/*
* auth.c - PPP authentication and phase control.
*
* Copyright (c) 1993-2002 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 3. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS 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.
*
* Derived from main.c, which is:
*
* 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: auth.c,v 1.117 2008/07/01 12:27:56 paulus Exp $"
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <pwd.h>
#include <grp.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <utmp.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>
#ifdef HAS_SHADOW
#include <shadow.h>
#ifndef PW_PPP
#define PW_PPP PW_LOGIN
#endif
#endif
#include <time.h>
#include "pppd.h"
#include "fsm.h"
#include "lcp.h"
#include "ccp.h"
#include "ecp.h"
#include "ipcp.h"
#include "upap.h"
#include "chap-new.h"
#include "eap.h"
#ifdef CBCP_SUPPORT
#include "cbcp.h"
#endif
#include "pathnames.h"
#include "session.h"
static const char rcsid[] = RCSID;
/* Bits in scan_authfile return value */
#define NONWILD_SERVER 1
#define NONWILD_CLIENT 2
#define ISWILD(word) (word[0] == '*' && word[1] == 0)
/* 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];
/* Records which authentication operations have been completed. */
int auth_done[NUM_PPP];
/* List of addresses which the peer may use. */
static struct permitted_ip *addresses[NUM_PPP];
/* Wordlist giving addresses which the peer may use
without authenticating itself. */
static struct wordlist *noauth_addrs;
/* Remote telephone number, if available */
char remote_number[MAXNAMELEN];
/* Wordlist giving remote telephone numbers which may connect. */
static struct wordlist *permitted_numbers;
/* Extra options to apply, from the secrets file entry for the peer. */
static struct wordlist *extra_options;
/* 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;
/* Set if we require authentication only because we have a default route. */
static bool default_auth;
/* Hook to enable a plugin to control the idle time limit */
int (*idle_time_hook) __P((struct ppp_idle *)) = NULL;
/* Hook for a plugin to say whether we can possibly authenticate any peer */
int (*pap_check_hook) __P((void)) = NULL;
/* Hook for a plugin to check the PAP user and password */
int (*pap_auth_hook) __P((char *user, char *passwd, char **msgp,
struct wordlist **paddrs,
struct wordlist **popts)) = NULL;
/* Hook for a plugin to know about the PAP user logout */
void (*pap_logout_hook) __P((void)) = NULL;
/* Hook for a plugin to get the PAP password for authenticating us */
int (*pap_passwd_hook) __P((char *user, char *passwd)) = NULL;
/* Hook for a plugin to say if we can possibly authenticate a peer using CHAP */
int (*chap_check_hook) __P((void)) = NULL;
/* Hook for a plugin to get the CHAP password for authenticating us */
int (*chap_passwd_hook) __P((char *user, char *passwd)) = NULL;
/* Hook for a plugin to say whether it is OK if the peer
refuses to authenticate. */
int (*null_auth_hook) __P((struct wordlist **paddrs,
struct wordlist **popts)) = NULL;
int (*allowed_address_hook) __P((u_int32_t addr)) = NULL;
#ifdef HAVE_MULTILINK
/* Hook for plugin to hear when an interface joins a multilink bundle */
void (*multilink_join_hook) __P((void)) = NULL;
#endif
/* A notifier for when the peer has authenticated itself,
and we are proceeding to the network phase. */
struct notifier *auth_up_notifier = NULL;
/* A notifier for when the link goes down. */
struct notifier *link_down_notifier = NULL;
/*
* This is used to ensure that we don't start an auth-up/down
* script while one is already running.
*/
enum script_state {
s_down,
s_up
};
static enum script_state auth_state = s_down;
static enum script_state auth_script_state = s_down;
static pid_t auth_script_pid = 0;
/*
* Option variables.
*/
bool uselogin = 0; /* Use /etc/passwd for checking PAP */
bool session_mgmt = 0; /* Do session management (login records) */
bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */
bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */
bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */
bool refuse_eap = 0; /* Don't wanna auth. ourselves with EAP */
#ifdef CHAPMS
bool refuse_mschap = 0; /* Don't wanna auth. ourselves with MS-CHAP */
bool refuse_mschap_v2 = 0; /* Don't wanna auth. ourselves with MS-CHAPv2 */
#else
bool refuse_mschap = 1; /* Don't wanna auth. ourselves with MS-CHAP */
bool refuse_mschap_v2 = 1; /* Don't wanna auth. ourselves with MS-CHAPv2 */
#endif
bool usehostname = 0; /* Use hostname for our_name */
bool auth_required = 0; /* Always require authentication from peer */
bool allow_any_ip = 0; /* Allow peer to use any IP address */
bool explicit_remote = 0; /* User specified explicit remote name */
bool explicit_user = 0; /* Set if "user" option supplied */
bool explicit_passwd = 0; /* Set if "password" option supplied */
char remote_name[MAXNAMELEN]; /* Peer's name for authentication */
static char *uafname; /* name of most recent +ua file */
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 null_login __P((int));
static int get_pap_passwd __P((char *));
static int have_pap_secret __P((int *));
static int have_chap_secret __P((char *, char *, int, int *));
static int have_srp_secret __P((char *client, char *server, int need_ip,
int *lacks_ipp));
static int ip_addr_check __P((u_int32_t, struct permitted_ip *));
static int scan_authfile __P((FILE *, char *, char *, char *,
struct wordlist **, struct wordlist **,
char *, int));
static void free_wordlist __P((struct wordlist *));
static void auth_script __P((char *));
static void auth_script_done __P((void *));
static void set_allowed_addrs __P((int, struct wordlist *, struct wordlist *));
static int some_ip_ok __P((struct wordlist *));
static int setupapfile __P((char **));
static int privgroup __P((char **));
static int set_noauth_addr __P((char **));
static int set_permitted_number __P((char **));
static void check_access __P((FILE *, char *));
static int wordlist_count __P((struct wordlist *));
#ifdef MAXOCTETS
static void check_maxoctets __P((void *));
#endif
/*
* Authentication-related options.
