diff options
Diffstat (limited to 'crypto/kerberosIV/appl/bsd/rshd.c')
| -rw-r--r-- | crypto/kerberosIV/appl/bsd/rshd.c | 635 |
1 files changed, 635 insertions, 0 deletions
diff --git a/crypto/kerberosIV/appl/bsd/rshd.c b/crypto/kerberosIV/appl/bsd/rshd.c new file mode 100644 index 0000000..75ca1df --- /dev/null +++ b/crypto/kerberosIV/appl/bsd/rshd.c @@ -0,0 +1,635 @@ +/*- + * Copyright (c) 1988, 1989, 1992, 1993, 1994 + * 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. + */ + +/* + * remote shell server: + * [port]\0 + * remuser\0 + * locuser\0 + * command\0 + * data + */ + +#include "bsd_locl.h" + +RCSID("$Id: rshd.c,v 1.51 1997/05/13 09:42:39 bg Exp $"); + +extern char *__rcmd_errstr; /* syslog hook from libc/net/rcmd.c. */ +extern int __check_rhosts_file; + +static int keepalive = 1; +static int log_success; /* If TRUE, log all successful accesses */ +static int new_pag = 1; /* Put process in new PAG by default */ +static int no_inetd = 0; +static int sent_null; + +static void doit (struct sockaddr_in *); +static void error (const char *, ...) +#ifdef __GNUC__ +__attribute__ ((format (printf, 1, 2))) +#endif +; +static void usage (void); + +#define VERSION_SIZE 9 +#define SECURE_MESSAGE "This rsh session is using DES encryption for all transmissions.\r\n" +#define OPTIONS "alnkvxLp:Pi" +AUTH_DAT authbuf; +KTEXT_ST tickbuf; +int doencrypt, use_kerberos, vacuous; +Key_schedule schedule; + +int +main(int argc, char *argv[]) +{ + struct linger linger; + int ch, on = 1, fromlen; + struct sockaddr_in from; + int portnum = 0; + + set_progname(argv[0]); + + openlog("rshd", LOG_PID | LOG_ODELAY, LOG_DAEMON); + + opterr = 0; + while ((ch = getopt(argc, argv, OPTIONS)) != EOF) + switch (ch) { + case 'a': + break; + case 'l': + __check_rhosts_file = 0; + break; + case 'n': + keepalive = 0; + break; + case 'k': + use_kerberos = 1; + break; + + case 'v': + vacuous = 1; + break; + + case 'x': + doencrypt = 1; + break; + case 'L': + log_success = 1; + break; + case 'p': + portnum = htons(atoi(optarg)); + break; + case 'P': + new_pag = 0; + break; + case 'i': + no_inetd = 1; + break; + case '?': + default: + usage(); + break; + } + + argc -= optind; + argv += optind; + + if (use_kerberos && vacuous) { + syslog(LOG_ERR, "only one of -k and -v allowed"); + exit(2); + } + if (doencrypt && !use_kerberos) { + syslog(LOG_ERR, "-k is required for -x"); + exit(2); + } + + if (no_inetd) { + if(portnum == 0) + portnum = get_shell_port (use_kerberos, doencrypt); + mini_inetd (portnum); + } + + fromlen = sizeof (from); + if (getpeername(0, (struct sockaddr *)&from, &fromlen) < 0) { + syslog(LOG_ERR, "getpeername: %m"); + _exit(1); + } +#ifdef HAVE_SETSOCKOPT +#ifdef SO_KEEPALIVE + if (keepalive && + setsockopt(0, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, + sizeof(on)) < 0) + syslog(LOG_WARNING, "setsockopt (SO_KEEPALIVE): %m"); +#endif +#ifdef SO_LINGER + linger.l_onoff = 1; + linger.l_linger = 60; /* XXX */ + if (setsockopt(0, SOL_SOCKET, SO_LINGER, (void *)&linger, + sizeof (linger)) < 0) + syslog(LOG_WARNING, "setsockopt (SO_LINGER): %m"); +#endif +#endif /* HAVE_SETSOCKOPT */ + doit(&from); + /* NOTREACHED */ + return 0; +} + +char username[20] = "USER="; +char homedir[64] = "HOME="; +char shell[64] = "SHELL="; +char path[100] = "PATH="; +char *envinit[] = +{homedir, shell, path, username, 0}; + +static void +xgetstr(char *buf, int cnt, char *err) +{ + char c; + + do { + if (read(STDIN_FILENO, &c, 1) != 1) + exit(1); + *buf++ = c; + if (--cnt == 0) { + error("%s too long\n", err); + exit(1); + } + } while (c != 0); +} + +static void +doit(struct sockaddr_in *fromp) +{ + struct passwd *pwd; + u_short port; + fd_set ready, readfrom; + int cc, nfd, pv[2], pid, s; + int one = 1; + const char *errorhost = ""; + char *errorstr; + char *cp, sig, buf[BUFSIZ]; + char cmdbuf[NCARGS+1], locuser[16], remuser[16]; + char remotehost[2 * MaxHostNameLen + 1]; + + AUTH_DAT *kdata; + KTEXT ticket; + char instance[INST_SZ], version[VERSION_SIZE]; + struct sockaddr_in fromaddr; + int rc; + long authopts; + int pv1[2], pv2[2]; + fd_set wready, writeto; + + fromaddr = *fromp; + + signal(SIGINT, SIG_DFL); + signal(SIGQUIT, SIG_DFL); + signal(SIGTERM, SIG_DFL); +#ifdef DEBUG + { int t = open(_PATH_TTY, 2); + if (t >= 0) { + ioctl(t, TIOCNOTTY, (char *)0); + close(t); + } + } +#endif + fromp->sin_port = ntohs((u_short)fromp->sin_port); + if (fromp->sin_family != AF_INET) { + syslog(LOG_ERR, "malformed \"from\" address (af %d)\n", + fromp->sin_family); + exit(1); + } + + + if (!use_kerberos) { + ip_options_and_die (0, fromp); + if (fromp->sin_port >= IPPORT_RESERVED || + fromp->sin_port < IPPORT_RESERVED/2) { + syslog(LOG_NOTICE|LOG_AUTH, + "Connection from %s on illegal port %u", + inet_ntoa(fromp->sin_addr), + fromp->sin_port); + exit(1); + } + } + + alarm(60); + port = 0; + for (;;) { + char c; + if ((cc = read(STDIN_FILENO, &c, 1)) != 1) { + if (cc < 0) + syslog(LOG_NOTICE, "read: %m"); + shutdown(0, 1+1); + exit(1); + } + if (c== 0) + break; + port = port * 10 + c - '0'; + } + + alarm(0); + if (port != 0) { + int lport = IPPORT_RESERVED - 1; + s = rresvport(&lport); + if (s < 0) { + syslog(LOG_ERR, "can't get stderr port: %m"); + exit(1); + } + if (!use_kerberos) + if (port >= IPPORT_RESERVED) { + syslog(LOG_ERR, "2nd port not reserved\n"); + exit(1); + } + fromp->sin_port = htons(port); + if (connect(s, (struct sockaddr *)fromp, sizeof (*fromp)) < 0) { + syslog(LOG_INFO, "connect second port %d: %m", port); + exit(1); + } + } + + if (vacuous) { + error("rshd: remote host requires Kerberos authentication\n"); + exit(1); + } + + errorstr = NULL; + inaddr2str (fromp->sin_addr, remotehost, sizeof(remotehost)); + + if (use_kerberos) { + kdata = &authbuf; + ticket = &tickbuf; + authopts = 0L; + k_getsockinst(0, instance, sizeof(instance)); + version[VERSION_SIZE - 1] = '\0'; + if (doencrypt) { + struct sockaddr_in local_addr; + rc = sizeof(local_addr); + if (getsockname(0, (struct sockaddr *)&local_addr, + &rc) < 0) { + syslog(LOG_ERR, "getsockname: %m"); + error("rlogind: getsockname: %m"); + exit(1); + } + authopts = KOPT_DO_MUTUAL; + rc = krb_recvauth(authopts, 0, ticket, + "rcmd", instance, &fromaddr, + &local_addr, kdata, "", schedule, + version); +#ifndef NOENCRYPTION + des_set_key(&kdata->session, schedule); +#else + memset(schedule, 0, sizeof(schedule)); +#endif + } else + rc = krb_recvauth(authopts, 0, ticket, "rcmd", + instance, &fromaddr, + (struct sockaddr_in *) 0, + kdata, "", 0, version); + if (rc != KSUCCESS) { + error("Kerberos authentication failure: %s\n", + krb_get_err_text(rc)); + exit(1); + } + } else + xgetstr(remuser, sizeof(remuser), "remuser"); + + xgetstr(locuser, sizeof(locuser), "locuser"); + xgetstr(cmdbuf, sizeof(cmdbuf), "command"); + setpwent(); + pwd = k_getpwnam(locuser); + if (pwd == NULL) { + syslog(LOG_INFO|LOG_AUTH, + "%s@%s as %s: unknown login. cmd='%.80s'", + remuser, remotehost, locuser, cmdbuf); + if (errorstr == NULL) + errorstr = "Login incorrect.