108 ssh.c
View file
@@ -1,4 +1,4 @@
/* $OpenBSD: ssh.c,v 1.465 2017/10/21 23:06:24 millert Exp $ */
/* $OpenBSD: ssh.c,v 1.466 2017/10/23 05:08:00 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -168,6 +168,10 @@ char *config = NULL;
*/
char *host;

/* Various strings used to to percent_expand() arguments */
static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
static char uidstr[32], *host_arg, *conn_hash_hex;

/* socket address the host resolves to */
struct sockaddr_storage hostaddr;

@@ -208,8 +212,8 @@ usage(void)
exit(255);
}

static int ssh_session2(struct ssh *);
static void load_public_identity_files(void);
static int ssh_session2(struct ssh *, struct passwd *);
static void load_public_identity_files(struct passwd *);
static void main_sigchld_handler(int);

/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
@@ -456,28 +460,28 @@ resolve_canonicalize(char **hostp, int port)
* file if the user specifies a config file on the command line.
*/
static void
process_config_files(const char *host_arg, struct passwd *pw, int post_canon)
process_config_files(const char *host_name, struct passwd *pw, int post_canon)
{
char buf[PATH_MAX];
int r;

if (config != NULL) {
if (strcasecmp(config, "none") != 0 &&
!read_config_file(config, pw, host, host_arg, &options,
!read_config_file(config, pw, host, host_name, &options,
SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
fatal("Can't open user config file %.100s: "
"%.100s", config, strerror(errno));
} else {
r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
_PATH_SSH_USER_CONFFILE);
if (r > 0 && (size_t)r < sizeof(buf))
(void)read_config_file(buf, pw, host, host_arg,
(void)read_config_file(buf, pw, host, host_name,
&options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
(post_canon ? SSHCONF_POSTCANON : 0));

/* Read systemwide configuration file after user config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
host, host_arg, &options,
host, host_name, &options,
post_canon ? SSHCONF_POSTCANON : 0);
}
}
@@ -511,9 +515,8 @@ main(int ac, char **av)
struct ssh *ssh = NULL;
int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
int config_test = 0, opt_terminated = 0;
char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile;
char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
char cname[NI_MAXHOST], uidstr[32], *conn_hash_hex;
char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile;
char cname[NI_MAXHOST];
struct stat st;
struct passwd *pw;
extern int optind, optreset;
@@ -1203,6 +1206,7 @@ main(int ac, char **av)
if (options.user == NULL)
options.user = xstrdup(pw->pw_name);

/* Set up strings used to percent_expand() arguments */
if (gethostname(thishost, sizeof(thishost)) == -1)
fatal("gethostname: %s", strerror(errno));
strlcpy(shorthost, thishost, sizeof(shorthost));
@@ -1220,24 +1224,11 @@ main(int ac, char **av)
ssh_digest_free(md);
conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));

if (options.local_command != NULL) {
debug3("expanding LocalCommand: %s", options.local_command);
cp = options.local_command;
options.local_command = percent_expand(cp,
"C", conn_hash_hex,
"L", shorthost,
"d", pw->pw_dir,
"h", host,
"l", thishost,
"n", host_arg,
"p", portstr,
"r", options.user,
"u", pw->pw_name,
(char *)NULL);
debug3("expanded LocalCommand: %s", options.local_command);
free(cp);
}

/*
* Expand tokens in arguments. NB. LocalCommand is expanded later,
* after port-forwarding is set up, so it may pick up any local
* tunnel interface name allocated.
*/
if (options.remote_command != NULL) {
debug3("expanding RemoteCommand: %s", options.remote_command);
cp = options.remote_command;
@@ -1256,7 +1247,6 @@ main(int ac, char **av)
free(cp);
buffer_append(&command, options.remote_command,
strlen(options.remote_command));

}

if (options.control_path != NULL) {
@@ -1427,7 +1417,7 @@ main(int ac, char **av)
}
}
/* load options.identity_files */
load_public_identity_files();
load_public_identity_files(pw);

/* optionally set the SSH_AUTHSOCKET_ENV_NAME varibale */
if (options.identity_agent &&
@@ -1491,7 +1481,7 @@ main(int ac, char **av)
}

skip_connect:
exit_status = ssh_session2(ssh);
exit_status = ssh_session2(ssh, pw);
packet_close();

if (options.control_path != NULL && muxserver_sock != -1)
@@ -1650,7 +1640,7 @@ ssh_init_stdio_forwarding(struct ssh *ssh)
}

static void
ssh_init_forwarding(struct ssh *ssh)
ssh_init_forwarding(struct ssh *ssh, char **ifname)
{
int success = 0;
int i;
@@ -1708,8 +1698,9 @@ ssh_init_forwarding(struct ssh *ssh)

