pineapple/externals/libressl/ssl/d1_both.c
2022-04-24 22:29:35 +02:00

1198 lines
34 KiB
C
Executable file

/* $OpenBSD: d1_both.c,v 1.81 2022/02/05 14:54:10 jsing Exp $ */
/*
* 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 <limits.h>
#include <stdio.h>
#include <string.h>
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/x509.h>
#include "bytestring.h"
#include "dtls_locl.h"
#include "pqueue.h"
#include "ssl_locl.h"
#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
if ((end) - (start) <= 8) { \
long ii; \
for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
} else { \
long ii; \
bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
} }
#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
long ii; \
OPENSSL_assert((msg_len) > 0); \
is_complete = 1; \
if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
static const unsigned char bitmask_start_values[] = {
0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80
};
static const unsigned char bitmask_end_values[] = {
0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f
};
/* XDTLS: figure out the right values */
static const unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
unsigned long frag_len);
static int dtls1_write_message_header(const struct hm_header_st *msg_hdr,
unsigned long frag_off, unsigned long frag_len, unsigned char *p);
static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max,
int *ok);
void dtls1_hm_fragment_free(hm_fragment *frag);
static hm_fragment *
dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
{
hm_fragment *frag;
if ((frag = calloc(1, sizeof(*frag))) == NULL)
goto err;
if (frag_len > 0) {
if ((frag->fragment = calloc(1, frag_len)) == NULL)
goto err;
}
/* Initialize reassembly bitmask if necessary. */
if (reassembly) {
if ((frag->reassembly = calloc(1,
RSMBLY_BITMASK_SIZE(frag_len))) == NULL)
goto err;
}
return frag;
err:
dtls1_hm_fragment_free(frag);
return NULL;
}
void
dtls1_hm_fragment_free(hm_fragment *frag)
{
if (frag == NULL)
return;
free(frag->fragment);
free(frag->reassembly);
free(frag);
}
/* send s->internal->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 overhead;
/* 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)) {
s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
/*
* I've seen the kernel return bogus numbers when it
* doesn't know the MTU (ie., the initial write), so just
* make sure we have a reasonable number
*/
if (s->d1->mtu < dtls1_min_mtu()) {
s->d1->mtu = 0;
s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
s->d1->mtu, NULL);
}
}
OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());
/* should have something reasonable now */
if (s->internal->init_off == 0 && type == SSL3_RT_HANDSHAKE)
OPENSSL_assert(s->internal->init_num ==
(int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
if (!tls12_record_layer_write_overhead(s->internal->rl, &overhead))
return -1;
frag_off = 0;
while (s->internal->init_num) {
curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
DTLS1_RT_HEADER_LENGTH - overhead;
if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
/* grr.. we could get an error if MTU picked was wrong */
ret = BIO_flush(SSL_get_wbio(s));
if (ret <= 0)
return ret;
curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
overhead;
}
if (s->internal->init_num > curr_mtu)
len = curr_mtu;
else
len = s->internal->init_num;
/* XDTLS: this function is too long. split out the CCS part */
if (type == SSL3_RT_HANDSHAKE) {
if (s->internal->init_off != 0) {
OPENSSL_assert(s->internal->init_off > DTLS1_HM_HEADER_LENGTH);
s->internal->init_off -= DTLS1_HM_HEADER_LENGTH;
s->internal->init_num += DTLS1_HM_HEADER_LENGTH;
if (s->internal->init_num > curr_mtu)
len = curr_mtu;
else
len = s->internal->init_num;
}
dtls1_fix_message_header(s, frag_off,
len - DTLS1_HM_HEADER_LENGTH);
if (!dtls1_write_message_header(&s->d1->w_msg_hdr,
s->d1->w_msg_hdr.frag_off, s->d1->w_msg_hdr.frag_len,
(unsigned char *)&s->internal->init_buf->data[s->internal->init_off]))
return -1;
OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
}
ret = dtls1_write_bytes(s, type,
&s->internal->init_buf->data[s->internal->init_off], len);
if (ret < 0) {
/*
* Might need to update MTU here, but we don't know
* which previous packet caused the failure -- so
* can't really retransmit anything. continue as
* if everything is fine and wait for an alert to
* handle the retransmit
*/
if (BIO_ctrl(SSL_get_wbio(s),
BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0)
s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
else
return (-1);
} else {
/*
* Bad if this assert fails, only part of the
* handshake message got sent. but why would
* this happen?
