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_PMK_LEN_MAX 64
15 #define SAE_PMKID_LEN 16
16 #define SAE_MAX_PRIME_LEN 512
17 #define SAE_MAX_ECC_PRIME_LEN 66
18 #define SAE_MAX_HASH_LEN 64
19 #define SAE_COMMIT_MAX_LEN (2 + 3 * SAE_MAX_PRIME_LEN + 255)
20 #ifdef CONFIG_SAE_PK
21 #define SAE_CONFIRM_MAX_LEN ((2 + SAE_MAX_HASH_LEN) + 1500)
22 #else /* CONFIG_SAE_PK */
23 #define SAE_CONFIRM_MAX_LEN (2 + SAE_MAX_HASH_LEN)
24 #endif /* CONFIG_SAE_PK */
25 #define SAE_PK_M_LEN 16
26
27 /* Special value returned by sae_parse_commit() */
28 #define SAE_SILENTLY_DISCARD 65535
29
30 struct sae_pk {
31 struct wpabuf *m;
32 struct crypto_ec_key *key;
33 int group;
34 struct wpabuf *pubkey; /* DER encoded subjectPublicKey */
35 #ifdef CONFIG_TESTING_OPTIONS
36 struct crypto_ec_key *sign_key_override;
37 #endif /* CONFIG_TESTING_OPTIONS */
38 };
39
40
41 struct sae_temporary_data {
42 u8 kck[SAE_MAX_HASH_LEN];
43 size_t kck_len;
44 struct crypto_bignum *own_commit_scalar;
45 struct crypto_bignum *own_commit_element_ffc;
46 struct crypto_ec_point *own_commit_element_ecc;
47 struct crypto_bignum *peer_commit_element_ffc;
48 struct crypto_ec_point *peer_commit_element_ecc;
49 struct crypto_ec_point *pwe_ecc;
50 struct crypto_bignum *pwe_ffc;
51 struct crypto_bignum *sae_rand;
52 struct crypto_ec *ec;
53 int prime_len;
54 int order_len;
55 const struct dh_group *dh;
56 const struct crypto_bignum *prime;
57 const struct crypto_bignum *order;
58 struct crypto_bignum *prime_buf;
59 struct crypto_bignum *order_buf;
60 struct wpabuf *anti_clogging_token;
61 char *pw_id;
62 char *parsed_pw_id;
63 int vlan_id;
64 u8 bssid[ETH_ALEN];
65 struct wpabuf *own_rejected_groups;
66 struct wpabuf *peer_rejected_groups;
67 unsigned int own_addr_higher:1;
68 unsigned int try_other_password:1;
69
70 #ifdef CONFIG_SAE_PK
71 u8 kek[SAE_MAX_HASH_LEN];
72 size_t kek_len;
73 const struct sae_pk *ap_pk;
74 u8 own_addr[ETH_ALEN];
75 u8 peer_addr[ETH_ALEN];
76 u8 fingerprint[SAE_MAX_HASH_LEN];
77 size_t fingerprint_bytes;
78 size_t fingerprint_bits;
79 size_t lambda;
80 unsigned int sec;
81 u8 ssid[32];
82 size_t ssid_len;
83 #ifdef CONFIG_TESTING_OPTIONS
84 bool omit_pk_elem;
85 #endif /* CONFIG_TESTING_OPTIONS */
86 #endif /* CONFIG_SAE_PK */
87
88 struct os_reltime disabled_until;
89
90 const void *used_pw;
91 };
92
93 struct sae_pt {
94 struct sae_pt *next;
95 int group;
96 struct crypto_ec *ec;
97 struct crypto_ec_point *ecc_pt;
98
99 const struct dh_group *dh;
100 struct crypto_bignum *ffc_pt;
101 #ifdef CONFIG_SAE_PK
102 u8 ssid[32];
103 size_t ssid_len;
104 #endif /* CONFIG_SAE_PK */
105 };
106
107 enum sae_state {
108 SAE_NOTHING, SAE_COMMITTED, SAE_CONFIRMED, SAE_ACCEPTED
109 };
110
111 struct sae_data {
112 enum sae_state state;
113 u16 send_confirm;
114 u8 pmk[SAE_PMK_LEN_MAX];
115 size_t pmk_len;
116 int akmp; /* WPA_KEY_MGMT_* used in key derivation */
117 u32 own_akm_suite_selector;
118 u32 peer_akm_suite_selector;
119 u8 pmkid[SAE_PMKID_LEN];
