PR: 1997
[openssl.git] / ssl / d1_both.c
index 92661a9e3b0d531ad27700b72a64d58b1eade3c8..5bb0a4ff6ce1f02e2b54c0f4b638dee97ff5602a 100644 (file)
@@ -136,40 +136,41 @@ static unsigned char *dtls1_write_message_header(SSL *s,
 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
        unsigned long len, unsigned short seq_num, unsigned long frag_off, 
        unsigned long frag_len);
-static int dtls1_retransmit_buffered_messages(SSL *s);
 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 
-    long max, int *ok);
-static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
+       long max, int *ok);
 
 static hm_fragment *
 dtls1_hm_fragment_new(unsigned long frag_len)
-    {
-    hm_fragment *frag = NULL;
-    unsigned char *buf = NULL;
-
-    frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
-    if ( frag == NULL)
-        return NULL;
-
-    buf = (unsigned char *)OPENSSL_malloc(frag_len 
-        + DTLS1_HM_HEADER_LENGTH);
-    if ( buf == NULL)
-        {
-        OPENSSL_free(frag);
-        return NULL;
-        }
-    
-    frag->fragment = buf;
-
-    return frag;
-    }
+       {
+       hm_fragment *frag = NULL;
+       unsigned char *buf = NULL;
+
+       frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
+       if ( frag == NULL)
+               return NULL;
+
+       if (frag_len)
+               {
+               buf = (unsigned char *)OPENSSL_malloc(frag_len);
+               if ( buf == NULL)
+                       {
+                       OPENSSL_free(frag);
+                       return NULL;
+                       }
+               }
+
+       /* zero length fragment gets zero frag->fragment */
+       frag->fragment = buf;
+
+       return frag;
+       }
 
 static void
 dtls1_hm_fragment_free(hm_fragment *frag)
-    {
-    OPENSSL_free(frag->fragment);
-    OPENSSL_free(frag);
-    }
+       {
+       if (frag->fragment) OPENSSL_free(frag->fragment);
+       OPENSSL_free(frag);
+       }
 
 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 int dtls1_do_write(SSL *s, int type)
@@ -180,7 +181,7 @@ int dtls1_do_write(SSL *s, int type)
 
        /* AHA!  Figure out the MTU, and stick to the right size */
        if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
-        {
+               {
                s->d1->mtu = 
                        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 
@@ -207,7 +208,7 @@ int dtls1_do_write(SSL *s, int type)
                mtu = curr_mtu;
        else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
                return ret;
-               
+
        if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
                {
                ret = BIO_flush(SSL_get_wbio(s));
@@ -254,11 +255,11 @@ int dtls1_do_write(SSL *s, int type)
                                s->init_off -= DTLS1_HM_HEADER_LENGTH;
                                s->init_num += DTLS1_HM_HEADER_LENGTH;
 
-                /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
+                               /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
                                if ( len <= DTLS1_HM_HEADER_LENGTH)  
                                        len += DTLS1_HM_HEADER_LENGTH;
                                }
-                       
+
                        dtls1_fix_message_header(s, frag_off, 
                                len - DTLS1_HM_HEADER_LENGTH);
 
@@ -286,18 +287,40 @@ int dtls1_do_write(SSL *s, int type)
                        }
                else
                        {
-                       
+
                        /* bad if this assert fails, only part of the handshake
                         * message got sent.  but why would this happen? */
-                       OPENSSL_assert(len == (unsigned int)ret); 
-                       
+                       OPENSSL_assert(len == (unsigned int)ret);
+
                        if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
+                               {
                                /* should not be done for 'Hello Request's, but in that case
                                 * we'll ignore the result anyway */
-                               ssl3_finish_mac(s, 
-                                       (unsigned char *)&s->init_buf->data[s->init_off + 
-                                               DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
-                       
+                               unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
+                               const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+                               int xlen;
+
+                               if (frag_off == 0 && s->version != DTLS1_BAD_VER)
+                                       {
+                                       /* reconstruct message header is if it
+                                        * is being sent in single fragment */
+                                       *p++ = msg_hdr->type;
+                                       l2n3(msg_hdr->msg_len,p);
+                                       s2n (msg_hdr->seq,p);
+                                       l2n3(0,p);
+                                       l2n3(msg_hdr->msg_len,p);
+                                       p  -= DTLS1_HM_HEADER_LENGTH;
+                                       xlen = ret;
+                                       }
+                               else
+                                       {
+                                       p  += DTLS1_HM_HEADER_LENGTH;
+                                       xlen = ret - DTLS1_HM_HEADER_LENGTH;
+                                       }
+
+                               ssl3_finish_mac(s, p, xlen);
+                               }
+
                        if (ret == s->init_num)
                                {
                                if (s->msg_callback)
@@ -307,7 +330,7 @@ int dtls1_do_write(SSL *s, int type)
 
                                s->init_off = 0;  /* done writing this message */
                                s->init_num = 0;
-                               
+
                                return(1);
                                }
                        s->init_off+=ret;
@@ -327,6 +350,7 @@ int dtls1_do_write(SSL *s, int type)
 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
        {
        int i, al;
+       struct hm_header_st *msg_hdr;
 
        /* s3->tmp is used to store messages that are unexpected, caused
         * by the absence of an optional handshake message */
@@ -344,25 +368,57 @@ long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
                s->init_num = (int)s->s3->tmp.message_size;
                return s->init_num;
                }
-       
+
+       msg_hdr = &s->d1->r_msg_hdr;
        do
                {
-               if ( s->d1->r_msg_hdr.frag_off == 0)
+               if ( msg_hdr->frag_off == 0)
                        {
                        /* s->d1->r_message_header.msg_len = 0; */
-                       memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
+                       memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
                        }
 
                i = dtls1_get_message_fragment(s, st1, stn, max, ok);
                if ( i == DTLS1_HM_BAD_FRAGMENT ||
-            i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
+                       i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
                        continue;
                else if ( i <= 0 && !*ok)
                        return i;
 
