NetBSD-5.0.2/lib/libtelnet/auth.c
/* $NetBSD: auth.c,v 1.19 2006/03/20 04:03:22 christos Exp $ */
/*-
* Copyright (c) 1991, 1993
* The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)auth.c 8.3 (Berkeley) 5/30/95"
#else
__RCSID("$NetBSD: auth.c,v 1.19 2006/03/20 04:03:22 christos Exp $");
#endif
#endif /* not lint */
/*
* Copyright (C) 1990 by the Massachusetts Institute of Technology
*
* Export of this software from the United States of America is assumed
* to require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
#ifdef AUTHENTICATION
#include <stdio.h>
#include <sys/types.h>
#include <signal.h>
#define AUTH_NAMES
#include <arpa/telnet.h>
#include <stdlib.h>
#include <unistd.h>
#ifdef NO_STRING_H
#include <strings.h>
#else
#include <string.h>
#endif
#include "encrypt.h"
#include "auth.h"
#include "misc-proto.h"
#include "auth-proto.h"
#define typemask(x) (1<<((x)-1))
#ifdef RSA_ENCPWD
extern rsaencpwd_init();
extern rsaencpwd_send();
extern rsaencpwd_is();
extern rsaencpwd_reply();
extern rsaencpwd_status();
extern rsaencpwd_printsub();
#endif
int auth_debug_mode = 0;
static const char *Name = "Noname";
static int Server = 0;
static Authenticator *authenticated = 0;
static int authenticating = 0;
static int validuser = 0;
static unsigned char _auth_send_data[256];
static unsigned char *auth_send_data;
static int auth_send_cnt = 0;
static void auth_intr(int);
/*
* Authentication types supported. Plese note that these are stored
* in priority order, i.e. try the first one first.
*/
Authenticator authenticators[] = {
#ifdef SPX
{ AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
spx_init,
spx_send,
spx_is,
spx_reply,
spx_status,
spx_printsub },
{ AUTHTYPE_SPX, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
spx_init,
spx_send,
spx_is,
spx_reply,
spx_status,
spx_printsub },
#endif
#ifdef KRB5
# ifdef ENCRYPTION
{ AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_MUTUAL,
kerberos5_init,
kerberos5_send,
kerberos5_is,
kerberos5_reply,
kerberos5_status,
kerberos5_printsub },
# endif /* ENCRYPTION */
{ AUTHTYPE_KERBEROS_V5, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
kerberos5_init,
kerberos5_send,
kerberos5_is,
kerberos5_reply,
kerberos5_status,
kerberos5_printsub },
#endif
#ifdef RSA_ENCPWD
{ AUTHTYPE_RSA_ENCPWD, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
rsaencpwd_init,
rsaencpwd_send,
rsaencpwd_is,
rsaencpwd_reply,
rsaencpwd_status,
rsaencpwd_printsub },
#endif
#ifdef SRA
{ AUTHTYPE_SRA, AUTH_WHO_CLIENT|AUTH_HOW_ONE_WAY,
sra_init,
sra_send,
sra_is,
sra_reply,
sra_status,
sra_printsub },
#endif
{ 0, 0, 0, 0, 0, 0, 0, 0 },
};
static Authenticator NoAuth = { 0 };
static int i_support = 0;
static int i_wont_support = 0;
Authenticator *
findauthenticator(type, way)
int type;
int way;
{
Authenticator *ap = authenticators;
while (ap->type && (ap->type != type || ap->way != way))
++ap;
return(ap->type ? ap : 0);
}
void
auth_init(name, server)
const char *name;
int server;
{
Authenticator *ap = authenticators;
Server = server;
Name = name;
i_support = 0;
authenticated = 0;
authenticating = 0;
while (ap->type) {
if (!ap->init || (*ap->init)(ap, server)) {
i_support |= typemask(ap->type);
if (auth_debug_mode)
printf(">>>%s: I support auth type %d %d\r\n",
Name,
ap->type, ap->way);
}
else if (auth_debug_mode)
printf(">>>%s: Init failed: auth type %d %d\r\n",
Name, ap->type, ap->way);
++ap;
}
}
void
auth_disable_name(name)
char *name;
{
int x;
for (x = 0; x < AUTHTYPE_CNT; ++x) {
if (AUTHTYPE_NAME(x) && !strcasecmp(name, AUTHTYPE_NAME(x))) {
i_wont_support |= typemask(x);
break;
}
}
}
int
getauthmask(type, maskp)
char *type;
int *maskp;
{
register int x;
if (AUTHTYPE_NAME(0) && !strcasecmp(type, AUTHTYPE_NAME(0))) {
*maskp = -1;
return(1);
}
for (x = 1; x < AUTHTYPE_CNT; ++x) {
if (AUTHTYPE_NAME(x) && !strcasecmp(type, AUTHTYPE_NAME(x))) {
*maskp = typemask(x);
return(1);
}
}
return(0);
}
int
auth_enable(type)
char *type;
