1/* 2 * chap-new.c - New CHAP implementation. 3 * 4 * Copyright (c) 2003 Paul Mackerras. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. The name(s) of the authors of this software must not be used to 14 * endorse or promote products derived from this software without 15 * prior written permission. 16 * 17 * 3. Redistributions of any form whatsoever must retain the following 18 * acknowledgment: 19 * "This product includes software developed by Paul Mackerras 20 * <paulus@samba.org>". 21 * 22 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 23 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 24 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 25 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 26 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 27 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 28 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 29 */ 30 31/* 32 * CHAP packets begin with a standard header with code, id, len (2 bytes). 33 */ 34#define CHAP_HDRLEN 4 35 36/* 37 * Values for the code field. 38 */ 39#define CHAP_CHALLENGE 1 40#define CHAP_RESPONSE 2 41#define CHAP_SUCCESS 3 42#define CHAP_FAILURE 4 43 44/* 45 * CHAP digest codes. 46 */ 47#define CHAP_MD5 5 48#define CHAP_MICROSOFT 0x80 49#define CHAP_MICROSOFT_V2 0x81 50 51/* 52 * Semi-arbitrary limits on challenge and response fields. 53 */ 54#define MAX_CHALLENGE_LEN 64 55#define MAX_RESPONSE_LEN 64 56 57/* bitmask of supported algorithms */ 58#define MDTYPE_MICROSOFT_V2 0x1 59#define MDTYPE_MD5 0x2 60#define MDTYPE_MICROSOFT 0x4 61#define MDTYPE_NONE 0 62 63/* hashes supported by this instance of pppd */ 64extern int chap_mdtype_all; 65 66/* Return the digest alg. ID for the most preferred digest type. */ 67#define CHAP_DIGEST(mdtype) \ 68 ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \ 69 ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \ 70 ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \ 71 0 72 73/* Return the bit flag (lsb set) for our most preferred digest type. */ 74#define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype) 75 76/* Return the bit flag for a given digest algorithm ID. */ 77#define CHAP_MDTYPE_D(digest) \ 78 ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \ 79 ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \ 80 ((digest) == CHAP_MD5)? MDTYPE_MD5: \ 81 0 82 83/* Can we do the requested digest? */ 84#define CHAP_CANDIGEST(mdtype, digest) \ 85 ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \ 86 ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \ 87 ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \ 88 0 89 90/* 91 * The code for each digest type has to supply one of these. 92 */ 93struct chap_digest_type { 94 int code; 95 96 /* 97 * Note: challenge and response arguments below are formatted as 98 * a length byte followed by the actual challenge/response data. 99 */ 100 void (*generate_challenge)(unsigned char *challenge); 101 int (*verify_response)(int id, char *name, 102 unsigned char *secret, int secret_len, 103 unsigned char *challenge, unsigned char *response, 104 char *message, int message_space); 105 void (*make_response)(unsigned char *response, int id, char *our_name, 106 unsigned char *challenge, char *secret, int secret_len); 107 int (*check_success)(int id, unsigned char *pkt, int len); 108 void (*handle_failure)(unsigned char *pkt, int len); 109 110 struct chap_digest_type *next; 111}; 112 113/* Hook for a plugin to validate CHAP challenge */ 114extern int (*chap_verify_hook)(char *name, char *ourname, int id, 115 struct chap_digest_type *digest, 116 unsigned char *challenge, unsigned char *response, 117 char *message, int message_space); 118 119/* Called by digest code to register a digest type */ 120extern void chap_register_digest(struct chap_digest_type *); 121 122/* Called by authentication code to start authenticating the peer. */ 123extern void chap_auth_peer(int unit, char *our_name, int digest_code); 124 125/* Called by auth. code to start authenticating us to the peer. */ 126extern void chap_auth_with_peer(int unit, char *our_name, int digest_code); 127 128/* Represents the CHAP protocol to the main pppd code */ 129extern struct protent chap_protent; 130