src/eap_server/eap_server_md5.c

   1 /*
   2  * hostapd / EAP-MD5 server
   3  * Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi>
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "includes.h"
  10
  11 #include "common.h"
  12 #include "crypto/random.h"
  13 #include "eap_i.h"
  14 #include "eap_common/chap.h"
  15
  16
  17 #define CHALLENGE_LEN 16
  18
  19 struct eap_md5_data {
  20         u8 challenge[CHALLENGE_LEN];
  21         enum { CONTINUE, SUCCESS, FAILURE } state;
  22 };
  23
  24
  25 static void * eap_md5_init(struct eap_sm *sm)
  26 {
  27         struct eap_md5_data *data;
  28
  29         data = os_zalloc(sizeof(*data));
  30         if (data == NULL)
  31                 return NULL;
  32         data->state = CONTINUE;
  33
  34         return data;
  35 }
  36
  37
  38 static void eap_md5_reset(struct eap_sm *sm, void *priv)
  39 {
  40         struct eap_md5_data *data = priv;
  41         os_free(data);
  42 }
  43
  44
  45 static struct wpabuf * eap_md5_buildReq(struct eap_sm *sm, void *priv, u8 id)
  46 {
  47         struct eap_md5_data *data = priv;
  48         struct wpabuf *req;
  49
  50         if (random_get_bytes(data->challenge, CHALLENGE_LEN)) {
  51                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to get random data");
  52                 data->state = FAILURE;
  53                 return NULL;
  54         }
  55
  56         req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHALLENGE_LEN,
  57                             EAP_CODE_REQUEST, id);
  58         if (req == NULL) {
  59                 wpa_printf(MSG_ERROR, "EAP-MD5: Failed to allocate memory for "
  60                            "request");
  61                 data->state = FAILURE;
  62                 return NULL;
  63         }
  64
  65         wpabuf_put_u8(req, CHALLENGE_LEN);
  66         wpabuf_put_data(req, data->challenge, CHALLENGE_LEN);
  67         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge", data->challenge,
  68                     CHALLENGE_LEN);
  69
  70         data->state = CONTINUE;
  71
  72         return req;
  73 }
  74
  75
  76 static Boolean eap_md5_check(struct eap_sm *sm, void *priv,
  77                              struct wpabuf *respData)
  78 {
  79         const u8 *pos;
  80         size_t len;
  81
  82         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &len);
  83         if (pos == NULL || len < 1) {
  84                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame");
  85                 return TRUE;
  86         }
  87         if (*pos != CHAP_MD5_LEN || 1 + CHAP_MD5_LEN > len) {
  88                 wpa_printf(MSG_INFO, "EAP-MD5: Invalid response "
  89                            "(response_len=%d payload_len=%lu",
  90                            *pos, (unsigned long) len);
  91                 return TRUE;
  92         }
  93
  94         return FALSE;
  95 }
  96
  97
  98 static void eap_md5_process(struct eap_sm *sm, void *priv,
  99                             struct wpabuf *respData)
 100 {
 101         struct eap_md5_data *data = priv;
 102         const u8 *pos;
 103         size_t plen;
 104         u8 hash[CHAP_MD5_LEN], id;
 105
 106         if (sm->user == NULL || sm->user->password == NULL ||
 107             sm->user->password_hash) {
 108                 wpa_printf(MSG_INFO, "EAP-MD5: Plaintext password not "
 109                            "configured");
 110                 data->state = FAILURE;
 111                 return;
 112         }
 113
 114         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, respData, &plen);
 115         if (pos == NULL || *pos != CHAP_MD5_LEN || plen < 1 + CHAP_MD5_LEN)
 116                 return; /* Should not happen - frame already validated */
 117
 118         pos++; /* Skip response len */
 119         wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", pos, CHAP_MD5_LEN);
 120
 121         id = eap_get_id(respData);
 122         if (chap_md5(id, sm->user->password, sm->user->password_len,
 123                      data->challenge, CHALLENGE_LEN, hash)) {
 124                 wpa_printf(MSG_INFO, "EAP-MD5: CHAP MD5 operation failed");
 125                 data->state = FAILURE;
 126                 return;
 127         }
 128
 129         if (os_memcmp_const(hash, pos, CHAP_MD5_LEN) == 0) {
 130                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Success");
 131                 data->state = SUCCESS;
 132         } else {
 133                 wpa_printf(MSG_DEBUG, "EAP-MD5: Done - Failure");
 134                 data->state = FAILURE;
 135         }
 136 }
 137
 138
 139 static Boolean eap_md5_isDone(struct eap_sm *sm, void *priv)
 140 {
 141         struct eap_md5_data *data = priv;
 142         return data->state != CONTINUE;
 143 }
 144
 145
 146 static Boolean eap_md5_isSuccess(struct eap_sm *sm, void *priv)
 147 {
 148         struct eap_md5_data *data = priv;
 149         return data->state == SUCCESS;
 150 }
 151
 152
 153 int eap_server_md5_register(void)
 154 {
 155         struct eap_method *eap;
 156
 157         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 158                                       EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
 159         if (eap == NULL)
 160                 return -1;
 161
 162         eap->init = eap_md5_init;
 163         eap->reset = eap_md5_reset;
 164         eap->buildReq = eap_md5_buildReq;
 165         eap->check = eap_md5_check;
 166         eap->process = eap_md5_process;
 167         eap->isDone = eap_md5_isDone;
 168         eap->isSuccess = eap_md5_isSuccess;
 169
 170         return eap_server_method_register(eap);
 171 }