Disconnect hostapd from building in base
[dragonfly.git] / contrib / hostapd / src / eap_common / eap_sake_common.c
CommitLineData
ebfa2275
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1/*
2 * EAP server/peer: EAP-SAKE shared routines
a875087d 3 * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
ebfa2275 4 *
4781064b
JM
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"
a875087d 12#include "wpabuf.h"
4781064b 13#include "crypto/sha1.h"
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14#include "eap_defs.h"
15#include "eap_sake_common.h"
16
17
18static int eap_sake_parse_add_attr(struct eap_sake_parse_attr *attr,
19 const u8 *pos)
20{
21 size_t i;
22
23 switch (pos[0]) {
24 case EAP_SAKE_AT_RAND_S:
25 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_RAND_S");
26 if (pos[1] != 2 + EAP_SAKE_RAND_LEN) {
27 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_RAND_S with "
28 "invalid length %d", pos[1]);
29 return -1;
30 }
31 attr->rand_s = pos + 2;
32 break;
33 case EAP_SAKE_AT_RAND_P:
34 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_RAND_P");
35 if (pos[1] != 2 + EAP_SAKE_RAND_LEN) {
36 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_RAND_P with "
37 "invalid length %d", pos[1]);
38 return -1;
39 }
40 attr->rand_p = pos + 2;
41 break;
42 case EAP_SAKE_AT_MIC_S:
43 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_MIC_S");
44 if (pos[1] != 2 + EAP_SAKE_MIC_LEN) {
45 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_MIC_S with "
46 "invalid length %d", pos[1]);
47 return -1;
48 }
49 attr->mic_s = pos + 2;
50 break;
51 case EAP_SAKE_AT_MIC_P:
52 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_MIC_P");
53 if (pos[1] != 2 + EAP_SAKE_MIC_LEN) {
54 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_MIC_P with "
55 "invalid length %d", pos[1]);
56 return -1;
57 }
58 attr->mic_p = pos + 2;
59 break;
60 case EAP_SAKE_AT_SERVERID:
61 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SERVERID");
62 attr->serverid = pos + 2;
63 attr->serverid_len = pos[1] - 2;
64 break;
65 case EAP_SAKE_AT_PEERID:
66 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PEERID");
67 attr->peerid = pos + 2;
68 attr->peerid_len = pos[1] - 2;
69 break;
70 case EAP_SAKE_AT_SPI_S:
71 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SPI_S");
72 attr->spi_s = pos + 2;
73 attr->spi_s_len = pos[1] - 2;
74 break;
75 case EAP_SAKE_AT_SPI_P:
76 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_SPI_P");
77 attr->spi_p = pos + 2;
78 attr->spi_p_len = pos[1] - 2;
79 break;
80 case EAP_SAKE_AT_ANY_ID_REQ:
81 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_ANY_ID_REQ");
82 if (pos[1] != 4) {
83 wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid AT_ANY_ID_REQ"
84 " length %d", pos[1]);
85 return -1;
86 }
87 attr->any_id_req = pos + 2;
88 break;
89 case EAP_SAKE_AT_PERM_ID_REQ:
90 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PERM_ID_REQ");
91 if (pos[1] != 4) {
92 wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid "
93 "AT_PERM_ID_REQ length %d", pos[1]);
94 return -1;
95 }
96 attr->perm_id_req = pos + 2;
97 break;
