isdn4k-utils/ipppd/upap.c

668 lines
15 KiB
C

/*
* upap.c - User/Password Authentication Protocol.
*
* 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.
*/
char upap_rcsid[] = "$Id: upap.c,v 1.7 2004/02/12 11:27:39 keil Exp $";
/*
* TODO:
*/
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include <syslog.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "fsm.h"
#include "ipppd.h"
#include "ipcp.h"
#include "upap.h"
#include "pathnames.h"
extern int log_raw_password;
/*
* Protocol entry points.
*/
static void upap_init __P((int));
static void upap_lowerup __P((int));
static void upap_lowerdown __P((int));
static void upap_input __P((int, u_char *, int));
static void upap_protrej __P((int));
static int upap_printpkt __P((u_char *, int,
void (*) __P((void *, char *, ...)), void *));
struct protent pap_protent = {
PPP_PAP,
upap_init,
upap_input,
upap_protrej,
upap_lowerup,
upap_lowerdown,
NULL,
NULL,
upap_printpkt,
NULL,
1,
"PAP",
NULL,
NULL,
NULL
};
upap_state upap[NUM_PPP]; /* UPAP state; one for each unit */
static void upap_timeout __P((caddr_t));
static void upap_reqtimeout __P((caddr_t));
static void upap_rauthreq __P((upap_state *, u_char *, int, int));
static void upap_rauthack __P((upap_state *, u_char *, int, int));
static void upap_rauthnak __P((upap_state *, u_char *, int, int));
static void upap_sauthreq __P((upap_state *));
static void upap_sresp __P((upap_state *, int, int, char *, int));
void set_userip(char *ruser,int ruserlen)
{
char line[1024];
char name[64];
FILE *fd;
int base;
int ofs;
char *lname;
char *lip;
ipcp_options *wo = &ipcp_wantoptions[0];
if (ruserlen) {
memcpy(name,ruser, ruserlen);
name[ruserlen]='\0';
}
else
strncpy(name, ruser, sizeof(name)-1);
fd = fopen(_PATH_USERIPTAB, "r");
if (fd) {
while (fgets(line, sizeof(line)-1, fd)) {
base = strspn(line, " \t\n\r");
if (line[base] == '#')
continue;
lname = &(line[base]);
ofs = strcspn(lname, " \n\t\r\n");
lname[ofs] = '\0';
lip = &(lname[ofs+1]);
base = strspn(lip, " \t\n\r");
lip = &(lip[base]);
ofs = strcspn(lip, " \n\t\r\n");
lip[ofs] = '\0';
if (!strcmp(name, lname)) {
struct in_addr ip;
if (inet_aton(lip, &ip)) {
wo->hisaddr = ip.s_addr;
UPAPDEBUG((LOG_INFO, "set_userip: found users(%s) ip(%s).",lname, lip));
}
break;
}
}
fclose(fd);
}
}
/*
* upap_init - Initialize a UPAP unit.
*/
void upap_init(int unit)
{
upap_state *u = &upap[unit];
u->us_unit = unit;
u->us_ruser[0] = 0;
u->us_ruserlen = 0;
u->us_rpasswd[0] = 0;
u->us_rpasswdlen = 0;
u->us_user = NULL;
u->us_userlen = 0;
u->us_passwd = NULL;
u->us_passwdlen = 0;
u->us_clientstate = UPAPCS_INITIAL;
u->us_serverstate = UPAPSS_INITIAL;
u->us_id = 0;
u->us_timeouttime = UPAP_DEFTIMEOUT;
u->us_maxtransmits = 10;
u->us_reqtimeout = UPAP_DEFREQTIME;
}
/*
* upap_authwithpeer - Authenticate us with our peer (start client).
*
* Set new state and send authenticate's.
*/
void upap_authwithpeer(int unit,char *user,char *password)
{
upap_state *u = &upap[unit];
/* Save the username and password we're given */
u->us_user = user;
u->us_userlen = strlen(user);
u->us_passwd = password;
u->us_passwdlen = strlen(password);
u->us_transmits = 0;
/* Lower layer up yet? */
if (u->us_clientstate == UPAPCS_INITIAL ||
u->us_clientstate == UPAPCS_PENDING) {
u->us_clientstate = UPAPCS_PENDING;
return;
}
upap_sauthreq(u); /* Start protocol */
}
/*
* upap_authpeer - Authenticate our peer (start server).
*
* Set new state.
