/*-
 * Copyright (c) 1992, 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>

__FBSDID("$FreeBSD$");

#ifndef lint
static char sccsid[] = "@(#)krb4encpwd.c        8.3 (Berkeley) 5/30/95";
#endif /* not lint */


#ifdef  KRB4_ENCPWD
/*
 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
 * ALL RIGHTS RESERVED
 *
 * "Digital Equipment Corporation authorizes the reproduction,
 * distribution and modification of this software subject to the following
 * restrictions:
 *
 * 1.  Any partial or whole copy of this software, or any modification
 * thereof, must include this copyright notice in its entirety.
 *
 * 2.  This software is supplied "as is" with no warranty of any kind,
 * expressed or implied, for any purpose, including any warranty of fitness
 * or merchantibility.  DIGITAL assumes no responsibility for the use or
 * reliability of this software, nor promises to provide any form of
 * support for it on any basis.
 *
 * 3.  Distribution of this software is authorized only if no profit or
 * remuneration of any kind is received in exchange for such distribution.
 *
 * 4.  This software produces public key authentication certificates
 * bearing an expiration date established by DIGITAL and RSA Data
 * Security, Inc.  It may cease to generate certificates after the expiration
 * date.  Any modification of this software that changes or defeats
 * the expiration date or its effect is unauthorized.
 *
 * 5.  Software that will renew or extend the expiration date of
 * authentication certificates produced by this software may be obtained
 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
 * 94065, (415)595-8782, or from DIGITAL"
 *
 */

#include <sys/types.h>
#include <openssl/des.h>
#include <arpa/telnet.h>
#include <krb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "encrypt.h"
#include "auth.h"
#include "misc.h"

int krb_mk_encpwd_req(KTEXT, char *, char *, char *, char *, char *, char *);
int krb_rd_encpwd_req(KTEXT, char *, char *, u_long, AUTH_DAT *, char *, char *, char *, char *);

extern auth_debug_mode;

static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
                                        AUTHTYPE_KRB4_ENCPWD, };
static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
                                        TELQUAL_NAME, };

#define KRB4_ENCPWD_AUTH        0       /* Authentication data follows */
#define KRB4_ENCPWD_REJECT      1       /* Rejected (reason might follow) */
#define KRB4_ENCPWD_ACCEPT      2       /* Accepted */
#define KRB4_ENCPWD_CHALLENGE   3       /* Challenge for mutual auth. */
#define KRB4_ENCPWD_ACK         4       /* Acknowledge */

#define KRB_SERVICE_NAME    "rcmd"

static  KTEXT_ST auth;
static  char name[ANAME_SZ];
static  char user_passwd[ANAME_SZ];
static  AUTH_DAT adat = { 0 };
#ifdef  ENCRYPTION
static Block    session_key     = { 0 };
#endif  /* ENCRYPTION */
static char  challenge[REALM_SZ];

        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 (0) {
                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(net_write(str_data, p - str_data));
}

        int
krb4encpwd_init(ap, server)
        Authenticator *ap;
        int server;
{
        char hostname[80], *cp, *realm;
        C_Block skey;

        if (server) {
                str_data[3] = TELQUAL_REPLY;
        } else {
                str_data[3] = TELQUAL_IS;
                gethostname(hostname, sizeof(hostname));
                realm = krb_realmofhost(hostname);
                cp = strchr(hostname, '.');
                if (*cp != NULL) *cp = NULL;
                if (read_service_key(KRB_SERVICE_NAME, hostname, realm, 0,
                                        KEYFILE, (char *)skey)) {
                  return(0);
                }
        }
        return(1);
}

        int
krb4encpwd_send(ap)
        Authenticator *ap;
{

        printf("[ Trying KRB4ENCPWD ... ]\n");
        if (!UserNameRequested) {
                return(0);
        }
        if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
                return(0);
        }

        if (!Data(ap, KRB4_ENCPWD_ACK, (void *)NULL, 0)) {
                return(0);
        }

        return(1);
}

        void
krb4encpwd_is(ap, data, cnt)
        Authenticator *ap;
        unsigned char *data;
        int cnt;
{
        Session_Key skey;
        Block datablock;
        char  r_passwd[ANAME_SZ], r_user[ANAME_SZ];
        char  lhostname[ANAME_SZ], *cp;
        int r;
        time_t now;

        if (cnt-- < 1)
                return;
        switch (*data++) {
        case KRB4_ENCPWD_AUTH:
                memmove((void *)auth.dat, (void *)data, auth.length = cnt);

                gethostname(lhostname, sizeof(lhostname));
                if ((cp = strchr(lhostname, '.')) != 0)  *cp = '\0';

