This release fixes a number of security bugs and has minor new features and bug fixes. Security fixes, from the release notes (https://www.openssh.com/txt/release-9.3): This release contains fixes for a security problem and a memory safety problem. The memory safety problem is not believed to be exploitable, but we report most network-reachable memory faults as security bugs. * ssh-add(1): when adding smartcard keys to ssh-agent(1) with the per-hop destination constraints (ssh-add -h ...) added in OpenSSH 8.9, a logic error prevented the constraints from being communicated to the agent. This resulted in the keys being added without constraints. The common cases of non-smartcard keys and keys without destination constraints are unaffected. This problem was reported by Luci Stanescu. * ssh(1): Portable OpenSSH provides an implementation of the getrrsetbyname(3) function if the standard library does not provide it, for use by the VerifyHostKeyDNS feature. A specifically crafted DNS response could cause this function to perform an out-of-bounds read of adjacent stack data, but this condition does not appear to be exploitable beyond denial-of- service to the ssh(1) client. The getrrsetbyname(3) replacement is only included if the system's standard library lacks this function and portable OpenSSH was not compiled with the ldns library (--with-ldns). getrrsetbyname(3) is only invoked if using VerifyHostKeyDNS to fetch SSHFP records. This problem was found by the Coverity static analyzer. Sponsored by: The FreeBSD Foundation
2744 lines
68 KiB
C
2744 lines
68 KiB
C
/* $OpenBSD: session.c,v 1.335 2023/03/07 06:09:14 dtucker Exp $ */
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/*
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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*
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* As far as I am concerned, the code I have written for this software
|
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* can be used freely for any purpose. Any derived versions of this
|
|
* software must be clearly marked as such, and if the derived work is
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* incompatible with the protocol description in the RFC file, it must be
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* called by a name other than "ssh" or "Secure Shell".
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*
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* SSH2 support by Markus Friedl.
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* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "includes.h"
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#include <sys/types.h>
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#ifdef HAVE_SYS_STAT_H
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# include <sys/stat.h>
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#endif
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <sys/wait.h>
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#include <arpa/inet.h>
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|
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <grp.h>
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#include <netdb.h>
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#ifdef HAVE_PATHS_H
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#include <paths.h>
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#endif
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#include <pwd.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdarg.h>
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#include <unistd.h>
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#include <limits.h>
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#include "openbsd-compat/sys-queue.h"
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#include "xmalloc.h"
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#include "ssh.h"
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#include "ssh2.h"
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#include "sshpty.h"
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#include "packet.h"
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#include "sshbuf.h"
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#include "ssherr.h"
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#include "match.h"
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#include "uidswap.h"
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#include "channels.h"
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#include "sshkey.h"
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#include "cipher.h"
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#ifdef GSSAPI
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#include "ssh-gss.h"
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#endif
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#include "hostfile.h"
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#include "auth.h"
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#include "auth-options.h"
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#include "authfd.h"
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#include "pathnames.h"
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#include "log.h"
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#include "misc.h"
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#include "servconf.h"
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#include "sshlogin.h"
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#include "serverloop.h"
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#include "canohost.h"
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#include "session.h"
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#include "kex.h"
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#include "monitor_wrap.h"
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#include "sftp.h"
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#include "atomicio.h"
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|
|
|
#if defined(KRB5) && defined(USE_AFS)
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|
#include <kafs.h>
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|
#endif
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|
#ifdef WITH_SELINUX
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|
#include <selinux/selinux.h>
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|
#endif
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|
|
|
#define IS_INTERNAL_SFTP(c) \
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(!strncmp(c, INTERNAL_SFTP_NAME, sizeof(INTERNAL_SFTP_NAME) - 1) && \
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(c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\0' || \
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c[sizeof(INTERNAL_SFTP_NAME) - 1] == ' ' || \
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c[sizeof(INTERNAL_SFTP_NAME) - 1] == '\t'))
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/* func */
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|
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Session *session_new(void);
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void session_set_fds(struct ssh *, Session *, int, int, int, int, int);
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void session_pty_cleanup(Session *);
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void session_proctitle(Session *);
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int session_setup_x11fwd(struct ssh *, Session *);
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int do_exec_pty(struct ssh *, Session *, const char *);
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int do_exec_no_pty(struct ssh *, Session *, const char *);
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int do_exec(struct ssh *, Session *, const char *);
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void do_login(struct ssh *, Session *, const char *);
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void do_child(struct ssh *, Session *, const char *);
|
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void do_motd(void);
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int check_quietlogin(Session *, const char *);
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|
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static void do_authenticated2(struct ssh *, Authctxt *);
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|
|
static int session_pty_req(struct ssh *, Session *);
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|
|
/* import */
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|
extern ServerOptions options;
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extern char *__progname;
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|
extern int debug_flag;
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extern u_int utmp_len;
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extern int startup_pipe;
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extern void destroy_sensitive_data(void);
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extern struct sshbuf *loginmsg;
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extern struct sshauthopt *auth_opts;
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extern char *tun_fwd_ifnames; /* serverloop.c */
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/* original command from peer. */
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const char *original_command = NULL;
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/* data */
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static int sessions_first_unused = -1;
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static int sessions_nalloc = 0;
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static Session *sessions = NULL;
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|
#define SUBSYSTEM_NONE 0
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#define SUBSYSTEM_EXT 1
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#define SUBSYSTEM_INT_SFTP 2
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#define SUBSYSTEM_INT_SFTP_ERROR 3
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#ifdef HAVE_LOGIN_CAP
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login_cap_t *lc;
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#endif
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static int is_child = 0;
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static int in_chroot = 0;
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/* File containing userauth info, if ExposeAuthInfo set */
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static char *auth_info_file = NULL;
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/* Name and directory of socket for authentication agent forwarding. */
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static char *auth_sock_name = NULL;
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static char *auth_sock_dir = NULL;
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|
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/* removes the agent forwarding socket */
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|
|
|
static void
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auth_sock_cleanup_proc(struct passwd *pw)
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|
{
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if (auth_sock_name != NULL) {
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temporarily_use_uid(pw);
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unlink(auth_sock_name);
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rmdir(auth_sock_dir);
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auth_sock_name = NULL;
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restore_uid();
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|
}
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}
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|
static int
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auth_input_request_forwarding(struct ssh *ssh, struct passwd * pw)
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|
{
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Channel *nc;
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|
int sock = -1;
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|
|
if (auth_sock_name != NULL) {
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error("authentication forwarding requested twice.");
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return 0;
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}
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/* Temporarily drop privileged uid for mkdir/bind. */
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temporarily_use_uid(pw);
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/* Allocate a buffer for the socket name, and format the name. */
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auth_sock_dir = xstrdup("/tmp/ssh-XXXXXXXXXX");
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|
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/* Create private directory for socket */
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if (mkdtemp(auth_sock_dir) == NULL) {
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ssh_packet_send_debug(ssh, "Agent forwarding disabled: "
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"mkdtemp() failed: %.100s", strerror(errno));
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restore_uid();
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free(auth_sock_dir);
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auth_sock_dir = NULL;
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goto authsock_err;
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}
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xasprintf(&auth_sock_name, "%s/agent.%ld",
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auth_sock_dir, (long) getpid());
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/* Start a Unix listener on auth_sock_name. */
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sock = unix_listener(auth_sock_name, SSH_LISTEN_BACKLOG, 0);
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/* Restore the privileged uid. */
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restore_uid();
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/* Check for socket/bind/listen failure. */
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if (sock < 0)
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goto authsock_err;
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/* Allocate a channel for the authentication agent socket. */
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nc = channel_new(ssh, "auth-listener",
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SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
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CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
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0, "auth socket", 1);
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nc->path = xstrdup(auth_sock_name);
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return 1;
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authsock_err:
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free(auth_sock_name);
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if (auth_sock_dir != NULL) {
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temporarily_use_uid(pw);
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rmdir(auth_sock_dir);
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restore_uid();
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free(auth_sock_dir);
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}
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if (sock != -1)
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close(sock);
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auth_sock_name = NULL;
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auth_sock_dir = NULL;
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return 0;
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}
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static void
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display_loginmsg(void)
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{
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int r;
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if (sshbuf_len(loginmsg) == 0)
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return;
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if ((r = sshbuf_put_u8(loginmsg, 0)) != 0)
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fatal_fr(r, "sshbuf_put_u8");
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printf("%s", (char *)sshbuf_ptr(loginmsg));
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sshbuf_reset(loginmsg);
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}
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static void
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prepare_auth_info_file(struct passwd *pw, struct sshbuf *info)
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{
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int fd = -1, success = 0;
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if (!options.expose_userauth_info || info == NULL)
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return;
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temporarily_use_uid(pw);
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auth_info_file = xstrdup("/tmp/sshauth.XXXXXXXXXXXXXXX");
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if ((fd = mkstemp(auth_info_file)) == -1) {
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error_f("mkstemp: %s", strerror(errno));
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goto out;
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}
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if (atomicio(vwrite, fd, sshbuf_mutable_ptr(info),
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sshbuf_len(info)) != sshbuf_len(info)) {
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error_f("write: %s", strerror(errno));
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goto out;
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}
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if (close(fd) != 0) {
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error_f("close: %s", strerror(errno));
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goto out;
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}
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success = 1;
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out:
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if (!success) {
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if (fd != -1)
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close(fd);
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free(auth_info_file);
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auth_info_file = NULL;
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}
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restore_uid();
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}
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static void
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set_fwdpermit_from_authopts(struct ssh *ssh, const struct sshauthopt *opts)
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{
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char *tmp, *cp, *host;
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int port;
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size_t i;
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if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0) {
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channel_clear_permission(ssh, FORWARD_USER, FORWARD_LOCAL);
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for (i = 0; i < auth_opts->npermitopen; i++) {
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tmp = cp = xstrdup(auth_opts->permitopen[i]);
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/* This shouldn't fail as it has already been checked */
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if ((host = hpdelim2(&cp, NULL)) == NULL)
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fatal_f("internal error: hpdelim");
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host = cleanhostname(host);
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if (cp == NULL || (port = permitopen_port(cp)) < 0)
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fatal_f("internal error: permitopen port");
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channel_add_permission(ssh,
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FORWARD_USER, FORWARD_LOCAL, host, port);
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free(tmp);
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}
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}
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if ((options.allow_tcp_forwarding & FORWARD_REMOTE) != 0) {
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channel_clear_permission(ssh, FORWARD_USER, FORWARD_REMOTE);
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for (i = 0; i < auth_opts->npermitlisten; i++) {
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|
tmp = cp = xstrdup(auth_opts->permitlisten[i]);
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/* This shouldn't fail as it has already been checked */
|
|
if ((host = hpdelim(&cp)) == NULL)
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|
fatal_f("internal error: hpdelim");
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host = cleanhostname(host);
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|
if (cp == NULL || (port = permitopen_port(cp)) < 0)
|
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fatal_f("internal error: permitlisten port");
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channel_add_permission(ssh,
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FORWARD_USER, FORWARD_REMOTE, host, port);
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free(tmp);
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}
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}
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}
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|
void
|
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do_authenticated(struct ssh *ssh, Authctxt *authctxt)
|
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{
|
|
setproctitle("%s", authctxt->pw->pw_name);
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|
|
auth_log_authopts("active", auth_opts, 0);
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|
|
/* setup the channel layer */
|
|
/* XXX - streamlocal? */
|
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set_fwdpermit_from_authopts(ssh, auth_opts);
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|
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if (!auth_opts->permit_port_forwarding_flag ||
|
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options.disable_forwarding) {
|
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channel_disable_admin(ssh, FORWARD_LOCAL);
|
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channel_disable_admin(ssh, FORWARD_REMOTE);
|
|
} else {
|
|
if ((options.allow_tcp_forwarding & FORWARD_LOCAL) == 0)
|
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channel_disable_admin(ssh, FORWARD_LOCAL);
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else
|
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channel_permit_all(ssh, FORWARD_LOCAL);
|
|
if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0)
|
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channel_disable_admin(ssh, FORWARD_REMOTE);
|
|
else
|
|
channel_permit_all(ssh, FORWARD_REMOTE);
|
|
}
|
|
auth_debug_send(ssh);
|
|
|
|
prepare_auth_info_file(authctxt->pw, authctxt->session_info);
|
|
|
|
do_authenticated2(ssh, authctxt);
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|
|
do_cleanup(ssh, authctxt);
|
|
}
|
|
|
|
/* Check untrusted xauth strings for metacharacters */
|
|
static int
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|
xauth_valid_string(const char *s)
|
|
{
|
|
size_t i;
|
|
|
|
for (i = 0; s[i] != '\0'; i++) {
|
|
if (!isalnum((u_char)s[i]) &&
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s[i] != '.' && s[i] != ':' && s[i] != '/' &&
|
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s[i] != '-' && s[i] != '_')
|
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return 0;
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}
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return 1;
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}
|
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|
|
#define USE_PIPES 1
|
|
/*
|
|
* This is called to fork and execute a command when we have no tty. This
|
|
* will call do_child from the child, and server_loop from the parent after
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|
* setting up file descriptors and such.
