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1 /*
2  * Simultaneous authentication of equals
3  * Copyright (c) 2012-2013, 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 #ifndef SAE_H
10 #define SAE_H
11 
12 #define SAE_KCK_LEN 32
13 #define SAE_PMK_LEN 32
14 #define SAE_PMKID_LEN 16
15 #define SAE_MAX_PRIME_LEN 512
16 #define SAE_MAX_ECC_PRIME_LEN 66
17 #define SAE_MAX_HASH_LEN 64
18 #define SAE_COMMIT_MAX_LEN (2 + 3 * SAE_MAX_PRIME_LEN + 255)
19 #define SAE_CONFIRM_MAX_LEN (2 + SAE_MAX_HASH_LEN)
20 
21 /* Special value returned by sae_parse_commit() */
22 #define SAE_SILENTLY_DISCARD 65535
23 
24 struct sae_temporary_data {
25 	u8 kck[SAE_MAX_HASH_LEN];
26 	size_t kck_len;
27 	struct crypto_bignum *own_commit_scalar;
28 	struct crypto_bignum *own_commit_element_ffc;
29 	struct crypto_ec_point *own_commit_element_ecc;
30 	struct crypto_bignum *peer_commit_element_ffc;
31 	struct crypto_ec_point *peer_commit_element_ecc;
32 	struct crypto_ec_point *pwe_ecc;
33 	struct crypto_bignum *pwe_ffc;
34 	struct crypto_bignum *sae_rand;
35 	struct crypto_ec *ec;
36 	int prime_len;
37 	int order_len;
38 	const struct dh_group *dh;
39 	const struct crypto_bignum *prime;
40 	const struct crypto_bignum *order;
41 	struct crypto_bignum *prime_buf;
42 	struct crypto_bignum *order_buf;
43 	struct wpabuf *anti_clogging_token;
44 	char *pw_id;
45 	int vlan_id;
46 	u8 bssid[ETH_ALEN];
47 	struct wpabuf *own_rejected_groups;
48 	struct wpabuf *peer_rejected_groups;
49 	unsigned int h2e:1;
50 	unsigned int own_addr_higher:1;
51 };
52 
53 struct sae_pt {
54 	struct sae_pt *next;
55 	int group;
56 	struct crypto_ec *ec;
57 	struct crypto_ec_point *ecc_pt;
58 
59 	const struct dh_group *dh;
60 	struct crypto_bignum *ffc_pt;
61 };
62 
63 enum sae_state {
64 	SAE_NOTHING, SAE_COMMITTED, SAE_CONFIRMED, SAE_ACCEPTED
65 };
66 
67 struct sae_data {
68 	enum sae_state state;
69 	u16 send_confirm;
70 	u8 pmk[SAE_PMK_LEN];
71 	u8 pmkid[SAE_PMKID_LEN];
72 	struct crypto_bignum *peer_commit_scalar;
73 	struct crypto_bignum *peer_commit_scalar_accepted;
74 	int group;
75 	unsigned int sync; /* protocol instance variable: Sync */
76 	u16 rc; /* protocol instance variable: Rc (received send-confirm) */
77 	struct sae_temporary_data *tmp;
78 };
79 
80 int sae_set_group(struct sae_data *sae, int group);
81 void sae_clear_temp_data(struct sae_data *sae);
82 void sae_clear_data(struct sae_data *sae);
83 
84 int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
85 		       const u8 *password, size_t password_len,
86 		       const char *identifier, struct sae_data *sae);
87 int sae_prepare_commit_pt(struct sae_data *sae, const struct sae_pt *pt,
88 			  const u8 *addr1, const u8 *addr2,
89 			  int *rejected_groups);
90 int sae_process_commit(struct sae_data *sae);
91 int sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
92 		     const struct wpabuf *token, const char *identifier);
93 u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
94 		     const u8 **token, size_t *token_len, int *allowed_groups,
95 		     int h2e);
96 void sae_write_confirm(struct sae_data *sae, struct wpabuf *buf);
97 int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len);
98 u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups, u16 group);
99 const char * sae_state_txt(enum sae_state state);
100 struct sae_pt * sae_derive_pt(int *groups, const u8 *ssid, size_t ssid_len,
101 			      const u8 *password, size_t password_len,
102 			      const char *identifier);
103 struct crypto_ec_point *
104 sae_derive_pwe_from_pt_ecc(const struct sae_pt *pt,
105 			   const u8 *addr1, const u8 *addr2);
106 struct crypto_bignum *
107 sae_derive_pwe_from_pt_ffc(const struct sae_pt *pt,
108 			   const u8 *addr1, const u8 *addr2);
109 void sae_deinit_pt(struct sae_pt *pt);
110 
111 #endif /* SAE_H */
112