908 lines
20 KiB
C
908 lines
20 KiB
C
/*
|
|
* 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: auth.c,v 1.3 1995/05/30 03:51:04 rgrimes Exp $";
|
|
#endif
|
|
|
|
#include <stdio.h>
|
|
#include <stddef.h>
|
|
#include <syslog.h>
|
|
#include <pwd.h>
|
|
#include <string.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include <netdb.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
|
|
#include "ppp.h"
|
|
#include "pppd.h"
|
|
#include "fsm.h"
|
|
#include "lcp.h"
|
|
#include "upap.h"
|
|
#include "chap.h"
|
|
#include "ipcp.h"
|
|
#include "pathnames.h"
|
|
|
|
#ifdef sparc
|
|
#include <alloca.h>
|
|
#endif /*sparc*/
|
|
|
|
/* 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
|
|
|
|
extern char user[];
|
|
extern char passwd[];
|
|
extern char devname[];
|
|
extern char our_name[];
|
|
extern char remote_name[];
|
|
extern char hostname[];
|
|
extern int uselogin;
|
|
extern int usehostname;
|
|
extern int auth_required;
|
|
|
|
/* Records which authentication operations haven't completed yet. */
|
|
static int auth_pending[NPPP];
|
|
static int logged_in;
|
|
static struct wordlist *addresses[NPPP];
|
|
|
|
/* Bits in auth_pending[] */
|
|
#define UPAP_WITHPEER 1
|
|
#define UPAP_PEER 2
|
|
#define CHAP_WITHPEER 4
|
|
#define CHAP_PEER 8
|
|
|
|
/* Prototypes */
|
|
void check_access __ARGS((FILE *, char *));
|
|
|
|
static int login __ARGS((char *, char *, char **, int *));
|
|
static void logout __ARGS((void));
|
|
static int null_login __ARGS((int));
|
|
static int get_upap_passwd __ARGS((void));
|
|
static int have_upap_secret __ARGS((void));
|
|
static int have_chap_secret __ARGS((char *, char *));
|
|
static int scan_authfile __ARGS((FILE *, char *, char *, char *,
|
|
struct wordlist **, char *));
|
|
static void free_wordlist __ARGS((struct wordlist *));
|
|
|
|
extern char *crypt __ARGS((char *, char *));
|
|
|
|
/*
|
|
* 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 (logged_in)
|
|
logout();
|
|
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;
|
|
{
|
|
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];
|
|
|
|
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)) {
|
|
syslog(LOG_WARNING, "peer refused to authenticate");
|
|
lcp_close(unit);
|
|
phase = PHASE_TERMINATE;
|
|
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 |= UPAP_PEER;
|
|
}
|
|
if (ho->neg_chap) {
|
|
ChapAuthWithPeer(unit, our_name, ho->chap_mdtype);
|
|
auth |= CHAP_WITHPEER;
|
|
} else if (ho->neg_upap) {
|
|
upap_authwithpeer(unit, user, passwd);
|
|
auth |= UPAP_WITHPEER;
|
|
}
|
|
auth_pending[unit] = auth;
|
|
|
|
if (!auth) {
|
|
phase = PHASE_NETWORK;
|
|
ipcp_open(unit);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
phase = PHASE_TERMINATE;
|
|
}
|
|
|
|
/*
|
|
* The peer has been successfully authenticated using `protocol'.
|
|
*/
|
|
void
|
|
auth_peer_success(unit, protocol)
|
|
int unit, protocol;
|
|
{
|
|
int bit;
|
|
|
|
switch (protocol) {
|
|
case CHAP:
|
|
bit = CHAP_PEER;
|
|
break;
|
|
case UPAP:
|
|
bit = UPAP_PEER;
|
|
break;
|
|
default:
|
|
syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",
|
|
protocol);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If there is no more authentication still to be done,
|
|
* proceed to the network phase.
|
|
*/
|
|
if ((auth_pending[unit] &= ~bit) == 0) {
|
|
phase = PHASE_NETWORK;
|
|
ipcp_open(unit);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We have failed to authenticate ourselves to the peer using `protocol'.
