* called by a name other than "ssh" or "Secure Shell".
*
* Copyright (c) 1999 Niels Provos. All rights reserved.
- * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
+ * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
*
* Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
* in Canada (German citizen).
*/
#include "includes.h"
-RCSID("$OpenBSD: ssh.c,v 1.201 2003/09/01 18:15:50 markus Exp $");
+RCSID("$OpenBSD: ssh.c,v 1.224 2004/07/28 09:40:29 markus Exp $");
#include <openssl/evp.h>
#include <openssl/err.h>
#include "xmalloc.h"
#include "packet.h"
#include "buffer.h"
+#include "bufaux.h"
#include "channels.h"
#include "key.h"
#include "authfd.h"
#include "authfile.h"
#include "pathnames.h"
+#include "dispatch.h"
#include "clientloop.h"
#include "log.h"
#include "readconf.h"
#include "sshconnect.h"
-#include "tildexpand.h"
-#include "dispatch.h"
#include "misc.h"
#include "kex.h"
#include "mac.h"
-#include "sshtty.h"
+#include "sshpty.h"
+#include "match.h"
+#include "msg.h"
+#include "monitor_fdpass.h"
+#include "uidswap.h"
#ifdef SMARTCARD
#include "scard.h"
#endif
-#ifdef HAVE___PROGNAME
extern char *__progname;
-#else
-char *__progname;
-#endif
/* Flag indicating whether debug mode is on. This can be set on the command line. */
int debug_flag = 0;
/* pid of proxycommand child process */
pid_t proxy_command_pid = 0;
+/* fd to control socket */
+int control_fd = -1;
+
+/* Only used in control client mode */
+volatile sig_atomic_t control_client_terminate = 0;
+u_int control_server_pid = 0;
+
/* Prints a help message to the user. This function never returns. */
static void
usage(void)
{
- fprintf(stderr, "Usage: %s [options] host [command]\n", __progname);
- fprintf(stderr, "Options:\n");
- fprintf(stderr, " -l user Log in using this user name.\n");
- fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n");
- fprintf(stderr, " -F config Config file (default: ~/%s).\n",
- _PATH_SSH_USER_CONFFILE);
- fprintf(stderr, " -A Enable authentication agent forwarding.\n");
- fprintf(stderr, " -a Disable authentication agent forwarding (default).\n");
- fprintf(stderr, " -X Enable X11 connection forwarding.\n");
- fprintf(stderr, " -x Disable X11 connection forwarding (default).\n");
- fprintf(stderr, " -i file Identity for public key authentication "
- "(default: ~/.ssh/identity)\n");
-#ifdef SMARTCARD
- fprintf(stderr, " -I reader Set smartcard reader.\n");
-#endif
- fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
- fprintf(stderr, " -T Do not allocate a tty.\n");
- fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
- fprintf(stderr, " Multiple -v increases verbosity.\n");
- fprintf(stderr, " -V Display version number only.\n");
- fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
- fprintf(stderr, " -f Fork into background after authentication.\n");
- fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
-
- fprintf(stderr, " -c cipher Select encryption algorithm\n");
- fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n");
- fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
- fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
- fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
- fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname);
- fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
- fprintf(stderr, " -D port Enable dynamic application-level port forwarding.\n");
- fprintf(stderr, " -C Enable compression.\n");
- fprintf(stderr, " -N Do not execute a shell or command.\n");
- fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
- fprintf(stderr, " -1 Force protocol version 1.\n");
- fprintf(stderr, " -2 Force protocol version 2.\n");
- fprintf(stderr, " -4 Use IPv4 only.\n");
- fprintf(stderr, " -6 Use IPv6 only.\n");
- fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
- fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n");
- fprintf(stderr, " -b addr Local IP address.\n");
+ fprintf(stderr,
+"usage: ssh [-1246AaCfghkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
+" [-D port] [-e escape_char] [-F configfile] [-i identity_file]\n"
+" [-L port:host:hostport] [-l login_name] [-m mac_spec] [-o option]\n"
+" [-p port] [-R port:host:hostport] [-S ctl] [user@]hostname [command]\n"
+ );
exit(1);
}
static int ssh_session(void);
static int ssh_session2(void);
static void load_public_identity_files(void);
+static void control_client(const char *path);
/*
* Main program for the ssh client.
