/* ssl/d1_both.c */

/* 

 * 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.]

 */

/*

 © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 */

#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 */

#ifdef EMULATOR

static const unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};

#else

static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};

#endif

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)

        {