- /*
- * 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 <assert.h>
- #include <limits.h>
- #include <stdio.h>
- #include <string.h>
-
- #include <openssl/buf.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/mem.h>
- #include <openssl/obj.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 void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
- unsigned long frag_len);
- static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
-
- static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
- int reassembly) {
- hm_fragment *frag = NULL;
- uint8_t *buf = NULL;
- uint8_t *bitmask = NULL;
-
- frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
- if (frag == NULL) {
- OPENSSL_PUT_ERROR(SSL, dtls1_hm_fragment_new, ERR_R_MALLOC_FAILURE);
- return NULL;
- }
-
- if (frag_len) {
- buf = (uint8_t *)OPENSSL_malloc(frag_len);
- if (buf == NULL) {
- OPENSSL_PUT_ERROR(SSL, dtls1_hm_fragment_new, ERR_R_MALLOC_FAILURE);
- OPENSSL_free(frag);
- return NULL;
- }
- }
-
- /* zero length fragment gets zero frag->fragment */
- frag->fragment = buf;
-
- /* Initialize reassembly bitmask if necessary */
- if (reassembly && frag_len > 0) {
- if (frag_len + 7 < frag_len) {
- OPENSSL_PUT_ERROR(SSL, dtls1_hm_fragment_new, ERR_R_OVERFLOW);
- return NULL;
- }
- size_t bitmask_len = (frag_len + 7) / 8;
- bitmask = (uint8_t *)OPENSSL_malloc(bitmask_len);
- if (bitmask == NULL) {
- OPENSSL_PUT_ERROR(SSL, dtls1_hm_fragment_new, ERR_R_MALLOC_FAILURE);
- if (buf != NULL) {
- OPENSSL_free(buf);
- }
- OPENSSL_free(frag);
- return NULL;
- }
- memset(bitmask, 0, bitmask_len);
- }
-
- frag->reassembly = bitmask;
-
- return frag;
- }
-
- void dtls1_hm_fragment_free(hm_fragment *frag) {
- if (frag->fragment) {
- OPENSSL_free(frag->fragment);
- }
- if (frag->reassembly) {
- 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;
- }
-
- /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
- * SSL3_RT_CHANGE_CIPHER_SPEC) */
- int dtls1_do_write(SSL *s, int type) {
- int ret;
- int curr_mtu;
- unsigned int len, frag_off;
- size_t max_overhead = 0;
-
- /* AHA! Figure out the MTU, and stick to the right size */
- if (s->d1->mtu < dtls1_min_mtu() &&
- !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
- long mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
- if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) {
- s->d1->mtu = (unsigned)mtu;
- } else {
- s->d1->mtu = kDefaultMTU;
- BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, s->d1->mtu, NULL);
- }
- }
-
- /* should have something reasonable now */
- assert(s->d1->mtu >= dtls1_min_mtu());
-
- if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
- assert(s->init_num ==
- (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
- }
-
- /* Determine the maximum overhead of the current cipher. */
- if (s->aead_write_ctx != NULL) {
- max_overhead = EVP_AEAD_max_overhead(s->aead_write_ctx->ctx.aead);
- if (s->aead_write_ctx->variable_nonce_included_in_record) {
- max_overhead += s->aead_write_ctx->variable_nonce_len;
- }
- }
-
- frag_off = 0;
- while (s->init_num) {
- /* Account for data in the buffering BIO; multiple records may be packed
- * into a single packet during the handshake.
- *
- * TODO(davidben): This is buggy; if the MTU is larger than the buffer size,
- * the large record will be split across two packets. Moreover, in that
- * case, the |dtls1_write_bytes| call may not return synchronously. This
- * will break on retry as the |s->init_off| and |s->init_num| adjustment
- * will run a second time. */
- curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
- DTLS1_RT_HEADER_LENGTH - max_overhead;
-
- if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
- /* Flush the buffer and continue with a fresh packet.
