/* ssl/d1_pkt.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.]

  */

 #include <stdio.h>

 #include <errno.h>

 #define USE_SOCKETS

 #include "ssl_locl.h"

 #include <openssl/evp.h>

 #include <openssl/buffer.h>

 #include <openssl/pqueue.h>

 #include <openssl/rand.h>

 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 

 	int len, int peek);

 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,

 	PQ_64BIT *seq_num);

 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);

 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 

     unsigned int *is_next_epoch);

 #if 0

 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,

 	unsigned short *priority, unsigned long *offset);

 #endif

 static int dtls1_buffer_record(SSL *s, record_pqueue *q,

 	PQ_64BIT priority);

 static int dtls1_process_record(SSL *s);

 #if PQ_64BIT_IS_INTEGER

 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);

 #endif

 static void dtls1_clear_timeouts(SSL *s);

 /* copy buffered record into SSL structure */

 static int

 dtls1_copy_record(SSL *s, pitem *item)

     {

     DTLS1_RECORD_DATA *rdata;

     rdata = (DTLS1_RECORD_DATA *)item->data;

     if (s->s3->rbuf.buf != NULL)

         OPENSSL_free(s->s3->rbuf.buf);

     s->packet = rdata->packet;

     s->packet_length = rdata->packet_length;

     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));

     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));

     return(1);

     }

 static int

 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)

 {

     DTLS1_RECORD_DATA *rdata;

 	pitem *item;

 	rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));

 	item = pitem_new(priority, rdata);

 	if (rdata == NULL || item == NULL)

 		{

 		if (rdata != NULL) OPENSSL_free(rdata);

 		if (item != NULL) pitem_free(item);

 		SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);

 		return(0);

 		}

 	rdata->packet = s->packet;

 	rdata->packet_length = s->packet_length;

 	memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));

 	memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));

 	item->data = rdata;

 	/* insert should not fail, since duplicates are dropped */

 	if (pqueue_insert(queue->q, item) == NULL)

 		{

 		OPENSSL_free(rdata);

 		pitem_free(item);

 		return(0);

 		}

 	s->packet = NULL;

 	s->packet_length = 0;

 	memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));

 	memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));

 	if (!ssl3_setup_buffers(s))

 		{

 		SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);

 		OPENSSL_free(rdata);

 		pitem_free(item);

 		return(0);

 		}

 	return(1);

     }

 static int

 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)

     {

     pitem *item;

     item = pqueue_pop(queue->q);

     if (item)

         {

         dtls1_copy_record(s, item);

         OPENSSL_free(item->data);

 		pitem_free(item);

         return(1);

         }

     return(0);

     }

 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 

  * yet */

 #define dtls1_get_unprocessed_record(s) \

                    dtls1_retrieve_buffered_record((s), \

                    &((s)->d1->unprocessed_rcds))

 /* retrieve a buffered record that belongs to the current epoch, ie, processed */

 #define dtls1_get_processed_record(s) \

                    dtls1_retrieve_buffered_record((s), \

                    &((s)->d1->processed_rcds))

 static int

 dtls1_process_buffered_records(SSL *s)

     {

     pitem *item;

     item = pqueue_peek(s->d1->unprocessed_rcds.q);

     if (item)

         {

         DTLS1_RECORD_DATA *rdata;

         rdata = (DTLS1_RECORD_DATA *)item->data;

         /* Check if epoch is current. */

         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)

             return(1);  /* Nothing to do. */

         /* Process all the records. */

         while (pqueue_peek(s->d1->unprocessed_rcds.q))

             {

             dtls1_get_unprocessed_record(s);

             if ( ! dtls1_process_record(s))

                 return(0);

             dtls1_buffer_record(s, &(s->d1->processed_rcds), 

                 s->s3->rrec.seq_num);

             }

         }

     /* sync epoch numbers once all the unprocessed records 

      * have been processed */

     s->d1->processed_rcds.epoch = s->d1->r_epoch;

     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;

     return(1);

     }

 #if 0

 static int

 dtls1_get_buffered_record(SSL *s)

 	{

 	pitem *item;

 	PQ_64BIT priority = 

 		(((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 

 		((PQ_64BIT)s->d1->r_msg_hdr.frag_off);

 	if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 

 							   nothing buffered */

 		return 0;

 	item = pqueue_peek(s->d1->rcvd_records);

 	if (item && item->priority == priority)

 		{

 		/* Check if we've received the record of interest.  It must be

 		 * a handshake record, since data records as passed up without

 		 * buffering */

 		DTLS1_RECORD_DATA *rdata;

 		item = pqueue_pop(s->d1->rcvd_records);

 		rdata = (DTLS1_RECORD_DATA *)item->data;

 		if (s->s3->rbuf.buf != NULL)

 			OPENSSL_free(s->s3->rbuf.buf);

 		s->packet = rdata->packet;

 		s->packet_length = rdata->packet_length;

 		memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));

 		memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));

 		OPENSSL_free(item->data);

 		pitem_free(item);

 		/* s->d1->next_expected_seq_num++; */

 		return(1);

 		}

 	return 0;

 	}

 #endif

 static int

 dtls1_process_record(SSL *s)

 {

     int i,al;

 	int clear=0;

     int enc_err;

 	SSL_SESSION *sess;

     SSL3_RECORD *rr;

 	unsigned int mac_size;

 	unsigned char md[EVP_MAX_MD_SIZE];

 	rr= &(s->s3->rrec);

     sess = s->session;

 	/* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,

 	 * and we have that many bytes in s->packet

 	 */

 	rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);

 	/* ok, we can now read from 's->packet' data into 'rr'