/* Initiate tunnel forwarding. */
if (options.tun_open != SSH_TUNMODE_NO) {
if (client_request_tun_fwd(ssh, options.tun_open,
options.tun_local, options.tun_remote) == -1) {
if ((*ifname = client_request_tun_fwd(ssh,
options.tun_open, options.tun_local,
options.tun_remote)) == NULL) {
if (options.exit_on_forward_failure)
fatal("Could not request tunnel forwarding.");
else
@@ -1824,14 +1815,35 @@ ssh_session2_open(struct ssh *ssh)
}

static int
ssh_session2(struct ssh *ssh)
ssh_session2(struct ssh *ssh, struct passwd *pw)
{
int id = -1;
char *cp, *tun_fwd_ifname = NULL;

/* XXX should be pre-session */
if (!options.control_persist)
ssh_init_stdio_forwarding(ssh);
ssh_init_forwarding(ssh);

ssh_init_forwarding(ssh, &tun_fwd_ifname);

if (options.local_command != NULL) {
debug3("expanding LocalCommand: %s", options.local_command);
cp = options.local_command;
options.local_command = percent_expand(cp,
"C", conn_hash_hex,
"L", shorthost,
"d", pw->pw_dir,
"h", host,
"l", thishost,
"n", host_arg,
"p", portstr,
"r", options.user,
"u", pw->pw_name,
"T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
(char *)NULL);
debug3("expanded LocalCommand: %s", options.local_command);
free(cp);
}

/* Start listening for multiplex clients */
if (!packet_get_mux())
@@ -1907,12 +1919,10 @@ ssh_session2(struct ssh *ssh)

/* Loads all IdentityFile and CertificateFile keys */
static void
load_public_identity_files(void)
load_public_identity_files(struct passwd *pw)
{
char *filename, *cp, thishost[NI_MAXHOST];
char *pwdir = NULL, *pwname = NULL;
char *filename, *cp;
struct sshkey *public;
struct passwd *pw;
int i;
u_int n_ids, n_certs;
char *identity_files[SSH_MAX_IDENTITY_FILES];
@@ -1951,11 +1961,6 @@ load_public_identity_files(void)
#endif /* ENABLE_PKCS11 */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("load_public_identity_files: getpwuid failed");
pwname = xstrdup(pw->pw_name);
pwdir = xstrdup(pw->pw_dir);
if (gethostname(thishost, sizeof(thishost)) == -1)
fatal("load_public_identity_files: gethostname: %s",
strerror(errno));
for (i = 0; i < options.num_identity_files; i++) {
if (n_ids >= SSH_MAX_IDENTITY_FILES ||
strcasecmp(options.identity_files[i], "none") == 0) {
@@ -1965,8 +1970,8 @@ load_public_identity_files(void)
}
cp = tilde_expand_filename(options.identity_files[i],
original_real_uid);
filename = percent_expand(cp, "d", pwdir,
"u", pwname, "l", thishost, "h", host,
filename = percent_expand(cp, "d", pw->pw_dir,
"u", pw->pw_name, "l", thishost, "h", host,
"r", options.user, (char *)NULL);
free(cp);
public = key_load_public(filename, NULL);
@@ -2011,8 +2016,8 @@ load_public_identity_files(void)
for (i = 0; i < options.num_certificate_files; i++) {
cp = tilde_expand_filename(options.certificate_files[i],
original_real_uid);
filename = percent_expand(cp, "d", pwdir,
"u", pwname, "l", thishost, "h", host,
filename = percent_expand(cp, "d", pw->pw_dir,
"u", pw->pw_name, "l", thishost, "h", host,
"r", options.user, (char *)NULL);
free(cp);

@@ -2045,11 +2050,6 @@ load_public_identity_files(void)
memcpy(options.certificate_files,
certificate_files, sizeof(certificate_files));
memcpy(options.certificates, certificates, sizeof(certificates));

explicit_bzero(pwname, strlen(pwname));
free(pwname);
explicit_bzero(pwdir, strlen(pwdir));
free(pwdir);
}

static void
16 ssh_config.5
View file
@@ -33,8 +33,8 @@
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.\" $OpenBSD: ssh_config.5,v 1.260 2017/10/21 23:06:24 millert Exp $
.Dd $Mdocdate: October 21 2017 $
.\" $OpenBSD: ssh_config.5,v 1.261 2017/10/23 05:08:00 djm Exp $
.Dd $Mdocdate: October 23 2017 $
.Dt SSH_CONFIG 5
.Os
.Sh NAME
@@ -1713,6 +1713,16 @@ The original remote hostname, as given on the command line.
The remote port.
.It %r
The remote username.
.It \&%T
The local
.Xr tun 4
or
.Xr tap 4
network interface assigned if
.Cm Tunnel
forwarding was requested, or
.Cm NONE
otherwise.
.It %u
The local username.
.El
@@ -1735,7 +1745,7 @@ and
accept the tokens %%, %d, %h, %l, %r, and %u.
.Pp
.Cm LocalCommand
accepts the tokens %%, %C, %d, %h, %l, %n, %p, %r, and %u.
accepts the tokens %%, %C, %d, %h, %l, %n, %p, %r, %T, and %u.
.Pp
.Cm ProxyCommand
accepts the tokens %%, %h, %p, and %r.