*/
option_t auth_options[] = {
{ "auth", o_bool, &auth_required,
"Require authentication from peer", OPT_PRIO | 1 },
{ "noauth", o_bool, &auth_required,
"Don't require peer to authenticate", OPT_PRIOSUB | OPT_PRIV,
&allow_any_ip },
{ "require-pap", o_bool, &lcp_wantoptions[0].neg_upap,
"Require PAP authentication from peer",
OPT_PRIOSUB | 1, &auth_required },
{ "+pap", o_bool, &lcp_wantoptions[0].neg_upap,
"Require PAP authentication from peer",
OPT_ALIAS | OPT_PRIOSUB | 1, &auth_required },
{ "require-chap", o_bool, &auth_required,
"Require CHAP authentication from peer",
OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
&lcp_wantoptions[0].chap_mdtype },
{ "+chap", o_bool, &auth_required,
"Require CHAP authentication from peer",
OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MD5,
&lcp_wantoptions[0].chap_mdtype },
#ifdef CHAPMS
{ "require-mschap", o_bool, &auth_required,
"Require MS-CHAP authentication from peer",
OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
&lcp_wantoptions[0].chap_mdtype },
{ "+mschap", o_bool, &auth_required,
"Require MS-CHAP authentication from peer",
OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT,
&lcp_wantoptions[0].chap_mdtype },
{ "require-mschap-v2", o_bool, &auth_required,
"Require MS-CHAPv2 authentication from peer",
OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
&lcp_wantoptions[0].chap_mdtype },
{ "+mschap-v2", o_bool, &auth_required,
"Require MS-CHAPv2 authentication from peer",
OPT_ALIAS | OPT_PRIOSUB | OPT_A2OR | MDTYPE_MICROSOFT_V2,
&lcp_wantoptions[0].chap_mdtype },
#endif
{ "refuse-pap", o_bool, &refuse_pap,
"Don't agree to auth to peer with PAP", 1 },
{ "-pap", o_bool, &refuse_pap,
"Don't allow PAP authentication with peer", OPT_ALIAS | 1 },
{ "refuse-chap", o_bool, &refuse_chap,
"Don't agree to auth to peer with CHAP",
OPT_A2CLRB | MDTYPE_MD5,
&lcp_allowoptions[0].chap_mdtype },
{ "-chap", o_bool, &refuse_chap,
"Don't allow CHAP authentication with peer",
OPT_ALIAS | OPT_A2CLRB | MDTYPE_MD5,
&lcp_allowoptions[0].chap_mdtype },
#ifdef CHAPMS
{ "refuse-mschap", o_bool, &refuse_mschap,
"Don't agree to auth to peer with MS-CHAP",
OPT_A2CLRB | MDTYPE_MICROSOFT,
&lcp_allowoptions[0].chap_mdtype },
{ "-mschap", o_bool, &refuse_mschap,
"Don't allow MS-CHAP authentication with peer",
OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT,
&lcp_allowoptions[0].chap_mdtype },
{ "refuse-mschap-v2", o_bool, &refuse_mschap_v2,
"Don't agree to auth to peer with MS-CHAPv2",
OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
&lcp_allowoptions[0].chap_mdtype },
{ "-mschap-v2", o_bool, &refuse_mschap_v2,
"Don't allow MS-CHAPv2 authentication with peer",
OPT_ALIAS | OPT_A2CLRB | MDTYPE_MICROSOFT_V2,
&lcp_allowoptions[0].chap_mdtype },
#endif
{ "require-eap", o_bool, &lcp_wantoptions[0].neg_eap,
"Require EAP authentication from peer", OPT_PRIOSUB | 1,
&auth_required },
{ "refuse-eap", o_bool, &refuse_eap,
"Don't agree to authenticate to peer with EAP", 1 },
{ "name", o_string, our_name,
"Set local name for authentication",
OPT_PRIO | OPT_PRIV | OPT_STATIC, NULL, MAXNAMELEN },
{ "+ua", o_special, (void *)setupapfile,
"Get PAP user and password from file",
OPT_PRIO | OPT_A2STRVAL, &uafname },
{ "user", o_string, user,
"Set name for auth with peer", OPT_PRIO | OPT_STATIC,
&explicit_user, MAXNAMELEN },
{ "password", o_string, passwd,
"Password for authenticating us to the peer",
OPT_PRIO | OPT_STATIC | OPT_HIDE,
&explicit_passwd, MAXSECRETLEN },
{ "usehostname", o_bool, &usehostname,
"Must use hostname for authentication", 1 },
{ "remotename", o_string, remote_name,
"Set remote name for authentication", OPT_PRIO | OPT_STATIC,
&explicit_remote, MAXNAMELEN },
{ "login", o_bool, &uselogin,
"Use system password database for PAP", OPT_A2COPY | 1 ,
&session_mgmt },
{ "enable-session", o_bool, &session_mgmt,
"Enable session accounting for remote peers", OPT_PRIV | 1 },
{ "papcrypt", o_bool, &cryptpap,
"PAP passwords are encrypted", 1 },
{ "privgroup", o_special, (void *)privgroup,
"Allow group members to use privileged options", OPT_PRIV | OPT_A2LIST },
{ "allow-ip", o_special, (void *)set_noauth_addr,
"Set IP address(es) which can be used without authentication",
OPT_PRIV | OPT_A2LIST },
{ "remotenumber", o_string, remote_number,
"Set remote telephone number for authentication", OPT_PRIO | OPT_STATIC,
NULL, MAXNAMELEN },
{ "allow-number", o_special, (void *)set_permitted_number,
"Set telephone number(s) which are allowed to connect",
OPT_PRIV | OPT_A2LIST },
{ NULL }
};
/*
* setupapfile - specifies UPAP info for authenticating with peer.
*/
static int
setupapfile(argv)
char **argv;
{
FILE *ufile;
int l;
uid_t euid;
char u[MAXNAMELEN], p[MAXSECRETLEN];
char *fname;
lcp_allowoptions[0].neg_upap = 1;
/* open user info file */
fname = strdup(*argv);
if (fname == NULL)
novm("+ua file name");
euid = geteuid();
if (seteuid(getuid()) == -1) {
option_error("unable to reset uid before opening %s: %m", fname);
return 0;
}
ufile = fopen(fname, "r");
if (seteuid(euid) == -1)
fatal("unable to regain privileges: %m");
if (ufile == NULL) {
option_error("unable to open user login data file %s", fname);
return 0;
}
check_access(ufile, fname);
uafname = fname;
/* get username */
if (fgets(u, MAXNAMELEN - 1, ufile) == NULL
|| fgets(p, MAXSECRETLEN - 1, ufile) == NULL) {
fclose(ufile);
option_error("unable to read user login data file %s", fname);
return 0;
}
fclose(ufile);
/* get rid of newlines */
l = strlen(u);
if (l > 0 && u[l-1] == '\n')
u[l-1] = 0;
l = strlen(p);
if (l > 0 && p[l-1] == '\n')
p[l-1] = 0;
if (override_value("user", option_priority, fname)) {
strlcpy(user, u, sizeof(user));
explicit_user = 1;
}
if (override_value("passwd", option_priority, fname)) {
strlcpy(passwd, p, sizeof(passwd));
explicit_passwd = 1;
}
return (1);
}
/*
* privgroup - allow members of the group to have privileged access.
