Line data Source code
1 : /*
2 : * EAP-FAST common helper functions (RFC 4851)
3 : * Copyright (c) 2008, 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 "crypto/sha1.h"
13 : #include "crypto/tls.h"
14 : #include "eap_defs.h"
15 : #include "eap_tlv_common.h"
16 : #include "eap_fast_common.h"
17 :
18 :
19 179 : void eap_fast_put_tlv_hdr(struct wpabuf *buf, u16 type, u16 len)
20 : {
21 : struct pac_tlv_hdr hdr;
22 179 : hdr.type = host_to_be16(type);
23 179 : hdr.len = host_to_be16(len);
24 179 : wpabuf_put_data(buf, &hdr, sizeof(hdr));
25 179 : }
26 :
27 :
28 65 : void eap_fast_put_tlv(struct wpabuf *buf, u16 type, const void *data,
29 : u16 len)
30 : {
31 65 : eap_fast_put_tlv_hdr(buf, type, len);
32 65 : wpabuf_put_data(buf, data, len);
33 65 : }
34 :
35 :
36 96 : void eap_fast_put_tlv_buf(struct wpabuf *buf, u16 type,
37 : const struct wpabuf *data)
38 : {
39 96 : eap_fast_put_tlv_hdr(buf, type, wpabuf_len(data));
40 96 : wpabuf_put_buf(buf, data);
41 96 : }
42 :
43 :
44 96 : struct wpabuf * eap_fast_tlv_eap_payload(struct wpabuf *buf)
45 : {
46 : struct wpabuf *e;
47 :
48 96 : if (buf == NULL)
49 0 : return NULL;
50 :
51 : /* Encapsulate EAP packet in EAP-Payload TLV */
52 96 : wpa_printf(MSG_DEBUG, "EAP-FAST: Add EAP-Payload TLV");
53 96 : e = wpabuf_alloc(sizeof(struct pac_tlv_hdr) + wpabuf_len(buf));
54 96 : if (e == NULL) {
55 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to allocate memory "
56 : "for TLV encapsulation");
57 0 : wpabuf_free(buf);
58 0 : return NULL;
59 : }
60 96 : eap_fast_put_tlv_buf(e,
61 : EAP_TLV_TYPE_MANDATORY | EAP_TLV_EAP_PAYLOAD_TLV,
62 : buf);
63 96 : wpabuf_free(buf);
64 96 : return e;
65 : }
66 :
67 :
68 18 : void eap_fast_derive_master_secret(const u8 *pac_key, const u8 *server_random,
69 : const u8 *client_random, u8 *master_secret)
70 : {
71 : #define TLS_RANDOM_LEN 32
72 : #define TLS_MASTER_SECRET_LEN 48
73 : u8 seed[2 * TLS_RANDOM_LEN];
74 :
75 18 : wpa_hexdump(MSG_DEBUG, "EAP-FAST: client_random",
76 : client_random, TLS_RANDOM_LEN);
77 18 : wpa_hexdump(MSG_DEBUG, "EAP-FAST: server_random",
78 : server_random, TLS_RANDOM_LEN);
79 :
80 : /*
81 : * RFC 4851, Section 5.1:
82 : * master_secret = T-PRF(PAC-Key, "PAC to master secret label hash",
83 : * server_random + client_random, 48)
84 : */
85 18 : os_memcpy(seed, server_random, TLS_RANDOM_LEN);
86 18 : os_memcpy(seed + TLS_RANDOM_LEN, client_random, TLS_RANDOM_LEN);
87 18 : sha1_t_prf(pac_key, EAP_FAST_PAC_KEY_LEN,
88 : "PAC to master secret label hash",
89 : seed, sizeof(seed), master_secret, TLS_MASTER_SECRET_LEN);
90 :
91 18 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: master_secret",
92 : master_secret, TLS_MASTER_SECRET_LEN);
93 18 : }
94 :
95 :
96 36 : u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn,
97 : const char *label, size_t len)
98 : {
99 : struct tls_keys keys;
100 36 : u8 *rnd = NULL, *out;
101 : int block_size;
102 :
103 36 : block_size = tls_connection_get_keyblock_size(ssl_ctx, conn);
104 36 : if (block_size < 0)
105 0 : return NULL;
106 :
107 36 : out = os_malloc(block_size + len);
108 36 : if (out == NULL)
109 0 : return NULL;
110 :
111 36 : if (tls_connection_prf(ssl_ctx, conn, label, 1, out, block_size + len)
112 : == 0) {
113 0 : os_memmove(out, out + block_size, len);
114 0 : return out;
115 : }
116 :
117 36 : if (tls_connection_get_keys(ssl_ctx, conn, &keys))
118 0 : goto fail;
119 :
120 36 : rnd = os_malloc(keys.client_random_len + keys.server_random_len);
121 36 : if (rnd == NULL)
122 0 : goto fail;
123 :
124 36 : os_memcpy(rnd, keys.server_random, keys.server_random_len);
125 36 : os_memcpy(rnd + keys.server_random_len, keys.client_random,
126 : keys.client_random_len);
127 :
128 72 : wpa_hexdump_key(MSG_MSGDUMP, "EAP-FAST: master_secret for key "
129 36 : "expansion", keys.master_key, keys.master_key_len);
130 72 : if (tls_prf_sha1_md5(keys.master_key, keys.master_key_len,
131 36 : label, rnd, keys.client_random_len +
132 36 : keys.server_random_len, out, block_size + len))
133 0 : goto fail;
134 36 : os_free(rnd);
135 36 : os_memmove(out, out + block_size, len);
136 36 : return out;
137 :
138 : fail:
139 0 : os_free(rnd);
140 0 : os_free(out);
141 0 : return NULL;
142 : }
143 :
144 :
145 29 : void eap_fast_derive_eap_msk(const u8 *simck, u8 *msk)
146 : {
147 : /*
148 : * RFC 4851, Section 5.4: EAP Master Session Key Generation
149 : * MSK = T-PRF(S-IMCK[j], "Session Key Generating Function", 64)
150 : */
151 :
152 29 : sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
153 : "Session Key Generating Function", (u8 *) "", 0,
154 : msk, EAP_FAST_KEY_LEN);
155 29 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (MSK)",
156 : msk, EAP_FAST_KEY_LEN);
157 29 : }
158 :
159 :
160 15 : void eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk)
161 : {
162 : /*
163 : * RFC 4851, Section 5.4: EAP Master Session Key Genreration
164 : * EMSK = T-PRF(S-IMCK[j],
