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e39ac8fb59
boringssl/ssl/d1_both.cc
David Benjamin e39ac8fb59 Switch BORINGSSL_INTERNAL_CXX_TYPES in favor of subclassing games. 
The previous attempt around the 'struct ssl_st' compatibility mess
offended OSS-Fuzz and UBSan because one compilation unit passed a
function pointer with ssl_st* and another called it with
bssl::SSLConnection*.

Linkers don't retain such types, of course, but to silence this alert,
instead make C-visible types be separate from the implementation and
subclass the public type. This does mean we risk polluting the symbol
namespace, but hopefully the compiler is smart enough to inline the
visible struct's constructor and destructor.

Bug: 132
Change-Id: Ia75a89b3a22a202883ad671a630b72d0aeef680e
Reviewed-on: https://boringssl-review.googlesource.com/18224
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>
Reviewed-by: Steven Valdez <svaldez@google.com>
2017-07-20 17:24:12 +00:00

817 lines
28 KiB
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/*
* DTLS implementation written by Nagendra Modadugu
* (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
*/
/* ====================================================================
* Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.] */
#include <openssl/ssl.h>
#include <assert.h>
#include <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 "../crypto/internal.h"
#include "internal.h"
namespace bssl {
/* 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) {
ScopedCBB cbb;
hm_fragment *frag = (hm_fragment *)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 =
(uint8_t *)OPENSSL_malloc(DTLS1_HM_HEADER_LENGTH + msg_hdr->msg_len);
if (frag->data == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!CBB_init_fixed(cbb.get(), frag->data, DTLS1_HM_HEADER_LENGTH) ||
!CBB_add_u8(cbb.get(), msg_hdr->type) ||
!CBB_add_u24(cbb.get(), msg_hdr->msg_len) ||
!CBB_add_u16(cbb.get(), msg_hdr->seq) ||
!CBB_add_u24(cbb.get(), 0 /* frag_off */) ||
!CBB_add_u24(cbb.get(), msg_hdr->msg_len) ||
!CBB_finish(cbb.get(), NULL, NULL)) {
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 = (uint8_t *)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->is_null_cipher()) ||
(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC &&
ssl->s3->aead_read_ctx->is_null_cipher())) {
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) {
static_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]);
enum dtls1_use_epoch_t use_epoch = dtls1_use_current_epoch;
if (ssl->d1->w_epoch >= 1 && msg->epoch == ssl->d1->w_epoch - 1) {
use_epoch = dtls1_use_previous_epoch;
} else if (msg->epoch != ssl->d1->w_epoch) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return seal_error;
}
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. */
ScopedCBB cbb;
uint8_t *frag = out + prefix;
size_t max_frag = max_out - prefix, frag_len;
if (!CBB_init_fixed(cbb.get(), frag, max_frag) ||
!CBB_add_u8(cbb.get(), hdr.type) ||
!CBB_add_u24(cbb.get(), hdr.msg_len) ||
!CBB_add_u16(cbb.get(), hdr.seq) ||
!CBB_add_u24(cbb.get(), ssl->d1->outgoing_offset) ||
!CBB_add_u24(cbb.get(), todo) ||
!CBB_add_bytes(cbb.get(), CBS_data(&body), todo) ||
!CBB_finish(cbb.get(), NULL, &frag_len)) {
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 = (uint8_t *)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;
}
} // namespace bssl
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