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d1_both.c
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/* ssl/d1_both.c */
/*
* DTLS implementation written by Nagendra Modadugu
* ([email protected]) 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
*
* 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
* ([email protected]). This product includes software written by Tim
* Hudson ([email protected]).
*
*/
/* Copyright (C) 1995-1998 Eric Young ([email protected])
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young ([email protected]).
* 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 ([email protected]).
*
* 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 ([email protected])"
* 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 ([email protected])"
*
* 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 <string.h>
#include <stdio.h>
#include "ssl_locl.h"
#include <openssl/buffer.h>
#include <openssl/rand.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/x509.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; } }
#if 0
#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
long ii; \
printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
printf("\n"); }
#endif
static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
/* XDTLS: figure out the right values */
static 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 unsigned char *dtls1_write_message_header(SSL *s,
unsigned char *p);
static 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);
static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
long max, int *ok);
static hm_fragment *
dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
{
hm_fragment *frag = NULL;
unsigned char *buf = NULL;
unsigned char *bitmask = NULL;
frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
if ( frag == NULL)
return NULL;
if (frag_len)
{
buf = (unsigned char *)OPENSSL_malloc(frag_len);
if ( buf == NULL)
{
OPENSSL_free(frag);
return NULL;
}
}
/* zero length fragment gets zero frag->fragment */
frag->fragment = buf;
/* Initialize reassembly bitmask if necessary */
if (reassembly)
{
bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
if (bitmask == NULL)
{
if (buf != NULL) OPENSSL_free(buf);
OPENSSL_free(frag);
return NULL;
}
memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
}
frag->reassembly = bitmask;
return frag;
}
static void
dtls1_hm_fragment_free(hm_fragment *frag)
{
if (frag->msg_header.is_ccs)
{
EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
}
if (frag->fragment) OPENSSL_free(frag->fragment);
if (frag->reassembly) OPENSSL_free(frag->reassembly);
OPENSSL_free(frag);
}
/* 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, mac_size, blocksize;
/* 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
* (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);
}
}
#if 0
mtu = s->d1->mtu;
fprintf(stderr, "using MTU = %d\n", mtu);
mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
if ( curr_mtu > 0)
mtu = curr_mtu;
else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
return ret;
if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
{
ret = BIO_flush(SSL_get_wbio(s));
if ( ret <= 0)
return ret;
mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
}
#endif
OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
OPENSSL_assert(s->init_num ==
(int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
if (s->write_hash)
mac_size = EVP_MD_CTX_size(s->write_hash);
else
mac_size = 0;
if (s->enc_write_ctx &&
(EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
else
blocksize = 0;
frag_off = 0;
while( s->init_num)
{
curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
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 -
mac_size - blocksize;
}
if ( s->init_num > curr_mtu)
len = curr_mtu;
else
len = s->init_num;
/* XDTLS: this function is too long. split out the CCS part */
if ( type == SSL3_RT_HANDSHAKE)
{
if ( s->init_off != 0)
{
OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
s->init_off -= DTLS1_HM_HEADER_LENGTH;
s->init_num += DTLS1_HM_HEADER_LENGTH;
if ( s->init_num > curr_mtu)
len = curr_mtu;
else
len = s->init_num;
}
dtls1_fix_message_header(s, frag_off,
len - DTLS1_HM_HEADER_LENGTH);
dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
}
ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->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->init_buf->data[s->init_off];
const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
int xlen;
if (frag_off == 0 && s->version != DTLS1_BAD_VER)
{
/* reconstruct message header is if it
* is being sent in single fragment */
*p++ = msg_hdr->type;
l2n3(msg_hdr->msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_hdr->msg_len,p);
p -= DTLS1_HM_HEADER_LENGTH;
xlen = ret;
}
else
{
p += DTLS1_HM_HEADER_LENGTH;
xlen = ret - DTLS1_HM_HEADER_LENGTH;
}
ssl3_finish_mac(s, p, xlen);
}
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);
}
/* 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.
