/* 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
* [email protected].
*
* 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>
/* XDTLS: figure out the right values */
static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
static unsigned int dtls1_min_mtu(void);
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 int dtls1_retransmit_buffered_messages(SSL *s);
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)
{
hm_fragment *frag = NULL;
unsigned char *buf = 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;
return frag;
}
static void
dtls1_hm_fragment_free(hm_fragment *frag)
{
if (frag->fragment) OPENSSL_free(frag->fragment);
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;
/* AHA! Figure out the MTU, and stick to the right size */
if ( ! (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);
}
OPENSSL_assert(mtu > 0); /* should have something reasonable now */
#endif
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);
frag_off = 0;
while( s->init_num)
{
curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
DTLS1_RT_HEADER_LENGTH;
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;
}
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;
/* write atleast DTLS1_HM_HEADER_LENGTH bytes */
if ( len <= DTLS1_HM_HEADER_LENGTH)
len += DTLS1_HM_HEADER_LENGTH;
}
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))
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->client_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;
/* 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;
do
{
if ( msg_hdr->frag_off == 0)
{
/* s->d1->r_message_header.msg_len = 0; */
memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
}
i = dtls1_get_message_fragment(s, st1, stn, max, ok);
if ( i == DTLS1_HM_BAD_FRAGMENT ||
i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
continue;
else if ( i <= 0 && !*ok)
return i;
/* Note that s->init_sum is used 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. Overlapping fragments would cause
* premature termination, so we don't expect overlaps.
* Well, handling overlaps would require something more
* drastic. Indeed, as it is now there is no way to
* tell if out-of-order fragment from the middle was
* the last. '>=' is the best/least we can do to control
* the potential damage caused by malformed overlaps. */
if ((unsigned int)s->init_num >= msg_hdr->msg_len)
{
unsigned char *p = (unsigned char *)s->init_buf->data;
unsigned long msg_len = msg_hdr->msg_len;
/* reconstruct message header as if it was
* sent in single fragment */
*(p++) = msg_hdr->type;
l2n3(msg_len,p);
s2n (msg_hdr->seq,p);
l2n3(0,p);
l2n3(msg_len,p);
if (s->client_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));
s->d1->handshake_read_seq++;
/* we just read a handshake message from the other side:
* this means that we don't need to retransmit of the
* buffered messages.
* XDTLS: may be able clear out this
* buffer a little sooner (i.e if an out-of-order
* handshake message/record is received at the record
* layer.
* XDTLS: exception is that the server needs to
* know that change cipher spec and finished messages
* have been received by the client before clearing this
* buffer. this can simply be done by waiting for the
* first data segment, but is there a better way? */
dtls1_clear_record_buffer(s);
s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
return s->init_num;
}
else
msg_hdr->frag_off = i;
} while(1) ;
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,(int)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;
if ( s->d1->handshake_read_seq == frag->msg_header.seq)
{
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->msg_header.frag_len;
}
ssl3_send_alert(s,SSL3_AL_FATAL,al);
s->init_num = 0;
*ok = 0;
return -1;
}
else
return 0;
}
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;
PQ_64BIT seq64;
unsigned long frag_len = msg_hdr->frag_len;
if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
goto err;
if (msg_hdr->seq <= s->d1->handshake_read_seq)
{
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;
}
}
frag = dtls1_hm_fragment_new(frag_len);
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;
}
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64, msg_hdr->seq);
item = pitem_new(seq64, frag);
pq_64bit_free(&seq64);
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 l, 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;
}
OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
/* 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
*/
if ( msg_hdr.seq != s->d1->handshake_read_seq)
return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
l = msg_hdr.msg_len;
frag_off = msg_hdr.frag_off;
frag_len = msg_hdr.frag_len;
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 */
OPENSSL_assert(i == (int)frag_len);
*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,
&(s->s3->finish_dgst1),
&(s->s3->finish_dgst2),
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;
#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->client_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));
}
unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
{
unsigned char *p;
int n,i;
unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
BUF_MEM *buf;
X509_STORE_CTX xs_ctx;
X509_OBJECT obj;
/* TLSv1 sends a chain with nothing in it, instead of an alert */
