src/eap_server/eap_md5.c

   1 /*
   2  * hostapd / EAP-MD5 server
   3  * Copyright (c) 2004-2007, 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 "common.h"
  18 #include "eap_i.h"
  19 #include "eap_common/chap.h"
  20
  21
  22 #define CHALLENGE_LEN 16
  23
  24 struct eap_md5_data {
  25         u8 challenge[CHALLENGE_LEN];
  26         enum { CONTINUE, SUCCESS, FAILURE } state;
  27 };
  28
  29
  30 static void * eap_md5_init(struct eap_sm *sm)
  31 {
  32         struct eap_md5_data *data;
  33
  34         data = os_zalloc(sizeof(*data));
  35         if (data == NULL)
  36                 return NULL;
  37         data->state = CONTINUE;
  38
  39         return data;
  40 }
  41
  42
  43 static void eap_md5_reset(struct eap_sm *sm, void *priv)
  44 {
  45         struct eap_md5_data *data = priv;
  46         os_free(data);
  47 }
  48
  49
  50 static struct wpabuf * eap_md5_buildReq(struct eap_sm *sm, void *priv, u8 id)
  51 {
  52         struct eap_md5_data *data = priv;
  53         struct wpabuf *req;
  54
  55         if (os_get_random(data->challenge, CHALLENGE_LEN)) {
  56                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to get random data");
  57                 data->state = FAILURE;
  58                 return NULL;
  59         }
  60
  61         req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHALLENGE_LEN,
  62                             EAP_CODE_REQUEST, id);
  63         if (req == NULL) {
  64                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to allocate memory for "
  65                            "request");
  66                 data->state = FAILURE;
  67                 return NULL;
  68         }
  69
  70         wpabuf_put_u8(req, CHALLENGE_LEN);
  71         wpabuf_put_data(req, data->challenge, CHALLENGE_LEN);
  72         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge", data->challenge,
  73                     CHALLENGE_LEN);
  74
  75         data->state = CONTINUE;
  76
  77         return req;
  78 }
  79
  80
  81 static Boolean eap_md5_check(struct eap_sm *sm, void *priv,
  82                              struct wpabuf *respData)
  83 {
  84         const u8 *pos;
  85         size_t len;
  86
  87         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &len);
  88         if (pos == NULL || len < 1) {
  89                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame");
  90                 return TRUE;
  91         }
  92         if (*pos != CHAP_MD5_LEN || 1 + CHAP_MD5_LEN > len) {
  93                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid response "
  94                            "(response_len=%d payload_len=%lu",
  95                            *pos, (unsigned long) len);
  96                 return TRUE;
  97         }
  98
  99         return FALSE;
 100 }
 101
 102
 103 static void eap_md5_process(struct eap_sm *sm, void *priv,
 104                             struct wpabuf *respData)
 105 {
 106         struct eap_md5_data *data = priv;
 107         const u8 *pos;
 108         size_t plen;
 109         u8 hash[CHAP_MD5_LEN], id;
 110
 111         if (sm->user == NULL || sm->user->password == NULL ||
 112             sm->user->password_hash) {
 113                 wpa_printf(MSG_INFO, "EAP-MD5: Plaintext password not "
 114                            "configured");
 115                 data->state = FAILURE;
 116                 return;
 117         }
 118
 119         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &plen);
 120         if (pos == NULL || *pos != CHAP_MD5_LEN || plen < 1 + CHAP_MD5_LEN)
 121                 return; /* Should not happen - frame already validated */
 122
 123         pos++; /* Skip response len */
 124         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", pos, CHAP_MD5_LEN);
 125
 126         id = eap_get_id(respData);
 127         chap_md5(id, sm->user->password, sm->user->password_len,
 128                  data->challenge, CHALLENGE_LEN, hash);
 129
 130         if (os_memcmp(hash, pos, CHAP_MD5_LEN) == 0) {
 131                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Success");
 132                 data->state = SUCCESS;
 133         } else {
 134                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Failure");
 135                 data->state = FAILURE;
 136         }
 137 }
 138
 139
 140 static Boolean eap_md5_isDone(struct eap_sm *sm, void *priv)
 141 {
 142         struct eap_md5_data *data = priv;
 143         return data->state != CONTINUE;
 144 }
 145
 146
 147 static Boolean eap_md5_isSuccess(struct eap_sm *sm, void *priv)
 148 {
 149         struct eap_md5_data *data = priv;
 150         return data->state == SUCCESS;
 151 }
 152
 153
 154 int eap_server_md5_register(void)
 155 {
 156         struct eap_method *eap;
 157         int ret;
 158
 159         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 160                                       EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 161         if (eap == NULL)
 162                 return -1;
 163
 164         eap->init = eap_md5_init;
 165         eap->reset = eap_md5_reset;
 166         eap->buildReq = eap_md5_buildReq;
 167         eap->check = eap_md5_check;
 168         eap->process = eap_md5_process;
 169         eap->isDone = eap_md5_isDone;
 170         eap->isSuccess = eap_md5_isSuccess;
 171
 172         ret = eap_server_method_register(eap);
 173         if (ret)
 174                 eap_server_method_free(eap);
 175         return ret;
 176 }