|
|
*/
|
|
int
|
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do_exec_no_pty(struct ssh *ssh, Session *s, const char *command)
|
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{
|
|
pid_t pid;
|
|
#ifdef USE_PIPES
|
|
int pin[2], pout[2], perr[2];
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|
|
if (s == NULL)
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|
fatal("do_exec_no_pty: no session");
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|
|
|
/* Allocate pipes for communicating with the program. */
|
|
if (pipe(pin) == -1) {
|
|
error_f("pipe in: %.100s", strerror(errno));
|
|
return -1;
|
|
}
|
|
if (pipe(pout) == -1) {
|
|
error_f("pipe out: %.100s", strerror(errno));
|
|
close(pin[0]);
|
|
close(pin[1]);
|
|
return -1;
|
|
}
|
|
if (pipe(perr) == -1) {
|
|
error_f("pipe err: %.100s", strerror(errno));
|
|
close(pin[0]);
|
|
close(pin[1]);
|
|
close(pout[0]);
|
|
close(pout[1]);
|
|
return -1;
|
|
}
|
|
#else
|
|
int inout[2], err[2];
|
|
|
|
if (s == NULL)
|
|
fatal("do_exec_no_pty: no session");
|
|
|
|
/* Uses socket pairs to communicate with the program. */
|
|
if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) == -1) {
|
|
error_f("socketpair #1: %.100s", strerror(errno));
|
|
return -1;
|
|
}
|
|
if (socketpair(AF_UNIX, SOCK_STREAM, 0, err) == -1) {
|
|
error_f("socketpair #2: %.100s", strerror(errno));
|
|
close(inout[0]);
|
|
close(inout[1]);
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
session_proctitle(s);
|
|
|
|
/* Fork the child. */
|
|
switch ((pid = fork())) {
|
|
case -1:
|
|
error_f("fork: %.100s", strerror(errno));
|
|
#ifdef USE_PIPES
|
|
close(pin[0]);
|
|
close(pin[1]);
|
|
close(pout[0]);
|
|
close(pout[1]);
|
|
close(perr[0]);
|
|
close(perr[1]);
|
|
#else
|
|
close(inout[0]);
|
|
close(inout[1]);
|
|
close(err[0]);
|
|
close(err[1]);
|
|
#endif
|
|
return -1;
|
|
case 0:
|
|
is_child = 1;
|
|
|
|
/*
|
|
* Create a new session and process group since the 4.4BSD
|
|
* setlogin() affects the entire process group.
|
|
*/
|
|
if (setsid() == -1)
|
|
error("setsid failed: %.100s", strerror(errno));
|
|
|
|
#ifdef USE_PIPES
|
|
/*
|
|
* Redirect stdin. We close the parent side of the socket
|
|
* pair, and make the child side the standard input.
|
|
*/
|
|
close(pin[1]);
|
|
if (dup2(pin[0], 0) == -1)
|
|
perror("dup2 stdin");
|
|
close(pin[0]);
|
|
|
|
/* Redirect stdout. */
|
|
close(pout[0]);
|
|
if (dup2(pout[1], 1) == -1)
|
|
perror("dup2 stdout");
|
|
close(pout[1]);
|
|
|
|
/* Redirect stderr. */
|
|
close(perr[0]);
|
|
if (dup2(perr[1], 2) == -1)
|
|
perror("dup2 stderr");
|
|
close(perr[1]);
|
|
#else
|
|
/*
|
|
* Redirect stdin, stdout, and stderr. Stdin and stdout will
|
|
* use the same socket, as some programs (particularly rdist)
|
|
* seem to depend on it.
|
|
*/
|
|
close(inout[1]);
|
|
close(err[1]);
|
|
if (dup2(inout[0], 0) == -1) /* stdin */
|
|
perror("dup2 stdin");
|
|
if (dup2(inout[0], 1) == -1) /* stdout (same as stdin) */
|
|
perror("dup2 stdout");
|
|
close(inout[0]);
|
|
if (dup2(err[0], 2) == -1) /* stderr */
|
|
perror("dup2 stderr");
|
|
close(err[0]);
|
|
#endif
|
|
|
|
/* Do processing for the child (exec command etc). */
|
|
do_child(ssh, s, command);
|
|
/* NOTREACHED */
|
|
default:
|
|
break;
|
|
}
|
|
|
|
#ifdef HAVE_CYGWIN
|
|
cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
|
|
#endif
|
|
|
|
s->pid = pid;
|
|
/* Set interactive/non-interactive mode. */
|
|
ssh_packet_set_interactive(ssh, s->display != NULL,
|
|
options.ip_qos_interactive, options.ip_qos_bulk);
|
|
|
|
/*
|
|
* Clear loginmsg, since it's the child's responsibility to display
|
|
* it to the user, otherwise multiple sessions may accumulate
|
|
* multiple copies of the login messages.
|
|
*/
|
|
sshbuf_reset(loginmsg);
|
|
|
|
#ifdef USE_PIPES
|
|
/* We are the parent. Close the child sides of the pipes. */
|
|
close(pin[0]);
|
|
close(pout[1]);
|
|
close(perr[1]);
|
|
|
|
session_set_fds(ssh, s, pin[1], pout[0], perr[0],
|
|
s->is_subsystem, 0);
|
|
#else
|
|
/* We are the parent. Close the child sides of the socket pairs. */
|
|
close(inout[0]);
|
|
close(err[0]);
|
|
|
|
/*
|
|
* Enter the interactive session. Note: server_loop must be able to
|
|
* handle the case that fdin and fdout are the same.
|
|
*/
|
|
session_set_fds(ssh, s, inout[1], inout[1], err[1],
|
|
s->is_subsystem, 0);
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is called to fork and execute a command when we have a tty. This
|
|
* will call do_child from the child, and server_loop from the parent after
|
|
* setting up file descriptors, controlling tty, updating wtmp, utmp,
|
|
* lastlog, and other such operations.
|
|
*/
|
|
int
|
|
do_exec_pty(struct ssh *ssh, Session *s, const char *command)
|
|
{
|
|
int fdout, ptyfd, ttyfd, ptymaster;
|
|
pid_t pid;
|
|
|
|
if (s == NULL)
|
|
fatal("do_exec_pty: no session");
|
|
ptyfd = s->ptyfd;
|
|
ttyfd = s->ttyfd;
|
|
|
|
/*
|
|
* Create another descriptor of the pty master side for use as the
|
|
* standard input. We could use the original descriptor, but this
|
|
* simplifies code in server_loop. The descriptor is bidirectional.
|
|
* Do this before forking (and cleanup in the child) so as to
|
|
* detect and gracefully fail out-of-fd conditions.
|
|
*/
|
|
if ((fdout = dup(ptyfd)) == -1) {
|
|
error_f("dup #1: %s", strerror(errno));
|
|
close(ttyfd);
|
|
close(ptyfd);
|
|
return -1;
|
|
}
|
|
/* we keep a reference to the pty master */
|
|
if ((ptymaster = dup(ptyfd)) == -1) {
|
|
error_f("dup #2: %s", strerror(errno));
|
|
close(ttyfd);
|
|
close(ptyfd);
|
|
close(fdout);
|
|
return -1;
|
|
}
|
|
|
|
/* Fork the child. */
|
|
switch ((pid = fork())) {
|
|
case -1:
|
|
error_f("fork: %.100s", strerror(errno));
|
|
close(fdout);
|
|
close(ptymaster);
|
|
close(ttyfd);
|
|
close(ptyfd);
|
|
return -1;
|
|
case 0:
|
|
is_child = 1;
|
|
|
|
close(fdout);
|
|
close(ptymaster);
|
|
|
|
/* Close the master side of the pseudo tty. */
|
|
close(ptyfd);
|
|
|
|
/* Make the pseudo tty our controlling tty. */
|
|
pty_make_controlling_tty(&ttyfd, s->tty);
|
|
|
|
/* Redirect stdin/stdout/stderr from the pseudo tty. */
|
|
if (dup2(ttyfd, 0) == -1)
|
|
error("dup2 stdin: %s", strerror(errno));
|
|
if (dup2(ttyfd, 1) == -1)
|
|
error("dup2 stdout: %s", strerror(errno));
|
|
if (dup2(ttyfd, 2) == -1)
|
|
error("dup2 stderr: %s", strerror(errno));
|
|
|
|
/* Close the extra descriptor for the pseudo tty. */
|
|
close(ttyfd);
|
|
|
|
/* record login, etc. similar to login(1) */
|
|
#ifndef HAVE_OSF_SIA
|
|
do_login(ssh, s, command);
|
|
#endif
|
|
/*
|
|
* Do common processing for the child, such as execing
|
|
* the command.
|
|
*/
|
|
do_child(ssh, s, command);
|
|
/* NOTREACHED */
|
|
default:
|
|
break;
|
|
}
|
|
|
|
#ifdef HAVE_CYGWIN
|
|
cygwin_set_impersonation_token(INVALID_HANDLE_VALUE);
|
|
#endif
|
|
|
|
s->pid = pid;
|
|
|
|
/* Parent. Close the slave side of the pseudo tty. */
|
|
close(ttyfd);
|
|
|
|
/* Enter interactive session. */
|
|
s->ptymaster = ptymaster;
|
|
ssh_packet_set_interactive(ssh, 1,
|
|
options.ip_qos_interactive, options.ip_qos_bulk);
|
|
session_set_fds(ssh, s, ptyfd, fdout, -1, 1, 1);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* This is called to fork and execute a command. If another command is
|
|
* to be forced, execute that instead.
|
|
*/
|
|
int
|
|
do_exec(struct ssh *ssh, Session *s, const char *command)
|
|
{
|
|
int ret;
|
|
const char *forced = NULL, *tty = NULL;
|
|
char session_type[1024];
|
|
|
|
if (options.adm_forced_command) {
|
|
original_command = command;
|
|
command = options.adm_forced_command;
|
|
forced = "(config)";
|
|
} else if (auth_opts->force_command != NULL) {
|
|
original_command = command;
|
|
command = auth_opts->force_command;
|
|
forced = "(key-option)";
|
|
}
|
|
s->forced = 0;
|
|
if (forced != NULL) {
|
|
s->forced = 1;
|
|
if (IS_INTERNAL_SFTP(command)) {
|
|
s->is_subsystem = s->is_subsystem ?
