1 /*
2  * EAP-IKEv2 common routines
3  * Copyright (c) 2007, Jouni Malinen <j@w1.fi>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 
17 #include "common.h"
18 #include "eap_defs.h"
19 #include "eap_common.h"
20 #include "ikev2_common.h"
21 #include "eap_ikev2_common.h"
22 
23 
24 int eap_ikev2_derive_keymat(int prf, struct ikev2_keys *keys,
25 			    const u8 *i_nonce, size_t i_nonce_len,
26 			    const u8 *r_nonce, size_t r_nonce_len,
27 			    u8 *keymat)
28 {
29 	u8 *nonces;
30 	size_t nlen;
31 
32 	/* KEYMAT = prf+(SK_d, Ni | Nr) */
33 	if (keys->SK_d == NULL || i_nonce == NULL || r_nonce == NULL)
34 		return -1;
35 
36 	nlen = i_nonce_len + r_nonce_len;
37 	nonces = os_malloc(nlen);
38 	if (nonces == NULL)
39 		return -1;
40 	os_memcpy(nonces, i_nonce, i_nonce_len);
41 	os_memcpy(nonces + i_nonce_len, r_nonce, r_nonce_len);
42 
43 	if (ikev2_prf_plus(prf, keys->SK_d, keys->SK_d_len, nonces, nlen,
44 			   keymat, EAP_MSK_LEN + EAP_EMSK_LEN)) {
45 		os_free(nonces);
46 		return -1;
47 	}
48 	os_free(nonces);
49 
50 	wpa_hexdump_key(MSG_DEBUG, "EAP-IKEV2: KEYMAT",
51 			keymat, EAP_MSK_LEN + EAP_EMSK_LEN);
52 
53 	return 0;
54 }
55 
56 
57 struct wpabuf * eap_ikev2_build_frag_ack(u8 id, u8 code)
58 {
59 	struct wpabuf *msg;
60 
61 #ifdef CCNS_PL
62 	msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 1, code, id);
63 	if (msg == NULL) {
64 		wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
65 			   "for fragment ack");
66 		return NULL;
67 	}
68 	wpabuf_put_u8(msg, 0); /* Flags */
69 #else /* CCNS_PL */
70 	msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_IKEV2, 0, code, id);
71 	if (msg == NULL) {
72 		wpa_printf(MSG_ERROR, "EAP-IKEV2: Failed to allocate memory "
73 			   "for fragment ack");
74 		return NULL;
75 	}
76 #endif /* CCNS_PL */
77 
78 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Send fragment ack");
79 
80 	return msg;
81 }
82 
83 
84 int eap_ikev2_validate_icv(int integ_alg, struct ikev2_keys *keys,
85 			   int initiator, const struct wpabuf *msg,
86 			   const u8 *pos, const u8 *end)
87 {
88 	const struct ikev2_integ_alg *integ;
89 	size_t icv_len;
90 	u8 icv[IKEV2_MAX_HASH_LEN];
91 	const u8 *SK_a = initiator ? keys->SK_ai : keys->SK_ar;
92 
93 	integ = ikev2_get_integ(integ_alg);
94 	if (integ == NULL) {
95 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Unknown INTEG "
96 			   "transform / cannot validate ICV");
97 		return -1;
98 	}
99 	icv_len = integ->hash_len;
100 
101 	if (end - pos < (int) icv_len) {
102 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: Not enough room in the "
103 			   "message for Integrity Checksum Data");
104 		return -1;
105 	}
106 
107 	if (SK_a == NULL) {
108 		wpa_printf(MSG_DEBUG, "EAP-IKEV2: No SK_a for ICV validation");
109 		return -1;
110 	}
111 
112 	if (ikev2_integ_hash(integ_alg, SK_a, keys->SK_integ_len,
113 			     wpabuf_head(msg),
114 			     wpabuf_len(msg) - icv_len, icv) < 0) {
115 		wpa_printf(MSG_INFO, "EAP-IKEV2: Could not calculate ICV");
116 		return -1;
117 	}
118 
119 	if (os_memcmp(icv, end - icv_len, icv_len) != 0) {
120 		wpa_printf(MSG_INFO, "EAP-IKEV2: Invalid ICV");
121 		wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Calculated ICV",
122 			    icv, icv_len);
123 		wpa_hexdump(MSG_DEBUG, "EAP-IKEV2: Received ICV",
124 			    end - icv_len, icv_len);
125 		return -1;
126 	}
127 
128 	wpa_printf(MSG_DEBUG, "EAP-IKEV2: Valid Integrity Checksum Data in "
129 		   "the received message");
130 
131 	return icv_len;
132 }
133