563 lines
14 KiB
C
563 lines
14 KiB
C
/* $NetBSD: kerberos.c,v 1.6 2001/11/30 04:48:14 lukem 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. 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[] = "@(#)kerberos.c 8.3 (Berkeley) 5/30/95";
|
|
#else
|
|
__RCSID("$NetBSD: kerberos.c,v 1.6 2001/11/30 04:48:14 lukem 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 KRB4
|
|
#include <sys/types.h>
|
|
#include <arpa/telnet.h>
|
|
#include <stdio.h>
|
|
#include <des.h> /* BSD wont include this in krb.h, so we do it here */
|
|
#include <krb.h>
|
|
#ifdef __STDC__
|
|
#include <stdlib.h>
|
|
#endif
|
|
#ifdef NO_STRING_H
|
|
#include <strings.h>
|
|
#else
|
|
#include <string.h>
|
|
#endif
|
|
|
|
#include "encrypt.h"
|
|
#include "auth.h"
|
|
#include "misc.h"
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
int kerberos4_cksum __P((unsigned char *, int));
|
|
|
|
static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
|
|
AUTHTYPE_KERBEROS_V4, };
|
|
#if 0
|
|
static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
|
|
TELQUAL_NAME, };
|
|
#endif
|
|
|
|
#define KRB_AUTH 0 /* Authentication data follows */
|
|
#define KRB_REJECT 1 /* Rejected (reason might follow) */
|
|
#define KRB_ACCEPT 2 /* Accepted */
|
|
#define KRB_CHALLENGE 3 /* Challenge for mutual auth. */
|
|
#define KRB_RESPONSE 4 /* Response for mutual auth. */
|
|
|
|
#define KRB_SERVICE_NAME "rcmd"
|
|
|
|
static char name[ANAME_SZ];
|
|
static AUTH_DAT adat = { 0 };
|
|
#ifdef ENCRYPTION
|
|
static Block session_key = { 0 };
|
|
static Schedule sched;
|
|
static Block challenge = { 0 };
|
|
#endif /* ENCRYPTION */
|
|
|
|
static int Data P((Authenticator *, int, void *, int));
|
|
|
|
static int
|
|
Data(ap, type, d, c)
|
|
Authenticator *ap;
|
|
int type;
|
|
void *d;
|
|
int c;
|
|
{
|
|
unsigned char *p = str_data + 4;
|
|
unsigned char *cd = (unsigned char *)d;
|
|
|
|
if (c == -1)
|
|
c = strlen((char *)cd);
|
|
|
|
if (auth_debug_mode) {
|
|
printf("%s:%d: [%d] (%d)",
|
|
str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
|
|
str_data[3],
|
|
type, c);
|
|
printd(d, c);
|
|
printf("\r\n");
|
|
}
|
|
*p++ = ap->type;
|
|
*p++ = ap->way;
|
|
*p++ = type;
|
|
while (c-- > 0) {
|
|
if ((*p++ = *cd++) == IAC)
|
|
*p++ = IAC;
|
|
}
|
|
*p++ = IAC;
|
|
*p++ = SE;
|
|
if (str_data[3] == TELQUAL_IS)
|
|
printsub('>', &str_data[2], p - (&str_data[2]));
|
|
return(telnet_net_write(str_data, p - str_data));
|
|
}
|
|
|
|
int
|
|
kerberos4_init(ap, server)
|
|
Authenticator *ap;
|
|
int server;
|
|
{
|
|
FILE *fp;
|
|
|
|
if (server) {
|
|
str_data[3] = TELQUAL_REPLY;
|
|
if ((fp = fopen(KEYFILE, "r")) == NULL)
|
|
return(0);
|
|
fclose(fp);
|
|
} else {
|
|
str_data[3] = TELQUAL_IS;
|
|
}
|
|
return(1);
|
|
}
|
|
|
|
char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
|
|
int dst_realm_sz = REALM_SZ;
|
|
|
|
int
|
|
kerberos4_send(ap)
|
|
Authenticator *ap;
|
|
{
|
|
KTEXT_ST auth;
|
|
char instance[INST_SZ];
|
|
char *realm;
|
|
CREDENTIALS cred;
|
|
int r;
|
|
|
|
printf("[ Trying KERBEROS4 ... ]\n");
|
|
if (!UserNameRequested) {
|
|
if (auth_debug_mode) {
|
|
printf("Kerberos V4: no user name supplied\r\n");
|
|
}
|
|
return(0);
|
|
}
|
|
|
|
memset(instance, 0, sizeof(instance));
|
|
|
|
if ((realm = krb_get_phost((char *)RemoteHostName)) != NULL)
|
|
strncpy(instance, realm, sizeof(instance));
|
|
|
|
instance[sizeof(instance)-1] = '\0';
|
|
|
|
realm = dest_realm ? dest_realm : krb_realmofhost((char *)RemoteHostName);
|
|
|
|
if (!realm) {
|
|
printf("Kerberos V4: no realm for %s\r\n", RemoteHostName);
|
|
return(0);
|
|
}
|
|
r = krb_mk_req(&auth, KRB_SERVICE_NAME, instance, realm, 0L);
