aboutsummaryrefslogtreecommitdiffstats
path: root/src/eap_server/eap_server_tls.c
blob: c98fa185bb5dfdaa196f51279674d83b101abe03 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
/*
 * hostapd / EAP-TLS (RFC 2716)
 * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"

#include "common.h"
#include "eap_i.h"
#include "eap_tls_common.h"
#include "crypto/tls.h"


static void eap_tls_reset(struct eap_sm *sm, void *priv);


struct eap_tls_data {
	struct eap_ssl_data ssl;
	enum { START, CONTINUE, SUCCESS, FAILURE } state;
	int established;
};


static const char * eap_tls_state_txt(int state)
{
	switch (state) {
	case START:
		return "START";
	case CONTINUE:
		return "CONTINUE";
	case SUCCESS:
		return "SUCCESS";
	case FAILURE:
		return "FAILURE";
	default:
		return "Unknown?!";
	}
}


static void eap_tls_state(struct eap_tls_data *data, int state)
{
	wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
		   eap_tls_state_txt(data->state),
		   eap_tls_state_txt(state));
	data->state = state;
}


static void * eap_tls_init(struct eap_sm *sm)
{
	struct eap_tls_data *data;

	data = os_zalloc(sizeof(*data));
	if (data == NULL)
		return NULL;
	data->state = START;

	if (eap_server_tls_ssl_init(sm, &data->ssl, 1)) {
		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
		eap_tls_reset(sm, data);
		return NULL;
	}

	return data;
}


static void eap_tls_reset(struct eap_sm *sm, void *priv)
{
	struct eap_tls_data *data = priv;
	if (data == NULL)
		return;
	eap_server_tls_ssl_deinit(sm, &data->ssl);
	os_free(data);
}


static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
					   struct eap_tls_data *data, u8 id)
{
	struct wpabuf *req;

	req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TLS, 1, EAP_CODE_REQUEST,
			    id);
	if (req == NULL) {
		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
			   "request");
		eap_tls_state(data, FAILURE);
		return NULL;
	}

	wpabuf_put_u8(req, EAP_TLS_FLAGS_START);

	eap_tls_state(data, CONTINUE);

	return req;
}


static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
{
	struct eap_tls_data *data = priv;
	struct wpabuf *res;

	if (data->ssl.state == FRAG_ACK) {
		return eap_server_tls_build_ack(id, EAP_TYPE_TLS, 0);
	}

	if (data->ssl.state == WAIT_FRAG_ACK) {
		res = eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TLS, 0,
					       id);
		goto check_established;
	}

	switch (data->state) {
	case START:
		return eap_tls_build_start(sm, data, id);
	case CONTINUE:
		if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
			data->established = 1;
		break;
	default:
		wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
			   __func__, data->state);
		return NULL;
	}

	res = eap_server_tls_build_msg(&data->ssl, EAP_TYPE_TLS, 0, id);

check_established:
	if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
		/* TLS handshake has been completed and there are no more
		 * fragments waiting to be sent out. */
		wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
		eap_tls_state(data, SUCCESS);
	}

	return res;
}


static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
			     struct wpabuf *respData)
{
	const u8 *pos;
	size_t len;

	pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TLS, respData, &len);
	if (pos == NULL || len < 1) {
		wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
		return TRUE;
	}

	return FALSE;
}


static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
				const struct wpabuf *respData)
{
	struct eap_tls_data *data = priv;
	if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
		wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
			   "handshake message");
		return;
	}
	if (eap_server_tls_phase1(sm, &data->ssl) < 0)
		eap_tls_state(data, FAILURE);
}


static void eap_tls_process(struct eap_sm *sm, void *priv,
			    struct wpabuf *respData)
{
	struct eap_tls_data *data = priv;
	if (eap_server_tls_process(sm, &data->ssl, respData, data,
				   EAP_TYPE_TLS, NULL, eap_tls_process_msg) <
	    0)
		eap_tls_state(data, FAILURE);
}


static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
{
	struct eap_tls_data *data = priv;
	return data->state == SUCCESS || data->state == FAILURE;
}


static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_tls_data *data = priv;
	u8 *eapKeyData;

	if (data->state != SUCCESS)
		return NULL;

	eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
					       "client EAP encryption",
					       EAP_TLS_KEY_LEN);
	if (eapKeyData) {
		*len = EAP_TLS_KEY_LEN;
		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
			    eapKeyData, EAP_TLS_KEY_LEN);
	} else {
		wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
	}

	return eapKeyData;
}


static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
{
	struct eap_tls_data *data = priv;
	u8 *eapKeyData, *emsk;

	if (data->state != SUCCESS)
		return NULL;

	eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
					       "client EAP encryption",
					       EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
	if (eapKeyData) {
		emsk = os_malloc(EAP_EMSK_LEN);
		if (emsk)
			os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
				  EAP_EMSK_LEN);
		os_free(eapKeyData);
	} else
		emsk = NULL;

	if (emsk) {
		*len = EAP_EMSK_LEN;
		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
			    emsk, EAP_EMSK_LEN);
	} else {
		wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
	}

	return emsk;
}


static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
{
	struct eap_tls_data *data = priv;
	return data->state == SUCCESS;
}


int eap_server_tls_register(void)
{
	struct eap_method *eap;
	int ret;

	eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
				      EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
	if (eap == NULL)
		return -1;

	eap->init = eap_tls_init;
	eap->reset = eap_tls_reset;
	eap->buildReq = eap_tls_buildReq;
	eap->check = eap_tls_check;
	eap->process = eap_tls_process;
	eap->isDone = eap_tls_isDone;
	eap->getKey = eap_tls_getKey;
	eap->isSuccess = eap_tls_isSuccess;
	eap->get_emsk = eap_tls_get_emsk;

	ret = eap_server_method_register(eap);
	if (ret)
		eap_server_method_free(eap);
	return ret;
}