/*
* 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.
*/
#ifndef lint
/* static char rcsid[] = "$Id$"; */
#endif
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <pwd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <fcntl.h>
#if defined(_PATH_LASTLOG) && defined(_linux_)
#include <lastlog.h>
#endif
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
/* #include <stbconfig.h> */
#include "pppd.h"
#include "fsm.h"
#include "lcp.h"
#include "ipcp.h"
#include "upap.h"
#include "chap.h"
#ifdef CBCP_SUPPORT
#include "cbcp.h"
#endif
#include "pathnames.h"
/* Used for storing a sequence of words. Usually malloced. */
struct wordlist {
struct wordlist *next;
char word[1];
};
/* Bits in scan_authfile return value */
#define NONWILD_SERVER 1
#define NONWILD_CLIENT 2
#define ISWILD(word) (word[0] == '*' && word[1] == 0)
#define FALSE 0
#define TRUE 1
/* The name by which the peer authenticated itself to us. */
char peer_authname[MAXNAMELEN];
/* Records which authentication operations haven't completed yet. */
static int auth_pending[NUM_PPP];
/* Set if we have successfully called plogin() */
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;
/* Set if we got the contents of passwd[] from the pap-secrets file. */
static int passwd_from_file;
/* Bits in auth_pending[] */
#define PAP_WITHPEER 1
#define PAP_PEER 2
#define CHAP_WITHPEER 4
#define CHAP_PEER 8
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 *));
static int plogin __P((char *, char *, char **, int *));
static void plogout __P((void));
static int null_login __P((int));
static int get_pap_passwd __P((char *));
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 *));
static int scan_authfile __P((FILE *, char *, char *, u_int32_t, char *,
struct wordlist **, char *));
static void free_wordlist __P((struct wordlist *));
static void auth_script __P((char *));
static void set_allowed_addrs __P((int, struct wordlist *));
/*
* An Open on LCP has requested a change from Dead to Establish phase.
* Do what's necessary to bring the physical layer up.
*/
void
link_required(unit)
int unit;
{
}
/*
* LCP has terminated the link; go to the Dead phase and take the
* physical layer down.
*/
void
link_terminated(unit)
int unit;
{
if (phase == PHASE_DEAD)
return;
if (logged_in)
plogout();
phase = PHASE_DEAD;
syslog(LOG_NOTICE, "Connection terminated.");
}
/*
* LCP has gone down; it will either die or try to re-establish.
*/
void
link_down(unit)
int unit;
{
int i;
struct protent *protp;
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 (phase != PHASE_DEAD)
phase = PHASE_TERMINATE;
}
/*
* The link is established.
* Proceed to the Dead, Authenticate or Network phase as appropriate.
*/
void
link_established(unit)
int unit;
{
int auth;
lcp_options *wo = &lcp_wantoptions[unit];
lcp_options *go = &lcp_gotoptions[unit];
lcp_options *ho = &lcp_hisoptions[unit];
int i;
struct protent *protp;
/*
* 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)) {
lcp_close(unit, "peer refused to authenticate");
return;
}
}
phase = PHASE_AUTHENTICATE;
auth = 0;
if (go->neg_chap) {
ChapAuthPeer(unit, our_name, go->chap_mdtype);
auth |= CHAP_PEER;
} else if (go->neg_upap) {
upap_authpeer(unit);
auth |= PAP_PEER;
}
if (ho->neg_chap) {
ChapAuthWithPeer(unit, user, ho->chap_mdtype);
auth |= CHAP_WITHPEER;
} else if (ho->neg_upap) {
if (passwd[0] == 0) {
passwd_from_file = 1;
get_pap_passwd(passwd);
}
upap_authwithpeer(unit, user, passwd);
auth |= PAP_WITHPEER;
}
auth_pending[unit] = auth;
if (!auth)
network_phase(unit);
}
/*
* Proceed to the network phase.
*/
static void
network_phase(unit)
int unit;
{
int i;
struct protent *protp;
lcp_options *go = &lcp_gotoptions[unit];
/*
* If the peer had to authenticate, run the auth-up script now.