 	 * rr->input points at rr->length bytes, which

 	 * need to be copied into rr->data by either

 	 * the decryption or by the decompression

 	 * When the data is 'copied' into the rr->data buffer,

 	 * rr->input will be pointed at the new buffer */ 

 	/* We now have - encrypted [ MAC [ compressed [ plain ] ] ]

 	 * rr->length bytes of encrypted compressed stuff. */

 	/* check is not needed I believe */

 	if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)

 		{

 		al=SSL_AD_RECORD_OVERFLOW;

 		SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);

 		goto f_err;

 		}

 	/* decrypt in place in 'rr->input' */

 	rr->data=rr->input;

 	enc_err = s->method->ssl3_enc->enc(s,0);

 	if (enc_err <= 0)

 		{

 		if (enc_err == 0)

 			/* SSLerr() and ssl3_send_alert() have been called */

 			goto err;

 		/* otherwise enc_err == -1 */

 		goto decryption_failed_or_bad_record_mac;

 		}

 #ifdef TLS_DEBUG

 printf("dec %d\n",rr->length);

 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }

 printf("\n");

 #endif

 	/* r->length is now the compressed data plus mac */

 if (	(sess == NULL) ||

 		(s->enc_read_ctx == NULL) ||

 		(s->read_hash == NULL))

     clear=1;

 	if (!clear)

 		{

 		mac_size=EVP_MD_size(s->read_hash);

 		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)

 			{

 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */

 			al=SSL_AD_RECORD_OVERFLOW;

 			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);

 			goto f_err;

 #else

 			goto decryption_failed_or_bad_record_mac;

 #endif			

 			}

 		/* check the MAC for rr->input (it's in mac_size bytes at the tail) */

 		if (rr->length < mac_size)

 			{

 #if 0 /* OK only for stream ciphers */

 			al=SSL_AD_DECODE_ERROR;

 			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);

 			goto f_err;

 #else

 			goto decryption_failed_or_bad_record_mac;

 #endif

 			}

 		rr->length-=mac_size;

 		i=s->method->ssl3_enc->mac(s,md,0);

 		if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)

 			{

 			goto decryption_failed_or_bad_record_mac;

 			}

 		}

 	/* r->length is now just compressed */

 	if (s->expand != NULL)

 		{

 		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)

 			{

 			al=SSL_AD_RECORD_OVERFLOW;

 			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);

 			goto f_err;

 			}

 		if (!ssl3_do_uncompress(s))

 			{

 			al=SSL_AD_DECOMPRESSION_FAILURE;

 			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);

 			goto f_err;

 			}

 		}

 	if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)

 		{

 		al=SSL_AD_RECORD_OVERFLOW;

 		SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);

 		goto f_err;

 		}

 	rr->off=0;

 	/* So at this point the following is true

 	 * ssl->s3->rrec.type 	is the type of record

 	 * ssl->s3->rrec.length	== number of bytes in record

 	 * ssl->s3->rrec.off	== offset to first valid byte

 	 * ssl->s3->rrec.data	== where to take bytes from, increment

 	 *			   after use :-).

 	 */

 	/* we have pulled in a full packet so zero things */

 	s->packet_length=0;

     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */

     return(1);

 decryption_failed_or_bad_record_mac:

 	/* Separate 'decryption_failed' alert was introduced with TLS 1.0,

 	 * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption

 	 * failure is directly visible from the ciphertext anyway,

 	 * we should not reveal which kind of error occured -- this

 	 * might become visible to an attacker (e.g. via logfile) */

 	al=SSL_AD_BAD_RECORD_MAC;

 	SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);

 f_err:

 	ssl3_send_alert(s,SSL3_AL_FATAL,al);

 err:

 	return(0);

 }

 /* Call this to get a new input record.

  * It will return <= 0 if more data is needed, normally due to an error

  * or non-blocking IO.

  * When it finishes, one packet has been decoded and can be found in

  * ssl->s3->rrec.type    - is the type of record

  * ssl->s3->rrec.data, 	 - data

  * ssl->s3->rrec.length, - number of bytes

  */

 /* used only by dtls1_read_bytes */

 int dtls1_get_record(SSL *s)

 	{

 	int ssl_major,ssl_minor,al;

 	int i,n;

 	SSL3_RECORD *rr;

 	SSL_SESSION *sess;

 	unsigned char *p;

 	unsigned short version;

 	DTLS1_BITMAP *bitmap;

 	unsigned int is_next_epoch;

 	rr= &(s->s3->rrec);

 	sess=s->session;

     /* The epoch may have changed.  If so, process all the

      * pending records.  This is a non-blocking operation. */

     if ( ! dtls1_process_buffered_records(s))

         return 0;

 	/* if we're renegotiating, then there may be buffered records */

 	if (dtls1_get_processed_record(s))

 		return 1;

 	/* get something from the wire */

 again:

 	/* check if we have the header */

 	if (	(s->rstate != SSL_ST_READ_BODY) ||

 		(s->packet_length < DTLS1_RT_HEADER_LENGTH)) 

 		{

 		n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);

 		/* read timeout is handled by dtls1_read_bytes */

 		if (n <= 0) return(n); /* error or non-blocking */

 		OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);

 		s->rstate=SSL_ST_READ_BODY;

 		p=s->packet;

 		/* Pull apart the header into the DTLS1_RECORD */

 		rr->type= *(p++);

 		ssl_major= *(p++);

 		ssl_minor= *(p++);

 		version=(ssl_major<<8)|ssl_minor;

 		/* sequence number is 64 bits, with top 2 bytes = epoch */ 

 		n2s(p,rr->epoch);

 		memcpy(&(s->s3->read_sequence[2]), p, 6);

 		p+=6;

 		n2s(p,rr->length);

 		/* Lets check version */

 		if (!s->first_packet)

 			{

 			if (version != s->version && version != DTLS1_BAD_VER)

 				{

 				SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);

