pppd/chap-new.h

   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_MICROSOFT        0x2
  60 #define MDTYPE_MD5              0x4
  61 #define MDTYPE_NONE             0
  62
  63 /* hashes supported by this instance of pppd */
  64 extern 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_MD5)? CHAP_MD5: \
  69     ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
  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  */
  93 struct 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                 unsigned char *priv);
 108         int (*check_success)(unsigned char *pkt, int len, unsigned char *priv);
 109         void (*handle_failure)(unsigned char *pkt, int len);
 110
 111         struct chap_digest_type *next;
 112 };
 113
 114 /* Hook for a plugin to validate CHAP challenge */
 115 extern int (*chap_verify_hook)(char *name, char *ourname, int id,
 116                         struct chap_digest_type *digest,
 117                         unsigned char *challenge, unsigned char *response,
 118                         char *message, int message_space);
 119
 120 /* Called by digest code to register a digest type */
 121 extern void chap_register_digest(struct chap_digest_type *);
 122
 123 /* Called by authentication code to start authenticating the peer. */
 124 extern void chap_auth_peer(int unit, char *our_name, int digest_code);
 125
 126 /* Called by auth. code to start authenticating us to the peer. */
 127 extern void chap_auth_with_peer(int unit, char *our_name, int digest_code);
 128
 129 /* Represents the CHAP protocol to the main pppd code */
 130 extern struct protent chap_protent;