|
|
*/
|
|
void
|
|
auth_withpeer_fail(unit, protocol)
|
|
int unit, protocol;
|
|
{
|
|
/*
|
|
* 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 CHAP:
|
|
bit = CHAP_WITHPEER;
|
|
break;
|
|
case UPAP:
|
|
bit = UPAP_WITHPEER;
|
|
break;
|
|
default:
|
|
syslog(LOG_WARNING, "auth_peer_success: unknown protocol %x",
|
|
protocol);
|
|
bit = 0;
|
|
}
|
|
|
|
/*
|
|
* If there is no more authentication still being done,
|
|
* proceed to the network phase.
|
|
*/
|
|
if ((auth_pending[unit] &= ~bit) == 0) {
|
|
phase = PHASE_NETWORK;
|
|
ipcp_open(unit);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* check_auth_options - called to check authentication options.
|
|
*/
|
|
void
|
|
check_auth_options()
|
|
{
|
|
lcp_options *wo = &lcp_wantoptions[0];
|
|
lcp_options *ao = &lcp_allowoptions[0];
|
|
|
|
/* 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 ourselves and/or the peer.
|
|
*/
|
|
if (ao->neg_upap && passwd[0] == 0 && !get_upap_passwd())
|
|
ao->neg_upap = 0;
|
|
if (wo->neg_upap && !uselogin && !have_upap_secret())
|
|
wo->neg_upap = 0;
|
|
if (ao->neg_chap && !have_chap_secret(our_name, remote_name))
|
|
ao->neg_chap = 0;
|
|
if (wo->neg_chap && !have_chap_secret(remote_name, our_name))
|
|
wo->neg_chap = 0;
|
|
|
|
if (auth_required && !wo->neg_chap && !wo->neg_upap) {
|
|
fprintf(stderr, "\
|
|
pppd: peer authentication required but no authentication files accessible\n");
|
|
exit(1);
|
|
}
|
|
|
|
}
|
|
|
|
|
|
/*
|
|
* 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;
|
|
{
|
|
int ret;
|
|
char *filename;
|
|
FILE *f;
|
|
struct wordlist *addrs;
|
|
char passwd[256], user[256];
|
|
char secret[MAXWORDLEN];
|
|
static int attempts = 0;
|
|
|
|
/*
|
|
* Make copies of apasswd and auser, then null-terminate them.
|
|
*/
|
|
BCOPY(apasswd, passwd, passwdlen);
|
|
passwd[passwdlen] = '\0';
|
|
BCOPY(auser, user, userlen);
|
|
user[userlen] = '\0';
|
|
|
|
/*
|
|
* Open the file of upap secrets and scan for a suitable secret
|
|
* for authenticating this user.
|
|
*/
|
|
filename = _PATH_UPAPFILE;
|
|
addrs = NULL;
|
|
ret = UPAP_AUTHACK;
|
|
f = fopen(filename, "r");
|
|
if (f == NULL) {
|
|
if (!uselogin) {
|
|
syslog(LOG_ERR, "Can't open upap password file %s: %m", filename);
|
|
ret = UPAP_AUTHNAK;
|
|
}
|
|
|
|
} else {
|
|
check_access(f, filename);
|
|
if (scan_authfile(f, user, our_name, secret, &addrs, filename) < 0
|
|
|| (secret[0] != 0 && strcmp(passwd, secret) != 0
|
|
&& strcmp(crypt(passwd, secret), secret) != 0)) {
|
|
syslog(LOG_WARNING, "upap authentication failure for %s", user);
|
|
ret = UPAP_AUTHNAK;
|
|
}
|
|
fclose(f);
|
|
}
|
|
|
|
if (uselogin && ret == UPAP_AUTHACK) {
|
|
ret = login(user, passwd, msg, msglen);
|
|
if (ret == UPAP_AUTHNAK) {
|
|
syslog(LOG_WARNING, "upap login failure for %s", user);
|
|
}
|
|
}
|
|
|
|
if (ret == UPAP_AUTHNAK) {
|
|
*msg = "Login incorrect";
|
|
*msglen = strlen(*msg);
|
|
/*
|
|
* Frustrate passwd stealer programs.
|
|
* Allow 10 tries, but start backing off after 3 (stolen from login).
