-/* $OpenBSD: session.c,v 1.203 2006/04/20 21:53:44 djm Exp $ */
+/* $OpenBSD: session.c,v 1.230 2008/02/22 05:58:56 djm Exp $ */
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
#include "includes.h"
#include <sys/types.h>
+#include <sys/param.h>
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif
-#include <sys/wait.h>
+#include <sys/socket.h>
#include <sys/un.h>
+#include <sys/wait.h>
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <grp.h>
#ifdef HAVE_PATHS_H
#include <paths.h>
#endif
+#include <pwd.h>
#include <signal.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "xmalloc.h"
#include "ssh.h"
#include "ssh1.h"
#include "ssh2.h"
-#include "xmalloc.h"
#include "sshpty.h"
#include "packet.h"
#include "buffer.h"
#include "uidswap.h"
#include "compat.h"
#include "channels.h"
-#include "bufaux.h"
+#include "key.h"
+#include "cipher.h"
+#ifdef GSSAPI
+#include "ssh-gss.h"
+#endif
+#include "hostfile.h"
#include "auth.h"
#include "auth-options.h"
#include "pathnames.h"
#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>
#endif
-#ifdef GSSAPI
-#include "ssh-gss.h"
-#endif
-
/* func */
Session *session_new(void);
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
break;
}
debug("Received TCP/IP port forwarding request.");
- channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports);
+ if (channel_input_port_forward_request(s->pw->pw_uid == 0,
+ options.gateway_ports) < 0) {
+ debug("Port forwarding failed.");
+ break;
+ }
success = 1;
break;
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;
void
do_exec(Session *s, const char *command)
{
- if (forced_command) {
+ 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;
- debug("Forced command '%.900s'", 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);
}
#ifdef SSH_AUDIT_EVENTS
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,
{
char buf[256];
u_int i, envsize;
- char **env, *laddr, *path = NULL;
+ char **env, *laddr;
struct passwd *pw = s->pw;
+#ifndef HAVE_LOGIN_CAP
+ char *path = NULL;
+#endif
/* Initialize the environment. */
envsize = 100;
- env = xmalloc(envsize * sizeof(char *));
+ env = xcalloc(envsize, sizeof(char *));
env[0] = NULL;
#ifdef HAVE_CYGWIN
}
}
+/*
+ * 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);
+
+ }
+
+ closefrom(STDERR_FILENO + 1);
+
+ 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;
+
#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(0);
+ 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(0);
+ 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 */
-#if defined(HAVE_LIBIAF) && !defined(BROKEN_LIBIAF)
+# ifdef USE_LIBIAF
if (set_id(pw->pw_name) != 0) {
exit(1);
}
-#endif /* HAVE_LIBIAF && !BROKEN_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;
do_rc_files(s, shell);
/* restore SIGPIPE for child */
- signal(SIGPIPE, SIG_DFL);
+ 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);
struct stat st;
u_int len;
int success = 0;
- char *cmd, *subsys = packet_get_string(&len);
+ char *prog, *cmd, *subsys = packet_get_string(&len);
u_int i;
packet_check_eom();
for (i = 0; i < options.num_subsystems; i++) {
if (strcmp(subsys, options.subsystem_name[i]) == 0) {
- cmd = options.subsystem_command[i];
- if (stat(cmd, &st) < 0) {
- error("subsystem: cannot stat %s: %s", cmd,
+ prog = options.subsystem_command[i];
+ cmd = options.subsystem_args[i];
+ 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;
} else if (strcmp(rtype, "exec") == 0) {
success = session_exec_req(s);
} else if (strcmp(rtype, "pty-req") == 0) {
- success = session_pty_req(s);
+ success = session_pty_req(s);
} else if (strcmp(rtype, "x11-req") == 0) {
success = session_x11_req(s);
} else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
debug3("session_close_single_x11: channel %d", id);
channel_cancel_cleanup(id);
- if ((s = session_by_x11_channel(id)) == NULL)
+ if ((s = session_by_x11_channel(id)) == NULL)
fatal("session_close_single_x11: no x11 channel %d", id);
for (i = 0; s->x11_chanids[i] != -1; i++) {
debug("session_close_single_x11: session %d: "
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 */
if (s->auth_proto)
xfree(s->auth_proto);
s->used = 0;
- for (i = 0; i < s->num_env; i++) {
- xfree(s->env[i].name);
- xfree(s->env[i].val);
- }
- if (s->env != NULL)
+ if (s->env != NULL) {
+ for (i = 0; i < s->num_env; i++) {
+ xfree(s->env[i].name);
+ xfree(s->env[i].val);
+ }
xfree(s->env);
+ }
session_proctitle(s);
}
if (authctxt == NULL)
return;
+
+#ifdef USE_PAM
+ if (options.use_pam) {
+ sshpam_cleanup();
+ sshpam_thread_cleanup();
+ }
+#endif
+
+ if (!authctxt->authenticated)
+ return;
+
#ifdef KRB5
if (options.kerberos_ticket_cleanup &&
authctxt->krb5_ctx)
ssh_gssapi_cleanup_creds();
#endif
-#ifdef USE_PAM
- if (options.use_pam) {
- sshpam_cleanup();
- sshpam_thread_cleanup();
- }
-#endif
-
/* remove agent socket */
auth_sock_cleanup_proc(authctxt->pw);
andersk / openssh.git / blobdiff