 				/* Send back error using their

 				 * version number :-) */

 				s->version=version;

 				al=SSL_AD_PROTOCOL_VERSION;

 				goto f_err;

 				}

 			}

 		if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&

 		    (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))

 			{

 			SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);

 			goto err;

 			}

 		if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)

 			{

 			al=SSL_AD_RECORD_OVERFLOW;

 			SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);

 			goto f_err;

 			}

 		s->client_version = version;

 		/* now s->rstate == SSL_ST_READ_BODY */

 		}

 	/* s->rstate == SSL_ST_READ_BODY, get and decode the data */

 	if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)

 		{

 		/* now s->packet_length == DTLS1_RT_HEADER_LENGTH */

 		i=rr->length;

 		n=ssl3_read_n(s,i,i,1);

 		if (n <= 0) return(n); /* error or non-blocking io */

 		/* this packet contained a partial record, dump it */

 		if ( n != i)

 			{

 			s->packet_length = 0;

 			goto again;

 			}

 		/* now n == rr->length,

 		 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */

 		}

 	s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */

 	/* match epochs.  NULL means the packet is dropped on the floor */

 	bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);

 	if ( bitmap == NULL)

         {

         s->packet_length = 0;  /* dump this record */

         goto again;   /* get another record */

 		}

 	/* check whether this is a repeat, or aged record */

 	if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))

 		{

 		s->packet_length=0; /* dump this record */

 		goto again;     /* get another record */

 		}

 	/* just read a 0 length packet */

 	if (rr->length == 0) goto again;

     /* If this record is from the next epoch (either HM or ALERT), buffer it

      * since it cannot be processed at this time.

      * Records from the next epoch are marked as received even though they are 

      * not processed, so as to prevent any potential resource DoS attack */

     if (is_next_epoch)

         {

         dtls1_record_bitmap_update(s, bitmap);

         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);

         s->packet_length = 0;

         goto again;

         }

     if ( ! dtls1_process_record(s))

         return(0);

 	dtls1_clear_timeouts(s);  /* done waiting */

 	return(1);

 f_err:

 	ssl3_send_alert(s,SSL3_AL_FATAL,al);

 err:

 	return(0);

 	}

 /* Return up to 'len' payload bytes received in 'type' records.

  * 'type' is one of the following:

  *

  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)

  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)

  *   -  0 (during a shutdown, no data has to be returned)

  *

  * If we don't have stored data to work from, read a SSL/TLS record first

  * (possibly multiple records if we still don't have anything to return).

  *

  * This function must handle any surprises the peer may have for us, such as

  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really

  * a surprise, but handled as if it were), or renegotiation requests.

  * Also if record payloads contain fragments too small to process, we store

  * them until there is enough for the respective protocol (the record protocol

  * may use arbitrary fragmentation and even interleaving):

  *     Change cipher spec protocol

  *             just 1 byte needed, no need for keeping anything stored

  *     Alert protocol

  *             2 bytes needed (AlertLevel, AlertDescription)

  *     Handshake protocol

  *             4 bytes needed (HandshakeType, uint24 length) -- we just have

  *             to detect unexpected Client Hello and Hello Request messages

  *             here, anything else is handled by higher layers

  *     Application data protocol

  *             none of our business

  */

 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)

 	{

 	int al,i,j,ret;

 	unsigned int n;

 	SSL3_RECORD *rr;

 	void (*cb)(const SSL *ssl,int type2,int val)=NULL;

 	if (s->s3->rbuf.buf == NULL) /* Not initialized yet */

 		if (!ssl3_setup_buffers(s))

 			return(-1);

     /* XXX: check what the second '&& type' is about */

 	if ((type && (type != SSL3_RT_APPLICATION_DATA) && 

 		(type != SSL3_RT_HANDSHAKE) && type) ||

 	    (peek && (type != SSL3_RT_APPLICATION_DATA)))

 		{

 		SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);

 		return -1;

 		}

 	/* check whether there's a handshake message (client hello?) waiting */

 	if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))

 		return ret;

 	/* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */

 	if (!s->in_handshake && SSL_in_init(s))

 		{

 		/* type == SSL3_RT_APPLICATION_DATA */

 		i=s->handshake_func(s);

 		if (i < 0) return(i);

 		if (i == 0)

 			{

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);

 			return(-1);

 			}

 		}

 start:

 	s->rwstate=SSL_NOTHING;

 	/* s->s3->rrec.type	    - is the type of record

 	 * s->s3->rrec.data,    - data

 	 * s->s3->rrec.off,     - offset into 'data' for next read

 	 * s->s3->rrec.length,  - number of bytes. */

 	rr = &(s->s3->rrec);

 	/* get new packet if necessary */

 	if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))

 		{

 		ret=dtls1_get_record(s);

 		if (ret <= 0) 

 			{

 			ret = dtls1_read_failed(s, ret);

 			/* anything other than a timeout is an error */

 			if (ret <= 0)  

 				return(ret);

 			else

 				goto start;

 			}

 		}

 	/* we now have a packet which can be read and processed */

 	if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,

 	                               * reset by ssl3_get_finished */

 		&& (rr->type != SSL3_RT_HANDSHAKE))

 		{

 		al=SSL_AD_UNEXPECTED_MESSAGE;

 		SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);

 		goto err;

 		}

 	/* If the other end has shut down, throw anything we read away

 	 * (even in 'peek' mode) */

 	if (s->shutdown & SSL_RECEIVED_SHUTDOWN)

 		{

 		rr->length=0;

 		s->rwstate=SSL_NOTHING;

 		return(0);

 		}

 	if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */

 		{

 		/* make sure that we are not getting application data when we

 		 * are doing a handshake for the first time */

 		if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&

 			(s->enc_read_ctx == NULL))

 			{

 			al=SSL_AD_UNEXPECTED_MESSAGE;

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);

 			goto f_err;

 			}

 		if (len <= 0) return(len);

 		if ((unsigned int)len > rr->length)

 			n = rr->length;

 		else

 			n = (unsigned int)len;

 		memcpy(buf,&(rr->data[rr->off]),n);

 		if (!peek)

 			{

 			rr->length-=n;

 			rr->off+=n;

 			if (rr->length == 0)

 				{

 				s->rstate=SSL_ST_READ_HEADER;

 				rr->off=0;

 				}

 			}

 		return(n);

 		}

 	/* If we get here, then type != rr->type; if we have a handshake

 	 * message, then it was unexpected (Hello Request or Client Hello). */

 	/* In case of record types for which we have 'fragment' storage,

 	 * fill that so that we can process the data at a fixed place.

