[unix-history] / usr / src / usr.bin / passwd / krb_passwd.c

/*-
* Copyright (c) 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* %sccs.include.redist.c%
*/

#ifndef lint
static char sccsid[] = "@(#)krb_passwd.c        8.2 (Berkeley) %G%";
#endif /* not lint */

#ifdef KERBEROS

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <netinet/in.h>
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>

#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "kpasswd_proto.h"

#include "extern.h"

#define PROTO   "tcp"

static void     send_update __P((int, char *, char *));
static void     recv_ack __P((int));
static void     cleanup __P((void));
static void     finish __P((void));

static struct timeval timeout = { CLIENT_KRB_TIMEOUT, 0 };
static struct kpasswd_data proto_data;
static des_cblock okey;
static Key_schedule osched;
static KTEXT_ST ticket;
static Key_schedule random_schedule;
static long authopts;
static char realm[REALM_SZ], krbhst[MAX_HSTNM];
static int sock;

int
krb_passwd()
{
       struct servent *se;
       struct hostent *host;
       struct sockaddr_in sin;
       CREDENTIALS cred;
       fd_set readfds;
       int rval;
       char pass[_PASSWORD_LEN], password[_PASSWORD_LEN];
       static void finish();

       static struct rlimit rl = { 0, 0 };

       (void)signal(SIGHUP, SIG_IGN);
       (void)signal(SIGINT, SIG_IGN);
       (void)signal(SIGTSTP, SIG_IGN);

       if (setrlimit(RLIMIT_CORE, &rl) < 0) {
               warn("setrlimit");
               return (1);
       }

       if ((se = getservbyname(SERVICE, PROTO)) == NULL) {
               warnx("couldn't find entry for service %s/%s",
                   SERVICE, PROTO);
               return (1);
       }

       if ((rval = krb_get_lrealm(realm,1)) != KSUCCESS) {
               warnx("couldn't get local Kerberos realm: %s",
                   krb_err_txt[rval]);
               return (1);
       }

       if ((rval = krb_get_krbhst(krbhst, realm, 1)) != KSUCCESS) {
               warnx("couldn't get Kerberos host: %s",
                   krb_err_txt[rval]);
               return (1);
       }

       if ((host = gethostbyname(krbhst)) == NULL) {
               warnx("couldn't get host entry for krb host %s",
                   krbhst);
               return (1);
       }

       sin.sin_family = host->h_addrtype;
       memmove((char *) &sin.sin_addr, host->h_addr, host->h_length);
       sin.sin_port = se->s_port;

       if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
               warn("socket");
               return (1);
       }

       if (connect(sock, (struct sockaddr *) &sin, sizeof(sin)) < 0) {
               warn("connect");
               (void)close(sock);
               return (1);
       }

       rval = krb_sendauth(
               authopts,               /* NOT mutual */
               sock,
               &ticket,                /* (filled in) */
               SERVICE,
               krbhst,                 /* instance (krbhst) */
               realm,                  /* dest realm */
               (u_long) getpid(),      /* checksum */
               NULL,                   /* msg data */
               NULL,                   /* credentials */ 
               NULL,                   /* schedule */
               NULL,                   /* local addr */
               NULL,                   /* foreign addr */
               "KPWDV0.1"
       );

       if (rval != KSUCCESS) {
               warnx("Kerberos sendauth error: %s", krb_err_txt[rval]);
               return (1);
       }

       krb_get_cred("krbtgt", realm, realm, &cred);

       (void)printf("Changing Kerberos password for %s.%s@%s.\n",
           cred.pname, cred.pinst, realm);

       if (des_read_pw_string(pass,
           sizeof(pass)-1, "Old Kerberos password:", 0)) {
               warnx("error reading old Kerberos password");
               return (1);
       }

       (void)des_string_to_key(pass, okey);
       (void)des_key_sched(okey, osched);
       (void)des_set_key(okey, osched);

       /* wait on the verification string */

       FD_ZERO(&readfds);
       FD_SET(sock, &readfds);

       rval =
           select(sock + 1, &readfds, (fd_set *) 0, (fd_set *) 0, &timeout);

       if ((rval < 1) || !FD_ISSET(sock, &readfds)) {
               if(rval == 0) {
                       warnx("timed out (aborted)");
                       cleanup();
                       return (1);
               }
               warnx("select failed (aborted)");
               cleanup();
               return (1);
       }

       /* read verification string */

       if (des_read(sock, &proto_data, sizeof(proto_data)) !=
           sizeof(proto_data)) {
               warnx("couldn't read verification string (aborted)");
               cleanup();
               return (1);
       }

       (void)signal(SIGHUP, finish);
       (void)signal(SIGINT, finish);

       if (strcmp(SECURE_STRING, proto_data.secure_msg) != 0) {
               cleanup();
               /* don't complain loud if user just hit return */
               if (pass == NULL || (!*pass))
                       return (0);
               (void)fprintf(stderr, "Sorry\n");
               return (1);
       }

       (void)des_key_sched(proto_data.random_key, random_schedule);
       (void)des_set_key(proto_data.random_key, random_schedule);
       (void)memset(pass, 0, sizeof(pass));

       if (des_read_pw_string(pass,
           sizeof(pass)-1, "New Kerberos password:", 0)) {
               warnx("error reading new Kerberos password (aborted)");
               cleanup();
               return (1);
       }

       if (des_read_pw_string(password,
           sizeof(password)-1, "Retype new Kerberos password:", 0)) {
               warnx("error reading new Kerberos password (aborted)");
               cleanup();
               return (1);
       }

       if (strcmp(password, pass) != 0) {
               warnx("password mismatch (aborted)");
               cleanup();
               return (1);
       }

       if (strlen(pass) == 0)
               (void)printf("using NULL password\n");

       send_update(sock, password, SECURE_STRING);

       /* wait for ACK */

       FD_ZERO(&readfds);
       FD_SET(sock, &readfds);

       rval =
           select(sock + 1, &readfds, (fd_set *) 0, (fd_set *) 0, &timeout);
       if ((rval < 1) || !FD_ISSET(sock, &readfds)) {
               if(rval == 0) {
                       warnx("timed out reading ACK (aborted)");
                       cleanup();
                       exit(1);
               }
               warnx("select failed (aborted)");
               cleanup();
               exit(1);
       }
       recv_ack(sock);
       cleanup();
       return (0);
}

static void
send_update(dest, pwd, str)
       int dest;
       char *pwd, *str;
{
       static struct update_data ud;

       (void)strncpy(ud.secure_msg, str, _PASSWORD_LEN);
       (void)strncpy(ud.pw, pwd, sizeof(ud.pw));
       if (des_write(dest, &ud, sizeof(ud)) != sizeof(ud)) {
               warnx("couldn't write pw update (abort)");
               memset((char *)&ud, 0, sizeof(ud));
               cleanup();
               exit(1);
       }
}

static void
recv_ack(remote)
       int remote;
{
       int cc;
       char buf[BUFSIZ];

       cc = des_read(remote, buf, sizeof(buf));
       if (cc <= 0) {
               warnx("error reading acknowledgement (aborted)");
               cleanup();
               exit(1);
       }
       (void)printf("%s", buf);
}

static void
cleanup()
{

       (void)memset((char *)&proto_data, 0, sizeof(proto_data));
       (void)memset((char *)okey, 0, sizeof(okey));
       (void)memset((char *)osched, 0, sizeof(osched));
       (void)memset((char *)random_schedule, 0, sizeof(random_schedule));
}

static void
finish()
{

       (void)close(sock);
       exit(1);
}

#endif /* KERBEROS */