Disconnect hostapd from building in base
[dragonfly.git] / contrib / hostapd / src / eap_server / eap_server_tls_common.c
CommitLineData
a875087d 1/*
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2 * EAP-TLS/PEAP/TTLS/FAST server common functions
3 * Copyright (c) 2004-2009, Jouni Malinen <j@w1.fi>
a875087d 4 *
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5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
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7 */
8
9#include "includes.h"
10
11#include "common.h"
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12#include "crypto/sha1.h"
13#include "crypto/tls.h"
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14#include "eap_i.h"
15#include "eap_tls_common.h"
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16
17
18static void eap_server_tls_free_in_buf(struct eap_ssl_data *data);
19
20
21struct wpabuf * eap_tls_msg_alloc(EapType type, size_t payload_len,
22 u8 code, u8 identifier)
23{
24 if (type == EAP_UNAUTH_TLS_TYPE)
25 return eap_msg_alloc(EAP_VENDOR_UNAUTH_TLS,
26 EAP_VENDOR_TYPE_UNAUTH_TLS, payload_len,
27 code, identifier);
28 return eap_msg_alloc(EAP_VENDOR_IETF, type, payload_len, code,
29 identifier);
30}
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31
32
33int eap_server_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
34 int verify_peer)
35{
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36 if (sm->ssl_ctx == NULL) {
37 wpa_printf(MSG_ERROR, "TLS context not initialized - cannot use TLS-based EAP method");
38 return -1;
39 }
40
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41 data->eap = sm;
42 data->phase2 = sm->init_phase2;
43
44 data->conn = tls_connection_init(sm->ssl_ctx);
45 if (data->conn == NULL) {
46 wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
47 "connection");
48 return -1;
49 }
50
51 if (tls_connection_set_verify(sm->ssl_ctx, data->conn, verify_peer)) {
52 wpa_printf(MSG_INFO, "SSL: Failed to configure verification "
53 "of TLS peer certificate");
54 tls_connection_deinit(sm->ssl_ctx, data->conn);
55 data->conn = NULL;
56 return -1;
57 }
58
4781064b 59 data->tls_out_limit = sm->fragment_size > 0 ? sm->fragment_size : 1398;
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60 if (data->phase2) {
61 /* Limit the fragment size in the inner TLS authentication
62 * since the outer authentication with EAP-PEAP does not yet
63 * support fragmentation */
64 if (data->tls_out_limit > 100)
65 data->tls_out_limit -= 100;
66 }
67 return 0;
68}
69
70
71void eap_server_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
72{
73 tls_connection_deinit(sm->ssl_ctx, data->conn);
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74 eap_server_tls_free_in_buf(data);
75 wpabuf_free(data->tls_out);
76 data->tls_out = NULL;
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77}
78
79
80u8 * eap_server_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
81 char *label, size_t len)
82{
83 struct tls_keys keys;
84 u8 *rnd = NULL, *out;
85
86 out = os_malloc(len);
87 if (out == NULL)
88 return NULL;
89
90 if (tls_connection_prf(sm->ssl_ctx, data->conn, label, 0, out, len) ==
91 0)
92 return out;
93
94 if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
95 goto fail;
96
97 if (keys.client_random == NULL || keys.server_random == NULL ||
98 keys.master_key == NULL)
99 goto fail;
100
101 rnd = os_malloc(keys.client_random_len + keys.server_random_len);
102 if (rnd == NULL)
103 goto fail;
104 os_memcpy(rnd, keys.client_random, keys.client_random_len);
105 os_memcpy(rnd + keys.client_random_len, keys.server_random,
106 keys.server_random_len);
107
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108 if (tls_prf_sha1_md5(keys.master_key, keys.master_key_len,
109 label, rnd, keys.client_random_len +
110 keys.server_random_len, out, len))
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111 goto fail;
112
113 os_free(rnd);
114 return out;
115
116fail:
117 os_free(out);
118 os_free(rnd);
119 return NULL;
120}
121
122
123struct wpabuf * eap_server_tls_build_msg(struct eap_ssl_data *data,
124 int eap_type, int version, u8 id)
125{
126 struct wpabuf *req;
127 u8 flags;
128 size_t send_len, plen;
129
130 wpa_printf(MSG_DEBUG, "SSL: Generating Request");
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131 if (data->tls_out == NULL) {
132 wpa_printf(MSG_ERROR, "SSL: tls_out NULL in %s", __func__);
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133 return NULL;
134 }
135
136 flags = version;
4781064b 137 send_len = wpabuf_len(data->tls_out) - data->tls_out_pos;
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138 if (1 + send_len > data->tls_out_limit) {
139 send_len = data->tls_out_limit - 1;
140 flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
4781064b 141 if (data->tls_out_pos == 0) {
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142 flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
