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openssl/ssl/d1_pkt.c.orig

Index: openssl/ssl/d1_pkt.c.orig
===================================================================
--- openssl/ssl/d1_pkt.c.orig	(revision 0)
+++ openssl/ssl/d1_pkt.c.orig	(revision 0)
@@ -0,0 +1,1777 @@
+/* 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>
+
+/* mod 128 saturating subtract of two 64-bit values in big-endian order */
+static int satsub64be(const unsigned char *v1,const unsigned char *v2)
+{	int ret,sat,brw,i;
+
+	if (sizeof(long) == 8) do
+	{	const union { long one; char little; } is_endian = {1};
+		long l;
+
+		if (is_endian.little)			break;
+		/* not reached on little-endians */
+		/* following test is redundant, because input is
+		 * always aligned, but I take no chances... */
+		if (((size_t)v1|(size_t)v2)&0x7)	break;
+
+		l  = *((long *)v1);
+		l -= *((long *)v2);
+		if (l>128)		return 128;
+		else if (l<-128)	return -128;
+		else			return (int)l;
+	} while (0);
+
+	ret = (int)v1[7]-(int)v2[7];
+	sat = 0;
+	brw = ret>>8;	/* brw is either 0 or -1 */
+	if (ret & 0x80)
+	{	for (i=6;i>=0;i--)
+		{	brw += (int)v1[i]-(int)v2[i];
+			sat |= ~brw;
+			brw >>= 8;
+		}
+	}
+	else
+	{	for (i=6;i>=0;i--)
+		{	brw += (int)v1[i]-(int)v2[i];
+			sat |= brw;
+			brw >>= 8;
+		}
+	}
+	brw <<= 8;	/* brw is either 0 or -256 */
+
+	if (sat&0xff)	return brw | 0x80;
+	else		return brw + (ret&0xFF);
+}
+
+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);
+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,
+	unsigned char *priority);
+static int dtls1_process_record(SSL *s);
+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));
+	
+	/* Set proper sequence number for mac calculation */
+	memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
+    
+    return(1);
+    }
+
+
+static int
+dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
+	{
+	DTLS1_RECORD_DATA *rdata;
+	pitem *item;
+
+	/* Limit the size of the queue to prevent DOS attacks */
+	if (pqueue_size(queue->q) >= 100)
+		return 0;
+		
+	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)
+        {
+        /* 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];
+	int decryption_failed_or_bad_record_mac = 0;
+
+
+	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)
+		{
+		/* To minimize information leaked via timing, we will always
+		 * perform all computations before discarding the message.
+		 */
+		decryption_failed_or_bad_record_mac = 1;
+		}
+
+#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)
+		{
+		/* !clear => s->read_hash != NULL => mac_size != -1 */
+		int t;
+		t=EVP_MD_CTX_size(s->read_hash);
+		OPENSSL_assert(t >= 0);
+		mac_size=t;
+
+		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
+			decryption_failed_or_bad_record_mac = 1;
+#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
+			decryption_failed_or_bad_record_mac = 1;
+#endif
+			}
+		rr->length-=mac_size;
+		i=s->method->ssl3_enc->mac(s,md,0);
+		if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+			{
+			decryption_failed_or_bad_record_mac = 1;
+			}
+		}
+
+	if (decryption_failed_or_bad_record_mac)
+		{
+		/* decryption failed, silently discard message */
+		rr->length = 0;
+		s->packet_length = 0;
+		goto err;
+		}
+
+	/* 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);
+
+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;
+	int i,n;
+	SSL3_RECORD *rr;
+	unsigned char *p = NULL;
+	unsigned short version;
+	DTLS1_BITMAP *bitmap;
+	unsigned int is_next_epoch;
+
+	rr= &(s->s3->rrec);
+
+	/* The epoch may have changed.  If so, process all the
+	 * pending records.  This is a non-blocking operation. */
+	dtls1_process_buffered_records(s);
+
+	/* 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 */
+
+		/* this packet contained a partial record, dump it */
+		if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
+			{
+			s->packet_length = 0;
+			goto again;
+			}
+
+		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)
+				{
+				/* unexpected version, silently discard */
+				rr->length = 0;
+				s->packet_length = 0;
+				goto again;
+				}
+			}
+
+		if ((version & 0xff00) != (s->version & 0xff00))
+			{
+			/* wrong version, silently discard record */
+			rr->length = 0;
+			s->packet_length = 0;
+			goto again;
+			}
+
+		if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
+			{
+			/* record too long, silently discard it */
+			rr->length = 0;
+			s->packet_length = 0;
+			goto again;
+			}
+
+		/* 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)
+			{
+			rr->length = 0;
+			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)
+		{
+		rr->length = 0;
+		s->packet_length = 0;  /* dump this record */
+		goto again;   /* get another record */
+		}
+
+	/* Check whether this is a repeat, or aged record.
+	 * Don't check if we're listening and this message is
+	 * a ClientHello. They can look as if they're replayed,
+	 * since they arrive from different connections and
+	 * would be dropped unnecessarily.
+	 */
+	if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
+		*p == SSL3_MT_CLIENT_HELLO) &&
+		!dtls1_record_replay_check(s, bitmap))
+		{
+		rr->length = 0;
+		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),
+	 * and a handshake is currently in progress, buffer it since it
+	 * cannot be processed at this time. However, do not buffer
+	 * anything while listening.
+	 */
+	if (is_next_epoch)
+		{
+		if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
+			{
+			dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+			}
+		rr->length = 0;
+		s->packet_length = 0;
+		goto again;
+		}
+
+	if (!dtls1_process_record(s))
+		{
+		rr->length = 0;
+		s->packet_length = 0;  /* dump this record */
+		goto again;   /* get another record */
+		}
+
+	dtls1_clear_timeouts(s);  /* done waiting */
+	return(1);
+
+	}
+
+/* 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);
+
+	/* We are not handshaking and have no data yet,
+	 * so process data buffered during the last handshake
+	 * in advance, if any.