                if (r = krb_rd_encpwd_req(&auth, KRB_SERVICE_NAME, lhostname, 0, &adat, NULL, challenge, r_user, r_passwd)) {
                        Data(ap, KRB4_ENCPWD_REJECT, (void *)"Auth failed", -1);
                        auth_finished(ap, AUTH_REJECT);
                        return;
                }
                auth_encrypt_userpwd(r_passwd);
                if (passwdok(UserNameRequested, UserPassword) == 0) {
                  /*
                   *  illegal username and password
                   */
                  Data(ap, KRB4_ENCPWD_REJECT, (void *)"Illegal password", -1);
                  auth_finished(ap, AUTH_REJECT);
                  return;
                }

                memmove((void *)session_key, (void *)adat.session, sizeof(Block));
                Data(ap, KRB4_ENCPWD_ACCEPT, (void *)0, 0);
                auth_finished(ap, AUTH_USER);
                break;

        case KRB4_ENCPWD_CHALLENGE:
                /*
                 *  Take the received random challenge text and save
                 *  for future authentication.
                 */
                memmove((void *)challenge, (void *)data, sizeof(Block));
                break;


        case KRB4_ENCPWD_ACK:
                /*
                 *  Receive ack, if mutual then send random challenge
                 */

                /*
                 * 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;

                  time(&now);
                  sprintf(challenge, "%x", now);
                  Data(ap, KRB4_ENCPWD_CHALLENGE, (void *)challenge, strlen(challenge));
                }
                break;

        default:
                Data(ap, KRB4_ENCPWD_REJECT, 0, 0);
                break;
        }
}


        void
krb4encpwd_reply(ap, data, cnt)
        Authenticator *ap;
        unsigned char *data;
        int cnt;
{
        Session_Key skey;
        KTEXT_ST krb_token;
        Block enckey;
        CREDENTIALS cred;
        int r;
        char    randchal[REALM_SZ], instance[ANAME_SZ], *cp;
        char    hostname[80], *realm;

        if (cnt-- < 1)
                return;
        switch (*data++) {
        case KRB4_ENCPWD_REJECT:
                if (cnt > 0) {
                        printf("[ KRB4_ENCPWD refuses authentication because %.*s ]\r\n",
                                cnt, data);
                } else
                        printf("[ KRB4_ENCPWD refuses authentication ]\r\n");
                auth_send_retry();
                return;
        case KRB4_ENCPWD_ACCEPT:
                printf("[ KRB4_ENCPWD accepts you ]\n");
                auth_finished(ap, AUTH_USER);
                return;
        case KRB4_ENCPWD_CHALLENGE:
                /*
                 * Verify that the response to the challenge is correct.
                 */

                gethostname(hostname, sizeof(hostname));
                realm = krb_realmofhost(hostname);
                memmove((void *)challenge, (void *)data, cnt);
                memset(user_passwd, 0, sizeof(user_passwd));
                local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
                UserPassword = user_passwd;
                Challenge = challenge;
                strcpy(instance, RemoteHostName);
                if ((cp = strchr(instance, '.')) != 0)  *cp = '\0';

                if (r = krb_mk_encpwd_req(&krb_token, KRB_SERVICE_NAME, instance, realm, Challenge, UserNameRequested, user_passwd)) {
                  krb_token.length = 0;
                }

                if (!Data(ap, KRB4_ENCPWD_AUTH, (void *)krb_token.dat, krb_token.length)) {
                  return;
                }

                break;

        default:
                return;
        }
}

        int
krb4encpwd_status(ap, name, level)
        Authenticator *ap;
        char *name;
        int level;
{

        if (level < AUTH_USER)
                return(level);

        if (UserNameRequested && passwdok(UserNameRequested, UserPassword)) {
                strcpy(name, 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
krb4encpwd_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 KRB4_ENCPWD_REJECT:        /* Rejected (reason might follow) */
                strncpy((char *)buf, " REJECT ", buflen);
                goto common;

        case KRB4_ENCPWD_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 KRB4_ENCPWD_AUTH:          /* Authentication data follows */
                strncpy((char *)buf, " AUTH", buflen);
                goto common2;

        case KRB4_ENCPWD_CHALLENGE:
                strncpy((char *)buf, " CHALLENGE", buflen);
                goto common2;

        case KRB4_ENCPWD_ACK:
                strncpy((char *)buf, " ACK", 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 passwdok(name, passwd)
char *name, *passwd;
{
  char *crypt();
  char *salt, *p;
  struct passwd *pwd;
  int   passwdok_status = 0;

  if (pwd = getpwnam(name))
    salt = pwd->pw_passwd;
  else salt = "xx";

  p = crypt(passwd, salt);

  if (pwd && !strcmp(p, pwd->pw_passwd)) {
    passwdok_status = 1;
  } else passwdok_status = 0;
  return(passwdok_status);
}

#endif