*/
OPENSSL_assert(len == (unsigned int)ret);
if (type == SSL3_RT_HANDSHAKE &&
!s->d1->retransmitting) {
/*
* Should not be done for 'Hello Request's,
* but in that case we'll ignore the result
* anyway
*/
unsigned char *p = (unsigned char *)&s->internal->init_buf->data[s->internal->init_off];
const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
int xlen;
if (frag_off == 0) {
/*
* Reconstruct message header is if it
* is being sent in single fragment
*/
if (!dtls1_write_message_header(msg_hdr,
0, msg_hdr->msg_len, p))
return (-1);
xlen = ret;
} else {
p += DTLS1_HM_HEADER_LENGTH;
xlen = ret - DTLS1_HM_HEADER_LENGTH;
}
tls1_transcript_record(s, p, xlen);
}
if (ret == s->internal->init_num) {
if (s->internal->msg_callback)
s->internal->msg_callback(1, s->version, type,
s->internal->init_buf->data,
(size_t)(s->internal->init_off + s->internal->init_num),
s, s->internal->msg_callback_arg);
s->internal->init_off = 0;
/* done writing this message */
s->internal->init_num = 0;
return (1);
}
s->internal->init_off += ret;
s->internal->init_num -= ret;
frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
}
}
return (0);
}
/*
* Obtain handshake message of message type 'mt' (any if mt == -1),
* maximum acceptable body length 'max'.
* Read an entire handshake message. Handshake messages arrive in
* fragments.
*/
int
dtls1_get_message(SSL *s, int st1, int stn, int mt, long max)
{
struct hm_header_st *msg_hdr;
unsigned char *p;
unsigned long msg_len;
int i, al, ok;
/*
* s3->internal->tmp is used to store messages that are unexpected, caused
* by the absence of an optional handshake message
*/
if (s->s3->hs.tls12.reuse_message) {
s->s3->hs.tls12.reuse_message = 0;
if ((mt >= 0) && (s->s3->hs.tls12.message_type != mt)) {
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
goto fatal_err;
}
s->internal->init_msg = s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->internal->init_num = (int)s->s3->hs.tls12.message_size;
return 1;
}
msg_hdr = &s->d1->r_msg_hdr;
memset(msg_hdr, 0, sizeof(struct hm_header_st));
again:
i = dtls1_get_message_fragment(s, st1, stn, max, &ok);
if (i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
goto again;
else if (i <= 0 && !ok)
return i;
p = (unsigned char *)s->internal->init_buf->data;
msg_len = msg_hdr->msg_len;
/* reconstruct message header */
if (!dtls1_write_message_header(msg_hdr, 0, msg_len, p))
return -1;
msg_len += DTLS1_HM_HEADER_LENGTH;
tls1_transcript_record(s, p, msg_len);
if (s->internal->msg_callback)
s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, p, msg_len,
s, s->internal->msg_callback_arg);
memset(msg_hdr, 0, sizeof(struct hm_header_st));
/* Don't change sequence numbers while listening */
if (!s->d1->listen)
s->d1->handshake_read_seq++;
s->internal->init_msg = s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return 1;
fatal_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
return -1;
}
static int
dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr, int max)
{
size_t frag_off, frag_len, msg_len;
msg_len = msg_hdr->msg_len;
frag_off = msg_hdr->frag_off;
frag_len = msg_hdr->frag_len;
/* sanity checking */
if ((frag_off + frag_len) > msg_len) {
SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE);
return SSL_AD_ILLEGAL_PARAMETER;
}
if ((frag_off + frag_len) > (unsigned long)max) {
SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE);
return SSL_AD_ILLEGAL_PARAMETER;
}
if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
{
/*
* msg_len is limited to 2^24, but is effectively checked
* against max above
*/
if (!BUF_MEM_grow_clean(s->internal->init_buf,
msg_len + DTLS1_HM_HEADER_LENGTH)) {
SSLerror(s, ERR_R_BUF_LIB);
return SSL_AD_INTERNAL_ERROR;
}
s->s3->hs.tls12.message_size = msg_len;
s->d1->r_msg_hdr.msg_len = msg_len;
s->s3->hs.tls12.message_type = msg_hdr->type;
s->d1->r_msg_hdr.type = msg_hdr->type;
s->d1->r_msg_hdr.seq = msg_hdr->seq;
} else if (msg_len != s->d1->r_msg_hdr.msg_len) {
/*
* They must be playing with us! BTW, failure to enforce
* upper limit would open possibility for buffer overrun.