*/
if ((go->neg_chap || go->neg_upap) && !did_authup) {
auth_script(_PATH_AUTHUP);
did_authup = 1;
}
#ifdef CBCP_SUPPORT
/*
* If we negotiated callback, do it now.
*/
if (go->neg_cbcp) {
phase = PHASE_CALLBACK;
(*cbcp_protent.open)(unit);
return;
}
#endif
phase = PHASE_NETWORK;
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->protocol < 0xC000 && protp->enabled_flag
&& protp->open != NULL) {
(*protp->open)(unit);
if (protp->protocol != PPP_CCP)
++num_np_open;
}
if (num_np_open == 0)
/* nothing to do */
lcp_close(0, "No network protocols running");
}
/*
* The peer has failed to authenticate himself using `protocol'.
*/
void
auth_peer_fail(unit, protocol)
int unit, protocol;
{
/*
* Authentication failure: take the link down
*/
lcp_close(unit, "Authentication failed");
}
/*
* The peer has been successfully authenticated using `protocol'.
*/
void
auth_peer_success(unit, protocol, name, namelen)
int unit, protocol;
char *name;
int namelen;
{
int bit;
switch (protocol) {
case PPP_CHAP:
bit = CHAP_PEER;
break;
case PPP_PAP:
bit = PAP_PEER;
break;
default:
syslog(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'.
*/
void
auth_withpeer_fail(unit, protocol)
int unit, protocol;
{
if (passwd_from_file)
BZERO(passwd, MAXSECRETLEN);
/*
* 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(unit, protocol)
int unit, protocol;
{
int bit;
switch (protocol) {
case PPP_CHAP:
bit = CHAP_WITHPEER;
break;
case PPP_PAP:
if (passwd_from_file)
BZERO(passwd, MAXSECRETLEN);
bit = PAP_WITHPEER;
break;
default:
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);
}
/*
* np_up - a network protocol has come up.
*/
void
np_up(unit, proto)
int unit, proto;
{
if (num_np_up == 0) {
/*
* At this point we consider that the link has come up successfully.
*/
need_holdoff = 0;
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);
/*
* Detach now, if the updetach option was given.
*/
if (nodetach == -1)
detach();
}
++num_np_up;
}
/*
* np_down - a network protocol has gone down.
*/
void
np_down(unit, proto)
int unit, proto;
{
if (--num_np_up == 0 && idle_time_limit > 0) {
UNTIMEOUT(check_idle, NULL);
}
}
/*
* np_finished - a network protocol has finished using the link.
*/
void
np_finished(unit, proto)
int unit, proto;
{
if (--num_np_open <= 0) {
/* no further use for the link: shut up shop. */
lcp_close(0, "No network protocols running");
}
}
/*
* check_idle - check whether the link has been idle for long
* enough that we can shut it down.
*/
static void
check_idle(arg)
void *arg;
{
struct ppp_idle idle;
time_t itime;
if (!get_idle_time(0, &idle))
return;
itime = MIN(idle.xmit_idle, idle.recv_idle);
if (itime >= idle_time_limit) {
/* link is idle: shut it down. */
syslog(LOG_INFO, "Terminating connection due to lack of activity.");
lcp_close(0, "Link inactive");
} else {
TIMEOUT(check_idle, NULL, idle_time_limit - itime);
}
}
/*
* connect_time_expired - log a message and close the connection.
*/
static void
connect_time_expired(arg)
void *arg;
{
syslog(LOG_INFO, "Connect time expired");
lcp_close(0, "Connect time expired"); /* Close connection */
}
/*
* auth_check_options - called to check authentication options.