|
|
SUBSYSTEM_INT_SFTP : SUBSYSTEM_INT_SFTP_ERROR;
|
|
} else if (s->is_subsystem)
|
|
s->is_subsystem = SUBSYSTEM_EXT;
|
|
snprintf(session_type, sizeof(session_type),
|
|
"forced-command %s '%.900s'", forced, command);
|
|
} else if (s->is_subsystem) {
|
|
snprintf(session_type, sizeof(session_type),
|
|
"subsystem '%.900s'", s->subsys);
|
|
} else if (command == NULL) {
|
|
snprintf(session_type, sizeof(session_type), "shell");
|
|
} else {
|
|
/* NB. we don't log unforced commands to preserve privacy */
|
|
snprintf(session_type, sizeof(session_type), "command");
|
|
}
|
|
|
|
if (s->ttyfd != -1) {
|
|
tty = s->tty;
|
|
if (strncmp(tty, "/dev/", 5) == 0)
|
|
tty += 5;
|
|
}
|
|
|
|
verbose("Starting session: %s%s%s for %s from %.200s port %d id %d",
|
|
session_type,
|
|
tty == NULL ? "" : " on ",
|
|
tty == NULL ? "" : tty,
|
|
s->pw->pw_name,
|
|
ssh_remote_ipaddr(ssh),
|
|
ssh_remote_port(ssh),
|
|
s->self);
|
|
|
|
#ifdef SSH_AUDIT_EVENTS
|
|
if (command != NULL)
|
|
PRIVSEP(audit_run_command(command));
|
|
else if (s->ttyfd == -1) {
|
|
char *shell = s->pw->pw_shell;
|
|
|
|
if (shell[0] == '\0') /* empty shell means /bin/sh */
|
|
shell =_PATH_BSHELL;
|
|
PRIVSEP(audit_run_command(shell));
|
|
}
|
|
#endif
|
|
if (s->ttyfd != -1)
|
|
ret = do_exec_pty(ssh, s, command);
|
|
else
|
|
ret = do_exec_no_pty(ssh, s, command);
|
|
|
|
original_command = NULL;
|
|
|
|
/*
|
|
* Clear loginmsg: it's the child's responsibility to display
|
|
* it to the user, otherwise multiple sessions may accumulate
|
|
* multiple copies of the login messages.
|
|
*/
|
|
sshbuf_reset(loginmsg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* administrative, login(1)-like work */
|
|
void
|
|
do_login(struct ssh *ssh, Session *s, const char *command)
|
|
{
|
|
socklen_t fromlen;
|
|
struct sockaddr_storage from;
|
|
struct passwd * pw = s->pw;
|
|
pid_t pid = getpid();
|
|
|
|
/*
|
|
* Get IP address of client. If the connection is not a socket, let
|
|
* the address be 0.0.0.0.
|
|
*/
|
|
memset(&from, 0, sizeof(from));
|
|
fromlen = sizeof(from);
|
|
if (ssh_packet_connection_is_on_socket(ssh)) {
|
|
if (getpeername(ssh_packet_get_connection_in(ssh),
|
|
(struct sockaddr *)&from, &fromlen) == -1) {
|
|
debug("getpeername: %.100s", strerror(errno));
|
|
cleanup_exit(255);
|
|
}
|
|
}
|
|
|
|
/* Record that there was a login on that tty from the remote host. */
|
|
if (!use_privsep)
|
|
record_login(pid, s->tty, pw->pw_name, pw->pw_uid,
|
|
session_get_remote_name_or_ip(ssh, utmp_len,
|
|
options.use_dns),
|
|
(struct sockaddr *)&from, fromlen);
|
|
|
|
#ifdef USE_PAM
|
|
/*
|
|
* If password change is needed, do it now.
|
|
* This needs to occur before the ~/.hushlogin check.
|
|
*/
|
|
if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) {
|
|
display_loginmsg();
|
|
do_pam_chauthtok();
|
|
s->authctxt->force_pwchange = 0;
|
|
/* XXX - signal [net] parent to enable forwardings */
|
|
}
|
|
#endif
|
|
|
|
if (check_quietlogin(s, command))
|
|
return;
|
|
|
|
display_loginmsg();
|
|
|
|
do_motd();
|
|
}
|
|
|
|
/*
|
|
* Display the message of the day.
|
|
*/
|
|
void
|
|
do_motd(void)
|
|
{
|
|
FILE *f;
|
|
char buf[256];
|
|
|
|
if (options.print_motd) {
|
|
#ifdef HAVE_LOGIN_CAP
|
|
f = fopen(login_getcapstr(lc, "welcome", "/etc/motd",
|
|
"/etc/motd"), "r");
|
|
#else
|
|
f = fopen("/etc/motd", "r");
|
|
#endif
|
|
if (f) {
|
|
while (fgets(buf, sizeof(buf), f))
|
|
fputs(buf, stdout);
|
|
fclose(f);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Check for quiet login, either .hushlogin or command given.
|
|
*/
|
|
int
|
|
check_quietlogin(Session *s, const char *command)
|
|
{
|
|
char buf[256];
|
|
struct passwd *pw = s->pw;
|
|
struct stat st;
|
|
|
|
/* Return 1 if .hushlogin exists or a command given. */
|
|
if (command != NULL)
|
|
return 1;
|
|
snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir);
|
|
#ifdef HAVE_LOGIN_CAP
|
|
if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0)
|
|
return 1;
|
|
#else
|
|
if (stat(buf, &st) >= 0)
|
|
return 1;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Reads environment variables from the given file and adds/overrides them
|
|
* into the environment. If the file does not exist, this does nothing.
|
|
* Otherwise, it must consist of empty lines, comments (line starts with '#')
|
|
* and assignments of the form name=value. No other forms are allowed.
|
|
* If allowlist is not NULL, then it is interpreted as a pattern list and
|
|
* only variable names that match it will be accepted.
|
|
*/
|
|
static void
|
|
read_environment_file(char ***env, u_int *envsize,
|
|
const char *filename, const char *allowlist)
|
|
{
|
|
FILE *f;
|
|
char *line = NULL, *cp, *value;
|
|
size_t linesize = 0;
|
|
u_int lineno = 0;
|
|
|
|
f = fopen(filename, "r");
|
|
if (!f)
|
|
return;
|
|
|
|
while (getline(&line, &linesize, f) != -1) {
|
|
if (++lineno > 1000)
|
|
fatal("Too many lines in environment file %s", filename);
|
|
for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
|
|
;
|
|
if (!*cp || *cp == '#' || *cp == '\n')
|
|
continue;
|
|
|
|
cp[strcspn(cp, "\n")] = '\0';
|
|
|
|
value = strchr(cp, '=');
|
|
if (value == NULL) {
|
|
fprintf(stderr, "Bad line %u in %.100s\n", lineno,
|
|
filename);
|
|
continue;
|
|
}
|
|
/*
|
|
* Replace the equals sign by nul, and advance value to
|
|
* the value string.
|
|
*/
|
|
*value = '\0';
|
|
value++;
|
|
if (allowlist != NULL &&
|
|
match_pattern_list(cp, allowlist, 0) != 1)
|
|
continue;
|
|
child_set_env(env, envsize, cp, value);
|
|
}
|
|
free(line);
|
|
fclose(f);
|
|
}
|
|
|
|
#ifdef HAVE_ETC_DEFAULT_LOGIN
|
|
/*
|
|
* Return named variable from specified environment, or NULL if not present.
|
|
*/
|
|
static char *
|
|
child_get_env(char **env, const char *name)
|
|
{
|
|
int i;
|
|
size_t len;
|
|
|
|
len = strlen(name);
|
|
for (i=0; env[i] != NULL; i++)
|
|
if (strncmp(name, env[i], len) == 0 && env[i][len] == '=')
|
|
return(env[i] + len + 1);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Read /etc/default/login.
|
|
* We pick up the PATH (or SUPATH for root) and UMASK.
|
|
*/
|
|
static void
|
|
read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
|
|
{
|
|
char **tmpenv = NULL, *var;
|
|
u_int i, tmpenvsize = 0;
|
|
u_long mask;
|
|
|
|
/*
|
|
* We don't want to copy the whole file to the child's environment,
|
|
* so we use a temporary environment and copy the variables we're
|
|
* interested in.
|
|
*/
|
|
read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login",
|
|
options.permit_user_env_allowlist);
|
|
|
|
if (tmpenv == NULL)
|
|
return;
|
|
|
|
if (uid == 0)
|
|
var = child_get_env(tmpenv, "SUPATH");
|
|
else
|
|
var = child_get_env(tmpenv, "PATH");
|
|
if (var != NULL)
|
|
child_set_env(env, envsize, "PATH", var);
|
|
|
|
if ((var = child_get_env(tmpenv, "UMASK")) != NULL)
|
|
if (sscanf(var, "%5lo", &mask) == 1)
|
|
umask((mode_t)mask);
|
|
|
|
for (i = 0; tmpenv[i] != NULL; i++)
|
|
free(tmpenv[i]);
|
|
free(tmpenv);
|
|
}
|
|
#endif /* HAVE_ETC_DEFAULT_LOGIN */
|
|
|
|
#if defined(USE_PAM) || defined(HAVE_CYGWIN)
|
|
static void
|
|
copy_environment_denylist(char **source, char ***env, u_int *envsize,
|
|
const char *denylist)
|
|
{
|
|
char *var_name, *var_val;
|
|
int i;
|
|
|
|
if (source == NULL)
|
|
return;
|
|
|
|
for(i = 0; source[i] != NULL; i++) {
|
|
var_name = xstrdup(source[i]);
|
|
if ((var_val = strstr(var_name, "=")) == NULL) {
|
|
free(var_name);
|
|
continue;
|
|
}
|
|
*var_val++ = '\0';
|
|
|
|
if (denylist == NULL ||
|
|
match_pattern_list(var_name, denylist, 0) != 1) {
|
|
debug3("Copy environment: %s=%s", var_name, var_val);
|
|
child_set_env(env, envsize, var_name, var_val);
|
|
}
|
|
|
|
free(var_name);
|
|
}
|
|
}
|
|
#endif /* defined(USE_PAM) || defined(HAVE_CYGWIN) */
|
|
|
|
#ifdef HAVE_CYGWIN
|
|
static void
|
|
copy_environment(char **source, char ***env, u_int *envsize)
|
|
{
|
|
copy_environment_denylist(source, env, envsize, NULL);
|
|
}
|
|
#endif
|
|
|
|
static char **
|
|
do_setup_env(struct ssh *ssh, Session *s, const char *shell)
|
|
{
|
|
char buf[256];
|
|
size_t n;
|
|
u_int i, envsize;
|
|
char *ocp, *cp, *value, **env, *laddr;
|
|
struct passwd *pw = s->pw;
|
|
#if !defined (HAVE_LOGIN_CAP) && !defined (HAVE_CYGWIN)
|
|
char *path = NULL;
|
|
#else
|
|
extern char **environ;
|
|
char **senv, **var, *val;
|
|
#endif
|
|
|
|
/* Initialize the environment. */
|
|
envsize = 100;
|
|
env = xcalloc(envsize, sizeof(char *));
|
|
env[0] = NULL;
|
|
|
|
#ifdef HAVE_CYGWIN
|
|
/*
|
|
* The Windows environment contains some setting which are
|
|
* important for a running system. They must not be dropped.
