/*
* 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 == 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;
}
/* 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, enum dtls1_use_epoch_t use_epoch) {
int ret;
int curr_mtu;
unsigned int len, frag_off;
/* 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. */
size_t max_overhead = SSL_AEAD_CTX_max_overhead(s->aead_write_ctx);
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,
use_epoch);
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 = dtls1_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 < s->max_cert_list) {
return 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 = dtls1_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 = dtls1_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:
pitem_free(item);
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, dtls1_use_current_epoch);
}
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 DTLSv1_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;
/* 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);
/* DTLS renegotiation is unsupported, so only epochs 0 (NULL cipher) and 1
* (negotiated cipher) exist. */
assert(s->d1->w_epoch == 0 || s->d1->w_epoch == 1);
assert(frag->msg_header.epoch <= s->d1->w_epoch);
enum dtls1_use_epoch_t use_epoch = dtls1_use_current_epoch;
if (s->d1->w_epoch == 1 && frag->msg_header.epoch == 0) {
use_epoch = dtls1_use_previous_epoch;
}
ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE,
use_epoch);
(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);
}