-               if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
+               /* Note that s->init_sum is used as a counter summing
+                * up fragments' lengths: as soon as they sum up to
+                * handshake packet length, we assume we have got all
+                * the fragments. Overlapping fragments would cause
+                * premature termination, so we don't expect overlaps.
+                * Well, handling overlaps would require something more
+                * drastic. Indeed, as it is now there is no way to
+                * tell if out-of-order fragment from the middle was
+                * the last. '>=' is the best/least we can do to control
+                * the potential damage caused by malformed overlaps. */
+               if ((unsigned int)s->init_num >= msg_hdr->msg_len)
                        {
-                       memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
+                       unsigned char *p = (unsigned char *)s->init_buf->data;
+                       unsigned long msg_len = msg_hdr->msg_len;
+
+                       /* reconstruct message header as if it was
+                        * sent in single fragment */
+                       *(p++) = msg_hdr->type;
+                       l2n3(msg_len,p);
+                       s2n (msg_hdr->seq,p);
+                       l2n3(0,p);
+                       l2n3(msg_len,p);
+                       if (s->version != DTLS1_BAD_VER) {
+                               p       -= DTLS1_HM_HEADER_LENGTH;
+                               msg_len += DTLS1_HM_HEADER_LENGTH;
+                       }
+
+                       ssl3_finish_mac(s, p, msg_len);
+                       if (s->msg_callback)
+                               s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+                                       p, msg_len,
+                                       s, s->msg_callback_arg);
+
+                       memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
 
                        s->d1->handshake_read_seq++;
                        /* we just read a handshake message from the other side:
@@ -379,11 +435,11 @@ long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
                         * first data  segment, but is there a better way?  */
                        dtls1_clear_record_buffer(s);
 
-            s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
-                       return s->init_num - DTLS1_HM_HEADER_LENGTH;
+                       s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+                       return s->init_num;
                        }
                else
-                       s->d1->r_msg_hdr.frag_off = i;
+                       msg_hdr->frag_off = i;
                } while(1) ;
 
 f_err:
@@ -393,161 +449,198 @@ f_err:
        }
 
 
-static int
-dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
-    {
-    /* (0) check whether the desired fragment is available
-     * if so:
-     * (1) copy over the fragment to s->init_buf->data[]
-     * (2) update s->init_num
-     */
-    pitem *item;
-    hm_fragment *frag;
-    unsigned long overlap;
-    unsigned char *p;
-
-    item = pqueue_peek(s->d1->buffered_messages);
-    if ( item == NULL)
-        return 0;
-
-    frag = (hm_fragment *)item->data;
-    
-    if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
-        frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
-        {
-        pqueue_pop(s->d1->buffered_messages);
-        overlap = s->init_num - DTLS1_HM_HEADER_LENGTH 
-            - frag->msg_header.frag_off;
-
-        p = frag->fragment;
-
-        memcpy(&s->init_buf->data[s->init_num],
-            p + DTLS1_HM_HEADER_LENGTH + overlap,
-            frag->msg_header.frag_len - overlap);
-    
-        OPENSSL_free(frag->fragment);
-        OPENSSL_free(frag);
-        pitem_free(item);
-
-        *copied = frag->msg_header.frag_len - overlap;
-        return *copied;
-        }
-    else
-        return 0;
-    }
+static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
+       {
+       size_t frag_off,frag_len,msg_len;
 
+       msg_len  = msg_hdr->msg_len;
+       frag_off = msg_hdr->frag_off;
+       frag_len = msg_hdr->frag_len;
 
-static int
-dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
-{
-    hm_fragment *frag = NULL;
-    pitem *item = NULL;
-       PQ_64BIT seq64;
+       /* sanity checking */
+       if ( (frag_off+frag_len) > msg_len)
+               {
+               SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
+               return SSL_AD_ILLEGAL_PARAMETER;
+               }
 
-    frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
-    if ( frag == NULL)
-        goto err;
+       if ( (frag_off+frag_len) > (unsigned long)max)
+               {
+               SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
+               return SSL_AD_ILLEGAL_PARAMETER;
+               }
 
-    memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
-        msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
+       if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
+               {
+               /* msg_len is limited to 2^24, but is effectively checked
+                * against max above */
+               if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
+                       {
+                       SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
+                       return SSL_AD_INTERNAL_ERROR;
+                       }
 
-    memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
+               s->s3->tmp.message_size  = msg_len;
+               s->d1->r_msg_hdr.msg_len = msg_len;
+               s->s3->tmp.message_type  = msg_hdr->type;
+               s->d1->r_msg_hdr.type    = msg_hdr->type;
+               s->d1->r_msg_hdr.seq     = msg_hdr->seq;
+               }
+       else if (msg_len != s->d1->r_msg_hdr.msg_len)
+               {
+               /* They must be playing with us! BTW, failure to enforce
+                * upper limit would open possibility for buffer overrun. */
+               SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
+               return SSL_AD_ILLEGAL_PARAMETER;
+               }
 
-    pq_64bit_init(&seq64);
-    pq_64bit_assign_word(&seq64, msg_hdr->seq);
+       return 0; /* no error */
+       }
 
-    item = pitem_new(seq64, frag);
-    if ( item == NULL)
-        goto err;
 
-    pq_64bit_free(&seq64);
+static int
+dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
+       {
+       /* (0) check whether the desired fragment is available
+        * if so:
+        * (1) copy over the fragment to s->init_buf->data[]
+        * (2) update s->init_num
+        */
+       pitem *item;
+       hm_fragment *frag;
+       int al;
 