 	 */

 		{

 		unsigned int k, dest_maxlen = 0;

 		unsigned char *dest = NULL;

 		unsigned int *dest_len = NULL;

 		if (rr->type == SSL3_RT_HANDSHAKE)

 			{

 			dest_maxlen = sizeof s->d1->handshake_fragment;

 			dest = s->d1->handshake_fragment;

 			dest_len = &s->d1->handshake_fragment_len;

 			}

 		else if (rr->type == SSL3_RT_ALERT)

 			{

 			dest_maxlen = sizeof(s->d1->alert_fragment);

 			dest = s->d1->alert_fragment;

 			dest_len = &s->d1->alert_fragment_len;

 			}

                 /* else it's a CCS message, or it's wrong */

                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)

                         {

                           /* Not certain if this is the right error handling */

                           al=SSL_AD_UNEXPECTED_MESSAGE;

                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);

                           goto f_err;

                         }

 		if (dest_maxlen > 0)

 			{

             /* XDTLS:  In a pathalogical case, the Client Hello

              *  may be fragmented--don't always expect dest_maxlen bytes */

 			if ( rr->length < dest_maxlen)

 				{

 				s->rstate=SSL_ST_READ_HEADER;

 				rr->length = 0;

 				goto start;

 				}

 			/* now move 'n' bytes: */

 			for ( k = 0; k < dest_maxlen; k++)

 				{

 				dest[k] = rr->data[rr->off++];

 				rr->length--;

 				}

 			*dest_len = dest_maxlen;

 			}

 		}

 	/* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;

 	 * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.

 	 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */

 	/* If we are a client, check for an incoming 'Hello Request': */

 	if ((!s->server) &&

 		(s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&

 		(s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&

 		(s->session != NULL) && (s->session->cipher != NULL))

 		{

 		s->d1->handshake_fragment_len = 0;

 		if ((s->d1->handshake_fragment[1] != 0) ||

 			(s->d1->handshake_fragment[2] != 0) ||

 			(s->d1->handshake_fragment[3] != 0))

 			{

 			al=SSL_AD_DECODE_ERROR;

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);

 			goto err;

 			}

 		/* no need to check sequence number on HELLO REQUEST messages */

 		if (s->msg_callback)

 			s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 

 				s->d1->handshake_fragment, 4, s, s->msg_callback_arg);

 		if (SSL_is_init_finished(s) &&

 			!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&

 			!s->s3->renegotiate)

 			{

 			ssl3_renegotiate(s);

 			if (ssl3_renegotiate_check(s))

 				{

 				i=s->handshake_func(s);

 				if (i < 0) return(i);

 				if (i == 0)

 					{

 					SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);

 					return(-1);

 					}

 				if (!(s->mode & SSL_MODE_AUTO_RETRY))

 					{

 					if (s->s3->rbuf.left == 0) /* no read-ahead left? */

 						{

 						BIO *bio;

 						/* In the case where we try to read application data,

 						 * but we trigger an SSL handshake, we return -1 with

 						 * the retry option set.  Otherwise renegotiation may

 						 * cause nasty problems in the blocking world */

 						s->rwstate=SSL_READING;

 						bio=SSL_get_rbio(s);

 						BIO_clear_retry_flags(bio);

 						BIO_set_retry_read(bio);

 						return(-1);

 						}

 					}

 				}

 			}

 		/* we either finished a handshake or ignored the request,

 		 * now try again to obtain the (application) data we were asked for */

 		goto start;

 		}

 	if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)

 		{

 		int alert_level = s->d1->alert_fragment[0];

 		int alert_descr = s->d1->alert_fragment[1];

 		s->d1->alert_fragment_len = 0;

 		if (s->msg_callback)

 			s->msg_callback(0, s->version, SSL3_RT_ALERT, 

 				s->d1->alert_fragment, 2, s, s->msg_callback_arg);

 		if (s->info_callback != NULL)

 			cb=s->info_callback;

 		else if (s->ctx->info_callback != NULL)

 			cb=s->ctx->info_callback;

 		if (cb != NULL)

 			{

 			j = (alert_level << 8) | alert_descr;

 			cb(s, SSL_CB_READ_ALERT, j);

 			}

 		if (alert_level == 1) /* warning */

 			{

 			s->s3->warn_alert = alert_descr;

 			if (alert_descr == SSL_AD_CLOSE_NOTIFY)

 				{

 				s->shutdown |= SSL_RECEIVED_SHUTDOWN;

 				return(0);

 				}

 #if 0

             /* XXX: this is a possible improvement in the future */

 			/* now check if it's a missing record */

 			if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)

 				{

 				unsigned short seq;

 				unsigned int frag_off;

 				unsigned char *p = &(s->d1->alert_fragment[2]);

 				n2s(p, seq);

 				n2l3(p, frag_off);

 				dtls1_retransmit_message(s, seq, frag_off, &found);

 				if ( ! found  && SSL_in_init(s))

