|
- /*
- * 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/x509.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;
-
- /* kMaxHandshakeBuffer is the maximum number of handshake messages ahead of the
- * current one to buffer. */
- static const unsigned int kHandshakeBufferSize = 10;
-
- static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly) {
- hm_fragment *frag = OPENSSL_malloc(sizeof(hm_fragment));
- if (frag == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
- memset(frag, 0, sizeof(hm_fragment));
-
- /* If the handshake message is empty, |frag->fragment| and |frag->reassembly|
- * are NULL. */
- if (frag_len > 0) {
- frag->fragment = OPENSSL_malloc(frag_len);
- if (frag->fragment == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- if (reassembly) {
- /* Initialize reassembly bitmask. */
- if (frag_len + 7 < frag_len) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
- goto err;
- }
- size_t bitmask_len = (frag_len + 7) / 8;
- frag->reassembly = OPENSSL_malloc(bitmask_len);
- if (frag->reassembly == NULL) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
- memset(frag->reassembly, 0, bitmask_len);
- }
- }
-
- return frag;
-
- err:
- dtls1_hm_fragment_free(frag);
- return NULL;
- }
-
- void dtls1_hm_fragment_free(hm_fragment *frag) {
- if (frag == NULL) {
- return;
- }
- OPENSSL_free(frag->fragment);
- OPENSSL_free(frag->reassembly);
- OPENSSL_free(frag);
- }
-
- #if !defined(inline)
- #define inline __inline
- #endif
-
- /* bit_range returns a |uint8_t| with bits |start|, inclusive, to |end|,
- * exclusive, set. */
- static inline 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 i;
- size_t msg_len = frag->msg_header.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 (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 (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;
- }
-
- static void dtls1_update_mtu(SSL *ssl) {
- /* TODO(davidben): What is this code doing and do we need it? */
- 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());
- }
-
- /* dtls1_max_record_size returns the maximum record body length that may be
- * written without exceeding the MTU. It accounts for any buffering installed on
- * the write BIO. If no record may be written, it returns zero. */
- static size_t dtls1_max_record_size(SSL *ssl) {
- size_t ret = ssl->d1->mtu;
-
- size_t overhead = ssl_max_seal_overhead(ssl);
- if (ret <= overhead) {
- return 0;
- }
- ret -= overhead;
-
- size_t pending = BIO_wpending(ssl->wbio);
- if (ret <= pending) {
- return 0;
- }
- ret -= pending;
-
- return ret;
- }
-
- static int dtls1_write_change_cipher_spec(SSL *ssl,
- enum dtls1_use_epoch_t use_epoch) {
- dtls1_update_mtu(ssl);
-
- /* During the handshake, wbio is buffered to pack messages together. Flush the
- * buffer if the ChangeCipherSpec would not fit in a packet. */
- if (dtls1_max_record_size(ssl) == 0) {
- int ret = BIO_flush(ssl->wbio);
- if (ret <= 0) {
- ssl->rwstate = SSL_WRITING;
- return ret;
- }
- }
-
- static const uint8_t kChangeCipherSpec[1] = {SSL3_MT_CCS};
- int ret =
- dtls1_write_record(ssl, SSL3_RT_CHANGE_CIPHER_SPEC, kChangeCipherSpec,
- sizeof(kChangeCipherSpec), use_epoch);
- if (ret <= 0) {
- return ret;
- }
-
- ssl_do_msg_callback(ssl, 1 /* write */, ssl->version,
- SSL3_RT_CHANGE_CIPHER_SPEC, kChangeCipherSpec,
- sizeof(kChangeCipherSpec));
- return 1;
- }
-
- int dtls1_do_handshake_write(SSL *ssl, enum dtls1_use_epoch_t use_epoch) {
- dtls1_update_mtu(ssl);
-
- int ret = -1;
