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 1037 : void eap_fast_put_tlv_hdr(struct wpabuf *buf, u16 type, u16 len)
20 : {
21 : struct pac_tlv_hdr hdr;
22 1037 : hdr.type = host_to_be16(type);
23 1037 : hdr.len = host_to_be16(len);
24 1037 : wpabuf_put_data(buf, &hdr, sizeof(hdr));
25 1037 : }
26 :
27 :
28 411 : void eap_fast_put_tlv(struct wpabuf *buf, u16 type, const void *data,
29 : u16 len)
30 : {
31 411 : eap_fast_put_tlv_hdr(buf, type, len);
32 411 : wpabuf_put_data(buf, data, len);
33 411 : }
34 :
35 :
36 518 : void eap_fast_put_tlv_buf(struct wpabuf *buf, u16 type,
37 : const struct wpabuf *data)
38 : {
39 518 : eap_fast_put_tlv_hdr(buf, type, wpabuf_len(data));
40 518 : wpabuf_put_buf(buf, data);
41 518 : }
42 :
43 :
44 519 : struct wpabuf * eap_fast_tlv_eap_payload(struct wpabuf *buf)
45 : {
46 : struct wpabuf *e;
47 :
48 519 : if (buf == NULL)
49 0 : return NULL;
50 :
51 : /* Encapsulate EAP packet in EAP-Payload TLV */
52 519 : wpa_printf(MSG_DEBUG, "EAP-FAST: Add EAP-Payload TLV");
53 519 : e = wpabuf_alloc(sizeof(struct pac_tlv_hdr) + wpabuf_len(buf));
54 519 : if (e == NULL) {
55 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Failed to allocate memory "
56 : "for TLV encapsulation");
57 1 : wpabuf_free(buf);
58 1 : return NULL;
59 : }
60 518 : eap_fast_put_tlv_buf(e,
61 : EAP_TLV_TYPE_MANDATORY | EAP_TLV_EAP_PAYLOAD_TLV,
62 : buf);
63 518 : wpabuf_free(buf);
64 518 : return e;
65 : }
66 :
67 :
68 72 : 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 72 : wpa_hexdump(MSG_DEBUG, "EAP-FAST: client_random",
76 : client_random, TLS_RANDOM_LEN);
77 72 : 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 72 : os_memcpy(seed, server_random, TLS_RANDOM_LEN);
86 72 : os_memcpy(seed + TLS_RANDOM_LEN, client_random, TLS_RANDOM_LEN);
87 72 : 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 72 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: master_secret",
92 : master_secret, TLS_MASTER_SECRET_LEN);
93 72 : }
94 :
95 :
96 233 : u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn, size_t len)
97 : {
98 : u8 *out;
99 :
100 233 : out = os_malloc(len);
101 233 : if (out == NULL)
102 2 : return NULL;
103 :
104 231 : if (tls_connection_get_eap_fast_key(ssl_ctx, conn, out, len)) {
105 1 : os_free(out);
106 1 : return NULL;
107 : }
108 :
109 230 : return out;
110 : }
111 :
112 :
113 102 : int eap_fast_derive_eap_msk(const u8 *simck, u8 *msk)
114 : {
115 : /*
116 : * RFC 4851, Section 5.4: EAP Master Session Key Generation
117 : * MSK = T-PRF(S-IMCK[j], "Session Key Generating Function", 64)
118 : */
119 :
120 102 : if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
121 : "Session Key Generating Function", (u8 *) "", 0,
122 : msk, EAP_FAST_KEY_LEN) < 0)
123 1 : return -1;
124 101 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (MSK)",
125 : msk, EAP_FAST_KEY_LEN);
126 101 : return 0;
127 : }
128 :
129 :
130 56 : int eap_fast_derive_eap_emsk(const u8 *simck, u8 *emsk)
131 : {
132 : /*
133 : * RFC 4851, Section 5.4: EAP Master Session Key Genreration
134 : * EMSK = T-PRF(S-IMCK[j],
135 : * "Extended Session Key Generating Function", 64)
136 : */
137 :
138 56 : if (sha1_t_prf(simck, EAP_FAST_SIMCK_LEN,
139 : "Extended Session Key Generating Function", (u8 *) "", 0,
140 : emsk, EAP_EMSK_LEN) < 0)
141 1 : return -1;
142 55 : wpa_hexdump_key(MSG_DEBUG, "EAP-FAST: Derived key (EMSK)",
143 : emsk, EAP_EMSK_LEN);
144 55 : return 0;
145 : }
146 :
147 :
148 1170 : int eap_fast_parse_tlv(struct eap_fast_tlv_parse *tlv,
149 : int tlv_type, u8 *pos, size_t len)
150 : {
151 1170 : switch (tlv_type) {
152 : case EAP_TLV_EAP_PAYLOAD_TLV:
153 521 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: EAP-Payload TLV",
154 : pos, len);
155 521 : if (tlv->eap_payload_tlv) {
156 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
157 : "EAP-Payload TLV in the message");
158 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
159 1 : return -2;
160 : }
161 520 : tlv->eap_payload_tlv = pos;
162 520 : tlv->eap_payload_tlv_len = len;
