/*
 * chap.h - Challenge Handshake Authentication Protocol definitions.
 *
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 1993 The Australian National University.
 * 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 Australian National University.  The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * 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.
 *
 * 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.
 *
 * $Id: chap.h,v 1.8 1999/11/15 01:44:41 paulus Exp $
 */

#ifndef __CHAP_INCLUDE__
#define __CHAP_INCLUDE__

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

#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 CHAP_MICROSOFT_V2       0x81    /* use MS-CHAPv2 */

#define CHECK_CHALLENGE_LENGTH  8       /* Minimum acceptable challenge */

/*
 * CHAP message code numbers.
 */
#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    16
#define MAX_CHALLENGE_LENGTH    24
#define MAX_RESPONSE_LENGTH     64      /* sufficient for MD5 or MS-CHAP */
/* These are here to remind people of the buffer limits */
#define MS_CHAP_RESPONSE_LEN    49      /* Response length for MS-CHAP */
#define MS_CHAPV2_RESPONSE_LEN  49      /* Response length for MS-CHAPv2 */

/*
 * 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 */
    char peercname[MAXNAMELEN]; /* unauthenticated peer name in challenge */
    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 */
    u_char stat_length;         /* Length of status message (MS-CHAP) */
    char *resp_name;            /* Our name to send with response */
    char *stat_message;         /* per-algorithm status message (MS-CHAP) */
    int rename_count;           /* number of peer renames seen */
} chap_state;


/*
 * Client (authenticatee) 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 */

#define CHAPCS__LIST    \
        "Initial", "Closed", "Pending", "Listen", \
        "Response", "Open"

/*
 * 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 */

#define CHAPSS__LIST    \
        "Initial", "Closed", "Pending", "InitialChal", \
        "Open", "Rechallenge", "BadAuth"

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

extern chap_state chap[];

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

extern struct protent chap_protent;

#endif /* __CHAP_INCLUDE__ */