- CBB cbb;
- CBB_zero(&cbb);
- /* Allocate a temporary buffer to hold the message fragments to avoid
- * clobbering the message. */
- uint8_t *buf = OPENSSL_malloc(ssl->d1->mtu);
- if (buf == NULL) {
- goto err;
- }
-
- /* Consume the message header. Fragments will have different headers
- * prepended. */
- if (ssl->init_off == 0) {
- ssl->init_off += DTLS1_HM_HEADER_LENGTH;
- ssl->init_num -= DTLS1_HM_HEADER_LENGTH;
- }
- assert(ssl->init_off >= DTLS1_HM_HEADER_LENGTH);
-
- do {
- /* During the handshake, wbio is buffered to pack messages together. Flush
- * the buffer if there isn't enough room to make progress. */
- if (dtls1_max_record_size(ssl) < DTLS1_HM_HEADER_LENGTH + 1) {
- int flush_ret = BIO_flush(ssl->wbio);
- if (flush_ret <= 0) {
- ssl->rwstate = SSL_WRITING;
- ret = flush_ret;
- goto err;
- }
- assert(BIO_wpending(ssl->wbio) == 0);
- }
-
- size_t todo = dtls1_max_record_size(ssl);
- if (todo < DTLS1_HM_HEADER_LENGTH + 1) {
- /* To make forward progress, the MTU must, at minimum, fit the handshake
- * header and one byte of handshake body. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_MTU_TOO_SMALL);
- goto err;
- }
- todo -= DTLS1_HM_HEADER_LENGTH;
-
- if (todo > (size_t)ssl->init_num) {
- todo = ssl->init_num;
- }
- if (todo >= (1u << 24)) {
- todo = (1u << 24) - 1;
- }
-
- size_t len;
- if (!CBB_init_fixed(&cbb, buf, ssl->d1->mtu) ||
- !CBB_add_u8(&cbb, ssl->d1->w_msg_hdr.type) ||
- !CBB_add_u24(&cbb, ssl->d1->w_msg_hdr.msg_len) ||
- !CBB_add_u16(&cbb, ssl->d1->w_msg_hdr.seq) ||
- !CBB_add_u24(&cbb, ssl->init_off - DTLS1_HM_HEADER_LENGTH) ||
- !CBB_add_u24(&cbb, todo) ||
- !CBB_add_bytes(
- &cbb, (const uint8_t *)ssl->init_buf->data + ssl->init_off, todo) ||
- !CBB_finish(&cbb, NULL, &len)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- goto err;
- }
-
- int write_ret =
- dtls1_write_record(ssl, SSL3_RT_HANDSHAKE, buf, len, use_epoch);
- if (write_ret <= 0) {
- ret = write_ret;
- goto err;
- }
- ssl->init_off += todo;
- ssl->init_num -= todo;
- } while (ssl->init_num > 0);
-
- ssl_do_msg_callback(ssl, 1 /* write */, ssl->version, SSL3_RT_HANDSHAKE,
- ssl->init_buf->data,
- (size_t)(ssl->init_off + ssl->init_num));
-
- ssl->init_off = 0;
- ssl->init_num = 0;
-
- ret = 1;
-
- err:
- CBB_cleanup(&cbb);
- OPENSSL_free(buf);
- return ret;
- }
-
- /* dtls1_is_next_message_complete returns one if the next handshake message is
- * complete and zero otherwise. */
- static int dtls1_is_next_message_complete(SSL *ssl) {
- pitem *item = pqueue_peek(ssl->d1->buffered_messages);
- if (item == NULL) {
- return 0;
- }
-
- hm_fragment *frag = (hm_fragment *)item->data;
- assert(ssl->d1->handshake_read_seq <= frag->msg_header.seq);
-
- return ssl->d1->handshake_read_seq == frag->msg_header.seq &&
- frag->reassembly == NULL;
- }
-
- /* dtls1_get_buffered_message returns the buffered 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_buffered_message(
- SSL *ssl, const struct hm_header_st *msg_hdr) {
- uint8_t seq64be[8];
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(msg_hdr->seq >> 8);
- seq64be[7] = (uint8_t)msg_hdr->seq;
- pitem *item = pqueue_find(ssl->d1->buffered_messages, seq64be);
-
- hm_fragment *frag;
- if (item == NULL) {
- /* This is the first fragment from this message. */
- frag = dtls1_hm_fragment_new(msg_hdr->msg_len,
- 1 /* reassembly buffer needed */);
- if (frag == NULL) {
- return NULL;
- }
- memcpy(&frag->msg_header, msg_hdr, sizeof(*msg_hdr));
- item = pitem_new(seq64be, frag);
