openssl/ssl/dtls1.h

/* 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>
# 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_2_VERSION                 0xFEFD
# define DTLS_MAX_VERSION                DTLS1_2_VERSION

# define DTLS1_BAD_VER                   0x0100

/* Special value for method supporting multiple versions */
# define DTLS_ANY_VERSION                0x1FFFF

# 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

/* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
#  define DTLS1_MAX_MTU_OVERHEAD                   48

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 link_mtu;      /* max on-the-wire DTLS packet size */
    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;
    /*
     * Set when the handshake is ready to process peer's ChangeCipherSpec message.
     * Cleared after the message has been processed.
     */
    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