-/* $OpenBSD: session.c,v 1.221 2007/01/21 01:41:54 stevesk Exp $ */
+/* $OpenBSD: session.c,v 1.233 2008/03/26 21:28:14 djm Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
#include "sshlogin.h"
#include "serverloop.h"
#include "canohost.h"
+#include "misc.h"
#include "session.h"
#include "kex.h"
#include "monitor_wrap.h"
+#include "sftp.h"
#if defined(KRB5) && defined(USE_AFS)
#include <kafs.h>
const char *original_command = NULL;
/* data */
-#define MAX_SESSIONS 10
+#define MAX_SESSIONS 20
Session sessions[MAX_SESSIONS];
+#define SUBSYSTEM_NONE 0
+#define SUBSYSTEM_EXT 1
+#define SUBSYSTEM_INT_SFTP 2
+
#ifdef HAVE_LOGIN_CAP
login_cap_t *lc;
#endif
session_proctitle(s);
-#if defined(USE_PAM)
- if (options.use_pam && !use_privsep)
- do_pam_setcred(1);
-#endif /* USE_PAM */
-
/* Fork the child. */
if ((pid = fork()) == 0) {
is_child = 1;
ptyfd = s->ptyfd;
ttyfd = s->ttyfd;
-#if defined(USE_PAM)
- if (options.use_pam) {
- do_pam_set_tty(s->tty);
- if (!use_privsep)
- do_pam_setcred(1);
- }
-#endif
-
/* Fork the child. */
if ((pid = fork()) == 0) {
is_child = 1;
if (options.adm_forced_command) {
original_command = command;
command = options.adm_forced_command;
+ if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
+ s->is_subsystem = SUBSYSTEM_INT_SFTP;
+ else if (s->is_subsystem)
+ s->is_subsystem = SUBSYSTEM_EXT;
debug("Forced command (config) '%.900s'", command);
} else if (forced_command) {
original_command = command;
command = forced_command;
+ if (strcmp(INTERNAL_SFTP_NAME, command) == 0)
+ s->is_subsystem = SUBSYSTEM_INT_SFTP;
+ else if (s->is_subsystem)
+ s->is_subsystem = SUBSYSTEM_EXT;
debug("Forced command (key option) '%.900s'", command);
}
PRIVSEP(audit_run_command(shell));
}
#endif
-
if (s->ttyfd != -1)
do_exec_pty(s, command);
else
;
if (!*cp || *cp == '#' || *cp == '\n')
continue;
- if (strchr(cp, '\n'))
- *strchr(cp, '\n') = '\0';
+
+ cp[strcspn(cp, "\n")] = '\0';
+
value = strchr(cp, '=');
if (value == NULL) {
fprintf(stderr, "Bad line %u in %.100s\n", lineno,
do_xauth =
s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
- /* ignore _PATH_SSH_USER_RC for subsystems */
- if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
+ /* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
+ if (!s->is_subsystem && options.adm_forced_command == NULL &&
+ !no_user_rc && (stat(_PATH_SSH_USER_RC, &st) >= 0)) {
snprintf(cmd, sizeof cmd, "%s -c '%s %s'",
shell, _PATH_BSHELL, _PATH_SSH_USER_RC);
if (debug_flag)
}
}
+/*
+ * Chroot into a directory after checking it for safety: all path components
+ * must be root-owned directories with strict permissions.
+ */
+static void
+safely_chroot(const char *path, uid_t uid)
+{
+ const char *cp;
+ char component[MAXPATHLEN];
+ struct stat st;
+
+ if (*path != '/')
+ fatal("chroot path does not begin at root");
+ if (strlen(path) >= sizeof(component))
+ fatal("chroot path too long");
+
+ /*
+ * Descend the path, checking that each component is a
+ * root-owned directory with strict permissions.