\n"; + goto fail; + } + if (pwd->pw_uid == 0 && strcmp("root", locuser) != 0) + { + syslog(LOG_ALERT, "NIS attack, user %s has uid 0", locuser); + if (errorstr == NULL) + errorstr = "Login incorrect.\n"; + goto fail; + } + if (chdir(pwd->pw_dir) < 0) { + chdir("/"); +#ifdef notdef + syslog(LOG_INFO|LOG_AUTH, + "%s@%s as %s: no home directory. cmd='%.80s'", + remuser, remotehost, locuser, cmdbuf); + error("No remote directory.\n"); + exit(1); +#endif + } + + if (use_kerberos) { + if (pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0') { + if (kuserok(kdata, locuser) != 0) { + syslog(LOG_INFO|LOG_AUTH, + "Kerberos rsh denied to %s", + krb_unparse_name_long(kdata->pname, + kdata->pinst, + kdata->prealm)); + error("Permission denied.\n"); + exit(1); + } + } + } else + + if (errorstr || + pwd->pw_passwd != 0 && *pwd->pw_passwd != '\0' && + iruserok(fromp->sin_addr.s_addr, pwd->pw_uid == 0, + remuser, locuser) < 0) { + if (__rcmd_errstr) + syslog(LOG_INFO|LOG_AUTH, + "%s@%s as %s: permission denied (%s). cmd='%.80s'", + remuser, remotehost, locuser, + __rcmd_errstr, cmdbuf); + else + syslog(LOG_INFO|LOG_AUTH, + "%s@%s as %s: permission denied. cmd='%.80s'", + remuser, remotehost, locuser, cmdbuf); + fail: + if (errorstr == NULL) + errorstr = "Permission denied.\n"; + error(errorstr, errorhost); + exit(1); + } + + if (pwd->pw_uid && !access(_PATH_NOLOGIN, F_OK)) { + error("Logins currently disabled.\n"); + exit(1); + } + + write(STDERR_FILENO, "\0", 1); + sent_null = 1; + + if (port) { + if (pipe(pv) < 0) { + error("Can't make pipe.\n"); + exit(1); + } + if (doencrypt) { + if (pipe(pv1) < 0) { + error("Can't make 2nd pipe.\n"); + exit(1); + } + if (pipe(pv2) < 0) { + error("Can't make 3rd pipe.\n"); + exit(1); + } + } + pid = fork(); + if (pid == -1) { + error("Can't fork; try again.\n"); + exit(1); + } + if (pid) { + if (doencrypt) { + static char msg[] = SECURE_MESSAGE; + close(pv1[1]); + close(pv2[0]); +#ifndef NOENCRYPTION + des_enc_write(s, msg, sizeof(msg) - 1, schedule, &kdata->session); +#else + write(s, msg, sizeof(msg) - 1); +#endif + } else { + close(0); + close(1); + } + close(2); + close(pv[1]); + + FD_ZERO(&readfrom); + FD_SET(s, &readfrom); + FD_SET(pv[0], &readfrom); + if (pv[0] > s) + nfd = pv[0]; + else + nfd = s; + if (doencrypt) { + FD_ZERO(&writeto); + FD_SET(pv2[1], &writeto); + FD_SET(pv1[0], &readfrom); + FD_SET(STDIN_FILENO, &readfrom); + + nfd = max(nfd, pv2[1]); + nfd = max(nfd, pv1[0]); + } else + ioctl(pv[0], FIONBIO, (char *)&one); + + /* should set s nbio! */ + nfd++; + do { + ready = readfrom; + if (doencrypt) { + wready = writeto; + if (select(nfd, &ready, + &wready, 0, + (struct timeval *) 0) < 0) + break; + } else + if (select(nfd, &ready, 0, + 0, (struct timeval *)0) < 0) + break; + if (FD_ISSET(s, &ready)) { + int ret; + if (doencrypt) +#ifndef NOENCRYPTION + ret = des_enc_read(s, &sig, 1, schedule, &kdata->session); +#else + ret = read(s, &sig, 1); +#endif + else + ret = read(s, &sig, 1); + if (ret <= 0) + FD_CLR(s, &readfrom); + else + kill(-pid, sig); + } + if (FD_ISSET(pv[0], &ready)) { + errno = 0; + cc = read(pv[0], buf, sizeof(buf)); + if (cc <= 0) { + shutdown(s, 1+1); + FD_CLR(pv[0], &readfrom); + } else { + if (doencrypt) +#ifndef NOENCRYPTION + des_enc_write(s, buf, cc, schedule, &kdata->session); +#else + write(s, buf, cc); +#endif + else + (void) + write(s, buf, cc); + } + } + if (doencrypt && FD_ISSET(pv1[0], &ready)) { + errno = 0; + cc = read(pv1[0], buf, sizeof(buf)); + if (cc <= 0) { + shutdown(pv1[0], 1+1); + FD_CLR(pv1[0], &readfrom); + } else +#ifndef NOENCRYPTION + des_enc_write(STDOUT_FILENO, buf, cc, schedule, &kdata->session); +#else + write(STDOUT_FILENO, buf, cc); +#endif + } + + if (doencrypt + && FD_ISSET(STDIN_FILENO, &ready) + && FD_ISSET(pv2[1], &wready)) { + errno = 0; +#ifndef NOENCRYPTION + cc = des_enc_read(STDIN_FILENO, buf, sizeof(buf), schedule, &kdata->session); +#else + cc = read(STDIN_FILENO, buf, sizeof(buf)); +#endif + if (cc <= 0) { + shutdown(STDIN_FILENO, 0); + FD_CLR(STDIN_FILENO, &readfrom); + close(pv2[1]); + FD_CLR(pv2[1], &writeto); + } else + write(pv2[1], buf, cc); + } + + } while (FD_ISSET(s, &readfrom) || + (doencrypt && FD_ISSET(pv1[0], &readfrom)) || + FD_ISSET(pv[0], &readfrom)); + exit(0); + } + setsid(); + close(s); + close(pv[0]); + if (doencrypt) { + close(pv1[0]); + close(pv2[1]); + dup2(pv1[1], 1); + dup2(pv2[0], 0); + close(pv1[1]); + close(pv2[0]); + } + dup2(pv[1], 2); + close(pv[1]); + } + if (*pwd->pw_shell == '\0') + pwd->pw_shell = _PATH_BSHELL; +#ifdef HAVE_SETLOGIN + if (setlogin(pwd->pw_name) < 0) + syslog(LOG_ERR, "setlogin() failed: %m"); +#endif + +#ifdef HAVE_SETPCRED + if (setpcred (pwd->pw_name, NULL) == -1) + syslog(LOG_ERR, "setpcred() failure: %m"); +#endif /* HAVE_SETPCRED */ + setgid((gid_t)pwd->pw_gid); + initgroups(pwd->pw_name, pwd->pw_gid); + setuid((uid_t)pwd->pw_uid); + strncat(homedir, pwd->pw_dir, sizeof(homedir)-6); + + /* Need to extend path to find rcp */ + strncat(path, BINDIR, sizeof(path)-1); + strncat(path, ":", sizeof(path)-1); + strncat(path, _PATH_DEFPATH, sizeof(path)-1); + path[sizeof(path)-1] = '\0'; + + strncat(shell, pwd->pw_shell, sizeof(shell)-7); + strncat(username, pwd->pw_name, sizeof(username)-6); + cp = strrchr(pwd->pw_shell, '/'); + if (cp) + cp++; + else + cp = pwd->pw_shell; + endpwent(); + if (log_success || pwd->pw_uid == 0) { + if (use_kerberos) + syslog(LOG_INFO|LOG_AUTH, + "Kerberos shell from %s on %s as %s, cmd='%.80s'", + krb_unparse_name_long(kdata->pname, + kdata->pinst, + kdata->prealm), + remotehost, locuser, cmdbuf); + else + syslog(LOG_INFO|LOG_AUTH, "%s@%s as %s: cmd='%.80s'", + remuser, remotehost, locuser, cmdbuf); + } + if (k_hasafs()) { + if (new_pag) + k_setpag(); /* Put users process in an new pag */ + k_afsklog(0, 0); + } + execle(pwd->pw_shell, cp, "-c", cmdbuf, 0, envinit); + err(1, pwd->pw_shell); +} + +/* + * Report error to client. Note: can't be used until second socket has + * connected to client, or older clients will hang waiting for that + * connection first. + */ + +static void +error(const char *fmt, ...) +{ + va_list ap; + int len; + char *bp, buf[BUFSIZ]; + + va_start(ap, fmt); + bp = buf; + if (sent_null == 0) { + *bp++ = 1; + len = 1; + } else + len = 0; + len = vsnprintf (bp, sizeof(buf) - len, fmt, ap); + write (STDERR_FILENO, buf, len); + va_end(ap); +} + +static void +usage() +{ + + syslog(LOG_ERR, + "usage: rshd [-alnkvxLPi] [-p port]"); + exit(2); +} |