- *
- * TODO(davidben): If |BIO_flush| is not synchronous and requires multiple
- * calls to |dtls1_do_write|, |frag_off| will be wrong. */
- ret = BIO_flush(SSL_get_wbio(s));
- if (ret <= 0) {
- return ret;
- }
- assert(BIO_wpending(SSL_get_wbio(s)) == 0);
- curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH - max_overhead;
- }
-
- /* XDTLS: this function is too long. split out the CCS part */
- if (type == SSL3_RT_HANDSHAKE) {
- /* If this isn't the first fragment, reserve space to prepend a new
- * fragment header. This will override the body of a previous fragment. */
- if (s->init_off != 0) {
- assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
- s->init_off -= DTLS1_HM_HEADER_LENGTH;
- s->init_num += DTLS1_HM_HEADER_LENGTH;
- }
-
- if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
- /* To make forward progress, the MTU must, at minimum, fit the handshake
- * header and one byte of handshake body. */
- OPENSSL_PUT_ERROR(SSL, dtls1_do_write, SSL_R_MTU_TOO_SMALL);
- return -1;
- }
-
- if (s->init_num > curr_mtu) {
- len = curr_mtu;
- } else {
- len = s->init_num;
- }
- assert(len >= DTLS1_HM_HEADER_LENGTH);
-
- dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
- dtls1_write_message_header(
- s, (uint8_t *)&s->init_buf->data[s->init_off]);
- } else {
- assert(type == SSL3_RT_CHANGE_CIPHER_SPEC);
- /* ChangeCipherSpec cannot be fragmented. */
- if (s->init_num > curr_mtu) {
- OPENSSL_PUT_ERROR(SSL, dtls1_do_write, SSL_R_MTU_TOO_SMALL);
- return -1;
- }
- len = s->init_num;
- }
-
- ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len);
- if (ret < 0) {
- return -1;
- }
-
- /* bad if this assert fails, only part of the handshake message got sent.
- * But why would this happen? */
- assert(len == (unsigned int)ret);
-
- if (ret == s->init_num) {
- if (s->msg_callback) {
- s->msg_callback(1, s->version, type, s->init_buf->data,
- (size_t)(s->init_off + s->init_num), s,
- s->msg_callback_arg);
- }
-
- s->init_off = 0; /* done writing this message */
- s->init_num = 0;
-
- return 1;
- }
- s->init_off += ret;
- s->init_num -= ret;
- frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
- }
-
- return 0;
- }
-
- /* 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 *s) {
- pitem *item = pqueue_peek(s->d1->buffered_messages);
- if (item == NULL) {
- return 0;
- }
-
- hm_fragment *frag = (hm_fragment *)item->data;
- assert(s->d1->handshake_read_seq <= frag->msg_header.seq);
-
- return s->d1->handshake_read_seq == frag->msg_header.seq &&
- frag->reassembly == NULL;
- }
-
- /* dtls1_discard_fragment_body discards a handshake fragment body of length
- * |frag_len|. It returns one on success and zero on error.
- *
- * TODO(davidben): This function will go away when ssl_read_bytes is gone from
- * the DTLS side. */
- static int dtls1_discard_fragment_body(SSL *s, size_t frag_len) {
- uint8_t discard[256];
- while (frag_len > 0) {
- size_t chunk = frag_len < sizeof(discard) ? frag_len : sizeof(discard);
- int ret = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, discard, chunk,
- 0);
- if (ret != chunk) {
- return 0;
- }
- frag_len -= chunk;
- }
- return 1;
- }
-
- /* 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 *s, 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(s->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(s->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, dtls1_get_buffered_message,
- SSL_R_FRAGMENT_MISMATCH);
- ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return NULL;
- }
- }
- return frag;
- }
-
- /* dtls1_max_handshake_message_len returns the maximum number of bytes
- * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
- * be greater if the maximum certificate list size requires it. */
- static size_t dtls1_max_handshake_message_len(const SSL *s) {
- size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
- if (max_len < (size_t)s->max_cert_list) {
- return (size_t)s->max_cert_list;
- }
- return max_len;
- }
-
- /* dtls1_process_fragment reads a handshake fragment and processes it. It
- * returns one if a fragment was successfully processed and 0 or -1 on error. */
- static int dtls1_process_fragment(SSL *s) {
- /* Read handshake message header.