|
|
if (r) {
|
|
printf("mk_req failed: %s\r\n", krb_err_txt[r]);
|
|
return(0);
|
|
}
|
|
r = krb_get_cred(KRB_SERVICE_NAME, instance, realm, &cred);
|
|
if (r) {
|
|
printf("get_cred failed: %s\r\n", krb_err_txt[r]);
|
|
return(0);
|
|
}
|
|
if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
|
|
if (auth_debug_mode)
|
|
printf("Not enough room for user name\r\n");
|
|
return(0);
|
|
}
|
|
if (auth_debug_mode)
|
|
printf("Sent %d bytes of authentication data\r\n", auth.length);
|
|
if (!Data(ap, KRB_AUTH, (void *)auth.dat, auth.length)) {
|
|
if (auth_debug_mode)
|
|
printf("Not enough room for authentication data\r\n");
|
|
return(0);
|
|
}
|
|
#ifdef ENCRYPTION
|
|
/*
|
|
* If we are doing mutual authentication, get set up to send
|
|
* the challenge, and verify it when the response comes back.
|
|
*/
|
|
if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
|
|
register int i;
|
|
|
|
des_key_sched(&cred.session, sched);
|
|
des_init_random_number_generator(&cred.session);
|
|
des_new_random_key(&session_key);
|
|
des_ecb_encrypt(&session_key, &session_key, sched, 0);
|
|
des_ecb_encrypt(&session_key, &challenge, sched, 0);
|
|
/*
|
|
* Increment the challenge by 1, and encrypt it for
|
|
* later comparison.
|
|
*/
|
|
for (i = 7; i >= 0; --i) {
|
|
register int x;
|
|
x = (unsigned int)challenge[i] + 1;
|
|
challenge[i] = x; /* ignore overflow */
|
|
if (x < 256) /* if no overflow, all done */
|
|
break;
|
|
}
|
|
des_ecb_encrypt(&challenge, &challenge, sched, 1);
|
|
}
|
|
#endif /* ENCRYPTION */
|
|
|
|
if (auth_debug_mode) {
|
|
printf("CK: %d:", kerberos4_cksum(auth.dat, auth.length));
|
|
printd(auth.dat, auth.length);
|
|
printf("\r\n");
|
|
printf("Sent Kerberos V4 credentials to server\r\n");
|
|
}
|
|
return(1);
|
|
}
|
|
|
|
void
|
|
kerberos4_is(ap, data, cnt)
|
|
Authenticator *ap;
|
|
unsigned char *data;
|
|
int cnt;
|
|
{
|
|
#ifdef ENCRYPTION
|
|
Session_Key skey;
|
|
Block datablock;
|
|
#endif /* ENCRYPTION */
|
|
KTEXT_ST auth;
|
|
char realm[REALM_SZ];
|
|
char instance[INST_SZ];
|
|
int r;
|
|
|
|
if (cnt-- < 1)
|
|
return;
|
|
switch (*data++) {
|
|
case KRB_AUTH:
|
|
if (krb_get_lrealm(realm, 1) != KSUCCESS) {
|
|
Data(ap, KRB_REJECT, (void *)"No local V4 Realm.", -1);
|
|
auth_finished(ap, AUTH_REJECT);
|
|
if (auth_debug_mode)
|
|
printf("No local realm\r\n");
|
|
return;
|
|
}
|
|
memmove((void *)auth.dat, (void *)data, auth.length = cnt);
|
|
if (auth_debug_mode) {
|
|
printf("Got %d bytes of authentication data\r\n", cnt);
|
|
printf("CK: %d:", kerberos4_cksum(auth.dat, auth.length));
|
|
printd(auth.dat, auth.length);
|
|
printf("\r\n");
|
|
}
|
|
instance[0] = '*'; instance[1] = 0;
|
|
if ((r = krb_rd_req(&auth, KRB_SERVICE_NAME,
|
|
instance, 0, &adat, "")) != NULL) {
|
|
if (auth_debug_mode)
|
|
printf("Kerberos failed him as %s\r\n", name);
|
|
Data(ap, KRB_REJECT, (void *)krb_err_txt[r], -1);
|
|
auth_finished(ap, AUTH_REJECT);
|
|
return;
|
|
}
|
|
#ifdef ENCRYPTION
|
|
memmove((void *)session_key, (void *)adat.session, sizeof(Block));
|
|
#endif /* ENCRYPTION */
|
|
krb_kntoln(&adat, name);
|
|
|
|
if (UserNameRequested && !kuserok(&adat, UserNameRequested))
|
|
Data(ap, KRB_ACCEPT, (void *)0, 0);
|
|
else
|
|
Data(ap, KRB_REJECT,
|
|
(void *)"user is not authorized", -1);
|
|
auth_finished(ap, AUTH_USER);
|
|
break;
|
|
|
|
case KRB_CHALLENGE:
|
|
#ifndef ENCRYPTION
|
|
Data(ap, KRB_RESPONSE, (void *)0, 0);
|
|
#else /* ENCRYPTION */
|
|
if (!VALIDKEY(session_key)) {
|
|
/*
|
|
* We don't have a valid session key, so just
|
|
* send back a response with an empty session
|
|
* key.