143 send_len -= 4;
144 }
145 }
146
147 plen = 1 + send_len;
148 if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)
149 plen += 4;
150
4781064b 151 req = eap_tls_msg_alloc(eap_type, plen, EAP_CODE_REQUEST, id);
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152 if (req == NULL)
153 return NULL;
154
155 wpabuf_put_u8(req, flags); /* Flags */
156 if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)
4781064b 157 wpabuf_put_be32(req, wpabuf_len(data->tls_out));
a875087d 158
4781064b 159 wpabuf_put_data(req, wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
a875087d 160 send_len);
4781064b 161 data->tls_out_pos += send_len;
a875087d 162
4781064b 163 if (data->tls_out_pos == wpabuf_len(data->tls_out)) {
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164 wpa_printf(MSG_DEBUG, "SSL: Sending out %lu bytes "
165 "(message sent completely)",
166 (unsigned long) send_len);
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167 wpabuf_free(data->tls_out);
168 data->tls_out = NULL;
169 data->tls_out_pos = 0;
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170 data->state = MSG;
171 } else {
172 wpa_printf(MSG_DEBUG, "SSL: Sending out %lu bytes "
173 "(%lu more to send)", (unsigned long) send_len,
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174 (unsigned long) wpabuf_len(data->tls_out) -
175 data->tls_out_pos);
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176 data->state = WAIT_FRAG_ACK;
177 }
178
179 return req;
180}
181
182
183struct wpabuf * eap_server_tls_build_ack(u8 id, int eap_type, int version)
184{
185 struct wpabuf *req;
186
4781064b 187 req = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_REQUEST, id);
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188 if (req == NULL)
189 return NULL;
190 wpa_printf(MSG_DEBUG, "SSL: Building ACK");
191 wpabuf_put_u8(req, version); /* Flags */
192 return req;
193}
194
195
196static int eap_server_tls_process_cont(struct eap_ssl_data *data,
197 const u8 *buf, size_t len)
198{
199 /* Process continuation of a pending message */
4781064b 200 if (len > wpabuf_tailroom(data->tls_in)) {
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201 wpa_printf(MSG_DEBUG, "SSL: Fragment overflow");
202 return -1;
203 }
204
4781064b 205 wpabuf_put_data(data->tls_in, buf, len);
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206 wpa_printf(MSG_DEBUG, "SSL: Received %lu bytes, waiting for %lu "
207 "bytes more", (unsigned long) len,
4781064b 208 (unsigned long) wpabuf_tailroom(data->tls_in));
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209
210 return 0;
211}
212
213
214static int eap_server_tls_process_fragment(struct eap_ssl_data *data,
215 u8 flags, u32 message_length,
216 const u8 *buf, size_t len)
217{
218 /* Process a fragment that is not the last one of the message */
4781064b 219 if (data->tls_in == NULL && !(flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)) {
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220 wpa_printf(MSG_DEBUG, "SSL: No Message Length field in a "
221 "fragmented packet");
222 return -1;
223 }
224
4781064b 225 if (data->tls_in == NULL) {
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226 /* First fragment of the message */
227
228 /* Limit length to avoid rogue peers from causing large
229 * memory allocations. */
230 if (message_length > 65536) {
231 wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size"
232 " over 64 kB)");
233 return -1;
234 }
235
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236 if (len > message_length) {
237 wpa_printf(MSG_INFO, "SSL: Too much data (%d bytes) in "
238 "first fragment of frame (TLS Message "
239 "Length %d bytes)",
240 (int) len, (int) message_length);
241 return -1;
242 }
243
244 data->tls_in = wpabuf_alloc(message_length);
245 if (data->tls_in == NULL) {
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246 wpa_printf(MSG_DEBUG, "SSL: No memory for message");
247 return -1;
248 }
4781064b 249 wpabuf_put_data(data->tls_in, buf, len);
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250 wpa_printf(MSG_DEBUG, "SSL: Received %lu bytes in first "
251 "fragment, waiting for %lu bytes more",
252 (unsigned long) len,
4781064b 253 (unsigned long) wpabuf_tailroom(data->tls_in));
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254 }
255
256 return 0;
257}
258
259
260int eap_server_tls_phase1(struct eap_sm *sm, struct eap_ssl_data *data)
261{
4781064b 262 if (data->tls_out) {
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263 /* This should not happen.. */
264 wpa_printf(MSG_INFO, "SSL: pending tls_out data when "
265 "processing new message");
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266 wpabuf_free(data->tls_out);
267 WPA_ASSERT(data->tls_out == NULL);
268 }
269
270 data->tls_out = tls_connection_server_handshake(sm->ssl_ctx,
271 data->conn,
272 data->tls_in, NULL);
273 if (data->tls_out == NULL) {
274 wpa_printf(MSG_INFO, "SSL: TLS processing failed");