163 520 : break;
164 : case EAP_TLV_RESULT_TLV:
165 218 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Result TLV", pos, len);
166 218 : if (tlv->result) {
167 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
168 : "Result TLV in the message");
169 1 : tlv->result = EAP_TLV_RESULT_FAILURE;
170 1 : return -2;
171 : }
172 217 : if (len < 2) {
173 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
174 : "Result TLV");
175 1 : tlv->result = EAP_TLV_RESULT_FAILURE;
176 1 : break;
177 : }
178 216 : tlv->result = WPA_GET_BE16(pos);
179 222 : if (tlv->result != EAP_TLV_RESULT_SUCCESS &&
180 6 : tlv->result != EAP_TLV_RESULT_FAILURE) {
181 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Result %d",
182 : tlv->result);
183 1 : tlv->result = EAP_TLV_RESULT_FAILURE;
184 : }
185 216 : wpa_printf(MSG_DEBUG, "EAP-FAST: Result: %s",
186 216 : tlv->result == EAP_TLV_RESULT_SUCCESS ?
187 : "Success" : "Failure");
188 216 : break;
189 : case EAP_TLV_INTERMEDIATE_RESULT_TLV:
190 85 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Intermediate Result TLV",
191 : pos, len);
192 85 : if (len < 2) {
193 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
194 : "Intermediate-Result TLV");
195 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
196 1 : break;
197 : }
198 84 : if (tlv->iresult) {
199 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
200 : "Intermediate-Result TLV in the message");
201 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
202 1 : return -2;
203 : }
204 83 : tlv->iresult = WPA_GET_BE16(pos);
205 85 : if (tlv->iresult != EAP_TLV_RESULT_SUCCESS &&
206 2 : tlv->iresult != EAP_TLV_RESULT_FAILURE) {
207 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Unknown Intermediate "
208 : "Result %d", tlv->iresult);
209 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
210 : }
211 83 : wpa_printf(MSG_DEBUG, "EAP-FAST: Intermediate Result: %s",
212 83 : tlv->iresult == EAP_TLV_RESULT_SUCCESS ?
213 : "Success" : "Failure");
214 83 : break;
215 : case EAP_TLV_CRYPTO_BINDING_TLV:
216 185 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Crypto-Binding TLV",
217 : pos, len);
218 185 : if (tlv->crypto_binding) {
219 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
220 : "Crypto-Binding TLV in the message");
221 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
222 1 : return -2;
223 : }
224 184 : tlv->crypto_binding_len = sizeof(struct eap_tlv_hdr) + len;
225 184 : if (tlv->crypto_binding_len < sizeof(*tlv->crypto_binding)) {
226 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
227 : "Crypto-Binding TLV");
228 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
229 1 : return -2;
230 : }
231 183 : tlv->crypto_binding = (struct eap_tlv_crypto_binding_tlv *)
232 : (pos - sizeof(struct eap_tlv_hdr));
233 183 : break;
234 : case EAP_TLV_REQUEST_ACTION_TLV:
235 25 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: Request-Action TLV",
236 : pos, len);
237 25 : if (tlv->request_action) {
238 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
239 : "Request-Action TLV in the message");
240 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
241 1 : return -2;
242 : }
243 24 : if (len < 2) {
244 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: Too short "
245 : "Request-Action TLV");
246 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
247 1 : break;
248 : }
249 23 : tlv->request_action = WPA_GET_BE16(pos);
250 23 : wpa_printf(MSG_DEBUG, "EAP-FAST: Request-Action: %d",
251 : tlv->request_action);
252 23 : break;
253 : case EAP_TLV_PAC_TLV:
254 133 : wpa_hexdump(MSG_MSGDUMP, "EAP-FAST: PAC TLV", pos, len);
255 133 : if (tlv->pac) {
256 1 : wpa_printf(MSG_DEBUG, "EAP-FAST: More than one "
257 : "PAC TLV in the message");
258 1 : tlv->iresult = EAP_TLV_RESULT_FAILURE;
259 1 : return -2;
260 : }
261 132 : tlv->pac = pos;
262 132 : tlv->pac_len = len;
263 132 : break;
264 : default:
265 : /* Unknown TLV */
266 3 : return -1;
267 : }
268 :
269 1160 : return 0;
270 : }
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