*/
SSLerror(s, SSL_R_EXCESSIVE_MESSAGE_SIZE);
return SSL_AD_ILLEGAL_PARAMETER;
}
return 0; /* no error */
}
static int
dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
{
/*
* (0) check whether the desired fragment is available
* if so:
* (1) copy over the fragment to s->internal->init_buf->data[]
* (2) update s->internal->init_num
*/
pitem *item;
hm_fragment *frag;
int al;
*ok = 0;
item = pqueue_peek(s->d1->buffered_messages);
if (item == NULL)
return 0;
frag = (hm_fragment *)item->data;
/* Don't return if reassembly still in progress */
if (frag->reassembly != NULL)
return 0;
if (s->d1->handshake_read_seq == frag->msg_header.seq) {
unsigned long frag_len = frag->msg_header.frag_len;
pqueue_pop(s->d1->buffered_messages);
al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
if (al == 0) /* no alert */
{
unsigned char *p = (unsigned char *)s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH;
memcpy(&p[frag->msg_header.frag_off],
frag->fragment, frag->msg_header.frag_len);
}
dtls1_hm_fragment_free(frag);
pitem_free(item);
if (al == 0) {
*ok = 1;
return frag_len;
}
ssl3_send_alert(s, SSL3_AL_FATAL, al);
s->internal->init_num = 0;
*ok = 0;
return -1;
} else
return 0;
}
/*
* 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 unsigned long
dtls1_max_handshake_message_len(const SSL *s)
{
unsigned long max_len;
max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
if (max_len < (unsigned long)s->internal->max_cert_list)
return s->internal->max_cert_list;
return max_len;
}
static int
dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
{
hm_fragment *frag = NULL;
pitem *item = NULL;
int i = -1, is_complete;
unsigned char seq64be[8];
unsigned long frag_len = msg_hdr->frag_len;
if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
goto err;
if (frag_len == 0) {
i = DTLS1_HM_FRAGMENT_RETRY;
goto err;
}
/* Try to find item in queue */
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
seq64be[7] = (unsigned char)msg_hdr->seq;
item = pqueue_find(s->d1->buffered_messages, seq64be);
if (item == NULL) {
frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
if (frag == NULL)
goto err;
memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
frag->msg_header.frag_len = frag->msg_header.msg_len;
frag->msg_header.frag_off = 0;
} else {
frag = (hm_fragment*)item->data;
if (frag->msg_header.msg_len != msg_hdr->msg_len) {
item = NULL;
frag = NULL;
goto err;
}
}
/*
* If message is already reassembled, this must be a
* retransmit and can be dropped.
*/
if (frag->reassembly == NULL) {
unsigned char devnull [256];
while (frag_len) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
devnull, frag_len > sizeof(devnull) ?
sizeof(devnull) : frag_len, 0);
if (i <= 0)
goto err;
frag_len -= i;
}
i = DTLS1_HM_FRAGMENT_RETRY;
goto err;
}
/* read the body of the fragment (header has already been read */
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
frag->fragment + msg_hdr->frag_off, frag_len, 0);
if (i <= 0 || (unsigned long)i != frag_len)
goto err;
RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
(long)(msg_hdr->frag_off + frag_len));
RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
is_complete);
if (is_complete) {
free(frag->reassembly);
frag->reassembly = NULL;
}
if (item == NULL) {
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
seq64be[7] = (unsigned char)(msg_hdr->seq);
item = pitem_new(seq64be, frag);
if (item == NULL) {
i = -1;
goto err;
}
pqueue_insert(s->d1->buffered_messages, item);
}
return DTLS1_HM_FRAGMENT_RETRY;
err:
if (item == NULL && frag != NULL)
dtls1_hm_fragment_free(frag);
*ok = 0;
return i;
}
static int
dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
{
int i = -1;
hm_fragment *frag = NULL;
pitem *item = NULL;
unsigned char seq64be[8];
unsigned long frag_len = msg_hdr->frag_len;
if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
goto err;
/* Try to find item in queue, to prevent duplicate entries */
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char) (msg_hdr->seq >> 8);
seq64be[7] = (unsigned char) msg_hdr->seq;
item = pqueue_find(s->d1->buffered_messages, seq64be);
/*
* If we already have an entry and this one is a fragment,
* don't discard it and rather try to reassemble it.