*/
long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
{
int i, al;
struct hm_header_st *msg_hdr;
unsigned char *p;
unsigned long msg_len;
/* 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)
{
s->s3->tmp.reuse_message=0;
if ((mt >= 0) && (s->s3->tmp.message_type != mt))
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
*ok=1;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
s->init_num = (int)s->s3->tmp.message_size;
return s->init_num;
}
msg_hdr = &s->d1->r_msg_hdr;
memset(msg_hdr, 0x00, 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->init_buf->data;
msg_len = msg_hdr->msg_len;
/* reconstruct message header */
*(p++) = msg_hdr->type;
l2n3(msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_len,p);
if (s->version != DTLS1_BAD_VER) {
p -= DTLS1_HM_HEADER_LENGTH;
msg_len += DTLS1_HM_HEADER_LENGTH;
}
ssl3_finish_mac(s, p, msg_len);
if (s->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
p, msg_len,
s, s->msg_callback_arg);
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
/* Don't change sequence numbers while listening */
if (!s->d1->listen)
s->d1->handshake_read_seq++;
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
*ok = 0;
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)
{
SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
return SSL_AD_ILLEGAL_PARAMETER;
}
if ( (frag_off+frag_len) > (unsigned long)max)
{
SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,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->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
{
SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
return SSL_AD_INTERNAL_ERROR;
}
s->s3->tmp.message_size = msg_len;
s->d1->r_msg_hdr.msg_len = msg_len;
s->s3->tmp.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. */
SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,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->init_buf->data[]
* (2) update s->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->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->init_num = 0;
*ok = 0;
return -1;
}
else
return 0;
}
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, max_len;
if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
goto err;
/* Determine maximum allowed message size. Depends on (user set)
* maximum certificate length, but 16k is minimum.
*/
if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
max_len = s->max_cert_list;
else
max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
if ((msg_hdr->frag_off+frag_len) > max_len)
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 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;
}
return DTLS1_HM_FRAGMENT_RETRY;
}
/* 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)
{
OPENSSL_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)
{
goto err;
i = -1;
}
pqueue_insert(s->d1->buffered_messages, item);
}
return DTLS1_HM_FRAGMENT_RETRY;
err:
if (frag != NULL) dtls1_hm_fragment_free(frag);
if (item != NULL) OPENSSL_free(item);
*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 && frag_len < msg_hdr->msg_len)
return dtls1_reassemble_fragment(s, msg_hdr, ok);
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 ( frag != NULL) dtls1_hm_fragment_free(frag);
if ( item != NULL) OPENSSL_free(item);
*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;
int i,al;
struct hm_header_st msg_hdr;
/* see if we have the required fragment already */
if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
{
if (*ok) s->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->rwstate=SSL_READING;
*ok = 0;
return i;
}
/* Handshake fails if message header is incomplete */
if (i != DTLS1_HM_HEADER_LENGTH)
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
/* parse the message fragment header */
dtls1_get_message_header(wire, &msg_hdr);
/*
* 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->msg_callback)
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
wire, DTLS1_HM_HEADER_LENGTH, s,
s->msg_callback_arg);
s->init_num = 0;
return dtls1_get_message_fragment(s, st1, stn,
max, ok);
}
else /* Incorrectly formated Hello request */
{
al=SSL_AD_UNEXPECTED_MESSAGE;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
}
if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
goto f_err;
/* XDTLS: ressurect this when restart is in place */
s->state=stn;
if ( frag_len > 0)
{
unsigned char *p=(unsigned char *)s->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->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=SSL3_AD_ILLEGAL_PARAMETER;
SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
goto f_err;
}
*ok = 1;
/* Note that s->init_num is *not* used as current offset in
* s->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->init_num = frag_len;
return frag_len;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
s->init_num = 0;
*ok=0;
return(-1);
}
int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
{
unsigned char *p,*d;
int i;
unsigned long l;
if (s->state == a)
{
d=(unsigned char *)s->init_buf->data;
p= &(d[DTLS1_HM_HEADER_LENGTH]);
i=s->method->ssl3_enc->final_finish_mac(s,
sender,slen,s->s3->tmp.finish_md);
s->s3->tmp.finish_md_len = i;
memcpy(p, s->s3->tmp.finish_md, i);
p+=i;
l=i;
/* Copy the finished so we can use it for
* renegotiation checks
*/
if(s->type == SSL_ST_CONNECT)
{
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_client_finished,
s->s3->tmp.finish_md, i);
s->s3->previous_client_finished_len=i;
}
else
{
OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
memcpy(s->s3->previous_server_finished,
s->s3->tmp.finish_md, i);
s->s3->previous_server_finished_len=i;
}
#ifdef OPENSSL_SYS_WIN16
/* MSVC 1.5 does not clear the top bytes of the word unless
* I do this.
*/
l&=0xffff;
#endif
d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
s->init_off=0;
/* buffer the message to handle re-xmits */
dtls1_buffer_message(s, 0);
s->state=b;
}
/* SSL3_ST_SEND_xxxxxx_HELLO_B */
return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
}
/* 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)
{
unsigned char *p;
if (s->state == a)
{
p=(unsigned char *)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;
if (s->version == DTLS1_BAD_VER) {
s->d1->next_handshake_write_seq++;
s2n(s->d1->handshake_write_seq,p);
s->init_num+=2;
}
s->init_off=0;
dtls1_set_message_header_int(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));
}