diff options
author | markm <markm@FreeBSD.org> | 1997-09-04 06:04:33 +0000 |
---|---|---|
committer | markm <markm@FreeBSD.org> | 1997-09-04 06:04:33 +0000 |
commit | a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8 (patch) | |
tree | 0b84977f19022a965f8c6145f067f951173f6290 /crypto/kerberosIV/appl/bsd/rshd.c | |
download | FreeBSD-src-a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8.zip FreeBSD-src-a8a89cfaf983bc64f4b42f7c35209a5a36dd0fe8.tar.gz |
Initial import of KTH eBones. This has been cleaned up to only include
the "core" Kerberos functionality. The rest of the userland will get their
own changes later.
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); +} |