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