Home | History | Annotate | Download | only in eap_peer
      1 /*
      2  * EAP peer state machines internal structures (RFC 4137)
      3  * Copyright (c) 2004-2014, Jouni Malinen <j (at) 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_I_H
     10 #define EAP_I_H
     11 
     12 #include "wpabuf.h"
     13 #include "utils/list.h"
     14 #include "eap_peer/eap.h"
     15 #include "eap_common/eap_common.h"
     16 
     17 #define NO_EAP_METHOD_ERROR (-1)
     18 
     19 /* RFC 4137 - EAP Peer state machine */
     20 
     21 typedef enum {
     22 	DECISION_FAIL, DECISION_COND_SUCC, DECISION_UNCOND_SUCC
     23 } EapDecision;
     24 
     25 typedef enum {
     26 	METHOD_NONE, METHOD_INIT, METHOD_CONT, METHOD_MAY_CONT, METHOD_DONE
     27 } EapMethodState;
     28 
     29 /**
     30  * struct eap_method_ret - EAP return values from struct eap_method::process()
     31  *
     32  * These structure contains OUT variables for the interface between peer state
     33  * machine and methods (RFC 4137, Sect. 4.2). eapRespData will be returned as
     34  * the return value of struct eap_method::process() so it is not included in
     35  * this structure.
     36  */
     37 struct eap_method_ret {
     38 	/**
     39 	 * ignore - Whether method decided to drop the current packed (OUT)
     40 	 */
     41 	Boolean ignore;
     42 
     43 	/**
     44 	 * methodState - Method-specific state (IN/OUT)
     45 	 */
     46 	EapMethodState methodState;
     47 
     48 	/**
     49 	 * decision - Authentication decision (OUT)
     50 	 */
     51 	EapDecision decision;
     52 
     53 	/**
     54 	 * allowNotifications - Whether method allows notifications (OUT)
     55 	 */
     56 	Boolean allowNotifications;
     57 };
     58 
     59 
     60 /**
     61  * struct eap_method - EAP method interface
     62  * This structure defines the EAP method interface. Each method will need to
     63  * register its own EAP type, EAP name, and set of function pointers for method
     64  * specific operations. This interface is based on section 4.4 of RFC 4137.
     65  */
     66 struct eap_method {
     67 	/**
     68 	 * vendor - EAP Vendor-ID (EAP_VENDOR_*) (0 = IETF)
     69 	 */
     70 	int vendor;
     71 
     72 	/**
     73 	 * method - EAP type number (EAP_TYPE_*)
     74 	 */
     75 	EapType method;
     76 
     77 	/**
     78 	 * name - Name of the method (e.g., "TLS")
     79 	 */
     80 	const char *name;
     81 
     82 	/**
     83 	 * init - Initialize an EAP method
     84 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
     85 	 * Returns: Pointer to allocated private data, or %NULL on failure
     86 	 *
     87 	 * This function is used to initialize the EAP method explicitly
     88 	 * instead of using METHOD_INIT state as specific in RFC 4137. The
     89 	 * method is expected to initialize it method-specific state and return
     90 	 * a pointer that will be used as the priv argument to other calls.
     91 	 */
     92 	void * (*init)(struct eap_sm *sm);
     93 
     94 	/**
     95 	 * deinit - Deinitialize an EAP method
     96 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
     97 	 * @priv: Pointer to private EAP method data from eap_method::init()
     98 	 *
     99 	 * Deinitialize the EAP method and free any allocated private data.
    100 	 */
    101 	void (*deinit)(struct eap_sm *sm, void *priv);
    102 
    103 	/**
    104 	 * process - Process an EAP request
    105 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    106 	 * @priv: Pointer to private EAP method data from eap_method::init()
    107 	 * @ret: Return values from EAP request validation and processing
    108 	 * @reqData: EAP request to be processed (eapReqData)
    109 	 * Returns: Pointer to allocated EAP response packet (eapRespData)
    110 	 *
    111 	 * This function is a combination of m.check(), m.process(), and
    112 	 * m.buildResp() procedures defined in section 4.4 of RFC 4137 In other
    113 	 * words, this function validates the incoming request, processes it,
    114 	 * and build a response packet. m.check() and m.process() return values
    115 	 * are returned through struct eap_method_ret *ret variable. Caller is
    116 	 * responsible for freeing the returned EAP response packet.
