merged EAP framework from branch into trunk
[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_AKA = 23,
64 };
65
66 /**
67 * enum names for eap_type_t.
68 *
69 * @ingroup eap
70 */
71 extern enum_name_t *eap_type_names;
72
73 /**
74 * EAP code, type of an EAP message
75 *
76 * @ingroup eap
77 */
78 enum eap_code_t {
79 EAP_REQUEST = 1,
80 EAP_RESPONSE = 2,
81 EAP_SUCCESS = 3,
82 EAP_FAILURE = 4,
83 };
84
85 /**
86 * enum names for eap_code_t.
87 *
88 * @ingroup eap
89 */
90 extern enum_name_t *eap_code_names;
91
92
93 /**
94 * @brief Interface of an EAP method for server and client side.
95 *
96 * An EAP method initiates an EAP exchange and processes requests and
97 * responses. An EAP method may need multiple exchanges before succeeding, and
98 * the eap_authentication may use multiple EAP methods to authenticate a peer.
99 * To accomplish these requirements, all EAP methods have their own
100 * implementation while the eap_authenticatior uses one or more of these
101 * EAP methods. Sending of EAP(SUCCESS/FAILURE) message is not the job
102 * of the method, the eap_authenticator does this.
103 * An EAP method may establish a MSK, this is used the complete the
104 * authentication. Even if a mutual EAP method is used, the traditional
105 * AUTH payloads are required. Only these include the nonces and messages from
106 * ike_sa_init and therefore prevent man in the middle attacks.
107 *
108 * @b Constructors:
109 * - eap_method_create()
110 *
111 * @ingroup eap
112 */
113 struct eap_method_t {
114
115 /**
116 * @brief Initiate the EAP exchange.
117 *
118 * initiate() is only useable for server implementations, as clients only
119 * reply to server requests.
120 * A eap_payload is created in "out" if result is NEED_MORE.
121 *
122 * @param this calling object
123 * @param out eap_payload to send to the client
124 * @return
125 * - NEED_MORE, if an other exchange is required
126 * - FAILED, if unable to create eap request payload
127 */
128 status_t (*initiate) (eap_method_t *this, eap_payload_t **out);
129
130 /**
131 * @brief Process a received EAP message.
132 *
133 * A eap_payload is created in "out" if result is NEED_MORE.
134 *
135 * @param this calling object
136 * @param in eap_payload response received
137 * @param out created eap_payload to send
138 * @return
139 * - NEED_MORE, if an other exchange is required
140 * - FAILED, if EAP method failed
141 * - SUCCESS, if EAP method succeeded
142 */
143 status_t (*process) (eap_method_t *this, eap_payload_t *in,
144 eap_payload_t **out);
145
146 /**
147 * @brief Get the EAP type implemented in this method.
148 *
149 * @param this calling object
150 * @return type of the EAP method
151 */
152 eap_type_t (*get_type) (eap_method_t *this);
153
154 /**
155 * @brief Check if this EAP method authenticates the server.
156 *
157 * Some EAP methods provide mutual authentication and
158 * allow authentication using only EAP, if the peer supports it.
159 *
160 * @param this calling object
161 * @return TRUE if methods provides mutual authentication
162 */
163 bool (*is_mutual) (eap_method_t *this);
164
165 /**
166 * @brief Get the MSK established by this EAP method.
167 *
168 * Not all EAP methods establish a shared secret.
169 *
170 * @param this calling object
171 * @param msk chunk receiving internal stored MSK
172 * @return
173 * - SUCCESS, or
174 * - FAILED, if MSK not established (yet)
175 */
176 status_t (*get_msk) (eap_method_t *this, chunk_t *msk);
177
178 /**
179 * @brief Destroys a eap_method_t object.
180 *
181 * @param this calling object
182 */
183 void (*destroy) (eap_method_t *this);
184 };
185
186 /**
187 * @brief Creates an EAP method for a specific type and role.
188 *
189 * @param eap_type EAP type to use
190 * @param role role of the eap_method, server or peer
191 * @param server ID of acting server
192 * @param peer ID of involved peer (client)
193 * @return eap_method_t object
194 *
195 * @ingroup eap
196 */
197 eap_method_t *eap_method_create(eap_type_t eap_type, eap_role_t role,
198 identification_t *server, identification_t *peer);
199
200 /**
201 * @brief (Re-)Load all EAP modules in the EAP modules directory.
202 *
203 * For security reasons, the directory and all it's modules must be owned
204 * by root and must not be writeable by someone else.
205 *
206 * @param dir directory of the EAP modules
207 *
208 * @ingroup eap
209 */
210 void eap_method_load(char *directory);
211
212 /**
213 * @brief Unload all loaded EAP modules
214 *
215 * @ingroup eap
216 */
217 void eap_method_unload();
218
219 /**
220 * @brief Constructor definition for a pluggable EAP module.
221 *
222 * Each EAP module must define a constructor function which will return
223 * an initialized object with the methods defined in eap_method_t. The
224 * constructor must be named eap_create() and it's signature must be equal
225 * to that of eap_constructor_t.
226 * A module may implement only a single role. If it does not support the role
227 * requested, NULL should be returned. Multiple modules are allowed of the
228 * same EAP type to support seperate implementations of peer/server.
229 *
230 * @param role role the module will play, peer or server
231 * @param server ID of the server to use for credential lookup
232 * @param peer ID of the peer to use for credential lookup
233 * @return implementation of the eap_method_t interface
234 *
235 * @ingroup eap
236 */
237 typedef eap_method_t *(*eap_constructor_t)(eap_role_t role,
238 identification_t *server,
239 identification_t *peer);
240
241 #endif /* EAP_METHOD_H_ */