*/
static int
privgroup(argv)
char **argv;
{
struct group *g;
int i;
g = getgrnam(*argv);
if (g == 0) {
option_error("group %s is unknown", *argv);
return 0;
}
for (i = 0; i < ngroups; ++i) {
if (groups[i] == g->gr_gid) {
privileged = 1;
break;
}
}
return 1;
}
/*
* set_noauth_addr - set address(es) that can be used without authentication.
* Equivalent to specifying an entry like `"" * "" addr' in pap-secrets.
*/
static int
set_noauth_addr(argv)
char **argv;
{
char *addr = *argv;
int l = strlen(addr) + 1;
struct wordlist *wp;
wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
if (wp == NULL)
novm("allow-ip argument");
wp->word = (char *) (wp + 1);
wp->next = noauth_addrs;
BCOPY(addr, wp->word, l);
noauth_addrs = wp;
return 1;
}
/*
* set_permitted_number - set remote telephone number(s) that may connect.
*/
static int
set_permitted_number(argv)
char **argv;
{
char *number = *argv;
int l = strlen(number) + 1;
struct wordlist *wp;
wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
if (wp == NULL)
novm("allow-number argument");
wp->word = (char *) (wp + 1);
wp->next = permitted_numbers;
BCOPY(number, wp->word, l);
permitted_numbers = wp;
return 1;
}
/*
* An Open on LCP has requested a change from Dead to Establish phase.
*/
void
link_required(unit)
int unit;
{
}
/*
* Bring the link up to the point of being able to do ppp.
*/
void start_link(unit)
int unit;
{
status = EXIT_CONNECT_FAILED;
new_phase(PHASE_SERIALCONN);
hungup = 0;
devfd = the_channel->connect();
if (devfd < 0)
goto fail;
/* set up the serial device as a ppp interface */
/*
* N.B. we used to do tdb_writelock/tdb_writeunlock around this
* (from establish_ppp to set_ifunit). However, we won't be
* doing the set_ifunit in multilink mode, which is the only time
* we need the atomicity that the tdb_writelock/tdb_writeunlock
* gives us. Thus we don't need the tdb_writelock/tdb_writeunlock.
*/
fd_ppp = the_channel->establish_ppp(devfd);
if (fd_ppp < 0) {
status = EXIT_FATAL_ERROR;
goto disconnect;
}
if (!demand && ifunit >= 0)
set_ifunit(1);
/*
* Start opening the connection and wait for
* incoming events (reply, timeout, etc.).
*/
if (ifunit >= 0)
notice("Connect: %s <--> %s", ifname, ppp_devnam);
else
notice("Starting negotiation on %s", ppp_devnam);
add_fd(fd_ppp);
status = EXIT_NEGOTIATION_FAILED;
new_phase(PHASE_ESTABLISH);
lcp_lowerup(0);
return;
disconnect:
new_phase(PHASE_DISCONNECT);
if (the_channel->disconnect)
the_channel->disconnect();
fail:
new_phase(PHASE_DEAD);
if (the_channel->cleanup)
(*the_channel->cleanup)();
}
/*
* 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 || phase == PHASE_MASTER)
return;
new_phase(PHASE_DISCONNECT);
if (pap_logout_hook) {
pap_logout_hook();
}
session_end(devnam);
if (!doing_multilink) {
notice("Connection terminated.");
print_link_stats();
} else
notice("Link terminated.");
/*
* Delete pid files before disestablishing ppp. Otherwise it
* can happen that another pppd gets the same unit and then
* we delete its pid file.
*/
if (!doing_multilink && !demand)
remove_pidfiles();
/*
* If we may want to bring the link up again, transfer
* the ppp unit back to the loopback. Set the
* real serial device back to its normal mode of operation.
*/
if (fd_ppp >= 0) {
remove_fd(fd_ppp);
clean_check();
the_channel->disestablish_ppp(devfd);
if (doing_multilink)
mp_exit_bundle();
fd_ppp = -1;
}
if (!hungup)
lcp_lowerdown(0);
if (!doing_multilink && !demand)
script_unsetenv("IFNAME");
/*
* Run disconnector script, if requested.
* XXX we may not be able to do this if the line has hung up!
*/
if (devfd >= 0 && the_channel->disconnect) {
the_channel->disconnect();
devfd = -1;
}
if (the_channel->cleanup)
(*the_channel->cleanup)();
if (doing_multilink && multilink_master) {
if (!bundle_terminating) {
new_phase(PHASE_MASTER);
if (master_detach && !detached)
detach();
} else
mp_bundle_terminated();
} else
new_phase(PHASE_DEAD);
}
/*
* LCP has gone down; it will either die or try to re-establish.
*/
void
link_down(unit)
int unit;
{
if (auth_state != s_down) {
notify(link_down_notifier, 0);
auth_state = s_down;
if (auth_script_state == s_up && auth_script_pid == 0) {
update_link_stats(unit);
auth_script_state = s_down;
auth_script(_PATH_AUTHDOWN);
}
}
if (!doing_multilink) {
upper_layers_down(unit);
if (phase != PHASE_DEAD && phase != PHASE_MASTER)
new_phase(PHASE_ESTABLISH);
}
/* XXX if doing_multilink, should do something to stop
network-layer traffic on the link */
}
void upper_layers_down(int unit)
{
int i;
struct protent *protp;
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;
}
/*
* 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.
*/
if (!doing_multilink) {
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 && noauth_addrs != NULL)
set_allowed_addrs(unit, NULL, NULL);
if (auth_required && !(go->neg_upap || go->neg_chap || go->neg_eap)) {
/*
* We wanted the peer to authenticate itself, and it refused:
* if we have some address(es) it can use without auth, fine,
* otherwise 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 (noauth_addrs != NULL) {
set_allowed_addrs(unit, NULL, NULL);
} else if (!wo->neg_upap || uselogin || !null_login(unit)) {
warn("peer refused to authenticate: terminating link");
status = EXIT_PEER_AUTH_FAILED;
lcp_close(unit, "peer refused to authenticate");
return;
}
}
new_phase(PHASE_AUTHENTICATE);
auth = 0;
if (go->neg_eap) {
eap_authpeer(unit, our_name);
auth |= EAP_PEER;
} else if (go->neg_chap) {
chap_auth_peer(unit, our_name, CHAP_DIGEST(go->chap_mdtype));
auth |= CHAP_PEER;
} else if (go->neg_upap) {
upap_authpeer(unit);
auth |= PAP_PEER;
}
if (ho->neg_eap) {
eap_authwithpeer(unit, user);
auth |= EAP_WITHPEER;
} else if (ho->neg_chap) {
chap_auth_with_peer(unit, user, CHAP_DIGEST(ho->chap_mdtype));
auth |= CHAP_WITHPEER;
} else if (ho->neg_upap) {
/* If a blank password was explicitly given as an option, trust
the user and don't try to look up one. */
if (passwd[0] == 0 && !explicit_passwd) {
passwd_from_file = 1;
if (!get_pap_passwd(passwd))
error("No secret found for PAP login");
}
upap_authwithpeer(unit, user, passwd);
auth |= PAP_WITHPEER;
}
auth_pending[unit] = auth;
auth_done[unit] = 0;
if (!auth)
network_phase(unit);
}
/*
* Proceed to the network phase.