 					{

 					/* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */

 					/* requested a message not yet sent, 

 					   send an alert ourselves */

 					ssl3_send_alert(s,SSL3_AL_WARNING,

 						DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);

 					}

 				}

 #endif

 			}

 		else if (alert_level == 2) /* fatal */

 			{

 			char tmp[16];

 			s->rwstate=SSL_NOTHING;

 			s->s3->fatal_alert = alert_descr;

 			SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);

 			BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);

 			ERR_add_error_data(2,"SSL alert number ",tmp);

 			s->shutdown|=SSL_RECEIVED_SHUTDOWN;

 			SSL_CTX_remove_session(s->ctx,s->session);

 			return(0);

 			}

 		else

 			{

 			al=SSL_AD_ILLEGAL_PARAMETER;

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);

 			goto f_err;

 			}

 		goto start;

 		}

 	if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */

 		{

 		s->rwstate=SSL_NOTHING;

 		rr->length=0;

 		return(0);

 		}

 	if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)

 		{

 		struct ccs_header_st ccs_hdr;

 		dtls1_get_ccs_header(rr->data, &ccs_hdr);

 		/* 'Change Cipher Spec' is just a single byte, so we know

 		 * exactly what the record payload has to look like */

 		/* XDTLS: check that epoch is consistent */

 		if (	(s->client_version == DTLS1_BAD_VER && rr->length != 3) ||

 			(s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) || 

 			(rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))

 			{

 			i=SSL_AD_ILLEGAL_PARAMETER;

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);

 			goto err;

 			}

 		rr->length=0;

 		if (s->msg_callback)

 			s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 

 				rr->data, 1, s, s->msg_callback_arg);

 		s->s3->change_cipher_spec=1;

 		if (!ssl3_do_change_cipher_spec(s))

 			goto err;

 		/* do this whenever CCS is processed */

 		dtls1_reset_seq_numbers(s, SSL3_CC_READ);

 		if (s->client_version == DTLS1_BAD_VER)

 			s->d1->handshake_read_seq++;

 		goto start;

 		}

 	/* Unexpected handshake message (Client Hello, or protocol violation) */

 	if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 

 		!s->in_handshake)

 		{

 		struct hm_header_st msg_hdr;

 		/* this may just be a stale retransmit */

 		dtls1_get_message_header(rr->data, &msg_hdr);

 		if( rr->epoch != s->d1->r_epoch)

 			{

 			rr->length = 0;

 			goto start;

 			}

 		if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&

 			!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))

 			{

 #if 0 /* worked only because C operator preferences are not as expected (and

        * because this is not really needed for clients except for detecting

        * protocol violations): */

 			s->state=SSL_ST_BEFORE|(s->server)

 				?SSL_ST_ACCEPT

 				:SSL_ST_CONNECT;

 #else

 			s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;

 #endif

 			s->new_session=1;

 			}

 		i=s->handshake_func(s);

 		if (i < 0) return(i);

 		if (i == 0)

 			{

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);

 			return(-1);

 			}

 		if (!(s->mode & SSL_MODE_AUTO_RETRY))

 			{

 			if (s->s3->rbuf.left == 0) /* no read-ahead left? */

 				{

 				BIO *bio;

 				/* In the case where we try to read application data,

 				 * but we trigger an SSL handshake, we return -1 with

 				 * the retry option set.  Otherwise renegotiation may

 				 * cause nasty problems in the blocking world */

 				s->rwstate=SSL_READING;

 				bio=SSL_get_rbio(s);

 				BIO_clear_retry_flags(bio);

 				BIO_set_retry_read(bio);

 				return(-1);

 				}

 			}

 		goto start;

 		}

 	switch (rr->type)

 		{

 	default:

 #ifndef OPENSSL_NO_TLS

 		/* TLS just ignores unknown message types */

 		if (s->version == TLS1_VERSION)

 			{

 			rr->length = 0;

 			goto start;

 			}

 #endif

 		al=SSL_AD_UNEXPECTED_MESSAGE;

 		SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);

 		goto f_err;

 	case SSL3_RT_CHANGE_CIPHER_SPEC:

 	case SSL3_RT_ALERT:

 	case SSL3_RT_HANDSHAKE:

 		/* we already handled all of these, with the possible exception

 		 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that

 		 * should not happen when type != rr->type */

 		al=SSL_AD_UNEXPECTED_MESSAGE;

 		SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);

 		goto f_err;

 	case SSL3_RT_APPLICATION_DATA:

 		/* At this point, we were expecting handshake data,

 		 * but have application data.  If the library was

 		 * running inside ssl3_read() (i.e. in_read_app_data

 		 * is set) and it makes sense to read application data

 		 * at this point (session renegotiation not yet started),

 		 * we will indulge it.

 		 */

 		if (s->s3->in_read_app_data &&

 			(s->s3->total_renegotiations != 0) &&

 			((

 				(s->state & SSL_ST_CONNECT) &&

 				(s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&

 				(s->state <= SSL3_ST_CR_SRVR_HELLO_A)

 				) || (

 					(s->state & SSL_ST_ACCEPT) &&

 					(s->state <= SSL3_ST_SW_HELLO_REQ_A) &&

 					(s->state >= SSL3_ST_SR_CLNT_HELLO_A)

 					)

 				))

 			{

 			s->s3->in_read_app_data=2;

 			return(-1);

 			}

 		else

 			{

 			al=SSL_AD_UNEXPECTED_MESSAGE;

 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);

 			goto f_err;

 			}

 		}

 	/* not reached */

 f_err:

 	ssl3_send_alert(s,SSL3_AL_FATAL,al);

 err:

 	return(-1);

 	}

 int

 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)

 	{

 	unsigned int n,tot;

 	int i;

 	if (SSL_in_init(s) && !s->in_handshake)