98 case EAP_SAKE_AT_ENCR_DATA:
99 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_ENCR_DATA");
100 attr->encr_data = pos + 2;
101 attr->encr_data_len = pos[1] - 2;
102 break;
103 case EAP_SAKE_AT_IV:
104 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_IV");
105 attr->iv = pos + 2;
106 attr->iv_len = pos[1] - 2;
107 break;
108 case EAP_SAKE_AT_PADDING:
109 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_PADDING");
110 for (i = 2; i < pos[1]; i++) {
111 if (pos[i]) {
112 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_PADDING "
113 "with non-zero pad byte");
114 return -1;
115 }
116 }
117 break;
118 case EAP_SAKE_AT_NEXT_TMPID:
119 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_NEXT_TMPID");
120 attr->next_tmpid = pos + 2;
121 attr->next_tmpid_len = pos[1] - 2;
122 break;
123 case EAP_SAKE_AT_MSK_LIFE:
124 wpa_printf(MSG_DEBUG, "EAP-SAKE: Parse: AT_IV");
125 if (pos[1] != 6) {
126 wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid "
127 "AT_MSK_LIFE length %d", pos[1]);
128 return -1;
129 }
130 attr->msk_life = pos + 2;
131 break;
132 default:
133 if (pos[0] < 128) {
134 wpa_printf(MSG_DEBUG, "EAP-SAKE: Unknown non-skippable"
135 " attribute %d", pos[0]);
136 return -1;
137 }
138 wpa_printf(MSG_DEBUG, "EAP-SAKE: Ignoring unknown skippable "
139 "attribute %d", pos[0]);
140 break;
141 }
142
143 if (attr->iv && !attr->encr_data) {
144 wpa_printf(MSG_DEBUG, "EAP-SAKE: AT_IV included without "
145 "AT_ENCR_DATA");
146 return -1;
147 }
148
149 return 0;
150}
151
152
153/**
154 * eap_sake_parse_attributes - Parse EAP-SAKE attributes
155 * @buf: Packet payload (starting with the first attribute)
156 * @len: Payload length
157 * @attr: Structure to be filled with found attributes
158 * Returns: 0 on success or -1 on failure
159 */
160int eap_sake_parse_attributes(const u8 *buf, size_t len,
161 struct eap_sake_parse_attr *attr)
162{
163 const u8 *pos = buf, *end = buf + len;
164
165 os_memset(attr, 0, sizeof(*attr));
166 while (pos < end) {
167 if (end - pos < 2) {
168 wpa_printf(MSG_DEBUG, "EAP-SAKE: Too short attribute");
169 return -1;
170 }
171
172 if (pos[1] < 2) {
173 wpa_printf(MSG_DEBUG, "EAP-SAKE: Invalid attribute "
174 "length (%d)", pos[1]);
175 return -1;
176 }
177
178 if (pos + pos[1] > end) {
179 wpa_printf(MSG_DEBUG, "EAP-SAKE: Attribute underflow");
180 return -1;
181 }
182
183 if (eap_sake_parse_add_attr(attr, pos))
184 return -1;
185
186 pos += pos[1];
187 }
188
189 return 0;
190}
191
192
193/**
194 * eap_sake_kdf - EAP-SAKE Key Derivation Function (KDF)
195 * @key: Key for KDF
196 * @key_len: Length of the key in bytes
197 * @label: A unique label for each purpose of the KDF
198 * @data: Extra data (start) to bind into the key
199 * @data_len: Length of the data
200 * @data2: Extra data (end) to bind into the key
201 * @data2_len: Length of the data2
202 * @buf: Buffer for the generated pseudo-random key
203 * @buf_len: Number of bytes of key to generate
204 *
205 * This function is used to derive new, cryptographically separate keys from a
206 * given key (e.g., SMS). This is identical to the PRF used in IEEE 802.11i.
