2 * upap.c - User/Password Authentication Protocol.
4 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
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7 * modification, are permitted provided that the following conditions
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31 * "This product includes software developed by Computing Services
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34 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
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43 #define RCSID "$Id: upap.c,v 1.29 2002/12/04 23:03:33 paulus Exp $"
55 static const char rcsid[] = RCSID;
57 static bool hide_password = 1;
60 * Command-line options.
62 static option_t pap_option_list[] = {
63 { "hide-password", o_bool, &hide_password,
64 "Don't output passwords to log", OPT_PRIO | 1 },
65 { "show-password", o_bool, &hide_password,
66 "Show password string in debug log messages", OPT_PRIOSUB | 0 },
68 { "pap-restart", o_int, &upap[0].us_timeouttime,
69 "Set retransmit timeout for PAP", OPT_PRIO },
70 { "pap-max-authreq", o_int, &upap[0].us_maxtransmits,
71 "Set max number of transmissions for auth-reqs", OPT_PRIO },
72 { "pap-timeout", o_int, &upap[0].us_reqtimeout,
73 "Set time limit for peer PAP authentication", OPT_PRIO },
79 * Protocol entry points.
81 static void upap_init __P((int));
82 static void upap_lowerup __P((int));
83 static void upap_lowerdown __P((int));
84 static void upap_input __P((int, u_char *, int));
85 static void upap_protrej __P((int));
86 static int upap_printpkt __P((u_char *, int,
87 void (*) __P((void *, char *, ...)), void *));
89 struct protent pap_protent = {
109 upap_state upap[NUM_PPP]; /* UPAP state; one for each unit */
111 static void upap_timeout __P((void *));
112 static void upap_reqtimeout __P((void *));
113 static void upap_rauthreq __P((upap_state *, u_char *, int, int));
114 static void upap_rauthack __P((upap_state *, u_char *, int, int));
115 static void upap_rauthnak __P((upap_state *, u_char *, int, int));
116 static void upap_sauthreq __P((upap_state *));
117 static void upap_sresp __P((upap_state *, int, int, char *, int));
121 * upap_init - Initialize a UPAP unit.
127 upap_state *u = &upap[unit];
134 u->us_clientstate = UPAPCS_INITIAL;
135 u->us_serverstate = UPAPSS_INITIAL;
137 u->us_timeouttime = UPAP_DEFTIMEOUT;
138 u->us_maxtransmits = 10;
139 u->us_reqtimeout = UPAP_DEFREQTIME;
144 * upap_authwithpeer - Authenticate us with our peer (start client).
146 * Set new state and send authenticate's.
149 upap_authwithpeer(unit, user, password)
151 char *user, *password;
153 upap_state *u = &upap[unit];
155 /* Save the username and password we're given */
157 u->us_userlen = strlen(user);
158 u->us_passwd = password;
159 u->us_passwdlen = strlen(password);
162 /* Lower layer up yet? */
163 if (u->us_clientstate == UPAPCS_INITIAL ||
164 u->us_clientstate == UPAPCS_PENDING) {
165 u->us_clientstate = UPAPCS_PENDING;
169 upap_sauthreq(u); /* Start protocol */
174 * upap_authpeer - Authenticate our peer (start server).
182 upap_state *u = &upap[unit];
184 /* Lower layer up yet? */
185 if (u->us_serverstate == UPAPSS_INITIAL ||
186 u->us_serverstate == UPAPSS_PENDING) {
187 u->us_serverstate = UPAPSS_PENDING;
191 u->us_serverstate = UPAPSS_LISTEN;
192 if (u->us_reqtimeout > 0)
193 TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
198 * upap_timeout - Retransmission timer for sending auth-reqs expired.
204 upap_state *u = (upap_state *) arg;
206 if (u->us_clientstate != UPAPCS_AUTHREQ)
209 if (u->us_transmits >= u->us_maxtransmits) {
210 /* give up in disgust */
211 error("No response to PAP authenticate-requests");
212 u->us_clientstate = UPAPCS_BADAUTH;
213 auth_withpeer_fail(u->us_unit, PPP_PAP);
217 upap_sauthreq(u); /* Send Authenticate-Request */
222 * upap_reqtimeout - Give up waiting for the peer to send an auth-req.
228 upap_state *u = (upap_state *) arg;
230 if (u->us_serverstate != UPAPSS_LISTEN)
233 auth_peer_fail(u->us_unit, PPP_PAP);
234 u->us_serverstate = UPAPSS_BADAUTH;
239 * upap_lowerup - The lower layer is up.
241 * Start authenticating if pending.
