xref: /freebsd/usr.sbin/ppp/pap.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1996 - 2001 Brian Somers <brian@Awfulhak.org>
5  *          based on work by Toshiharu OHNO <tony-o@iij.ad.jp>
6  *                           Internet Initiative Japan, Inc (IIJ)
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <netinet/in.h>
33 #include <netinet/in_systm.h>
34 #include <netinet/ip.h>
35 #include <sys/socket.h>
36 #include <sys/un.h>
37 
38 #include <stdlib.h>
39 #include <string.h>		/* strlen/memcpy */
40 #include <termios.h>
41 
42 #include "layer.h"
43 #include "mbuf.h"
44 #include "log.h"
45 #include "defs.h"
46 #include "timer.h"
47 #include "fsm.h"
48 #include "auth.h"
49 #include "pap.h"
50 #include "lqr.h"
51 #include "hdlc.h"
52 #include "lcp.h"
53 #include "proto.h"
54 #include "async.h"
55 #include "throughput.h"
56 #include "ccp.h"
57 #include "link.h"
58 #include "descriptor.h"
59 #include "physical.h"
60 #include "iplist.h"
61 #include "slcompress.h"
62 #include "ncpaddr.h"
63 #include "ipcp.h"
64 #include "filter.h"
65 #include "mp.h"
66 #ifndef NORADIUS
67 #include "radius.h"
68 #endif
69 #include "ipv6cp.h"
70 #include "ncp.h"
71 #include "bundle.h"
72 #include "chat.h"
73 #include "chap.h"
74 #include "cbcp.h"
75 #include "datalink.h"
76 
77 static const char * const papcodes[] = {
78   "???", "REQUEST", "SUCCESS", "FAILURE"
79 };
80 #define MAXPAPCODE (sizeof papcodes / sizeof papcodes[0] - 1)
81 
82 static void
pap_Req(struct authinfo * authp)83 pap_Req(struct authinfo *authp)
84 {
85   struct bundle *bundle = authp->physical->dl->bundle;
86   struct fsmheader lh;
87   struct mbuf *bp;
88   u_char *cp;
89   int namelen, keylen, plen;
90 
91   namelen = strlen(bundle->cfg.auth.name);
92   keylen = strlen(bundle->cfg.auth.key);
93   plen = namelen + keylen + 2;
94   log_Printf(LogDEBUG, "pap_Req: namelen = %d, keylen = %d\n", namelen, keylen);
95   log_Printf(LogPHASE, "Pap Output: %s ********\n", bundle->cfg.auth.name);
96   if (*bundle->cfg.auth.name == '\0')
97     log_Printf(LogWARN, "Sending empty PAP authname!\n");
98   lh.code = PAP_REQUEST;
99   lh.id = authp->id;
100   lh.length = htons(plen + sizeof(struct fsmheader));
101   bp = m_get(plen + sizeof(struct fsmheader), MB_PAPOUT);
102   memcpy(MBUF_CTOP(bp), &lh, sizeof(struct fsmheader));
103   cp = MBUF_CTOP(bp) + sizeof(struct fsmheader);
104   *cp++ = namelen;
105   memcpy(cp, bundle->cfg.auth.name, namelen);
106   cp += namelen;
107   *cp++ = keylen;
108   memcpy(cp, bundle->cfg.auth.key, keylen);
109   link_PushPacket(&authp->physical->link, bp, bundle,
110                   LINK_QUEUES(&authp->physical->link) - 1, PROTO_PAP);
111 }
112 
113 static void
SendPapCode(struct authinfo * authp,int code,const char * message)114 SendPapCode(struct authinfo *authp, int code, const char *message)
115 {
116   struct fsmheader lh;
117   struct mbuf *bp;
118   u_char *cp;
119   int plen, mlen;
120 
121   lh.code = code;
122   lh.id = authp->id;
123   mlen = strlen(message);
124   plen = mlen + 1;
125   lh.length = htons(plen + sizeof(struct fsmheader));
126   bp = m_get(plen + sizeof(struct fsmheader), MB_PAPOUT);
127   memcpy(MBUF_CTOP(bp), &lh, sizeof(struct fsmheader));
128   cp = MBUF_CTOP(bp) + sizeof(struct fsmheader);
129   /*
130    * If our message is longer than 255 bytes, truncate the length to
131    * 255 and send the entire message anyway.  Maybe the other end will
132    * display it... (see pap_Input() !)
133    */
134   *cp++ = mlen > 255 ? 255 : mlen;
135   memcpy(cp, message, mlen);
136   log_Printf(LogPHASE, "Pap Output: %s\n", papcodes[code]);
137 
138   link_PushPacket(&authp->physical->link, bp, authp->physical->dl->bundle,
139                   LINK_QUEUES(&authp->physical->link) - 1, PROTO_PAP);
140 }
141 
142 static void
pap_Success(struct authinfo * authp)143 pap_Success(struct authinfo *authp)
144 {
145   struct bundle *bundle = authp->physical->dl->bundle;
146 
147   datalink_GotAuthname(authp->physical->dl, authp->in.name);
148 #ifndef NORADIUS
149   if (*bundle->radius.cfg.file && bundle->radius.repstr)
150     SendPapCode(authp, PAP_ACK, bundle->radius.repstr);
151   else
152 #endif
153     SendPapCode(authp, PAP_ACK, "Greetings!!");
154   authp->physical->link.lcp.auth_ineed = 0;
155   if (Enabled(bundle, OPT_UTMP))
156     physical_Login(authp->physical, authp->in.name);
157 
158   if (authp->physical->link.lcp.auth_iwait == 0)
159     /*
160      * Either I didn't need to authenticate, or I've already been
161      * told that I got the answer right.
