contrib/hostapd/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 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 "eap_i.h"
  13
  14
  15 struct eap_gtc_data {
  16         int prefix;
  17 };
  18
  19
  20 static void * eap_gtc_init(struct eap_sm *sm)
  21 {
  22         struct eap_gtc_data *data;
  23         data = os_zalloc(sizeof(*data));
  24         if (data == NULL)
  25                 return NULL;
  26
  27         if (sm->m && sm->m->vendor == EAP_VENDOR_IETF &&
  28             sm->m->method == EAP_TYPE_FAST) {
  29                 wpa_printf(MSG_DEBUG, "EAP-GTC: EAP-FAST tunnel - use prefix "
  30                            "with challenge/response");
  31                 data->prefix = 1;
  32         }
  33         return data;
  34 }
  35
  36
  37 static void eap_gtc_deinit(struct eap_sm *sm, void *priv)
  38 {
  39         struct eap_gtc_data *data = priv;
  40         os_free(data);
  41 }
  42
  43
  44 static struct wpabuf * eap_gtc_process(struct eap_sm *sm, void *priv,
  45                                        struct eap_method_ret *ret,
  46                                        const struct wpabuf *reqData)
  47 {
  48         struct eap_gtc_data *data = priv;
  49         struct wpabuf *resp;
  50         const u8 *pos, *password, *identity;
  51         size_t password_len, identity_len, len, plen;
  52         int otp;
  53         u8 id;
  54
  55         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_GTC, reqData, &len);
  56         if (pos == NULL) {
  57                 ret->ignore = TRUE;
  58                 return NULL;
  59         }
  60         id = eap_get_id(reqData);
  61
  62         wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-GTC: Request message", pos, len);
  63         if (data->prefix &&
  64             (len < 10 || os_memcmp(pos, "CHALLENGE=", 10) != 0)) {
  65                 wpa_printf(MSG_DEBUG, "EAP-GTC: Challenge did not start with "
  66                            "expected prefix");
  67
  68                 /* Send an empty response in order to allow tunneled
  69                  * acknowledgement of the failure. This will also cover the
  70                  * error case which seems to use EAP-MSCHAPv2 like error
  71                  * reporting with EAP-GTC inside EAP-FAST tunnel. */
  72                 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GTC,
  73                                      0, EAP_CODE_RESPONSE, id);
  74                 return resp;
  75         }
  76
  77         password = eap_get_config_otp(sm, &password_len);
  78         if (password)
  79                 otp = 1;
  80         else {
  81                 password = eap_get_config_password(sm, &password_len);
  82                 otp = 0;
  83         }
  84
  85         if (password == NULL) {
  86                 wpa_printf(MSG_INFO, "EAP-GTC: Password not configured");
  87                 eap_sm_request_otp(sm, (const char *) pos, len);
  88                 ret->ignore = TRUE;
  89                 return NULL;
  90         }
  91
  92         ret->ignore = FALSE;
  93
  94         ret->methodState = data->prefix ? METHOD_MAY_CONT : METHOD_DONE;
  95         ret->decision = DECISION_COND_SUCC;
  96         ret->allowNotifications = FALSE;
  97
  98         plen = password_len;
  99         identity = eap_get_config_identity(sm, &identity_len);
 100         if (identity == NULL)
 101                 return NULL;
 102         if (data->prefix)
 103                 plen += 9 + identity_len + 1;
 104         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_GTC, plen,
 105                              EAP_CODE_RESPONSE, id);
 106         if (resp == NULL)
 107                 return NULL;
 108         if (data->prefix) {
 109                 wpabuf_put_data(resp, "RESPONSE=", 9);
 110                 wpabuf_put_data(resp, identity, identity_len);
 111                 wpabuf_put_u8(resp, '\0');
 112         }
 113         wpabuf_put_data(resp, password, password_len);
 114         wpa_hexdump_ascii_key(MSG_MSGDUMP, "EAP-GTC: Response",
 115                               wpabuf_head_u8(resp) + sizeof(struct eap_hdr) +
 116                               1, plen);
 117
 118         if (otp) {
 119                 wpa_printf(MSG_DEBUG, "EAP-GTC: Forgetting used password");
 120                 eap_clear_config_otp(sm);
 121         }
 122
 123         return resp;
 124 }
 125
 126
 127 int eap_peer_gtc_register(void)
 128 {
 129         struct eap_method *eap;
 130         int ret;
 131
 132         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 133                                     EAP_VENDOR_IETF, EAP_TYPE_GTC, "GTC");
 134         if (eap == NULL)
 135                 return -1;
 136
 137         eap->init = eap_gtc_init;
 138         eap->deinit = eap_gtc_deinit;
 139         eap->process = eap_gtc_process;
 140
 141         ret = eap_peer_method_register(eap);
 142         if (ret)
 143                 eap_peer_method_free(eap);
 144         return ret;
 145 }