247 upap_state *u = &upap[unit];
249 if (u->us_clientstate == UPAPCS_INITIAL)
250 u->us_clientstate = UPAPCS_CLOSED;
251 else if (u->us_clientstate == UPAPCS_PENDING) {
252 upap_sauthreq(u); /* send an auth-request */
255 if (u->us_serverstate == UPAPSS_INITIAL)
256 u->us_serverstate = UPAPSS_CLOSED;
257 else if (u->us_serverstate == UPAPSS_PENDING) {
258 u->us_serverstate = UPAPSS_LISTEN;
259 if (u->us_reqtimeout > 0)
260 TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);
266 * upap_lowerdown - The lower layer is down.
268 * Cancel all timeouts.
274 upap_state *u = &upap[unit];
276 if (u->us_clientstate == UPAPCS_AUTHREQ) /* Timeout pending? */
277 UNTIMEOUT(upap_timeout, u); /* Cancel timeout */
278 if (u->us_serverstate == UPAPSS_LISTEN && u->us_reqtimeout > 0)
279 UNTIMEOUT(upap_reqtimeout, u);
281 u->us_clientstate = UPAPCS_INITIAL;
282 u->us_serverstate = UPAPSS_INITIAL;
287 * upap_protrej - Peer doesn't speak this protocol.
289 * This shouldn't happen. In any case, pretend lower layer went down.
295 upap_state *u = &upap[unit];
297 if (u->us_clientstate == UPAPCS_AUTHREQ) {
298 error("PAP authentication failed due to protocol-reject");
299 auth_withpeer_fail(unit, PPP_PAP);
301 if (u->us_serverstate == UPAPSS_LISTEN) {
302 error("PAP authentication of peer failed (protocol-reject)");
303 auth_peer_fail(unit, PPP_PAP);
305 upap_lowerdown(unit);
310 * upap_input - Input UPAP packet.
313 upap_input(unit, inpacket, l)
318 upap_state *u = &upap[unit];
324 * Parse header (code, id and length).
325 * If packet too short, drop it.
328 if (l < UPAP_HEADERLEN) {
329 UPAPDEBUG(("pap_input: rcvd short header."));
335 if (len < UPAP_HEADERLEN) {
336 UPAPDEBUG(("pap_input: rcvd illegal length."));
340 UPAPDEBUG(("pap_input: rcvd short packet."));
343 len -= UPAP_HEADERLEN;
346 * Action depends on code.
350 upap_rauthreq(u, inp, id, len);
354 upap_rauthack(u, inp, id, len);
358 upap_rauthnak(u, inp, id, len);
361 default: /* XXX Need code reject */
368 * upap_rauth - Receive Authenticate.
371 upap_rauthreq(u, inp, id, len)
377 u_char ruserlen, rpasswdlen;
378 char *ruser, *rpasswd;
384 if (u->us_serverstate < UPAPSS_LISTEN)
388 * If we receive a duplicate authenticate-request, we are
389 * supposed to return the same status as for the first request.
391 if (u->us_serverstate == UPAPSS_OPEN) {
392 upap_sresp(u, UPAP_AUTHACK, id, "", 0); /* return auth-ack */
395 if (u->us_serverstate == UPAPSS_BADAUTH) {
396 upap_sresp(u, UPAP_AUTHNAK, id, "", 0); /* return auth-nak */
404 UPAPDEBUG(("pap_rauth: rcvd short packet."));
407 GETCHAR(ruserlen, inp);
408 len -= sizeof (u_char) + ruserlen + sizeof (u_char);
410 UPAPDEBUG(("pap_rauth: rcvd short packet."));
413 ruser = (char *) inp;
414 INCPTR(ruserlen, inp);
415 GETCHAR(rpasswdlen, inp);
416 if (len < rpasswdlen) {
417 UPAPDEBUG(("pap_rauth: rcvd short packet."));
420 rpasswd = (char *) inp;
423 * Check the username and password given.
425 retcode = check_passwd(u->us_unit, ruser, ruserlen, rpasswd,
427 BZERO(rpasswd, rpasswdlen);
430 * Check remote number authorization. A plugin may have filled in
431 * the remote number or added an allowed number, and rather than
432 * return an authenticate failure, is leaving it for us to verify.
