/*
 * chap.h - Cryptographic Handshake Authentication Protocol definitions.
 *
 * 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 1.2 1994/04/11 07:13:44 paulus Exp $
 */

#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_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	16	/* sufficient for MD5 */

/*
 * 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 ChapInit __ARGS((int));
void ChapAuthWithPeer __ARGS((int, char *, int));
void ChapAuthPeer __ARGS((int, char *, int));
void ChapLowerUp __ARGS((int));
void ChapLowerDown __ARGS((int));
void ChapInput __ARGS((int, u_char *, int));
void ChapProtocolReject __ARGS((int));
int  ChapPrintPkt __ARGS((u_char *, int,
			  void (*) __ARGS((void *, char *, ...)), void *));

#define __CHAP_INCLUDE__
#endif /* __CHAP_INCLUDE__ */