- if (item == NULL) {
- dtls1_hm_fragment_free(frag);
- return NULL;
- }
- item = pqueue_insert(ssl->d1->buffered_messages, item);
- /* |pqueue_insert| fails iff a duplicate item is inserted, but |item| cannot
- * be a duplicate. */
- assert(item != NULL);
- } else {
- frag = item->data;
- assert(frag->msg_header.seq == msg_hdr->seq);
- if (frag->msg_header.type != msg_hdr->type ||
- frag->msg_header.msg_len != msg_hdr->msg_len) {
- /* The new fragment must be compatible with the previous fragments from
- * this message. */
- OPENSSL_PUT_ERROR(SSL, SSL_R_FRAGMENT_MISMATCH);
- ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return NULL;
- }
- }
- 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;
- }
-
- if (msg_hdr.seq < ssl->d1->handshake_read_seq ||
- msg_hdr.seq >
- (unsigned)ssl->d1->handshake_read_seq + kHandshakeBufferSize) {
- /* Ignore fragments from the past, or ones too far in the future. */
- continue;
- }
-
- hm_fragment *frag = dtls1_get_buffered_message(ssl, &msg_hdr);
- if (frag == NULL) {
- return -1;
- }
- assert(frag->msg_header.msg_len == msg_len);
-
- if (frag->reassembly == NULL) {
- /* The message is already assembled. */
- continue;
- }
- assert(msg_len > 0);
-
- /* Copy the body into the fragment. */
- memcpy(frag->fragment + 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;
- }
-
- /* dtls1_get_message reads a handshake message of message type |msg_type| (any
- * if |msg_type| == -1). Read an entire handshake message. Handshake messages
- * arrive in fragments. */
- long dtls1_get_message(SSL *ssl, int msg_type,
- enum ssl_hash_message_t hash_message, int *ok) {
- pitem *item = NULL;
- hm_fragment *frag = NULL;
- int al;
-
- /* s3->tmp is used to store messages that are unexpected, caused
- * by the absence of an optional handshake message */
- if (ssl->s3->tmp.reuse_message) {
- /* A ssl_dont_hash_message call cannot be combined with reuse_message; the
- * ssl_dont_hash_message would have to have been applied to the previous
- * call. */
- assert(hash_message == ssl_hash_message);
- ssl->s3->tmp.reuse_message = 0;
- if (msg_type >= 0 && ssl->s3->tmp.message_type != msg_type) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- *ok = 1;
- assert(ssl->init_buf->length >= DTLS1_HM_HEADER_LENGTH);
- ssl->init_msg = (uint8_t *)ssl->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- ssl->init_num = (int)ssl->init_buf->length - DTLS1_HM_HEADER_LENGTH;
- return ssl->init_num;
- }
-
- /* Process handshake records until the next message is ready. */
- while (!dtls1_is_next_message_complete(ssl)) {
- int ret = dtls1_process_handshake_record(ssl);
- if (ret <= 0) {
- *ok = 0;
- return ret;
- }
- }
-
- /* Read out the next complete handshake message. */
- item = pqueue_pop(ssl->d1->buffered_messages);
- assert(item != NULL);
- frag = (hm_fragment *)item->data;
- assert(ssl->d1->handshake_read_seq == frag->msg_header.seq);
- assert(frag->reassembly == NULL);
-
- /* Reconstruct the assembled message. */
- CBB cbb;
- CBB_zero(&cbb);
- if (!BUF_MEM_reserve(ssl->init_buf, (size_t)frag->msg_header.msg_len +
- DTLS1_HM_HEADER_LENGTH) ||
- !CBB_init_fixed(&cbb, (uint8_t *)ssl->init_buf->data,
- ssl->init_buf->max) ||
- !CBB_add_u8(&cbb, frag->msg_header.type) ||
- !CBB_add_u24(&cbb, frag->msg_header.msg_len) ||
- !CBB_add_u16(&cbb, frag->msg_header.seq) ||
- !CBB_add_u24(&cbb, 0 /* frag_off */) ||
- !CBB_add_u24(&cbb, frag->msg_header.msg_len) ||
- !CBB_add_bytes(&cbb, frag->fragment, frag->msg_header.msg_len) ||