|
|
*/
|
|
{
|
|
char **p;
|
|
|
|
p = fetch_windows_environment();
|
|
copy_environment(p, &env, &envsize);
|
|
free_windows_environment(p);
|
|
}
|
|
#endif
|
|
|
|
if (getenv("TZ"))
|
|
child_set_env(&env, &envsize, "TZ", getenv("TZ"));
|
|
|
|
#ifdef GSSAPI
|
|
/* Allow any GSSAPI methods that we've used to alter
|
|
* the child's environment as they see fit
|
|
*/
|
|
ssh_gssapi_do_child(&env, &envsize);
|
|
#endif
|
|
|
|
/* Set basic environment. */
|
|
for (i = 0; i < s->num_env; i++)
|
|
child_set_env(&env, &envsize, s->env[i].name, s->env[i].val);
|
|
|
|
child_set_env(&env, &envsize, "USER", pw->pw_name);
|
|
child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
|
|
#ifdef _AIX
|
|
child_set_env(&env, &envsize, "LOGIN", pw->pw_name);
|
|
#endif
|
|
child_set_env(&env, &envsize, "HOME", pw->pw_dir);
|
|
snprintf(buf, sizeof buf, "%.200s/%.50s", _PATH_MAILDIR, pw->pw_name);
|
|
child_set_env(&env, &envsize, "MAIL", buf);
|
|
#ifdef HAVE_LOGIN_CAP
|
|
child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
|
|
child_set_env(&env, &envsize, "TERM", "su");
|
|
/*
|
|
* Temporarily swap out our real environment with an empty one,
|
|
* let setusercontext() apply any environment variables defined
|
|
* for the user's login class, copy those variables to the child,
|
|
* free the temporary environment, and restore the original.
|
|
*/
|
|
senv = environ;
|
|
environ = xmalloc(sizeof(*environ));
|
|
*environ = NULL;
|
|
(void)setusercontext(lc, pw, pw->pw_uid, LOGIN_SETENV|LOGIN_SETPATH);
|
|
for (var = environ; *var != NULL; ++var) {
|
|
if ((val = strchr(*var, '=')) != NULL) {
|
|
*val++ = '\0';
|
|
child_set_env(&env, &envsize, *var, val);
|
|
}
|
|
free(*var);
|
|
}
|
|
free(environ);
|
|
environ = senv;
|
|
#else /* HAVE_LOGIN_CAP */
|
|
# ifndef HAVE_CYGWIN
|
|
/*
|
|
* There's no standard path on Windows. The path contains
|
|
* important components pointing to the system directories,
|
|
* needed for loading shared libraries. So the path better
|
|
* remains intact here.
|
|
*/
|
|
# ifdef HAVE_ETC_DEFAULT_LOGIN
|
|
read_etc_default_login(&env, &envsize, pw->pw_uid);
|
|
path = child_get_env(env, "PATH");
|
|
# endif /* HAVE_ETC_DEFAULT_LOGIN */
|
|
if (path == NULL || *path == '\0') {
|
|
child_set_env(&env, &envsize, "PATH",
|
|
s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH);
|
|
}
|
|
# endif /* HAVE_CYGWIN */
|
|
#endif /* HAVE_LOGIN_CAP */
|
|
|
|
/* Normal systems set SHELL by default. */
|
|
child_set_env(&env, &envsize, "SHELL", shell);
|
|
|
|
if (s->term)
|
|
child_set_env(&env, &envsize, "TERM", s->term);
|
|
if (s->display)
|
|
child_set_env(&env, &envsize, "DISPLAY", s->display);
|
|
|
|
/*
|
|
* Since we clear KRB5CCNAME at startup, if it's set now then it
|
|
* must have been set by a native authentication method (eg AIX or
|
|
* SIA), so copy it to the child.
|
|
*/
|
|
{
|
|
char *cp;
|
|
|
|
if ((cp = getenv("KRB5CCNAME")) != NULL)
|
|
child_set_env(&env, &envsize, "KRB5CCNAME", cp);
|
|
}
|
|
|
|
#ifdef _AIX
|
|
{
|
|
char *cp;
|
|
|
|
if ((cp = getenv("AUTHSTATE")) != NULL)
|
|
child_set_env(&env, &envsize, "AUTHSTATE", cp);
|
|
read_environment_file(&env, &envsize, "/etc/environment",
|
|
options.permit_user_env_allowlist);
|
|
}
|
|
#endif
|
|
#ifdef KRB5
|
|
if (s->authctxt->krb5_ccname)
|
|
child_set_env(&env, &envsize, "KRB5CCNAME",
|
|
s->authctxt->krb5_ccname);
|
|
#endif
|
|
if (auth_sock_name != NULL)
|
|
child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
|
|
auth_sock_name);
|
|
|
|
|
|
/* Set custom environment options from pubkey authentication. */
|
|
if (options.permit_user_env) {
|
|
for (n = 0 ; n < auth_opts->nenv; n++) {
|
|
ocp = xstrdup(auth_opts->env[n]);
|
|
cp = strchr(ocp, '=');
|
|
if (cp != NULL) {
|
|
*cp = '\0';
|
|
/* Apply PermitUserEnvironment allowlist */
|
|
if (options.permit_user_env_allowlist == NULL ||
|
|
match_pattern_list(ocp,
|
|
options.permit_user_env_allowlist, 0) == 1)
|
|
child_set_env(&env, &envsize,
|
|
ocp, cp + 1);
|
|
}
|
|
free(ocp);
|
|
}
|
|
}
|
|
|
|
/* read $HOME/.ssh/environment. */
|
|
if (options.permit_user_env) {
|
|
snprintf(buf, sizeof buf, "%.200s/%s/environment",
|
|
pw->pw_dir, _PATH_SSH_USER_DIR);
|
|
read_environment_file(&env, &envsize, buf,
|
|
options.permit_user_env_allowlist);
|
|
}
|
|
|
|
#ifdef USE_PAM
|
|
/*
|
|
* Pull in any environment variables that may have
|
|
* been set by PAM.
|
|
*/
|
|
if (options.use_pam) {
|
|
char **p;
|
|
|
|
/*
|
|
* Don't allow PAM-internal env vars to leak
|
|
* back into the session environment.
|
|
*/
|
|
#define PAM_ENV_DENYLIST "SSH_AUTH_INFO*,SSH_CONNECTION*"
|
|
p = fetch_pam_child_environment();
|
|
copy_environment_denylist(p, &env, &envsize,
|
|
PAM_ENV_DENYLIST);
|
|
free_pam_environment(p);
|
|
|
|
p = fetch_pam_environment();
|
|
copy_environment_denylist(p, &env, &envsize,
|
|
PAM_ENV_DENYLIST);
|
|
free_pam_environment(p);
|
|
}
|
|
#endif /* USE_PAM */
|
|
|
|
/* Environment specified by admin */
|
|
for (i = 0; i < options.num_setenv; i++) {
|
|
cp = xstrdup(options.setenv[i]);
|
|
if ((value = strchr(cp, '=')) == NULL) {
|
|
/* shouldn't happen; vars are checked in servconf.c */
|
|
fatal("Invalid config SetEnv: %s", options.setenv[i]);
|
|
}
|
|
*value++ = '\0';
|
|
child_set_env(&env, &envsize, cp, value);
|
|
free(cp);
|
|
}
|
|
|
|
/* SSH_CLIENT deprecated */
|
|
snprintf(buf, sizeof buf, "%.50s %d %d",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
|
|
ssh_local_port(ssh));
|
|
child_set_env(&env, &envsize, "SSH_CLIENT", buf);
|
|
|
|
laddr = get_local_ipaddr(ssh_packet_get_connection_in(ssh));
|
|
snprintf(buf, sizeof buf, "%.50s %d %.50s %d",
|
|
ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
|
|
laddr, ssh_local_port(ssh));
|
|
free(laddr);
|
|
child_set_env(&env, &envsize, "SSH_CONNECTION", buf);
|
|
|
|
if (tun_fwd_ifnames != NULL)
|
|
child_set_env(&env, &envsize, "SSH_TUNNEL", tun_fwd_ifnames);
|
|
if (auth_info_file != NULL)
|
|
child_set_env(&env, &envsize, "SSH_USER_AUTH", auth_info_file);
|
|
if (s->ttyfd != -1)
|
|
child_set_env(&env, &envsize, "SSH_TTY", s->tty);
|
|
if (original_command)
|
|
child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND",
|
|
original_command);
|
|
|
|
if (debug_flag) {
|
|
/* dump the environment */
|
|
fprintf(stderr, "Environment:\n");
|
|
for (i = 0; env[i]; i++)
|
|
fprintf(stderr, " %.200s\n", env[i]);
|
|
}
|
|
return env;
|
|
}
|
|
|
|
/*
|
|
* Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found
|
|
* first in this order).
|
|
*/
|
|
static void
|
|
do_rc_files(struct ssh *ssh, Session *s, const char *shell)
|
|
{
|
|
FILE *f = NULL;
|
|
char *cmd = NULL, *user_rc = NULL;
|
|
int do_xauth;
|
|
struct stat st;
|
|
|
|
do_xauth =
|
|
s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL;
|
|
xasprintf(&user_rc, "%s/%s", s->pw->pw_dir, _PATH_SSH_USER_RC);
|
|
|
|
/* ignore _PATH_SSH_USER_RC for subsystems and admin forced commands */
|
|
if (!s->is_subsystem && options.adm_forced_command == NULL &&
|
|
auth_opts->permit_user_rc && options.permit_user_rc &&
|
|
stat(user_rc, &st) >= 0) {
|
|
if (xasprintf(&cmd, "%s -c '%s %s'", shell, _PATH_BSHELL,
|
|
user_rc) == -1)
|
|
fatal_f("xasprintf: %s", strerror(errno));
|
|
if (debug_flag)
|
|
fprintf(stderr, "Running %s\n", cmd);
|
|
f = popen(cmd, "w");
|
|
if (f) {
|
|
if (do_xauth)
|
|
fprintf(f, "%s %s\n", s->auth_proto,
|
|
s->auth_data);
|
|
pclose(f);
|
|
} else
|
|
fprintf(stderr, "Could not run %s\n",
|
|
user_rc);
|
|
} else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) {
|
|
if (debug_flag)
|
|
fprintf(stderr, "Running %s %s\n", _PATH_BSHELL,
|
|
_PATH_SSH_SYSTEM_RC);
|
|
f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w");
|
|
if (f) {
|
|
if (do_xauth)
|
|
fprintf(f, "%s %s\n", s->auth_proto,
|
|
s->auth_data);
|
|
pclose(f);
|
|
} else
|
|
fprintf(stderr, "Could not run %s\n",
|
|
_PATH_SSH_SYSTEM_RC);
|
|
} else if (do_xauth && options.xauth_location != NULL) {
|
|
/* Add authority data to .Xauthority if appropriate. */
|
|
if (debug_flag) {
|
|
fprintf(stderr,
|
|
"Running %.500s remove %.100s\n",
|
|
options.xauth_location, s->auth_display);
|
|
fprintf(stderr,
|
|
"%.500s add %.100s %.100s %.100s\n",
|
|
options.xauth_location, s->auth_display,
|
|
s->auth_proto, s->auth_data);
|
|
}
|
|
if (xasprintf(&cmd, "%s -q -", options.xauth_location) == -1)
|
|
fatal_f("xasprintf: %s", strerror(errno));
|
|
f = popen(cmd, "w");
|
|
if (f) {
|
|
fprintf(f, "remove %s\n",
|
|
s->auth_display);
|
|
fprintf(f, "add %s %s %s\n",
|
|
s->auth_display, s->auth_proto,
|
|
s->auth_data);
|
|
pclose(f);
|
|
} else {
|
|
fprintf(stderr, "Could not run %s\n",
|
|
cmd);
|
|
}
|
|
}
|
|
free(cmd);
|
|
free(user_rc);
|
|
}
|
|
|
|
static void
|
|
do_nologin(struct passwd *pw)
|
|
{
|
|
FILE *f = NULL;
|
|
const char *nl;
|
|
char buf[1024], *def_nl = _PATH_NOLOGIN;
|
|
struct stat sb;
|
|
|
|
#ifdef HAVE_LOGIN_CAP
|
|
if (login_getcapbool(lc, "ignorenologin", 0) || pw->pw_uid == 0)
|
|
return;
|
|
nl = login_getcapstr(lc, "nologin", def_nl, def_nl);
|
|
#else
|
|
if (pw->pw_uid == 0)
|
|
return;
|
|
nl = def_nl;
|
|
#endif
|
|
if (stat(nl, &sb) == -1)
|
|
return;
|
|
|
|
/* /etc/nologin exists. Print its contents if we can and exit. */
|
|
logit("User %.100s not allowed because %s exists", pw->pw_name, nl);
|
|
if ((f = fopen(nl, "r")) != NULL) {
|
|
while (fgets(buf, sizeof(buf), f))
|
|
fputs(buf, stderr);
|
|
fclose(f);
|
|
}
|
|
exit(254);
|
|
}
|
|
|
|
/*
|
|
* 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[PATH_MAX];
|
|
struct stat st;
|
|
|
|
if (!path_absolute(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_f("checking '%s'", component);
|
|
|
|
if (stat(component, &st) != 0)
|
|
fatal_f("stat(\"%s\"): %s",
|
|
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_f("chdir(/) after chroot: %s", strerror(errno));
|
|
verbose("Changed root directory to \"%s\"", path);
|
|
}
|
|
|
|
/* Set login name, uid, gid, and groups. */
|
|
void
|
|
do_setusercontext(struct passwd *pw)
|
|
{
|
|
char uidstr[32], *chroot_path, *tmp;
|
|
|
|
platform_setusercontext(pw);
|
|
|
|
if (platform_privileged_uidswap()) {
|
|
#ifdef HAVE_LOGIN_CAP
|
|
if (setusercontext(lc, pw, pw->pw_uid,
|
|
(LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH|LOGIN_SETUSER))) < 0) {
|
|
perror("unable to set user context");
|
|
exit(1);
|
|
}
|
|
#else
|
|
if (setlogin(pw->pw_name) < 0)
|
|
error("setlogin failed: %s", strerror(errno));
|
|
if (setgid(pw->pw_gid) < 0) {
|
|
perror("setgid");
|
|
exit(1);
|
|
}
|
|
/* Initialize the group list. */
|
|
if (initgroups(pw->pw_name, pw->pw_gid) < 0) {
|
|
perror("initgroups");
|
|
exit(1);
|
|
}
|
|
endgrent();
|
|
#endif
|
|
|
|
platform_setusercontext_post_groups(pw);
|
|
|
|
if (!in_chroot && options.chroot_directory != NULL &&
|
|
strcasecmp(options.chroot_directory, "none") != 0) {
|
|
tmp = tilde_expand_filename(options.chroot_directory,
|
|
pw->pw_uid);
|
|
snprintf(uidstr, sizeof(uidstr), "%llu",
|
|
(unsigned long long)pw->pw_uid);
|
|
chroot_path = percent_expand(tmp, "h", pw->pw_dir,
|
|
"u", pw->pw_name, "U", uidstr, (char *)NULL);
|
|
safely_chroot(chroot_path, pw->pw_uid);
|
|
free(tmp);
|
|
free(chroot_path);
|
|
/* Make sure we don't attempt to chroot again */
|
|
free(options.chroot_directory);
|
|
options.chroot_directory = NULL;
|
|
in_chroot = 1;
|
|
}
|
|
|
|
#ifdef HAVE_LOGIN_CAP
|
|
if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUSER) < 0) {
|
|
perror("unable to set user context (setuser)");
|
|
exit(1);
|
|
}
|
|
/*
|
|
* FreeBSD's setusercontext() will not apply the user's
|
|
* own umask setting unless running with the user's UID.