120 struct crypto_bignum *peer_commit_scalar;
121 struct crypto_bignum *peer_commit_scalar_accepted;
122 int group;
123 unsigned int sync; /* protocol instance variable: Sync */
124 u16 rc; /* protocol instance variable: Rc (received send-confirm) */
125 unsigned int h2e:1;
126 unsigned int pk:1;
127 unsigned int no_pw_id:1;
128 struct sae_temporary_data *tmp;
129 };
130
131 int sae_set_group(struct sae_data *sae, int group);
132 void sae_clear_temp_data(struct sae_data *sae);
133 void sae_clear_data(struct sae_data *sae);
134
135 int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
136 const u8 *password, size_t password_len,
137 struct sae_data *sae);
138 int sae_prepare_commit_pt(struct sae_data *sae, const struct sae_pt *pt,
139 const u8 *addr1, const u8 *addr2,
140 int *rejected_groups, const struct sae_pk *pk);
141 int sae_process_commit(struct sae_data *sae);
142 int sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
143 const struct wpabuf *token, const char *identifier);
144 u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
145 const u8 **token, size_t *token_len, int *allowed_groups,
146 int h2e, int *ie_offset);
147 int sae_write_confirm(struct sae_data *sae, struct wpabuf *buf);
148 int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len,
149 int *ie_offset);
150 u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups, u16 group);
151 const char * sae_state_txt(enum sae_state state);
152 size_t sae_ecc_prime_len_2_hash_len(size_t prime_len);
153 size_t sae_ffc_prime_len_2_hash_len(size_t prime_len);
154 struct sae_pt * sae_derive_pt(const int *groups,
155 const u8 *ssid, size_t ssid_len,
156 const u8 *password, size_t password_len,
157 const char *identifier);
158 struct crypto_ec_point *
159 sae_derive_pwe_from_pt_ecc(const struct sae_pt *pt,
160 const u8 *addr1, const u8 *addr2);
161 struct crypto_bignum *
162 sae_derive_pwe_from_pt_ffc(const struct sae_pt *pt,
163 const u8 *addr1, const u8 *addr2);
164 void sae_deinit_pt(struct sae_pt *pt);
165
166 /* sae_pk.c */
167 #ifdef CONFIG_SAE_PK
168 bool sae_pk_valid_password(const char *pw);
169 #else /* CONFIG_SAE_PK */
sae_pk_valid_password(const char * pw)170 static inline bool sae_pk_valid_password(const char *pw)
171 {
172 return false;
173 }
174 #endif /* CONFIG_SAE_PK */
175 char * sae_pk_base32_encode(const u8 *src, size_t len_bits);
176 u8 * sae_pk_base32_decode(const char *src, size_t len, size_t *out_len);
177 int sae_pk_set_password(struct sae_data *sae, const char *password);
178 void sae_deinit_pk(struct sae_pk *pk);
179 struct sae_pk * sae_parse_pk(const char *val);
180 int sae_write_confirm_pk(struct sae_data *sae, struct wpabuf *buf);
181 int sae_check_confirm_pk(struct sae_data *sae, const u8 *ies, size_t ies_len);
182 int sae_hash(size_t hash_len, const u8 *data, size_t len, u8 *hash);
183 u32 sae_pk_get_be19(const u8 *buf);
184 void sae_pk_buf_shift_left_19(u8 *buf, size_t len);
185
186 #endif /* SAE_H */
187