*/
static void
network_phase(unit)
int unit;
{
lcp_options *go = &lcp_gotoptions[unit];
/* Log calling number. */
if (*remote_number)
notice("peer from calling number %q authorized", remote_number);
/*
* If the peer had to authenticate, run the auth-up script now.
*/
if (go->neg_chap || go->neg_upap || go->neg_eap) {
notify(auth_up_notifier, 0);
auth_state = s_up;
if (auth_script_state == s_down && auth_script_pid == 0) {
auth_script_state = s_up;
auth_script(_PATH_AUTHUP);
}
}
#ifdef CBCP_SUPPORT
/*
* If we negotiated callback, do it now.
*/
if (go->neg_cbcp) {
new_phase(PHASE_CALLBACK);
(*cbcp_protent.open)(unit);
return;
}
#endif
/*
* Process extra options from the secrets file
*/
if (extra_options) {
options_from_list(extra_options, 1);
free_wordlist(extra_options);
extra_options = 0;
}
start_networks(unit);
}
void
start_networks(unit)
int unit;
{
int i;
struct protent *protp;
int ecp_required, mppe_required;
new_phase(PHASE_NETWORK);
#ifdef HAVE_MULTILINK
if (multilink) {
if (mp_join_bundle()) {
if (multilink_join_hook)
(*multilink_join_hook)();
if (updetach && !nodetach)
detach();
return;
}
}
#endif /* HAVE_MULTILINK */
#ifdef PPP_FILTER
if (!demand)
set_filters(&pass_filter, &active_filter);
#endif
/* Start CCP and ECP */
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if ((protp->protocol == PPP_ECP || protp->protocol == PPP_CCP)
&& protp->enabled_flag && protp->open != NULL)
(*protp->open)(0);
/*
* Bring up other network protocols iff encryption is not required.
*/
ecp_required = ecp_gotoptions[unit].required;
mppe_required = ccp_gotoptions[unit].mppe;
if (!ecp_required && !mppe_required)
continue_networks(unit);
}
void
continue_networks(unit)
int unit;
{
int i;
struct protent *protp;
/*
* Start the "real" network protocols.
*/
for (i = 0; (protp = protocols[i]) != NULL; ++i)
if (protp->protocol < 0xC000
&& protp->protocol != PPP_CCP && protp->protocol != PPP_ECP
&& protp->enabled_flag && protp->open != NULL) {
(*protp->open)(0);
++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
*/
status = EXIT_PEER_AUTH_FAILED;
lcp_close(unit, "Authentication failed");
}
/*
* The peer has been successfully authenticated using `protocol'.
*/
void
auth_peer_success(unit, protocol, prot_flavor, name, namelen)
int unit, protocol, prot_flavor;
char *name;
int namelen;
{
int bit;
switch (protocol) {
case PPP_CHAP:
bit = CHAP_PEER;
switch (prot_flavor) {
case CHAP_MD5:
bit |= CHAP_MD5_PEER;
break;
#ifdef CHAPMS
case CHAP_MICROSOFT:
bit |= CHAP_MS_PEER;
break;
case CHAP_MICROSOFT_V2:
bit |= CHAP_MS2_PEER;
break;
#endif
}
break;
case PPP_PAP:
bit = PAP_PEER;
break;
case PPP_EAP:
bit = EAP_PEER;
break;
default:
warn("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;
script_setenv("PEERNAME", peer_authname, 0);
/* Save the authentication method for later. */
auth_done[unit] |= bit;
/*
* 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.
* Some servers keep sending CHAP challenges, but there
* is no point in persisting without any way to get updated
* authentication secrets.
*/
status = EXIT_AUTH_TOPEER_FAILED;
lcp_close(unit, "Failed to authenticate ourselves to peer");
}
/*
* We have successfully authenticated ourselves with the peer using `protocol'.
*/
void
auth_withpeer_success(unit, protocol, prot_flavor)
int unit, protocol, prot_flavor;
{
int bit;
const char *prot = "";
switch (protocol) {
case PPP_CHAP:
bit = CHAP_WITHPEER;
prot = "CHAP";
switch (prot_flavor) {
case CHAP_MD5:
bit |= CHAP_MD5_WITHPEER;
break;
#ifdef CHAPMS
case CHAP_MICROSOFT:
bit |= CHAP_MS_WITHPEER;
break;
case CHAP_MICROSOFT_V2:
bit |= CHAP_MS2_WITHPEER;
break;
#endif
}
break;
case PPP_PAP:
if (passwd_from_file)
BZERO(passwd, MAXSECRETLEN);
bit = PAP_WITHPEER;
prot = "PAP";
break;
case PPP_EAP:
bit = EAP_WITHPEER;
prot = "EAP";
break;
default:
warn("auth_withpeer_success: unknown protocol %x", protocol);
bit = 0;
}
notice("%s authentication succeeded", prot);
/* Save the authentication method for later. */
auth_done[unit] |= bit;
/*
* 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;
{
int tlim;
if (num_np_up == 0) {
/*
* At this point we consider that the link has come up successfully.
*/
status = EXIT_OK;
unsuccess = 0;
new_phase(PHASE_RUNNING);
if (idle_time_hook != 0)
tlim = (*idle_time_hook)(NULL);
else
tlim = idle_time_limit;
if (tlim > 0)
TIMEOUT(check_idle, NULL, tlim);
/*
* Set a timeout to close the connection once the maximum
* connect time has expired.
*/
if (maxconnect > 0)
TIMEOUT(connect_time_expired, 0, maxconnect);
#ifdef MAXOCTETS
if (maxoctets > 0)
TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
#endif
/*
* Detach now, if the updetach option was given.
