/*****************************************************************************
* netauth.c - Network Authentication and Phase Control program file.
*
* Copyright (c) 1997 by Global Election Systems Inc.  All rights reserved.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
*   Ported from public pppd code.
*****************************************************************************/
/*
 * auth.c - PPP authentication and phase control.
 *
 * Copyright (c) 1993 The Australian National University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by the Australian National University.  The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Copyright (c) 1989 Carnegie Mellon University.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that the above copyright notice and this paragraph are
 * duplicated in all such forms and that any documentation,
 * advertising materials, and other materials related to such
 * distribution and use acknowledge that the software was developed
 * by Carnegie Mellon University.  The name of the
 * University may not be used to endorse or promote products derived
 * from this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include "netconf.h"

#include <string.h>
#include "net.h"
#include "netbuf.h"
#include "nettimer.h"
#include "netfsm.h"
#include "netlcp.h"
#include "netpap.h"
#include "netchap.h"
#include "netauth.h"
#include "netppp.h"
#include "netipcp.h"
#include "netos.h"

#if CBCP_SUPPORT > 0
#include "netcbcp.h"
#endif

#include <malloc.h>
#include <stdio.h>
#include "netdebug.h"


/*************************/
/*** LOCAL DEFINITIONS ***/
/*************************/

/* Bits in auth_pending[] */
#define PAP_WITHPEER    1
#define PAP_PEER    2
#define CHAP_WITHPEER   4
#define CHAP_PEER   8


                                                                    
/************************/
/*** LOCAL DATA TYPES ***/
/************************/
/* Used for storing a sequence of words.  Usually malloced. */
struct wordlist {
    struct wordlist *next;
    char        word[1];
};



/***********************************/
/*** LOCAL FUNCTION DECLARATIONS ***/
/***********************************/
extern char *crypt __P((const char *, const char *));

/* Prototypes for procedures local to this file. */

static void network_phase __P((int));
static void check_idle __P((void *));
static void connect_time_expired __P((void *));
#ifdef XXX
static int  login __P((char *, char *, char **, int *));
#endif
static void logout __P((void));
static int  null_login __P((int));
static int  get_pap_passwd __P((int));
static int  have_pap_secret __P((void));
static int  have_chap_secret __P((char *, char *, u_int32_t));
static int  ip_addr_check __P((u_int32_t, struct wordlist *));
#if PAP_SUPPORT > 0 || CHAP_SUPPORT > 0
static void set_allowed_addrs(int unit, struct wordlist *addrs);
static void free_wordlist __P((struct wordlist *));
#endif
#if CBCP_SUPPORT > 0
static void callback_phase __P((int));
#endif


/******************************/
/*** PUBLIC DATA STRUCTURES ***/
/******************************/


/*****************************/
/*** LOCAL DATA STRUCTURES ***/
/*****************************/
#if PAP_SUPPORT > 0 || CHAP_SUPPORT > 0
/* The name by which the peer authenticated itself to us. */
static char peer_authname[MAXNAMELEN];
#endif

/* Records which authentication operations haven't completed yet. */
static int auth_pending[NUM_PPP];

/* Set if we have successfully called login() */
static int logged_in;

/* Set if we have run the /etc/ppp/auth-up script. */
static int did_authup;

/* List of addresses which the peer may use. */
static struct wordlist *addresses[NUM_PPP];

/* Number of network protocols which we have opened. */
static int num_np_open;

/* Number of network protocols which have come up. */
static int num_np_up;

#if PAP_SUPPORT > 0 || CHAP_SUPPORT > 0
/* Set if we got the contents of passwd[] from the pap-secrets file. */
static int passwd_from_file;
#endif



/***********************************/
/*** PUBLIC FUNCTION DEFINITIONS ***/
/***********************************/
/*
 * An Open on LCP has requested a change from Dead to Establish phase.
 * Do what's necessary to bring the physical layer up.
 */
#pragma argsused
void link_required(int unit)
{
    AUTHDEBUG((LOG_INFO, "link_required: %d", unit));
}