int i, opt, exit_status;
u_short fwd_port, fwd_host_port;
char sfwd_port[6], sfwd_host_port[6];
- char *p, *cp, buf[256];
+ char *p, *cp, *line, buf[256];
struct stat st;
struct passwd *pw;
int dummy;
*/
original_real_uid = getuid();
original_effective_uid = geteuid();
-
+
/*
* Use uid-swapping to give up root privileges for the duration of
* option processing. We will re-instantiate the rights when we are
again:
while ((opt = getopt(ac, av,
- "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -1) {
+ "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNPR:S:TVXY")) != -1) {
switch (opt) {
case '1':
options.protocol = SSH_PROTO_1;
case 'X':
options.forward_x11 = 1;
break;
+ case 'Y':
+ options.forward_x11 = 1;
+ options.forward_x11_trusted = 1;
+ break;
case 'g':
options.gateway_ports = 1;
break;
options.forward_agent = 1;
break;
case 'k':
- /* ignored for backward compatibility */
+ options.gss_deleg_creds = 0;
break;
case 'i':
if (stat(optarg, &st) < 0) {
}
/* fallthrough */
case 'V':
- fprintf(stderr,
- "%s, SSH protocols %d.%d/%d.%d, %s\n",
- SSH_VERSION,
- PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
- PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
- SSLeay_version(SSLEAY_VERSION));
+ fprintf(stderr, "%s, %s\n",
+ SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
if (opt == 'V')
exit(0);
break;
if (ciphers_valid(optarg)) {
/* SSH2 only */
options.ciphers = xstrdup(optarg);
- options.cipher = SSH_CIPHER_ILLEGAL;
+ options.cipher = SSH_CIPHER_INVALID;
} else {
/* SSH1 only */
options.cipher = cipher_number(optarg);
exit(1);
}
break;
+ case 'M':
+ options.control_master =
+ (options.control_master >= 1) ? 2 : 1;
+ break;
case 'p':
options.port = a2port(optarg);
if (options.port == 0) {
break;
case 'o':
dummy = 1;
+ line = xstrdup(optarg);
if (process_config_line(&options, host ? host : "",
- optarg, "command-line", 0, &dummy) != 0)
+ line, "command-line", 0, &dummy) != 0)
exit(1);
+ xfree(line);
break;
case 's':
subsystem_flag = 1;
break;
+ case 'S':
+ if (options.control_path != NULL)
+ free(options.control_path);
+ options.control_path = xstrdup(optarg);
+ break;
case 'b':
options.bind_address = optarg;
break;
* file if the user specifies a config file on the command line.
*/
if (config != NULL) {
- if (!read_config_file(config, host, &options))
+ if (!read_config_file(config, host, &options, 0))
fatal("Can't open user config file %.100s: "
"%.100s", config, strerror(errno));
} else {
snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
_PATH_SSH_USER_CONFFILE);
- (void)read_config_file(buf, host, &options);
+ (void)read_config_file(buf, host, &options, 1);
/* Read systemwide configuration file after use config. */
- (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
+ (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
+ &options, 0);
}
/* Fill configuration defaults. */
strcmp(options.proxy_command, "none") == 0)
options.proxy_command = NULL;
+ if (options.control_path != NULL) {
+ options.control_path = tilde_expand_filename(
+ options.control_path, original_real_uid);
+ }
+ if (options.control_path != NULL && options.control_master == 0)
+ control_client(options.control_path); /* This doesn't return */
+
/* Open a connection to the remote host. */
if (ssh_connect(host, &hostaddr, options.port,
options.address_family, options.connection_attempts,
* user's home directory if it happens to be on a NFS volume where
* root is mapped to nobody.
