added EAP-SIM authentication
[strongswan.git] / src / charon / sa / authenticators / eap / eap_method.h
1 /**
2 * @file eap_method.h
3 *
4 * @brief Interface eap_method_t.
5 *
6 */
7
8 /*
9 * Copyright (C) 2006 Martin Willi
10 * Hochschule fuer Technik Rapperswil
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms of the GNU General Public License as published by the
14 * Free Software Foundation; either version 2 of the License, or (at your
15 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
16 *
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
19 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 * for more details.
21 */
22
23 #ifndef EAP_METHOD_H_
24 #define EAP_METHOD_H_
25
26 typedef struct eap_method_t eap_method_t;
27 typedef enum eap_role_t eap_role_t;
28 typedef enum eap_type_t eap_type_t;
29 typedef enum eap_code_t eap_code_t;
30
31 #include <library.h>
32 #include <utils/identification.h>
33 #include <encoding/payloads/eap_payload.h>
34
35 /**
36 * Role of an eap_method, SERVER or PEER (client)
37 *
38 * @ingroup eap
39 */
40 enum eap_role_t {
41 EAP_SERVER,
42 EAP_PEER,
43 };
44 /**
45 * enum names for eap_role_t.
46 *
47 * @ingroup eap
48 */
49 extern enum_name_t *eap_role_names;
50
51 /**
52 * EAP types, defines the EAP method implementation
53 *
54 * @ingroup eap
55 */
56 enum eap_type_t {
57 EAP_IDENTITY = 1,
58 EAP_NOTIFICATION = 2,
59 EAP_NAK = 3,
60 EAP_MD5 = 4,
61 EAP_ONE_TIME_PASSWORD = 5,
62 EAP_TOKEN_CARD = 6,
63 EAP_SIM = 18,
64 EAP_AKA = 23,
65 };
66
67 /**
68 * enum names for eap_type_t.
69 *
70 * @ingroup eap
71 */
72 extern enum_name_t *eap_type_names;
73
74 /**
75 * EAP code, type of an EAP message
76 *
77 * @ingroup eap
78 */
79 enum eap_code_t {
80 EAP_REQUEST = 1,
81 EAP_RESPONSE = 2,
82 EAP_SUCCESS = 3,
83 EAP_FAILURE = 4,
84 };
85
86 /**
87 * enum names for eap_code_t.
88 *
89 * @ingroup eap
90 */
91 extern enum_name_t *eap_code_names;
92
93
94 /**
95 * @brief Interface of an EAP method for server and client side.
96 *
97 * An EAP method initiates an EAP exchange and processes requests and
98 * responses. An EAP method may need multiple exchanges before succeeding, and
99 * the eap_authentication may use multiple EAP methods to authenticate a peer.
100 * To accomplish these requirements, all EAP methods have their own
101 * implementation while the eap_authenticatior uses one or more of these
102 * EAP methods. Sending of EAP(SUCCESS/FAILURE) message is not the job
103 * of the method, the eap_authenticator does this.
104 * An EAP method may establish a MSK, this is used the complete the
105 * authentication. Even if a mutual EAP method is used, the traditional
106 * AUTH payloads are required. Only these include the nonces and messages from
107 * ike_sa_init and therefore prevent man in the middle attacks.
108 *
109 * @b Constructors:
110 * - eap_method_create()
111 *
112 * @ingroup eap
113 */
114 struct eap_method_t {
115
116 /**
117 * @brief Initiate the EAP exchange.
118 *
119 * initiate() is only useable for server implementations, as clients only
120 * reply to server requests.
121 * A eap_payload is created in "out" if result is NEED_MORE.
122 *
123 * @param this calling object
124 * @param out eap_payload to send to the client
125 * @return
126 * - NEED_MORE, if an other exchange is required
127 * - FAILED, if unable to create eap request payload
128 */
129 status_t (*initiate) (eap_method_t *this, eap_payload_t **out);
130
131 /**
132 * @brief Process a received EAP message.
133 *
134 * A eap_payload is created in "out" if result is NEED_MORE.
135 *
136 * @param this calling object
137 * @param in eap_payload response received
138 * @param out created eap_payload to send
139 * @return
140 * - NEED_MORE, if an other exchange is required
141 * - FAILED, if EAP method failed
142 * - SUCCESS, if EAP method succeeded
143 */
144 status_t (*process) (eap_method_t *this, eap_payload_t *in,
145 eap_payload_t **out);
146
147 /**
148 * @brief Get the EAP type implemented in this method.
149 *
150 * @param this calling object
151 * @return type of the EAP method
152 */
153 eap_type_t (*get_type) (eap_method_t *this);
154
155 /**
156 * @brief Check if this EAP method authenticates the server.
157 *
158 * Some EAP methods provide mutual authentication and
159 * allow authentication using only EAP, if the peer supports it.
160 *
161 * @param this calling object
162 * @return TRUE if methods provides mutual authentication
163 */
164 bool (*is_mutual) (eap_method_t *this);
165
166 /**
167 * @brief Get the MSK established by this EAP method.
168 *
169 * Not all EAP methods establish a shared secret.
170 *
171 * @param this calling object
172 * @param msk chunk receiving internal stored MSK
173 * @return
174 * - SUCCESS, or
175 * - FAILED, if MSK not established (yet)
176 */
177 status_t (*get_msk) (eap_method_t *this, chunk_t *msk);
178
179 /**
180 * @brief Destroys a eap_method_t object.
181 *
182 * @param this calling object
183 */
184 void (*destroy) (eap_method_t *this);
185 };
186
187 /**
188 * @brief Creates an EAP method for a specific type and role.
189 *
190 * @param eap_type EAP type to use
191 * @param role role of the eap_method, server or peer
192 * @param server ID of acting server
193 * @param peer ID of involved peer (client)
194 * @return eap_method_t object
195 *
196 * @ingroup eap
197 */
198 eap_method_t *eap_method_create(eap_type_t eap_type, eap_role_t role,
199 identification_t *server, identification_t *peer);
200
201 /**
202 * @brief (Re-)Load all EAP modules in the EAP modules directory.
203 *
204 * For security reasons, the directory and all it's modules must be owned
205 * by root and must not be writeable by someone else.
206 *
207 * @param dir directory of the EAP modules
208 *
209 * @ingroup eap
210 */
211 void eap_method_load(char *directory);
212
213 /**
214 * @brief Unload all loaded EAP modules
215 *
216 * @ingroup eap
217 */
218 void eap_method_unload();
219
220 /**
221 * @brief Constructor definition for a pluggable EAP module.
222 *
223 * Each EAP module must define a constructor function which will return
224 * an initialized object with the methods defined in eap_method_t. The
225 * constructor must be named eap_create() and it's signature must be equal
226 * to that of eap_constructor_t.
227 * A module may implement only a single role. If it does not support the role
228 * requested, NULL should be returned. Multiple modules are allowed of the
229 * same EAP type to support seperate implementations of peer/server.
230 *
231 * @param role role the module will play, peer or server
232 * @param server ID of the server to use for credential lookup
233 * @param peer ID of the peer to use for credential lookup
234 * @return implementation of the eap_method_t interface
235 *
236 * @ingroup eap
237 */
238 typedef eap_method_t *(*eap_constructor_t)(eap_role_t role,
239 identification_t *server,
240 identification_t *peer);
241
242 #endif /* EAP_METHOD_H_ */