*/
void
auth_check_options()
{
lcp_options *wo = &lcp_wantoptions[0];
int can_auth;
ipcp_options *ipwo = &ipcp_wantoptions[0];
u_int32_t remote;
/* Default our_name to hostname, and user to our_name */
if (our_name[0] == 0 || usehostname)
strcpy(our_name, hostname);
if (user[0] == 0)
strcpy(user, our_name);
/* If authentication is required, ask peer for CHAP or PAP. */
if (auth_required && !wo->neg_chap && !wo->neg_upap) {
wo->neg_chap = 1;
wo->neg_upap = 1;
}
/*
* Check whether we have appropriate secrets to use
* to authenticate the peer.
*/
can_auth = wo->neg_upap && (uselogin || have_pap_secret());
if (!can_auth && wo->neg_chap) {
remote = ipwo->accept_remote? 0: ipwo->hisaddr;
can_auth = have_chap_secret(remote_name, our_name, remote);
}
if (auth_required && !can_auth) {
option_error("peer authentication required but no suitable secret(s) found\n");
if (remote_name[0] == 0)
option_error("for authenticating any peer to us (%s)\n", our_name);
else
option_error("for authenticating peer %s to us (%s)\n",
remote_name, our_name);
exit(1);
}
/*
* Check whether the user tried to override certain values
* set by root.
*/
if (!auth_required && auth_req_info.priv > 0) {
if (!default_device && devnam_info.priv == 0) {
option_error("can't override device name when noauth option used");
exit(1);
}
if ((connector != NULL && connector_info.priv == 0)
|| (disconnector != NULL && disconnector_info.priv == 0)
|| (welcomer != NULL && welcomer_info.priv == 0)) {
option_error("can't override connect, disconnect or welcome");
option_error("option values when noauth option used");
exit(1);
}
}
}
/*
* auth_reset - called when LCP is starting negotiations to recheck
* authentication options, i.e. whether we have appropriate secrets
* to use for authenticating ourselves and/or the peer.
*/
void
auth_reset(unit)
int unit;
{
lcp_options *go = &lcp_gotoptions[unit];
lcp_options *ao = &lcp_allowoptions[0];
ipcp_options *ipwo = &ipcp_wantoptions[0];
u_int32_t remote;
ao->neg_upap = !refuse_pap /*&& (passwd[0] != 0 || get_pap_passwd(NULL))*/;
ao->neg_chap = !refuse_chap
&& have_chap_secret(user, remote_name, (u_int32_t)0);
if (go->neg_upap && !uselogin && !have_pap_secret())
go->neg_upap = 0;
if (go->neg_chap) {
remote = ipwo->accept_remote? 0: ipwo->hisaddr;
if (!have_chap_secret(remote_name, our_name, remote))
go->neg_chap = 0;
}
}
/*
* check_passwd - Check the user name and passwd against the PAP secrets
* file. If requested, also check against the system password database,
* and login the user if OK.
*
* returns:
* UPAP_AUTHNAK: Authentication failed.
* UPAP_AUTHACK: Authentication succeeded.
* In either case, msg points to an appropriate message.
*/
int
check_passwd(unit, auser, userlen, apasswd, passwdlen, msg, msglen)
int unit;
char *auser;
int userlen;
char *apasswd;
int passwdlen;
char **msg;
int *msglen;
{
return UPAP_AUTHNAK;
}
/*
* plogin - Check the user name and password against the system
* password database, and login the user if OK.
*
* returns:
* UPAP_AUTHNAK: Login failed.
* UPAP_AUTHACK: Login succeeded.
* In either case, msg points to an appropriate message.
*/
static int
plogin(user, passwd, msg, msglen)
char *user;
char *passwd;
char **msg;
int *msglen;
{
syslog(LOG_INFO, "user %s logged in", user);
logged_in = TRUE;
return (UPAP_AUTHACK);
}
/*
* plogout - Logout the user.
*/
static void
plogout()
{
logged_in = FALSE;
}
/*
* null_login - Check if a username of "" and a password of "" are
* acceptable, and iff so, set the list of acceptable IP addresses
* and return 1.
*/
static int
null_login(unit)
int unit;
{
return 1;
}
/*
* get_pap_passwd - get a password for authenticating ourselves with
* our peer using PAP. Returns 1 on success, 0 if no suitable password
* could be found.