*/
- seteuid(original_real_uid);
- setuid(original_real_uid);
+ if (original_effective_uid == 0) {
+ PRIV_START;
+ permanently_set_uid(pw);
+ }
/*
* Now that we are back to our own permissions, create ~/.ssh
exit_status = compat20 ? ssh_session2() : ssh_session();
packet_close();
+ if (options.control_path != NULL && control_fd != -1)
+ unlink(options.control_path);
+
/*
- * Send SIGHUP to proxy command if used. We don't wait() in
+ * Send SIGHUP to proxy command if used. We don't wait() in
* case it hangs and instead rely on init to reap the child
*/
if (proxy_command_pid > 1)
return exit_status;
}
+#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
+
static void
x11_get_proto(char **_proto, char **_data)
{
+ char cmd[1024];
char line[512];
+ char xdisplay[512];
static char proto[512], data[512];
FILE *f;
- int got_data = 0, i;
- char *display;
+ int got_data = 0, generated = 0, do_unlink = 0, i;
+ char *display, *xauthdir, *xauthfile;
struct stat st;
+ xauthdir = xauthfile = NULL;
*_proto = proto;
*_data = data;
proto[0] = data[0] = '\0';
+
if (!options.xauth_location ||
(stat(options.xauth_location, &st) == -1)) {
debug("No xauth program.");
debug("x11_get_proto: DISPLAY not set");
return;
}
- /* Try to get Xauthority information for the display. */
- if (strncmp(display, "localhost:", 10) == 0)
- /*
- * Handle FamilyLocal case where $DISPLAY does
- * not match an authorization entry. For this we
- * just try "xauth list unix:displaynum.screennum".
- * XXX: "localhost" match to determine FamilyLocal
- * is not perfect.
- */
- snprintf(line, sizeof line, "%s list unix:%s 2>"
- _PATH_DEVNULL, options.xauth_location, display+10);
- else
- snprintf(line, sizeof line, "%s list %.200s 2>"
- _PATH_DEVNULL, options.xauth_location, display);
- debug2("x11_get_proto: %s", line);
- f = popen(line, "r");
+ /*
+ * Handle FamilyLocal case where $DISPLAY does
+ * not match an authorization entry. For this we
+ * just try "xauth list unix:displaynum.screennum".
+ * XXX: "localhost" match to determine FamilyLocal
+ * is not perfect.
+ */
+ if (strncmp(display, "localhost:", 10) == 0) {
+ snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
+ display + 10);
+ display = xdisplay;
+ }
+ if (options.forward_x11_trusted == 0) {
+ xauthdir = xmalloc(MAXPATHLEN);
+ xauthfile = xmalloc(MAXPATHLEN);
+ strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
+ if (mkdtemp(xauthdir) != NULL) {
+ do_unlink = 1;
+ snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
+ xauthdir);
+ snprintf(cmd, sizeof(cmd),
+ "%s -f %s generate %s " SSH_X11_PROTO
+ " untrusted timeout 1200 2>" _PATH_DEVNULL,
+ options.xauth_location, xauthfile, display);
+ debug2("x11_get_proto: %s", cmd);
+ if (system(cmd) == 0)
+ generated = 1;
+ }
+ }
+ snprintf(cmd, sizeof(cmd),
+ "%s %s%s list %s . 2>" _PATH_DEVNULL,
+ options.xauth_location,
+ generated ? "-f " : "" ,
+ generated ? xauthfile : "",
+ display);
+ debug2("x11_get_proto: %s", cmd);
+ f = popen(cmd, "r");
if (f && fgets(line, sizeof(line), f) &&
sscanf(line, "%*s %511s %511s", proto, data) == 2)
got_data = 1;
if (f)
pclose(f);
}
+
+ if (do_unlink) {
+ unlink(xauthfile);
+ rmdir(xauthdir);
+ }
+ if (xauthdir)
+ xfree(xauthdir);
+ if (xauthfile)
+ xfree(xauthfile);
+
/*
* If we didn't get authentication data, just make up some
* data. The forwarding code will check the validity of the
* for the local connection.