{
return(auth_onoff(type, 1));
}
int
auth_disable(type)
char *type;
{
return(auth_onoff(type, 0));
}
int
auth_onoff(type, on)
char *type;
int on;
{
int i, mask = -1;
Authenticator *ap;
if (!strcasecmp(type, "?") || !strcasecmp(type, "help")) {
printf("auth %s 'type'\n", on ? "enable" : "disable");
printf("Where 'type' is one of:\n");
printf("\t%s\n", AUTHTYPE_NAME(0));
mask = 0;
for (ap = authenticators; ap->type; ap++) {
if ((mask & (i = typemask(ap->type))) != 0)
continue;
mask |= i;
printf("\t%s\n", AUTHTYPE_NAME(ap->type));
}
return(0);
}
if (!getauthmask(type, &mask)) {
printf("%s: invalid authentication type\n", type);
return(0);
}
if (on)
i_wont_support &= ~mask;
else
i_wont_support |= mask;
return(1);
}
int
auth_togdebug(on)
int on;
{
if (on < 0)
auth_debug_mode ^= 1;
else
auth_debug_mode = on;
printf("auth debugging %s\n", auth_debug_mode ? "enabled" : "disabled");
return(1);
}
int
auth_status(s)
char *s;
{
Authenticator *ap;
int i, mask;
if (i_wont_support == -1)
printf("Authentication disabled\n");
else
printf("Authentication enabled\n");
mask = 0;
for (ap = authenticators; ap->type; ap++) {
if ((mask & (i = typemask(ap->type))) != 0)
continue;
mask |= i;
printf("%s: %s\n", AUTHTYPE_NAME(ap->type),
(i_wont_support & typemask(ap->type)) ?
"disabled" : "enabled");
}
return(1);
}
/*
* This routine is called by the server to start authentication
* negotiation.
*/
void
auth_request()
{
static unsigned char str_request[64] = { IAC, SB,
TELOPT_AUTHENTICATION,
TELQUAL_SEND, };
Authenticator *ap = authenticators;
unsigned char *e = str_request + 4;
if (!authenticating) {
authenticating = 1;
while (ap->type) {
if (i_support & ~i_wont_support & typemask(ap->type)) {
if (auth_debug_mode) {
printf(">>>%s: Sending type %d %d\r\n",
Name, ap->type, ap->way);
}
*e++ = ap->type;
*e++ = ap->way;
}
++ap;
}
*e++ = IAC;
*e++ = SE;
telnet_net_write(str_request, e - str_request);
printsub('>', &str_request[2], e - str_request - 2);
}
}
/*
* This is called when an AUTH SEND is received.
* It should never arrive on the server side (as only the server can
* send an AUTH SEND).
* You should probably respond to it if you can...
*
* If you want to respond to the types out of order (i.e. even
* if he sends LOGIN KERBEROS and you support both, you respond
* with KERBEROS instead of LOGIN (which is against what the
* protocol says)) you will have to hack this code...
*/
void
auth_send(data, cnt)
unsigned char *data;
int cnt;
{
Authenticator *ap;
static unsigned char str_none[] = { IAC, SB, TELOPT_AUTHENTICATION,
TELQUAL_IS, AUTHTYPE_NULL, 0,
IAC, SE };
if (Server) {
if (auth_debug_mode) {
printf(">>>%s: auth_send called!\r\n", Name);
}
return;
}
if (auth_debug_mode) {
printf(">>>%s: auth_send got:", Name);
printd(data, cnt); printf("\r\n");
}
/*
* Save the data, if it is new, so that we can continue looking
* at it if the authorization we try doesn't work
*/
if (data < _auth_send_data ||
data > _auth_send_data + sizeof(_auth_send_data)) {
auth_send_cnt = cnt > sizeof(_auth_send_data)
? sizeof(_auth_send_data)
: cnt;
memmove((void *)_auth_send_data, (void *)data, auth_send_cnt);
auth_send_data = _auth_send_data;
} else {
/*
* This is probably a no-op, but we just make sure
*/
auth_send_data = data;
auth_send_cnt = cnt;
}
while ((auth_send_cnt -= 2) >= 0) {
if (auth_debug_mode)
printf(">>>%s: He supports %d\r\n",
Name, *auth_send_data);
if ((i_support & ~i_wont_support) & typemask(*auth_send_data)) {
ap = findauthenticator(auth_send_data[0],
auth_send_data[1]);
if (ap && ap->send) {
if (auth_debug_mode)
printf(">>>%s: Trying %d %d\r\n",
Name, auth_send_data[0],
auth_send_data[1]);
if ((*ap->send)(ap)) {
/*
* Okay, we found one we like
* and did it.
* we can go home now.
*/
if (auth_debug_mode)
printf(">>>%s: Using type %d\r\n",
Name, *auth_send_data);
auth_send_data += 2;
return;
}
}
/* else
* just continue on and look for the
* next one if we didn't do anything.