-    pqueue_insert(s->d1->buffered_messages, item);
-    return 1;
+       *ok = 0;
+       item = pqueue_peek(s->d1->buffered_messages);
+       if ( item == NULL)
+               return 0;
 
-err:
-    if ( frag != NULL) dtls1_hm_fragment_free(frag);
-    if ( item != NULL) OPENSSL_free(item);
-    return 0;
-}
+       frag = (hm_fragment *)item->data;
 
+       if ( s->d1->handshake_read_seq == frag->msg_header.seq)
+               {
+               unsigned long frag_len = frag->msg_header.frag_len;
+               pqueue_pop(s->d1->buffered_messages);
 
-static void
-dtls1_process_handshake_fragment(SSL *s, int frag_len)
-    {
-    unsigned char *p;
+               al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
 
-    p = (unsigned char *)s->init_buf->data;
+               if (al==0) /* no alert */
+                       {
+                       unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
+                       memcpy(&p[frag->msg_header.frag_off],
+                               frag->fragment,frag->msg_header.frag_len);
+                       }
 
-       ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
-    }
+               dtls1_hm_fragment_free(frag);
+               pitem_free(item);
+
+               if (al==0)
+                       {
+                       *ok = 1;
+                       return frag_len;
+                       }
+
+               ssl3_send_alert(s,SSL3_AL_FATAL,al);
+               s->init_num = 0;
+               *ok = 0;
+               return -1;
+               }
+       else
+               return 0;
+       }
 
 
 static int
-dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
-    {
-    int i;
-    unsigned char *p;
-
-    /* make sure there's enough room to read this fragment */
-    if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf, 
-             (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
-        {
-        SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
-        goto err;
-        }
-
-    p = (unsigned char *)s->init_buf->data;
-
-    /* read the body of the fragment (header has already been read */
-    if ( msg_hdr->frag_len > 0)
+dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
+{
+       int i=-1;
+       hm_fragment *frag = NULL;
+       pitem *item = NULL;
+       unsigned char seq64be[8];
+       unsigned long frag_len = msg_hdr->frag_len;
+
+       if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
+               goto err;
+
+       /* Try to find item in queue, to prevent duplicate entries */
+       memset(seq64be,0,sizeof(seq64be));
+       seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
+       seq64be[7] = (unsigned char) msg_hdr->seq;
+       item = pqueue_find(s->d1->buffered_messages, seq64be);
+       
+       /* Discard the message if sequence number was already there, is
+        * too far in the future, already in the queue or if we received
+        * a FINISHED before the SERVER_HELLO, which then must be a stale
+        * retransmit.
+        */
+       if (msg_hdr->seq <= s->d1->handshake_read_seq ||
+               msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
+               (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
                {
-               i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
-            &p[s->init_num], 
-            msg_hdr->frag_len,0);
-               if (i <= 0)
+               unsigned char devnull [256];
+
+               while (frag_len)
                        {
-                       *ok = 0;
-                       return i;
+                       i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
+                               devnull,
+                               frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
+                       if (i<=0) goto err;
+                       frag_len -= i;
                        }
                }
 
-    if ( msg_hdr->seq > s->d1->handshake_read_seq)
-        dtls1_buffer_handshake_fragment(s, msg_hdr);
-    else
-        OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
+       if (frag_len)
+               {
+               frag = dtls1_hm_fragment_new(frag_len);
+               if ( frag == NULL)
+                       goto err;
+
+               memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
+
+               /* read the body of the fragment (header has already been read */
+               i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
+                       frag->fragment,frag_len,0);
+               if (i<=0 || (unsigned long)i!=frag_len)
+                       goto err;
+
+               memset(seq64be,0,sizeof(seq64be));
+               seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
+               seq64be[7] = (unsigned char)(msg_hdr->seq);
+
+               item = pitem_new(seq64be, frag);
+               if ( item == NULL)
+                       goto err;
+
+               pqueue_insert(s->d1->buffered_messages, item);
+               }
+
+       return DTLS1_HM_FRAGMENT_RETRY;
 
-    return DTLS1_HM_FRAGMENT_RETRY;
 err:
-    *ok = 0;
-    return -1;
-    }
+       if ( frag != NULL) dtls1_hm_fragment_free(frag);
+       if ( item != NULL) OPENSSL_free(item);
+       *ok = 0;
+       return i;
+       }
 
 
 static long
 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
        {
-       unsigned char *p;
+       unsigned char wire[DTLS1_HM_HEADER_LENGTH];
        unsigned long l, frag_off, frag_len;
        int i,al;
        struct hm_header_st msg_hdr;
-    unsigned long overlap;
-    
-    /* see if we have the required fragment already */
-    if (dtls1_retrieve_buffered_fragment(s, &l))
-    {
-        /* compute MAC, remove fragment headers */
-        dtls1_process_handshake_fragment(s, l);
-        s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
-        s->state = stn;
-        return 1;
-    }
-
-    /* get a handshake fragment from the record layer */
-       p = (unsigned char *)s->init_buf->data;
-
-    /* read handshake message header */
-       i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
+
+       /* see if we have the required fragment already */
+       if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
+               {
+               if (*ok)        s->init_num += frag_len;
+               return frag_len;
+               }
+
+       /* read handshake message header */
+       i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
                DTLS1_HM_HEADER_LENGTH, 0);
        if (i <= 0)     /* nbio, or an error */
                {
@@ -555,130 +648,61 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
                *ok = 0;
                return i;
                }
-
        OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 
-       p += s->init_num;
-    /* parse the message fragment header */
-    
-    dtls1_get_message_header(p, &msg_hdr);
+       /* parse the message fragment header */
+       dtls1_get_message_header(wire, &msg_hdr);
 