*/
if (updetach && !nodetach)
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) {
UNTIMEOUT(check_idle, NULL);
UNTIMEOUT(connect_time_expired, NULL);
#ifdef MAXOCTETS
UNTIMEOUT(check_maxoctets, NULL);
#endif
new_phase(PHASE_NETWORK);
}
}
/*
* 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");
}
}
#ifdef MAXOCTETS
static void
check_maxoctets(arg)
void *arg;
{
unsigned int used;
update_link_stats(ifunit);
link_stats_valid=0;
switch(maxoctets_dir) {
case PPP_OCTETS_DIRECTION_IN:
used = link_stats.bytes_in;
break;
case PPP_OCTETS_DIRECTION_OUT:
used = link_stats.bytes_out;
break;
case PPP_OCTETS_DIRECTION_MAXOVERAL:
case PPP_OCTETS_DIRECTION_MAXSESSION:
used = (link_stats.bytes_in > link_stats.bytes_out) ? link_stats.bytes_in : link_stats.bytes_out;
break;
default:
used = link_stats.bytes_in+link_stats.bytes_out;
break;
}
if (used > maxoctets) {
notice("Traffic limit reached. Limit: %u Used: %u", maxoctets, used);
status = EXIT_TRAFFIC_LIMIT;
lcp_close(0, "Traffic limit");
need_holdoff = 0;
} else {
TIMEOUT(check_maxoctets, NULL, maxoctets_timeout);
}
}
#endif
/*
* 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;
int tlim;
if (!get_idle_time(0, &idle))
return;
if (idle_time_hook != 0) {
tlim = idle_time_hook(&idle);
} else {
itime = MIN(idle.xmit_idle, idle.recv_idle);
tlim = idle_time_limit - itime;
}
if (tlim <= 0) {
/* link is idle: shut it down. */
notice("Terminating connection due to lack of activity.");
status = EXIT_IDLE_TIMEOUT;
lcp_close(0, "Link inactive");
need_holdoff = 0;
} else {
TIMEOUT(check_idle, NULL, tlim);
}
}
/*
* connect_time_expired - log a message and close the connection.
*/
static void
connect_time_expired(arg)
void *arg;
{
info("Connect time expired");
status = EXIT_CONNECT_TIME;
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;
int lacks_ip;
/* Default our_name to hostname, and user to our_name */
if (our_name[0] == 0 || usehostname)
strlcpy(our_name, hostname, sizeof(our_name));
/* If a blank username was explicitly given as an option, trust
the user and don't use our_name */
if (user[0] == 0 && !explicit_user)
strlcpy(user, our_name, sizeof(user));
/*
* If we have a default route, require the peer to authenticate
* unless the noauth option was given or the real user is root.
*/
if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) {
auth_required = 1;
default_auth = 1;
}
/* If we selected any CHAP flavors, we should probably negotiate it. :-) */
if (wo->chap_mdtype)
wo->neg_chap = 1;
/* If authentication is required, ask peer for CHAP, PAP, or EAP. */
if (auth_required) {
allow_any_ip = 0;
if (!wo->neg_chap && !wo->neg_upap && !wo->neg_eap) {
wo->neg_chap = chap_mdtype_all != MDTYPE_NONE;
wo->chap_mdtype = chap_mdtype_all;
wo->neg_upap = 1;
wo->neg_eap = 1;
}
} else {
wo->neg_chap = 0;
wo->chap_mdtype = MDTYPE_NONE;
wo->neg_upap = 0;
wo->neg_eap = 0;
}
/*
* Check whether we have appropriate secrets to use
* to authenticate the peer. Note that EAP can authenticate by way
* of a CHAP-like exchanges as well as SRP.
*/
lacks_ip = 0;
can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip));
if (!can_auth && (wo->neg_chap || wo->neg_eap)) {
can_auth = have_chap_secret((explicit_remote? remote_name: NULL),
our_name, 1, &lacks_ip);
}
if (!can_auth && wo->neg_eap) {
can_auth = have_srp_secret((explicit_remote? remote_name: NULL),
our_name, 1, &lacks_ip);
}
if (auth_required && !can_auth && noauth_addrs == NULL) {
if (default_auth) {
option_error(
"By default the remote system is required to authenticate itself");
option_error(
"(because this system has a default route to the internet)");
} else if (explicit_remote)
option_error(
"The remote system (%s) is required to authenticate itself",
remote_name);
else
option_error(
"The remote system is required to authenticate itself");
option_error(
"but I couldn't find any suitable secret (password) for it to use to do so.");
if (lacks_ip)
option_error(
"(None of the available passwords would let it use an IP address.)");
exit(1);
}
/*
* Early check for remote number authorization.
*/
if (!auth_number()) {
warn("calling number %q is not authorized", remote_number);
exit(EXIT_CNID_AUTH_FAILED);
}
}
/*
* 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[unit];
int hadchap;
hadchap = -1;
ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL));
ao->neg_chap = (!refuse_chap || !refuse_mschap || !refuse_mschap_v2)
&& (passwd[0] != 0 ||
(hadchap = have_chap_secret(user, (explicit_remote? remote_name:
NULL), 0, NULL)));
ao->neg_eap = !refuse_eap && (
passwd[0] != 0 ||
(hadchap == 1 || (hadchap == -1 && have_chap_secret(user,
(explicit_remote? remote_name: NULL), 0, NULL))) ||
have_srp_secret(user, (explicit_remote? remote_name: NULL), 0, NULL));
hadchap = -1;
if (go->neg_upap && !uselogin && !have_pap_secret(NULL))
go->neg_upap = 0;
if (go->neg_chap) {
if (!(hadchap = have_chap_secret((explicit_remote? remote_name: NULL),
our_name, 1, NULL)))
go->neg_chap = 0;
}
if (go->neg_eap &&
(hadchap == 0 || (hadchap == -1 &&
!have_chap_secret((explicit_remote? remote_name: NULL), our_name,
1, NULL))) &&
!have_srp_secret((explicit_remote? remote_name: NULL), our_name, 1,
NULL))
go->neg_eap = 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)
int unit;
char *auser;
int userlen;
char *apasswd;
int passwdlen;
char **msg;
{
#if defined(__ANDROID__)
return UPAP_AUTHNAK;
#else
int ret;
char *filename;
FILE *f;
struct wordlist *addrs = NULL, *opts = NULL;
char passwd[256], user[256];
char secret[MAXWORDLEN];
static int attempts = 0;
/*
* Make copies of apasswd and auser, then null-terminate them.
* If there are unprintable characters in the password, make
* them visible.
*/
slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd);
slprintf(user, sizeof(user), "%.*v", userlen, auser);
*msg = "";
/*
* Check if a plugin wants to handle this.