*/
}
auth_send_data += 2;
}
telnet_net_write(str_none, sizeof(str_none));
printsub('>', &str_none[2], sizeof(str_none) - 2);
if (auth_debug_mode)
printf(">>>%s: Sent failure message\r\n", Name);
auth_finished(0, AUTH_REJECT);
#ifdef KANNAN
/*
* We requested strong authentication, however no mechanisms worked.
* Therefore, exit on client end.
*/
printf("Unable to securely authenticate user ... exit\n");
exit(0);
#endif /* KANNAN */
}
void
auth_send_retry()
{
/*
* if auth_send_cnt <= 0 then auth_send will end up rejecting
* the authentication and informing the other side of this.
*/
auth_send(auth_send_data, auth_send_cnt);
}
void
auth_is(data, cnt)
unsigned char *data;
int cnt;
{
Authenticator *ap;
if (cnt < 2)
return;
if (data[0] == AUTHTYPE_NULL) {
auth_finished(0, AUTH_REJECT);
return;
}
if ((ap = findauthenticator(data[0], data[1])) != NULL) {
if (ap->is)
(*ap->is)(ap, data+2, cnt-2);
} else if (auth_debug_mode)
printf(">>>%s: Invalid authentication in IS: %d\r\n",
Name, *data);
}
void
auth_reply(data, cnt)
unsigned char *data;
int cnt;
{
Authenticator *ap;
if (cnt < 2)
return;
if ((ap = findauthenticator(data[0], data[1])) != NULL) {
if (ap->reply)
(*ap->reply)(ap, data+2, cnt-2);
} else if (auth_debug_mode)
printf(">>>%s: Invalid authentication in SEND: %d\r\n",
Name, *data);
}
void
auth_name(data, cnt)
unsigned char *data;
int cnt;
{
unsigned char savename[256];
if (cnt < 1) {
if (auth_debug_mode)
printf(">>>%s: Empty name in NAME\r\n", Name);
return;
}
if (cnt > sizeof(savename) - 1) {
if (auth_debug_mode)
printf(">>>%s: Name in NAME (%d) exceeds %ld length\r\n",
Name, cnt, (long)sizeof(savename)-1);
return;
}
memmove((void *)savename, (void *)data, cnt);
savename[cnt] = '\0'; /* Null terminate */
if (auth_debug_mode)
printf(">>>%s: Got NAME [%s]\r\n", Name, savename);
auth_encrypt_user(savename);
}
int
auth_sendname(cp, len)
unsigned char *cp;
int len;
{
static unsigned char str_request[256+6]
= { IAC, SB, TELOPT_AUTHENTICATION, TELQUAL_NAME, };
register unsigned char *e = str_request + 4;
register unsigned char *ee = &str_request[sizeof(str_request)-2];
while (--len >= 0) {
if ((*e++ = *cp++) == IAC)
*e++ = IAC;
if (e >= ee)
return(0);
}
*e++ = IAC;
*e++ = SE;
telnet_net_write(str_request, e - str_request);
printsub('>', &str_request[2], e - &str_request[2]);
return(1);
}
void
auth_finished(ap, result)
Authenticator *ap;
int result;
{
if (!(authenticated = ap))
authenticated = &NoAuth;
validuser = result;
}
/* ARGSUSED */
static void
auth_intr(sig)
int sig;
{
auth_finished(0, AUTH_REJECT);
}
int
auth_wait(name, l)
char *name;
size_t l;
{
if (auth_debug_mode)
printf(">>>%s: in auth_wait.\r\n", Name);
if (Server && !authenticating)
return(0);
(void) signal(SIGALRM, auth_intr);
alarm(30);
while (!authenticated)
if (telnet_spin())
break;
alarm(0);
(void) signal(SIGALRM, SIG_DFL);
/*
* Now check to see if the user is valid or not
*/
if (!authenticated || authenticated == &NoAuth)
return(AUTH_REJECT);
if (validuser == AUTH_VALID)
validuser = AUTH_USER;
if (authenticated->status)
validuser = (*authenticated->status)(authenticated,
name, l, validuser);
return(validuser);
}
void
auth_debug(mode)
int mode;
{
auth_debug_mode = mode;
}
void
auth_printsub(data, cnt, buf, buflen)
unsigned char *data, *buf;
int cnt, buflen;
{
Authenticator *ap;
if ((ap = findauthenticator(data[1], data[2])) && ap->printsub)
(*ap->printsub)(data, cnt, buf, buflen);
else
auth_gen_printsub(data, cnt, buf, buflen);
}
void
auth_gen_printsub(data, cnt, buf, buflen)
unsigned char *data, *buf;
int cnt, buflen;
{
register unsigned char *cp;
unsigned char tbuf[16];
cnt -= 3;
data += 3;
buf[buflen-1] = '\0';
buf[buflen-2] = '*';
buflen -= 2;
for (; cnt > 0; cnt--, data++) {
snprintf((char *)tbuf, sizeof(tbuf), " %d", *data);
for (cp = tbuf; *cp && buflen > 0; --buflen)
*buf++ = *cp++;
if (buflen <= 0)
return;
}
*buf = '\0';
}
#endif