*/
if (item != NULL && frag_len < msg_hdr->msg_len)
item = NULL;
/*
* Discard the message if sequence number was already there, is
* too far in the future, already in the queue or if we received
* a FINISHED before the SERVER_HELLO, which then must be a stale
* retransmit.
*/
if (msg_hdr->seq <= s->d1->handshake_read_seq ||
msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
(s->d1->handshake_read_seq == 0 &&
msg_hdr->type == SSL3_MT_FINISHED)) {
unsigned char devnull [256];
while (frag_len) {
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
devnull, frag_len > sizeof(devnull) ?
sizeof(devnull) : frag_len, 0);
if (i <= 0)
goto err;
frag_len -= i;
}
} else {
if (frag_len < msg_hdr->msg_len)
return dtls1_reassemble_fragment(s, msg_hdr, ok);
if (frag_len > dtls1_max_handshake_message_len(s))
goto err;
frag = dtls1_hm_fragment_new(frag_len, 0);
if (frag == NULL)
goto err;
memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
if (frag_len) {
/* read the body of the fragment (header has already been read */
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
frag->fragment, frag_len, 0);
if (i <= 0 || (unsigned long)i != frag_len)
goto err;
}
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
seq64be[7] = (unsigned char)(msg_hdr->seq);
item = pitem_new(seq64be, frag);
if (item == NULL)
goto err;
pqueue_insert(s->d1->buffered_messages, item);
}
return DTLS1_HM_FRAGMENT_RETRY;
err:
if (item == NULL && frag != NULL)
dtls1_hm_fragment_free(frag);
*ok = 0;
return i;
}
static long
dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
{
unsigned char wire[DTLS1_HM_HEADER_LENGTH];
unsigned long len, frag_off, frag_len;
struct hm_header_st msg_hdr;
int i, al;
CBS cbs;
again:
/* see if we have the required fragment already */
if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
if (*ok)
s->internal->init_num = frag_len;
return frag_len;
}
/* read handshake message header */
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
DTLS1_HM_HEADER_LENGTH, 0);
if (i <= 0) {
/* nbio, or an error */
s->internal->rwstate = SSL_READING;
*ok = 0;
return i;
}
CBS_init(&cbs, wire, i);
if (!dtls1_get_message_header(&cbs, &msg_hdr)) {
/* Handshake fails if message header is incomplete. */
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
goto fatal_err;
}
/*
* if this is a future (or stale) message it gets buffered
* (or dropped)--no further processing at this time
* While listening, we accept seq 1 (ClientHello with cookie)
* although we're still expecting seq 0 (ClientHello)
*/
if (msg_hdr.seq != s->d1->handshake_read_seq &&
!(s->d1->listen && msg_hdr.seq == 1))
return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
len = msg_hdr.msg_len;
frag_off = msg_hdr.frag_off;
frag_len = msg_hdr.frag_len;
if (frag_len && frag_len < len)
return dtls1_reassemble_fragment(s, &msg_hdr, ok);
if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
wire[0] == SSL3_MT_HELLO_REQUEST) {
/*
* The server may always send 'Hello Request' messages --
* we are doing a handshake anyway now, so ignore them
* if their format is correct. Does not count for
* 'Finished' MAC.