207 */
208static void eap_sake_kdf(const u8 *key, size_t key_len, const char *label,
209 const u8 *data, size_t data_len,
210 const u8 *data2, size_t data2_len,
211 u8 *buf, size_t buf_len)
212{
213 u8 counter = 0;
214 size_t pos, plen;
215 u8 hash[SHA1_MAC_LEN];
216 size_t label_len = os_strlen(label) + 1;
217 const unsigned char *addr[4];
218 size_t len[4];
219
220 addr[0] = (u8 *) label; /* Label | Y */
221 len[0] = label_len;
222 addr[1] = data; /* Msg[start] */
223 len[1] = data_len;
224 addr[2] = data2; /* Msg[end] */
225 len[2] = data2_len;
226 addr[3] = &counter; /* Length */
227 len[3] = 1;
228
229 pos = 0;
230 while (pos < buf_len) {
231 plen = buf_len - pos;
232 if (plen >= SHA1_MAC_LEN) {
233 hmac_sha1_vector(key, key_len, 4, addr, len,
234 &buf[pos]);
235 pos += SHA1_MAC_LEN;
236 } else {
237 hmac_sha1_vector(key, key_len, 4, addr, len,
238 hash);
239 os_memcpy(&buf[pos], hash, plen);
240 break;
241 }
242 counter++;
243 }
244}
245
246
247/**
248 * eap_sake_derive_keys - Derive EAP-SAKE keys
249 * @root_secret_a: 16-byte Root-Secret-A
250 * @root_secret_b: 16-byte Root-Secret-B
251 * @rand_s: 16-byte RAND_S
252 * @rand_p: 16-byte RAND_P
253 * @tek: Buffer for Temporary EAK Keys (TEK-Auth[16] | TEK-Cipher[16])
254 * @msk: Buffer for 64-byte MSK
255 * @emsk: Buffer for 64-byte EMSK
256 *
257 * This function derives EAP-SAKE keys as defined in RFC 4763, section 3.2.6.
258 */
259void eap_sake_derive_keys(const u8 *root_secret_a, const u8 *root_secret_b,
260 const u8 *rand_s, const u8 *rand_p, u8 *tek, u8 *msk,
261 u8 *emsk)
262{
263 u8 sms_a[EAP_SAKE_SMS_LEN];
264 u8 sms_b[EAP_SAKE_SMS_LEN];
265 u8 key_buf[EAP_MSK_LEN + EAP_EMSK_LEN];
266
267 wpa_printf(MSG_DEBUG, "EAP-SAKE: Deriving keys");
268
269 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: Root-Secret-A",
270 root_secret_a, EAP_SAKE_ROOT_SECRET_LEN);
271 eap_sake_kdf(root_secret_a, EAP_SAKE_ROOT_SECRET_LEN,
272 "SAKE Master Secret A",
273 rand_p, EAP_SAKE_RAND_LEN, rand_s, EAP_SAKE_RAND_LEN,
274 sms_a, EAP_SAKE_SMS_LEN);
275 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: SMS-A", sms_a, EAP_SAKE_SMS_LEN);
276 eap_sake_kdf(sms_a, EAP_SAKE_SMS_LEN, "Transient EAP Key",
277 rand_s, EAP_SAKE_RAND_LEN, rand_p, EAP_SAKE_RAND_LEN,
278 tek, EAP_SAKE_TEK_LEN);
279 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: TEK-Auth",
280 tek, EAP_SAKE_TEK_AUTH_LEN);
281 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: TEK-Cipher",
282 tek + EAP_SAKE_TEK_AUTH_LEN, EAP_SAKE_TEK_CIPHER_LEN);
283
284 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: Root-Secret-B",
285 root_secret_b, EAP_SAKE_ROOT_SECRET_LEN);
286 eap_sake_kdf(root_secret_b, EAP_SAKE_ROOT_SECRET_LEN,
287 "SAKE Master Secret B",
288 rand_p, EAP_SAKE_RAND_LEN, rand_s, EAP_SAKE_RAND_LEN,
289 sms_b, EAP_SAKE_SMS_LEN);