|
|
* On 10'th, drop the connection.
|
|
*/
|
|
if (attempts++ >= 10) {
|
|
syslog(LOG_WARNING, "%d LOGIN FAILURES ON %s, %s",
|
|
attempts, devname, user);
|
|
quit();
|
|
}
|
|
if (attempts > 3)
|
|
sleep((u_int) (attempts - 3) * 5);
|
|
if (addrs != NULL)
|
|
free_wordlist(addrs);
|
|
|
|
} else {
|
|
attempts = 0; /* Reset count */
|
|
*msg = "Login ok";
|
|
*msglen = strlen(*msg);
|
|
if (addresses[unit] != NULL)
|
|
free_wordlist(addresses[unit]);
|
|
addresses[unit] = addrs;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* login - 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
|
|
login(user, passwd, msg, msglen)
|
|
char *user;
|
|
char *passwd;
|
|
char **msg;
|
|
int *msglen;
|
|
{
|
|
struct passwd *pw;
|
|
char *epasswd;
|
|
char *tty;
|
|
|
|
if ((pw = getpwnam(user)) == NULL) {
|
|
return (UPAP_AUTHNAK);
|
|
}
|
|
|
|
if (pw->pw_expire && time(NULL) >= pw->pw_expire)
|
|
return (UPAP_AUTHNAK);
|
|
|
|
/*
|
|
* XXX If no passwd, let them login without one.
|
|
*/
|
|
if (pw->pw_passwd == '\0') {
|
|
return (UPAP_AUTHACK);
|
|
}
|
|
|
|
epasswd = crypt(passwd, pw->pw_passwd);
|
|
if (strcmp(epasswd, pw->pw_passwd)) {
|
|
return (UPAP_AUTHNAK);
|
|
}
|
|
|
|
syslog(LOG_INFO, "user %s logged in", user);
|
|
|
|
/*
|
|
* Write a wtmp entry for this user.
|
|
*/
|
|
tty = strrchr(devname, '/');
|
|
if (tty == NULL)
|
|
tty = devname;
|
|
else
|
|
tty++;
|
|
logwtmp(tty, user, ""); /* Add wtmp login entry */
|
|
logged_in = TRUE;
|
|
|
|
return (UPAP_AUTHACK);
|
|
}
|
|
|
|
/*
|
|
* logout - Logout the user.
|
|
*/
|
|
static void
|
|
logout()
|
|
{
|
|
char *tty;
|
|
|
|
tty = strrchr(devname, '/');
|
|
if (tty == NULL)
|
|
tty = devname;
|
|
else
|
|
tty++;
|
|
logwtmp(tty, "", ""); /* Wipe out wtmp logout entry */
|
|
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;
|
|
{
|
|
char *filename;
|
|
FILE *f;
|
|
int i, ret;
|
|
struct wordlist *addrs;
|
|
char secret[MAXWORDLEN];
|
|
|
|
/*
|
|
* Open the file of upap secrets and scan for a suitable secret.
|
|
* We don't accept a wildcard client.
|
|
*/
|
|
filename = _PATH_UPAPFILE;
|
|
addrs = NULL;
|
|
f = fopen(filename, "r");
|
|
if (f == NULL)
|
|
return 0;
|
|
check_access(f, filename);
|
|
|
|
i = scan_authfile(f, "", our_name, secret, &addrs, filename);
|
|
ret = i >= 0 && (i & NONWILD_CLIENT) != 0 && secret[0] == 0;
|
|
|
|
if (ret) {
|
|
if (addresses[unit] != NULL)
|
|
free_wordlist(addresses[unit]);
|
|
addresses[unit] = addrs;
|
|
}
|
|
|
|
fclose(f);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* get_upap_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_upap_passwd()
|
|
{
|
|
char *filename;
|
|
FILE *f;
|
|
struct wordlist *addrs;
|
|
char secret[MAXWORDLEN];
|
|
|
|
filename = _PATH_UPAPFILE;
|
|
addrs = NULL;
|
|
f = fopen(filename, "r");
|
|
if (f == NULL)
|
|
return 0;
|
|
check_access(f, filename);
|
|
if (scan_authfile(f, user, remote_name, secret, NULL, filename) < 0)
|
|
return 0;
|
|
strncpy(passwd, secret, MAXSECRETLEN);
|
|
passwd[MAXSECRETLEN-1] = 0;
|
|
return 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* have_upap_secret - check whether we have a PAP file with any
|
|
* secrets that we could possibly use for authenticating the peer.