    117 	 */
    118 	struct wpabuf * (*process)(struct eap_sm *sm, void *priv,
    119 				   struct eap_method_ret *ret,
    120 				   const struct wpabuf *reqData);
    121 
    122 	/**
    123 	 * isKeyAvailable - Find out whether EAP method has keying material
    124 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    125 	 * @priv: Pointer to private EAP method data from eap_method::init()
    126 	 * Returns: %TRUE if key material (eapKeyData) is available
    127 	 */
    128 	Boolean (*isKeyAvailable)(struct eap_sm *sm, void *priv);
    129 
    130 	/**
    131 	 * getKey - Get EAP method specific keying material (eapKeyData)
    132 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    133 	 * @priv: Pointer to private EAP method data from eap_method::init()
    134 	 * @len: Pointer to variable to store key length (eapKeyDataLen)
    135 	 * Returns: Keying material (eapKeyData) or %NULL if not available
    136 	 *
    137 	 * This function can be used to get the keying material from the EAP
    138 	 * method. The key may already be stored in the method-specific private
    139 	 * data or this function may derive the key.
    140 	 */
    141 	u8 * (*getKey)(struct eap_sm *sm, void *priv, size_t *len);
    142 
    143 	/**
    144 	 * get_status - Get EAP method status
    145 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    146 	 * @priv: Pointer to private EAP method data from eap_method::init()
    147 	 * @buf: Buffer for status information
    148 	 * @buflen: Maximum buffer length
    149 	 * @verbose: Whether to include verbose status information
    150 	 * Returns: Number of bytes written to buf
    151 	 *
    152 	 * Query EAP method for status information. This function fills in a
    153 	 * text area with current status information from the EAP method. If
    154 	 * the buffer (buf) is not large enough, status information will be
    155 	 * truncated to fit the buffer.
    156 	 */
    157 	int (*get_status)(struct eap_sm *sm, void *priv, char *buf,
    158 			  size_t buflen, int verbose);
    159 
    160 	/**
    161 	 * has_reauth_data - Whether method is ready for fast reauthentication
    162 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    163 	 * @priv: Pointer to private EAP method data from eap_method::init()
    164 	 * Returns: %TRUE or %FALSE based on whether fast reauthentication is
    165 	 * possible
    166 	 *
    167 	 * This function is an optional handler that only EAP methods
    168 	 * supporting fast re-authentication need to implement.
    169 	 */
    170 	Boolean (*has_reauth_data)(struct eap_sm *sm, void *priv);
    171 
    172 	/**
    173 	 * deinit_for_reauth - Release data that is not needed for fast re-auth
    174 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    175 	 * @priv: Pointer to private EAP method data from eap_method::init()
    176 	 *
    177 	 * This function is an optional handler that only EAP methods
    178 	 * supporting fast re-authentication need to implement. This is called
    179 	 * when authentication has been completed and EAP state machine is
    180 	 * requesting that enough state information is maintained for fast
    181 	 * re-authentication
    182 	 */
    183 	void (*deinit_for_reauth)(struct eap_sm *sm, void *priv);
    184 
    185 	/**
    186 	 * init_for_reauth - Prepare for start of fast re-authentication
    187 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    188 	 * @priv: Pointer to private EAP method data from eap_method::init()
    189 	 *
    190 	 * This function is an optional handler that only EAP methods
    191 	 * supporting fast re-authentication need to implement. This is called
    192 	 * when EAP authentication is started and EAP state machine is
    193 	 * requesting fast re-authentication to be used.
    194 	 */
    195 	void * (*init_for_reauth)(struct eap_sm *sm, void *priv);
    196 
    197 	/**
    198 	 * get_identity - Get method specific identity for re-authentication
    199 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    200 	 * @priv: Pointer to private EAP method data from eap_method::init()
    201 	 * @len: Length of the returned identity
    202 	 * Returns: Pointer to the method specific identity or %NULL if default
    203 	 * identity is to be used
    204 	 *
    205 	 * This function is an optional handler that only EAP methods
    206 	 * that use method specific identity need to implement.