*/
if (pap_auth_hook) {
ret = (*pap_auth_hook)(user, passwd, msg, &addrs, &opts);
if (ret >= 0) {
/* note: set_allowed_addrs() saves opts (but not addrs):
don't free it! */
if (ret)
set_allowed_addrs(unit, addrs, opts);
else if (opts != 0)
free_wordlist(opts);
if (addrs != 0)
free_wordlist(addrs);
BZERO(passwd, sizeof(passwd));
return ret? UPAP_AUTHACK: UPAP_AUTHNAK;
}
}
/*
* Open the file of pap secrets and scan for a suitable secret
* for authenticating this user.
*/
filename = _PATH_UPAPFILE;
addrs = opts = NULL;
ret = UPAP_AUTHNAK;
f = fopen(filename, "r");
if (f == NULL) {
error("Can't open PAP password file %s: %m", filename);
} else {
check_access(f, filename);
if (scan_authfile(f, user, our_name, secret, &addrs, &opts, filename, 0) < 0) {
warn("no PAP secret found for %s", user);
} else {
/*
* If the secret is "@login", it means to check
* the password against the login database.
*/
int login_secret = strcmp(secret, "@login") == 0;
ret = UPAP_AUTHACK;
if (uselogin || login_secret) {
/* login option or secret is @login */
if (session_full(user, passwd, devnam, msg) == 0) {
ret = UPAP_AUTHNAK;
}
} else if (session_mgmt) {
if (session_check(user, NULL, devnam, NULL) == 0) {
warn("Peer %q failed PAP Session verification", user);
ret = UPAP_AUTHNAK;
}
}
if (secret[0] != 0 && !login_secret) {
/* password given in pap-secrets - must match */
if (cryptpap || strcmp(passwd, secret) != 0) {
char *cbuf = crypt(passwd, secret);
if (!cbuf || strcmp(cbuf, secret) != 0)
ret = UPAP_AUTHNAK;
}
}
}
fclose(f);
}
if (ret == UPAP_AUTHNAK) {
if (**msg == 0)
*msg = "Login incorrect";
/*
* XXX can we ever get here more than once??
* 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) {
warn("%d LOGIN FAILURES ON %s, %s", attempts, devnam, user);
lcp_close(unit, "login failed");
}
if (attempts > 3)
sleep((u_int) (attempts - 3) * 5);
if (opts != NULL)
free_wordlist(opts);
} else {
attempts = 0; /* Reset count */
if (**msg == 0)
*msg = "Login ok";
set_allowed_addrs(unit, addrs, opts);
}
if (addrs != NULL)
free_wordlist(addrs);
BZERO(passwd, sizeof(passwd));
BZERO(secret, sizeof(secret));
return ret;
#endif
}
/*
* 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, *opts;
char secret[MAXWORDLEN];
/*
* Check if a plugin wants to handle this.
*/
ret = -1;
if (null_auth_hook)
ret = (*null_auth_hook)(&addrs, &opts);
/*
* Open the file of pap secrets and scan for a suitable secret.
*/
if (ret <= 0) {
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, &opts, filename, 0);
ret = i >= 0 && secret[0] == 0;
BZERO(secret, sizeof(secret));
fclose(f);
}
if (ret)
set_allowed_addrs(unit, addrs, opts);
else if (opts != 0)
free_wordlist(opts);
if (addrs != 0)
free_wordlist(addrs);
return ret;
}
/*
* 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.
* Assumes passwd points to MAXSECRETLEN bytes of space (if non-null).
*/
static int
get_pap_passwd(passwd)
char *passwd;
{
char *filename;
FILE *f;
int ret;
char secret[MAXWORDLEN];
/*
* Check whether a plugin wants to supply this.
*/
if (pap_passwd_hook) {
ret = (*pap_passwd_hook)(user, passwd);
if (ret >= 0)
return ret;
}
filename = _PATH_UPAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
check_access(f, filename);
ret = scan_authfile(f, user,
(remote_name[0]? remote_name: NULL),
secret, NULL, NULL, filename, 0);
fclose(f);
if (ret < 0)
return 0;
if (passwd != NULL)
strlcpy(passwd, secret, MAXSECRETLEN);
BZERO(secret, sizeof(secret));
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(lacks_ipp)
int *lacks_ipp;
{
FILE *f;
int ret;
char *filename;
struct wordlist *addrs;
/* let the plugin decide, if there is one */
if (pap_check_hook) {
ret = (*pap_check_hook)();
if (ret >= 0)
return ret;
}
filename = _PATH_UPAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
ret = scan_authfile(f, (explicit_remote? remote_name: NULL), our_name,
NULL, &addrs, NULL, filename, 0);
fclose(f);
if (ret >= 0 && !some_ip_ok(addrs)) {
if (lacks_ipp != 0)
*lacks_ipp = 1;
ret = -1;
}
if (addrs != 0)
free_wordlist(addrs);
return ret >= 0;
}
/*
* 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, need_ip, lacks_ipp)
char *client;
char *server;
int need_ip;
int *lacks_ipp;
{
FILE *f;
int ret;
char *filename;
struct wordlist *addrs;
if (chap_check_hook) {
ret = (*chap_check_hook)();
if (ret >= 0) {
return ret;
}
}
filename = _PATH_CHAPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
if (client != NULL && client[0] == 0)
client = NULL;
else if (server != NULL && server[0] == 0)
server = NULL;
ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
fclose(f);
if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
if (lacks_ipp != 0)
*lacks_ipp = 1;
ret = -1;
}
if (addrs != 0)
free_wordlist(addrs);
return ret >= 0;
}
/*
* have_srp_secret - check whether we have a SRP 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_srp_secret(client, server, need_ip, lacks_ipp)
char *client;
char *server;
int need_ip;
int *lacks_ipp;
{
FILE *f;
int ret;
char *filename;
struct wordlist *addrs;
filename = _PATH_SRPFILE;
f = fopen(filename, "r");
if (f == NULL)
return 0;
if (client != NULL && client[0] == 0)
client = NULL;
else if (server != NULL && server[0] == 0)
server = NULL;
ret = scan_authfile(f, client, server, NULL, &addrs, NULL, filename, 0);
fclose(f);
if (ret >= 0 && need_ip && !some_ip_ok(addrs)) {
if (lacks_ipp != 0)
*lacks_ipp = 1;
ret = -1;
}
if (addrs != 0)
free_wordlist(addrs);
return ret >= 0;
}
/*
* 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, am_server)
int unit;
char *client;
char *server;
char *secret;
int *secret_len;
int am_server;
{
FILE *f;
int ret, len;
char *filename;
struct wordlist *addrs, *opts;
char secbuf[MAXWORDLEN];
if (!am_server && passwd[0] != 0) {
strlcpy(secbuf, passwd, sizeof(secbuf));
} else if (!am_server && chap_passwd_hook) {
if ( (*chap_passwd_hook)(client, secbuf) < 0) {
error("Unable to obtain CHAP password for %s on %s from plugin",
client, server);
return 0;
}
} else {
filename = _PATH_CHAPFILE;
addrs = NULL;
secbuf[0] = 0;
f = fopen(filename, "r");
if (f == NULL) {
error("Can't open chap secret file %s: %m", filename);
return 0;
}
check_access(f, filename);
ret = scan_authfile(f, client, server, secbuf, &addrs, &opts, filename, 0);
fclose(f);
if (ret < 0)
return 0;
if (am_server)
set_allowed_addrs(unit, addrs, opts);
else if (opts != 0)
free_wordlist(opts);
if (addrs != 0)
free_wordlist(addrs);
}
len = strlen(secbuf);
if (len > MAXSECRETLEN) {
error("Secret for %s on %s is too long", client, server);
len = MAXSECRETLEN;
}
BCOPY(secbuf, secret, len);
BZERO(secbuf, sizeof(secbuf));
*secret_len = len;
return 1;
}
/*
* get_srp_secret - open the SRP secret file and return the secret
* for authenticating the given client on the given server.