*/
void upap_authpeer(int unit)
{
upap_state *u = &upap[unit];
/* Lower layer up yet? */
if (u->us_serverstate == UPAPSS_INITIAL ||
u->us_serverstate == UPAPSS_PENDING) {
u->us_serverstate = UPAPSS_PENDING;
return;
}
u->us_serverstate = UPAPSS_LISTEN;
if (u->us_reqtimeout > 0)
TIMEOUT(upap_reqtimeout, (caddr_t) u, u->us_reqtimeout);
}
/*
* upap_timeout - Retransmission timer for sending auth-reqs expired.
*/
static void upap_timeout(caddr_t arg)
{
upap_state *u = (upap_state *) arg;
if (u->us_clientstate != UPAPCS_AUTHREQ)
return;
if (u->us_transmits >= u->us_maxtransmits) {
/* give up in disgust */
syslog(LOG_ERR, "No response to PAP authenticate-requests");
u->us_clientstate = UPAPCS_BADAUTH;
auth_withpeer_fail(u->us_unit, PPP_PAP, AUTH_ERR_TIME | AUTH_ERR_PAP);
return;
}
upap_sauthreq(u); /* Send Authenticate-Request */
}
/*
* upap_reqtimeout - Give up waiting for the peer to send an auth-req.
*/
static void
upap_reqtimeout(arg)
caddr_t arg;
{
upap_state *u = (upap_state *) arg;
if (u->us_serverstate != UPAPSS_LISTEN)
return; /* huh?? */
auth_peer_fail(u->us_unit, PPP_PAP, AUTH_ERR_TIME | AUTH_ERR_PAP);
u->us_serverstate = UPAPSS_BADAUTH;
}
/*
* upap_lowerup - The lower layer is up.
*
* Start authenticating if pending.
*/
void upap_lowerup(int unit)
{
upap_state *u = &upap[unit];
if (u->us_clientstate == UPAPCS_INITIAL)
u->us_clientstate = UPAPCS_CLOSED;
else if (u->us_clientstate == UPAPCS_PENDING) {
upap_sauthreq(u); /* send an auth-request */
}
if (u->us_serverstate == UPAPSS_INITIAL)
u->us_serverstate = UPAPSS_CLOSED;
else if (u->us_serverstate == UPAPSS_PENDING) {
u->us_serverstate = UPAPSS_LISTEN;
if (u->us_reqtimeout > 0)
TIMEOUT(upap_reqtimeout, (caddr_t) u, u->us_reqtimeout);
}
}
/*
* upap_lowerdown - The lower layer is down.
*
* Cancel all timeouts.
*/
void upap_lowerdown(int unit)
{
upap_state *u = &upap[unit];
if (u->us_clientstate == UPAPCS_AUTHREQ) /* Timeout pending? */
UNTIMEOUT(upap_timeout, (caddr_t) u); /* Cancel timeout */
if (u->us_serverstate == UPAPSS_LISTEN && u->us_reqtimeout > 0)
UNTIMEOUT(upap_reqtimeout, (caddr_t) u);
u->us_clientstate = UPAPCS_INITIAL;
u->us_serverstate = UPAPSS_INITIAL;
}
/*
* upap_protrej - Peer doesn't speak this protocol.
*
* This shouldn't happen. In any case, pretend lower layer went down.
*/
void upap_protrej(int linkunit)
{
int unit = lns[linkunit].upap_unit;
upap_state *u = &upap[unit]; /* link unit! */
if (u->us_clientstate == UPAPCS_AUTHREQ) {
syslog(LOG_ERR, "PAP authentication failed due to protocol-reject");
auth_withpeer_fail(u->us_unit, PPP_PAP, AUTH_ERR_PROT | AUTH_ERR_PAP);
}
if (u->us_serverstate == UPAPSS_LISTEN) {
syslog(LOG_ERR, "PAP authentication of peer failed (protocol-reject)");
auth_peer_fail(u->us_unit, PPP_PAP, AUTH_ERR_PROT | AUTH_ERR_PAP);
}
upap_lowerdown(unit);
}
/*
* upap_input - Input UPAP packet.
*/
void upap_input(int linkunit,u_char *inpacket,int l)
{
int unit = lns[linkunit].upap_unit;
upap_state *u = &upap[unit];
u_char *inp;
u_char code, id;
int len;
/*
* Parse header (code, id and length).
* If packet too short, drop it.
*/
inp = inpacket;
if (l < UPAP_HEADERLEN) {
UPAPDEBUG((LOG_INFO, "upap_input: rcvd short header."));
return;
}
GETCHAR(code, inp);
GETCHAR(id, inp);
GETSHORT(len, inp);
if (len < UPAP_HEADERLEN) {
UPAPDEBUG((LOG_INFO, "upap_input: rcvd illegal length."));
return;
}
if (len > l) {
UPAPDEBUG((LOG_INFO, "upap_input: rcvd short packet."));
return;
}
len -= UPAP_HEADERLEN;
/*
* Action depends on code.