290 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: SMS-B", sms_b, EAP_SAKE_SMS_LEN);
291 eap_sake_kdf(sms_b, EAP_SAKE_SMS_LEN, "Master Session Key",
292 rand_s, EAP_SAKE_RAND_LEN, rand_p, EAP_SAKE_RAND_LEN,
293 key_buf, sizeof(key_buf));
294 os_memcpy(msk, key_buf, EAP_MSK_LEN);
295 os_memcpy(emsk, key_buf + EAP_MSK_LEN, EAP_EMSK_LEN);
296 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: MSK", msk, EAP_MSK_LEN);
297 wpa_hexdump_key(MSG_DEBUG, "EAP-SAKE: EMSK", emsk, EAP_EMSK_LEN);
298}
299
300
301/**
302 * eap_sake_compute_mic - Compute EAP-SAKE MIC for an EAP packet
303 * @tek_auth: 16-byte TEK-Auth
304 * @rand_s: 16-byte RAND_S
305 * @rand_p: 16-byte RAND_P
306 * @serverid: SERVERID
307 * @serverid_len: SERVERID length
308 * @peerid: PEERID
309 * @peerid_len: PEERID length
310 * @peer: MIC calculation for 0 = Server, 1 = Peer message
311 * @eap: EAP packet
312 * @eap_len: EAP packet length
313 * @mic_pos: MIC position in the EAP packet (must be [eap .. eap + eap_len])
314 * @mic: Buffer for the computed 16-byte MIC
315 */
316int eap_sake_compute_mic(const u8 *tek_auth,
317 const u8 *rand_s, const u8 *rand_p,
318 const u8 *serverid, size_t serverid_len,
319 const u8 *peerid, size_t peerid_len,
320 int peer, const u8 *eap, size_t eap_len,
321 const u8 *mic_pos, u8 *mic)
322{
323 u8 _rand[2 * EAP_SAKE_RAND_LEN];
324 u8 *tmp, *pos;
325 size_t tmplen;
326
327 tmplen = serverid_len + 1 + peerid_len + 1 + eap_len;
328 tmp = os_malloc(tmplen);
329 if (tmp == NULL)
330 return -1;
331 pos = tmp;
332 if (peer) {
333 if (peerid) {
334 os_memcpy(pos, peerid, peerid_len);
335 pos += peerid_len;
336 }
337 *pos++ = 0x00;
338 if (serverid) {
339 os_memcpy(pos, serverid, serverid_len);
340 pos += serverid_len;
341 }
342 *pos++ = 0x00;
343
344 os_memcpy(_rand, rand_s, EAP_SAKE_RAND_LEN);
345 os_memcpy(_rand + EAP_SAKE_RAND_LEN, rand_p,
346 EAP_SAKE_RAND_LEN);
347 } else {
348 if (serverid) {
349 os_memcpy(pos, serverid, serverid_len);
350 pos += serverid_len;
351 }
352 *pos++ = 0x00;
353 if (peerid) {
354 os_memcpy(pos, peerid, peerid_len);
355 pos += peerid_len;
356 }
357 *pos++ = 0x00;
358
359 os_memcpy(_rand, rand_p, EAP_SAKE_RAND_LEN);
360 os_memcpy(_rand + EAP_SAKE_RAND_LEN, rand_s,
361 EAP_SAKE_RAND_LEN);
362 }
363
364 os_memcpy(pos, eap, eap_len);
365 os_memset(pos + (mic_pos - eap), 0, EAP_SAKE_MIC_LEN);
366
367 eap_sake_kdf(tek_auth, EAP_SAKE_TEK_AUTH_LEN,
368 peer ? "Peer MIC" : "Server MIC",
369 _rand, 2 * EAP_SAKE_RAND_LEN, tmp, tmplen,
370 mic, EAP_SAKE_MIC_LEN);
371
372 os_free(tmp);
373
374 return 0;
375}
a875087d
JL
376
377
378void eap_sake_add_attr(struct wpabuf *buf, u8 type, const u8 *data,
379 size_t len)
380{
381 wpabuf_put_u8(buf, type);
382 wpabuf_put_u8(buf, 2 + len); /* Length; including attr header */
383 if (data)
384 wpabuf_put_data(buf, data, len);
385 else
386 os_memset(wpabuf_put(buf, len), 0, len);
387}