275 return -1;
a875087d 276 }
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277 if (tls_connection_get_failed(sm->ssl_ctx, data->conn)) {
278 /* TLS processing has failed - return error */
279 wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
280 "report error");
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281 return -1;
282 }
4781064b 283
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284 return 0;
285}
286
287
288static int eap_server_tls_reassemble(struct eap_ssl_data *data, u8 flags,
289 const u8 **pos, size_t *left)
290{
291 unsigned int tls_msg_len = 0;
292 const u8 *end = *pos + *left;
293
294 if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
295 if (*left < 4) {
296 wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
297 "length");
298 return -1;
299 }
300 tls_msg_len = WPA_GET_BE32(*pos);
301 wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
302 tls_msg_len);
303 *pos += 4;
304 *left -= 4;
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305
306 if (*left > tls_msg_len) {
307 wpa_printf(MSG_INFO, "SSL: TLS Message Length (%d "
308 "bytes) smaller than this fragment (%d "
309 "bytes)", (int) tls_msg_len, (int) *left);
310 return -1;
311 }
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312 }
313
314 wpa_printf(MSG_DEBUG, "SSL: Received packet: Flags 0x%x "
315 "Message Length %u", flags, tls_msg_len);
316
317 if (data->state == WAIT_FRAG_ACK) {
318 if (*left != 0) {
319 wpa_printf(MSG_DEBUG, "SSL: Unexpected payload in "
320 "WAIT_FRAG_ACK state");
321 return -1;
322 }
323 wpa_printf(MSG_DEBUG, "SSL: Fragment acknowledged");
324 return 1;
325 }
326
4781064b 327 if (data->tls_in &&
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328 eap_server_tls_process_cont(data, *pos, end - *pos) < 0)
329 return -1;
330
331 if (flags & EAP_TLS_FLAGS_MORE_FRAGMENTS) {
332 if (eap_server_tls_process_fragment(data, flags, tls_msg_len,
333 *pos, end - *pos) < 0)
334 return -1;
335
336 data->state = FRAG_ACK;
337 return 1;
338 }
339
340 if (data->state == FRAG_ACK) {
341 wpa_printf(MSG_DEBUG, "SSL: All fragments received");
342 data->state = MSG;
343 }
344
4781064b 345 if (data->tls_in == NULL) {
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346 /* Wrap unfragmented messages as wpabuf without extra copy */
347 wpabuf_set(&data->tmpbuf, *pos, end - *pos);
4781064b 348 data->tls_in = &data->tmpbuf;
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349 }
350
351 return 0;
352}
353
354
355static void eap_server_tls_free_in_buf(struct eap_ssl_data *data)
356{
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357 if (data->tls_in != &data->tmpbuf)
358 wpabuf_free(data->tls_in);
359 data->tls_in = NULL;
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360}
361
362
363struct wpabuf * eap_server_tls_encrypt(struct eap_sm *sm,
364 struct eap_ssl_data *data,
4781064b 365 const struct wpabuf *plain)
a875087d 366{
a875087d 367 struct wpabuf *buf;
a875087d 368
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369 buf = tls_connection_encrypt(sm->ssl_ctx, data->conn,
370 plain);
371 if (buf == NULL) {
a875087d 372 wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 data");
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373 return NULL;
374 }
375
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376 return buf;
377}
378
379
380int eap_server_tls_process(struct eap_sm *sm, struct eap_ssl_data *data,
381 struct wpabuf *respData, void *priv, int eap_type,
382 int (*proc_version)(struct eap_sm *sm, void *priv,
383 int peer_version),
384 void (*proc_msg)(struct eap_sm *sm, void *priv,
385 const struct wpabuf *respData))
386{
387 const u8 *pos;
388 u8 flags;
389 size_t left;
390 int ret, res = 0;
391
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392 if (eap_type == EAP_UNAUTH_TLS_TYPE)
393 pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
394 EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
395 &left);
396 else
397 pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, respData,
398 &left);
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399 if (pos == NULL || left < 1)
400 return 0; /* Should not happen - frame already validated */
401 flags = *pos++;
402 left--;
403 wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - Flags 0x%02x",
404 (unsigned long) wpabuf_len(respData), flags);
405
406 if (proc_version &&
407 proc_version(sm, priv, flags & EAP_TLS_VERSION_MASK) < 0)
408 return -1;
409
410 ret = eap_server_tls_reassemble(data, flags, &pos, &left);
411 if (ret < 0) {
412 res = -1;
413 goto done;
414 } else if (ret == 1)
415 return 0;
416
417 if (proc_msg)
418 proc_msg(sm, priv, respData);
419
420 if (tls_connection_get_write_alerts(sm->ssl_ctx, data->conn) > 1) {
421 wpa_printf(MSG_INFO, "SSL: Locally detected fatal error in "
422 "TLS processing");
423 res = -1;
424 }
425
426done:
427 eap_server_tls_free_in_buf(data);
428
429 return res;
430}