|
|
*/
|
|
(void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETUMASK);
|
|
#else
|
|
# ifdef USE_LIBIAF
|
|
/*
|
|
* In a chroot environment, the set_id() will always fail;
|
|
* typically because of the lack of necessary authentication
|
|
* services and runtime such as ./usr/lib/libiaf.so,
|
|
* ./usr/lib/libpam.so.1, and ./etc/passwd We skip it in the
|
|
* internal sftp chroot case. We'll lose auditing and ACLs but
|
|
* permanently_set_uid will take care of the rest.
|
|
*/
|
|
if (!in_chroot && set_id(pw->pw_name) != 0)
|
|
fatal("set_id(%s) Failed", pw->pw_name);
|
|
# endif /* USE_LIBIAF */
|
|
/* Permanently switch to the desired uid. */
|
|
permanently_set_uid(pw);
|
|
#endif
|
|
} else if (options.chroot_directory != NULL &&
|
|
strcasecmp(options.chroot_directory, "none") != 0) {
|
|
fatal("server lacks privileges to chroot to ChrootDirectory");
|
|
}
|
|
|
|
if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
|
|
fatal("Failed to set uids to %u.", (u_int) pw->pw_uid);
|
|
}
|
|
|
|
static void
|
|
do_pwchange(Session *s)
|
|
{
|
|
fflush(NULL);
|
|
fprintf(stderr, "WARNING: Your password has expired.\n");
|
|
if (s->ttyfd != -1) {
|
|
fprintf(stderr,
|
|
"You must change your password now and login again!\n");
|
|
#ifdef WITH_SELINUX
|
|
setexeccon(NULL);
|
|
#endif
|
|
#ifdef PASSWD_NEEDS_USERNAME
|
|
execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
|
|
(char *)NULL);
|
|
#else
|
|
execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
|
|
#endif
|
|
perror("passwd");
|
|
} else {
|
|
fprintf(stderr,
|
|
"Password change required but no TTY available.\n");
|
|
}
|
|
exit(1);
|
|
}
|
|
|
|
static void
|
|
child_close_fds(struct ssh *ssh)
|
|
{
|
|
extern int auth_sock;
|
|
|
|
if (auth_sock != -1) {
|
|
close(auth_sock);
|
|
auth_sock = -1;
|
|
}
|
|
|
|
if (ssh_packet_get_connection_in(ssh) ==
|
|
ssh_packet_get_connection_out(ssh))
|
|
close(ssh_packet_get_connection_in(ssh));
|
|
else {
|
|
close(ssh_packet_get_connection_in(ssh));
|
|
close(ssh_packet_get_connection_out(ssh));
|
|
}
|
|
/*
|
|
* Close all descriptors related to channels. They will still remain
|
|
* open in the parent.
|
|
*/
|
|
/* XXX better use close-on-exec? -markus */
|
|
channel_close_all(ssh);
|
|
|
|
/*
|
|
* Close any extra file descriptors. Note that there may still be
|
|
* descriptors left by system functions. They will be closed later.
|
|
*/
|
|
endpwent();
|
|
|
|
/* Stop directing logs to a high-numbered fd before we close it */
|
|
log_redirect_stderr_to(NULL);
|
|
|
|
/*
|
|
* Close any extra open file descriptors so that we don't have them
|
|
* hanging around in clients. Note that we want to do this after
|
|
* initgroups, because at least on Solaris 2.3 it leaves file
|
|
* descriptors open.
|
|
*/
|
|
closefrom(STDERR_FILENO + 1);
|
|
}
|
|
|
|
/*
|
|
* Performs common processing for the child, such as setting up the
|
|
* environment, closing extra file descriptors, setting the user and group
|
|
* ids, and executing the command or shell.
|
|
*/
|
|
#define ARGV_MAX 10
|
|
void
|
|
do_child(struct ssh *ssh, Session *s, const char *command)
|
|
{
|
|
extern char **environ;
|
|
char **env, *argv[ARGV_MAX], remote_id[512];
|
|
const char *shell, *shell0;
|
|
struct passwd *pw = s->pw;
|
|
int r = 0;
|
|
|
|
sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
|
|
|
|
/* remove hostkey from the child's memory */
|
|
destroy_sensitive_data();
|
|
ssh_packet_clear_keys(ssh);
|
|
|
|
/* Force a password change */
|
|
if (s->authctxt->force_pwchange) {
|
|
do_setusercontext(pw);
|
|
child_close_fds(ssh);
|
|
do_pwchange(s);
|
|
exit(1);
|
|
}
|
|
|
|
/*
|
|
* Login(1) does this as well, and it needs uid 0 for the "-h"
|
|
* switch, so we let login(1) to this for us.
|
|
*/
|
|
#ifdef HAVE_OSF_SIA
|
|
session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty);
|
|
if (!check_quietlogin(s, command))
|
|
do_motd();
|
|
#else /* HAVE_OSF_SIA */
|
|
/* When PAM is enabled we rely on it to do the nologin check */
|
|
if (!options.use_pam)
|
|
do_nologin(pw);
|
|
do_setusercontext(pw);
|
|
/*
|
|
* PAM session modules in do_setusercontext may have
|
|
* generated messages, so if this in an interactive
|
|
* login then display them too.
|
|
*/
|
|
if (!check_quietlogin(s, command))
|
|
display_loginmsg();
|
|
#endif /* HAVE_OSF_SIA */
|
|
|
|
#ifdef USE_PAM
|
|
if (options.use_pam && !is_pam_session_open()) {
|
|
debug3("PAM session not opened, exiting");
|
|
display_loginmsg();
|
|
exit(254);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Get the shell from the password data. An empty shell field is
|
|
* legal, and means /bin/sh.
|
|
*/
|
|
shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
|
|
|
|
/*
|
|
* Make sure $SHELL points to the shell from the password file,
|
|
* even if shell is overridden from login.conf
|
|
*/
|
|
env = do_setup_env(ssh, s, shell);
|
|
|
|
#ifdef HAVE_LOGIN_CAP
|
|
shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell);
|
|
#endif
|
|
|
|
/*
|
|
* Close the connection descriptors; note that this is the child, and
|
|
* the server will still have the socket open, and it is important
|
|
* that we do not shutdown it. Note that the descriptors cannot be
|
|
* closed before building the environment, as we call
|
|
* ssh_remote_ipaddr there.
|
|
*/
|
|
child_close_fds(ssh);
|
|
|
|
/*
|
|
* Must take new environment into use so that .ssh/rc,
|
|
* /etc/ssh/sshrc and xauth are run in the proper environment.
|
|
*/
|
|
environ = env;
|
|
|
|
#if defined(KRB5) && defined(USE_AFS)
|
|
/*
|
|
* At this point, we check to see if AFS is active and if we have
|
|
* a valid Kerberos 5 TGT. If so, it seems like a good idea to see
|
|
* if we can (and need to) extend the ticket into an AFS token. If
|
|
* we don't do this, we run into potential problems if the user's
|
|
* home directory is in AFS and it's not world-readable.
|
|
*/
|
|
|
|
if (options.kerberos_get_afs_token && k_hasafs() &&
|
|
(s->authctxt->krb5_ctx != NULL)) {
|
|
char cell[64];
|
|
|
|
debug("Getting AFS token");
|
|
|
|
k_setpag();
|
|
|
|
if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0)
|
|
krb5_afslog(s->authctxt->krb5_ctx,
|
|
s->authctxt->krb5_fwd_ccache, cell, NULL);
|
|
|
|
krb5_afslog_home(s->authctxt->krb5_ctx,
|
|
s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir);
|
|
}
|
|
#endif
|
|
|
|
/* Change current directory to the user's home directory. */
|
|
if (chdir(pw->pw_dir) == -1) {
|
|
/* Suppress missing homedir warning for chroot case */
|
|
#ifdef HAVE_LOGIN_CAP
|
|
r = login_getcapbool(lc, "requirehome", 0);
|
|
#endif
|
|
if (r || !in_chroot) {
|
|
fprintf(stderr, "Could not chdir to home "
|
|
"directory %s: %s\n", pw->pw_dir,
|
|
strerror(errno));
|
|
}
|
|
if (r)
|
|
exit(1);
|
|
}
|
|
|
|
closefrom(STDERR_FILENO + 1);
|
|
|
|
do_rc_files(ssh, s, shell);
|
|
|
|
/* restore SIGPIPE for child */
|
|
ssh_signal(SIGPIPE, SIG_DFL);
|
|
|
|
if (s->is_subsystem == SUBSYSTEM_INT_SFTP_ERROR) {
|
|
error("Connection from %s: refusing non-sftp session",
|
|
remote_id);
|
|
printf("This service allows sftp connections only.\n");
|
|
fflush(NULL);
|
|
exit(1);
|
|
} else if (s->is_subsystem == SUBSYSTEM_INT_SFTP) {
|
|
extern int optind, optreset;
|
|
int i;
|
|
char *p, *args;
|
|
|
|
setproctitle("%s@%s", s->pw->pw_name, INTERNAL_SFTP_NAME);
|
|
args = xstrdup(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];
|
|
#ifdef WITH_SELINUX
|
|
ssh_selinux_change_context("sftpd_t");
|
|
#endif
|
|
exit(sftp_server_main(i, argv, s->pw));
|
|
}
|
|
|
|
fflush(NULL);
|
|
|
|
/* Get the last component of the shell name. */
|
|
if ((shell0 = strrchr(shell, '/')) != NULL)
|
|
shell0++;
|
|
else
|
|
shell0 = shell;
|
|
|
|
/*
|
|
* If we have no command, execute the shell. In this case, the shell
|
|
* name to be passed in argv[0] is preceded by '-' to indicate that
|
|
* this is a login shell.