162      */
163     datalink_AuthOk(authp->physical->dl);
164 }
165 
166 static void
pap_Failure(struct authinfo * authp)167 pap_Failure(struct authinfo *authp)
168 {
169   SendPapCode(authp, PAP_NAK, "Login incorrect");
170   datalink_AuthNotOk(authp->physical->dl);
171 }
172 
173 void
pap_Init(struct authinfo * pap,struct physical * p)174 pap_Init(struct authinfo *pap, struct physical *p)
175 {
176   auth_Init(pap, p, pap_Req, pap_Success, pap_Failure);
177 }
178 
179 struct mbuf *
pap_Input(struct bundle * bundle,struct link * l,struct mbuf * bp)180 pap_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
181 {
182   struct physical *p = link2physical(l);
183   struct authinfo *authp = &p->dl->pap;
184   u_char nlen, klen, *key;
185   const char *txt;
186   int txtlen;
187 
188   if (p == NULL) {
189     log_Printf(LogERROR, "pap_Input: Not a physical link - dropped\n");
190     m_freem(bp);
191     return NULL;
192   }
193 
194   if (bundle_Phase(bundle) != PHASE_NETWORK &&
195       bundle_Phase(bundle) != PHASE_AUTHENTICATE) {
196     log_Printf(LogPHASE, "Unexpected pap input - dropped !\n");
197     m_freem(bp);
198     return NULL;
199   }
200 
201   if ((bp = auth_ReadHeader(authp, bp)) == NULL &&
202       ntohs(authp->in.hdr.length) == 0) {
203     log_Printf(LogWARN, "Pap Input: Truncated header !\n");
204     return NULL;
205   }
206 
207   if (authp->in.hdr.code == 0 || authp->in.hdr.code > MAXPAPCODE) {
208     log_Printf(LogPHASE, "Pap Input: %d: Bad PAP code !\n", authp->in.hdr.code);
209     m_freem(bp);
210     return NULL;
211   }
212 
213   if (authp->in.hdr.code != PAP_REQUEST && authp->id != authp->in.hdr.id &&
214       Enabled(bundle, OPT_IDCHECK)) {
215     /* Wrong conversation dude ! */
216     log_Printf(LogPHASE, "Pap Input: %s dropped (got id %d, not %d)\n",
217                papcodes[authp->in.hdr.code], authp->in.hdr.id, authp->id);
218     m_freem(bp);
219     return NULL;
220   }
221   m_settype(bp, MB_PAPIN);
222   authp->id = authp->in.hdr.id;		/* We respond with this id */
223 
224   if (bp) {
225     bp = mbuf_Read(bp, &nlen, 1);
226     if (authp->in.hdr.code == PAP_ACK) {
227       /*
228        * Don't restrict the length of our acknowledgement freetext to
229        * nlen (a one-byte length).  Show the rest of the ack packet
230        * instead.  This isn't really part of the protocol.....
231        */
232       bp = m_pullup(bp);
233       txt = MBUF_CTOP(bp);
234       txtlen = m_length(bp);
235     } else {
236       bp = auth_ReadName(authp, bp, nlen);
237       txt = authp->in.name;
238       txtlen = strlen(authp->in.name);
239     }
240   } else {
241     txt = "";
242     txtlen = 0;
243   }
244 
245   log_Printf(LogPHASE, "Pap Input: %s (%.*s)\n",
246              papcodes[authp->in.hdr.code], txtlen, txt);
247 
248   switch (authp->in.hdr.code) {
249     case PAP_REQUEST:
250       if (bp == NULL) {
251         log_Printf(LogPHASE, "Pap Input: No key given !\n");
252         break;
253       }
254       bp = mbuf_Read(bp, &klen, 1);
255       if (m_length(bp) < klen) {
256         log_Printf(LogERROR, "Pap Input: Truncated key !\n");
257         break;
258       }
259       if ((key = malloc(klen+1)) == NULL) {
260         log_Printf(LogERROR, "Pap Input: Out of memory !\n");
261         break;
262       }
263       bp = mbuf_Read(bp, key, klen);
264       key[klen] = '\0';
265 
266 #ifndef NORADIUS
267       if (*bundle->radius.cfg.file) {
268         if (!radius_Authenticate(&bundle->radius, authp, authp->in.name,
269                                  key, strlen(key), NULL, 0))
270           pap_Failure(authp);
271       } else
272 #endif
273       if (auth_Validate(bundle, authp->in.name, key))
274         pap_Success(authp);
275       else
276         pap_Failure(authp);
277 
278       free(key);
279       break;
280 
281     case PAP_ACK:
282       auth_StopTimer(authp);
283       if (p->link.lcp.auth_iwait == PROTO_PAP) {
284         p->link.lcp.auth_iwait = 0;
285         if (p->link.lcp.auth_ineed == 0)
286           /*
287            * We've succeeded in our ``login''
288            * If we're not expecting  the peer to authenticate (or he already
289            * has), proceed to network phase.
290            */
291           datalink_AuthOk(p->dl);
292       }
293       break;
294 
295     case PAP_NAK:
296       auth_StopTimer(authp);
297       datalink_AuthNotOk(p->dl);
298       break;
299   }
300 
301   m_freem(bp);
302   return NULL;
303 }
304