*/
if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
if (s->internal->msg_callback)
s->internal->msg_callback(0, s->version,
SSL3_RT_HANDSHAKE, wire,
DTLS1_HM_HEADER_LENGTH, s,
s->internal->msg_callback_arg);
s->internal->init_num = 0;
goto again;
}
else /* Incorrectly formated Hello request */
{
al = SSL_AD_UNEXPECTED_MESSAGE;
SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
goto fatal_err;
}
}
if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
goto fatal_err;
/* XDTLS: ressurect this when restart is in place */
s->s3->hs.state = stn;
if (frag_len > 0) {
unsigned char *p = (unsigned char *)s->internal->init_buf->data + DTLS1_HM_HEADER_LENGTH;
i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
&p[frag_off], frag_len, 0);
/* XDTLS: fix this--message fragments cannot span multiple packets */
if (i <= 0) {
s->internal->rwstate = SSL_READING;
*ok = 0;
return i;
}
} else
i = 0;
/*
* XDTLS: an incorrectly formatted fragment should cause the
* handshake to fail
*/
if (i != (int)frag_len) {
al = SSL_AD_ILLEGAL_PARAMETER;
SSLerror(s, SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER);
goto fatal_err;
}
/*
* Note that s->internal->init_num is *not* used as current offset in
* s->internal->init_buf->data, but as a counter summing up fragments'
* lengths: as soon as they sum up to handshake packet
* length, we assume we have got all the fragments.
*/
s->internal->init_num = frag_len;
*ok = 1;
return frag_len;
fatal_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
s->internal->init_num = 0;
*ok = 0;
return (-1);
}
int
dtls1_read_failed(SSL *s, int code)
{
if (code > 0) {
#ifdef DEBUG
fprintf(stderr, "invalid state reached %s:%d",
__FILE__, __LINE__);
#endif
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;
}
int
dtls1_retransmit_buffered_messages(SSL *s)
{
pqueue sent = s->d1->sent_messages;
piterator iter;
pitem *item;
hm_fragment *frag;
int found = 0;
iter = pqueue_iterator(sent);
for (item = pqueue_next(&iter); item != NULL;
item = pqueue_next(&iter)) {
frag = (hm_fragment *)item->data;
if (dtls1_retransmit_message(s,
(unsigned short)dtls1_get_queue_priority(
frag->msg_header.seq, frag->msg_header.is_ccs), 0,
&found) <= 0 && found) {
#ifdef DEBUG
fprintf(stderr, "dtls1_retransmit_message() failed\n");
#endif
return -1;
}
}
return 1;
}
int
dtls1_buffer_message(SSL *s, int is_ccs)
{
pitem *item;
hm_fragment *frag;
unsigned char seq64be[8];
/* Buffer the messsage in order to handle DTLS retransmissions. */
/*
* This function is called immediately after a message has
* been serialized
*/
OPENSSL_assert(s->internal->init_off == 0);
frag = dtls1_hm_fragment_new(s->internal->init_num, 0);
if (frag == NULL)
return 0;
memcpy(frag->fragment, s->internal->init_buf->data, s->internal->init_num);
OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
(is_ccs ? DTLS1_CCS_HEADER_LENGTH : DTLS1_HM_HEADER_LENGTH) ==
(unsigned int)s->internal->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;
/* save current state*/
frag->msg_header.saved_retransmit_state.session = s->session;
frag->msg_header.saved_retransmit_state.epoch =
tls12_record_layer_write_epoch(s->internal->rl);
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char)(dtls1_get_queue_priority(
frag->msg_header.seq, frag->msg_header.is_ccs) >> 8);
seq64be[7] = (unsigned char)(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;
}
int
dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
int *found)
{
int ret;
/* XDTLS: for now assuming that read/writes are blocking */
pitem *item;
hm_fragment *frag;
unsigned long header_length;
unsigned char seq64be[8];
struct dtls1_retransmit_state saved_state;
/*
OPENSSL_assert(s->internal->init_num == 0);
OPENSSL_assert(s->internal->init_off == 0);
*/
/* XDTLS: the requested message ought to be found, otherwise error */
memset(seq64be, 0, sizeof(seq64be));
seq64be[6] = (unsigned char)(seq >> 8);