165 : * "Extended Session Key Generating Function", 64)
166 : */
167 :
168 15 : sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
169 : "Extended Session Key Generating Function", (u8 *) "", 0,
170 : emsk, EAP_EMSK_LEN);
171 15 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (EMSK)",
172 : emsk, EAP_EMSK_LEN);
173 15 : }
174 :
175 :
176 223 : int eap_fast_parse_tlv(struct eap_fast_tlv_parse *tlv,
177 : int tlv_type, u8 *pos, int len)
178 : {
179 223 : switch (tlv_type) {
180 : case EAP_TLV_EAP_PAYLOAD_TLV:
181 97 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: EAP-Payload TLV",
182 : pos, len);
183 97 : if (tlv->eap_payload_tlv) {
184 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
185 : "EAP-Payload TLV in the message");
186 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
187 0 : return -2;
188 : }
189 97 : tlv->eap_payload_tlv = pos;
190 97 : tlv->eap_payload_tlv_len = len;
191 97 : break;
192 : case EAP_TLV_RESULT_TLV:
193 46 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Result TLV", pos, len);
194 46 : if (tlv->result) {
195 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
196 : "Result TLV in the message");
197 0 : tlv->result = EAP_TLV_RESULT_FAILURE;
198 0 : return -2;
199 : }
200 46 : if (len < 2) {
201 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
202 : "Result TLV");
203 0 : tlv->result = EAP_TLV_RESULT_FAILURE;
204 0 : break;
205 : }
206 46 : tlv->result = WPA_GET_BE16(pos);
207 46 : if (tlv->result != EAP_TLV_RESULT_SUCCESS &&
208 0 : tlv->result != EAP_TLV_RESULT_FAILURE) {
209 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Result %d",
210 : tlv->result);
211 0 : tlv->result = EAP_TLV_RESULT_FAILURE;
212 : }
213 46 : wpa_printf(MSG_DEBUG, "EAP-FAST: Result: %s",
214 46 : tlv->result == EAP_TLV_RESULT_SUCCESS ?
215 : "Success" : "Failure");
216 46 : break;
217 : case EAP_TLV_INTERMEDIATE_RESULT_TLV:
218 12 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Intermediate Result TLV",
219 : pos, len);
220 12 : if (len < 2) {
221 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
222 : "Intermediate-Result TLV");
223 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
224 0 : break;
225 : }
226 12 : if (tlv->iresult) {
227 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
228 : "Intermediate-Result TLV in the message");
229 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
230 0 : return -2;
231 : }
232 12 : tlv->iresult = WPA_GET_BE16(pos);
233 12 : if (tlv->iresult != EAP_TLV_RESULT_SUCCESS &&
234 0 : tlv->iresult != EAP_TLV_RESULT_FAILURE) {
235 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Intermediate "
236 : "Result %d", tlv->iresult);
237 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
238 : }
239 12 : wpa_printf(MSG_DEBUG, "EAP-FAST: Intermediate Result: %s",
240 12 : tlv->iresult == EAP_TLV_RESULT_SUCCESS ?
241 : "Success" : "Failure");
242 12 : break;
243 : case EAP_TLV_CRYPTO_BINDING_TLV:
244 38 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV",
245 : pos, len);
246 38 : if (tlv->crypto_binding) {
247 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
248 : "Crypto-Binding TLV in the message");
249 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
250 0 : return -2;
251 : }
252 38 : tlv->crypto_binding_len = sizeof(struct eap_tlv_hdr) + len;
253 38 : if (tlv->crypto_binding_len < sizeof(*tlv->crypto_binding)) {
254 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
255 : "Crypto-Binding TLV");
256 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
257 0 : return -2;
258 : }
259 38 : tlv->crypto_binding = (struct eap_tlv_crypto_binding_tlv *)
260 : (pos - sizeof(struct eap_tlv_hdr));
261 38 : break;
262 : case EAP_TLV_REQUEST_ACTION_TLV:
263 6 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Request-Action TLV",
264 : pos, len);
265 6 : if (tlv->request_action) {
266 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
267 : "Request-Action TLV in the message");
268 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
269 0 : return -2;
270 : }
271 6 : if (len < 2) {
272 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
273 : "Request-Action TLV");
274 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
275 0 : break;
276 : }
277 6 : tlv->request_action = WPA_GET_BE16(pos);
278 6 : wpa_printf(MSG_DEBUG, "EAP-FAST: Request-Action: %d",
279 : tlv->request_action);
280 6 : break;
281 : case EAP_TLV_PAC_TLV:
282 24 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: PAC TLV", pos, len);
283 24 : if (tlv->pac) {
284 0 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
285 : "PAC TLV in the message");
286 0 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
287 0 : return -2;
288 : }
289 24 : tlv->pac = pos;
290 24 : tlv->pac_len = len;
291 24 : break;
292 : default:
293 : /* Unknown TLV */
294 0 : return -1;
295 : }
296 :
297 223 : return 0;
298 : }
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