/* * upap.c - User/Password Authentication Protocol. * * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in *    the documentation and/or other materials provided with the *    distribution. * * 3. The name "Carnegie Mellon University" must not be used to *    endorse or promote products derived from this software without *    prior written permission. For permission or any legal *    details, please contact *      Office of Technology Transfer *      Carnegie Mellon University *      5000 Forbes Avenue *      Pittsburgh, PA  15213-3890 *      (412) 268-4387, fax: (412) 268-7395 *      tech-transfer@andrew.cmu.edu * * 4. Redistributions of any form whatsoever must retain the following *    acknowledgment: *    "This product includes software developed by Computing Services *     at Carnegie Mellon University (http://www.cmu.edu/computing/)." * * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */#define RCSID	"$Id: upap.c,v 1.30 2005/07/13 10:41:58 paulus Exp $"/* * TODO: */#include <stdio.h>#include <string.h>#include "pppd.h"#include "upap.h"static const char rcsid[] = RCSID;static bool hide_password = 1;/* * Command-line options. */static option_t pap_option_list[] = {    { "hide-password", o_bool, &hide_password,      "Don't output passwords to log", OPT_PRIO | 1 },    { "show-password", o_bool, &hide_password,      "Show password string in debug log messages", OPT_PRIOSUB | 0 },    { "pap-restart", o_int, &upap[0].us_timeouttime,      "Set retransmit timeout for PAP", OPT_PRIO },    { "pap-max-authreq", o_int, &upap[0].us_maxtransmits,      "Set max number of transmissions for auth-reqs", OPT_PRIO },    { "pap-timeout", o_int, &upap[0].us_reqtimeout,      "Set time limit for peer PAP authentication", OPT_PRIO },    { NULL }};/* * Protocol entry points. */static void upap_init __P((int));static void upap_lowerup __P((int));static void upap_lowerdown __P((int));static void upap_input __P((int, u_char *, int));static void upap_protrej __P((int));static int  upap_printpkt __P((u_char *, int,			       void (*) __P((void *, char *, ...)), void *));struct protent pap_protent = {    PPP_PAP,    upap_init,    upap_input,    upap_protrej,    upap_lowerup,    upap_lowerdown,    NULL,    NULL,    upap_printpkt,    NULL,    1,    "PAP",    NULL,    pap_option_list,    NULL,    NULL,    NULL};upap_state upap[NUM_PPP];		/* UPAP state; one for each unit */static void upap_timeout __P((void *));static void upap_reqtimeout __P((void *));static void upap_rauthreq __P((upap_state *, u_char *, int, int));static void upap_rauthack __P((upap_state *, u_char *, int, int));static void upap_rauthnak __P((upap_state *, u_char *, int, int));static void upap_sauthreq __P((upap_state *));static void upap_sresp __P((upap_state *, int, int, char *, int));/* * upap_init - Initialize a UPAP unit. */static voidupap_init(unit)    int unit;{    upap_state *u = &upap[unit];    u->us_unit = unit;    u->us_user = NULL;    u->us_userlen = 0;    u->us_passwd = NULL;    u->us_passwdlen = 0;    u->us_clientstate = UPAPCS_INITIAL;    u->us_serverstate = UPAPSS_INITIAL;    u->us_id = 0;    u->us_timeouttime = UPAP_DEFTIMEOUT;    u->us_maxtransmits = 10;    u->us_reqtimeout = UPAP_DEFREQTIME;}/* * upap_authwithpeer - Authenticate us with our peer (start client). * * Set new state and send authenticate's. */voidupap_authwithpeer(unit, user, password)    int unit;    char *user, *password;{    upap_state *u = &upap[unit];    /* Save the username and password we're given */    u->us_user = user;    u->us_userlen = strlen(user);    u->us_passwd = password;    u->us_passwdlen = strlen(password);    