1  /*
2   * EAP peer/server: EAP-SIM/AKA/AKA' shared routines
3   * Copyright (c) 2004-2008, 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 EAP_SIM_COMMON_H
10  #define EAP_SIM_COMMON_H
11  
12  #define EAP_SIM_NONCE_S_LEN 16
13  #define EAP_SIM_NONCE_MT_LEN 16
14  #define EAP_SIM_MAC_LEN 16
15  #define EAP_SIM_MK_LEN 20
16  #define EAP_SIM_K_AUT_LEN 16
17  #define EAP_SIM_K_ENCR_LEN 16
18  #define EAP_SIM_KEYING_DATA_LEN 64
19  #define EAP_SIM_IV_LEN 16
20  #define EAP_SIM_KC_LEN 8
21  #define EAP_SIM_SRES_LEN 4
22  
23  #define GSM_RAND_LEN 16
24  
25  #define EAP_SIM_VERSION 1
26  
27  /* EAP-SIM Subtypes */
28  #define EAP_SIM_SUBTYPE_START 10
29  #define EAP_SIM_SUBTYPE_CHALLENGE 11
30  #define EAP_SIM_SUBTYPE_NOTIFICATION 12
31  #define EAP_SIM_SUBTYPE_REAUTHENTICATION 13
32  #define EAP_SIM_SUBTYPE_CLIENT_ERROR 14
33  
34  /* AT_CLIENT_ERROR_CODE error codes */
35  #define EAP_SIM_UNABLE_TO_PROCESS_PACKET 0
36  #define EAP_SIM_UNSUPPORTED_VERSION 1
37  #define EAP_SIM_INSUFFICIENT_NUM_OF_CHAL 2
38  #define EAP_SIM_RAND_NOT_FRESH 3
39  
40  #define EAP_SIM_MAX_FAST_REAUTHS 1000
41  
42  #define EAP_SIM_MAX_CHAL 3
43  
44  
45  /* EAP-AKA Subtypes */
46  #define EAP_AKA_SUBTYPE_CHALLENGE 1
47  #define EAP_AKA_SUBTYPE_AUTHENTICATION_REJECT 2
48  #define EAP_AKA_SUBTYPE_SYNCHRONIZATION_FAILURE 4
49  #define EAP_AKA_SUBTYPE_IDENTITY 5
50  #define EAP_AKA_SUBTYPE_NOTIFICATION 12
51  #define EAP_AKA_SUBTYPE_REAUTHENTICATION 13
52  #define EAP_AKA_SUBTYPE_CLIENT_ERROR 14
53  
54  /* AT_CLIENT_ERROR_CODE error codes */
55  #define EAP_AKA_UNABLE_TO_PROCESS_PACKET 0
56  
57  #define EAP_AKA_RAND_LEN 16
58  #define EAP_AKA_AUTN_LEN 16
59  #define EAP_AKA_AUTS_LEN 14
60  #define EAP_AKA_RES_MAX_LEN 16
61  #define EAP_AKA_IK_LEN 16
62  #define EAP_AKA_CK_LEN 16
63  #define EAP_AKA_MAX_FAST_REAUTHS 1000
64  #define EAP_AKA_MIN_RES_LEN 4
65  #define EAP_AKA_MAX_RES_LEN 16
66  #define EAP_AKA_CHECKCODE_LEN 20
67  
68  #define EAP_AKA_PRIME_K_AUT_LEN 32
69  #define EAP_AKA_PRIME_CHECKCODE_LEN 32
70  #define EAP_AKA_PRIME_K_RE_LEN 32
71  
72  struct wpabuf;
73  
74  void eap_sim_derive_mk(const u8 *identity, size_t identity_len,
75  		       const u8 *nonce_mt, u16 selected_version,
76  		       const u8 *ver_list, size_t ver_list_len,
77  		       int num_chal, const u8 *kc, u8 *mk);
78  void eap_aka_derive_mk(const u8 *identity, size_t identity_len,
79  		       const u8 *ik, const u8 *ck, u8 *mk);
80  int eap_sim_derive_keys(const u8 *mk, u8 *k_encr, u8 *k_aut, u8 *msk,
81  			u8 *emsk);
82  int eap_sim_derive_keys_reauth(u16 _counter,
83  			       const u8 *identity, size_t identity_len,
84  			       const u8 *nonce_s, const u8 *mk, u8 *msk,
85  			       u8 *emsk);
86  int eap_sim_verify_mac(const u8 *k_aut, const struct wpabuf *req,
87  		       const u8 *mac, const u8 *extra, size_t extra_len);
88  void eap_sim_add_mac(const u8 *k_aut, const u8 *msg, size_t msg_len, u8 *mac,
89  		     const u8 *extra, size_t extra_len);
90  
91  #if defined(EAP_AKA_PRIME) || defined(EAP_SERVER_AKA_PRIME)