- !CBB_finish(&cbb, NULL, &ssl->init_buf->length)) {
- CBB_cleanup(&cbb);
- OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
- goto err;
- }
- assert(ssl->init_buf->length ==
- (size_t)frag->msg_header.msg_len + DTLS1_HM_HEADER_LENGTH);
-
- ssl->d1->handshake_read_seq++;
-
- /* TODO(davidben): This function has a lot of implicit outputs. Simplify the
- * |ssl_get_message| API. */
- ssl->s3->tmp.message_type = frag->msg_header.type;
- ssl->init_msg = (uint8_t *)ssl->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- ssl->init_num = frag->msg_header.msg_len;
-
- if (msg_type >= 0 && ssl->s3->tmp.message_type != msg_type) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- if (hash_message == ssl_hash_message && !ssl3_hash_current_message(ssl)) {
- goto err;
- }
-
- ssl_do_msg_callback(ssl, 0 /* read */, ssl->version, SSL3_RT_HANDSHAKE,
- ssl->init_buf->data,
- ssl->init_num + DTLS1_HM_HEADER_LENGTH);
-
- pitem_free(item);
- dtls1_hm_fragment_free(frag);
-
- *ok = 1;
- return ssl->init_num;
-
- f_err:
- ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
- err:
- pitem_free(item);
- dtls1_hm_fragment_free(frag);
- *ok = 0;
- return -1;
- }
-
- static uint16_t dtls1_get_queue_priority(uint16_t seq, int is_ccs) {
- assert(seq * 2 >= seq);
-
- /* The index of the retransmission queue actually is the message sequence
- * number, since the queue only contains messages of a single handshake.
- * However, the ChangeCipherSpec has no message sequence number and so using
- * only the sequence will result in the CCS and Finished having the same
- * index. To prevent this, the sequence number is multiplied by 2. In case of
- * a CCS 1 is subtracted. This does not only differ CSS and Finished, it also
- * maintains the order of the index (important for priority queues) and fits
- * in the unsigned short variable. */
- return seq * 2 - is_ccs;
- }
-
- static int dtls1_retransmit_message(SSL *ssl, hm_fragment *frag) {
- /* 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(frag->msg_header.epoch <= ssl->d1->w_epoch);
- enum dtls1_use_epoch_t use_epoch = dtls1_use_current_epoch;
- if (ssl->d1->w_epoch == 1 && frag->msg_header.epoch == 0) {
- use_epoch = dtls1_use_previous_epoch;
- }
-
- /* TODO(davidben): This cannot handle non-blocking writes. */
- int ret;
- if (frag->msg_header.is_ccs) {
- ret = dtls1_write_change_cipher_spec(ssl, use_epoch);
- } else {
- /* Restore the message body.
- * TODO(davidben): Make this less stateful. */
- memcpy(ssl->init_buf->data, frag->fragment,
- frag->msg_header.msg_len + DTLS1_HM_HEADER_LENGTH);
- ssl->init_num = frag->msg_header.msg_len + DTLS1_HM_HEADER_LENGTH;
-
- dtls1_set_message_header(ssl, frag->msg_header.type,
- frag->msg_header.msg_len, frag->msg_header.seq,
- 0, frag->msg_header.frag_len);
- ret = dtls1_do_handshake_write(ssl, use_epoch);
- }
-
- return ret;
- }
-
- int dtls1_retransmit_buffered_messages(SSL *ssl) {
- /* Ensure we are packing handshake messages. */
- const int was_buffered = ssl_is_wbio_buffered(ssl);
- assert(was_buffered == SSL_in_init(ssl));
- if (!was_buffered && !ssl_init_wbio_buffer(ssl)) {
- return -1;
- }
- assert(ssl_is_wbio_buffered(ssl));
-
- int ret = -1;
- piterator iter = pqueue_iterator(ssl->d1->sent_messages);
- pitem *item;
- for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
- hm_fragment *frag = (hm_fragment *)item->data;
- if (dtls1_retransmit_message(ssl, frag) <= 0) {
- goto err;
- }
- }
-
- ret = BIO_flush(ssl->wbio);
- if (ret <= 0) {