+ */
+ for (cp = path; cp != NULL;) {
+ if ((cp = strchr(cp, '/')) == NULL)
+ strlcpy(component, path, sizeof(component));
+ else {
+ cp++;
+ memcpy(component, path, cp - path);
+ component[cp - path] = '\0';
+ }
+
+ debug3("%s: checking '%s'", __func__, component);
+
+ if (stat(component, &st) != 0)
+ fatal("%s: stat(\"%s\"): %s", __func__,
+ component, strerror(errno));
+ if (st.st_uid != 0 || (st.st_mode & 022) != 0)
+ fatal("bad ownership or modes for chroot "
+ "directory %s\"%s\"",
+ cp == NULL ? "" : "component ", component);
+ if (!S_ISDIR(st.st_mode))
+ fatal("chroot path %s\"%s\" is not a directory",
+ cp == NULL ? "" : "component ", component);
+
+ }
+
+ if (chdir(path) == -1)
+ fatal("Unable to chdir to chroot path \"%s\": "
+ "%s", path, strerror(errno));
+ if (chroot(path) == -1)
+ fatal("chroot(\"%s\"): %s", path, strerror(errno));
+ if (chdir("/") == -1)
+ fatal("%s: chdir(/) after chroot: %s",
+ __func__, strerror(errno));
+ verbose("Changed root directory to \"%s\"", path);
+}
+
/* Set login name, uid, gid, and groups. */
void
do_setusercontext(struct passwd *pw)
{
+ char *chroot_path, *tmp;
+
+#ifdef WITH_SELINUX
+ /* Cache selinux status for later use */
+ (void)ssh_selinux_enabled();
+#endif
+
#ifndef HAVE_CYGWIN
if (getuid() == 0 || geteuid() == 0)
#endif /* HAVE_CYGWIN */
# ifdef __bsdi__
setpgid(0, 0);
# endif
-#ifdef GSSAPI
- if (options.gss_authentication) {
- temporarily_use_uid(pw);
- ssh_gssapi_storecreds();
- restore_uid();
- }
-#endif
# ifdef USE_PAM
if (options.use_pam) {
- do_pam_session();
do_pam_setcred(use_privsep);
}
# endif /* USE_PAM */
if (setusercontext(lc, pw, pw->pw_uid,
- (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
+ (LOGIN_SETALL & ~(LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
perror("unable to set user context");
exit(1);
}
exit(1);
}
endgrent();
-#ifdef GSSAPI
- if (options.gss_authentication) {
- temporarily_use_uid(pw);
- ssh_gssapi_storecreds();
- restore_uid();
- }
-#endif
# ifdef USE_PAM
/*
* PAM credentials may take the form of supplementary groups.
* Reestablish them here.
*/
if (options.use_pam) {
- do_pam_session();
do_pam_setcred(use_privsep);
}
# endif /* USE_PAM */
# if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
irix_setusercontext(pw);
-# endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
+# endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
# ifdef _AIX
aix_usrinfo(pw);
# endif /* _AIX */
-#ifdef USE_LIBIAF
+# ifdef USE_LIBIAF
if (set_id(pw->pw_name) != 0) {
exit(1);
}
-#endif /* USE_LIBIAF */
+# endif /* USE_LIBIAF */
+#endif
+
+ if (options.chroot_directory != NULL &&
+ strcasecmp(options.chroot_directory, "none") != 0) {
+ tmp = tilde_expand_filename(options.chroot_directory,
+ pw->pw_uid);
+ chroot_path = percent_expand(tmp, "h", pw->pw_dir,
+ "u", pw->pw_name, (char *)NULL);
+ safely_chroot(chroot_path, pw->pw_uid);
+ free(tmp);
+ free(chroot_path);
+ }
+
+#ifdef HAVE_LOGIN_CAP
+ if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
+ perror("unable to set user context (setuser)");
+ exit(1);
+ }
+#else
/* Permanently switch to the desired uid. */
permanently_set_uid(pw);
#endif
* environment, closing extra file descriptors, setting the user and group
* ids, and executing the command or shell.
*/
+#define ARGV_MAX 10
void
do_child(Session *s, const char *command)
{
extern char **environ;
char **env;
- char *argv[10];
+ char *argv[ARGV_MAX];
const char *shell, *shell0, *hostname = NULL;
struct passwd *pw = s->pw;
#endif
}
+ closefrom(STDERR_FILENO + 1);
+
if (!options.use_login)
do_rc_files(s, shell);
/* restore SIGPIPE for child */
signal(SIGPIPE, SIG_DFL);
+ if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
+ extern int optind, optreset;
+ int i;
+ char *p, *args;
+
+ setproctitle("%s@internal-sftp-server", s->pw->pw_name);
+ args = strdup(command ? command : "sftp-server");
+ for (i = 0, (p = strtok(args, " ")); p; (p = strtok(NULL, " ")))
+ if (i < ARGV_MAX - 1)
+ argv[i++] = p;
+ argv[i] = NULL;
+ optind = optreset = 1;
+ __progname = argv[0];
+ exit(sftp_server_main(i, argv, s->pw));
+ }
+
if (options.use_login) {
launch_login(pw, hostname);
/* NEVERREACHED */
if (strcmp(subsys, options.subsystem_name[i]) == 0) {
prog = options.subsystem_command[i];
cmd = options.subsystem_args[i];
- if (stat(prog, &st) < 0) {
+ if (!strcmp(INTERNAL_SFTP_NAME, prog)) {
+ s->is_subsystem = SUBSYSTEM_INT_SFTP;
+ } else if (stat(prog, &st) < 0) {
error("subsystem: cannot stat %s: %s", prog,
strerror(errno));
break;
+ } else {
+ s->is_subsystem = SUBSYSTEM_EXT;
}
debug("subsystem: exec() %s", cmd);
- s->is_subsystem = 1;
do_exec(s, cmd);
success = 1;
break;
channel_request_start(s->chanid, "exit-signal", 0);
packet_put_cstring(sig2name(WTERMSIG(status)));
#ifdef WCOREDUMP
- packet_put_char(WCOREDUMP(status));
+ packet_put_char(WCOREDUMP(status)? 1 : 0);
#else /* WCOREDUMP */
packet_put_char(0);
#endif /* WCOREDUMP */
andersk / gssapi-openssh.git / blobdiff