* (We could be either client or server).
*/
int
get_srp_secret(unit, client, server, secret, am_server)
int unit;
char *client;
char *server;
char *secret;
int am_server;
{
FILE *fp;
int ret;
char *filename;
struct wordlist *addrs, *opts;
if (!am_server && passwd[0] != '\0') {
strlcpy(secret, passwd, MAXWORDLEN);
} else {
filename = _PATH_SRPFILE;
addrs = NULL;
fp = fopen(filename, "r");
if (fp == NULL) {
error("Can't open srp secret file %s: %m", filename);
return 0;
}
check_access(fp, filename);
secret[0] = '\0';
ret = scan_authfile(fp, client, server, secret, &addrs, &opts,
filename, am_server);
fclose(fp);
if (ret < 0)
return 0;
if (am_server)
set_allowed_addrs(unit, addrs, opts);
else if (opts != NULL)
free_wordlist(opts);
if (addrs != NULL)
free_wordlist(addrs);
}
return 1;
}
/*
* set_allowed_addrs() - set the list of allowed addresses.
* Also looks for `--' indicating options to apply for this peer
* and leaves the following words in extra_options.
*/
static void
set_allowed_addrs(unit, addrs, opts)
int unit;
struct wordlist *addrs;
struct wordlist *opts;
{
int n;
struct wordlist *ap, **plink;
struct permitted_ip *ip;
char *ptr_word, *ptr_mask;
struct hostent *hp;
struct netent *np;
u_int32_t a, mask, ah, offset;
struct ipcp_options *wo = &ipcp_wantoptions[unit];
u_int32_t suggested_ip = 0;
if (addresses[unit] != NULL)
free(addresses[unit]);
addresses[unit] = NULL;
if (extra_options != NULL)
free_wordlist(extra_options);
extra_options = opts;
/*
* Count the number of IP addresses given.
*/
n = wordlist_count(addrs) + wordlist_count(noauth_addrs);
if (n == 0)
return;
ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip));
if (ip == 0)
return;
/* temporarily append the noauth_addrs list to addrs */
for (plink = &addrs; *plink != NULL; plink = &(*plink)->next)
;
*plink = noauth_addrs;
n = 0;
for (ap = addrs; ap != NULL; ap = ap->next) {
/* "-" means no addresses authorized, "*" means any address allowed */
ptr_word = ap->word;
if (strcmp(ptr_word, "-") == 0)
break;
if (strcmp(ptr_word, "*") == 0) {
ip[n].permit = 1;
ip[n].base = ip[n].mask = 0;
++n;
break;
}
ip[n].permit = 1;
if (*ptr_word == '!') {
ip[n].permit = 0;
++ptr_word;
}
mask = ~ (u_int32_t) 0;
offset = 0;
ptr_mask = strchr (ptr_word, '/');
if (ptr_mask != NULL) {
int bit_count;
char *endp;
bit_count = (int) strtol (ptr_mask+1, &endp, 10);
if (bit_count <= 0 || bit_count > 32) {
warn("invalid address length %v in auth. address list",
ptr_mask+1);
continue;
}
bit_count = 32 - bit_count; /* # bits in host part */
if (*endp == '+') {
offset = ifunit + 1;
++endp;
}
if (*endp != 0) {
warn("invalid address length syntax: %v", ptr_mask+1);
continue;
}
*ptr_mask = '\0';
mask <<= bit_count;
}
hp = gethostbyname(ptr_word);
if (hp != NULL && hp->h_addrtype == AF_INET) {
a = *(u_int32_t *)hp->h_addr;
} else {
np = getnetbyname (ptr_word);
if (np != NULL && np->n_addrtype == AF_INET) {
a = htonl ((u_int32_t)np->n_net);
if (ptr_mask == NULL) {
/* calculate appropriate mask for net */
ah = ntohl(a);
if (IN_CLASSA(ah))
mask = IN_CLASSA_NET;
else if (IN_CLASSB(ah))
mask = IN_CLASSB_NET;
else if (IN_CLASSC(ah))
mask = IN_CLASSC_NET;
}
} else {
a = inet_addr (ptr_word);
}
}
if (ptr_mask != NULL)
*ptr_mask = '/';
if (a == (u_int32_t)-1L) {
warn("unknown host %s in auth. address list", ap->word);
continue;
}
if (offset != 0) {
if (offset >= ~mask) {
warn("interface unit %d too large for subnet %v",
ifunit, ptr_word);
continue;
}
a = htonl((ntohl(a) & mask) + offset);
mask = ~(u_int32_t)0;
}
ip[n].mask = htonl(mask);
ip[n].base = a & ip[n].mask;
++n;
if (~mask == 0 && suggested_ip == 0)
suggested_ip = a;
}
*plink = NULL;
ip[n].permit = 0; /* make the last entry forbid all addresses */
ip[n].base = 0; /* to terminate the list */
ip[n].mask = 0;
addresses[unit] = ip;
/*
* If the address given for the peer isn't authorized, or if
* the user hasn't given one, AND there is an authorized address
* which is a single host, then use that if we find one.
*/
if (suggested_ip != 0
&& (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) {
wo->hisaddr = suggested_ip;
/*
* Do we insist on this address? No, if there are other
* addresses authorized than the suggested one.
