contrib/hostapd-0.5.8/eap_md5.c

   1 /*
   2  * hostapd / EAP-MD5 server
   3  * Copyright (c) 2004-2006, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "hostapd.h"
  18 #include "common.h"
  19 #include "eap_i.h"
  20 #include "md5.h"
  21 #include "crypto.h"
  22
  23
  24 #define CHALLENGE_LEN 16
  25
  26 struct eap_md5_data {
  27         u8 challenge[CHALLENGE_LEN];
  28         enum { CONTINUE, SUCCESS, FAILURE } state;
  29 };
  30
  31
  32 static void * eap_md5_init(struct eap_sm *sm)
  33 {
  34         struct eap_md5_data *data;
  35
  36         data = wpa_zalloc(sizeof(*data));
  37         if (data == NULL)
  38                 return NULL;
  39         data->state = CONTINUE;
  40
  41         return data;
  42 }
  43
  44
  45 static void eap_md5_reset(struct eap_sm *sm, void *priv)
  46 {
  47         struct eap_md5_data *data = priv;
  48         free(data);
  49 }
  50
  51
  52 static u8 * eap_md5_buildReq(struct eap_sm *sm, void *priv, int id,
  53                              size_t *reqDataLen)
  54 {
  55         struct eap_md5_data *data = priv;
  56         struct eap_hdr *req;
  57         u8 *pos;
  58
  59         if (hostapd_get_rand(data->challenge, CHALLENGE_LEN)) {
  60                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to get random data");
  61                 data->state = FAILURE;
  62                 return NULL;
  63         }
  64
  65         req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, reqDataLen,
  66                             1 + CHALLENGE_LEN, EAP_CODE_REQUEST, id, &pos);
  67         if (req == NULL) {
  68                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to allocate memory for "
  69                            "request");
  70                 data->state = FAILURE;
  71                 return NULL;
  72         }
  73
  74         *pos++ = CHALLENGE_LEN;
  75         memcpy(pos, data->challenge, CHALLENGE_LEN);
  76         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge", pos, CHALLENGE_LEN);
  77
  78         data->state = CONTINUE;
  79
  80         return (u8 *) req;
  81 }
  82
  83
  84 static Boolean eap_md5_check(struct eap_sm *sm, void *priv,
  85                              u8 *respData, size_t respDataLen)
  86 {
  87         const u8 *pos;
  88         size_t len;
  89
  90         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5,
  91                                respData, respDataLen, &len);
  92         if (pos == NULL || len < 1) {
  93                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame");
  94                 return TRUE;
  95         }
  96         if (*pos != MD5_MAC_LEN || 1 + MD5_MAC_LEN > len) {
  97                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid response "
  98                            "(response_len=%d payload_len=%lu",
  99                            *pos, (unsigned long) len);
 100                 return TRUE;
 101         }
 102
 103         return FALSE;
 104 }
 105
 106
 107 static void eap_md5_process(struct eap_sm *sm, void *priv,
 108                             u8 *respData, size_t respDataLen)
 109 {
 110         struct eap_md5_data *data = priv;
 111         struct eap_hdr *resp;
 112         const u8 *pos;
 113         const u8 *addr[3];
 114         size_t len[3], plen;
 115         u8 hash[MD5_MAC_LEN];
 116
 117         if (sm->user == NULL || sm->user->password == NULL ||
 118             sm->user->password_hash) {
 119                 wpa_printf(MSG_INFO, "EAP-MD5: Plaintext password not "
 120                            "configured");
 121                 data->state = FAILURE;
 122                 return;
 123         }
 124
 125         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5,
 126                                respData, respDataLen, &plen);
 127         if (pos == NULL || *pos != MD5_MAC_LEN || plen < 1 + MD5_MAC_LEN)
 128                 return; /* Should not happen - frame already validated */
 129
 130         pos++; /* Skip response len */
 131         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", pos, MD5_MAC_LEN);
 132
 133         resp = (struct eap_hdr *) respData;
 134         addr[0] = &resp->identifier;
 135         len[0] = 1;
 136         addr[1] = sm->user->password;
 137         len[1] = sm->user->password_len;
 138         addr[2] = data->challenge;
 139         len[2] = CHALLENGE_LEN;
 140         md5_vector(3, addr, len, hash);
 141
 142         if (memcmp(hash, pos, MD5_MAC_LEN) == 0) {
 143                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Success");
 144                 data->state = SUCCESS;
 145         } else {
 146                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Failure");
 147                 data->state = FAILURE;
 148         }
 149 }
 150
 151
 152 static Boolean eap_md5_isDone(struct eap_sm *sm, void *priv)
 153 {
 154         struct eap_md5_data *data = priv;
 155         return data->state != CONTINUE;
 156 }
 157
 158
 159 static Boolean eap_md5_isSuccess(struct eap_sm *sm, void *priv)
 160 {
 161         struct eap_md5_data *data = priv;
 162         return data->state == SUCCESS;
 163 }
 164
 165
 166 int eap_server_md5_register(void)
 167 {
 168         struct eap_method *eap;
 169         int ret;
 170
 171         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 172                                       EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 173         if (eap == NULL)
 174                 return -1;
 175
 176         eap->init = eap_md5_init;
 177         eap->reset = eap_md5_reset;
 178         eap->buildReq = eap_md5_buildReq;
 179         eap->check = eap_md5_check;
 180         eap->process = eap_md5_process;
 181         eap->isDone = eap_md5_isDone;
 182         eap->isSuccess = eap_md5_isSuccess;
 183
 184         ret = eap_server_method_register(eap);
 185         if (ret)
 186                 eap_server_method_free(eap);
 187         return ret;
 188 }