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/*
* chap-new.c - New CHAP implementation.
*
* Copyright (c) 2003 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. 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.
*
* 3. 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.
*/
/*
* 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
/*
* CHAP digest codes.
*/
#define CHAP_MD5 5
#define CHAP_MICROSOFT 0x80
#define CHAP_MICROSOFT_V2 0x81
/*
* Semi-arbitrary limits on challenge and response fields.
*/
#define MAX_CHALLENGE_LEN 64
#define MAX_RESPONSE_LEN 64
/* bitmask of supported algorithms */
#define MDTYPE_MICROSOFT_V2 0x1
#define MDTYPE_MICROSOFT 0x2
#define MDTYPE_MD5 0x4
#define MDTYPE_NONE 0
/* 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;
};
/* Hook for a plugin to validate CHAP challenge */
extern int (*chap_verify_hook)(char *name, char *ourname, int id,
struct chap_digest_type *digest,
unsigned char *challenge, unsigned char *response,
char *message, int message_space);
/* Called by digest code to register a digest type */
extern void chap_register_digest(struct chap_digest_type *);
/* 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;
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