*/
if (n > 1)
wo->accept_remote = 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_int32_t addr;
{
int ok;
/* don't allow loopback or multicast address */
if (bad_ip_adrs(addr))
return 0;
if (allowed_address_hook) {
ok = allowed_address_hook(addr);
if (ok >= 0) return ok;
}
if (addresses[unit] != NULL) {
ok = ip_addr_check(addr, addresses[unit]);
if (ok >= 0)
return ok;
}
if (auth_required)
return 0; /* no addresses authorized */
return allow_any_ip || privileged || !have_route_to(addr);
}
static int
ip_addr_check(addr, addrs)
u_int32_t addr;
struct permitted_ip *addrs;
{
for (; ; ++addrs)
if ((addr & addrs->mask) == addrs->base)
return addrs->permit;
}
/*
* 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);
}
/*
* some_ip_ok - check a wordlist to see if it authorizes any
* IP address(es).
*/
static int
some_ip_ok(addrs)
struct wordlist *addrs;
{
for (; addrs != 0; addrs = addrs->next) {
if (addrs->word[0] == '-')
break;
if (addrs->word[0] != '!')
return 1; /* some IP address is allowed */
}
return 0;
}
/*
* auth_number - check whether the remote number is allowed to connect.
* Returns 1 if authorized, 0 otherwise.
*/
int
auth_number()
{
struct wordlist *wp = permitted_numbers;
int l;
/* Allow all if no authorization list. */
if (!wp)
return 1;
/* Allow if we have a match in the authorization list. */
while (wp) {
/* trailing '*' wildcard */
l = strlen(wp->word);
if ((wp->word)[l - 1] == '*')
l--;
if (!strncasecmp(wp->word, remote_number, l))
return 1;
wp = wp->next;
}
return 0;
}
/*
* check_access - complain if a secret file has too-liberal permissions.
*/
static void
check_access(f, filename)
FILE *f;
char *filename;
{
struct stat sbuf;
if (fstat(fileno(f), &sbuf) < 0) {
warn("cannot stat secret file %s: %m", filename);
} else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {
warn("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 up to a "--" (i.e. address authorization
* info) are placed in a wordlist and returned in *addrs. Any
* following words (extra options) are placed in a wordlist and
* returned in *opts.
* We assume secret is NULL or points to MAXWORDLEN bytes of space.
* Flags are non-zero if we need two colons in the secret in order to
* match.
*/
static int
scan_authfile(f, client, server, secret, addrs, opts, filename, flags)
FILE *f;
char *client;
char *server;
char *secret;
struct wordlist **addrs;
struct wordlist **opts;
char *filename;
int flags;
{
int newline, xxx;
int got_flag, best_flag;
FILE *sf;
struct wordlist *ap, *addr_list, *alist, **app;
char word[MAXWORDLEN];
char atfile[MAXWORDLEN];
char lsecret[MAXWORDLEN];
char *cp;
if (addrs != NULL)
*addrs = NULL;
if (opts != NULL)
*opts = 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 (!ISWILD(word)) {
if (server != NULL && strcmp(word, server) != 0)
continue;
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;
/*
* SRP-SHA1 authenticator should never be reading secrets from
* a file. (Authenticatee may, though.)
*/
if (flags && ((cp = strchr(word, ':')) == NULL ||
strchr(cp + 1, ':') == NULL))
continue;
if (secret != NULL) {
/*
* Special syntax: @/pathname means read secret from file.
*/
if (word[0] == '@' && word[1] == '/') {
strlcpy(atfile, word+1, sizeof(atfile));
if ((sf = fopen(atfile, "r")) == NULL) {
warn("can't open indirect secret file %s", atfile);
continue;
}
check_access(sf, atfile);
if (!getword(sf, word, &xxx, atfile)) {
warn("no secret in indirect secret file %s", atfile);
fclose(sf);
continue;
}
fclose(sf);
}
strlcpy(lsecret, word, sizeof(lsecret));
}
/*
* Now read address authorization info and make a wordlist.
*/
app = &alist;
for (;;) {
if (!getword(f, word, &newline, filename) || newline)
break;
ap = (struct wordlist *)
malloc(sizeof(struct wordlist) + strlen(word) + 1);
if (ap == NULL)
novm("authorized addresses");
ap->word = (char *) (ap + 1);
strcpy(ap->word, word);
*app = ap;
app = &ap->next;
}
*app = NULL;
/*
* This is the best so far; remember it.
*/
best_flag = got_flag;
if (addr_list)
free_wordlist(addr_list);
addr_list = alist;
if (secret != NULL)
strlcpy(secret, lsecret, MAXWORDLEN);
if (!newline)
break;
}
/* scan for a -- word indicating the start of options */
for (app = &addr_list; (ap = *app) != NULL; app = &ap->next)
if (strcmp(ap->word, "--") == 0)
break;
/* ap = start of options */
if (ap != NULL) {
ap = ap->next; /* first option */
free(*app); /* free the "--" word */
*app = NULL; /* terminate addr list */
}
if (opts != NULL)
*opts = ap;
else if (ap != NULL)
free_wordlist(ap);
if (addrs != NULL)
*addrs = addr_list;
else if (addr_list != NULL)
free_wordlist(addr_list);
return best_flag;
}
/*
* wordlist_count - return the number of items in a wordlist
*/
static int
wordlist_count(wp)
struct wordlist *wp;
{
int n;
for (n = 0; wp != NULL; wp = wp->next)
++n;
return n;
}
/*
* 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_done - called when the auth-up or auth-down script
* has finished.
*/
static void
auth_script_done(arg)
void *arg;
{
auth_script_pid = 0;
switch (auth_script_state) {
case s_up:
if (auth_state == s_down) {
auth_script_state = s_down;
auth_script(_PATH_AUTHDOWN);
}
break;
case s_down:
if (auth_state == s_up) {
auth_script_state = s_up;
auth_script(_PATH_AUTHUP);
}
break;
}
}
/*
* auth_script - execute a script with arguments
* interface-name peer-name real-user tty speed
*/
static void
auth_script(script)
char *script;
{
char strspeed[32];
struct passwd *pw;
char struid[32];
char *user_name;
char *argv[8];
if ((pw = getpwuid(getuid())) != NULL && pw->pw_name != NULL)
user_name = pw->pw_name;
else {
slprintf(struid, sizeof(struid), "%d", getuid());
user_name = struid;
}
slprintf(strspeed, sizeof(strspeed), "%d", baud_rate);
argv[0] = script;
argv[1] = ifname;
argv[2] = peer_authname;
argv[3] = user_name;
argv[4] = devnam;
argv[5] = strspeed;
argv[6] = NULL;
auth_script_pid = run_program(script, argv, 0, auth_script_done, NULL, 0);
}