 		{

 		i=s->handshake_func(s);

 		if (i < 0) return(i);

 		if (i == 0)

 			{

 			SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);

 			return -1;

 			}

 		}

 	tot = s->s3->wnum;

 	n = len - tot;

 	while( n)

 		{

 		/* dtls1_write_bytes sends one record at a time, sized according to 

 		 * the currently known MTU */

 		i = dtls1_write_bytes(s, type, buf_, len);

 		if (i <= 0) return i;

 		if ((i == (int)n) ||

 			(type == SSL3_RT_APPLICATION_DATA &&

 				(s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))

 			{

 			/* next chunk of data should get another prepended empty fragment

 			 * in ciphersuites with known-IV weakness: */

 			s->s3->empty_fragment_done = 0;

 			return tot+i;

 			}

 		tot += i;

 		n-=i;

 		}

 	return tot;

 	}

 	/* this only happens when a client hello is received and a handshake 

 	 * is started. */

 static int

 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 

 	int len, int peek)

 	{

 	if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))

 		/* (partially) satisfy request from storage */

 		{

 		unsigned char *src = s->d1->handshake_fragment;

 		unsigned char *dst = buf;

 		unsigned int k,n;

 		/* peek == 0 */

 		n = 0;

 		while ((len > 0) && (s->d1->handshake_fragment_len > 0))

 			{

 			*dst++ = *src++;

 			len--; s->d1->handshake_fragment_len--;

 			n++;

 			}

 		/* move any remaining fragment bytes: */

 		for (k = 0; k < s->d1->handshake_fragment_len; k++)

 			s->d1->handshake_fragment[k] = *src++;

 		return n;

 		}

 	return 0;

 	}

 /* Call this to write data in records of type 'type'

  * It will return <= 0 if not all data has been sent or non-blocking IO.

  */

 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)

 	{

 	const unsigned char *buf=buf_;

 	unsigned int tot,n,nw;

 	int i;

 	unsigned int mtu;

 	s->rwstate=SSL_NOTHING;

 	tot=s->s3->wnum;

 	n=(len-tot);

 	/* handshake layer figures out MTU for itself, but data records

 	 * are also sent through this interface, so need to figure out MTU */

 #if 0

 	mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);

 	mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */

 #endif

 	mtu = s->d1->mtu;

 	if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)

 		mtu = SSL3_RT_MAX_PLAIN_LENGTH;

 	if (n > mtu)

 		nw=mtu;

 	else

 		nw=n;

 	i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);

 	if (i <= 0)

 		{

 		s->s3->wnum=tot;

 		return i;

 		}

 	if ( (int)s->s3->wnum + i == len)

 		s->s3->wnum = 0;

 	else 

 		s->s3->wnum += i;

 	return tot + i;

 	}

 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)

 	{

 	unsigned char *p,*pseq;

 	int i,mac_size,clear=0;

 	int prefix_len = 0;

 	SSL3_RECORD *wr;

 	SSL3_BUFFER *wb;

 	SSL_SESSION *sess;

 	int bs;

 	/* first check if there is a SSL3_BUFFER still being written

 	 * out.  This will happen with non blocking IO */

 	if (s->s3->wbuf.left != 0)

 		{

 		OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */

 		return(ssl3_write_pending(s,type,buf,len));

 		}

 	/* If we have an alert to send, lets send it */

 	if (s->s3->alert_dispatch)

 		{

 		i=s->method->ssl_dispatch_alert(s);

 		if (i <= 0)

 			return(i);

 		/* if it went, fall through and send more stuff */

 		}

 	if (len == 0 && !create_empty_fragment)

 		return 0;

 	wr= &(s->s3->wrec);

 	wb= &(s->s3->wbuf);

 	sess=s->session;

 	if (	(sess == NULL) ||

 		(s->enc_write_ctx == NULL) ||

 		(s->write_hash == NULL))

 		clear=1;

 	if (clear)

 		mac_size=0;

 	else

 		mac_size=EVP_MD_size(s->write_hash);

 	/* DTLS implements explicit IV, so no need for empty fragments */

 #if 0

 	/* 'create_empty_fragment' is true only when this function calls itself */

 	if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done

 		&& SSL_version(s) != DTLS1_VERSION)

 		{

 		/* countermeasure against known-IV weakness in CBC ciphersuites

 		 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 

 		 */

 		if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)

 			{

 			/* recursive function call with 'create_empty_fragment' set;

 			 * this prepares and buffers the data for an empty fragment

 			 * (these 'prefix_len' bytes are sent out later

 			 * together with the actual payload) */

 			prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);

 			if (prefix_len <= 0)

 				goto err;

 			if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)

 				{

 				/* insufficient space */

 				SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);

 				goto err;

 				}

 			}

 		s->s3->empty_fragment_done = 1;

 		}

 #endif

 	p = wb->buf + prefix_len;

 	/* write the header */

 	*(p++)=type&0xff;

 	wr->type=type;

 	if (s->client_version == DTLS1_BAD_VER)

 		*(p++) = DTLS1_BAD_VER>>8,

 		*(p++) = DTLS1_BAD_VER&0xff;

 	else

 		*(p++)=(s->version>>8),

 		*(p++)=s->version&0xff;

 	/* field where we are to write out packet epoch, seq num and len */

 	pseq=p; 

 	p+=10;

 	/* lets setup the record stuff. */

 	/* Make space for the explicit IV in case of CBC.

 	 * (this is a bit of a boundary violation, but what the heck).

