text: /* ssl/dtls1.h */
  /* 
   * DTLS implementation written by Nagendra Modadugu
   * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
   */
  /* ====================================================================
   * Copyright (c) 1999-2005 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).
   *
   */
  
  #ifndef HEADER_DTLS1_H
  #define HEADER_DTLS1_H
  
  #include <openssl/buffer.h>
  #include <openssl/pqueue.h>
  #ifdef OPENSSL_SYS_VMS
  #include <resource.h>
  #include <sys/timeb.h>
  #endif
  #ifdef OPENSSL_SYS_WIN32
  /* Needed for struct timeval */
  #include <winsock.h>
  #ifdef X509_NAME
  #undef X509_NAME
  #endif
  #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
  #include <sys/timeval.h>
  #else
  #if defined(OPENSSL_SYS_VXWORKS)
  #include <sys/times.h>
  #else
  #include <sys/time.h>
  #endif
  #endif
  
  #ifdef  __cplusplus
  extern "C" {
  #endif
  
  #define DTLS1_VERSION			0xFEFF
  #define DTLS1_BAD_VER			0x0100
  
  #if 0
  /* this alert description is not specified anywhere... */
  #define DTLS1_AD_MISSING_HANDSHAKE_MESSAGE    110
  #endif
  
  /* lengths of messages */
  #define DTLS1_COOKIE_LENGTH                     256
  
  #define DTLS1_RT_HEADER_LENGTH                  13
  
  #define DTLS1_HM_HEADER_LENGTH                  12
  
  #define DTLS1_HM_BAD_FRAGMENT                   -2
  #define DTLS1_HM_FRAGMENT_RETRY                 -3
  
  #define DTLS1_CCS_HEADER_LENGTH                  1
  
  #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
  #define DTLS1_AL_HEADER_LENGTH                   7
  #else
  #define DTLS1_AL_HEADER_LENGTH                   2
  #endif
  
  #ifndef OPENSSL_NO_SSL_INTERN
  
  #ifndef OPENSSL_NO_SCTP
  #define DTLS1_SCTP_AUTH_LABEL	"EXPORTER_DTLS_OVER_SCTP"
  #endif
  
  typedef struct dtls1_bitmap_st
  	{
  	unsigned long map;		/* track 32 packets on 32-bit systems
  					   and 64 - on 64-bit systems */
  	unsigned char max_seq_num[8];	/* max record number seen so far,
  					   64-bit value in big-endian
  					   encoding */
  	} DTLS1_BITMAP;
  
  struct dtls1_retransmit_state
  	{
  	EVP_CIPHER_CTX *enc_write_ctx;	/* cryptographic state */
  	EVP_MD_CTX *write_hash;			/* used for mac generation */
  #ifndef OPENSSL_NO_COMP
  	COMP_CTX *compress;				/* compression */
  #else
  	char *compress;	
  #endif
  	SSL_SESSION *session;
  	unsigned short epoch;
  	};
  
  struct hm_header_st
  	{
  	unsigned char type;
  	unsigned long msg_len;
  	unsigned short seq;
  	unsigned long frag_off;
  	unsigned long frag_len;
  	unsigned int is_ccs;
  	struct dtls1_retransmit_state saved_retransmit_state;
  	};
  
  struct ccs_header_st
  	{
  	unsigned char type;
  	unsigned short seq;
  	};
  
  struct dtls1_timeout_st
  	{
  	/* Number of read timeouts so far */
  	unsigned int read_timeouts;
  	
  	/* Number of write timeouts so far */
  	unsigned int write_timeouts;
  	
  	/* Number of alerts received so far */
  	unsigned int num_alerts;
  	};
  
  typedef struct record_pqueue_st
  	{
  	unsigned short epoch;
  	pqueue q;
  	} record_pqueue;
  
  typedef struct hm_fragment_st
  	{
  	struct hm_header_st msg_header;
  	unsigned char *fragment;
  	unsigned char *reassembly;
  	} hm_fragment;
  
  typedef struct dtls1_state_st
  	{
  	unsigned int send_cookie;
  	unsigned char cookie[DTLS1_COOKIE_LENGTH];
  	unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
  	unsigned int cookie_len;
  
  	/* 
  	 * The current data and handshake epoch.  This is initially
  	 * undefined, and starts at zero once the initial handshake is
  	 * completed 
  	 */
  	unsigned short r_epoch;
  	unsigned short w_epoch;
  
  	/* records being received in the current epoch */
  	DTLS1_BITMAP bitmap;
  
  	/* renegotiation starts a new set of sequence numbers */
  	DTLS1_BITMAP next_bitmap;
  
  	/* handshake message numbers */
  	unsigned short handshake_write_seq;
  	unsigned short next_handshake_write_seq;
  
  	unsigned short handshake_read_seq;
  
  	/* save last sequence number for retransmissions */
  	unsigned char last_write_sequence[8];
  
  	/* Received handshake records (processed and unprocessed) */
  	record_pqueue unprocessed_rcds;
  	record_pqueue processed_rcds;
  
  	/* Buffered handshake messages */
  	pqueue buffered_messages;
  
  	/* Buffered (sent) handshake records */
  	pqueue sent_messages;
  
  	/* Buffered application records.
  	 * Only for records between CCS and Finished
  	 * to prevent either protocol violation or
  	 * unnecessary message loss.
  	 */
  	record_pqueue buffered_app_data;
  
  	/* Is set when listening for new connections with dtls1_listen() */
  	unsigned int listen;
  
  	unsigned int mtu; /* max DTLS packet size */
  
  	struct hm_header_st w_msg_hdr;
  	struct hm_header_st r_msg_hdr;
  
  	struct dtls1_timeout_st timeout;
  
  	/* Indicates when the last handshake msg or heartbeat sent will timeout */
  	struct timeval next_timeout;
  
  	/* Timeout duration */
  	unsigned short timeout_duration;
  
  	/* storage for Alert/Handshake protocol data received but not
  	 * yet processed by ssl3_read_bytes: */
  	unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
  	unsigned int alert_fragment_len;
  	unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
  	unsigned int handshake_fragment_len;
  
  	unsigned int retransmitting;
  	unsigned int change_cipher_spec_ok;
  
  #ifndef OPENSSL_NO_SCTP
  	/* used when SSL_ST_XX_FLUSH is entered */
  	int next_state;
  
  	int shutdown_received;
  #endif
  
  	} DTLS1_STATE;
  
  typedef struct dtls1_record_data_st
  	{
  	unsigned char *packet;
  	unsigned int   packet_length;
  	SSL3_BUFFER    rbuf;
  	SSL3_RECORD    rrec;
  #ifndef OPENSSL_NO_SCTP
  	struct bio_dgram_sctp_rcvinfo recordinfo;
  #endif
  	} DTLS1_RECORD_DATA;
  
  #endif
  
  /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
  #define DTLS1_TMO_READ_COUNT                      2
  #define DTLS1_TMO_WRITE_COUNT                     2
  
  #define DTLS1_TMO_ALERT_COUNT                     12
  
  #ifdef  __cplusplus
  }
  #endif
  #endif
  
  