void
session_setup_sia(struct passwd *pw, char *tty)
{
SIAENTITY *ent = NULL;
const char *host;
host = get_canonical_hostname(options.use_dns);
if (sia_ses_init(&ent, saved_argc, saved_argv, host, pw->pw_name,
tty, 0, NULL) != SIASUCCESS)
fatal("sia_ses_init failed");
if (sia_make_entity_pwd(pw, ent) != SIASUCCESS) {
sia_ses_release(&ent);
fatal("sia_make_entity_pwd failed");
}
ent->authtype = SIA_A_NONE;
if (sia_ses_estab(sia_collect_trm, ent) != SIASUCCESS)
fatal("Couldn't establish session for %s from %s",
pw->pw_name, host);
if (sia_ses_launch(sia_collect_trm, ent) != SIASUCCESS)
fatal("Couldn't launch session for %s from %s",
pw->pw_name, host);
sia_ses_release(&ent);
setuid(0);
permanently_set_uid(pw);
}
static void
privsep_preauth_child(void)
{
u_int32_t rand[256];
gid_t gidset[2];
struct passwd *pw;
int i;
/* Enable challenge-response authentication for privilege separation */
privsep_challenge_enable();
for (i = 0; i < 256; i++)
rand[i] = arc4random();
RAND_seed(rand, sizeof(rand));
/* Demote the private keys to public keys. */
demote_sensitive_data();
if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
fatal("Privilege separation user %s does not exist",
SSH_PRIVSEP_USER);
memset(pw->pw_passwd, 0, strlen(pw->pw_passwd));
endpwent();
/* Change our root directory*/
if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
strerror(errno));
if (chdir("/") == -1)
fatal("chdir(\"/\"): %s", strerror(errno));
/* Drop our privileges */
debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
(u_int)pw->pw_gid);
#if 0
/* XXX not ready, to heavy after chroot */
do_setusercontext(pw);
#else
gidset[0] = pw->pw_gid;
if (setgid(pw->pw_gid) < 0)
fatal("setgid failed for %u", pw->pw_gid );
if (setgroups(1, gidset) < 0)
fatal("setgroups: %.100s", strerror(errno));
permanently_set_uid(pw);
#endif
}
/*
* Main program for the ssh client.
*/
int
main(int ac, char **av)
{
int i, r, opt, exit_status, use_syslog;
char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg;
char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
struct stat st;
struct passwd *pw;
int dummy, timeout_ms;
extern int optind, optreset;
extern char *optarg;
struct servent *sp;
Forward fwd;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
__progname = ssh_get_progname(av[0]);
#ifndef HAVE_SETPROCTITLE
/* Prepare for later setproctitle emulation */
/* Save argv so it isn't clobbered by setproctitle() emulation */
saved_av = xcalloc(ac + 1, sizeof(*saved_av));
for (i = 0; i < ac; i++)
saved_av[i] = xstrdup(av[i]);
saved_av[i] = NULL;
compat_init_setproctitle(ac, av);
av = saved_av;
#endif
/*
* Discard other fds that are hanging around. These can cause problem
* with backgrounded ssh processes started by ControlPersist.
*/
closefrom(STDERR_FILENO + 1);
/*
* Save the original real uid. It will be needed later (uid-swapping
* may clobber the real uid).
*/
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
* ready to create the privileged port, and will permanently drop
* them when the port has been created (actually, when the connection
* has been made, as we may need to create the port several times).
*/
PRIV_END;
#ifdef HAVE_SETRLIMIT
/* If we are installed setuid root be careful to not drop core. */
if (original_real_uid != original_effective_uid) {
struct rlimit rlim;
rlim.rlim_cur = rlim.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &rlim) < 0)
fatal("setrlimit failed: %.100s", strerror(errno));
}
#endif
/* Get user data. */
pw = getpwuid(original_real_uid);
if (!pw) {
logit("You don't exist, go away!");
exit(255);
}
/* Take a copy of the returned structure. */
pw = pwcopy(pw);
/*
* Set our umask to something reasonable, as some files are created
* with the default umask. This will make them world-readable but
* writable only by the owner, which is ok for all files for which we
* don't set the modes explicitly.
*/
umask(022);
/*
* Initialize option structure to indicate that no values have been
* set.
