/*
* chap.h - New CHAP implementation.
*
* Copyright (c) 2003-2024 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.
*
* 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.
*/
#ifndef PPP_CHAP_NEW_H
#define PPP_CHAP_NEW_H
#include "pppdconf.h"
#ifdef __cplusplus
extern "C" {
#endif
/*
* CHAP packets begin with a standard header with code, id, len (2 bytes).
*/
#define CHAP_HDRLEN 4
/*
* Values for the code field.
*/
#define CHAP_CHALLENGE 1
#define CHAP_RESPONSE 2
#define CHAP_SUCCESS 3
#define CHAP_FAILURE 4
/* hashes supported by this instance of pppd */
extern int chap_mdtype_all;
/* Return the digest alg. ID for the most preferred digest type. */
#define CHAP_DIGEST(mdtype) \
((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
0
/* Return the bit flag (lsb set) for our most preferred digest type. */
#define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
/* Return the bit flag for a given digest algorithm ID. */
#define CHAP_MDTYPE_D(digest) \
((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
((digest) == CHAP_MD5)? MDTYPE_MD5: \
0
/* Can we do the requested digest? */
#define CHAP_CANDIGEST(mdtype, digest) \
((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
0
/*
* The code for each digest type has to supply one of these.
*/
struct chap_digest_type {
int code;
/*
* Note: challenge and response arguments below are formatted as
* a length byte followed by the actual challenge/response data.
*/
void (*generate_challenge)(unsigned char *challenge);
int (*verify_response)(int id, char *name,
unsigned char *secret, int secret_len,
unsigned char *challenge, unsigned char *response,
char *message, int message_space);
void (*make_response)(unsigned char *response, int id, char *our_name,
unsigned char *challenge, char *secret, int secret_len,
unsigned char *priv);
int (*check_success)(int id, unsigned char *pkt, int len);
void (*handle_failure)(unsigned char *pkt, int len);
struct chap_digest_type *next;
};
/*
* This function will return a value of 1 to indicate that a plugin intend to supply
* a username or a password to pppd through the chap_passwd_hook callback.
*
* Return a value > 0 to avoid parsing the chap-secrets file.
*/
typedef int (chap_check_hook_fn)(void);
extern chap_check_hook_fn *chap_check_hook;
/*
* A plugin can chose to supply its own user and password overriding whatever
* has been provided by the configuration. Hook is only valid when pppd is
* acting as a client.
*
* The maximum size of the user argument is always MAXNAMELEN
* The length of the password is always MAXWORDLEN, however; secrets can't be
* longer than MAXSECRETLEN
*
* Return a value < 0 to fail the connection.
*/
typedef int (chap_passwd_hook_fn)(char *user, char *password);
extern chap_passwd_hook_fn *chap_passwd_hook;
/*
* A plugin can chose to replace the default chap_verify_response function with
* one of their own.
*/
typedef int (chap_verify_hook_fn)(char *name, char *ourname, int id,
struct chap_digest_type *digest,
unsigned char *challenge, unsigned char *response,
char *message, int message_space);
extern chap_verify_hook_fn *chap_verify_hook;
/* Called by digest code to register a digest type */
extern void chap_register_digest(struct chap_digest_type *);
/* Lookup a digest handler by type */
extern struct chap_digest_type *chap_find_digest(int digest_code);
/* Called by authentication code to start authenticating the peer. */
extern void chap_auth_peer(int unit, char *our_name, int digest_code);
/* Called by auth. code to start authenticating us to the peer. */
extern void chap_auth_with_peer(int unit, char *our_name, int digest_code);
/* Represents the CHAP protocol to the main pppd code */
extern struct protent chap_protent;
