]> WPIA git - cassiopeia.git/blobdiff - lib/openssl/ssl/d1_pkt.c
add: execute openssl fetcher to fetch openssl 1.0.1j
[cassiopeia.git] / lib / openssl / ssl / d1_pkt.c
diff --git a/lib/openssl/ssl/d1_pkt.c b/lib/openssl/ssl/d1_pkt.c
new file mode 100644 (file)
index 0000000..438c091
--- /dev/null
@@ -0,0 +1,1901 @@
+/* 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);
+
+/* 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;
+
+#ifndef OPENSSL_NO_SCTP
+       /* Store bio_dgram_sctp_rcvinfo struct */
+       if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+           (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
+               BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
+       }
+#endif
+
+       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);
+               }
+
+       /* insert should not fail, since duplicates are dropped */
+       if (pqueue_insert(queue->q, item) == NULL)
+               {
+               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 enc_err;
+       SSL_SESSION *sess;
+       SSL3_RECORD *rr;
+       unsigned int mac_size, orig_len;
+       unsigned char md[EVP_MAX_MD_SIZE];
+
+       rr= &(s->s3->rrec);
+       sess = s->session;
+
+       /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
+        * and we have that many bytes in s->packet
+        */
+       rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
+
+       /* ok, we can now read from 's->packet' data into 'rr'
+        * rr->input points at rr->length bytes, which
+        * need to be copied into rr->data by either
+        * the decryption or by the decompression
+        * When the data is 'copied' into the rr->data buffer,
+        * rr->input will be pointed at the new buffer */ 
+
+       /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
+        * rr->length bytes of encrypted compressed stuff. */
+
+       /* check is not needed I believe */
+       if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
+               {
+               al=SSL_AD_RECORD_OVERFLOW;
+               SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
+               goto f_err;
+               }
+
+       /* decrypt in place in 'rr->input' */
+       rr->data=rr->input;
+
+       enc_err = s->method->ssl3_enc->enc(s,0);
+       /* enc_err is:
+        *    0: (in non-constant time) if the record is publically invalid.
+        *    1: if the padding is valid
+        *    -1: if the padding is invalid */
+       if (enc_err == 0)
+               {
+               /* For DTLS we simply ignore bad packets. */
+               rr->length = 0;
+               s->packet_length = 0;
+               goto err;
+               }
+
+#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) &&
+           (EVP_MD_CTX_md(s->read_hash) != NULL))
+               {
+               /* s->read_hash != NULL => mac_size != -1 */
+               unsigned char *mac = NULL;
+               unsigned char mac_tmp[EVP_MAX_MD_SIZE];
+               mac_size=EVP_MD_CTX_size(s->read_hash);
+               OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+               /* kludge: *_cbc_remove_padding passes padding length in rr->type */
+               orig_len = rr->length+((unsigned int)rr->type>>8);
+
+               /* orig_len is the length of the record before any padding was
+                * removed. This is public information, as is the MAC in use,
+                * therefore we can safely process the record in a different
+                * amount of time if it's too short to possibly contain a MAC.
+                */
+               if (orig_len < mac_size ||
+                   /* CBC records must have a padding length byte too. */
+                   (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+                    orig_len < mac_size+1))
+                       {
+                       al=SSL_AD_DECODE_ERROR;
+                       SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
+                       goto f_err;
+                       }
+
+               if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
+                       {
+                       /* We update the length so that the TLS header bytes
+                        * can be constructed correctly but we need to extract
+                        * the MAC in constant time from within the record,
+                        * without leaking the contents of the padding bytes.
