER_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- OPENSSL_free(*out_msg);
- return 0;
- }
-
- /* Fix up the header. Copy the fragment length into the total message
- * length. */
- OPENSSL_memcpy(*out_msg + 1, *out_msg + DTLS1_HM_HEADER_LENGTH - 3, 3);
- return 1;
- }
-
- /* add_outgoing adds a new handshake message or ChangeCipherSpec to the current
- * outgoing flight. It returns one on success and zero on error. In both cases,
- * it takes ownership of |data| and releases it with |OPENSSL_free| when
- * done. */
- static int add_outgoing(SSL *ssl, int is_ccs, uint8_t *data, size_t len) {
- OPENSSL_COMPILE_ASSERT(SSL_MAX_HANDSHAKE_FLIGHT <
- (1 << 8 * sizeof(ssl->d1->outgoing_messages_len)),
- outgoing_messages_len_is_too_small);
- if (ssl->d1->outgoing_messages_len >= SSL_MAX_HANDSHAKE_FLIGHT) {
- assert(0);
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- OPENSSL_free(data);
- return 0;
- }
-
- if (!is_ccs) {
- /* TODO(svaldez): Move this up a layer to fix abstraction for SSL_TRANSCRIPT
- * on hs. */
- if (ssl->s3->hs != NULL &&
- !SSL_TRANSCRIPT_update(&ssl->s3->hs->transcript, data, len)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- OPENSSL_free(data);
- return 0;
- }
- ssl->d1->handshake_write_seq++;
- }
-
- DTLS_OUTGOING_MESSAGE *msg =
- &ssl->d1->outgoing_messages[ssl->d1->outgoing_messages_len];
- msg->data = data;
- msg->len = len;
- msg->epoch = ssl->d1->w_epoch;
- msg->is_ccs = is_ccs;
-
- ssl->d1->outgoing_messages_len++;
- return 1;
- }
-
- int dtls1_add_message(SSL *ssl, uint8_t *data, size_t len) {
- return add_outgoing(ssl, 0 /* handshake */, data, len);
- }
-
- int dtls1_add_change_cipher_spec(SSL *ssl) {
- return add_outgoing(ssl, 1 /* ChangeCipherSpec */, NULL, 0);
- }
-
- int dtls1_add_alert(SSL *ssl, uint8_t level, uint8_t desc) {
- /* The |add_alert| path is only used for warning alerts for now, which DTLS
- * never sends. This will be implemented later once closure alerts are
- * converted. */
- assert(0);
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return 0;
- }
-
- /* dtls1_update_mtu updates the current MTU from the BIO, ensuring it is above
- * the minimum. */
- static void dtls1_update_mtu(SSL *ssl) {
- /* TODO(davidben): No consumer implements |BIO_CTRL_DGRAM_SET_MTU| and the
- * only |BIO_CTRL_DGRAM_QUERY_MTU| implementation could use
- * |SSL_set_mtu|. Does this need to be so complex? */
- if (ssl->d1->mtu < dtls1_min_mtu() &&
- !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
- long mtu = BIO_ctrl(ssl->wbio, BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
- if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) {
- ssl->d1->mtu = (unsigned)mtu;
- } else {
- ssl->d1->mtu = kDefaultMTU;
- BIO_ctrl(ssl->wbio, BIO_CTRL_DGRAM_SET_MTU, ssl->d1->mtu, NULL);
- }
- }
-
- /* The MTU should be above the minimum now. */
- assert(ssl->d1->mtu >= dtls1_min_mtu());
- }
-
- enum seal_result_t {
- seal_error,
- seal_no_progress,
- seal_partial,
- seal_success,
- };
-
- /* seal_next_message seals |msg|, which must be the next message, to |out|. If
- * progress was made, it returns |seal_partial| or |seal_success| and sets
- * |*out_len| to the number of bytes written. */
- static enum seal_result_t seal_next_message(SSL *ssl, uint8_t *out,
- size_t *out_len, size_t max_out,
- const DTLS_OUTGOING_MESSAGE *msg) {
- assert(ssl->d1->outgoing_written < ssl->d1->outgoing_messages_len);
- assert(msg == &ssl->d1->outgoing_messages[ssl->d1->outgoing_written]);
-
- /* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1
- * (negotiated cipher) exist. */
- assert(ssl->d1->w_epoch == 0 || ssl->d1->w_epoch == 1);
- assert(msg->epoch <= ssl->d1->w_epoch);
- enum dtls1_use_epoch_t use_epoch = dtls1_use_current_epoch;
- if (ssl->d1->w_epoch == 1 && msg->epoch == 0) {
- use_epoch = dtls1_use_previous_epoch;
- }
- size_t overhead = dtls_max_seal_overhead(ssl, use_epoch);
- size_t prefix = dtls_seal_prefix_len(ssl, use_epoch);
-
- if (msg->is_ccs) {
- /* Check there is room for the ChangeCipherSpec. */
- static const uint8_t kChangeCipherSpec[1] = {SSL3_MT_CCS};
- if (max_out < sizeof(kChangeCipherSpec) + overhead) {
- return seal_no_progress;
- }
-
- if (!dtls_seal_record(ssl, out, out_len, max_out,
- SSL3_RT_CHANGE_CIPHER_SPEC, kChangeCipherSpec,
- sizeof(kChangeCipherSpec), use_epoch)) {
- return seal_error;
- }
-
- ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_CHANGE_CIPHER_SPEC,
- kChangeCipherSpec, sizeof(kChangeCipherSpec));
- return seal_success;
- }
-
- /* DTLS messages are serialized as a single fragment in |msg|. */
- CBS cbs, body;
- struct hm_header_st hdr;
- CBS_init(&cbs, msg->data, msg->len);
- if (!dtls1_parse_fragment(&cbs, &hdr, &body) ||
- hdr.frag_off != 0 ||
- hdr.frag_len != CBS_len(&body) ||
- hdr.msg_len != CBS_len(&body) ||
- !CBS_skip(&body, ssl->d1->outgoing_offset) ||
- CBS_len(&cbs) != 0) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return seal_error;
- }
-
- /* Determine how much progress can be made. */
- if (max_out < DTLS1_HM_HEADER_LENGTH + 1 + overhead || max_out < prefix) {
- return seal_no_progress;
- }
- size_t todo = CBS_len(&body);
- if (todo > max_out - DTLS1_HM_HEADER_LENGTH - overhead) {
- todo = max_out - DTLS1_HM_HEADER_LENGTH - overhead;
- }
-
- /* Assemble a fragment, to be sealed in-place. */
- CBB cbb;
- uint8_t *frag = out + prefix;
- size_t max_frag = max_out - prefix, frag_len;
- if (!CBB_init_fixed(&cbb, frag, max_frag) ||
- !CBB_add_u8(&cbb, hdr.type) ||
- !CBB_add_u24(&cbb, hdr.msg_len) ||
- !CBB_add_u16(&cbb, hdr.seq) ||
- !CBB_add_u24(&cbb, ssl->d1->outgoing_offset) ||
- !CBB_add_u24(&cbb, todo) ||
- !CBB_add_bytes(&cbb, CBS_data(&body), todo) ||
- !CBB_finish(&cbb, NULL, &frag_len)) {
- CBB_cleanup(&cbb);
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- return seal_error;
- }
-
- ssl_do_msg_callback(ssl, 1 /* write */, SSL3_RT_HANDSHAKE, frag, frag_len);
-
- if (!dtls_seal_record(ssl, out, out_len, max_out, SSL3_RT_HANDSHAKE,
- out + prefix, frag_len, use_epoch)) {
- return seal_error;
- }
-
- if (todo == CBS_len(&body)) {
- /* The next message is complete. */
- ssl->d1->outgoing_offset = 0;
- return seal_success;
- }
-
- ssl->d1->outgoing_offset += todo;
- return seal_partial;
- }
-
- /* seal_next_packet writes as much of the next flight as possible to |out| and
- * advances |ssl->d1->outgoing_written| and |ssl->d1->outgoing_offset| as
- * appropriate. */
- static int seal_next_packet(SSL *ssl, uint8_t *out, size_t *out_len,
- size_t max_out) {
- int made_progress = 0;
- size_t total = 0;
- assert(ssl->d1->outgoing_written < ssl->d1->outgoing_messages_len);
- for (; ssl->d1->outgoing_written < ssl->d1->outgoing_messages_len;
- ssl->d1->outgoing_written++) {
- const DTLS_OUTGOING_MESSAGE *msg =
- &ssl->d1->outgoing_messages[ssl->d1->outgoing_written];
- size_t len;
- enum seal_result_t ret = seal_next_message(ssl, out, &len, max_out, msg);
- switch (ret) {
- case seal_error:
- return 0;
-
- case seal_no_progress:
- goto packet_full;
-
- case seal_partial:
- case seal_success:
- out += len;
- max_out -= len;
- total += len;
- made_progress = 1;
-
- if (ret == seal_partial) {
- goto packet_full;
- }
- break;
- }
- }
-
- packet_full:
- /* The MTU was too small to make any progress. */
- if (!made_progress) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_MTU_TOO_SMALL);
- return 0;
- }
-
- *out_len = total;
- return 1;
- }
-
- int dtls1_flush_flight(SSL *ssl) {
- dtls1_update_mtu(ssl);
-
- int ret = -1;
- uint8_t *packet = OPENSSL_malloc(ssl->d1->mtu);
- if (packet == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- while (ssl->d1->outgoing_written < ssl->d1->outgoing_messages_len) {
- uint8_t old_written = ssl->d1->outgoing_written;
- uint32_t old_offset = ssl->d1->outgoing_offset;
-
- size_t packet_len;
- if (!seal_next_packet(ssl, packet, &packet_len, ssl->d1->mtu)) {
- goto err;
- }
-
- int bio_ret = BIO_write(ssl->wbio, packet, packet_len);
- if (bio_ret <= 0) {
- /* Retry this packet the next time around. */
- ssl->d1->outgoing_written = old_written;
- ssl->d1->outgoing_offset = old_offset;
- ssl->rwstate = SSL_WRITING;
- ret = bio_ret;
- goto err;
- }
- }
-
- if (BIO_flush(ssl->wbio) <= 0) {
- ssl->rwstate = SSL_WRITING;
- goto err;
- }
-
- ret = 1;
-
- err:
- OPENSSL_free(packet);
- return ret;
- }
-
- int dtls1_retransmit_outgoing_messages(SSL *ssl) {
- /* Rewind to the start of the flight and write it again.
- *
- * TODO(davidben): This does not allow retransmits to be resumed on
- * non-blocking write. */
- ssl->d1->outgoing_written = 0;
- ssl->d1->outgoing_offset = 0;
-
- return dtls1_flush_flight(ssl);
- }
-
- unsigned int dtls1_min_mtu(void) {
- return kMinMTU;
- }
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