chap.h

/*
 * chap.h - Challenge Handshake Authentication Protocol definitions.
 *
 * 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.
 *
 * $Id$
 */

#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    16
#define MAX_CHALLENGE_LENGTH    24
#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     5   /* 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__ */