|
|
*/
|
|
static int
|
|
have_upap_secret()
|
|
{
|
|
FILE *f;
|
|
int ret;
|
|
char *filename;
|
|
|
|
filename = _PATH_UPAPFILE;
|
|
f = fopen(filename, "r");
|
|
if (f == NULL)
|
|
return 0;
|
|
|
|
ret = scan_authfile(f, NULL, our_name, NULL, NULL, filename);
|
|
fclose(f);
|
|
if (ret < 0)
|
|
return 0;
|
|
|
|
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)
|
|
char *client;
|
|
char *server;
|
|
{
|
|
FILE *f;
|
|
int ret;
|
|
char *filename;
|
|
|
|
filename = _PATH_CHAPFILE;
|
|
f = fopen(filename, "r");
|
|
if (f == NULL)
|
|
return 0;
|
|
|
|
if (client[0] == 0)
|
|
client = NULL;
|
|
else if (server[0] == 0)
|
|
server = NULL;
|
|
|
|
ret = scan_authfile(f, client, server, NULL, NULL, filename);
|
|
fclose(f);
|
|
if (ret < 0)
|
|
return 0;
|
|
|
|
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;
|
|
{
|
|
FILE *f;
|
|
int ret, len;
|
|
char *filename;
|
|
struct wordlist *addrs;
|
|
char secbuf[MAXWORDLEN];
|
|
|
|
filename = _PATH_CHAPFILE;
|
|
addrs = NULL;
|
|
secbuf[0] = 0;
|
|
|
|
f = fopen(filename, "r");
|
|
if (f == NULL) {
|
|
syslog(LOG_ERR, "Can't open chap secret file %s: %m", filename);
|
|
return 0;
|
|
}
|
|
check_access(f, filename);
|
|
|
|
ret = scan_authfile(f, client, server, secbuf, &addrs, filename);
|
|
fclose(f);
|
|
if (ret < 0)
|
|
return 0;
|
|
|
|
if (save_addrs) {
|
|
if (addresses[unit] != NULL)
|
|
free_wordlist(addresses[unit]);
|
|
addresses[unit] = addrs;
|
|
}
|
|
|
|
len = strlen(secbuf);
|
|
if (len > MAXSECRETLEN) {
|
|
syslog(LOG_ERR, "Secret for %s on %s is too long", client, server);
|
|
len = MAXSECRETLEN;
|
|
}
|
|
BCOPY(secbuf, secret, len);
|
|
*secret_len = len;
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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_long addr;
|
|
{
|
|
u_long a;
|
|
struct hostent *hp;
|
|
struct wordlist *addrs;
|
|
|
|
/* don't allow loopback or multicast address */
|
|
if (bad_ip_adrs(addr))
|
|
return 0;
|
|
|
|
if ((addrs = addresses[unit]) == NULL)
|
|
return 1; /* no restriction */
|
|
|
|
for (; addrs != NULL; addrs = addrs->next) {
|
|
/* "-" means no addresses authorized */
|
|
if (strcmp(addrs->word, "-") == 0)
|
|
break;
|
|
if ((a = inet_addr(addrs->word)) == -1) {
|
|
if ((hp = gethostbyname(addrs->word)) == NULL) {
|
|
syslog(LOG_WARNING, "unknown host %s in auth. address list",
|
|
addrs->word);
|
|
continue;
|
|
} else
|
|
a = *(u_long *)hp->h_addr;
|
|
}
|
|
if (addr == a)
|
|
return 1;
|
|
}
|
|
return 0; /* not in list => can't have it */
|
|
}
|
|
|
|
/*
|
|
* 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_long 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;
|
|
{
|
|
struct stat sbuf;
|
|
|
|
if (fstat(fileno(f), &sbuf) < 0) {
|
|
syslog(LOG_WARNING, "cannot stat secret file %s: %m", filename);
|
|
} else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
|
|
syslog(LOG_WARNING, "Warning - secret file %s has world and/or group access", 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, secret, addrs, filename)
|
|
FILE *f;
|
|
char *client;
|
|
char *server;
|
|
char *secret;
|
|
struct wordlist **addrs;
|
|
char *filename;
|
|
{
|
|
int newline, xxx;
|
|
int got_flag, best_flag;
|
|
FILE *sf;
|
|
struct wordlist *ap, *addr_list, *addr_last;
|
|
char word[MAXWORDLEN];
|
|
char atfile[MAXWORDLEN];
|
|
|
|
if (addrs != NULL)
|
|
*addrs = NULL;
|
|
addr_list = NULL;
|
|
if (!getword(f, word, &newline, filename))
|
|
return -1; /* file is empty??? */
|
|
newline = 1;
|
|
best_flag = -1;
|
|
for (;;) {
|
|
/*
|
|
* Skip until we find a word at the start of a line.