*/
initialize_options(&options);
/* Parse command-line arguments. */
host = NULL;
use_syslog = 0;
argv0 = av[0];
again:
while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
"ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
switch (opt) {
case '1':
options.protocol = SSH_PROTO_1;
break;
case '2':
options.protocol = SSH_PROTO_2;
break;
case '4':
options.address_family = AF_INET;
break;
case '6':
options.address_family = AF_INET6;
break;
case 'n':
stdin_null_flag = 1;
break;
case 'f':
fork_after_authentication_flag = 1;
stdin_null_flag = 1;
break;
case 'x':
options.forward_x11 = 0;
break;
case 'X':
options.forward_x11 = 1;
break;
case 'y':
use_syslog = 1;
break;
case 'Y':
options.forward_x11 = 1;
options.forward_x11_trusted = 1;
break;
case 'g':
options.gateway_ports = 1;
break;
case 'O':
if (stdio_forward_host != NULL)
fatal("Cannot specify multiplexing "
"command with -W");
else if (muxclient_command != 0)
fatal("Multiplexing command already specified");
if (strcmp(optarg, "check") == 0)
muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
else if (strcmp(optarg, "forward") == 0)
muxclient_command = SSHMUX_COMMAND_FORWARD;
else if (strcmp(optarg, "exit") == 0)
muxclient_command = SSHMUX_COMMAND_TERMINATE;
else if (strcmp(optarg, "stop") == 0)
muxclient_command = SSHMUX_COMMAND_STOP;
else if (strcmp(optarg, "cancel") == 0)
muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
else
fatal("Invalid multiplex command.");
break;
case 'P': /* deprecated */
options.use_privileged_port = 0;
break;
case 'a':
options.forward_agent = 0;
break;
case 'A':
options.forward_agent = 1;
break;
case 'k':
options.gss_deleg_creds = 0;
break;
case 'K':
options.gss_authentication = 1;
options.gss_deleg_creds = 1;
break;
case 'i':
if (stat(optarg, &st) < 0) {
fprintf(stderr, "Warning: Identity file %s "
"not accessible: %s.\n", optarg,
strerror(errno));
break;
}
if (options.num_identity_files >=
SSH_MAX_IDENTITY_FILES)
fatal("Too many identity files specified "
"(max %d)", SSH_MAX_IDENTITY_FILES);
options.identity_files[options.num_identity_files++] =
xstrdup(optarg);
break;
case 'I':
#ifdef ENABLE_PKCS11
options.pkcs11_provider = xstrdup(optarg);
#else
fprintf(stderr, "no support for PKCS#11.\n");
#endif
break;
case 't':
if (options.request_tty == REQUEST_TTY_YES)
options.request_tty = REQUEST_TTY_FORCE;
else
options.request_tty = REQUEST_TTY_YES;
break;
case 'v':
if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
} else {
if (options.log_level < SYSLOG_LEVEL_DEBUG3)
options.log_level++;
break;
}
/* FALLTHROUGH */
case 'V':
fprintf(stderr, "%s, %s\n",
SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
if (opt == 'V')
exit(0);
break;
case 'w':
if (options.tun_open == -1)
options.tun_open = SSH_TUNMODE_DEFAULT;
options.tun_local = a2tun(optarg, &options.tun_remote);
if (options.tun_local == SSH_TUNID_ERR) {
fprintf(stderr,
"Bad tun device '%s'\n", optarg);
exit(255);
}
break;
case 'W':
if (stdio_forward_host != NULL)
fatal("stdio forward already specified");
if (muxclient_command != 0)
fatal("Cannot specify stdio forward with -O");
if (parse_forward(&fwd, optarg, 1, 0)) {
stdio_forward_host = fwd.listen_host;
stdio_forward_port = fwd.listen_port;
xfree(fwd.connect_host);
} else {
fprintf(stderr,
"Bad stdio forwarding specification '%s'\n",
optarg);
exit(255);
}
options.request_tty = REQUEST_TTY_NO;
no_shell_flag = 1;
options.clear_forwardings = 1;
options.exit_on_forward_failure = 1;
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'e':
if (optarg[0] == '^' && optarg[2] == 0 &&
(u_char) optarg[1] >= 64 &&
(u_char) optarg[1] < 128)
options.escape_char = (u_char) optarg[1] & 31;
else if (strlen(optarg) == 1)
options.escape_char = (u_char) optarg[0];
else if (strcmp(optarg, "none") == 0)
options.escape_char = SSH_ESCAPECHAR_NONE;
else {
fprintf(stderr, "Bad escape character '%s'.\n",
optarg);
exit(255);
}
break;
case 'c':
if (ciphers_valid(optarg)) {
/* SSH2 only */
options.ciphers = xstrdup(optarg);
options.cipher = SSH_CIPHER_INVALID;