- *
- * TODO(davidben): ssl_read_bytes allows splitting the fragment header and
- * body across two records. Change this interface to consume the fragment in
- * one pass. */
- uint8_t header[DTLS1_HM_HEADER_LENGTH];
- int ret = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, header,
- DTLS1_HM_HEADER_LENGTH, 0);
- if (ret <= 0) {
- return ret;
- }
- if (ret != DTLS1_HM_HEADER_LENGTH) {
- OPENSSL_PUT_ERROR(SSL, dtls1_process_fragment, SSL_R_UNEXPECTED_MESSAGE);
- ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- return -1;
- }
-
- /* Parse the message fragment header. */
- struct hm_header_st msg_hdr;
- dtls1_get_message_header(header, &msg_hdr);
-
- 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 > dtls1_max_handshake_message_len(s)) {
- OPENSSL_PUT_ERROR(SSL, dtls1_process_fragment,
- SSL_R_EXCESSIVE_MESSAGE_SIZE);
- ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
- return -1;
- }
-
- if (msg_hdr.seq < s->d1->handshake_read_seq ||
- msg_hdr.seq > (unsigned)s->d1->handshake_read_seq +
- kHandshakeBufferSize) {
- /* Ignore fragments from the past, or ones too far in the future. */
- if (!dtls1_discard_fragment_body(s, frag_len)) {
- return -1;
- }
- return 1;
- }
-
- hm_fragment *frag = dtls1_get_buffered_message(s, &msg_hdr);
- if (frag == NULL) {
- return -1;
- }
- assert(frag->msg_header.msg_len == msg_len);
-
- if (frag->reassembly == NULL) {
- /* The message is already assembled. */
- if (!dtls1_discard_fragment_body(s, frag_len)) {
- return -1;
- }
- return 1;
- }
- assert(msg_len > 0);
-
- /* Read the body of the fragment. */
- ret = s->method->ssl_read_bytes(
- s, SSL3_RT_HANDSHAKE, frag->fragment + frag_off, frag_len, 0);
- if (ret != frag_len) {
- OPENSSL_PUT_ERROR(SSL, dtls1_process_fragment, SSL_R_UNEXPECTED_MESSAGE);
- ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
- return -1;
- }
- dtls1_hm_fragment_mark(frag, frag_off, frag_off + frag_len);
-
- return 1;
- }
-
- /* dtls1_get_message reads a handshake message of message type |msg_type| (any
- * if |msg_type| == -1), maximum acceptable body length |max|. Read an entire
- * handshake message. Handshake messages arrive in fragments. */
- long dtls1_get_message(SSL *s, int st1, int stn, int msg_type, long max,
- 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 (s->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);
- s->s3->tmp.reuse_message = 0;
- if (msg_type >= 0 && s->s3->tmp.message_type != msg_type) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- *ok = 1;
- s->init_msg = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- s->init_num = (int)s->s3->tmp.message_size;
- return s->init_num;
- }
-
- /* Process fragments until one is found. */
- while (!dtls1_is_next_message_complete(s)) {
- int ret = dtls1_process_fragment(s);
- if (ret <= 0) {
- *ok = 0;
- return ret;
- }
- }
-
- /* Read out the next complete handshake message. */
- item = pqueue_pop(s->d1->buffered_messages);
- assert(item != NULL);
- frag = (hm_fragment *)item->data;
- assert(s->d1->handshake_read_seq == frag->msg_header.seq);
- assert(frag->reassembly == NULL);
-
- if (frag->msg_header.msg_len > (size_t)max) {
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, SSL_R_EXCESSIVE_MESSAGE_SIZE);
- goto err;
- }
-
- CBB cbb;
- if (!BUF_MEM_grow(s->init_buf,
- (size_t)frag->msg_header.msg_len +
- DTLS1_HM_HEADER_LENGTH) ||
- !CBB_init_fixed(&cbb, (uint8_t *)s->init_buf->data, s->init_buf->max)) {
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- /* Reconstruct the assembled message. */
- size_t len;
- if (!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, &len)) {
- CBB_cleanup(&cbb);
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, ERR_R_INTERNAL_ERROR);
