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#ifdef CONFIG_SAE_PK
20#define SAE_CONFIRM_MAX_LEN ((2 + SAE_MAX_HASH_LEN) + 1500)
21#else /* CONFIG_SAE_PK */
22#define SAE_CONFIRM_MAX_LEN (2 + SAE_MAX_HASH_LEN)
23#endif /* CONFIG_SAE_PK */
24#define SAE_PK_M_LEN 16
25
26/* Special value returned by sae_parse_commit() */
27#define SAE_SILENTLY_DISCARD 65535
28
29struct sae_pk {
30	struct wpabuf *m;
31	struct crypto_ec_key *key;
32	int group;
33	struct wpabuf *pubkey; /* DER encoded subjectPublicKey */
34#ifdef CONFIG_TESTING_OPTIONS
35	struct crypto_ec_key *sign_key_override;
36#endif /* CONFIG_TESTING_OPTIONS */
37};
38
39
40struct sae_temporary_data {
41	u8 kck[SAE_MAX_HASH_LEN];
42	size_t kck_len;
43	struct crypto_bignum *own_commit_scalar;
44	struct crypto_bignum *own_commit_element_ffc;
45	struct crypto_ec_point *own_commit_element_ecc;
46	struct crypto_bignum *peer_commit_element_ffc;
47	struct crypto_ec_point *peer_commit_element_ecc;
48	struct crypto_ec_point *pwe_ecc;
49	struct crypto_bignum *pwe_ffc;
50	struct crypto_bignum *sae_rand;
51	struct crypto_ec *ec;
52	int prime_len;
53	int order_len;
54	const struct dh_group *dh;
55	const struct crypto_bignum *prime;
56	const struct crypto_bignum *order;
57	struct crypto_bignum *prime_buf;
58	struct crypto_bignum *order_buf;
59	struct wpabuf *anti_clogging_token;
60	char *pw_id;
61	int vlan_id;
62	u8 bssid[ETH_ALEN];
63	struct wpabuf *own_rejected_groups;
64	struct wpabuf *peer_rejected_groups;
65	unsigned int own_addr_higher:1;
66
67#ifdef CONFIG_SAE_PK
68	u8 kek[SAE_MAX_HASH_LEN];
69	size_t kek_len;
70	const struct sae_pk *ap_pk;
71	u8 own_addr[ETH_ALEN];
72	u8 peer_addr[ETH_ALEN];
73	u8 fingerprint[SAE_MAX_HASH_LEN];
74	size_t fingerprint_bytes;
75	size_t fingerprint_bits;
76	size_t lambda;
77	unsigned int sec;
78	u8 ssid[32];
79	size_t ssid_len;
80#ifdef CONFIG_TESTING_OPTIONS
81	bool omit_pk_elem;
82#endif /* CONFIG_TESTING_OPTIONS */
83#endif /* CONFIG_SAE_PK */
84};
85
86struct sae_pt {
87	struct sae_pt *next;
88	int group;
89	struct crypto_ec *ec;
90	struct crypto_ec_point *ecc_pt;
91
92	const struct dh_group *dh;
93	struct crypto_bignum *ffc_pt;
94#ifdef CONFIG_SAE_PK
95	u8 ssid[32];
96	size_t ssid_len;
97#endif /* CONFIG_SAE_PK */
98};
99
100enum sae_state {
101	SAE_NOTHING, SAE_COMMITTED, SAE_CONFIRMED, SAE_ACCEPTED
102};
103
104struct sae_data {
105	enum sae_state state;
106	u16 send_confirm;
107	u8 pmk[SAE_PMK_LEN];
108	u8 pmkid[SAE_PMKID_LEN];
109	struct crypto_bignum *peer_commit_scalar;
110	struct crypto_bignum *peer_commit_scalar_accepted;
111	int group;
112	unsigned int sync; /* protocol instance variable: Sync */
113	u16 rc; /* protocol instance variable: Rc (received send-confirm) */
114	unsigned int h2e:1;
115	unsigned int pk:1;
116	struct sae_temporary_data *tmp;
117};
118
119int sae_set_group(struct sae_data *sae, int group);
120void sae_clear_temp_data(struct sae_data *sae);
121void sae_clear_data(struct sae_data *sae);
122
123int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
124		       const u8 *password, size_t password_len,
125		       struct sae_data *sae);
126int sae_prepare_commit_pt(struct sae_data *sae, const struct sae_pt *pt,
127			  const u8 *addr1, const u8 *addr2,
128			  int *rejected_groups, const struct sae_pk *pk);
129int sae_process_commit(struct sae_data *sae);
130int sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
131		     const struct wpabuf *token, const char *identifier);
132u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
133		     const u8 **token, size_t *token_len, int *allowed_groups,
134		     int h2e);
135int sae_write_confirm(struct sae_data *sae, struct wpabuf *buf);
136int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len);
137u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups, u16 group);
138const char * sae_state_txt(enum sae_state state);
139size_t sae_ecc_prime_len_2_hash_len(size_t prime_len);
140size_t sae_ffc_prime_len_2_hash_len(size_t prime_len);
141struct sae_pt * sae_derive_pt(int *groups, const u8 *ssid, size_t ssid_len,
142			      const u8 *password, size_t password_len,
143			      const char *identifier);
144struct crypto_ec_point *
145sae_derive_pwe_from_pt_ecc(const struct sae_pt *pt,
146			   const u8 *addr1, const u8 *addr2);
147struct crypto_bignum *
148sae_derive_pwe_from_pt_ffc(const struct sae_pt *pt,
149			   const u8 *addr1, const u8 *addr2);
150void sae_deinit_pt(struct sae_pt *pt);
151
152/* sae_pk.c */
153#ifdef CONFIG_SAE_PK
154bool sae_pk_valid_password(const char *pw);
155#else /* CONFIG_SAE_PK */
156static inline bool sae_pk_valid_password(const char *pw)
157{
158	return false;
159}
160#endif /* CONFIG_SAE_PK */
161char * sae_pk_base32_encode(const u8 *src, size_t len_bits);
162u8 * sae_pk_base32_decode(const char *src, size_t len, size_t *out_len);
163int sae_pk_set_password(struct sae_data *sae, const char *password);
164void sae_deinit_pk(struct sae_pk *pk);
165struct sae_pk * sae_parse_pk(const char *val);
166int sae_write_confirm_pk(struct sae_data *sae, struct wpabuf *buf);
167int sae_check_confirm_pk(struct sae_data *sae, const u8 *ies, size_t ies_len);
168int sae_hash(size_t hash_len, const u8 *data, size_t len, u8 *hash);
169u32 sae_pk_get_be19(const u8 *buf);
170void sae_pk_buf_shift_left_19(u8 *buf, size_t len);
171
172#endif /* SAE_H */
173