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
eap_gtc_init(struct eap_sm * sm)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
eap_gtc_deinit(struct eap_sm * sm,void * priv)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
eap_gtc_process(struct eap_sm * sm,void * priv,struct eap_method_ret * ret,const struct wpabuf * reqData)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
eap_peer_gtc_register(void)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 }
152