434 if (retcode == UPAP_AUTHACK) {
435 if (!auth_number()) {
436 /* We do not want to leak info about the pap result. */
437 retcode = UPAP_AUTHNAK; /* XXX exit value will be "wrong" */
438 warn("calling number %q is not authorized", remote_number);
442 msglen = strlen(msg);
445 upap_sresp(u, retcode, id, msg, msglen);
447 /* Null terminate and clean remote name. */
448 slprintf(rhostname, sizeof(rhostname), "%.*v", ruserlen, ruser);
450 if (retcode == UPAP_AUTHACK) {
451 u->us_serverstate = UPAPSS_OPEN;
452 notice("PAP peer authentication succeeded for %q", rhostname);
453 auth_peer_success(u->us_unit, PPP_PAP, 0, ruser, ruserlen);
455 u->us_serverstate = UPAPSS_BADAUTH;
456 warn("PAP peer authentication failed for %q", rhostname);
457 auth_peer_fail(u->us_unit, PPP_PAP);
460 if (u->us_reqtimeout > 0)
461 UNTIMEOUT(upap_reqtimeout, u);
466 * upap_rauthack - Receive Authenticate-Ack.
469 upap_rauthack(u, inp, id, len)
478 if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
485 UPAPDEBUG(("pap_rauthack: ignoring missing msg-length."));
487 GETCHAR(msglen, inp);
489 len -= sizeof (u_char);
491 UPAPDEBUG(("pap_rauthack: rcvd short packet."));
495 PRINTMSG(msg, msglen);
499 u->us_clientstate = UPAPCS_OPEN;
501 notice("PAP authentication succeeded");
502 auth_withpeer_success(u->us_unit, PPP_PAP, 0);
507 * upap_rauthnak - Receive Authenticate-Nak.
510 upap_rauthnak(u, inp, id, len)
519 if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
526 UPAPDEBUG(("pap_rauthnak: ignoring missing msg-length."));
528 GETCHAR(msglen, inp);
530 len -= sizeof (u_char);
532 UPAPDEBUG(("pap_rauthnak: rcvd short packet."));
536 PRINTMSG(msg, msglen);
540 u->us_clientstate = UPAPCS_BADAUTH;
542 error("PAP authentication failed");
543 auth_withpeer_fail(u->us_unit, PPP_PAP);
548 * upap_sauthreq - Send an Authenticate-Request.
557 outlen = UPAP_HEADERLEN + 2 * sizeof (u_char) +
558 u->us_userlen + u->us_passwdlen;
559 outp = outpacket_buf;
561 MAKEHEADER(outp, PPP_PAP);
563 PUTCHAR(UPAP_AUTHREQ, outp);
564 PUTCHAR(++u->us_id, outp);
565 PUTSHORT(outlen, outp);
566 PUTCHAR(u->us_userlen, outp);
567 BCOPY(u->us_user, outp, u->us_userlen);
568 INCPTR(u->us_userlen, outp);
569 PUTCHAR(u->us_passwdlen, outp);
570 BCOPY(u->us_passwd, outp, u->us_passwdlen);
572 output(u->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
574 TIMEOUT(upap_timeout, u, u->us_timeouttime);
576 u->us_clientstate = UPAPCS_AUTHREQ;
581 * upap_sresp - Send a response (ack or nak).
584 upap_sresp(u, code, id, msg, msglen)
593 outlen = UPAP_HEADERLEN + sizeof (u_char) + msglen;
594 outp = outpacket_buf;
595 MAKEHEADER(outp, PPP_PAP);
599 PUTSHORT(outlen, outp);
600 PUTCHAR(msglen, outp);
601 BCOPY(msg, outp, msglen);
602 output(u->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
606 * upap_printpkt - print the contents of a PAP packet.
608 static char *upap_codenames[] = {
609 "AuthReq", "AuthAck", "AuthNak"
613 upap_printpkt(p, plen, printer, arg)
616 void (*printer) __P((void *, char *, ...));
620 int mlen, ulen, wlen;
621 char *user, *pwd, *msg;
624 if (plen < UPAP_HEADERLEN)
630 if (len < UPAP_HEADERLEN || len > plen)
633 if (code >= 1 && code <= sizeof(upap_codenames) / sizeof(char *))
634 printer(arg, " %s", upap_codenames[code-1]);
636 printer(arg, " code=0x%x", code);
637 printer(arg, " id=0x%x", id);
638 len -= UPAP_HEADERLEN;
647 if (len < ulen + wlen + 2)
649 user = (char *) (p + 1);
650 pwd = (char *) (p + ulen + 2);
651 p += ulen + wlen + 2;
652 len -= ulen + wlen + 2;
653 printer(arg, " user=");
654 print_string(user, ulen, printer, arg);
655 printer(arg, " password=");
657 print_string(pwd, wlen, printer, arg);
659 printer(arg, "<hidden>");
668 msg = (char *) (p + 1);
672 print_string(msg, mlen, printer, arg);
676 /* print the rest of the bytes in the packet */
677 for (; len > 0; --len) {
679 printer(arg, " %.2x", code);