-    /* 
-     * if this is a future (or stale) message it gets buffered
-     * (or dropped)--no further processing at this time 
-     */
-    if ( msg_hdr.seq != s->d1->handshake_read_seq)
-        return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
+       /* 
+        * if this is a future (or stale) message it gets buffered
+        * (or dropped)--no further processing at this time 
+        */
+       if ( msg_hdr.seq != s->d1->handshake_read_seq)
+               return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 
-    l = msg_hdr.msg_len;
-    frag_off = msg_hdr.frag_off;
+       l = msg_hdr.msg_len;
+       frag_off = msg_hdr.frag_off;
        frag_len = msg_hdr.frag_len;
 
-    /* sanity checking */
-    if ( frag_off + frag_len > l)
-        {
-        al=SSL_AD_ILLEGAL_PARAMETER;
-        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
-        goto f_err;
-        }
-
        if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
-        p[0] == SSL3_MT_HELLO_REQUEST)
-        {
-        /* The server may always send 'Hello Request' messages --
-         * we are doing a handshake anyway now, so ignore them
-         * if their format is correct. Does not count for
-         * 'Finished' MAC. */
-        if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
-            {
-            if (s->msg_callback)
-                s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
-                    p, DTLS1_HM_HEADER_LENGTH, s, 
-                    s->msg_callback_arg);
-            
-            s->init_num = 0;
-            return dtls1_get_message_fragment(s, st1, stn,
-                max, ok);
-            }
-        else /* Incorrectly formated Hello request */
-            {
-            al=SSL_AD_UNEXPECTED_MESSAGE;
-            SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
-            goto f_err;
-            }
-        }
-
-    /* XDTLS: do a sanity check on the fragment */
-
-    s->init_num += i;
-
-       if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
+               wire[0] == SSL3_MT_HELLO_REQUEST)
                {
-               /* BUF_MEM_grow takes an 'int' parameter */
-               if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH)) 
-                       {
-                       al=SSL_AD_ILLEGAL_PARAMETER;
-                       SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
-                       goto f_err;
-                       }
-               if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
-                       + DTLS1_HM_HEADER_LENGTH))
+               /* The server may always send 'Hello Request' messages --
+                * we are doing a handshake anyway now, so ignore them
+                * if their format is correct. Does not count for
+                * 'Finished' MAC. */
+               if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
                        {
-                       SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
-                       goto err;
+                       if (s->msg_callback)
+                               s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
+                                       wire, DTLS1_HM_HEADER_LENGTH, s, 
+                                       s->msg_callback_arg);
+                       
+                       s->init_num = 0;
+                       return dtls1_get_message_fragment(s, st1, stn,
+                               max, ok);
                        }
-        /* Only do this test when we're reading the expected message.
-         * Stale messages will be dropped and future messages will be buffered */
-        if ( l > (unsigned long)max)
+               else /* Incorrectly formated Hello request */
                        {
-                       al=SSL_AD_ILLEGAL_PARAMETER;
-                       SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
+                       al=SSL_AD_UNEXPECTED_MESSAGE;
+                       SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
                        goto f_err;
                        }
-
-               s->s3->tmp.message_size=l;
                }
 
-    if ( frag_len > (unsigned long)max)
-        {
-        al=SSL_AD_ILLEGAL_PARAMETER;
-        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
-        goto f_err;
-        }
-    if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
-        {
-        al=SSL_AD_ILLEGAL_PARAMETER;
-        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
-        goto f_err;
-        }
-
-    if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len 
-             + DTLS1_HM_HEADER_LENGTH + s->init_num))
-        {
-        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
-        goto err;
-        }
-
-       if ( s->d1->r_msg_hdr.frag_off == 0)
-               {
-               s->s3->tmp.message_type = msg_hdr.type;
-               s->d1->r_msg_hdr.type = msg_hdr.type;
-               s->d1->r_msg_hdr.msg_len = l;
-               /* s->d1->r_msg_hdr.seq = seq_num; */
-               }
+       if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
+               goto f_err;
 
        /* XDTLS:  ressurect this when restart is in place */
        s->state=stn;
-       
-       /* next state (stn) */
-       p = (unsigned char *)s->init_buf->data;
 
        if ( frag_len > 0)
                {
+               unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
+
                i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
-            &p[s->init_num], 
-            frag_len,0);
-        /* XDTLS:  fix this--message fragments cannot span multiple packets */
+                       &p[frag_off],frag_len,0);
+               /* XDTLS:  fix this--message fragments cannot span multiple packets */
                if (i <= 0)
                        {
                        s->rwstate=SSL_READING;
@@ -689,70 +713,23 @@ dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
        else
                i = 0;
 
-    /* XDTLS:  an incorrectly formatted fragment should cause the 
-     * handshake to fail */
+       /* XDTLS:  an incorrectly formatted fragment should cause the 
+        * handshake to fail */
        OPENSSL_assert(i == (int)frag_len);
 
-#if 0
-    /* Successfully read a fragment.
-     * It may be (1) out of order, or
-     *           (2) it's a repeat, in which case we dump it
-     *           (3) the one we are expecting next (maybe with overlap)
-     * If it is next one, it may overlap with previously read bytes
-     */
-
-    /* case (1): buffer the future fragment 
-     * (we can treat fragments from a future message the same
-     * as future fragments from the message being currently read, since
-     * they are sematically simply out of order.
-     */
-    if ( msg_hdr.seq > s->d1->handshake_read_seq ||
-        frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
-    {
-        dtls1_buffer_handshake_fragment(s, &msg_hdr);
-        return DTLS1_HM_FRAGMENT_RETRY;
-    }
-
-    /* case (2):  drop the entire fragment, and try again */
-    if ( msg_hdr.seq < s->d1->handshake_read_seq ||
-        frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
-        {
-        s->init_num -= DTLS1_HM_HEADER_LENGTH;
-        return DTLS1_HM_FRAGMENT_RETRY;
-        }
-#endif
+       *ok = 1;
 