    207 	 */
    208 	const u8 * (*get_identity)(struct eap_sm *sm, void *priv, size_t *len);
    209 
    210 	/**
    211 	 * get_error_code - Get latest EAP method error code
    212 	 * @priv: Pointer to private EAP method data from eap_method::init()
    213 	 * Returns: An int for the EAP Method Error code if exists or
    214 	 * NO_EAP_METHOD_ERROR otherwise
    215 	 *
    216 	 * This method is an optional handler that only EAP methods that need to
    217 	 * report their error code need to implement.
    218 	 */
    219 	int (*get_error_code)(void *priv);
    220 
    221 	/**
    222 	 * free - Free EAP method data
    223 	 * @method: Pointer to the method data registered with
    224 	 * eap_peer_method_register().
    225 	 *
    226 	 * This function will be called when the EAP method is being
    227 	 * unregistered. If the EAP method allocated resources during
    228 	 * registration (e.g., allocated struct eap_method), they should be
    229 	 * freed in this function. No other method functions will be called
    230 	 * after this call. If this function is not defined (i.e., function
    231 	 * pointer is %NULL), a default handler is used to release the method
    232 	 * data with free(method). This is suitable for most cases.
    233 	 */
    234 	void (*free)(struct eap_method *method);
    235 
    236 #define EAP_PEER_METHOD_INTERFACE_VERSION 1
    237 	/**
    238 	 * version - Version of the EAP peer method interface
    239 	 *
    240 	 * The EAP peer method implementation should set this variable to
    241 	 * EAP_PEER_METHOD_INTERFACE_VERSION. This is used to verify that the
    242 	 * EAP method is using supported API version when using dynamically
    243 	 * loadable EAP methods.
    244 	 */
    245 	int version;
    246 
    247 	/**
    248 	 * next - Pointer to the next EAP method
    249 	 *
    250 	 * This variable is used internally in the EAP method registration code
    251 	 * to create a linked list of registered EAP methods.
    252 	 */
    253 	struct eap_method *next;
    254 
    255 #ifdef CONFIG_DYNAMIC_EAP_METHODS
    256 	/**
    257 	 * dl_handle - Handle for the dynamic library
    258 	 *
    259 	 * This variable is used internally in the EAP method registration code
    260 	 * to store a handle for the dynamic library. If the method is linked
    261 	 * in statically, this is %NULL.
    262 	 */
    263 	void *dl_handle;
    264 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
    265 
    266 	/**
    267 	 * get_emsk - Get EAP method specific keying extended material (EMSK)
    268 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    269 	 * @priv: Pointer to private EAP method data from eap_method::init()
    270 	 * @len: Pointer to a variable to store EMSK length
    271 	 * Returns: EMSK or %NULL if not available
    272 	 *
    273 	 * This function can be used to get the extended keying material from
    274 	 * the EAP method. The key may already be stored in the method-specific
    275 	 * private data or this function may derive the key.
    276 	 */
    277 	u8 * (*get_emsk)(struct eap_sm *sm, void *priv, size_t *len);
    278 
    279 	/**
    280 	 * getSessionId - Get EAP method specific Session-Id
    281 	 * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    282 	 * @priv: Pointer to private EAP method data from eap_method::init()
    283 	 * @len: Pointer to a variable to store Session-Id length
    284 	 * Returns: Session-Id or %NULL if not available
    285 	 *
    286 	 * This function can be used to get the Session-Id from the EAP method.
    287 	 * The Session-Id may already be stored in the method-specific private
    288 	 * data or this function may derive the Session-Id.