*/
if (!got_data) {
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
- logit("Warning: No xauth data; using fake authentication data for X11 forwarding.");
- strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto);
+ logit("Warning: No xauth data; "
+ "using fake authentication data for X11 forwarding.");
+ strlcpy(proto, SSH_X11_PROTO, sizeof proto);
for (i = 0; i < 16; i++) {
if (i % 4 == 0)
- rand = arc4random();
- snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff);
- rand >>= 8;
+ rnd = arc4random();
+ snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
+ rnd & 0xff);
+ rnd >>= 8;
}
}
}
}
static void
-client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
+ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
{
int id, len;
}
void
-client_global_request_reply(int type, u_int32_t seq, void *ctxt)
+client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
{
int i;
i = client_global_request_id++;
- if (i >= options.num_remote_forwards) {
- debug("client_global_request_reply: too many replies %d > %d",
- i, options.num_remote_forwards);
+ if (i >= options.num_remote_forwards)
return;
- }
debug("remote forward %s for: listen %d, connect %s:%d",
type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
options.remote_forwards[i].port,
options.remote_forwards[i].port);
}
-/* request pty/x11/agent/tcpfwd/shell for channel */
static void
-ssh_session2_setup(int id, void *arg)
+ssh_control_listener(void)
{
- int len;
- int interactive = 0;
- struct termios tio;
+ struct sockaddr_un addr;
+ mode_t old_umask;
+ int addr_len;
- debug2("ssh_session2_setup: id %d", id);
+ if (options.control_path == NULL || options.control_master <= 0)
+ return;
- if (tty_flag) {
- struct winsize ws;
- char *cp;
- cp = getenv("TERM");
- if (!cp)
- cp = "";
- /* Store window size in the packet. */
- if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
- memset(&ws, 0, sizeof(ws));
+ memset(&addr, '\0', sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ addr_len = offsetof(struct sockaddr_un, sun_path) +
+ strlen(options.control_path) + 1;
- channel_request_start(id, "pty-req", 0);
- packet_put_cstring(cp);
- packet_put_int(ws.ws_col);
- packet_put_int(ws.ws_row);
- packet_put_int(ws.ws_xpixel);
- packet_put_int(ws.ws_ypixel);
- tio = get_saved_tio();
- tty_make_modes(/*ignored*/ 0, &tio);
- packet_send();
- interactive = 1;
- /* XXX wait for reply */
+ if (strlcpy(addr.sun_path, options.control_path,
+ sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
+ fatal("ControlPath too long");
+
+ if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
+ fatal("%s socket(): %s\n", __func__, strerror(errno));
+
+ old_umask = umask(0177);
+ if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
+ control_fd = -1;
+ if (errno == EINVAL)
+ fatal("ControlSocket %s already exists",
+ options.control_path);
+ else
+ fatal("%s bind(): %s\n", __func__, strerror(errno));
}
- if (options.forward_x11 &&
- getenv("DISPLAY") != NULL) {
+ umask(old_umask);
+
+ if (listen(control_fd, 64) == -1)
+ fatal("%s listen(): %s\n", __func__, strerror(errno));
+
+ set_nonblock(control_fd);
+}
+
+/* request pty/x11/agent/tcpfwd/shell for channel */
+static void
+ssh_session2_setup(int id, void *arg)
+{
+ extern char **environ;
+
+ int interactive = tty_flag;
+ if (options.forward_x11 && getenv("DISPLAY") != NULL) {
char *proto, *data;
/* Get reasonable local authentication information. */
x11_get_proto(&proto, &data);
packet_send();
}
- len = buffer_len(&command);
- if (len > 0) {
- if (len > 900)
- len = 900;
- if (subsystem_flag) {
- debug("Sending subsystem: %.*s", len, (u_char *)buffer_ptr(&command));
- channel_request_start(id, "subsystem", /*want reply*/ 1);
- /* register callback for reply */
- /* XXX we assume that client_loop has already been called */
- dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply);
- dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply);
- } else {
- debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
- channel_request_start(id, "exec", 0);
- }
- packet_put_string(buffer_ptr(&command), buffer_len(&command));
- packet_send();
- } else {