-    /* case (3): received a immediately useful fragment.  Determine the 
-     * possible overlap and copy the fragment.
-     */
-    overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
-        
-    /* retain the header for the first fragment */
-    if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
-        {
-        memmove(&(s->init_buf->data[s->init_num]),
-            &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
-            frag_len - overlap);
-
-        s->init_num += frag_len - overlap;
-        }
-    else
-        s->init_num += frag_len;
-
-    dtls1_process_handshake_fragment(s, frag_len - overlap);
-
-       if (s->msg_callback)
-               s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, 
-                       (size_t)s->init_num, s, 
-                       s->msg_callback_arg);
-       *ok=1;
-
-       return s->init_num;
+       /* Note that s->init_num is *not* used as current offset in
+        * s->init_buf->data, but as a counter summing up fragments'
+        * lengths: as soon as they sum up to handshake packet
+        * length, we assume we have got all the fragments. */
+       s->init_num += frag_len;
+       return frag_len;
 
 f_err:
        ssl3_send_alert(s,SSL3_AL_FATAL,al);
-    s->init_num = 0;
-err:
+       s->init_num = 0;
+
        *ok=0;
        return(-1);
        }
@@ -769,8 +746,6 @@ int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
                p= &(d[DTLS1_HM_HEADER_LENGTH]);
 
                i=s->method->ssl3_enc->final_finish_mac(s,
-                       &(s->s3->finish_dgst1),
-                       &(s->s3->finish_dgst2),
                        sender,slen,s->s3->tmp.finish_md);
                s->s3->tmp.finish_md_len = i;
                memcpy(p, s->s3->tmp.finish_md, i);
@@ -790,7 +765,7 @@ int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 
                /* buffer the message to handle re-xmits */
                dtls1_buffer_message(s, 0);
-               
+
                s->state=b;
                }
 
@@ -815,10 +790,14 @@ int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
                p=(unsigned char *)s->init_buf->data;
                *p++=SSL3_MT_CCS;
                s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
-               s->d1->next_handshake_write_seq++;
-               s2n(s->d1->handshake_write_seq,p);
-
                s->init_num=DTLS1_CCS_HEADER_LENGTH;
+
+               if (s->version == DTLS1_BAD_VER) {
+                       s->d1->next_handshake_write_seq++;
+                       s2n(s->d1->handshake_write_seq,p);
+                       s->init_num+=2;
+               }
+
                s->init_off=0;
 
                dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 
@@ -834,14 +813,30 @@ int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
        return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
        }
 
+static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
+       {
+       int n;
+       unsigned char *p;
+
+       n=i2d_X509(x,NULL);
+       if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
+               {
+               SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
+               return 0;
+               }
+       p=(unsigned char *)&(buf->data[*l]);
+       l2n3(n,p);
+       i2d_X509(x,&p);
+       *l+=n+3;
+
+       return 1;
+       }
 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
        {
        unsigned char *p;
-       int n,i;
+       int i;
        unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
        BUF_MEM *buf;
-       X509_STORE_CTX xs_ctx;
-       X509_OBJECT obj;
 
        /* TLSv1 sends a chain with nothing in it, instead of an alert */
        buf=s->init_buf;
@@ -852,54 +847,33 @@ unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
                }
        if (x != NULL)
                {
-               if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
-                       {
-                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
-                       return(0);
-                       }
-
-               for (;;)
-                       {
-                       n=i2d_X509(x,NULL);
-                       if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
-                               {
-                               SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
-                               return(0);
-                               }
-                       p=(unsigned char *)&(buf->data[l]);
-                       l2n3(n,p);
-                       i2d_X509(x,&p);
-                       l+=n+3;
-                       if (X509_NAME_cmp(X509_get_subject_name(x),
-                               X509_get_issuer_name(x)) == 0) break;
-
-                       i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
-                               X509_get_issuer_name(x),&obj);
-                       if (i <= 0) break;
-                       x=obj.data.x509;
-                       /* Count is one too high since the X509_STORE_get uped the
-                        * ref count */
-                       X509_free(x);
-                       }
-
-               X509_STORE_CTX_cleanup(&xs_ctx);
-               }
-
-       /* Thawte special :-) */
-       if (s->ctx->extra_certs != NULL)
+               X509_STORE_CTX xs_ctx;
+
+               if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
+                       {
+                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
+                       return(0);
+                       }
+  
+               X509_verify_cert(&xs_ctx);
+               for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
+                       {
+                       x = sk_X509_value(xs_ctx.chain, i);
+
+                       if (!dtls1_add_cert_to_buf(buf, &l, x))
+                               {
+                               X509_STORE_CTX_cleanup(&xs_ctx);
+                               return 0;
+                               }
+                       }
+               X509_STORE_CTX_cleanup(&xs_ctx);
+               }
+       /* Thawte special :-) */
        for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
                {
                x=sk_X509_value(s->ctx->extra_certs,i);
-               n=i2d_X509(x,NULL);
-               if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
-                       {
-                       SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
-                       return(0);
-                       }
-               p=(unsigned char *)&(buf->data[l]);
-               l2n3(n,p);
-               i2d_X509(x,&p);
-               l+=n+3;
+               if (!dtls1_add_cert_to_buf(buf, &l, x))
+                       return 0;
                }
 
        l-= (3 + DTLS1_HM_HEADER_LENGTH);
@@ -915,321 +889,322 @@ unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
        }
 