- goto err;
- }
- assert(len == (size_t)frag->msg_header.msg_len + DTLS1_HM_HEADER_LENGTH);
-
- s->d1->handshake_read_seq++;
-
- /* TODO(davidben): This function has a lot of implicit outputs. Simplify the
- * |ssl_get_message| API. */
- s->s3->tmp.message_type = frag->msg_header.type;
- s->s3->tmp.message_size = frag->msg_header.msg_len;
- s->init_msg = (uint8_t *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
- s->init_num = frag->msg_header.msg_len;
-
- if (msg_type >= 0 && s->s3->tmp.message_type != msg_type) {
- al = SSL_AD_UNEXPECTED_MESSAGE;
- OPENSSL_PUT_ERROR(SSL, dtls1_get_message, SSL_R_UNEXPECTED_MESSAGE);
- goto f_err;
- }
- if (hash_message == ssl_hash_message && !ssl3_hash_current_message(s)) {
- goto err;
- }
- if (s->msg_callback) {
- s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
- s->init_num + DTLS1_HM_HEADER_LENGTH, s,
- s->msg_callback_arg);
- }
-
- pitem_free(item);
- dtls1_hm_fragment_free(frag);
-
- s->state = stn;
- *ok = 1;
- return s->init_num;
-
- f_err:
- ssl3_send_alert(s, SSL3_AL_FATAL, al);
- err:
- if (item != NULL) {
- pitem_free(item);
- }
- if (frag != NULL) {
- dtls1_hm_fragment_free(frag);
- }
- *ok = 0;
- return -1;
- }
-
- /* for these 2 messages, we need to
- * ssl->enc_read_ctx re-init
- * ssl->s3->read_sequence zero
- * ssl->s3->read_mac_secret re-init
- * ssl->session->read_sym_enc assign
- * ssl->session->read_compression assign
- * ssl->session->read_hash assign */
- int dtls1_send_change_cipher_spec(SSL *s, int a, int b) {
- uint8_t *p;
-
- if (s->state == a) {
- p = (uint8_t *)s->init_buf->data;
- *p++ = SSL3_MT_CCS;
- s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
- s->init_num = DTLS1_CCS_HEADER_LENGTH;
-
- s->init_off = 0;
-
- dtls1_set_message_header(s, SSL3_MT_CCS, 0, s->d1->handshake_write_seq, 0,
- 0);
-
- /* buffer the message to handle re-xmits */
- dtls1_buffer_message(s, 1);
-
- s->state = b;
- }
-
- /* SSL3_ST_CW_CHANGE_B */
- return dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC);
- }
-
- int dtls1_read_failed(SSL *s, int code) {
- if (code > 0) {
- assert(0);
- return 1;
- }
-
- if (!dtls1_is_timer_expired(s)) {
- /* not a timeout, none of our business, let higher layers handle this. In
- * fact, it's probably an error */
- return code;
- }
-
- if (!SSL_in_init(s)) {
- /* done, no need to send a retransmit */
- BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
- return code;
- }
-
- return dtls1_handle_timeout(s);
- }
-
- int dtls1_get_queue_priority(unsigned short seq, int is_ccs) {
- /* 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 *s, hm_fragment *frag) {
- int ret;
- /* XDTLS: for now assuming that read/writes are blocking */
- unsigned long header_length;
- uint8_t save_write_sequence[8];
-
- /* assert(s->init_num == 0);
- assert(s->init_off == 0); */
-
- if (frag->msg_header.is_ccs) {
- header_length = DTLS1_CCS_HEADER_LENGTH;
- } else {
- header_length = DTLS1_HM_HEADER_LENGTH;
- }
-
- memcpy(s->init_buf->data, frag->fragment,
- frag->msg_header.msg_len + header_length);
- s->init_num = frag->msg_header.msg_len + header_length;
-
- dtls1_set_message_header(s, frag->msg_header.type,
- frag->msg_header.msg_len, frag->msg_header.seq,
- 0, frag->msg_header.frag_len);
-
- /* Save current state. */
- SSL_AEAD_CTX *aead_write_ctx = s->aead_write_ctx;
- uint16_t epoch = s->d1->w_epoch;
-
- /* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1
- * (negotiated cipher) exist. */
- assert(epoch == 0 || epoch == 1);
- assert(frag->msg_header.epoch <= epoch);
- const int fragment_from_previous_epoch = (epoch == 1 &&
- frag->msg_header.epoch == 0);
- if (fragment_from_previous_epoch) {
- /* Rewind to the previous epoch.