+	 */
+	if (s->state == SSL_ST_OK && rr->length == 0)
+		{
+		pitem *item;
+		item = pqueue_pop(s->d1->buffered_app_data.q);
+		if (item)
+			{
+			dtls1_copy_record(s, item);
+
+			OPENSSL_free(item->data);
+			pitem_free(item);
+			}
+		}
+
+	/* Check for timeout */
+	if (dtls1_handle_timeout(s) > 0)
+		goto start;
+
+	/* 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))
+		{
+		/* We now have application data between CCS and Finished.
+		 * Most likely the packets were reordered on their way, so
+		 * buffer the application data for later processing rather
+		 * than dropping the connection.
+		 */
+		dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
+		rr->length = 0;
+		goto start;
+		}
+
+	/* 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 application data or wrong */
+		else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
+			{
+			/* Application data while renegotiating
+			 * is allowed. Try again reading.
+			 */
+			if (rr->type == SSL3_RT_APPLICATION_DATA)
+				{
+				BIO *bio;
+				s->s3->in_read_app_data=2;
+				bio=SSL_get_rbio(s);
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(bio);
+				BIO_set_retry_read(bio);
+				return(-1);
+				}
+
+			/* 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)
+				{
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+				/*
+				 * for normal alerts rr->length is 2, while
+				 * dest_maxlen is 7 if we were to handle this
+				 * non-existing alert...
+				 */
+				FIX ME
+#endif
+				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,
+										 dtls1_get_queue_priority(frag->msg_header.seq, 0),
+										 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;
+		unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
+
+		dtls1_get_ccs_header(rr->data, &ccs_hdr);
+
+		if (s->version == DTLS1_BAD_VER)
+			ccs_hdr_len = 3;
+
+		/* '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 (	(rr->length != ccs_hdr_len) || 
+			(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);
+
+		/* We can't process a CCS now, because previous handshake
+		 * messages are still missing, so just drop it.
+		 */
+		if (!s->d1->change_cipher_spec_ok)
+			{
+			goto start;
+			}
+
+		s->d1->change_cipher_spec_ok = 0;
+
+		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->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 we are server, we may have a repeated FINISHED of the
+		 * client here, then retransmit our CCS and FINISHED.
+		 */
+		if (msg_hdr.type == SSL3_MT_FINISHED)
+			{
+			dtls1_retransmit_buffered_messages(s);
+			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)
+	{
+	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;
+			}
+		}
+
+	if (len > SSL3_RT_MAX_PLAIN_LENGTH)
+		{
+			SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
+			return -1;
+		}
+
+	i = dtls1_write_bytes(s, type, buf_, len);
+	return i;
+	}
+
+
+	/* 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)
+	{
+	int i;
+
+	OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
+	s->rwstate=SSL_NOTHING;
+	i=do_dtls1_write(s, type, buf, len, 0);
+	return 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) ||
+		(EVP_MD_CTX_md(s->write_hash) == NULL))
+		clear=1;
+
+	if (clear)
+		mac_size=0;
+	else
+		{
+		mac_size=EVP_MD_CTX_size(s->write_hash);
+		if (mac_size < 0)
+			goto err;
+		}
+
+	/* 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 && SSL_version(s) != DTLS1_BAD_VER)
+		{
+		/* 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;
+
+	*(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)
+		{
+		if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
+			goto err;
+		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)
+	{
+	int cmp;
+	unsigned int shift;
+	const unsigned char *seq = s->s3->read_sequence;
+
+	cmp = satsub64be(seq,bitmap->max_seq_num);
+	if (cmp > 0)
+		{
+		memcpy (s->s3->rrec.seq_num,seq,8);
+		return 1; /* this record in new */
+		}
+	shift = -cmp;
+	if (shift >= sizeof(bitmap->map)*8)
+		return 0; /* stale, outside the window */
+	else if (bitmap->map & (1UL<<shift))
+		return 0; /* record previously received */
+
+	memcpy (s->s3->rrec.seq_num,seq,8);
+	return 1;
+	}
+
+
+static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
+	{
+	int cmp;
+	unsigned int shift;
+	const unsigned char *seq = s->s3->read_sequence;
+
+	cmp = satsub64be(seq,bitmap->max_seq_num);
+	if (cmp > 0)
+		{
+		shift = cmp;
+		if (shift < sizeof(bitmap->map)*8)
+			bitmap->map <<= shift, bitmap->map |= 1UL;
+		else
+			bitmap->map = 1UL;
+		memcpy(bitmap->max_seq_num,seq,8);
+		}
+	else	{
+		shift = -cmp;
+		if (shift < sizeof(bitmap->map)*8)
+			bitmap->map |= 1UL<<shift;
+		}
+	}
+
+
+int dtls1_dispatch_alert(SSL *s)
+	{
+	int i,j;
+	void (*cb)(const SSL *ssl,int type,int val)=NULL;
+	unsigned char buf[DTLS1_AL_HEADER_LENGTH];
+	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];
+
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+	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);
+		}
+#endif
+
+	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
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+		    || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+#endif
+		    )
+			(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++;
+		memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
+		memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
+		}
+	else
+		{
+		seq = s->s3->write_sequence;
+		memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
+		s->d1->w_epoch++;
+		}
+
+	memset(seq, 0x00, seq_bytes);
+	}
+
+
+static void
+dtls1_clear_timeouts(SSL *s)
+	{
+	memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
+	}