 int dtls1_read_failed(SSL *s, int code)
-    {
-    DTLS1_STATE *state;
-    BIO *bio;
-    int send_alert = 0;
-
-    if ( code > 0)
-        {
-        fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
-        return 1;
-        }
-
-    bio = SSL_get_rbio(s);
-    if ( ! BIO_dgram_recv_timedout(bio))
-        {
-        /* not a timeout, none of our business, 
-           let higher layers handle this.  in fact it's probably an error */
-        return code;
-        }
-
-    if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
-        {
-        BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
-        return code;
-        }
-
-    state = s->d1;
-    state->timeout.num_alerts++;
-    if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
-        {
-        /* fail the connection, enough alerts have been sent */
-        SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
-        return 0;
-        }
-       
-    state->timeout.read_timeouts++;
-    if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
-        {
-        send_alert = 1;
-        state->timeout.read_timeouts = 1;
-        }
+       {
+       if ( code > 0)
+               {
+               fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
+               return 1;
+               }
+
+       if (!dtls1_is_timer_expired(s))
+               {
+               /* not a timeout, none of our business, 
+                  let higher layers handle this.  in fact it's probably an error */
+               return code;
+               }
+
+       if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
+               {
+               BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
+               return code;
+               }
 
-       
 #if 0 /* for now, each alert contains only one record number */
-    item = pqueue_peek(state->rcvd_records);
-    if ( item )
-        {
-        /* send an alert immediately for all the missing records */
-        }
-    else
+       item = pqueue_peek(state->rcvd_records);
+       if ( item )
+               {
+               /* send an alert immediately for all the missing records */
+               }
+       else
 #endif
 
 #if 0  /* no more alert sending, just retransmit the last set of messages */
-        if ( send_alert)
-            ssl3_send_alert(s,SSL3_AL_WARNING,
-                DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
+       if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
+               ssl3_send_alert(s,SSL3_AL_WARNING,
+                       DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 #endif
 
-    return dtls1_retransmit_buffered_messages(s) ;
-    }
+       return dtls1_handle_timeout(s);
+       }
 
+int
+dtls1_get_queue_priority(unsigned short seq, int is_ccs)
+       {
+       /* The index of the retransmission queue actually is the message sequence number,
+        * since the queue only contains messages of a single handshake. However, the
+        * ChangeCipherSpec has no message sequence number and so using only the sequence
+        * will result in the CCS and Finished having the same index. To prevent this,
+        * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
+        * This does not only differ CSS and Finished, it also maintains the order of the
+        * index (important for priority queues) and fits in the unsigned short variable.
+        */     
+       return seq * 2 - is_ccs;
+       }
 
-static int
+int
 dtls1_retransmit_buffered_messages(SSL *s)
-    {
-    pqueue sent = s->d1->sent_messages;
-    piterator iter;
-    pitem *item;
-    hm_fragment *frag;
-    int found = 0;
-
-    iter = pqueue_iterator(sent);
-
-    for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
-        {
-        frag = (hm_fragment *)item->data;
-        if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
-            found)
-            {
-            fprintf(stderr, "dtls1_retransmit_message() failed\n");
-            return -1;
-            }
-        }
-
-    return 1;
-    }
+       {
+       pqueue sent = s->d1->sent_messages;
+       piterator iter;
+       pitem *item;
+       hm_fragment *frag;
+       int found = 0;
 
-#if 0
-static dtls1_message_buffer *
-dtls1_message_buffer_new(unsigned int len)
-    {
-    dtls1_message_buffer *msg_buf;
-
-    msg_buf = (dtls1_message_buffer *) 
-        OPENSSL_malloc(sizeof(dtls1_message_buffer)); 
-    if ( msg_buf == NULL)
-        return NULL;
-
-    memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
-
-    msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
-    if ( msg_buf->data == NULL)
-        {
-        OPENSSL_free(msg_buf);
-        return NULL;
-        }
-
-    memset(msg_buf->data, 0x00, len);
-    return msg_buf;
-    }
-#endif
+       iter = pqueue_iterator(sent);
 
-#if 0
-static void
-dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
-    {
-    if (msg_buf != NULL)
-        {
-        OPENSSL_free(msg_buf->data);
-        OPENSSL_free(msg_buf);
-        }
-    }
-#endif
+       for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
+               {
+               frag = (hm_fragment *)item->data;
+                       if ( dtls1_retransmit_message(s,
+                               (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
+                               0, &found) <= 0 && found)
+                       {
+                       fprintf(stderr, "dtls1_retransmit_message() failed\n");
+                       return -1;
+                       }
+               }
+
+       return 1;
+       }
 