92  void eap_aka_prime_derive_keys(const u8 *identity, size_t identity_len,
93  			       const u8 *ik, const u8 *ck, u8 *k_encr,
94  			       u8 *k_aut, u8 *k_re, u8 *msk, u8 *emsk);
95  int eap_aka_prime_derive_keys_reauth(const u8 *k_re, u16 counter,
96  				     const u8 *identity, size_t identity_len,
97  				     const u8 *nonce_s, u8 *msk, u8 *emsk);
98  int eap_sim_verify_mac_sha256(const u8 *k_aut, const struct wpabuf *req,
99  			      const u8 *mac, const u8 *extra,
100  			      size_t extra_len);
101  void eap_sim_add_mac_sha256(const u8 *k_aut, const u8 *msg, size_t msg_len,
102  			    u8 *mac, const u8 *extra, size_t extra_len);
103  
104  void eap_aka_prime_derive_ck_ik_prime(u8 *ck, u8 *ik, const u8 *sqn_ak,
105  				      const u8 *network_name,
106  				      size_t network_name_len);
107  #else /* EAP_AKA_PRIME || EAP_SERVER_AKA_PRIME */
eap_aka_prime_derive_keys(const u8 * identity,size_t identity_len,const u8 * ik,const u8 * ck,u8 * k_encr,u8 * k_aut,u8 * k_re,u8 * msk,u8 * emsk)108  static inline void eap_aka_prime_derive_keys(const u8 *identity,
109  					     size_t identity_len,
110  					     const u8 *ik, const u8 *ck,
111  					     u8 *k_encr, u8 *k_aut, u8 *k_re,
112  					     u8 *msk, u8 *emsk)
113  {
114  }
115  
eap_aka_prime_derive_keys_reauth(const u8 * k_re,u16 counter,const u8 * identity,size_t identity_len,const u8 * nonce_s,u8 * msk,u8 * emsk)116  static inline int eap_aka_prime_derive_keys_reauth(const u8 *k_re, u16 counter,
117  						   const u8 *identity,
118  						   size_t identity_len,
119  						   const u8 *nonce_s, u8 *msk,
120  						   u8 *emsk)
121  {
122  	return -1;
123  }
124  
eap_sim_verify_mac_sha256(const u8 * k_aut,const struct wpabuf * req,const u8 * mac,const u8 * extra,size_t extra_len)125  static inline int eap_sim_verify_mac_sha256(const u8 *k_aut,
126  					    const struct wpabuf *req,
127  					    const u8 *mac, const u8 *extra,
128  					    size_t extra_len)
129  {
130  	return -1;
131  }
132  #endif /* EAP_AKA_PRIME || EAP_SERVER_AKA_PRIME */
133  
134  
135  /* EAP-SIM/AKA Attributes (0..127 non-skippable) */
136  #define EAP_SIM_AT_RAND 1
137  #define EAP_SIM_AT_AUTN 2 /* only AKA */
138  #define EAP_SIM_AT_RES 3 /* only AKA, only peer->server */
139  #define EAP_SIM_AT_AUTS 4 /* only AKA, only peer->server */
140  #define EAP_SIM_AT_PADDING 6 /* only encrypted */
141  #define EAP_SIM_AT_NONCE_MT 7 /* only SIM, only send */
142  #define EAP_SIM_AT_PERMANENT_ID_REQ 10
143  #define EAP_SIM_AT_MAC 11
144  #define EAP_SIM_AT_NOTIFICATION 12
145  #define EAP_SIM_AT_ANY_ID_REQ 13
146  #define EAP_SIM_AT_IDENTITY 14 /* only send */
147  #define EAP_SIM_AT_VERSION_LIST 15 /* only SIM */
148  #define EAP_SIM_AT_SELECTED_VERSION 16 /* only SIM */
149  #define EAP_SIM_AT_FULLAUTH_ID_REQ 17
150  #define EAP_SIM_AT_COUNTER 19 /* only encrypted */
151  #define EAP_SIM_AT_COUNTER_TOO_SMALL 20 /* only encrypted */
152  #define EAP_SIM_AT_NONCE_S 21 /* only encrypted */
153  #define EAP_SIM_AT_CLIENT_ERROR_CODE 22 /* only send */
