xref: /netbsd-src/external/bsd/ppp/dist/pppd/eap.h (revision f12839c5f795a8def46f685de6698463dbd213a9)
1 /*	$NetBSD: eap.h,v 1.6 2025/01/08 19:59:39 christos Exp $	*/
2 
3 /*
4  * eap.h - Extensible Authentication Protocol for PPP (RFC 2284)
5  *
6  * Copyright (c) 2001 by Sun Microsystems, Inc.
7  * All rights reserved.
8  *
9  * Non-exclusive rights to redistribute, modify, translate, and use
10  * this software in source and binary forms, in whole or in part, is
11  * hereby granted, provided that the above copyright notice is
12  * duplicated in any source form, and that neither the name of the
13  * copyright holder nor the author is used to endorse or promote
14  * products derived from this software.
15  *
16  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19  *
20  * Original version by James Carlson
21  */
22 
23 #ifndef PPP_EAP_H
24 #define	PPP_EAP_H
25 
26 #include "pppdconf.h"
27 
28 #ifdef	__cplusplus
29 extern "C" {
30 #endif
31 
32 
33 #ifndef PPP_EAP
34 #define PPP_EAP 0xc227
35 #endif
36 
37 
38 /*
39  * Packet header = Code, id, length.
40  */
41 #define	EAP_HEADERLEN	4
42 
43 
44 /* EAP message codes. */
45 #define	EAP_REQUEST	1
46 #define	EAP_RESPONSE	2
47 #define	EAP_SUCCESS	3
48 #define	EAP_FAILURE	4
49 
50 /* EAP types */
51 #define	EAPT_IDENTITY		1
52 #define	EAPT_NOTIFICATION	2
53 #define	EAPT_NAK		3	/* (response only) */
54 #define	EAPT_MD5CHAP		4
55 #define	EAPT_OTP		5	/* One-Time Password; RFC 1938 */
56 #define	EAPT_TOKEN		6	/* Generic Token Card */
57 /* 7 and 8 are unassigned. */
58 #define	EAPT_RSA		9	/* RSA Public Key Authentication */
59 #define	EAPT_DSS		10	/* DSS Unilateral */
60 #define	EAPT_KEA		11	/* KEA */
61 #define	EAPT_KEA_VALIDATE	12	/* KEA-VALIDATE	*/
62 #define	EAPT_TLS		13	/* EAP-TLS */
63 #define	EAPT_DEFENDER		14	/* Defender Token (AXENT) */
64 #define	EAPT_W2K		15	/* Windows 2000 EAP */
65 #define	EAPT_ARCOT		16	/* Arcot Systems */
66 #define	EAPT_CISCOWIRELESS	17	/* Cisco Wireless */
67 #define	EAPT_NOKIACARD		18	/* Nokia IP smart card */
68 #define	EAPT_SRP		19	/* Secure Remote Password */
69 /* 20 is deprecated */
70 #define	EAPT_TTLS		21	/* EAP Tunneled TLS Authentication Protocol RFC5281 */
71 #define	EAPT_RAS		22	/* Remote Access Service */
72 #define	EAPT_AKA		23	/* EAP method for 3rd Generation Authentication and Key Agreement RFC4187 */
73 #define	EAPT_3COM		24	/* EAP-3Com Wireless */
74 #define	EAPT_PEAP		25	/* Protected EAP */
75 #define	EAPT_MSCHAPV2		26	/* EAP-MSCHAPv2 RFC-draft-kamath-pppext-eap-mschapv2-02 */
76 
77 /* OpCodes for MSCHAPv2 */
78 #define CHAP_CHALLENGE		1
79 #define CHAP_RESPONSE		2
80 #define CHAP_SUCCESS		3
81 #define CHAP_FAILURE		4
82 
83 /* EAP SRP-SHA1 Subtypes */
84 #define	EAPSRP_CHALLENGE	1	/* Request 1 - Challenge */
85 #define	EAPSRP_CKEY		1	/* Response 1 - Client Key */
86 #define	EAPSRP_SKEY		2	/* Request 2 - Server Key */
87 #define	EAPSRP_CVALIDATOR	2	/* Response 2 - Client Validator */
88 #define	EAPSRP_SVALIDATOR	3	/* Request 3 - Server Validator */
89 #define	EAPSRP_ACK		3	/* Response 3 - final ack */
90 #define	EAPSRP_LWRECHALLENGE	4	/* Req/resp 4 - Lightweight rechal */
91 
92 #define	SRPVAL_EBIT	0x00000001	/* Use shared key for ECP */
93 
94 #define	SRP_PSEUDO_ID	"pseudo_"
95 #define	SRP_PSEUDO_LEN	7
96 
97 #define MIN_CHALLENGE_LENGTH	16
98 #define MAX_CHALLENGE_LENGTH	24
99 
100 enum eap_state_code {
101 	eapInitial = 0,	/* No EAP authentication yet requested */
102 	eapPending,	/* Waiting for LCP (no timer) */
103 	eapClosed,	/* Authentication not in use */
104 	eapListen,	/* Client ready (and timer running) */
105 	eapIdentify,	/* EAP Identify sent */
106 	eapTlsStart,	/* Send EAP-TLS start packet */
107 	eapTlsRecv,	/* Receive EAP-TLS tls data */
108 	eapTlsSendAck,	/* Send EAP-TLS ack */
109 	eapTlsSend,	/* Send EAP-TLS tls data */
110 	eapTlsRecvAck,	/* Receive EAP-TLS ack */
111 	eapTlsRecvClient, 	/* Receive EAP-TLS auth response from client*/
112 	eapTlsSendAlert,	/* Send EAP-TLS tls alert (server)*/
113 	eapTlsRecvAlertAck,	/* Receive EAP-TLS ack after sending alert */
