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 int vlan_id;
63 u8 bssid[ETH_ALEN];
64 struct wpabuf *own_rejected_groups;
65 struct wpabuf *peer_rejected_groups;
66 unsigned int own_addr_higher:1;
67
68 #ifdef CONFIG_SAE_PK
69 u8 kek[SAE_MAX_HASH_LEN];
70 size_t kek_len;
71 const struct sae_pk *ap_pk;
72 u8 own_addr[ETH_ALEN];
73 u8 peer_addr[ETH_ALEN];
74 u8 fingerprint[SAE_MAX_HASH_LEN];
75 size_t fingerprint_bytes;
76 size_t fingerprint_bits;
77 size_t lambda;
78 unsigned int sec;
79 u8 ssid[32];
80 size_t ssid_len;
81 #ifdef CONFIG_TESTING_OPTIONS
82 bool omit_pk_elem;
83 #endif /* CONFIG_TESTING_OPTIONS */
84 #endif /* CONFIG_SAE_PK */
85 };
86
87 struct sae_pt {
88 struct sae_pt *next;
89 int group;
90 struct crypto_ec *ec;
91 struct crypto_ec_point *ecc_pt;
92
93 const struct dh_group *dh;
94 struct crypto_bignum *ffc_pt;
95 #ifdef CONFIG_SAE_PK
96 u8 ssid[32];
97 size_t ssid_len;
98 #endif /* CONFIG_SAE_PK */
99 };
100
101 enum sae_state {
102 SAE_NOTHING, SAE_COMMITTED, SAE_CONFIRMED, SAE_ACCEPTED
103 };
104
105 struct sae_data {
106 enum sae_state state;
107 u16 send_confirm;
108 u8 pmk[SAE_PMK_LEN_MAX];
109 size_t pmk_len;
110 int akmp; /* WPA_KEY_MGMT_* used in key derivation */
111 u32 own_akm_suite_selector;
112 u32 peer_akm_suite_selector;
113 u8 pmkid[SAE_PMKID_LEN];
114 struct crypto_bignum *peer_commit_scalar;
115 struct crypto_bignum *peer_commit_scalar_accepted;
116 int group;
117 unsigned int sync; /* protocol instance variable: Sync */
118 u16 rc; /* protocol instance variable: Rc (received send-confirm) */
119 unsigned int h2e:1;
120 unsigned int pk:1;
121 struct sae_temporary_data *tmp;
122 };
123
124 int sae_set_group(struct sae_data *sae, int group);
125 void sae_clear_temp_data(struct sae_data *sae);
126 void sae_clear_data(struct sae_data *sae);
127
128 int sae_prepare_commit(const u8 *addr1, const u8 *addr2,
129 const u8 *password, size_t password_len,
130 struct sae_data *sae);
131 int sae_prepare_commit_pt(struct sae_data *sae, const struct sae_pt *pt,
132 const u8 *addr1, const u8 *addr2,
133 int *rejected_groups, const struct sae_pk *pk);
134 int sae_process_commit(struct sae_data *sae);
135 int sae_write_commit(struct sae_data *sae, struct wpabuf *buf,
136 const struct wpabuf *token, const char *identifier);
137 u16 sae_parse_commit(struct sae_data *sae, const u8 *data, size_t len,
138 const u8 **token, size_t *token_len, int *allowed_groups,
139 int h2e, int *ie_offset);
140 int sae_write_confirm(struct sae_data *sae, struct wpabuf *buf);
141 int sae_check_confirm(struct sae_data *sae, const u8 *data, size_t len,
142 int *ie_offset);
143 u16 sae_group_allowed(struct sae_data *sae, int *allowed_groups, u16 group);
144 const char * sae_state_txt(enum sae_state state);
145 size_t sae_ecc_prime_len_2_hash_len(size_t prime_len);
146 size_t sae_ffc_prime_len_2_hash_len(size_t prime_len);
147 struct sae_pt * sae_derive_pt(int *groups, const u8 *ssid, size_t ssid_len,
148 const u8 *password, size_t password_len,
149 const char *identifier);
150 struct crypto_ec_point *
151 sae_derive_pwe_from_pt_ecc(const struct sae_pt *pt,
152 const u8 *addr1, const u8 *addr2);
153 struct crypto_bignum *
154 sae_derive_pwe_from_pt_ffc(const struct sae_pt *pt,
155 const u8 *addr1, const u8 *addr2);
156 void sae_deinit_pt(struct sae_pt *pt);
157
158 /* sae_pk.c */
159 #ifdef CONFIG_SAE_PK
160 bool sae_pk_valid_password(const char *pw);
161 #else /* CONFIG_SAE_PK */
sae_pk_valid_password(const char * pw)162 static inline bool sae_pk_valid_password(const char *pw)
163 {
164 return false;
165 }
166 #endif /* CONFIG_SAE_PK */
167 char * sae_pk_base32_encode(const u8 *src, size_t len_bits);
168 u8 * sae_pk_base32_decode(const char *src, size_t len, size_t *out_len);
169 int sae_pk_set_password(struct sae_data *sae, const char *password);
170 void sae_deinit_pk(struct sae_pk *pk);
171 struct sae_pk * sae_parse_pk(const char *val);
172 int sae_write_confirm_pk(struct sae_data *sae, struct wpabuf *buf);
173 int sae_check_confirm_pk(struct sae_data *sae, const u8 *ies, size_t ies_len);
174 int sae_hash(size_t hash_len, const u8 *data, size_t len, u8 *hash);
175 u32 sae_pk_get_be19(const u8 *buf);
176 void sae_pk_buf_shift_left_19(u8 *buf, size_t len);
177
178 #endif /* SAE_H */
179