} else {
/* SSH1 only */
options.cipher = cipher_number(optarg);
if (options.cipher == -1) {
fprintf(stderr,
"Unknown cipher type '%s'\n",
optarg);
exit(255);
}
if (options.cipher == SSH_CIPHER_3DES)
options.ciphers = "3des-cbc";
else if (options.cipher == SSH_CIPHER_BLOWFISH)
options.ciphers = "blowfish-cbc";
else
options.ciphers = (char *)-1;
}
break;
case 'm':
if (mac_valid(optarg))
options.macs = xstrdup(optarg);
else {
fprintf(stderr, "Unknown mac type '%s'\n",
optarg);
exit(255);
}
break;
case 'M':
if (options.control_master == SSHCTL_MASTER_YES)
options.control_master = SSHCTL_MASTER_ASK;
else
options.control_master = SSHCTL_MASTER_YES;
break;
case 'p':
options.port = a2port(optarg);
if (options.port <= 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(255);
}
break;
case 'l':
options.user = optarg;
break;
case 'L':
if (parse_forward(&fwd, optarg, 0, 0))
add_local_forward(&options, &fwd);
else {
fprintf(stderr,
"Bad local forwarding specification '%s'\n",
optarg);
exit(255);
}
break;
case 'R':
if (parse_forward(&fwd, optarg, 0, 1)) {
add_remote_forward(&options, &fwd);
} else {
fprintf(stderr,
"Bad remote forwarding specification "
"'%s'\n", optarg);
exit(255);
}
break;
case 'D':
if (parse_forward(&fwd, optarg, 1, 0)) {
add_local_forward(&options, &fwd);
} else {
fprintf(stderr,
"Bad dynamic forwarding specification "
"'%s'\n", optarg);
exit(255);
}
break;
case 'C':
options.compression = 1;
break;
case 'N':
no_shell_flag = 1;
options.request_tty = REQUEST_TTY_NO;
break;
case 'T':
options.request_tty = REQUEST_TTY_NO;
break;
case 'o':
dummy = 1;
line = xstrdup(optarg);
if (process_config_line(&options, host ? host : "",
line, "command-line", 0, &dummy) != 0)
exit(255);
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;
case 'F':
config = optarg;
break;
default:
usage();
}
}
ac -= optind;
av += optind;
if (ac > 0 && !host) {
if (strrchr(*av, '@')) {
p = xstrdup(*av);
cp = strrchr(p, '@');
if (cp == NULL || cp == p)
usage();
options.user = p;
*cp = '\0';
host = ++cp;
} else
host = *av;
if (ac > 1) {
optind = optreset = 1;
goto again;
}
ac--, av++;
}
/* Check that we got a host name. */
if (!host)
usage();
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
/* Initialize the command to execute on remote host. */
buffer_init(&command);
if (options.request_tty == REQUEST_TTY_YES ||
options.request_tty == REQUEST_TTY_FORCE)
tty_flag = 1;
/*
* Save the command to execute on the remote host in a buffer. There
* is no limit on the length of the command, except by the maximum
* packet size. Also sets the tty flag if there is no command.
*/
if (!ac) {
/* No command specified - execute shell on a tty. */
tty_flag = options.request_tty != REQUEST_TTY_NO;
if (subsystem_flag) {
fprintf(stderr,
"You must specify a subsystem to invoke.\n");
usage();
}
} else {
/* A command has been specified. Store it into the buffer. */
for (i = 0; i < ac; i++) {
if (i)
buffer_append(&command, " ", 1);
buffer_append(&command, av[i], strlen(av[i]));
}
}
/* Cannot fork to background if no command. */
if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
!no_shell_flag)
fatal("Cannot fork into background without a command "
"to execute.");
/* Allocate a tty by default if no command specified. */
if (buffer_len(&command) == 0)
tty_flag = options.request_tty != REQUEST_TTY_NO;
/* Force no tty */
if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0)
tty_flag = 0;
/* Do not allocate a tty if stdin is not a tty. */
if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
options.request_tty != REQUEST_TTY_FORCE) {
if (tty_flag)
logit("Pseudo-terminal will not be allocated because "
"stdin is not a terminal.");
tty_flag = 0;
}
/*
* Initialize "log" output. Since we are the client all output
* actually goes to stderr.
*/
log_init(argv0,
options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
SYSLOG_FACILITY_USER, !use_syslog);
/*
* Read per-user configuration file. Ignore the system wide config
* file if the user specifies a config file on the command line.