 int
 dtls1_buffer_message(SSL *s, int is_ccs)
-    {
-    pitem *item;
-    hm_fragment *frag;
-       PQ_64BIT seq64;
-
-    /* this function is called immediately after a message has 
-     * been serialized */
-    OPENSSL_assert(s->init_off == 0);
-
-    frag = dtls1_hm_fragment_new(s->init_num);
-
-    memcpy(frag->fragment, s->init_buf->data, s->init_num);
-
-    if ( is_ccs)
-        {
-        OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
-            DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
-        }
-    else
-        {
-        OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
-            DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
-        }
-
-    frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
-    frag->msg_header.seq = s->d1->w_msg_hdr.seq;
-    frag->msg_header.type = s->d1->w_msg_hdr.type;
-    frag->msg_header.frag_off = 0;
-    frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
-    frag->msg_header.is_ccs = is_ccs;
-
-    pq_64bit_init(&seq64);
-    pq_64bit_assign_word(&seq64, frag->msg_header.seq);
-
-    item = pitem_new(seq64, frag);
-    pq_64bit_free(&seq64);
-    if ( item == NULL)
-        {
-        dtls1_hm_fragment_free(frag);
-        return 0;
-        }
+       {
+       pitem *item;
+       hm_fragment *frag;
+       unsigned char seq64be[8];
+
+       /* this function is called immediately after a message has 
+        * been serialized */
+       OPENSSL_assert(s->init_off == 0);
+
+       frag = dtls1_hm_fragment_new(s->init_num);
+
+       memcpy(frag->fragment, s->init_buf->data, s->init_num);
+
+       if ( is_ccs)
+               {
+               OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
+                              ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
+               }
+       else
+               {
+               OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
+                       DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
+               }
+
+       frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
+       frag->msg_header.seq = s->d1->w_msg_hdr.seq;
+       frag->msg_header.type = s->d1->w_msg_hdr.type;
+       frag->msg_header.frag_off = 0;
+       frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
+       frag->msg_header.is_ccs = is_ccs;
+
+       /* save current state*/
+       frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
+       frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
+       frag->msg_header.saved_retransmit_state.compress = s->compress;
+       frag->msg_header.saved_retransmit_state.session = s->session;
+       frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
+       
+       memset(seq64be,0,sizeof(seq64be));
+       seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
+                                                                                                                 frag->msg_header.is_ccs)>>8);
+       seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
+                                                                                                                 frag->msg_header.is_ccs));
+
+       item = pitem_new(seq64be, frag);
+       if ( item == NULL)
+               {
+               dtls1_hm_fragment_free(frag);
+               return 0;
+               }
 
 #if 0
-    fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
-    fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
-    fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
+       fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
+       fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
+       fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
 #endif
 
-    pqueue_insert(s->d1->sent_messages, item);
-    return 1;
-    }
+       pqueue_insert(s->d1->sent_messages, item);
+       return 1;
+       }
 
 int
 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
-    int *found)
-    {
-    int ret;
-    /* XDTLS: for now assuming that read/writes are blocking */
-    pitem *item;
-    hm_fragment *frag ;
-    unsigned long header_length;
-       PQ_64BIT seq64;
-
-    /*
-      OPENSSL_assert(s->init_num == 0);
-      OPENSSL_assert(s->init_off == 0);
-     */
-
-    /* XDTLS:  the requested message ought to be found, otherwise error */
-    pq_64bit_init(&seq64);
-    pq_64bit_assign_word(&seq64, seq);
-
-    item = pqueue_find(s->d1->sent_messages, seq64);
-    pq_64bit_free(&seq64);
-    if ( item == NULL)
-        {
-        fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
-        *found = 0;
-        return 0;
-        }
-
-    *found = 1;
-    frag = (hm_fragment *)item->data;
-
-    if ( frag->msg_header.is_ccs)
-        header_length = DTLS1_CCS_HEADER_LENGTH;
-    else
-        header_length = DTLS1_HM_HEADER_LENGTH;
-
-    memcpy(s->init_buf->data, frag->fragment, 
-        frag->msg_header.msg_len + header_length);
-        s->init_num = frag->msg_header.msg_len + header_length;
-    
-    dtls1_set_message_header_int(s, frag->msg_header.type, 
-        frag->msg_header.msg_len, frag->msg_header.seq, 0, 
-        frag->msg_header.frag_len);
-
-    s->d1->retransmitting = 1;
-    ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 
-        SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
-    s->d1->retransmitting = 0;
-
-    BIO_flush(SSL_get_wbio(s));
-    return ret;
-    }
+       int *found)
+       {
+       int ret;
+       /* XDTLS: for now assuming that read/writes are blocking */
+       pitem *item;
+       hm_fragment *frag ;
+       unsigned long header_length;
+       unsigned char seq64be[8];
+       struct dtls1_retransmit_state saved_state;
+       unsigned char save_write_sequence[8];
+
+       /*
+         OPENSSL_assert(s->init_num == 0);
+         OPENSSL_assert(s->init_off == 0);
+        */
+
+       /* XDTLS:  the requested message ought to be found, otherwise error */
+       memset(seq64be,0,sizeof(seq64be));
+       seq64be[6] = (unsigned char)(seq>>8);
+       seq64be[7] = (unsigned char)seq;
+
+       item = pqueue_find(s->d1->sent_messages, seq64be);
+       if ( item == NULL)
+               {
+               fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
+               *found = 0;
+               return 0;
+               }
+
+       *found = 1;
+       frag = (hm_fragment *)item->data;
+
+       if ( frag->msg_header.is_ccs)
+               header_length = DTLS1_CCS_HEADER_LENGTH;
+       else
+               header_length = DTLS1_HM_HEADER_LENGTH;
+
+       memcpy(s->init_buf->data, frag->fragment, 
+               frag->msg_header.msg_len + header_length);
+               s->init_num = frag->msg_header.msg_len + header_length;
+
+       dtls1_set_message_header_int(s, frag->msg_header.type, 
+               frag->msg_header.msg_len, frag->msg_header.seq, 0, 
+               frag->msg_header.frag_len);
+
+       /* save current state */
+       saved_state.enc_write_ctx = s->enc_write_ctx;
+       saved_state.write_hash = s->write_hash;
+       saved_state.compress = s->compress;
+       saved_state.session = s->session;
+       saved_state.epoch = s->d1->w_epoch;
+       saved_state.epoch = s->d1->w_epoch;
+       
+       s->d1->retransmitting = 1;
+       
+       /* restore state in which the message was originally sent */
+       s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
+       s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
+       s->compress = frag->msg_header.saved_retransmit_state.compress;
+       s->session = frag->msg_header.saved_retransmit_state.session;
+       s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
+       
+       if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
+       {
+               memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
+               memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
+       }
+       
+       ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 
+                                                SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
+       
+       /* restore current state */
+       s->enc_write_ctx = saved_state.enc_write_ctx;
+       s->write_hash = saved_state.write_hash;
+       s->compress = saved_state.compress;
+       s->session = saved_state.session;
+       s->d1->w_epoch = saved_state.epoch;
+       
+       if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
+       {
+               memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
+               memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
+       }
+
+       s->d1->retransmitting = 0;
+
+       (void)BIO_flush(SSL_get_wbio(s));
+       return ret;
+       }
 