114 	eapTlsRecvSuccess,	/* Receive EAP success */
115 	eapTlsRecvFailure,	/* Receive EAP failure */
116 	eapSRP1,	/* Sent EAP SRP-SHA1 Subtype 1 */
117 	eapSRP2,	/* Sent EAP SRP-SHA1 Subtype 2 */
118 	eapSRP3,	/* Sent EAP SRP-SHA1 Subtype 3 */
119 	eapMD5Chall,	/* Sent MD5-Challenge */
120 	eapMSCHAPv2Chall,	/* Sent MSCHAPv2-Challenge */
121 	eapOpen,	/* Completed authentication */
122 	eapSRP4,	/* Sent EAP SRP-SHA1 Subtype 4 */
123 	eapBadAuth	/* Failed authentication */
124 };
125 
126 #define	EAP_STATES	\
127 	"Initial", "Pending", "Closed", "Listen", "Identify", \
128 	"TlsStart", "TlsRecv", "TlsSendAck", "TlsSend", "TlsRecvAck", "TlsRecvClient",\
129 	"TlsSendAlert", "TlsRecvAlertAck" , "TlsRecvSuccess", "TlsRecvFailure", \
130 	"SRP1", "SRP2", "SRP3", "MD5Chall", "MSCHAPv2Chall", "Open", "SRP4", "BadAuth"
131 
132 #ifdef PPP_WITH_EAPTLS
133 #define	eap_client_active(esp)	((esp)->es_client.ea_state != eapInitial &&\
134 				 (esp)->es_client.ea_state != eapPending &&\
135 				 (esp)->es_client.ea_state != eapClosed)
136 #else
137 #define eap_client_active(esp)	((esp)->es_client.ea_state == eapListen)
138 #endif /* PPP_WITH_EAPTLS */
139 
140 #define	eap_server_active(esp)	\
141 	((esp)->es_server.ea_state >= eapIdentify && \
142 	 (esp)->es_server.ea_state <= eapMD5Chall)
143 
144 struct eap_auth {
145 	char *ea_name;		/* Our name */
146 	char *ea_peer;		/* Peer's name */
147 	void *ea_session;	/* Authentication library linkage */
148 	unsigned char *ea_skey;	/* Shared encryption key */
149 	int ea_timeout;		/* Time to wait (for retransmit/fail) */
150 	int ea_maxrequests;	/* Max Requests allowed */
151 	unsigned short ea_namelen;	/* Length of our name */
152 	unsigned short ea_peerlen;	/* Length of peer's name */
153 	enum eap_state_code ea_state;
154 #ifdef PPP_WITH_EAPTLS
155 	enum eap_state_code ea_prev_state;
156 #endif
157 #ifdef PPP_WITH_CHAPMS
158         struct chap_digest_type *digest;
159 #endif
160 	unsigned char ea_id;		/* Current id */
161 	unsigned char ea_requests;	/* Number of Requests sent/received */
162 	unsigned char ea_responses;	/* Number of Responses */
163 	unsigned char ea_type;		/* One of EAPT_* */
164 	uint32_t ea_keyflags;	/* SRP shared key usage flags */
165 #ifdef PPP_WITH_EAPTLS
166 	bool ea_using_eaptls;
167 #endif
168 };
169 
170 /*
171  * Complete EAP state for one PPP session.
172  */
173 typedef struct eap_state {
174 	int es_unit;			/* Interface unit number */
175 	struct eap_auth es_client;	/* Client (authenticatee) data */
176 	struct eap_auth es_server;	/* Server (authenticator) data */
177 #ifdef PPP_WITH_PEAP
178 	struct peap_state *ea_peap;	/* Client PEAP (authenticator) data */
179 #endif
180 	int es_savedtime;		/* Saved timeout */
181 	int es_rechallenge;		/* EAP rechallenge interval */
182 	int es_lwrechallenge;		/* SRP lightweight rechallenge inter */
183 	bool es_usepseudo;		/* Use SRP Pseudonym if offered one */
184 	int es_usedpseudo;		/* Set if we already sent PN */
185 	int es_challen;			/* Length of challenge string */
186 	unsigned char es_challenge[MAX_CHALLENGE_LENGTH];
187 } eap_state;
188 
189 /*
190  * Timeouts.
191  */
192 #define	EAP_DEFTIMEOUT		3	/* Timeout (seconds) for rexmit */
193 #ifdef PPP_WITH_EAPTLS
194 #define	EAP_DEFTRANSMITS	30	/* max # times to transmit */
195 					/* certificates can be long ... */
196 #else
197 #define	EAP_DEFTRANSMITS	10	/* max # times to transmit */
198 #endif /* PPP_WITH_EAPTLS */
199 #define	EAP_DEFREQTIME		20	/* Time to wait for peer request */
200 #define	EAP_DEFALLOWREQ		20	/* max # times to accept requests */
201 
202 extern eap_state eap_states[];
203 
204 void eap_authwithpeer (int unit, char *localname);
205 void eap_authpeer (int unit, char *localname);
206 
207 extern struct protent eap_protent;
208 
209 #ifdef PPP_WITH_EAPTLS
210 typedef int (eaptls_passwd_hook_fn)(char *user, char *passwd);
211 extern eaptls_passwd_hook_fn *eaptls_passwd_hook;
212 #endif
213 
214 #ifdef	__cplusplus
215 }
216 #endif
217 
218 #endif /* PPP_EAP_H */
219 
220