- channel_request_start(id, "shell", 0);
- packet_send();
- }
+ client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
+ NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
packet_set_interactive(interactive);
}
channel_send_open(c->self);
if (!no_shell_flag)
- channel_register_confirm(c->self, ssh_session2_setup);
+ channel_register_confirm(c->self, ssh_session2_setup, NULL);
return c->self;
}
/* XXX should be pre-session */
ssh_init_forwarding();
+ ssh_control_listener();
if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
id = ssh_session2_open();
options.identity_keys[i] = public;
}
}
+
+static void
+control_client_sighandler(int signo)
+{
+ control_client_terminate = signo;
+}
+
+static void
+control_client_sigrelay(int signo)
+{
+ if (control_server_pid > 1)
+ kill(control_server_pid, signo);
+}
+
+static int
+env_permitted(char *env)
+{
+ int i;
+ char name[1024], *cp;
+
+ strlcpy(name, env, sizeof(name));
+ if ((cp = strchr(name, '=')) == NULL)
+ return (0);
+
+ *cp = '\0';
+
+ for (i = 0; i < options.num_send_env; i++)
+ if (match_pattern(name, options.send_env[i]))
+ return (1);
+
+ return (0);
+}
+
+static void
+control_client(const char *path)
+{
+ struct sockaddr_un addr;
+ int i, r, sock, exitval, num_env, addr_len;
+ Buffer m;
+ char *cp;
+ extern char **environ;
+
+ memset(&addr, '\0', sizeof(addr));
+ addr.sun_family = AF_UNIX;
+ addr_len = offsetof(struct sockaddr_un, sun_path) +
+ strlen(path) + 1;
+
+ if (strlcpy(addr.sun_path, path,
+ sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
+ fatal("ControlPath too long");
+
+ if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
+ fatal("%s socket(): %s", __func__, strerror(errno));
+
+ if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1)
+ fatal("Couldn't connect to %s: %s", path, strerror(errno));
+
+ if ((cp = getenv("TERM")) == NULL)
+ cp = "";
+
+ buffer_init(&m);
+
+ /* Get PID of controlee */
+ if (ssh_msg_recv(sock, &m) == -1)
+ fatal("%s: msg_recv", __func__);
+ if (buffer_get_char(&m) != 0)
+ fatal("%s: wrong version", __func__);
+ /* Connection allowed? */
+ if (buffer_get_int(&m) != 1)
+ fatal("Connection to master denied");
+ control_server_pid = buffer_get_int(&m);
+
+ buffer_clear(&m);
+ buffer_put_int(&m, tty_flag);
+ buffer_put_int(&m, subsystem_flag);
+ buffer_put_cstring(&m, cp);
+
+ buffer_append(&command, "\0", 1);
+ buffer_put_cstring(&m, buffer_ptr(&command));
+
+ if (options.num_send_env == 0 || environ == NULL) {
+ buffer_put_int(&m, 0);
+ } else {
+ /* Pass environment */
+ num_env = 0;
+ for (i = 0; environ[i] != NULL; i++)
+ if (env_permitted(environ[i]))
+ num_env++; /* Count */
+
+ buffer_put_int(&m, num_env);
+
+ for (i = 0; environ[i] != NULL && num_env >= 0; i++)
+ if (env_permitted(environ[i])) {
+ num_env--;
+ buffer_put_cstring(&m, environ[i]);
+ }
+ }
+
+ if (ssh_msg_send(sock, /* version */0, &m) == -1)
+ fatal("%s: msg_send", __func__);
+
+ mm_send_fd(sock, STDIN_FILENO);
+ mm_send_fd(sock, STDOUT_FILENO);
+ mm_send_fd(sock, STDERR_FILENO);
+
+ /* Wait for reply, so master has a chance to gather ttymodes */
+ buffer_clear(&m);
+ if (ssh_msg_recv(sock, &m) == -1)
+ fatal("%s: msg_recv", __func__);
+ if (buffer_get_char(&m) != 0)
+ fatal("%s: master returned error", __func__);
+ buffer_free(&m);
+
+ signal(SIGINT, control_client_sighandler);
+ signal(SIGTERM, control_client_sighandler);
+ signal(SIGWINCH, control_client_sigrelay);
+
+ if (tty_flag)
+ enter_raw_mode();
+
+ /* Stick around until the controlee closes the client_fd */
+ exitval = 0;
+ for (;!control_client_terminate;) {
+ r = read(sock, &exitval, sizeof(exitval));
+ if (r == 0) {
+ debug2("Received EOF from master");
+ break;
+ }
+ if (r > 0)
+ debug2("Received exit status from master %d", exitval);
+ if (r == -1 && errno != EINTR)
+ fatal("%s: read %s", __func__, strerror(errno));
+ }
+
+ if (control_client_terminate)
+ debug2("Exiting on signal %d", control_client_terminate);
+
+ close(sock);
+
+ leave_raw_mode();
+
+ if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
+ fprintf(stderr, "Connection to master closed.\r\n");
+
+ exit(exitval);
+}
andersk / gssapi-openssh.git / blobdiff