|
|
*/
|
|
Data(ap, KRB_RESPONSE, (void *)0, 0);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Initialize the random number generator since it's
|
|
* used later on by the encryption routine.
|
|
*/
|
|
des_init_random_number_generator(&session_key);
|
|
des_key_sched(&session_key, sched);
|
|
memmove((void *)datablock, (void *)data, sizeof(Block));
|
|
/*
|
|
* Take the received encrypted challenge, and encrypt
|
|
* it again to get a unique session_key for the
|
|
* ENCRYPT option.
|
|
*/
|
|
des_ecb_encrypt(&datablock, &session_key, sched, 1);
|
|
skey.type = SK_DES;
|
|
skey.length = 8;
|
|
skey.data = session_key;
|
|
encrypt_session_key(&skey, 1);
|
|
/*
|
|
* Now decrypt the received encrypted challenge,
|
|
* increment by one, re-encrypt it and send it back.
|
|
*/
|
|
des_ecb_encrypt(&datablock, &challenge, sched, 0);
|
|
for (r = 7; r >= 0; r--) {
|
|
register int t;
|
|
t = (unsigned int)challenge[r] + 1;
|
|
challenge[r] = t; /* ignore overflow */
|
|
if (t < 256) /* if no overflow, all done */
|
|
break;
|
|
}
|
|
des_ecb_encrypt(&challenge, &challenge, sched, 1);
|
|
Data(ap, KRB_RESPONSE, (void *)challenge, sizeof(challenge));
|
|
#endif /* ENCRYPTION */
|
|
break;
|
|
|
|
default:
|
|
if (auth_debug_mode)
|
|
printf("Unknown Kerberos option %d\r\n", data[-1]);
|
|
Data(ap, KRB_REJECT, 0, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
void
|
|
kerberos4_reply(ap, data, cnt)
|
|
Authenticator *ap;
|
|
unsigned char *data;
|
|
int cnt;
|
|
{
|
|
#ifdef ENCRYPTION
|
|
Session_Key skey;
|
|
#endif /* ENCRYPTION */
|
|
|
|
if (cnt-- < 1)
|
|
return;
|
|
switch (*data++) {
|
|
case KRB_REJECT:
|
|
if (cnt > 0) {
|
|
printf("[ Kerberos V4 refuses authentication because %.*s ]\r\n",
|
|
cnt, data);
|
|
} else
|
|
printf("[ Kerberos V4 refuses authentication ]\r\n");
|
|
auth_send_retry();
|
|
return;
|
|
case KRB_ACCEPT:
|
|
printf("[ Kerberos V4 accepts you ]\n");
|
|
if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_MUTUAL) {
|
|
/*
|
|
* Send over the encrypted challenge.
|
|
*/
|
|
#ifndef ENCRYPTION
|
|
Data(ap, KRB_CHALLENGE, (void *)0, 0);
|
|
#else /* ENCRYPTION */
|
|
Data(ap, KRB_CHALLENGE, (void *)session_key,
|
|
sizeof(session_key));
|
|
des_ecb_encrypt(&session_key, &session_key, sched, 1);
|
|
skey.type = SK_DES;
|
|
skey.length = 8;
|
|
skey.data = session_key;
|
|
encrypt_session_key(&skey, 0);
|
|
#endif /* ENCRYPTION */
|
|
return;
|
|
}
|
|
auth_finished(ap, AUTH_USER);
|
|
return;
|
|
case KRB_RESPONSE:
|
|
#ifdef ENCRYPTION
|
|
/*
|
|
* Verify that the response to the challenge is correct.
