[457] | 1 | /*
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| 2 | * chap-new.c - New CHAP implementation.
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| 3 | *
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| 4 | * Copyright (c) 2003 Paul Mackerras. All rights reserved.
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| 5 | *
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| 6 | * Redistribution and use in source and binary forms, with or without
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| 7 | * modification, are permitted provided that the following conditions
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| 8 | * are met:
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| 9 | *
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| 10 | * 1. Redistributions of source code must retain the above copyright
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| 11 | * notice, this list of conditions and the following disclaimer.
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| 12 | *
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| 13 | * 2. The name(s) of the authors of this software must not be used to
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| 14 | * endorse or promote products derived from this software without
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| 15 | * prior written permission.
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| 16 | *
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| 17 | * 3. Redistributions of any form whatsoever must retain the following
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| 18 | * acknowledgment:
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| 19 | * "This product includes software developed by Paul Mackerras
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| 20 | * <paulus@samba.org>".
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| 21 | *
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| 22 | * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
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| 23 | * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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| 24 | * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
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| 25 | * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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| 26 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
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| 27 | * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
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| 28 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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| 29 | */
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| 30 |
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| 31 | #include "netif/ppp/ppp_opts.h"
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| 32 | #if PPP_SUPPORT && CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
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| 33 |
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| 34 | #ifndef CHAP_H
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| 35 | #define CHAP_H
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| 36 |
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| 37 | #include "ppp.h"
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| 38 |
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| 39 | #ifdef __cplusplus
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| 40 | extern "C" {
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| 41 | #endif
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| 42 |
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| 43 | /*
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| 44 | * CHAP packets begin with a standard header with code, id, len (2 bytes).
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| 45 | */
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| 46 | #define CHAP_HDRLEN 4
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| 47 |
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| 48 | /*
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| 49 | * Values for the code field.
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| 50 | */
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| 51 | #define CHAP_CHALLENGE 1
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| 52 | #define CHAP_RESPONSE 2
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| 53 | #define CHAP_SUCCESS 3
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| 54 | #define CHAP_FAILURE 4
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| 55 |
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| 56 | /*
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| 57 | * CHAP digest codes.
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| 58 | */
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| 59 | #define CHAP_MD5 5
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| 60 | #if MSCHAP_SUPPORT
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| 61 | #define CHAP_MICROSOFT 0x80
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| 62 | #define CHAP_MICROSOFT_V2 0x81
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| 63 | #endif /* MSCHAP_SUPPORT */
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| 64 |
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| 65 | /*
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| 66 | * Semi-arbitrary limits on challenge and response fields.
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| 67 | */
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| 68 | #define MAX_CHALLENGE_LEN 64
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| 69 | #define MAX_RESPONSE_LEN 64
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| 70 |
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| 71 | /*
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| 72 | * These limits apply to challenge and response packets we send.
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| 73 | * The +4 is the +1 that we actually need rounded up.
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| 74 | */
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| 75 | #define CHAL_MAX_PKTLEN (PPP_HDRLEN + CHAP_HDRLEN + 4 + MAX_CHALLENGE_LEN + MAXNAMELEN)
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| 76 | #define RESP_MAX_PKTLEN (PPP_HDRLEN + CHAP_HDRLEN + 4 + MAX_RESPONSE_LEN + MAXNAMELEN)
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| 77 |
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| 78 | /* bitmask of supported algorithms */
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| 79 | #if MSCHAP_SUPPORT
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| 80 | #define MDTYPE_MICROSOFT_V2 0x1
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| 81 | #define MDTYPE_MICROSOFT 0x2
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| 82 | #endif /* MSCHAP_SUPPORT */
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| 83 | #define MDTYPE_MD5 0x4
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| 84 | #define MDTYPE_NONE 0
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| 85 |
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| 86 | #if MSCHAP_SUPPORT
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| 87 | /* Return the digest alg. ID for the most preferred digest type. */
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| 88 | #define CHAP_DIGEST(mdtype) \
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| 89 | ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
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| 90 | ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
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| 91 | ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
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| 92 | 0
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| 93 | #else /* !MSCHAP_SUPPORT */
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| 94 | #define CHAP_DIGEST(mdtype) \
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| 95 | ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
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| 96 | 0
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| 97 | #endif /* MSCHAP_SUPPORT */
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| 98 |
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| 99 | /* Return the bit flag (lsb set) for our most preferred digest type. */
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| 100 | #define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
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| 101 |
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| 102 | /* Return the bit flag for a given digest algorithm ID. */
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| 103 | #if MSCHAP_SUPPORT
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| 104 | #define CHAP_MDTYPE_D(digest) \
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| 105 | ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
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| 106 | ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
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| 107 | ((digest) == CHAP_MD5)? MDTYPE_MD5: \
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| 108 | 0
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| 109 | #else /* !MSCHAP_SUPPORT */
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| 110 | #define CHAP_MDTYPE_D(digest) \
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| 111 | ((digest) == CHAP_MD5)? MDTYPE_MD5: \
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| 112 | 0
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| 113 | #endif /* MSCHAP_SUPPORT */
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| 114 |
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| 115 | /* Can we do the requested digest? */
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| 116 | #if MSCHAP_SUPPORT
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| 117 | #define CHAP_CANDIGEST(mdtype, digest) \
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| 118 | ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
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| 119 | ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
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| 120 | ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
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| 121 | 0
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| 122 | #else /* !MSCHAP_SUPPORT */
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| 123 | #define CHAP_CANDIGEST(mdtype, digest) \
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| 124 | ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
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| 125 | 0
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| 126 | #endif /* MSCHAP_SUPPORT */
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| 127 |
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| 128 | /*
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| 129 | * The code for each digest type has to supply one of these.