|
|
*/
|
|
if (!command) {
|
|
char argv0[256];
|
|
|
|
/* Start the shell. Set initial character to '-'. */
|
|
argv0[0] = '-';
|
|
|
|
if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1)
|
|
>= sizeof(argv0) - 1) {
|
|
errno = EINVAL;
|
|
perror(shell);
|
|
exit(1);
|
|
}
|
|
|
|
/* Execute the shell. */
|
|
argv[0] = argv0;
|
|
argv[1] = NULL;
|
|
execve(shell, argv, env);
|
|
|
|
/* Executing the shell failed. */
|
|
perror(shell);
|
|
exit(1);
|
|
}
|
|
/*
|
|
* Execute the command using the user's shell. This uses the -c
|
|
* option to execute the command.
|
|
*/
|
|
argv[0] = (char *) shell0;
|
|
argv[1] = "-c";
|
|
argv[2] = (char *) command;
|
|
argv[3] = NULL;
|
|
execve(shell, argv, env);
|
|
perror(shell);
|
|
exit(1);
|
|
}
|
|
|
|
void
|
|
session_unused(int id)
|
|
{
|
|
debug3_f("session id %d unused", id);
|
|
if (id >= options.max_sessions ||
|
|
id >= sessions_nalloc) {
|
|
fatal_f("insane session id %d (max %d nalloc %d)",
|
|
id, options.max_sessions, sessions_nalloc);
|
|
}
|
|
memset(&sessions[id], 0, sizeof(*sessions));
|
|
sessions[id].self = id;
|
|
sessions[id].used = 0;
|
|
sessions[id].chanid = -1;
|
|
sessions[id].ptyfd = -1;
|
|
sessions[id].ttyfd = -1;
|
|
sessions[id].ptymaster = -1;
|
|
sessions[id].x11_chanids = NULL;
|
|
sessions[id].next_unused = sessions_first_unused;
|
|
sessions_first_unused = id;
|
|
}
|
|
|
|
Session *
|
|
session_new(void)
|
|
{
|
|
Session *s, *tmp;
|
|
|
|
if (sessions_first_unused == -1) {
|
|
if (sessions_nalloc >= options.max_sessions)
|
|
return NULL;
|
|
debug2_f("allocate (allocated %d max %d)",
|
|
sessions_nalloc, options.max_sessions);
|
|
tmp = xrecallocarray(sessions, sessions_nalloc,
|
|
sessions_nalloc + 1, sizeof(*sessions));
|
|
if (tmp == NULL) {
|
|
error_f("cannot allocate %d sessions",
|
|
sessions_nalloc + 1);
|
|
return NULL;
|
|
}
|
|
sessions = tmp;
|
|
session_unused(sessions_nalloc++);
|
|
}
|
|
|
|
if (sessions_first_unused >= sessions_nalloc ||
|
|
sessions_first_unused < 0) {
|
|
fatal_f("insane first_unused %d max %d nalloc %d",
|
|
sessions_first_unused, options.max_sessions,
|
|
sessions_nalloc);
|
|
}
|
|
|
|
s = &sessions[sessions_first_unused];
|
|
if (s->used)
|
|
fatal_f("session %d already used", sessions_first_unused);
|
|
sessions_first_unused = s->next_unused;
|
|
s->used = 1;
|
|
s->next_unused = -1;
|
|
debug("session_new: session %d", s->self);
|
|
|
|
return s;
|
|
}
|
|
|
|
static void
|
|
session_dump(void)
|
|
{
|
|
int i;
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
|
|
debug("dump: used %d next_unused %d session %d "
|
|
"channel %d pid %ld",
|
|
s->used,
|
|
s->next_unused,
|
|
s->self,
|
|
s->chanid,
|
|
(long)s->pid);
|
|
}
|
|
}
|
|
|
|
int
|
|
session_open(Authctxt *authctxt, int chanid)
|
|
{
|
|
Session *s = session_new();
|
|
debug("session_open: channel %d", chanid);
|
|
if (s == NULL) {
|
|
error("no more sessions");
|
|
return 0;
|
|
}
|
|
s->authctxt = authctxt;
|
|
s->pw = authctxt->pw;
|
|
if (s->pw == NULL || !authctxt->valid)
|
|
fatal("no user for session %d", s->self);
|
|
debug("session_open: session %d: link with channel %d", s->self, chanid);
|
|
s->chanid = chanid;
|
|
return 1;
|
|
}
|
|
|
|
Session *
|
|
session_by_tty(char *tty)
|
|
{
|
|
int i;
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) {
|
|
debug("session_by_tty: session %d tty %s", i, tty);
|
|
return s;
|
|
}
|
|
}
|
|
debug("session_by_tty: unknown tty %.100s", tty);
|
|
session_dump();
|
|
return NULL;
|
|
}
|
|
|
|
static Session *
|
|
session_by_channel(int id)
|
|
{
|
|
int i;
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
if (s->used && s->chanid == id) {
|
|
debug("session_by_channel: session %d channel %d",
|
|
i, id);
|
|
return s;
|
|
}
|
|
}
|
|
debug("session_by_channel: unknown channel %d", id);
|
|
session_dump();
|
|
return NULL;
|
|
}
|
|
|
|
static Session *
|
|
session_by_x11_channel(int id)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
|
|
if (s->x11_chanids == NULL || !s->used)
|
|
continue;
|
|
for (j = 0; s->x11_chanids[j] != -1; j++) {
|
|
if (s->x11_chanids[j] == id) {
|
|
debug("session_by_x11_channel: session %d "
|
|
"channel %d", s->self, id);
|
|
return s;
|
|
}
|
|
}
|
|
}
|
|
debug("session_by_x11_channel: unknown channel %d", id);
|
|
session_dump();
|
|
return NULL;
|
|
}
|
|
|
|
static Session *
|
|
session_by_pid(pid_t pid)
|
|
{
|
|
int i;
|
|
debug("session_by_pid: pid %ld", (long)pid);
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
if (s->used && s->pid == pid)
|
|
return s;
|
|
}
|
|
error("session_by_pid: unknown pid %ld", (long)pid);
|
|
session_dump();
|
|
return NULL;
|
|
}
|
|
|
|
static int
|
|
session_window_change_req(struct ssh *ssh, Session *s)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_u32(ssh, &s->col)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->row)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->xpixel)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->ypixel)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
session_pty_req(struct ssh *ssh, Session *s)
|
|
{
|
|
int r;
|
|
|
|
if (!auth_opts->permit_pty_flag || !options.permit_tty) {
|
|
debug("Allocating a pty not permitted for this connection.");
|
|
return 0;
|
|
}
|
|
if (s->ttyfd != -1) {
|
|
ssh_packet_disconnect(ssh, "Protocol error: you already have a pty.");
|
|
return 0;
|
|
}
|
|
|
|
if ((r = sshpkt_get_cstring(ssh, &s->term, NULL)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->col)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->row)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->xpixel)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->ypixel)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
if (strcmp(s->term, "") == 0) {
|
|
free(s->term);
|
|
s->term = NULL;
|
|
}
|
|
|
|
/* Allocate a pty and open it. */
|
|
debug("Allocating pty.");
|
|
if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty,
|
|
sizeof(s->tty)))) {
|
|
free(s->term);
|
|
s->term = NULL;
|
|
s->ptyfd = -1;
|
|
s->ttyfd = -1;
|
|
error("session_pty_req: session %d alloc failed", s->self);
|
|
return 0;
|
|
}
|
|
debug("session_pty_req: session %d alloc %s", s->self, s->tty);
|
|
|
|
ssh_tty_parse_modes(ssh, s->ttyfd);
|
|
|
|
if ((r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
if (!use_privsep)
|
|
pty_setowner(s->pw, s->tty);
|
|
|
|
/* Set window size from the packet. */
|
|
pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel);
|
|
|
|
session_proctitle(s);
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
session_subsystem_req(struct ssh *ssh, Session *s)
|
|
{
|
|
struct stat st;
|
|
int r, success = 0;
|
|
char *prog, *cmd, *type;
|
|
u_int i;
|
|
|
|
if ((r = sshpkt_get_cstring(ssh, &s->subsys, NULL)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
debug2("subsystem request for %.100s by user %s", s->subsys,
|
|
s->pw->pw_name);
|
|
|
|
for (i = 0; i < options.num_subsystems; i++) {
|
|
if (strcmp(s->subsys, options.subsystem_name[i]) == 0) {
|
|
prog = options.subsystem_command[i];
|
|
cmd = options.subsystem_args[i];
|
|
if (strcmp(INTERNAL_SFTP_NAME, prog) == 0) {
|
|
s->is_subsystem = SUBSYSTEM_INT_SFTP;
|
|
debug("subsystem: %s", prog);
|
|
} else {
|
|
if (stat(prog, &st) == -1)
|
|
debug("subsystem: cannot stat %s: %s",
|
|
prog, strerror(errno));
|
|
s->is_subsystem = SUBSYSTEM_EXT;
|
|
debug("subsystem: exec() %s", cmd);
|
|
}
|
|
xasprintf(&type, "session:subsystem:%s",
|
|
options.subsystem_name[i]);
|
|
channel_set_xtype(ssh, s->chanid, type);
|
|
free(type);
|
|
success = do_exec(ssh, s, cmd) == 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!success)
|
|
logit("subsystem request for %.100s by user %s failed, "
|
|
"subsystem not found", s->subsys, s->pw->pw_name);
|
|
|
|
return success;
|
|
}
|
|
|
|
static int
|
|
session_x11_req(struct ssh *ssh, Session *s)
|
|
{
|
|
int r, success;
|
|
u_char single_connection = 0;
|
|
|
|
if (s->auth_proto != NULL || s->auth_data != NULL) {
|
|
error("session_x11_req: session %d: "
|
|
"x11 forwarding already active", s->self);
|
|
return 0;
|
|
}
|
|
if ((r = sshpkt_get_u8(ssh, &single_connection)) != 0 ||
|
|
(r = sshpkt_get_cstring(ssh, &s->auth_proto, NULL)) != 0 ||
|
|
(r = sshpkt_get_cstring(ssh, &s->auth_data, NULL)) != 0 ||
|
|
(r = sshpkt_get_u32(ssh, &s->screen)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
s->single_connection = single_connection;
|
|
|
|
if (xauth_valid_string(s->auth_proto) &&
|
|
xauth_valid_string(s->auth_data))
|
|
success = session_setup_x11fwd(ssh, s);
|
|
else {
|
|
success = 0;
|
|
error("Invalid X11 forwarding data");
|
|
}
|
|
if (!success) {
|
|
free(s->auth_proto);
|
|
free(s->auth_data);
|
|
s->auth_proto = NULL;
|
|
s->auth_data = NULL;
|
|
}
|
|
return success;
|
|
}
|
|
|
|
static int
|
|
session_shell_req(struct ssh *ssh, Session *s)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
channel_set_xtype(ssh, s->chanid, "session:shell");
|
|
|
|
return do_exec(ssh, s, NULL) == 0;
|
|
}
|
|
|
|
static int
|
|
session_exec_req(struct ssh *ssh, Session *s)
|
|
{
|
|
u_int success;
|
|
int r;
|
|
char *command = NULL;
|
|
|
|
if ((r = sshpkt_get_cstring(ssh, &command, NULL)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
channel_set_xtype(ssh, s->chanid, "session:command");
|
|
|
|
success = do_exec(ssh, s, command) == 0;
|
|
free(command);
|
|
return success;
|
|
}
|
|
|
|
static int
|
|
session_break_req(struct ssh *ssh, Session *s)
|
|
{
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_u32(ssh, NULL)) != 0 || /* ignore */
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
if (s->ptymaster == -1 || tcsendbreak(s->ptymaster, 0) == -1)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
session_env_req(struct ssh *ssh, Session *s)
|
|
{
|
|
char *name, *val;
|
|
u_int i;
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0 ||
|
|
(r = sshpkt_get_cstring(ssh, &val, NULL)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
|
|
/* Don't set too many environment variables */
|
|
if (s->num_env > 128) {
|
|
debug2("Ignoring env request %s: too many env vars", name);
|
|
goto fail;
|
|
}
|
|
|
|
for (i = 0; i < options.num_accept_env; i++) {
|
|
if (match_pattern(name, options.accept_env[i])) {
|
|
debug2("Setting env %d: %s=%s", s->num_env, name, val);
|
|
s->env = xrecallocarray(s->env, s->num_env,
|
|
s->num_env + 1, sizeof(*s->env));
|
|
s->env[s->num_env].name = name;
|
|
s->env[s->num_env].val = val;
|
|
s->num_env++;
|
|
return (1);
|
|
}
|
|
}
|
|
debug2("Ignoring env request %s: disallowed name", name);
|
|
|
|
fail:
|
|
free(name);
|
|
free(val);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Conversion of signals from ssh channel request names.