*/
switch (code) {
case UPAP_AUTHREQ:
upap_rauthreq(u, inp, id, len);
break;
case UPAP_AUTHACK:
upap_rauthack(u, inp, id, len);
break;
case UPAP_AUTHNAK:
upap_rauthnak(u, inp, id, len);
break;
default: /* XXX Need code reject */
break;
}
}
/*
* upap_rauth - Receive Authenticate.
*/
static void upap_rauthreq(upap_state *u,u_char *inp,int id,int len)
{
u_char ruserlen, rpasswdlen;
char *ruser, *rpasswd;
int retcode;
char *msg;
int msglen;
UPAPDEBUG((LOG_INFO, "upap_rauth: Rcvd id %d.", id));
if (u->us_serverstate < UPAPSS_LISTEN)
return;
/*
* If we receive a duplicate authenticate-request, we are
* supposed to return the same status as for the first request.
*/
if (u->us_serverstate == UPAPSS_OPEN) {
upap_sresp(u, UPAP_AUTHACK, id, "", 0); /* return auth-ack */
return;
}
if (u->us_serverstate == UPAPSS_BADAUTH) {
upap_sresp(u, UPAP_AUTHNAK, id, "", 0); /* return auth-nak */
return;
}
/*
* Parse user/passwd.
*/
if (len < sizeof (u_char)) {
UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
return;
}
GETCHAR(ruserlen, inp);
len -= sizeof (u_char) + ruserlen + sizeof (u_char);
if (len < 0) {
UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
return;
}
ruser = (char *) inp;
INCPTR(ruserlen, inp);
GETCHAR(rpasswdlen, inp);
if (len < rpasswdlen) {
UPAPDEBUG((LOG_INFO, "upap_rauth: rcvd short packet."));
return;
}
rpasswd = (char *) inp;
/*
* Check the username and password given.
*/
if(ruserlen > 64)
ruserlen = 64;
if(rpasswdlen > 64)
rpasswdlen = 64;
strncpy(u->us_ruser,ruser,(int)ruserlen);
strncpy(u->us_rpasswd,rpasswd,(int)rpasswdlen);
u->us_rpasswdlen = rpasswdlen;
u->us_ruserlen = ruserlen;
#ifdef RADIUS
retcode = radius_check_passwd(u->us_unit, ruser, ruserlen, rpasswd,
rpasswdlen, &msg, &msglen);
#else
retcode = check_passwd(u->us_unit, ruser, ruserlen, rpasswd,
rpasswdlen, &msg, &msglen);
#endif
upap_sresp(u, retcode, id, msg, msglen);
if (retcode == UPAP_AUTHACK) {
set_userip(ruser, ruserlen);
u->us_serverstate = UPAPSS_OPEN;
auth_peer_success(u->us_unit, PPP_PAP);
} else {
u->us_serverstate = UPAPSS_BADAUTH;
auth_peer_fail(u->us_unit, PPP_PAP, AUTH_ERR_USER | AUTH_ERR_PAP);
}
if (u->us_reqtimeout > 0)
UNTIMEOUT(upap_reqtimeout, (caddr_t) u);
}
/*
* upap_rauthack - Receive Authenticate-Ack.
*/
static void
upap_rauthack(u, inp, id, len)
upap_state *u;
u_char *inp;
int id;
int len;
{
u_char msglen;
char *msg;
UPAPDEBUG((LOG_INFO, "upap_rauthack: Rcvd id %d.", id));
if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
return;
/*
* Parse message.
*/
if (len < sizeof (u_char)) {
UPAPDEBUG((LOG_INFO, "upap_rauthack: rcvd short packet."));
return;
}
GETCHAR(msglen, inp);
len -= sizeof (u_char);
if (len < msglen) {
UPAPDEBUG((LOG_INFO, "upap_rauthack: rcvd short packet."));
return;
}
msg = (char *) inp;
PRINTMSG(msg, msglen);
u->us_clientstate = UPAPCS_OPEN;
auth_withpeer_success(u->us_unit, PPP_PAP);
}
/*
* upap_rauthnak - Receive Authenticate-Nakk.
*/
static void
upap_rauthnak(u, inp, id, len)
upap_state *u;
u_char *inp;
int id;
int len;
{
u_char msglen;
char *msg;
UPAPDEBUG((LOG_INFO, "upap_rauthnak: Rcvd id %d.", id));
if (u->us_clientstate != UPAPCS_AUTHREQ) /* XXX */
return;
/*
* Parse message.
