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 #include "netif/ppp/ppp_opts.h" 32 #if PPP_SUPPORT && CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */ 33 34 #ifndef CHAP_H 35 #define CHAP_H 36 37 #include "ppp.h" 38 39 /* 40 * CHAP packets begin with a standard header with code, id, len (2 bytes). 41 */ 42 #define CHAP_HDRLEN 4 43 44 /* 45 * Values for the code field. 46 */ 47 #define CHAP_CHALLENGE 1 48 #define CHAP_RESPONSE 2 49 #define CHAP_SUCCESS 3 50 #define CHAP_FAILURE 4 51 52 /* 53 * CHAP digest codes. 54 */ 55 #define CHAP_MD5 5 56 #if MSCHAP_SUPPORT 57 #define CHAP_MICROSOFT 0x80 58 #define CHAP_MICROSOFT_V2 0x81 59 #endif /* MSCHAP_SUPPORT */ 60 61 /* 62 * Semi-arbitrary limits on challenge and response fields. 63 */ 64 #define MAX_CHALLENGE_LEN 64 65 #define MAX_RESPONSE_LEN 64 66 67 /* 68 * These limits apply to challenge and response packets we send. 69 * The +4 is the +1 that we actually need rounded up. 70 */ 71 #define CHAL_MAX_PKTLEN (PPP_HDRLEN + CHAP_HDRLEN + 4 + MAX_CHALLENGE_LEN + MAXNAMELEN) 72 #define RESP_MAX_PKTLEN (PPP_HDRLEN + CHAP_HDRLEN + 4 + MAX_RESPONSE_LEN + MAXNAMELEN) 73 74 /* bitmask of supported algorithms */ 75 #if MSCHAP_SUPPORT 76 #define MDTYPE_MICROSOFT_V2 0x1 77 #define MDTYPE_MICROSOFT 0x2 78 #endif /* MSCHAP_SUPPORT */ 79 #define MDTYPE_MD5 0x4 80 #define MDTYPE_NONE 0 81 82 #if MSCHAP_SUPPORT 83 /* Return the digest alg. ID for the most preferred digest type. */ 84 #define CHAP_DIGEST(mdtype) \ 85 ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \ 86 ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \ 87 ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \ 88 0 89 #else /* !MSCHAP_SUPPORT */ 90 #define CHAP_DIGEST(mdtype) \ 91 ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \ 92 0 93 #endif /* MSCHAP_SUPPORT */ 94 95 /* Return the bit flag (lsb set) for our most preferred digest type. */ 96 #define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype) 97 98 /* Return the bit flag for a given digest algorithm ID. */ 99 #if MSCHAP_SUPPORT 100 #define CHAP_MDTYPE_D(digest) \ 101 ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \ 102 ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \ 103 ((digest) == CHAP_MD5)? MDTYPE_MD5: \ 104 0 105 #else /* !MSCHAP_SUPPORT */ 106 #define CHAP_MDTYPE_D(digest) \ 107 ((digest) == CHAP_MD5)? MDTYPE_MD5: \ 108 0 109 #endif /* MSCHAP_SUPPORT */ 110 111 /* Can we do the requested digest? */ 112 #if MSCHAP_SUPPORT 113 #define CHAP_CANDIGEST(mdtype, digest) \ 114 ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \ 115 ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \ 116 ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \ 117 0 118 #else /* !MSCHAP_SUPPORT */ 119 #define CHAP_CANDIGEST(mdtype, digest) \ 120 ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \ 121 0 122 #endif /* MSCHAP_SUPPORT */ 123 124 /* 125 * The code for each digest type has to supply one of these. 126 */ 127 struct chap_digest_type { 128 int code; 129 130 #if PPP_SERVER 131 /* 132 * Note: challenge and response arguments below are formatted as 133 * a length byte followed by the actual challenge/response data. 134 */ 135 void (*generate_challenge)(ppp_pcb *pcb, unsigned char *challenge); 136 int (*verify_response)(ppp_pcb *pcb, int id, const char *name, 137 const unsigned char *secret, int secret_len, 138 const unsigned char *challenge, const unsigned char *response, 139 char *message, int message_space); 140 #endif /* PPP_SERVER */ 141 void (*make_response)(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name, 142 const unsigned char *challenge, const char *secret, int secret_len, 143 unsigned char *priv); 144 int (*check_success)(ppp_pcb *pcb, unsigned char *pkt, int len, unsigned char *priv); 145 void (*handle_failure)(ppp_pcb *pcb, unsigned char *pkt, int len); 146 }; 147 148 /* 149 * Each interface is described by chap structure. 150 */ 151 #if CHAP_SUPPORT 152 typedef struct chap_client_state { 153 u8_t flags; 154 const char *name; 155 const struct chap_digest_type *digest; 156 unsigned char priv[64]; /* private area for digest's use */ 157 } chap_client_state; 158 159 #if PPP_SERVER 160 typedef struct chap_server_state { 161 u8_t flags; 162 u8_t id; 163 const char *name; 164 const struct chap_digest_type *digest; 165 int challenge_xmits; 166 int challenge_pktlen; 167 unsigned char challenge[CHAL_MAX_PKTLEN]; 168 } chap_server_state; 169 #endif /* PPP_SERVER */ 170 #endif /* CHAP_SUPPORT */ 171 172 #if 0 /* UNUSED */ 173 /* Hook for a plugin to validate CHAP challenge */ 174 extern int (*chap_verify_hook)(char *name, char *ourname, int id, 175 const struct chap_digest_type *digest, 176 unsigned char *challenge, unsigned char *response, 177 char *message, int message_space); 178 #endif /* UNUSED */ 179 180 #if PPP_SERVER 181 /* Called by authentication code to start authenticating the peer. */ 182 extern void chap_auth_peer(ppp_pcb *pcb, const char *our_name, int digest_code); 183 #endif /* PPP_SERVER */ 184 185 /* Called by auth. code to start authenticating us to the peer. */ 186 extern void chap_auth_with_peer(ppp_pcb *pcb, const char *our_name, int digest_code); 187 188 /* Represents the CHAP protocol to the main pppd code */ 189 extern const struct protent chap_protent; 190 191 #endif /* CHAP_H */ 192 #endif /* PPP_SUPPORT && CHAP_SUPPORT */ 193