 	 */

 	if ( s->enc_write_ctx && 

 		(EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))

 		bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);

 	else

 		bs = 0;

 	wr->data=p + bs;  /* make room for IV in case of CBC */

 	wr->length=(int)len;

 	wr->input=(unsigned char *)buf;

 	/* we now 'read' from wr->input, wr->length bytes into

 	 * wr->data */

 	/* first we compress */

 	if (s->compress != NULL)

 		{

 		if (!ssl3_do_compress(s))

 			{

 			SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);

 			goto err;

 			}

 		}

 	else

 		{

 		memcpy(wr->data,wr->input,wr->length);

 		wr->input=wr->data;

 		}

 	/* we should still have the output to wr->data and the input

 	 * from wr->input.  Length should be wr->length.

 	 * wr->data still points in the wb->buf */

 	if (mac_size != 0)

 		{

 		s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);

 		wr->length+=mac_size;

 		}

 	/* this is true regardless of mac size */

 	wr->input=p;

 	wr->data=p;

 	/* ssl3_enc can only have an error on read */

 	if (bs)	/* bs != 0 in case of CBC */

 		{

 		RAND_pseudo_bytes(p,bs);

 		/* master IV and last CBC residue stand for

 		 * the rest of randomness */

 		wr->length += bs;

 		}

 	s->method->ssl3_enc->enc(s,1);

 	/* record length after mac and block padding */

 /*	if (type == SSL3_RT_APPLICATION_DATA ||

 	(type == SSL3_RT_ALERT && ! SSL_in_init(s))) */

 	/* there's only one epoch between handshake and app data */

 	s2n(s->d1->w_epoch, pseq);

 	/* XDTLS: ?? */

 /*	else

 	s2n(s->d1->handshake_epoch, pseq); */

 	memcpy(pseq, &(s->s3->write_sequence[2]), 6);

 	pseq+=6;

 	s2n(wr->length,pseq);

 	/* we should now have

 	 * wr->data pointing to the encrypted data, which is

 	 * wr->length long */

 	wr->type=type; /* not needed but helps for debugging */

 	wr->length+=DTLS1_RT_HEADER_LENGTH;

 #if 0  /* this is now done at the message layer */

 	/* buffer the record, making it easy to handle retransmits */

 	if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)

 		dtls1_buffer_record(s, wr->data, wr->length, 

 			*((PQ_64BIT *)&(s->s3->write_sequence[0])));

 #endif

 	ssl3_record_sequence_update(&(s->s3->write_sequence[0]));

 	if (create_empty_fragment)

 		{

 		/* we are in a recursive call;

 		 * just return the length, don't write out anything here

 		 */

 		return wr->length;

 		}

 	/* now let's set up wb */

 	wb->left = prefix_len + wr->length;

 	wb->offset = 0;

 	/* memorize arguments so that ssl3_write_pending can detect bad write retries later */

 	s->s3->wpend_tot=len;

 	s->s3->wpend_buf=buf;

 	s->s3->wpend_type=type;

 	s->s3->wpend_ret=len;

 	/* we now just need to write the buffer */

 	return ssl3_write_pending(s,type,buf,len);

 err:

 	return -1;

 	}

 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,

 	PQ_64BIT *seq_num)

 	{

 #if PQ_64BIT_IS_INTEGER

 	PQ_64BIT mask = 0x0000000000000001L;

 #endif

 	PQ_64BIT rcd_num, tmp;

 	pq_64bit_init(&rcd_num);

 	pq_64bit_init(&tmp);

 	/* this is the sequence number for the record just read */

 	pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);

 	if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||

 		pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))

 		{

 		pq_64bit_assign(seq_num, &rcd_num);

 		pq_64bit_free(&rcd_num);

 		pq_64bit_free(&tmp);

 		return 1;  /* this record is new */

 		}

 	pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);

 	if ( pq_64bit_get_word(&tmp) > bitmap->length)

 		{

 		pq_64bit_free(&rcd_num);

 		pq_64bit_free(&tmp);

 		return 0;  /* stale, outside the window */

 		}

 #if PQ_64BIT_IS_BIGNUM

 	{

 	int offset;

 	pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);

 	pq_64bit_sub_word(&tmp, 1);

 	offset = pq_64bit_get_word(&tmp);

 	if ( pq_64bit_is_bit_set(&(bitmap->map), offset))

 		{

 		pq_64bit_free(&rcd_num);

 		pq_64bit_free(&tmp);

 		return 0;

 		}

 	}

 #else

 	mask <<= (bitmap->max_seq_num - rcd_num - 1);

 	if (bitmap->map & mask)

 		return 0; /* record previously received */

 #endif

 	pq_64bit_assign(seq_num, &rcd_num);

 	pq_64bit_free(&rcd_num);

 	pq_64bit_free(&tmp);

 	return 1;

 	}

 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)

 	{

 	unsigned int shift;

 	PQ_64BIT rcd_num;

 	PQ_64BIT tmp;

 	PQ_64BIT_CTX *ctx;

 	pq_64bit_init(&rcd_num);

 	pq_64bit_init(&tmp);

 	pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);

 	/* unfortunate code complexity due to 64-bit manipulation support

 	 * on 32-bit machines */

 	if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||

 		pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))

 		{

 		pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));

 		pq_64bit_add_word(&tmp, 1);

 		shift = (unsigned int)pq_64bit_get_word(&tmp);

 		pq_64bit_lshift(&(tmp), &(bitmap->map), shift);

 		pq_64bit_assign(&(bitmap->map), &tmp);

 		pq_64bit_set_bit(&(bitmap->map), 0);

 		pq_64bit_add_word(&rcd_num, 1);

 		pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);

 		pq_64bit_assign_word(&tmp, 1);

 		pq_64bit_lshift(&tmp, &tmp, bitmap->length);

 		ctx = pq_64bit_ctx_new(&ctx);

 		pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);

 		pq_64bit_ctx_free(ctx);