|
|
* Subset of signals from RFC 4254 section 6.10C, with SIGINFO as
|
|
* local extension.
|
|
*/
|
|
static int
|
|
name2sig(char *name)
|
|
{
|
|
#define SSH_SIG(x) if (strcmp(name, #x) == 0) return SIG ## x
|
|
SSH_SIG(HUP);
|
|
SSH_SIG(INT);
|
|
SSH_SIG(KILL);
|
|
SSH_SIG(QUIT);
|
|
SSH_SIG(TERM);
|
|
SSH_SIG(USR1);
|
|
SSH_SIG(USR2);
|
|
#undef SSH_SIG
|
|
#ifdef SIGINFO
|
|
if (strcmp(name, "INFO@openssh.com") == 0)
|
|
return SIGINFO;
|
|
#endif
|
|
return -1;
|
|
}
|
|
|
|
static int
|
|
session_signal_req(struct ssh *ssh, Session *s)
|
|
{
|
|
char *signame = NULL;
|
|
int r, sig, success = 0;
|
|
|
|
if ((r = sshpkt_get_cstring(ssh, &signame, NULL)) != 0 ||
|
|
(r = sshpkt_get_end(ssh)) != 0) {
|
|
error_fr(r, "parse");
|
|
goto out;
|
|
}
|
|
if ((sig = name2sig(signame)) == -1) {
|
|
error_f("unsupported signal \"%s\"", signame);
|
|
goto out;
|
|
}
|
|
if (s->pid <= 0) {
|
|
error_f("no pid for session %d", s->self);
|
|
goto out;
|
|
}
|
|
if (s->forced || s->is_subsystem) {
|
|
error_f("refusing to send signal %s to %s session",
|
|
signame, s->forced ? "forced-command" : "subsystem");
|
|
goto out;
|
|
}
|
|
if (!use_privsep || mm_is_monitor()) {
|
|
error_f("session signalling requires privilege separation");
|
|
goto out;
|
|
}
|
|
|
|
debug_f("signal %s, killpg(%ld, %d)", signame, (long)s->pid, sig);
|
|
temporarily_use_uid(s->pw);
|
|
r = killpg(s->pid, sig);
|
|
restore_uid();
|
|
if (r != 0) {
|
|
error_f("killpg(%ld, %d): %s", (long)s->pid,
|
|
sig, strerror(errno));
|
|
goto out;
|
|
}
|
|
|
|
/* success */
|
|
success = 1;
|
|
out:
|
|
free(signame);
|
|
return success;
|
|
}
|
|
|
|
static int
|
|
session_auth_agent_req(struct ssh *ssh, Session *s)
|
|
{
|
|
static int called = 0;
|
|
int r;
|
|
|
|
if ((r = sshpkt_get_end(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
|
|
if (!auth_opts->permit_agent_forwarding_flag ||
|
|
!options.allow_agent_forwarding) {
|
|
debug_f("agent forwarding disabled");
|
|
return 0;
|
|
}
|
|
if (called) {
|
|
return 0;
|
|
} else {
|
|
called = 1;
|
|
return auth_input_request_forwarding(ssh, s->pw);
|
|
}
|
|
}
|
|
|
|
int
|
|
session_input_channel_req(struct ssh *ssh, Channel *c, const char *rtype)
|
|
{
|
|
int success = 0;
|
|
Session *s;
|
|
|
|
if ((s = session_by_channel(c->self)) == NULL) {
|
|
logit_f("no session %d req %.100s", c->self, rtype);
|
|
return 0;
|
|
}
|
|
debug_f("session %d req %s", s->self, rtype);
|
|
|
|
/*
|
|
* a session is in LARVAL state until a shell, a command
|
|
* or a subsystem is executed
|
|
*/
|
|
if (c->type == SSH_CHANNEL_LARVAL) {
|
|
if (strcmp(rtype, "shell") == 0) {
|
|
success = session_shell_req(ssh, s);
|
|
} else if (strcmp(rtype, "exec") == 0) {
|
|
success = session_exec_req(ssh, s);
|
|
} else if (strcmp(rtype, "pty-req") == 0) {
|
|
success = session_pty_req(ssh, s);
|
|
} else if (strcmp(rtype, "x11-req") == 0) {
|
|
success = session_x11_req(ssh, s);
|
|
} else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) {
|
|
success = session_auth_agent_req(ssh, s);
|
|
} else if (strcmp(rtype, "subsystem") == 0) {
|
|
success = session_subsystem_req(ssh, s);
|
|
} else if (strcmp(rtype, "env") == 0) {
|
|
success = session_env_req(ssh, s);
|
|
}
|
|
}
|
|
if (strcmp(rtype, "window-change") == 0) {
|
|
success = session_window_change_req(ssh, s);
|
|
} else if (strcmp(rtype, "break") == 0) {
|
|
success = session_break_req(ssh, s);
|
|
} else if (strcmp(rtype, "signal") == 0) {
|
|
success = session_signal_req(ssh, s);
|
|
}
|
|
|
|
return success;
|
|
}
|
|
|
|
void
|
|
session_set_fds(struct ssh *ssh, Session *s,
|
|
int fdin, int fdout, int fderr, int ignore_fderr, int is_tty)
|
|
{
|
|
/*
|
|
* now that have a child and a pipe to the child,
|
|
* we can activate our channel and register the fd's
|
|
*/
|
|
if (s->chanid == -1)
|
|
fatal("no channel for session %d", s->self);
|
|
channel_set_fds(ssh, s->chanid,
|
|
fdout, fdin, fderr,
|
|
ignore_fderr ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ,
|
|
1, is_tty, CHAN_SES_WINDOW_DEFAULT);
|
|
}
|
|
|
|
/*
|
|
* Function to perform pty cleanup. Also called if we get aborted abnormally
|
|
* (e.g., due to a dropped connection).
|
|
*/
|
|
void
|
|
session_pty_cleanup2(Session *s)
|
|
{
|
|
if (s == NULL) {
|
|
error_f("no session");
|
|
return;
|
|
}
|
|
if (s->ttyfd == -1)
|
|
return;
|
|
|
|
debug_f("session %d release %s", s->self, s->tty);
|
|
|
|
/* Record that the user has logged out. */
|
|
if (s->pid != 0)
|
|
record_logout(s->pid, s->tty, s->pw->pw_name);
|
|
|
|
/* Release the pseudo-tty. */
|
|
if (getuid() == 0)
|
|
pty_release(s->tty);
|
|
|
|
/*
|
|
* Close the server side of the socket pairs. We must do this after
|
|
* the pty cleanup, so that another process doesn't get this pty
|
|
* while we're still cleaning up.
|
|
*/
|
|
if (s->ptymaster != -1 && close(s->ptymaster) == -1)
|
|
error("close(s->ptymaster/%d): %s",
|
|
s->ptymaster, strerror(errno));
|
|
|
|
/* unlink pty from session */
|
|
s->ttyfd = -1;
|
|
}
|
|
|
|
void
|
|
session_pty_cleanup(Session *s)
|
|
{
|
|
PRIVSEP(session_pty_cleanup2(s));
|
|
}
|
|
|
|
static char *
|
|
sig2name(int sig)
|
|
{
|
|
#define SSH_SIG(x) if (sig == SIG ## x) return #x
|
|
SSH_SIG(ABRT);
|
|
SSH_SIG(ALRM);
|
|
SSH_SIG(FPE);
|
|
SSH_SIG(HUP);
|
|
SSH_SIG(ILL);
|
|
SSH_SIG(INT);
|
|
SSH_SIG(KILL);
|
|
SSH_SIG(PIPE);
|
|
SSH_SIG(QUIT);
|
|
SSH_SIG(SEGV);
|
|
SSH_SIG(TERM);
|
|
SSH_SIG(USR1);
|
|
SSH_SIG(USR2);
|
|
#undef SSH_SIG
|
|
return "SIG@openssh.com";
|
|
}
|
|
|
|
static void
|
|
session_close_x11(struct ssh *ssh, int id)
|
|
{
|
|
Channel *c;
|
|
|
|
if ((c = channel_by_id(ssh, id)) == NULL) {
|
|
debug_f("x11 channel %d missing", id);
|
|
} else {
|
|
/* Detach X11 listener */
|
|
debug_f("detach x11 channel %d", id);
|
|
channel_cancel_cleanup(ssh, id);
|
|
if (c->ostate != CHAN_OUTPUT_CLOSED)
|
|
chan_mark_dead(ssh, c);
|
|
}
|
|
}
|
|
|
|
static void
|
|
session_close_single_x11(struct ssh *ssh, int id, int force, void *arg)
|
|
{
|
|
Session *s;
|
|
u_int i;
|
|
|
|
debug3_f("channel %d", id);
|
|
channel_cancel_cleanup(ssh, id);
|
|
if ((s = session_by_x11_channel(id)) == NULL)
|
|
fatal_f("no x11 channel %d", id);
|
|
for (i = 0; s->x11_chanids[i] != -1; i++) {
|
|
debug_f("session %d: closing channel %d",
|
|
s->self, s->x11_chanids[i]);
|
|
/*
|
|
* The channel "id" is already closing, but make sure we
|
|
* close all of its siblings.