/*
 * LCP has terminated the link; go to the Dead phase and take the
 * physical layer down.
 */
#pragma argsused
void link_terminated(int unit)
{
    AUTHDEBUG((LOG_INFO, "link_terminated: %d", unit));
    
    if (lcp_phase[unit] == PHASE_DEAD)
        return;
    if (logged_in)
        logout();
    lcp_phase[unit] = PHASE_DEAD;
    trace(LOG_NOTICE, "Connection terminated.");
}

/*
 * LCP has gone down; it will either die or try to re-establish.
 */
void link_down(int unit)
{
    int i;
    struct protent *protp;
    
    AUTHDEBUG((LOG_INFO, "link_down: %d", unit));
    if (did_authup) {
        /* XXX Do link down processing. */
        did_authup = 0;
    }
    for (i = 0; (protp = protocols[i]) != NULL; ++i) {
        if (!protp->enabled_flag)
            continue;
        if (protp->protocol != PPP_LCP && protp->lowerdown != NULL)
            (*protp->lowerdown)(unit);
        if (protp->protocol < 0xC000 && protp->close != NULL)
            (*protp->close)(unit, "LCP down");
    }
    num_np_open = 0;
    num_np_up = 0;
    if (lcp_phase[unit] != PHASE_DEAD)
        lcp_phase[unit] = PHASE_TERMINATE;
}

/*
 * The link is established.
 * Proceed to the Dead, Authenticate or Network phase as appropriate.
 */
void link_established(int unit)
{
    int auth;
    int i;
    struct protent *protp;
    lcp_options *wo = &lcp_wantoptions[unit];
    lcp_options *go = &lcp_gotoptions[unit];
#if PAP_SUPPORT > 0 || CHAP_SUPPORT > 0
    lcp_options *ho = &lcp_hisoptions[unit];
#endif
    
    AUTHDEBUG((LOG_INFO, "link_established: %d", unit));
    /*
     * Tell higher-level protocols that LCP is up.
     */
    for (i = 0; (protp = protocols[i]) != NULL; ++i)
        if (protp->protocol != PPP_LCP && protp->enabled_flag
                && protp->lowerup != NULL)
            (*protp->lowerup)(unit);
    
    if (auth_required && !(go->neg_chap || go->neg_upap)) {
        /*
         * We wanted the peer to authenticate itself, and it refused:
         * treat it as though it authenticated with PAP using a username
         * of "" and a password of "".  If that's not OK, boot it out.
         */
        if (!wo->neg_upap || !null_login(unit)) {
            trace(LOG_WARNING, "peer refused to authenticate");
            lcp_close(unit, "peer refused to authenticate");
            return;
        }
    }
    
    lcp_phase[unit] = PHASE_AUTHENTICATE;
    auth = 0;
#if CHAP_SUPPORT > 0
    if (go->neg_chap) {
        ChapAuthPeer(unit, our_name, go->chap_mdtype);
        auth |= CHAP_PEER;
    } 
#endif
#if PAP_SUPPORT > 0 && CHAP_SUPPORT > 0
    else
#endif
#if PAP_SUPPORT > 0
    if (go->neg_upap) {
        upap_authpeer(unit);
        auth |= PAP_PEER;
    }
#endif
#if CHAP_SUPPORT > 0
    if (ho->neg_chap) {
        ChapAuthWithPeer(unit, user, ho->chap_mdtype);
        auth |= CHAP_WITHPEER;
    }
#endif
#if PAP_SUPPORT > 0 && CHAP_SUPPORT > 0
    else
#endif
#if PAP_SUPPORT > 0
    if (ho->neg_upap) {
        if (passwd[0] == 0) {
            passwd_from_file = 1;
            if (!get_pap_passwd(unit))
                trace(LOG_ERR, "No secret found for PAP login");
        }
        upap_authwithpeer(unit, user, passwd);
        auth |= PAP_WITHPEER;
    }
#endif
    auth_pending[unit] = auth;
    
    if (!auth)
        network_phase(unit);
}


/*
 * The peer has failed to authenticate himself using `protocol'.
 */
#pragma argsused
void auth_peer_fail(int unit, int protocol)
{
    AUTHDEBUG((LOG_INFO, "auth_peer_fail: %d proto=%X", unit, protocol));
    /*
     * Authentication failure: take the link down
     */
    lcp_close(unit, "Authentication failed");
}


