/*      $OpenBSD: chap.h,v 1.8 2002/09/13 00:12:10 deraadt Exp $        */

/*
 * chap.h - Challenge Handshake Authentication Protocol definitions.
 *
 * Copyright (c) 1989-2002 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission.
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Paul Mackerras
 *     <paulus@samba.org>".
 *
 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Copyright (c) 1991 Gregory M. Christy
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the author.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#ifndef __CHAP_INCLUDE__

/* Code + ID + length */
#define CHAP_HEADERLEN          4

/*
 * CHAP codes.
 */

#define CHAP_DIGEST_MD5         5       /* use MD5 algorithm */
#define MD5_SIGNATURE_SIZE      16      /* 16 bytes in a MD5 message digest */
#define CHAP_MICROSOFT          0x80    /* use Microsoft-compatible alg. */
#define MS_CHAP_RESPONSE_LEN    49      /* Response length for MS-CHAP */

#define CHAP_CHALLENGE          1
#define CHAP_RESPONSE           2
#define CHAP_SUCCESS            3
#define CHAP_FAILURE            4

/*
 *  Challenge lengths (for challenges we send) and other limits.
 */
#define MIN_CHALLENGE_LENGTH    32
#define MAX_CHALLENGE_LENGTH    64
#define MAX_RESPONSE_LENGTH     64      /* sufficient for MD5 or MS-CHAP */

/*
 * Each interface is described by a chap structure.
 */

typedef struct chap_state {
    int unit;                   /* Interface unit number */
    int clientstate;            /* Client state */
    int serverstate;            /* Server state */
    u_char challenge[MAX_CHALLENGE_LENGTH]; /* last challenge string sent */
    u_char chal_len;            /* challenge length */
    u_char chal_id;             /* ID of last challenge */
    u_char chal_type;           /* hash algorithm for challenges */
    u_char id;                  /* Current id */
    char *chal_name;            /* Our name to use with challenge */
    int chal_interval;          /* Time until we challenge peer again */
    int timeouttime;            /* Timeout time in seconds */
    int max_transmits;          /* Maximum # of challenge transmissions */
    int chal_transmits;         /* Number of transmissions of challenge */
    int resp_transmits;         /* Number of transmissions of response */
    u_char response[MAX_RESPONSE_LENGTH];       /* Response to send */
    u_char resp_length;         /* length of response */
    u_char resp_id;             /* ID for response messages */
    u_char resp_type;           /* hash algorithm for responses */
    char *resp_name;            /* Our name to send with response */
} chap_state;


/*
 * Client (peer) states.
 */
#define CHAPCS_INITIAL          0       /* Lower layer down, not opened */
#define CHAPCS_CLOSED           1       /* Lower layer up, not opened */
#define CHAPCS_PENDING          2       /* Auth us to peer when lower up */
#define CHAPCS_LISTEN           3       /* Listening for a challenge */
#define CHAPCS_RESPONSE         4       /* Sent response, waiting for status */
#define CHAPCS_OPEN             5       /* We've received Success */

/*
 * Server (authenticator) states.
 */
#define CHAPSS_INITIAL          0       /* Lower layer down, not opened */
#define CHAPSS_CLOSED           1       /* Lower layer up, not opened */
#define CHAPSS_PENDING          2       /* Auth peer when lower up */
#define CHAPSS_INITIAL_CHAL     3       /* We've sent the first challenge */
#define CHAPSS_OPEN             4       /* We've sent a Success msg */
#define CHAPSS_RECHALLENGE      5       /* We've sent another challenge */
#define CHAPSS_BADAUTH          6       /* We've sent a Failure msg */

/*
 * Timeouts.
 */
#define CHAP_DEFTIMEOUT         3       /* Timeout time in seconds */
#define CHAP_DEFTRANSMITS       10      /* max # times to send challenge */

extern chap_state chap[];

void ChapAuthWithPeer(int, char *, int);
void ChapAuthPeer(int, char *, int);

extern struct protent chap_protent;

#define __CHAP_INCLUDE__
#endif /* __CHAP_INCLUDE__ */