 		}

 	else

 		{

 		pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);

 		pq_64bit_sub_word(&tmp, 1);

 		shift = (unsigned int)pq_64bit_get_word(&tmp);

 		pq_64bit_set_bit(&(bitmap->map), shift);

 		}

 	pq_64bit_free(&rcd_num);

 	pq_64bit_free(&tmp);

 	}

 int dtls1_dispatch_alert(SSL *s)

 	{

 	int i,j;

 	void (*cb)(const SSL *ssl,int type,int val)=NULL;

 	unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */

 	unsigned char *ptr = &buf[0];

 	s->s3->alert_dispatch=0;

 	memset(buf, 0x00, sizeof(buf));

 	*ptr++ = s->s3->send_alert[0];

 	*ptr++ = s->s3->send_alert[1];

 	if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)

 		{	

 		s2n(s->d1->handshake_read_seq, ptr);

 #if 0

 		if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */

 		else

 			s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */

 #endif

 #if 0

 		fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);

 #endif

 		l2n3(s->d1->r_msg_hdr.frag_off, ptr);

 		}

 	i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);

 	if (i <= 0)

 		{

 		s->s3->alert_dispatch=1;

 		/* fprintf( stderr, "not done with alert\n" ); */

 		}

 	else

 		{

 		if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||

 			s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)

 			(void)BIO_flush(s->wbio);

 		if (s->msg_callback)

 			s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 

 				2, s, s->msg_callback_arg);

 		if (s->info_callback != NULL)

 			cb=s->info_callback;

 		else if (s->ctx->info_callback != NULL)

 			cb=s->ctx->info_callback;

 		if (cb != NULL)

 			{

 			j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];

 			cb(s,SSL_CB_WRITE_ALERT,j);

 			}

 		}

 	return(i);

 	}

 static DTLS1_BITMAP *

 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)

     {

     *is_next_epoch = 0;

     /* In current epoch, accept HM, CCS, DATA, & ALERT */

     if (rr->epoch == s->d1->r_epoch)

         return &s->d1->bitmap;

     /* Only HM and ALERT messages can be from the next epoch */

     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&

         (rr->type == SSL3_RT_HANDSHAKE ||

             rr->type == SSL3_RT_ALERT))

         {

         *is_next_epoch = 1;

         return &s->d1->next_bitmap;

         }

     return NULL;

     }

 #if 0

 static int

 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,

 	unsigned long *offset)

 	{

 	/* alerts are passed up immediately */

 	if ( rr->type == SSL3_RT_APPLICATION_DATA ||

 		rr->type == SSL3_RT_ALERT)

 		return 0;

 	/* Only need to buffer if a handshake is underway.

 	 * (this implies that Hello Request and Client Hello are passed up

 	 * immediately) */

 	if ( SSL_in_init(s))

 		{

 		unsigned char *data = rr->data;

 		/* need to extract the HM/CCS sequence number here */

 		if ( rr->type == SSL3_RT_HANDSHAKE ||

 			rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)

 			{

 			unsigned short seq_num;

 			struct hm_header_st msg_hdr;

 			struct ccs_header_st ccs_hdr;

 			if ( rr->type == SSL3_RT_HANDSHAKE)

 				{

 				dtls1_get_message_header(data, &msg_hdr);

 				seq_num = msg_hdr.seq;

 				*offset = msg_hdr.frag_off;

 				}

 			else

 				{

 				dtls1_get_ccs_header(data, &ccs_hdr);

 				seq_num = ccs_hdr.seq;

 				*offset = 0;

 				}

 			/* this is either a record we're waiting for, or a

 			 * retransmit of something we happened to previously 

 			 * receive (higher layers will drop the repeat silently */

 			if ( seq_num < s->d1->handshake_read_seq)

 				return 0;

 			if (rr->type == SSL3_RT_HANDSHAKE && 

 				seq_num == s->d1->handshake_read_seq &&

 				msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)

 				return 0;

 			else if ( seq_num == s->d1->handshake_read_seq &&

 				(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||

 					msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))

 				return 0;

 			else

 				{

 				*priority = seq_num;

 				return 1;

 				}

 			}

 		else /* unknown record type */

 			return 0;

 		}

 	return 0;

 	}

 #endif

 void

 dtls1_reset_seq_numbers(SSL *s, int rw)

 	{

 	unsigned char *seq;

 	unsigned int seq_bytes = sizeof(s->s3->read_sequence);

 	if ( rw & SSL3_CC_READ)

 		{

 		seq = s->s3->read_sequence;

 		s->d1->r_epoch++;

 		pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));

 		s->d1->bitmap.length = s->d1->next_bitmap.length;

 		pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 

 			&(s->d1->next_bitmap.max_seq_num));

 		pq_64bit_free(&(s->d1->next_bitmap.map));

 		pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));

 		memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));

 		pq_64bit_init(&(s->d1->next_bitmap.map));

 		pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));

 		}

 	else

 		{

 		seq = s->s3->write_sequence;

 		s->d1->w_epoch++;

 		}

 	memset(seq, 0x00, seq_bytes);

 	}

 #if PQ_64BIT_IS_INTEGER

 static PQ_64BIT

 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)

        {

        PQ_64BIT _num;

        _num = (((PQ_64BIT)bytes[0]) << 56) |

                (((PQ_64BIT)bytes[1]) << 48) |

                (((PQ_64BIT)bytes[2]) << 40) |

                (((PQ_64BIT)bytes[3]) << 32) |

                (((PQ_64BIT)bytes[4]) << 24) |

                (((PQ_64BIT)bytes[5]) << 16) |

                (((PQ_64BIT)bytes[6]) <<  8) |

                (((PQ_64BIT)bytes[7])      );

 	   *num = _num ;

        return _num;

        }

 #endif

 static void

 dtls1_clear_timeouts(SSL *s)

 	{

 	memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));

 	}