*/
if (len < sizeof (u_char)) {
UPAPDEBUG((LOG_INFO, "upap_rauthnak: rcvd short packet."));
return;
}
GETCHAR(msglen, inp);
len -= sizeof (u_char);
if (len < msglen) {
UPAPDEBUG((LOG_INFO, "upap_rauthnak: rcvd short packet."));
return;
}
msg = (char *) inp;
PRINTMSG(msg, msglen);
u->us_clientstate = UPAPCS_BADAUTH;
syslog(LOG_ERR, "PAP authentication failed");
auth_withpeer_fail(u->us_unit, PPP_PAP, AUTH_ERR_USER | AUTH_ERR_PAP);
}
/*
* upap_sauthreq - Send an Authenticate-Request.
*/
static void
upap_sauthreq(u)
upap_state *u;
{
u_char *outp;
int outlen;
outlen = UPAP_HEADERLEN + 2 * sizeof (u_char) +
u->us_userlen + u->us_passwdlen;
outp = outpacket_buf;
MAKEHEADER(outp, PPP_PAP);
PUTCHAR(UPAP_AUTHREQ, outp);
PUTCHAR(++u->us_id, outp);
PUTSHORT(outlen, outp);
PUTCHAR(u->us_userlen, outp);
BCOPY(u->us_user, outp, u->us_userlen);
INCPTR(u->us_userlen, outp);
PUTCHAR(u->us_passwdlen, outp);
BCOPY(u->us_passwd, outp, u->us_passwdlen);
output_ppp(u->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
UPAPDEBUG((LOG_INFO, "upap_sauth: Sent id %d.", u->us_id));
TIMEOUT(upap_timeout, (caddr_t) u, u->us_timeouttime);
++u->us_transmits;
u->us_clientstate = UPAPCS_AUTHREQ;
}
/*
* upap_sresp - Send a response (ack or nak).
*/
static void
upap_sresp(u, code, id, msg, msglen)
upap_state *u;
u_char code, id;
char *msg;
int msglen;
{
u_char *outp;
int outlen;
outlen = UPAP_HEADERLEN + sizeof (u_char) + msglen;
outp = outpacket_buf;
MAKEHEADER(outp, PPP_PAP);
PUTCHAR(code, outp);
PUTCHAR(id, outp);
PUTSHORT(outlen, outp);
PUTCHAR(msglen, outp);
BCOPY(msg, outp, msglen);
output_ppp(u->us_unit, outpacket_buf, outlen + PPP_HDRLEN);
UPAPDEBUG((LOG_INFO, "upap_sresp: Sent code %d, id %d.", code, id));
}
/*
* upap_printpkt - print the contents of a PAP packet.
*/
char *upap_codenames[] = {
"AuthReq", "AuthAck", "AuthNak"
};
int
upap_printpkt(p, plen, printer, arg)
u_char *p;
int plen;
void (*printer) __P((void *, char *, ...));
void *arg;
{
int code, id, len;
int mlen, ulen, wlen;
char *user, *pwd, *msg;
u_char *pstart;
if (plen < UPAP_HEADERLEN)
return 0;
pstart = p;
GETCHAR(code, p);
GETCHAR(id, p);
GETSHORT(len, p);
if (len < UPAP_HEADERLEN || len > plen)
return 0;
if (code >= 1 && code <= sizeof(upap_codenames) / sizeof(char *))
printer(arg, " %s", upap_codenames[code-1]);
else
printer(arg, " code=0x%x", code);
printer(arg, " id=0x%x", id);
len -= UPAP_HEADERLEN;
switch (code) {
case UPAP_AUTHREQ:
if (len < 1)
break;
ulen = p[0];
if (len < ulen + 2)
break;
wlen = p[ulen + 1];
if (len < ulen + wlen + 2)
break;
user = (char *) (p + 1);
pwd = (char *) (p + ulen + 2);
p += ulen + wlen + 2;
len -= ulen + wlen + 2;
printer(arg, " user=");
print_string(user, ulen, printer, arg);
if(log_raw_password) {
printer(arg, " password=");
print_string(pwd, wlen, printer, arg);
}
else
printer(arg, " password not logged for security reasons! Use '+pwlog' option to enable full logging.");
break;
case UPAP_AUTHACK:
case UPAP_AUTHNAK:
if (len < 1)
break;
mlen = p[0];
if (len < mlen + 1)
break;
msg = (char *) (p + 1);
p += mlen + 1;
len -= mlen + 1;
printer(arg, "msg=");
print_string(msg, mlen, printer, arg);
break;
}
/* print the rest of the bytes in the packet */
for (; len > 0; --len) {
GETCHAR(code, p);
printer(arg, " %.2x", code);
}
return p - pstart;
}