- ssl->rwstate = SSL_WRITING;
- goto err;
- }
-
- err:
- if (!was_buffered) {
- ssl_free_wbio_buffer(ssl);
- }
- return ret;
- }
-
- /* dtls1_buffer_change_cipher_spec adds a ChangeCipherSpec to the current
- * handshake flight, ordered just before the handshake message numbered
- * |seq|. */
- static int dtls1_buffer_change_cipher_spec(SSL *ssl, uint16_t seq) {
- hm_fragment *frag = dtls1_hm_fragment_new(0 /* frag_len */,
- 0 /* no reassembly */);
- if (frag == NULL) {
- return 0;
- }
- frag->msg_header.is_ccs = 1;
- frag->msg_header.epoch = ssl->d1->w_epoch;
-
- uint16_t priority = dtls1_get_queue_priority(seq, 1 /* is_ccs */);
- uint8_t seq64be[8];
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(priority >> 8);
- seq64be[7] = (uint8_t)priority;
-
- pitem *item = pitem_new(seq64be, frag);
- if (item == NULL) {
- dtls1_hm_fragment_free(frag);
- return 0;
- }
-
- pqueue_insert(ssl->d1->sent_messages, item);
- return 1;
- }
-
- int dtls1_buffer_message(SSL *ssl) {
- /* this function is called immediately after a message has
- * been serialized */
- assert(ssl->init_off == 0);
-
- hm_fragment *frag = dtls1_hm_fragment_new(ssl->init_num, 0);
- if (!frag) {
- return 0;
- }
-
- memcpy(frag->fragment, ssl->init_buf->data, ssl->init_num);
-
- assert(ssl->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH ==
- (unsigned int)ssl->init_num);
-
- frag->msg_header.msg_len = ssl->d1->w_msg_hdr.msg_len;
- frag->msg_header.seq = ssl->d1->w_msg_hdr.seq;
- frag->msg_header.type = ssl->d1->w_msg_hdr.type;
- frag->msg_header.frag_off = 0;
- frag->msg_header.frag_len = ssl->d1->w_msg_hdr.msg_len;
- frag->msg_header.is_ccs = 0;
- frag->msg_header.epoch = ssl->d1->w_epoch;
-
- uint16_t priority = dtls1_get_queue_priority(frag->msg_header.seq,
- 0 /* handshake */);
- uint8_t seq64be[8];
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(priority >> 8);
- seq64be[7] = (uint8_t)priority;
-
- pitem *item = pitem_new(seq64be, frag);
- if (item == NULL) {
- dtls1_hm_fragment_free(frag);
- return 0;
- }
-
- pqueue_insert(ssl->d1->sent_messages, item);
- return 1;
- }
-
- int dtls1_send_change_cipher_spec(SSL *ssl, int a, int b) {
- if (ssl->state == a) {
- /* Buffer the message to handle retransmits. */
- ssl->d1->handshake_write_seq = ssl->d1->next_handshake_write_seq;
- dtls1_buffer_change_cipher_spec(ssl, ssl->d1->handshake_write_seq);
- ssl->state = b;
- }
-
- return dtls1_write_change_cipher_spec(ssl, dtls1_use_current_epoch);
- }
-
- /* call this function when the buffered messages are no longer needed */
- void dtls1_clear_record_buffer(SSL *ssl) {
- pitem *item;
-
- for (item = pqueue_pop(ssl->d1->sent_messages); item != NULL;
- item = pqueue_pop(ssl->d1->sent_messages)) {
- dtls1_hm_fragment_free((hm_fragment *)item->data);
- pitem_free(item);
- }
- }
-
- /* don't actually do the writing, wait till the MTU has been retrieved */
- void dtls1_set_message_header(SSL *ssl, uint8_t mt, unsigned long len,
- unsigned short seq_num, unsigned long frag_off,
- unsigned long frag_len) {
- struct hm_header_st *msg_hdr = &ssl->d1->w_msg_hdr;
-
- msg_hdr->type = mt;
- msg_hdr->msg_len = len;
- msg_hdr->seq = seq_num;
- msg_hdr->frag_off = frag_off;
- msg_hdr->frag_len = frag_len;
- }
-
- unsigned int dtls1_min_mtu(void) {
- return kMinMTU;
- }
-
- int dtls1_parse_fragment(CBS *cbs, struct hm_header_st *out_hdr,
- CBS *out_body) {
- 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;
- }
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