 /* call this function when the buffered messages are no longer needed */
 void
 dtls1_clear_record_buffer(SSL *s)
-    {
-    pitem *item;
-    
-    for(item = pqueue_pop(s->d1->sent_messages);
-        item != NULL; item = pqueue_pop(s->d1->sent_messages))
-        {
-        dtls1_hm_fragment_free((hm_fragment *)item->data);
-        pitem_free(item);
-        }
-    }
+       {
+       pitem *item;
+
+       for(item = pqueue_pop(s->d1->sent_messages);
+               item != NULL; item = pqueue_pop(s->d1->sent_messages))
+               {
+               dtls1_hm_fragment_free((hm_fragment *)item->data);
+               pitem_free(item);
+               }
+       }
 
 
 unsigned char *
 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
-    unsigned long len, unsigned long frag_off, unsigned long frag_len)
-    {
-    if ( frag_off == 0)
-        {
-        s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
-        s->d1->next_handshake_write_seq++;
-        }
-    
-    dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
-        frag_off, frag_len);
-    
-    return p += DTLS1_HM_HEADER_LENGTH;
-    }
+                       unsigned long len, unsigned long frag_off, unsigned long frag_len)
+       {
+       if ( frag_off == 0)
+               {
+               s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
+               s->d1->next_handshake_write_seq++;
+               }
+
+       dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
+               frag_off, frag_len);
+
+       return p += DTLS1_HM_HEADER_LENGTH;
+       }
 
 
 /* don't actually do the writing, wait till the MTU has been retrieved */
 static void
 dtls1_set_message_header_int(SSL *s, unsigned char mt,
-    unsigned long len, unsigned short seq_num, unsigned long frag_off, 
-    unsigned long frag_len)
-    {
-    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-    
-    msg_hdr->type = mt;
-    msg_hdr->msg_len = len;
-    msg_hdr->seq = seq_num;
-    msg_hdr->frag_off = frag_off;
-    msg_hdr->frag_len = frag_len;
-}
+                           unsigned long len, unsigned short seq_num, unsigned long frag_off,
+                           unsigned long frag_len)
+       {
+       struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+       msg_hdr->type = mt;
+       msg_hdr->msg_len = len;
+       msg_hdr->seq = seq_num;
+       msg_hdr->frag_off = frag_off;
+       msg_hdr->frag_len = frag_len;
+       }
 
 static void
 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
-       unsigned long frag_len)
-    {
-    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-    
-    msg_hdr->frag_off = frag_off;
-    msg_hdr->frag_len = frag_len;
-    }
+                       unsigned long frag_len)
+       {
+       struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+       msg_hdr->frag_off = frag_off;
+       msg_hdr->frag_len = frag_len;
+       }
 
 static unsigned char *
 dtls1_write_message_header(SSL *s, unsigned char *p)
-    {
-    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
-    
-    *p++ = msg_hdr->type;
-    l2n3(msg_hdr->msg_len, p);
-    
-    s2n(msg_hdr->seq, p);
-    l2n3(msg_hdr->frag_off, p);
-    l2n3(msg_hdr->frag_len, p);
-    
-    return p;
-    }
+       {
+       struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+       *p++ = msg_hdr->type;
+       l2n3(msg_hdr->msg_len, p);
+
+       s2n(msg_hdr->seq, p);
+       l2n3(msg_hdr->frag_off, p);
+       l2n3(msg_hdr->frag_len, p);
+
+       return p;
+       }
 
 static unsigned int 
 dtls1_min_mtu(void)
-    {
-    return 
-        g_probable_mtu[(sizeof(g_probable_mtu) / 
-           sizeof(g_probable_mtu[0])) - 1];
-    }
+       {
+       return (g_probable_mtu[(sizeof(g_probable_mtu) / 
+               sizeof(g_probable_mtu[0])) - 1]);
+       }
 
 static unsigned int 
 dtls1_guess_mtu(unsigned int curr_mtu)
        {
-       int i;
+       unsigned int i;
 
        if ( curr_mtu == 0 )
                return g_probable_mtu[0] ;
@@ -1237,27 +1212,26 @@ dtls1_guess_mtu(unsigned int curr_mtu)
        for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
                if ( curr_mtu > g_probable_mtu[i])
                        return g_probable_mtu[i];
-       
+
        return curr_mtu;
        }
 
 void
 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
-    {
-    memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
-    msg_hdr->type = *(data++);
-    n2l3(data, msg_hdr->msg_len);
-    
-    n2s(data, msg_hdr->seq);
-    n2l3(data, msg_hdr->frag_off);
-    n2l3(data, msg_hdr->frag_len);
-    }
+       {
+       memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
+       msg_hdr->type = *(data++);
+       n2l3(data, msg_hdr->msg_len);
+
+       n2s(data, msg_hdr->seq);
+       n2l3(data, msg_hdr->frag_off);
+       n2l3(data, msg_hdr->frag_len);
+       }
 
 void
 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
-    {
-    memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
-    
-    ccs_hdr->type = *(data++);
-    n2s(data, ccs_hdr->seq);
-}
+       {
+       memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
+
+       ccs_hdr->type = *(data++);
+       }