2 * chap-new.c - New CHAP implementation.
4 * Copyright (c) 2003 Paul Mackerras. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
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.
17 * 3. Redistributions of any form whatsoever must retain the following
19 * "This product includes software developed by Paul Mackerras
20 * <paulus@samba.org>".
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.
34 * CHAP packets begin with a standard header with code, id, len (2 bytes).
39 * Values for the code field.
41 #define CHAP_CHALLENGE 1
42 #define CHAP_RESPONSE 2
43 #define CHAP_SUCCESS 3
44 #define CHAP_FAILURE 4
50 #define CHAP_MICROSOFT 0x80
51 #define CHAP_MICROSOFT_V2 0x81
54 * Semi-arbitrary limits on challenge and response fields.
56 #define MAX_CHALLENGE_LEN 64
57 #define MAX_RESPONSE_LEN 64
59 /* bitmask of supported algorithms */
60 #define MDTYPE_MICROSOFT_V2 0x1
61 #define MDTYPE_MICROSOFT 0x2
62 #define MDTYPE_MD5 0x4
65 /* hashes supported by this instance of pppd */
66 extern int chap_mdtype_all;
68 /* Return the digest alg. ID for the most preferred digest type. */
69 #define CHAP_DIGEST(mdtype) \
70 ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
71 ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
72 ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
75 /* Return the bit flag (lsb set) for our most preferred digest type. */
76 #define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
78 /* Return the bit flag for a given digest algorithm ID. */
79 #define CHAP_MDTYPE_D(digest) \
80 ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
81 ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
82 ((digest) == CHAP_MD5)? MDTYPE_MD5: \
85 /* Can we do the requested digest? */
86 #define CHAP_CANDIGEST(mdtype, digest) \
87 ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
88 ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
89 ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
93 * The code for each digest type has to supply one of these.
95 struct chap_digest_type {
99 * Note: challenge and response arguments below are formatted as
100 * a length byte followed by the actual challenge/response data.
102 void (*generate_challenge)(unsigned char *challenge);
103 int (*verify_response)(int id, char *name,
104 unsigned char *secret, int secret_len,
105 unsigned char *challenge, unsigned char *response,
106 char *message, int message_space);
107 void (*make_response)(unsigned char *response, int id, char *our_name,
108 unsigned char *challenge, char *secret, int secret_len,
109 unsigned char *priv);
110 int (*check_success)(int id, unsigned char *pkt, int len);
111 void (*handle_failure)(unsigned char *pkt, int len);
113 struct chap_digest_type *next;
116 /* Hook for a plugin to validate CHAP challenge */
117 extern int (*chap_verify_hook)(char *name, char *ourname, int id,
118 struct chap_digest_type *digest,
119 unsigned char *challenge, unsigned char *response,
120 char *message, int message_space);
122 /* Called by digest code to register a digest type */
123 extern void chap_register_digest(struct chap_digest_type *);
125 /* Lookup a digest handler by type */
126 extern struct chap_digest_type *chap_find_digest(int digest_code);
128 /* Called by authentication code to start authenticating the peer. */
129 extern void chap_auth_peer(int unit, char *our_name, int digest_code);
131 /* Called by auth. code to start authenticating us to the peer. */
132 extern void chap_auth_with_peer(int unit, char *our_name, int digest_code);
134 /* Represents the CHAP protocol to the main pppd code */
135 extern struct protent chap_protent;