*/
static int
get_pap_passwd(passwd)
char *passwd;
{
#if 0
/* XXX PPPConfiguration */
GlobalSystemStatus *stat;
stat=LockSTBSystemParam();
strncpy(passwd, stat->PPP_Password, MAXSECRETLEN);
UnlockSTBSystemParam();
#endif
return 1;
}
/*
* have_pap_secret - check whether we have a PAP file with any
* secrets that we could possibly use for authenticating the peer.
*/
static int
have_pap_secret()
{
return 1;
}
/*
* have_chap_secret - check whether we have a CHAP file with a
* secret that we could possibly use for authenticating `client'
* on `server'. Either can be the null string, meaning we don't
* know the identity yet.
*/
static int
have_chap_secret(client, server, remote)
char *client;
char *server;
u_int32_t remote;
{
return 1;
}
/*
* get_secret - open the CHAP secret file and return the secret
* for authenticating the given client on the given server.
* (We could be either client or server).
*/
int
get_secret(unit, client, server, secret, secret_len, save_addrs)
int unit;
char *client;
char *server;
char *secret;
int *secret_len;
int save_addrs;
{
#if 0
/* XXX PPPConfiguration */
int len;
GlobalSystemStatus *stat;
stat=LockSTBSystemParam();
len=strlen(stat->PPP_Password);
strcpy( secret,stat->PPP_Password);
UnlockSTBSystemParam();
*secret_len = len;
#endif
return 1;
}
/*
* set_allowed_addrs() - set the list of allowed addresses.
*/
static void
set_allowed_addrs(unit, addrs)
int unit;
struct wordlist *addrs;
{
}
/*
* auth_ip_addr - check whether the peer is authorized to use
* a given IP address. Returns 1 if authorized, 0 otherwise.
*/
int
auth_ip_addr(unit, addr)
int unit;
u_int32_t addr;
{
return ip_addr_check(addr, addresses[unit]);
}
static int
ip_addr_check(addr, addrs)
u_int32_t addr;
struct wordlist *addrs;
{
#if 0
u_int32_t a, mask, ah;
int accept;
char *ptr_word, *ptr_mask;
struct hostent *hp;
struct netent *np;
#endif
/* don't allow loopback or multicast address */
if (bad_ip_adrs(addr))
return 0;
if (addrs == NULL)
return !auth_required; /* no addresses authorized */
return 1;
}
/*
* bad_ip_adrs - return 1 if the IP address is one we don't want
* to use, such as an address in the loopback net or a multicast address.
* addr is in network byte order.
*/
int
bad_ip_adrs(addr)
u_int32_t addr;
{
addr = ntohl(addr);
return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET
|| IN_MULTICAST(addr) || IN_BADCLASS(addr);
}
/*
* check_access - complain if a secret file has too-liberal permissions.
*/
void
check_access(f, filename)
FILE *f;
char *filename;
{
}
/*
* scan_authfile - Scan an authorization file for a secret suitable
* for authenticating `client' on `server'. The return value is -1
* if no secret is found, otherwise >= 0. The return value has
* NONWILD_CLIENT set if the secret didn't have "*" for the client, and
* NONWILD_SERVER set if the secret didn't have "*" for the server.
* Any following words on the line (i.e. address authorization
* info) are placed in a wordlist and returned in *addrs.
*/
static int
scan_authfile(f, client, server, ipaddr, secret, addrs, filename)
FILE *f;
char *client;
char *server;
u_int32_t ipaddr;
char *secret;
struct wordlist **addrs;
char *filename;
{
return -1;
}
/*
* free_wordlist - release memory allocated for a wordlist.
*/
static void
free_wordlist(wp)
struct wordlist *wp;
{
struct wordlist *next;
while (wp != NULL) {
next = wp->next;
free(wp);
wp = next;
}
}
/*
* auth_script - execute a script with arguments
* interface-name peer-name real-user tty speed
*/
static void
auth_script(script)
char *script;
{
}