+                        * */
+                       mac = mac_tmp;
+                       ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
+                       rr->length -= mac_size;
+                       }
+               else
+                       {
+                       /* In this case there's no padding, so |orig_len|
+                        * equals |rec->length| and we checked that there's
+                        * enough bytes for |mac_size| above. */
+                       rr->length -= mac_size;
+                       mac = &rr->data[rr->length];
+                       }
+
+               i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
+               if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
+                       enc_err = -1;
+               if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
+                       enc_err = -1;
+               }
+
+       if (enc_err < 0)
+               {
+               /* 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 */
+               }
+
+#ifndef OPENSSL_NO_SCTP
+       /* Only do replay check if no SCTP bio */
+       if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
+               {
+#endif
+               /* 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 */
+                       }
+#ifndef OPENSSL_NO_SCTP
+               }
+#endif
+
+       /* 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 */
+               }
+
+       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. */
+
+#ifndef OPENSSL_NO_SCTP
+       /* Continue handshake if it had to be interrupted to read
+        * app data with SCTP.
+        */
+       if ((!s->in_handshake && SSL_in_init(s)) ||
+           (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+            (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
+            s->s3->in_read_app_data != 2))
+#else
+       if (!s->in_handshake && SSL_in_init(s))
+#endif
+               {
+               /* 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)
+                       {
+#ifndef OPENSSL_NO_SCTP
+                       /* Restore bio_dgram_sctp_rcvinfo struct */
+                       if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
+                               {
+                               DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
+                               BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
+                               }
+#endif
+
+                       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;
+                       }
+               }
+
+       if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
+               {
+               rr->length = 0;
+               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;
+                               }
+                       }
+
+#ifndef OPENSSL_NO_SCTP
+                       /* We were about to renegotiate but had to read
+                        * belated application data first, so retry.
+                        */
+                       if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+                           rr->type == SSL3_RT_APPLICATION_DATA &&
+                           (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
+                               {
+                               s->rwstate=SSL_READING;
+                               BIO_clear_retry_flags(SSL_get_rbio(s));
+                               BIO_set_retry_read(SSL_get_rbio(s));
+                               }
+
+                       /* We might had to delay a close_notify alert because
+                        * of reordered app data. If there was an alert and there
+                        * is no message to read anymore, finally set shutdown.
+                        */
+                       if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+                           s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
+                               {
+                               s->shutdown |= SSL_RECEIVED_SHUTDOWN;
+                               return(0);
+                               }
+#endif                 
+               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;
+                       }
+#ifndef OPENSSL_NO_HEARTBEATS
+               else if (rr->type == TLS1_RT_HEARTBEAT)
+                       {
+                       dtls1_process_heartbeat(s);
+
+                       /* Exit and notify application to read again */
+                       rr->length = 0;
+                       s->rwstate=SSL_READING;
+                       BIO_clear_retry_flags(SSL_get_rbio(s));
+                       BIO_set_retry_read(SSL_get_rbio(s));
+                       return(-1);
+                       }
+#endif
+               /* 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)
+                       {
+                       s->d1->handshake_read_seq++;
+                       s->new_session = 1;
+                       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)
+                               {
+#ifndef OPENSSL_NO_SCTP
+                               /* With SCTP and streams the socket may deliver app data
+                                * after a close_notify alert. We have to check this
+                                * first so that nothing gets discarded.
+                                */
+                               if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+                                       BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
+                                       {
+                                       s->d1->shutdown_received = 1;
+                                       s->rwstate=SSL_READING;
+                                       BIO_clear_retry_flags(SSL_get_rbio(s));
+                                       BIO_set_retry_read(SSL_get_rbio(s));
+                                       return -1;
+                                       }
+#endif
+                               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++;
+
+#ifndef OPENSSL_NO_SCTP
+               /* Remember that a CCS has been received,
+                * so that an old key of SCTP-Auth can be
+                * deleted when a CCS is sent. Will be ignored
+                * if no SCTP is used
+                */
+               BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
+#endif
+
+               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)
+                       {
+                       if (dtls1_check_timeout_num(s) < 0)
+                               return -1;
+
+                       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->renegotiate=1;
+                       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;
+
+#ifndef OPENSSL_NO_SCTP
+               /* Check if we have to continue an interrupted handshake
+                * for reading belated app data with SCTP.
+                */
+               if ((SSL_in_init(s) && !s->in_handshake) ||
+                   (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+                    (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
+#else
+               if (SSL_in_init(s) && !s->in_handshake)
+#endif
+               {
+               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);
+       }