|
|
*/
|
|
while (!newline && getword(f, word, &newline, filename))
|
|
;
|
|
if (!newline)
|
|
break; /* got to end of file */
|
|
|
|
/*
|
|
* Got a client - check if it's a match or a wildcard.
|
|
*/
|
|
got_flag = 0;
|
|
if (client != NULL && strcmp(word, client) != 0 && !ISWILD(word)) {
|
|
newline = 0;
|
|
continue;
|
|
}
|
|
if (!ISWILD(word))
|
|
got_flag = NONWILD_CLIENT;
|
|
|
|
/*
|
|
* Now get a server and check if it matches.
|
|
*/
|
|
if (!getword(f, word, &newline, filename))
|
|
break;
|
|
if (newline)
|
|
continue;
|
|
if (server != NULL && strcmp(word, server) != 0 && !ISWILD(word))
|
|
continue;
|
|
if (!ISWILD(word))
|
|
got_flag |= NONWILD_SERVER;
|
|
|
|
/*
|
|
* Got some sort of a match - see if it's better than what
|
|
* we have already.
|
|
*/
|
|
if (got_flag <= best_flag)
|
|
continue;
|
|
|
|
/*
|
|
* Get the secret.
|
|
*/
|
|
if (!getword(f, word, &newline, filename))
|
|
break;
|
|
if (newline)
|
|
continue;
|
|
|
|
/*
|
|
* Special syntax: @filename means read secret from file.
|
|
*/
|
|
if (word[0] == '@') {
|
|
strcpy(atfile, word+1);
|
|
if ((sf = fopen(atfile, "r")) == NULL) {
|
|
syslog(LOG_WARNING, "can't open indirect secret file %s",
|
|
atfile);
|
|
continue;
|
|
}
|
|
check_access(sf, atfile);
|
|
if (!getword(sf, word, &xxx, atfile)) {
|
|
syslog(LOG_WARNING, "no secret in indirect secret file %s",
|
|
atfile);
|
|
fclose(sf);
|
|
continue;
|
|
}
|
|
fclose(sf);
|
|
}
|
|
if (secret != NULL)
|
|
strcpy(secret, word);
|
|
|
|
best_flag = got_flag;
|
|
|
|
/*
|
|
* Now read address authorization info and make a wordlist.
|
|
*/
|
|
if (addr_list)
|
|
free_wordlist(addr_list);
|
|
addr_list = addr_last = NULL;
|
|
for (;;) {
|
|
if (!getword(f, word, &newline, filename) || newline)
|
|
break;
|
|
ap = (struct wordlist *) malloc(sizeof(struct wordlist)
|
|
+ strlen(word));
|
|
if (ap == NULL)
|
|
novm("authorized addresses");
|
|
ap->next = NULL;
|
|
strcpy(ap->word, word);
|
|
if (addr_list == NULL)
|
|
addr_list = ap;
|
|
else
|
|
addr_last->next = ap;
|
|
addr_last = ap;
|
|
}
|
|
if (!newline)
|
|
break;
|
|
}
|
|
|
|
if (addrs != NULL)
|
|
*addrs = addr_list;
|
|
else if (addr_list != NULL)
|
|
free_wordlist(addr_list);
|
|
|
|
return best_flag;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
}
|