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      1 /*
      2  * hostapd / EAP Authenticator state machine internal structures (RFC 4137)
      3  * Copyright (c) 2004-2007, 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 "eap_server/eap.h"
     14 #include "eap_common/eap_common.h"
     15 
     16 /* RFC 4137 - EAP Standalone Authenticator */
     17 
     18 /**
     19  * struct eap_method - EAP method interface
     20  * This structure defines the EAP method interface. Each method will need to
     21  * register its own EAP type, EAP name, and set of function pointers for method
     22  * specific operations. This interface is based on section 5.4 of RFC 4137.
     23  */
     24 struct eap_method {
     25 	int vendor;
     26 	enum eap_type method;
     27 	const char *name;
     28 
     29 	void * (*init)(struct eap_sm *sm);
     30 	void * (*initPickUp)(struct eap_sm *sm);
     31 	void (*reset)(struct eap_sm *sm, void *priv);
     32 
     33 	struct wpabuf * (*buildReq)(struct eap_sm *sm, void *priv, u8 id);
     34 	int (*getTimeout)(struct eap_sm *sm, void *priv);
     35 	bool (*check)(struct eap_sm *sm, void *priv, struct wpabuf *respData);
     36 	void (*process)(struct eap_sm *sm, void *priv,
     37 			struct wpabuf *respData);
     38 	bool (*isDone)(struct eap_sm *sm, void *priv);
     39 	u8 * (*getKey)(struct eap_sm *sm, void *priv, size_t *len);
     40 	/* isSuccess is not specified in draft-ietf-eap-statemachine-05.txt,
     41 	 * but it is useful in implementing Policy.getDecision() */
     42 	bool (*isSuccess)(struct eap_sm *sm, void *priv);
     43 
     44 	/**
     45 	 * free - Free EAP method data
     46 	 * @method: Pointer to the method data registered with
     47 	 * eap_server_method_register().
     48 	 *
     49 	 * This function will be called when the EAP method is being
     50 	 * unregistered. If the EAP method allocated resources during
     51 	 * registration (e.g., allocated struct eap_method), they should be
     52 	 * freed in this function. No other method functions will be called
     53 	 * after this call. If this function is not defined (i.e., function
     54 	 * pointer is %NULL), a default handler is used to release the method
     55 	 * data with free(method). This is suitable for most cases.
     56 	 */
     57 	void (*free)(struct eap_method *method);
     58 
     59 #define EAP_SERVER_METHOD_INTERFACE_VERSION 1
     60 	/**
     61 	 * version - Version of the EAP server method interface
     62 	 *
     63 	 * The EAP server method implementation should set this variable to
     64 	 * EAP_SERVER_METHOD_INTERFACE_VERSION. This is used to verify that the
     65 	 * EAP method is using supported API version when using dynamically
     66 	 * loadable EAP methods.
     67 	 */
     68 	int version;
     69 
     70 	/**
     71 	 * next - Pointer to the next EAP method
     72 	 *
     73 	 * This variable is used internally in the EAP method registration code
     74 	 * to create a linked list of registered EAP methods.
     75 	 */
     76 	struct eap_method *next;
     77 
     78 	/**
     79 	 * get_emsk - Get EAP method specific keying extended material (EMSK)
     80 	 * @sm: Pointer to EAP state machine allocated with eap_sm_init()
     81 	 * @priv: Pointer to private EAP method data from eap_method::init()
     82 	 * @len: Pointer to a variable to store EMSK length
     83 	 * Returns: EMSK or %NULL if not available
     84 	 *
     85 	 * This function can be used to get the extended keying material from
     86 	 * the EAP method. The key may already be stored in the method-specific
     87 	 * private data or this function may derive the key.
     88 	 */
     89 	u8 * (*get_emsk)(struct eap_sm *sm, void *priv, size_t *len);
     90 
     91 	/**
     92 	 * getSessionId - Get EAP method specific Session-Id
     93 	 * @sm: Pointer to EAP state machine allocated with eap_server_sm_init()
     94 	 * @priv: Pointer to private EAP method data from eap_method::init()
     95 	 * @len: Pointer to a variable to store Session-Id length
     96 	 * Returns: Session-Id or %NULL if not available
     97 	 *
     98 	 * This function can be used to get the Session-Id from the EAP method.
     99 	 * The Session-Id may already be stored in the method-specific private
    100 	 * data or this function may derive the Session-Id.