u->us_transmits = 0;    /* Lower layer up yet? */    if (u->us_clientstate == UPAPCS_INITIAL ||	u->us_clientstate == UPAPCS_PENDING) {	u->us_clientstate = UPAPCS_PENDING;	return;    }    upap_sauthreq(u);			/* Start protocol */}/* * upap_authpeer - Authenticate our peer (start server). * * Set new state. */voidupap_authpeer(unit)    int unit;{    upap_state *u = &upap[unit];    /* Lower layer up yet? */    if (u->us_serverstate == UPAPSS_INITIAL ||	u->us_serverstate == UPAPSS_PENDING) {	u->us_serverstate = UPAPSS_PENDING;	return;    }    u->us_serverstate = UPAPSS_LISTEN;    if (u->us_reqtimeout > 0)	TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);}/* * upap_timeout - Retransmission timer for sending auth-reqs expired. */static voidupap_timeout(arg)    void *arg;{    upap_state *u = (upap_state *) arg;    if (u->us_clientstate != UPAPCS_AUTHREQ)	return;    if (u->us_transmits >= u->us_maxtransmits) {	/* give up in disgust */	error("No response to PAP authenticate-requests");	u->us_clientstate = UPAPCS_BADAUTH;	auth_withpeer_fail(u->us_unit, PPP_PAP);	return;    }    upap_sauthreq(u);		/* Send Authenticate-Request */}/* * upap_reqtimeout - Give up waiting for the peer to send an auth-req. */static voidupap_reqtimeout(arg)    void *arg;{    upap_state *u = (upap_state *) arg;    if (u->us_serverstate != UPAPSS_LISTEN)	return;			/* huh?? */    auth_peer_fail(u->us_unit, PPP_PAP);    u->us_serverstate = UPAPSS_BADAUTH;}/* * upap_lowerup - The lower layer is up. * * Start authenticating if pending. */static voidupap_lowerup(unit)    int unit;{    upap_state *u = &upap[unit];    if (u->us_clientstate == UPAPCS_INITIAL)	u->us_clientstate = UPAPCS_CLOSED;    else if (u->us_clientstate == UPAPCS_PENDING) {	upap_sauthreq(u);	/* send an auth-request */    }    if (u->us_serverstate == UPAPSS_INITIAL)	u->us_serverstate = UPAPSS_CLOSED;    else if (u->us_serverstate == UPAPSS_PENDING) {	u->us_serverstate = UPAPSS_LISTEN;	if (u->us_reqtimeout > 0)	    TIMEOUT(upap_reqtimeout, u, u->us_reqtimeout);    }}/* * upap_lowerdown - The lower layer is down. * * Cancel all timeouts. */static voidupap_lowerdown(unit)    int unit;{    upap_state *u = &upap[unit];    if (u->us_clientstate == UPAPCS_AUTHREQ)	/* Timeout pending? */	UNTIMEOUT(upap_timeout, u);		/* Cancel timeout */    if (u->us_serverstate == UPAPSS_LISTEN && u->us_reqtimeout > 0)	UNTIMEOUT(upap_reqtimeout, u);    u->us_clientstate = UPAPCS_INITIAL;    u->us_serverstate = UPAPSS_INITIAL;}/* * upap_protrej - Peer doesn't speak this protocol. * * This shouldn't happen.  In any case, pretend lower layer went down. */static voidupap_protrej(unit)    int unit;{    upap_state *u = &upap[unit];    if (u->us_clientstate == UPAPCS_AUTHREQ) {	error("PAP authentication failed due to protocol-reject");	auth_withpeer_fail(unit, PPP_PAP);    }    if (u->us_serverstate == UPAPSS_LISTEN) {	error("PAP authentication of peer failed (protocol-reject)");	auth_peer_fail(unit, PPP_PAP);    }    upap_lowerdown(unit);}/* * upap_input - Input UPAP packet. */static voidupap_input(unit, inpacket, l)    int unit;    u_char *inpacket;    int l;{    upap_state *u = &upap[unit];    u_char *inp;    u_char code, id;    int len;    /*     * Parse header (code, id and length).     * If packet too short, drop it.     */    inp = inpacket;    if (l < UPAP_HEADERLEN) {	UPAPDEBUG(("pap_input: rcvd short header."));	return;    }    GETCHAR(code, inp);    GETCHAR(id, inp);    GETSHORT(len, inp);    if (len < UPAP_HEADERLEN) {	UPAPDEBUG(("pap_input: rcvd illegal length."));	return;    }    if (len > l) {	UPAPDEBUG(("pap_input: rcvd short packet."));	return;    }