#if PAP_SUPPORT > 0 || CHAP_SUPPORT > 0
/*
 * The peer has been successfully authenticated using `protocol'.
 */
void auth_peer_success(int unit, int protocol, char *name, int namelen)
{
    int bit;
    
    AUTHDEBUG((LOG_INFO, "auth_peer_success: %d proto=%X", unit, protocol));
    switch (protocol) {
    case PPP_CHAP:
        bit = CHAP_PEER;
        break;
    case PPP_PAP:
        bit = PAP_PEER;
        break;
    default:
        trace(LOG_WARNING, "auth_peer_success: unknown protocol %x",
               protocol);
        return;
    }
    
    /*
     * Save the authenticated name of the peer for later.
     */
    if (namelen > sizeof(peer_authname) - 1)
        namelen = sizeof(peer_authname) - 1;
    BCOPY(name, peer_authname, namelen);
    peer_authname[namelen] = 0;
    
    /*
     * If there is no more authentication still to be done,
     * proceed to the network (or callback) phase.
     */
    if ((auth_pending[unit] &= ~bit) == 0)
        network_phase(unit);
}

/*
 * We have failed to authenticate ourselves to the peer using `protocol'.
 */
#pragma argsused
void auth_withpeer_fail(int unit, int protocol)
{
    int errCode = PPPERR_AUTHFAIL;
    
    AUTHDEBUG((LOG_INFO, "auth_withpeer_fail: %d proto=%X", unit, protocol));
    if (passwd_from_file)
        BZERO(passwd, MAXSECRETLEN);
    /* 
     * XXX Warning: the unit number indicates the interface which is
     * not necessarily the PPP connection.  It works here as long
     * as we are only supporting PPP interfaces.
     */
    pppIOCtl(unit, PPPCTLS_ERRCODE, &errCode);

    /*
     * We've failed to authenticate ourselves to our peer.
     * He'll probably take the link down, and there's not much
     * we can do except wait for that.
     */
}

/*
 * We have successfully authenticated ourselves with the peer using `protocol'.
 */
void auth_withpeer_success(int unit, int protocol)
{
    int bit;
    
    AUTHDEBUG((LOG_INFO, "auth_withpeer_success: %d proto=%X", unit, protocol));
    switch (protocol) {
    case PPP_CHAP:
        bit = CHAP_WITHPEER;
        break;
    case PPP_PAP:
        if (passwd_from_file)
            BZERO(passwd, MAXSECRETLEN);
        bit = PAP_WITHPEER;
        break;
    default:
        trace(LOG_WARNING, "auth_peer_success: unknown protocol %x",
               protocol);
        bit = 0;
    }
    
    /*
     * If there is no more authentication still being done,
     * proceed to the network (or callback) phase.
     */
    if ((auth_pending[unit] &= ~bit) == 0)
        network_phase(unit);
}
#endif


/*
 * np_up - a network protocol has come up.
 */
#pragma argsused
void np_up(int unit, int proto)
{
    AUTHDEBUG((LOG_INFO, "np_up: %d proto=%X", unit, proto));
    if (num_np_up == 0) {
	AUTHDEBUG((LOG_INFO, "np_up: maxconnect=%d idle_time_limit=%d",maxconnect,idle_time_limit));
        /*
         * At this point we consider that the link has come up successfully.
         */
        if (idle_time_limit > 0)
            TIMEOUT(check_idle, NULL, idle_time_limit);
        
        /*
         * Set a timeout to close the connection once the maximum
         * connect time has expired.
         */
        if (maxconnect > 0)
            TIMEOUT(connect_time_expired, 0, maxconnect);
    }
    ++num_np_up;
}

/*