    101 	 */
    102 	u8 * (*getSessionId)(struct eap_sm *sm, void *priv, size_t *len);
    103 };
    104 
    105 /**
    106  * struct eap_sm - EAP server state machine data
    107  */
    108 struct eap_sm {
    109 	enum {
    110 		EAP_DISABLED, EAP_INITIALIZE, EAP_IDLE, EAP_RECEIVED,
    111 		EAP_INTEGRITY_CHECK, EAP_METHOD_RESPONSE, EAP_METHOD_REQUEST,
    112 		EAP_PROPOSE_METHOD, EAP_SELECT_ACTION, EAP_SEND_REQUEST,
    113 		EAP_DISCARD, EAP_NAK, EAP_RETRANSMIT, EAP_SUCCESS, EAP_FAILURE,
    114 		EAP_TIMEOUT_FAILURE, EAP_PICK_UP_METHOD,
    115 		EAP_INITIALIZE_PASSTHROUGH, EAP_IDLE2, EAP_RETRANSMIT2,
    116 		EAP_RECEIVED2, EAP_DISCARD2, EAP_SEND_REQUEST2,
    117 		EAP_AAA_REQUEST, EAP_AAA_RESPONSE, EAP_AAA_IDLE,
    118 		EAP_TIMEOUT_FAILURE2, EAP_FAILURE2, EAP_SUCCESS2,
    119 		EAP_INITIATE_REAUTH_START, EAP_INITIATE_RECEIVED
    120 	} EAP_state;
    121 
    122 	/* Constants */
    123 	int MaxRetrans;
    124 
    125 	struct eap_eapol_interface eap_if;
    126 
    127 	/* Full authenticator state machine local variables */
    128 
    129 	/* Long-term (maintained between packets) */
    130 	enum eap_type currentMethod;
    131 	int currentId;
    132 	enum {
    133 		METHOD_PROPOSED, METHOD_CONTINUE, METHOD_END
    134 	} methodState;
    135 	int retransCount;
    136 	struct wpabuf *lastReqData;
    137 	int methodTimeout;
    138 
    139 	/* Short-term (not maintained between packets) */
    140 	bool rxResp;
    141 	bool rxInitiate;
    142 	int respId;
    143 	enum eap_type respMethod;
    144 	int respVendor;
    145 	u32 respVendorMethod;
    146 	bool ignore;
    147 	enum {
    148 		DECISION_SUCCESS, DECISION_FAILURE, DECISION_CONTINUE,
    149 		DECISION_PASSTHROUGH, DECISION_INITIATE_REAUTH_START
    150 	} decision;
    151 
    152 	/* Miscellaneous variables */
    153 	const struct eap_method *m; /* selected EAP method */
    154 	/* not defined in RFC 4137 */
    155 	bool changed;
    156 	void *eapol_ctx;
    157 	const struct eapol_callbacks *eapol_cb;
    158 	void *eap_method_priv;
    159 	u8 *identity;
    160 	size_t identity_len;
    161 	char *serial_num;
    162 	char imsi[20];
    163 	char sim_aka_permanent[20];
    164 	/* Whether Phase 2 method should validate identity match */
    165 	int require_identity_match;
    166 	int lastId; /* Identifier used in the last EAP-Packet */
    167 	struct eap_user *user;
    168 	int user_eap_method_index;
    169 	int init_phase2;
    170 	const struct eap_config *cfg;
    171 	struct eap_config cfg_buf;
    172 	bool update_user;
    173 
    174 	unsigned int num_rounds;
    175 	unsigned int num_rounds_short;
    176 	enum {
    177 		METHOD_PENDING_NONE, METHOD_PENDING_WAIT, METHOD_PENDING_CONT
    178 	} method_pending;
    179 
    180 	/* Optional challenges generated in Phase 1 (EAP-FAST) */
    181 	u8 *auth_challenge;
    182 	u8 *peer_challenge;
    183 
    184 	/* Whether to use the EAP-FAST-MSCHAPv2 instantiation of EAP-MSCHAPv2.
    185 	 * That variant is otherwise identical, but it generates the MSK using
    186 	 * MS-MPPE keys in reverse order. */
    187 	bool eap_fast_mschapv2;
    188 
    189 	struct wpabuf *assoc_wps_ie;
    190 	struct wpabuf *assoc_p2p_ie;
    191 
    192 	bool start_reauth;
    193 
    194 	u8 peer_addr[ETH_ALEN];
    195 
    196 	bool initiate_reauth_start_sent;
    197 	bool try_initiate_reauth;
    198 
    199 #ifdef CONFIG_TESTING_OPTIONS
    200 	u32 tls_test_flags;
    201 #endif /* CONFIG_TESTING_OPTIONS */
    202 };
    203 
    204 int eap_user_get(struct eap_sm *sm, const u8 *identity, size_t identity_len,
    205 		 int phase2);
    206 void eap_log_msg(struct eap_sm *sm, const char *fmt, ...)
    207 PRINTF_FORMAT(2, 3);
    208 void eap_sm_process_nak(struct eap_sm *sm, const u8 *nak_list, size_t len);
    209 
    210 #endif /* EAP_I_H */
    211