154  #define EAP_SIM_AT_KDF_INPUT 23 /* only AKA' */
155  #define EAP_SIM_AT_KDF 24 /* only AKA' */
156  #define EAP_SIM_AT_IV 129
157  #define EAP_SIM_AT_ENCR_DATA 130
158  #define EAP_SIM_AT_NEXT_PSEUDONYM 132 /* only encrypted */
159  #define EAP_SIM_AT_NEXT_REAUTH_ID 133 /* only encrypted */
160  #define EAP_SIM_AT_CHECKCODE 134 /* only AKA */
161  #define EAP_SIM_AT_RESULT_IND 135
162  #define EAP_SIM_AT_BIDDING 136
163  
164  /* AT_NOTIFICATION notification code values */
165  #define EAP_SIM_GENERAL_FAILURE_AFTER_AUTH 0
166  #define EAP_SIM_TEMPORARILY_DENIED 1026
167  #define EAP_SIM_NOT_SUBSCRIBED 1031
168  #define EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH 16384
169  #define EAP_SIM_SUCCESS 32768
170  
171  /* EAP-AKA' AT_KDF Key Derivation Function values */
172  #define EAP_AKA_PRIME_KDF 1
173  
174  /* AT_BIDDING flags */
175  #define EAP_AKA_BIDDING_FLAG_D 0x8000
176  
177  
178  enum eap_sim_id_req {
179  	NO_ID_REQ, ANY_ID, FULLAUTH_ID, PERMANENT_ID
180  };
181  
182  
183  struct eap_sim_attrs {
184  	const u8 *rand, *autn, *mac, *iv, *encr_data, *version_list, *nonce_s;
185  	const u8 *next_pseudonym, *next_reauth_id;
186  	const u8 *nonce_mt, *identity, *res, *auts;
187  	const u8 *checkcode;
188  	const u8 *kdf_input;
189  	const u8 *bidding;
190  	size_t num_chal, version_list_len, encr_data_len;
191  	size_t next_pseudonym_len, next_reauth_id_len, identity_len, res_len;
192  	size_t res_len_bits;
193  	size_t checkcode_len;
194  	size_t kdf_input_len;
195  	enum eap_sim_id_req id_req;
196  	int notification, counter, selected_version, client_error_code;
197  	int counter_too_small;
198  	int result_ind;
199  #define EAP_AKA_PRIME_KDF_MAX 10
200  	u16 kdf[EAP_AKA_PRIME_KDF_MAX];
201  	size_t kdf_count;
202  };
203  
204  int eap_sim_parse_attr(const u8 *start, const u8 *end,
205  		       struct eap_sim_attrs *attr, int aka, int encr);
206  u8 * eap_sim_parse_encr(const u8 *k_encr, const u8 *encr_data,
207  			size_t encr_data_len, const u8 *iv,
208  			struct eap_sim_attrs *attr, int aka);
209  
210  
211  struct eap_sim_msg;
212  
213  struct eap_sim_msg * eap_sim_msg_init(int code, int id, int type, int subtype);
214  struct wpabuf * eap_sim_msg_finish(struct eap_sim_msg *msg, int type,
215  				   const u8 *k_aut,
216  				   const u8 *extra, size_t extra_len);
217  void eap_sim_msg_free(struct eap_sim_msg *msg);
218  u8 * eap_sim_msg_add_full(struct eap_sim_msg *msg, u8 attr,
219  			  const u8 *data, size_t len);
220  u8 * eap_sim_msg_add(struct eap_sim_msg *msg, u8 attr,
221  		     u16 value, const u8 *data, size_t len);
222  u8 * eap_sim_msg_add_mac(struct eap_sim_msg *msg, u8 attr);
223  int eap_sim_msg_add_encr_start(struct eap_sim_msg *msg, u8 attr_iv,
224  			       u8 attr_encr);
225  int eap_sim_msg_add_encr_end(struct eap_sim_msg *msg, u8 *k_encr,
226  			     int attr_pad);
227  
228  void eap_sim_report_notification(void *msg_ctx, int notification, int aka);
229  int eap_sim_anonymous_username(const u8 *id, size_t id_len);
230  
231  #endif /* EAP_SIM_COMMON_H */
232