- *
- * TODO(davidben): Instead of swapping out connection-global state, this
- * logic should pass a "use previous epoch" parameter down to lower-level
- * functions. */
- s->d1->w_epoch = frag->msg_header.epoch;
- s->aead_write_ctx = NULL;
- memcpy(save_write_sequence, s->s3->write_sequence,
- sizeof(s->s3->write_sequence));
- memcpy(s->s3->write_sequence, s->d1->last_write_sequence,
- sizeof(s->s3->write_sequence));
- } else {
- /* Otherwise the messages must be from the same epoch. */
- assert(frag->msg_header.epoch == epoch);
- }
-
- ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC
- : SSL3_RT_HANDSHAKE);
-
- if (fragment_from_previous_epoch) {
- /* Restore the current epoch. */
- s->aead_write_ctx = aead_write_ctx;
- s->d1->w_epoch = epoch;
- memcpy(s->d1->last_write_sequence, s->s3->write_sequence,
- sizeof(s->s3->write_sequence));
- memcpy(s->s3->write_sequence, save_write_sequence,
- sizeof(s->s3->write_sequence));
- }
-
- (void)BIO_flush(SSL_get_wbio(s));
- return ret;
- }
-
-
- int dtls1_retransmit_buffered_messages(SSL *s) {
- pqueue sent = s->d1->sent_messages;
- piterator iter = pqueue_iterator(sent);
- pitem *item;
-
- for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
- hm_fragment *frag = (hm_fragment *)item->data;
- if (dtls1_retransmit_message(s, frag) <= 0) {
- return -1;
- }
- }
-
- return 1;
- }
-
- int dtls1_buffer_message(SSL *s, int is_ccs) {
- pitem *item;
- hm_fragment *frag;
- uint8_t seq64be[8];
-
- /* this function is called immediately after a message has
- * been serialized */
- assert(s->init_off == 0);
-
- frag = dtls1_hm_fragment_new(s->init_num, 0);
- if (!frag) {
- return 0;
- }
-
- memcpy(frag->fragment, s->init_buf->data, s->init_num);
-
- if (is_ccs) {
- assert(s->d1->w_msg_hdr.msg_len + DTLS1_CCS_HEADER_LENGTH ==
- (unsigned int)s->init_num);
- } else {
- assert(s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH ==
- (unsigned int)s->init_num);
- }
-
- frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
- frag->msg_header.seq = s->d1->w_msg_hdr.seq;
- frag->msg_header.type = s->d1->w_msg_hdr.type;
- frag->msg_header.frag_off = 0;
- frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
- frag->msg_header.is_ccs = is_ccs;
- frag->msg_header.epoch = s->d1->w_epoch;
-
- memset(seq64be, 0, sizeof(seq64be));
- seq64be[6] = (uint8_t)(
- dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs) >>
- 8);
- seq64be[7] = (uint8_t)(
- dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs));
-
- item = pitem_new(seq64be, frag);
- if (item == NULL) {
- dtls1_hm_fragment_free(frag);
- return 0;
- }
-
- pqueue_insert(s->d1->sent_messages, item);
- return 1;
- }
-
- /* call this function when the buffered messages are no longer needed */
- void dtls1_clear_record_buffer(SSL *s) {
- pitem *item;
-
- for (item = pqueue_pop(s->d1->sent_messages); item != NULL;
- item = pqueue_pop(s->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 *s, uint8_t mt, unsigned long len,
- unsigned short seq_num, unsigned long frag_off,
- unsigned long frag_len) {
- struct hm_header_st *msg_hdr = &s->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;
- }
-
- static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
- unsigned long frag_len) {
- struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-
- msg_hdr->frag_off = frag_off;
- msg_hdr->frag_len = frag_len;
- }
-
- static uint8_t *dtls1_write_message_header(SSL *s, uint8_t *p) {
- struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-
- *p++ = msg_hdr->type;
- l2n3(msg_hdr->msg_len, p);
-
- s2n(msg_hdr->seq, p);
- l2n3(msg_hdr->frag_off, p);
- l2n3(msg_hdr->frag_len, p);
-
- return p;
- }
-
- unsigned int dtls1_min_mtu(void) {
- return kMinMTU;
- }
-
- void dtls1_get_message_header(uint8_t *data,
- struct hm_header_st *msg_hdr) {
- memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
- msg_hdr->type = *(data++);
- n2l3(data, msg_hdr->msg_len);
-
- n2s(data, msg_hdr->seq);
- n2l3(data, msg_hdr->frag_off);
- n2l3(data, msg_hdr->frag_len);
- }
-
- int dtls1_shutdown(SSL *s) {
- int ret;
- ret = ssl3_shutdown(s);
- return ret;
- }
|