seq64be[7] = (unsigned char)seq;
item = pqueue_find(s->d1->sent_messages, seq64be);
if (item == NULL) {
#ifdef DEBUG
fprintf(stderr, "retransmit: message %d non-existent\n", seq);
#endif
*found = 0;
return 0;
}
*found = 1;
frag = (hm_fragment *)item->data;
if (frag->msg_header.is_ccs)
header_length = DTLS1_CCS_HEADER_LENGTH;
else
header_length = DTLS1_HM_HEADER_LENGTH;
memcpy(s->internal->init_buf->data, frag->fragment,
frag->msg_header.msg_len + header_length);
s->internal->init_num = frag->msg_header.msg_len + header_length;
dtls1_set_message_header_int(s, frag->msg_header.type,
frag->msg_header.msg_len, frag->msg_header.seq, 0,
frag->msg_header.frag_len);
/* save current state */
saved_state.session = s->session;
saved_state.epoch = tls12_record_layer_write_epoch(s->internal->rl);
s->d1->retransmitting = 1;
/* restore state in which the message was originally sent */
s->session = frag->msg_header.saved_retransmit_state.session;
if (!tls12_record_layer_use_write_epoch(s->internal->rl,
frag->msg_header.saved_retransmit_state.epoch))
return 0;
ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
/* restore current state */
s->session = saved_state.session;
if (!tls12_record_layer_use_write_epoch(s->internal->rl,
saved_state.epoch))
return 0;
s->d1->retransmitting = 0;
(void)BIO_flush(SSL_get_wbio(s));
return ret;
}
/* call this function when the buffered messages are no longer needed */
void
dtls1_clear_record_buffer(SSL *s)
{
hm_fragment *frag;
pitem *item;
for(item = pqueue_pop(s->d1->sent_messages); item != NULL;
item = pqueue_pop(s->d1->sent_messages)) {
frag = item->data;
if (frag->msg_header.is_ccs)
tls12_record_layer_write_epoch_done(s->internal->rl,
frag->msg_header.saved_retransmit_state.epoch);
dtls1_hm_fragment_free(frag);
pitem_free(item);
}
}
void
dtls1_set_message_header(SSL *s, unsigned char mt, unsigned long len,
unsigned long frag_off, unsigned long frag_len)
{
/* Don't change sequence numbers while listening */
if (frag_off == 0 && !s->d1->listen) {
s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
s->d1->next_handshake_write_seq++;
}
dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
frag_off, frag_len);
}
/* don't actually do the writing, wait till the MTU has been retrieved */
void
dtls1_set_message_header_int(SSL *s, unsigned char 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 int
dtls1_write_message_header(const struct hm_header_st *msg_hdr,
unsigned long frag_off, unsigned long frag_len, unsigned char *p)
{
CBB cbb;
/* We assume DTLS1_HM_HEADER_LENGTH bytes are available for now... */
if (!CBB_init_fixed(&cbb, p, DTLS1_HM_HEADER_LENGTH))
return 0;
if (!CBB_add_u8(&cbb, msg_hdr->type))
goto err;
if (!CBB_add_u24(&cbb, msg_hdr->msg_len))
goto err;
if (!CBB_add_u16(&cbb, msg_hdr->seq))
goto err;
if (!CBB_add_u24(&cbb, frag_off))
goto err;
if (!CBB_add_u24(&cbb, frag_len))
goto err;
if (!CBB_finish(&cbb, NULL, NULL))
goto err;
return 1;
err:
CBB_cleanup(&cbb);
return 0;
}
unsigned int
dtls1_min_mtu(void)
{
return (g_probable_mtu[(sizeof(g_probable_mtu) /
sizeof(g_probable_mtu[0])) - 1]);
}
static unsigned int
dtls1_guess_mtu(unsigned int curr_mtu)
{
unsigned int i;
if (curr_mtu == 0)
return g_probable_mtu[0];
for (i = 0; i < sizeof(g_probable_mtu) / sizeof(g_probable_mtu[0]); i++)
if (curr_mtu > g_probable_mtu[i])
return g_probable_mtu[i];
return curr_mtu;
}
int
dtls1_get_message_header(CBS *header, struct hm_header_st *msg_hdr)
{
uint32_t msg_len, frag_off, frag_len;
uint16_t seq;
uint8_t type;
memset(msg_hdr, 0, sizeof(*msg_hdr));
if (!CBS_get_u8(header, &type))
return 0;
if (!CBS_get_u24(header, &msg_len))
return 0;
if (!CBS_get_u16(header, &seq))
return 0;
if (!CBS_get_u24(header, &frag_off))
return 0;
if (!CBS_get_u24(header, &frag_len))
return 0;
msg_hdr->type = type;
msg_hdr->msg_len = msg_len;
msg_hdr->seq = seq;
msg_hdr->frag_off = frag_off;
msg_hdr->frag_len = frag_len;
return 1;
}