|
|
*/
|
|
if (s->x11_chanids[i] != id)
|
|
session_close_x11(ssh, s->x11_chanids[i]);
|
|
}
|
|
free(s->x11_chanids);
|
|
s->x11_chanids = NULL;
|
|
free(s->display);
|
|
s->display = NULL;
|
|
free(s->auth_proto);
|
|
s->auth_proto = NULL;
|
|
free(s->auth_data);
|
|
s->auth_data = NULL;
|
|
free(s->auth_display);
|
|
s->auth_display = NULL;
|
|
}
|
|
|
|
static void
|
|
session_exit_message(struct ssh *ssh, Session *s, int status)
|
|
{
|
|
Channel *c;
|
|
int r;
|
|
|
|
if ((c = channel_lookup(ssh, s->chanid)) == NULL)
|
|
fatal_f("session %d: no channel %d", s->self, s->chanid);
|
|
debug_f("session %d channel %d pid %ld",
|
|
s->self, s->chanid, (long)s->pid);
|
|
|
|
if (WIFEXITED(status)) {
|
|
channel_request_start(ssh, s->chanid, "exit-status", 0);
|
|
if ((r = sshpkt_put_u32(ssh, WEXITSTATUS(status))) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: exit reply", __func__);
|
|
} else if (WIFSIGNALED(status)) {
|
|
channel_request_start(ssh, s->chanid, "exit-signal", 0);
|
|
#ifndef WCOREDUMP
|
|
# define WCOREDUMP(x) (0)
|
|
#endif
|
|
if ((r = sshpkt_put_cstring(ssh, sig2name(WTERMSIG(status)))) != 0 ||
|
|
(r = sshpkt_put_u8(ssh, WCOREDUMP(status)? 1 : 0)) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, "")) != 0 ||
|
|
(r = sshpkt_put_cstring(ssh, "")) != 0 ||
|
|
(r = sshpkt_send(ssh)) != 0)
|
|
sshpkt_fatal(ssh, r, "%s: exit reply", __func__);
|
|
} else {
|
|
/* Some weird exit cause. Just exit. */
|
|
ssh_packet_disconnect(ssh, "wait returned status %04x.", status);
|
|
}
|
|
|
|
/* disconnect channel */
|
|
debug_f("release channel %d", s->chanid);
|
|
|
|
/*
|
|
* Adjust cleanup callback attachment to send close messages when
|
|
* the channel gets EOF. The session will be then be closed
|
|
* by session_close_by_channel when the child sessions close their fds.
|
|
*/
|
|
channel_register_cleanup(ssh, c->self, session_close_by_channel, 1);
|
|
|
|
/*
|
|
* emulate a write failure with 'chan_write_failed', nobody will be
|
|
* interested in data we write.
|
|
* Note that we must not call 'chan_read_failed', since there could
|
|
* be some more data waiting in the pipe.
|
|
*/
|
|
if (c->ostate != CHAN_OUTPUT_CLOSED)
|
|
chan_write_failed(ssh, c);
|
|
}
|
|
|
|
void
|
|
session_close(struct ssh *ssh, Session *s)
|
|
{
|
|
u_int i;
|
|
|
|
verbose("Close session: user %s from %.200s port %d id %d",
|
|
s->pw->pw_name,
|
|
ssh_remote_ipaddr(ssh),
|
|
ssh_remote_port(ssh),
|
|
s->self);
|
|
|
|
if (s->ttyfd != -1)
|
|
session_pty_cleanup(s);
|
|
free(s->term);
|
|
free(s->display);
|
|
free(s->x11_chanids);
|
|
free(s->auth_display);
|
|
free(s->auth_data);
|
|
free(s->auth_proto);
|
|
free(s->subsys);
|
|
if (s->env != NULL) {
|
|
for (i = 0; i < s->num_env; i++) {
|
|
free(s->env[i].name);
|
|
free(s->env[i].val);
|
|
}
|
|
free(s->env);
|
|
}
|
|
session_proctitle(s);
|
|
session_unused(s->self);
|
|
}
|
|
|
|
void
|
|
session_close_by_pid(struct ssh *ssh, pid_t pid, int status)
|
|
{
|
|
Session *s = session_by_pid(pid);
|
|
if (s == NULL) {
|
|
debug_f("no session for pid %ld", (long)pid);
|
|
return;
|
|
}
|
|
if (s->chanid != -1)
|
|
session_exit_message(ssh, s, status);
|
|
if (s->ttyfd != -1)
|
|
session_pty_cleanup(s);
|
|
s->pid = 0;
|
|
}
|
|
|
|
/*
|
|
* this is called when a channel dies before
|
|
* the session 'child' itself dies
|
|
*/
|
|
void
|
|
session_close_by_channel(struct ssh *ssh, int id, int force, void *arg)
|
|
{
|
|
Session *s = session_by_channel(id);
|
|
u_int i;
|
|
|
|
if (s == NULL) {
|
|
debug_f("no session for id %d", id);
|
|
return;
|
|
}
|
|
debug_f("channel %d child %ld", id, (long)s->pid);
|
|
if (s->pid != 0) {
|
|
debug_f("channel %d: has child, ttyfd %d", id, s->ttyfd);
|
|
/*
|
|
* delay detach of session (unless this is a forced close),
|
|
* but release pty, since the fd's to the child are already
|
|
* closed
|
|
*/
|
|
if (s->ttyfd != -1)
|
|
session_pty_cleanup(s);
|
|
if (!force)
|
|
return;
|
|
}
|
|
/* detach by removing callback */
|
|
channel_cancel_cleanup(ssh, s->chanid);
|
|
|
|
/* Close any X11 listeners associated with this session */
|
|
if (s->x11_chanids != NULL) {
|
|
for (i = 0; s->x11_chanids[i] != -1; i++) {
|
|
session_close_x11(ssh, s->x11_chanids[i]);
|
|
s->x11_chanids[i] = -1;
|
|
}
|
|
}
|
|
|
|
s->chanid = -1;
|
|
session_close(ssh, s);
|
|
}
|
|
|
|
void
|
|
session_destroy_all(struct ssh *ssh, void (*closefunc)(Session *))
|
|
{
|
|
int i;
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
if (s->used) {
|
|
if (closefunc != NULL)
|
|
closefunc(s);
|
|
else
|
|
session_close(ssh, s);
|
|
}
|
|
}
|
|
}
|
|
|
|
static char *
|
|
session_tty_list(void)
|
|
{
|
|
static char buf[1024];
|
|
int i;
|
|
char *cp;
|
|
|
|
buf[0] = '\0';
|
|
for (i = 0; i < sessions_nalloc; i++) {
|
|
Session *s = &sessions[i];
|
|
if (s->used && s->ttyfd != -1) {
|
|
|
|
if (strncmp(s->tty, "/dev/", 5) != 0) {
|
|
cp = strrchr(s->tty, '/');
|
|
cp = (cp == NULL) ? s->tty : cp + 1;
|
|
} else
|
|
cp = s->tty + 5;
|
|
|
|
if (buf[0] != '\0')
|
|
strlcat(buf, ",", sizeof buf);
|
|
strlcat(buf, cp, sizeof buf);
|
|
}
|
|
}
|
|
if (buf[0] == '\0')
|
|
strlcpy(buf, "notty", sizeof buf);
|
|
return buf;
|
|
}
|
|
|
|
void
|
|
session_proctitle(Session *s)
|
|
{
|
|
if (s->pw == NULL)
|
|
error("no user for session %d", s->self);
|
|
else
|
|
setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
|
|
}
|
|
|
|
int
|
|
session_setup_x11fwd(struct ssh *ssh, Session *s)
|
|
{
|
|
struct stat st;
|
|
char display[512], auth_display[512];
|
|
char hostname[NI_MAXHOST];
|
|
u_int i;
|
|
|
|
if (!auth_opts->permit_x11_forwarding_flag) {
|
|
ssh_packet_send_debug(ssh, "X11 forwarding disabled by key options.");
|
|
return 0;
|
|
}
|
|
if (!options.x11_forwarding) {
|
|
debug("X11 forwarding disabled in server configuration file.");
|
|
return 0;
|
|
}
|
|
if (options.xauth_location == NULL ||
|
|
(stat(options.xauth_location, &st) == -1)) {
|
|
ssh_packet_send_debug(ssh, "No xauth program; cannot forward X11.");
|
|
return 0;
|
|
}
|
|
if (s->display != NULL) {
|
|
debug("X11 display already set.");
|
|
return 0;
|
|
}
|
|
if (x11_create_display_inet(ssh, options.x11_display_offset,
|
|
options.x11_use_localhost, s->single_connection,
|
|
&s->display_number, &s->x11_chanids) == -1) {
|
|
debug("x11_create_display_inet failed.");
|
|
return 0;
|
|
}
|
|
for (i = 0; s->x11_chanids[i] != -1; i++) {
|
|
channel_register_cleanup(ssh, s->x11_chanids[i],
|
|
session_close_single_x11, 0);
|
|
}
|
|
|
|
/* Set up a suitable value for the DISPLAY variable. */
|
|
if (gethostname(hostname, sizeof(hostname)) == -1)
|
|
fatal("gethostname: %.100s", strerror(errno));
|
|
/*
|
|
* auth_display must be used as the displayname when the
|
|
* authorization entry is added with xauth(1). This will be
|
|
* different than the DISPLAY string for localhost displays.
|
|
*/
|
|
if (options.x11_use_localhost) {
|
|
snprintf(display, sizeof display, "localhost:%u.%u",
|
|
s->display_number, s->screen);
|
|
snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
|
|
s->display_number, s->screen);
|
|
s->display = xstrdup(display);
|
|
s->auth_display = xstrdup(auth_display);
|
|
} else {
|
|
#ifdef IPADDR_IN_DISPLAY
|
|
struct hostent *he;
|
|
struct in_addr my_addr;
|
|
|
|
he = gethostbyname(hostname);
|
|
if (he == NULL) {
|
|
error("Can't get IP address for X11 DISPLAY.");
|
|
ssh_packet_send_debug(ssh, "Can't get IP address for X11 DISPLAY.");
|
|
return 0;
|
|
}
|
|
memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
|
|
snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
|
|
s->display_number, s->screen);
|
|
#else
|
|
snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
|
|
s->display_number, s->screen);
|
|
#endif
|
|
s->display = xstrdup(display);
|
|
s->auth_display = xstrdup(display);
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static void
|
|
do_authenticated2(struct ssh *ssh, Authctxt *authctxt)
|
|
{
|
|
server_loop2(ssh, authctxt);
|
|
}
|
|
|
|
void
|
|
do_cleanup(struct ssh *ssh, Authctxt *authctxt)
|
|
{
|
|
static int called = 0;
|
|
|
|
debug("do_cleanup");
|
|
|
|
/* no cleanup if we're in the child for login shell */
|
|
if (is_child)
|
|
return;
|
|
|
|
/* avoid double cleanup */
|
|
if (called)
|
|
return;
|
|
called = 1;
|
|
|
|
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)
|
|
krb5_cleanup_proc(authctxt);
|
|
#endif
|
|
|
|
#ifdef GSSAPI
|
|
if (options.gss_cleanup_creds)
|
|
ssh_gssapi_cleanup_creds();
|
|
#endif
|
|
|
|
/* remove agent socket */
|
|
auth_sock_cleanup_proc(authctxt->pw);
|
|
|
|
/* remove userauth info */
|
|
if (auth_info_file != NULL) {
|
|
temporarily_use_uid(authctxt->pw);
|
|
unlink(auth_info_file);
|
|
restore_uid();
|
|
free(auth_info_file);
|
|
auth_info_file = NULL;
|
|
}
|
|
|
|
/*
|
|
* Cleanup ptys/utmp only if privsep is disabled,
|
|
* or if running in monitor.
|
|
*/
|
|
if (!use_privsep || mm_is_monitor())
|
|
session_destroy_all(ssh, session_pty_cleanup2);
|
|
}
|
|
|
|
/* Return a name for the remote host that fits inside utmp_size */
|
|
|
|
const char *
|
|
session_get_remote_name_or_ip(struct ssh *ssh, u_int utmp_size, int use_dns)
|
|
{
|
|
const char *remote = "";
|
|
|
|
if (utmp_size > 0)
|
|
remote = auth_get_canonical_hostname(ssh, use_dns);
|
|
if (utmp_size == 0 || strlen(remote) > utmp_size)
|
|
remote = ssh_remote_ipaddr(ssh);
|
|
return remote;
|
|
}
|
|
|