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. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 18 * 3. The name(s) of the authors of this software must not be used to 19 * endorse or promote products derived from this software without 20 * prior written permission. 21 * 22 * 4. Redistributions of any form whatsoever must retain the following 23 * acknowledgment: 24 * "This product includes software developed by Paul Mackerras 25 * <paulus@samba.org>". 26 * 27 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 28 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 29 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 30 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 31 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 32 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 33 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 34 */ 35 36/* 37 * CHAP packets begin with a standard header with code, id, len (2 bytes). 38 */ 39#define CHAP_HDRLEN 4 40 41/* 42 * Values for the code field. 43 */ 44#define CHAP_CHALLENGE 1 45#define CHAP_RESPONSE 2 46#define CHAP_SUCCESS 3 47#define CHAP_FAILURE 4 48 49/* 50 * CHAP digest codes. 51 */ 52#define CHAP_MD5 5 53#define CHAP_MICROSOFT 0x80 54#define CHAP_MICROSOFT_V2 0x81 55 56/* 57 * Semi-arbitrary limits on challenge and response fields. 58 */ 59#define MAX_CHALLENGE_LEN 64 60#define MAX_RESPONSE_LEN 64 61 62/* bitmask of supported algorithms */ 63#define MDTYPE_MICROSOFT_V2 0x1 64#define MDTYPE_MICROSOFT 0x2 65#define MDTYPE_MD5 0x4 66 67#ifdef CHAPMS 68#define MDTYPE_ALL (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT | MDTYPE_MD5) 69#else 70#define MDTYPE_ALL (MDTYPE_MD5) 71#endif 72#define MDTYPE_NONE 0 73 74/* Return the digest alg. ID for the most preferred digest type. */ 75#define CHAP_DIGEST(mdtype) \ 76 ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \ 77 ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \ 78 ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \ 79 0 80 81/* Return the bit flag (lsb set) for our most preferred digest type. */ 82#define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype) 83 84/* Return the bit flag for a given digest algorithm ID. */ 85#define CHAP_MDTYPE_D(digest) \ 86 ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \ 87 ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \ 88 ((digest) == CHAP_MD5)? MDTYPE_MD5: \ 89 0 90 91/* Can we do the requested digest? */ 92#define CHAP_CANDIGEST(mdtype, digest) \ 93 ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \ 94 ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \ 95 ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \ 96 0 97 98/* 99 * The code for each digest type has to supply one of these. 100 */ 101struct chap_digest_type { 102 int code; 103 104 /* 105 * Note: challenge and response arguments below are formatted as 106 * a length byte followed by the actual challenge/response data. 107 */ 108 void (*generate_challenge)(unsigned char *challenge); 109 int (*verify_response)(int id, char *name, 110 unsigned char *secret, int secret_len, 111 unsigned char *challenge, unsigned char *response, 112 char *message, int message_space); 113 void (*make_response)(unsigned char *response, int id, char *our_name, 114 unsigned char *challenge, char *secret, int secret_len, 115 unsigned char *priv); 116 int (*check_success)(unsigned char *pkt, int len, unsigned char *priv); 117 void (*handle_failure)(unsigned char *pkt, int len); 118 119 struct chap_digest_type *next; 120}; 121 122/* Hook for a plugin to validate CHAP challenge */ 123extern int (*chap_verify_hook)(char *name, char *ourname, int id, 124 struct chap_digest_type *digest, 125 unsigned char *challenge, unsigned char *response, 126 unsigned char *message, int message_space); 127 128/* Called by digest code to register a digest type */ 129extern void chap_register_digest(struct chap_digest_type *); 130 131/* Called by authentication code to start authenticating the peer. */ 132extern void chap_auth_peer(int unit, char *our_name, int digest_code); 133 134/* Called by auth. code to start authenticating us to the peer. */ 135extern void chap_auth_with_peer(int unit, char *our_name, int digest_code); 136 137/* Represents the CHAP protocol to the main pppd code */ 138extern struct protent chap_protent; 139