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| 130 | */
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| 131 | struct chap_digest_type {
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| 132 | int code;
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| 133 |
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| 134 | #if PPP_SERVER
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| 135 | /*
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| 136 | * Note: challenge and response arguments below are formatted as
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| 137 | * a length byte followed by the actual challenge/response data.
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| 138 | */
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| 139 | void (*generate_challenge)(ppp_pcb *pcb, unsigned char *challenge);
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| 140 | int (*verify_response)(ppp_pcb *pcb, int id, const char *name,
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| 141 | const unsigned char *secret, int secret_len,
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| 142 | const unsigned char *challenge, const unsigned char *response,
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| 143 | char *message, int message_space);
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| 144 | #endif /* PPP_SERVER */
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| 145 | void (*make_response)(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name,
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| 146 | const unsigned char *challenge, const char *secret, int secret_len,
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| 147 | unsigned char *priv);
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| 148 | int (*check_success)(ppp_pcb *pcb, unsigned char *pkt, int len, unsigned char *priv);
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| 149 | void (*handle_failure)(ppp_pcb *pcb, unsigned char *pkt, int len);
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| 150 | };
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| 151 |
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| 152 | /*
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| 153 | * Each interface is described by chap structure.
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| 154 | */
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| 155 | #if CHAP_SUPPORT
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| 156 | typedef struct chap_client_state {
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| 157 | u8_t flags;
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| 158 | const char *name;
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| 159 | const struct chap_digest_type *digest;
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| 160 | unsigned char priv[64]; /* private area for digest's use */
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| 161 | } chap_client_state;
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| 162 |
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| 163 | #if PPP_SERVER
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| 164 | typedef struct chap_server_state {
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| 165 | u8_t flags;
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| 166 | u8_t id;
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| 167 | const char *name;
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| 168 | const struct chap_digest_type *digest;
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| 169 | int challenge_xmits;
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| 170 | int challenge_pktlen;
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| 171 | unsigned char challenge[CHAL_MAX_PKTLEN];
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| 172 | } chap_server_state;
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| 173 | #endif /* PPP_SERVER */
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| 174 | #endif /* CHAP_SUPPORT */
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| 175 |
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| 176 | #if 0 /* UNUSED */
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| 177 | /* Hook for a plugin to validate CHAP challenge */
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| 178 | extern int (*chap_verify_hook)(char *name, char *ourname, int id,
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| 179 | const struct chap_digest_type *digest,
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| 180 | unsigned char *challenge, unsigned char *response,
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| 181 | char *message, int message_space);
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| 182 | #endif /* UNUSED */
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| 183 |
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| 184 | #if PPP_SERVER
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| 185 | /* Called by authentication code to start authenticating the peer. */
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| 186 | extern void chap_auth_peer(ppp_pcb *pcb, const char *our_name, int digest_code);
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| 187 | #endif /* PPP_SERVER */
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| 188 |
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| 189 | /* Called by auth. code to start authenticating us to the peer. */
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| 190 | extern void chap_auth_with_peer(ppp_pcb *pcb, const char *our_name, int digest_code);
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| 191 |
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| 192 | /* Represents the CHAP protocol to the main pppd code */
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| 193 | extern const struct protent chap_protent;
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| 194 |
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| 195 | #ifdef __cplusplus
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| 196 | }
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| 197 | #endif
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| 198 |
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| 199 | #endif /* CHAP_H */
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| 200 | #endif /* PPP_SUPPORT && CHAP_SUPPORT */
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