|
|
*/
|
|
if ((cnt != sizeof(Block)) ||
|
|
(0 != memcmp((void *)data, (void *)challenge,
|
|
sizeof(challenge))))
|
|
{
|
|
#endif /* ENCRYPTION */
|
|
printf("[ Kerberos V4 challenge failed!!! ]\r\n");
|
|
auth_send_retry();
|
|
return;
|
|
#ifdef ENCRYPTION
|
|
}
|
|
printf("[ Kerberos V4 challenge successful ]\r\n");
|
|
auth_finished(ap, AUTH_USER);
|
|
#endif /* ENCRYPTION */
|
|
break;
|
|
default:
|
|
if (auth_debug_mode)
|
|
printf("Unknown Kerberos option %d\r\n", data[-1]);
|
|
return;
|
|
}
|
|
}
|
|
|
|
int
|
|
kerberos4_status(ap, kname, level)
|
|
Authenticator *ap;
|
|
char *kname;
|
|
int level;
|
|
{
|
|
if (level < AUTH_USER)
|
|
return(level);
|
|
|
|
if (UserNameRequested && !kuserok(&adat, UserNameRequested)) {
|
|
strcpy(kname, UserNameRequested);
|
|
return(AUTH_VALID);
|
|
} else
|
|
return(AUTH_USER);
|
|
}
|
|
|
|
#define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
|
|
#define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
|
|
|
|
void
|
|
kerberos4_printsub(data, cnt, buf, buflen)
|
|
unsigned char *data, *buf;
|
|
int cnt, buflen;
|
|
{
|
|
char lbuf[32];
|
|
register int i;
|
|
|
|
buf[buflen-1] = '\0'; /* make sure its NULL terminated */
|
|
buflen -= 1;
|
|
|
|
switch(data[3]) {
|
|
case KRB_REJECT: /* Rejected (reason might follow) */
|
|
strncpy((char *)buf, " REJECT ", buflen);
|
|
goto common;
|
|
|
|
case KRB_ACCEPT: /* Accepted (name might follow) */
|
|
strncpy((char *)buf, " ACCEPT ", buflen);
|
|
common:
|
|
BUMP(buf, buflen);
|
|
if (cnt <= 4)
|
|
break;
|
|
ADDC(buf, buflen, '"');
|
|
for (i = 4; i < cnt; i++)
|
|
ADDC(buf, buflen, data[i]);
|
|
ADDC(buf, buflen, '"');
|
|
ADDC(buf, buflen, '\0');
|
|
break;
|
|
|
|
case KRB_AUTH: /* Authentication data follows */
|
|
strncpy((char *)buf, " AUTH", buflen);
|
|
goto common2;
|
|
|
|
case KRB_CHALLENGE:
|
|
strncpy((char *)buf, " CHALLENGE", buflen);
|
|
goto common2;
|
|
|
|
case KRB_RESPONSE:
|
|
strncpy((char *)buf, " RESPONSE", buflen);
|
|
goto common2;
|
|
|
|
default:
|
|
sprintf(lbuf, " %d (unknown)", data[3]);
|
|
strncpy((char *)buf, lbuf, buflen);
|
|
common2:
|
|
BUMP(buf, buflen);
|
|
for (i = 4; i < cnt; i++) {
|
|
sprintf(lbuf, " %d", data[i]);
|
|
strncpy((char *)buf, lbuf, buflen);
|
|
BUMP(buf, buflen);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
int
|
|
kerberos4_cksum(d, n)
|
|
unsigned char *d;
|
|
int n;
|
|
{
|
|
int ck = 0;
|
|
|
|
/*
|
|
* A comment is probably needed here for those not
|
|
* well versed in the "C" language. Yes, this is
|
|
* supposed to be a "switch" with the body of the
|
|
* "switch" being a "while" statement. The whole
|
|
* purpose of the switch is to allow us to jump into
|
|
* the middle of the while() loop, and then not have
|
|
* to do any more switch()s.
|
|
*
|
|
* Some compilers will spit out a warning message
|
|
* about the loop not being entered at the top.
|
|
*/
|
|
switch (n&03)
|
|
while (n > 0) {
|
|
case 0:
|
|
ck ^= (int)*d++ << 24;
|
|
--n;
|
|
case 3:
|
|
ck ^= (int)*d++ << 16;
|
|
--n;
|
|
case 2:
|
|
ck ^= (int)*d++ << 8;
|
|
--n;
|
|
case 1:
|
|
ck ^= (int)*d++;
|
|
--n;
|
|
}
|
|
return(ck);
|
|
}
|
|
#endif
|
|
|
|
#ifdef notdef
|
|
|
|
prkey(msg, key)
|
|
char *msg;
|
|
unsigned char *key;
|
|
{
|
|
register int i;
|
|
printf("%s:", msg);
|
|
for (i = 0; i < 8; i++)
|
|
printf(" %3d", key[i]);
|
|
printf("\r\n");
|
|
}
|
|
#endif
|