buf=s->init_buf;
if (!BUF_MEM_grow_clean(buf,10))
{
SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
return(0);
}
if (x != NULL)
{
if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
{
SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
return(0);
}
for (;;)
{
n=i2d_X509(x,NULL);
if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
{
SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
return(0);
}
p=(unsigned char *)&(buf->data[l]);
l2n3(n,p);
i2d_X509(x,&p);
l+=n+3;
if (X509_NAME_cmp(X509_get_subject_name(x),
X509_get_issuer_name(x)) == 0) break;
i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
X509_get_issuer_name(x),&obj);
if (i <= 0) break;
x=obj.data.x509;
/* Count is one too high since the X509_STORE_get uped the
* ref count */
X509_free(x);
}
X509_STORE_CTX_cleanup(&xs_ctx);
}
/* Thawte special :-) */
if (s->ctx->extra_certs != NULL)
for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
{
x=sk_X509_value(s->ctx->extra_certs,i);
n=i2d_X509(x,NULL);
if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
{
SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
return(0);
}
p=(unsigned char *)&(buf->data[l]);
l2n3(n,p);
i2d_X509(x,&p);
l+=n+3;
}
l-= (3 + DTLS1_HM_HEADER_LENGTH);
p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
l2n3(l,p);
l+=3;
p=(unsigned char *)&(buf->data[0]);
p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
l+=DTLS1_HM_HEADER_LENGTH;
return(l);
}
int dtls1_read_failed(SSL *s, int code)
{
DTLS1_STATE *state;
BIO *bio;
int send_alert = 0;
if ( code > 0)
{
fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
return 1;
}
bio = SSL_get_rbio(s);
if ( ! BIO_dgram_recv_timedout(bio))
{
/* 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;
}
state = s->d1;
state->timeout.num_alerts++;
if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
{
/* fail the connection, enough alerts have been sent */
SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
return 0;
}
state->timeout.read_timeouts++;
if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
{
send_alert = 1;
state->timeout.read_timeouts = 1;
}
#if 0 /* for now, each alert contains only one record number */
item = pqueue_peek(state->rcvd_records);
if ( item )
{
/* send an alert immediately for all the missing records */
}
else
#endif
#if 0 /* no more alert sending, just retransmit the last set of messages */
if ( send_alert)
ssl3_send_alert(s,SSL3_AL_WARNING,
DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
#endif
return dtls1_retransmit_buffered_messages(s) ;
}
static 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, frag->msg_header.seq, 0, &found) <= 0 &&
found)
{
fprintf(stderr, "dtls1_retransmit_message() failed\n");
return -1;
}
}
return 1;
}
int
dtls1_buffer_message(SSL *s, int is_ccs)
{
pitem *item;
hm_fragment *frag;
PQ_64BIT seq64;
unsigned int epoch = s->d1->w_epoch;
/* this function is called immediately after a message has
* been serialized */
OPENSSL_assert(s->init_off == 0);
frag = dtls1_hm_fragment_new(s->init_num);
memcpy(frag->fragment, s->init_buf->data, s->init_num);
if ( is_ccs)
{
OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
epoch++;
}
else
{
OPENSSL_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;
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64, epoch<<16 | frag->msg_header.seq);
item = pitem_new(seq64, frag);
pq_64bit_free(&seq64);
if ( item == NULL)
{
dtls1_hm_fragment_free(frag);
return 0;
}
#if 0
fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
#endif
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;
PQ_64BIT seq64;
/*
OPENSSL_assert(s->init_num == 0);
OPENSSL_assert(s->init_off == 0);
*/
/* XDTLS: the requested message ought to be found, otherwise error */
pq_64bit_init(&seq64);
pq_64bit_assign_word(&seq64, seq);
item = pqueue_find(s->d1->sent_messages, seq64);
pq_64bit_free(&seq64);
if ( item == NULL)
{
fprintf(stderr, "retransmit: message %d non-existant\n", seq);
*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->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_int(s, frag->msg_header.type,
frag->msg_header.msg_len, frag->msg_header.seq, 0,
frag->msg_header.frag_len);
s->d1->retransmitting = 1;
ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
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)
{
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);
}
}
unsigned char *
dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
unsigned long len, unsigned long frag_off, unsigned long frag_len)
{
if ( frag_off == 0)
{
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);
return p += DTLS1_HM_HEADER_LENGTH;
}
/* don't actually do the writing, wait till the MTU has been retrieved */
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)
{
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 unsigned char *
dtls1_write_message_header(SSL *s, unsigned char *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;
}
static 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)
{
size_t 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;
}
void
dtls1_get_message_header(unsigned char *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);
}
void
dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
{
memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
ccs_hdr->type = *(data++);
}
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