dist/wpa/src/eap_peer/eap_gtc.c

   1 /*
   2  * EAP peer method: EAP-GTC (RFC 3748)
   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 "common.h"
  18 #include "eap_i.h"
  19
  20
  21 struct eap_gtc_data {
  22         int prefix;
  23 };
  24
  25
  26 static void * eap_gtc_init(struct eap_sm *sm)
  27 {
  28         struct eap_gtc_data *data;
  29         data = os_zalloc(sizeof(*data));
  30         if (data == NULL)
  31                 return NULL;
  32
  33         if (sm->m && sm->m->vendor == EAP_VENDOR_IETF &&
  34             sm->m->method == EAP_TYPE_FAST) {
  35                 wpa_printf(MSG_DEBUG, "EAP-GTC: EAP-FAST tunnel - use prefix "
  36                            "with challenge/response");
  37                 data->prefix = 1;
  38         }
  39         return data;
  40 }
  41
  42
  43 static void eap_gtc_deinit(struct eap_sm *sm, void *priv)
  44 {
  45         struct eap_gtc_data *data = priv;
  46         os_free(data);
  47 }
  48
  49
  50 static struct wpabuf * eap_gtc_process(struct eap_sm *sm, void *priv,
  51                                        struct eap_method_ret *ret,
  52                                        const struct wpabuf *reqData)
  53 {
  54         struct eap_gtc_data *data = priv;
  55         struct wpabuf *resp;
  56         const u8 *pos, *password, *identity;
  57         size_t password_len, identity_len, len, plen;
  58         int otp;
  59         u8 id;
  60
  61         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GTC, reqData, &len);
  62         if (pos == NULL) {
  63                 ret->ignore = TRUE;
  64                 return NULL;
  65         }
  66         id = eap_get_id(reqData);
  67
  68         wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-GTC: Request message", pos, len);
  69         if (data->prefix &&
  70             (len < 10 || os_memcmp(pos, "CHALLENGE=", 10) != 0)) {
  71                 wpa_printf(MSG_DEBUG, "EAP-GTC: Challenge did not start with "
  72                            "expected prefix");
  73
  74                 /* Send an empty response in order to allow tunneled
  75                  * acknowledgement of the failure. This will also cover the
  76                  * error case which seems to use EAP-MSCHAPv2 like error
  77                  * reporting with EAP-GTC inside EAP-FAST tunnel. */
  78                 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GTC,
  79                                      0, EAP_CODE_RESPONSE, id);
  80                 return resp;
  81         }
  82
  83         password = eap_get_config_otp(sm, &password_len);
  84         if (password)
  85                 otp = 1;
  86         else {
  87                 password = eap_get_config_password(sm, &password_len);
  88                 otp = 0;
  89         }
  90
  91         if (password == NULL) {
  92                 wpa_printf(MSG_INFO, "EAP-GTC: Password not configured");
  93                 eap_sm_request_otp(sm, (const char *) pos, len);
  94                 ret->ignore = TRUE;
  95                 return NULL;
  96         }
  97
  98         ret->ignore = FALSE;
  99
 100         ret->methodState = data->prefix ? METHOD_MAY_CONT : METHOD_DONE;
 101         ret->decision = DECISION_COND_SUCC;
 102         ret->allowNotifications = FALSE;
 103
 104         plen = password_len;
 105         identity = eap_get_config_identity(sm, &identity_len);
 106         if (identity == NULL)
 107                 return NULL;
 108         if (data->prefix)
 109                 plen += 9 + identity_len + 1;
 110         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GTC, plen,
 111                              EAP_CODE_RESPONSE, id);
 112         if (resp == NULL)
 113                 return NULL;
 114         if (data->prefix) {
 115                 wpabuf_put_data(resp, "RESPONSE=", 9);
 116                 wpabuf_put_data(resp, identity, identity_len);
 117                 wpabuf_put_u8(resp, '\0');
 118         }
 119         wpabuf_put_data(resp, password, password_len);
 120         wpa_hexdump_ascii_key(MSG_MSGDUMP, "EAP-GTC: Response",
 121                               wpabuf_head_u8(resp) + sizeof(struct eap_hdr) +
 122                               1, plen);
 123
 124         if (otp) {
 125                 wpa_printf(MSG_DEBUG, "EAP-GTC: Forgetting used password");
 126                 eap_clear_config_otp(sm);
 127         }
 128
 129         return resp;
 130 }
 131
 132
 133 int eap_peer_gtc_register(void)
 134 {
 135         struct eap_method *eap;
 136         int ret;
 137
 138         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 139                                     EAP_VENDOR_IETF, EAP_TYPE_GTC, "GTC");
 140         if (eap == NULL)
 141                 return -1;
 142
 143         eap->init = eap_gtc_init;
 144         eap->deinit = eap_gtc_deinit;
 145         eap->process = eap_gtc_process;
 146
 147         ret = eap_peer_method_register(eap);
 148         if (ret)
 149                 eap_peer_method_free(eap);
 150         return ret;
 151 }