    289 	 */
    290 	u8 * (*getSessionId)(struct eap_sm *sm, void *priv, size_t *len);
    291 };
    292 
    293 
    294 struct eap_erp_key {
    295 	struct dl_list list;
    296 	size_t rRK_len;
    297 	size_t rIK_len;
    298 	u8 rRK[ERP_MAX_KEY_LEN];
    299 	u8 rIK[ERP_MAX_KEY_LEN];
    300 	u32 next_seq;
    301 	char keyname_nai[];
    302 };
    303 
    304 /**
    305  * struct eap_sm - EAP state machine data
    306  */
    307 struct eap_sm {
    308 	enum {
    309 		EAP_INITIALIZE, EAP_DISABLED, EAP_IDLE, EAP_RECEIVED,
    310 		EAP_GET_METHOD, EAP_METHOD, EAP_SEND_RESPONSE, EAP_DISCARD,
    311 		EAP_IDENTITY, EAP_NOTIFICATION, EAP_RETRANSMIT, EAP_SUCCESS,
    312 		EAP_FAILURE
    313 	} EAP_state;
    314 	/* Long-term local variables */
    315 	EapType selectedMethod;
    316 	EapMethodState methodState;
    317 	int lastId;
    318 	struct wpabuf *lastRespData;
    319 	EapDecision decision;
    320 	/* Short-term local variables */
    321 	Boolean rxReq;
    322 	Boolean rxSuccess;
    323 	Boolean rxFailure;
    324 	int reqId;
    325 	EapType reqMethod;
    326 	int reqVendor;
    327 	u32 reqVendorMethod;
    328 	Boolean ignore;
    329 	/* Constants */
    330 	int ClientTimeout;
    331 
    332 	/* Miscellaneous variables */
    333 	Boolean allowNotifications; /* peer state machine <-> methods */
    334 	struct wpabuf *eapRespData; /* peer to lower layer */
    335 	Boolean eapKeyAvailable; /* peer to lower layer */
    336 	u8 *eapKeyData; /* peer to lower layer */
    337 	size_t eapKeyDataLen; /* peer to lower layer */
    338 	u8 *eapSessionId; /* peer to lower layer */
    339 	size_t eapSessionIdLen; /* peer to lower layer */
    340 	const struct eap_method *m; /* selected EAP method */
    341 	/* not defined in RFC 4137 */
    342 	Boolean changed;
    343 	void *eapol_ctx;
    344 	const struct eapol_callbacks *eapol_cb;
    345 	void *eap_method_priv;
    346 	int init_phase2;
    347 	int fast_reauth;
    348 	Boolean reauthInit; /* send EAP-Identity/Re-auth */
    349 	u32 erp_seq;
    350 
    351 	Boolean rxResp /* LEAP only */;
    352 	Boolean leap_done;
    353 	Boolean peap_done;
    354 	u8 req_sha1[20]; /* SHA1() of the current EAP packet */
    355 	u8 last_sha1[20]; /* SHA1() of the previously received EAP packet; used
    356 			   * in duplicate request detection. */
    357 
    358 	void *msg_ctx;
    359 	void *scard_ctx;
    360 	void *ssl_ctx;
    361 	void *ssl_ctx2;
    362 
    363 	unsigned int workaround;
    364 
    365 	/* Optional challenges generated in Phase 1 (EAP-FAST) */
    366 	u8 *peer_challenge, *auth_challenge;
    367 
    368 	int num_rounds;
    369 	int force_disabled;
    370 
    371 	struct wps_context *wps;
    372 
    373 	int prev_failure;
    374 	struct eap_peer_config *last_config;
    375 
    376 	struct ext_password_data *ext_pw;
    377 	struct wpabuf *ext_pw_buf;
    378 
    379 	int external_sim;
    380 
    381 	unsigned int expected_failure:1;
    382 	unsigned int ext_cert_check:1;
    383 	unsigned int waiting_ext_cert_check:1;
    384 
    385 	struct dl_list erp_keys; /* struct eap_erp_key */
    386 };
    387 
    388 const u8 * eap_get_config_identity(struct eap_sm *sm, size_t *len);
    389 const u8 * eap_get_config_password(struct eap_sm *sm, size_t *len);
    390 const u8 * eap_get_config_password2(struct eap_sm *sm, size_t *len, int *hash);
    391 const u8 * eap_get_config_new_password(struct eap_sm *sm, size_t *len);
    392 const u8 * eap_get_config_otp(struct eap_sm *sm, size_t *len);
    393 void eap_clear_config_otp(struct eap_sm *sm);
    394 const char * eap_get_config_phase1(struct eap_sm *sm);
    395 const char * eap_get_config_phase2(struct eap_sm *sm);
    396 int eap_get_config_fragment_size(struct eap_sm *sm);
    397 struct eap_peer_config * eap_get_config(struct eap_sm *sm);
    398 void eap_set_config_blob(struct eap_sm *sm, struct wpa_config_blob *blob);
    399 const struct wpa_config_blob *
    400 eap_get_config_blob(struct eap_sm *sm, const char *name);
    401 void eap_notify_pending(struct eap_sm *sm);
    402 int eap_allowed_method(struct eap_sm *sm, int vendor, u32 method);
    403 
    404 #endif /* EAP_I_H */
    405