*/
if (config != NULL) {
if (!read_config_file(config, host, &options, 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, host, &options, 1);
/* Read systemwide configuration file after user config. */
(void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
&options, 0);
}
/* Fill configuration defaults. */
fill_default_options(&options);
channel_set_af(options.address_family);
/* reinit */
log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
seed_rng();
if (options.user == NULL)
options.user = xstrdup(pw->pw_name);
/* Get default port if port has not been set. */
if (options.port == 0) {
sp = getservbyname(SSH_SERVICE_NAME, "tcp");
options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
}
/* preserve host name given on command line for %n expansion */
host_arg = host;
if (options.hostname != NULL) {
host = percent_expand(options.hostname,
"h", host, (char *)NULL);
}
if (gethostname(thishost, sizeof(thishost)) == -1)
fatal("gethostname: %s", strerror(errno));
strlcpy(shorthost, thishost, sizeof(shorthost));
shorthost[strcspn(thishost, ".")] = '\0';
snprintf(portstr, sizeof(portstr), "%d", options.port);
if (options.local_command != NULL) {
debug3("expanding LocalCommand: %s", options.local_command);
cp = options.local_command;
options.local_command = percent_expand(cp, "d", pw->pw_dir,
"h", host, "l", thishost, "n", host_arg, "r", options.user,
"p", portstr, "u", pw->pw_name, "L", shorthost,
(char *)NULL);
debug3("expanded LocalCommand: %s", options.local_command);
xfree(cp);
}
/* force lowercase for hostkey matching */
if (options.host_key_alias != NULL) {
for (p = options.host_key_alias; *p; p++)
if (isupper(*p))
*p = (char)tolower(*p);
}
if (options.proxy_command != NULL &&
strcmp(options.proxy_command, "none") == 0) {
xfree(options.proxy_command);
options.proxy_command = NULL;
}
if (options.control_path != NULL &&
strcmp(options.control_path, "none") == 0) {
xfree(options.control_path);
options.control_path = NULL;
}
if (options.control_path != NULL) {
cp = tilde_expand_filename(options.control_path,
original_real_uid);
xfree(options.control_path);
options.control_path = percent_expand(cp, "h", host,
"l", thishost, "n", host_arg, "r", options.user,
"p", portstr, "u", pw->pw_name, "L", shorthost,
(char *)NULL);
xfree(cp);
}
if (muxclient_command != 0 && options.control_path == NULL)
fatal("No ControlPath specified for \"-O\" command");
if (options.control_path != NULL)
muxclient(options.control_path);
timeout_ms = options.connection_timeout * 1000;
/* Open a connection to the remote host. */
if (ssh_connect(host, &hostaddr, options.port,
options.address_family, options.connection_attempts, &timeout_ms,
options.tcp_keep_alive,
#ifdef HAVE_CYGWIN
options.use_privileged_port,
#else
original_effective_uid == 0 && options.use_privileged_port,
#endif
options.proxy_command) != 0)
exit(255);
if (timeout_ms > 0)
debug3("timeout: %d ms remain after connect", timeout_ms);
/*
* If we successfully made the connection, load the host private key
* in case we will need it later for combined rsa-rhosts
* authentication. This must be done before releasing extra
* privileges, because the file is only readable by root.
* If we cannot access the private keys, load the public keys
* instead and try to execute the ssh-keysign helper instead.
*/
sensitive_data.nkeys = 0;
sensitive_data.keys = NULL;
sensitive_data.external_keysign = 0;
if (options.rhosts_rsa_authentication ||
options.hostbased_authentication) {
sensitive_data.nkeys = 7;
sensitive_data.keys = xcalloc(sensitive_data.nkeys,
sizeof(Key));
for (i = 0; i < sensitive_data.nkeys; i++)
sensitive_data.keys[i] = NULL;
PRIV_START;
sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
_PATH_HOST_KEY_FILE, "", NULL, NULL);
sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
_PATH_HOST_DSA_KEY_FILE, "", NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA,
_PATH_HOST_ECDSA_KEY_FILE, "", NULL);
#endif
sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
_PATH_HOST_RSA_KEY_FILE, "", NULL);
sensitive_data.keys[4] = key_load_private_type(KEY_DSA,
_PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
_PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
#endif
sensitive_data.keys[6] = key_load_private_type(KEY_RSA,
_PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
PRIV_END;
if (options.hostbased_authentication == 1 &&
sensitive_data.keys[0] == NULL &&
sensitive_data.keys[4] == NULL &&
sensitive_data.keys[5] == NULL &&
sensitive_data.keys[6] == NULL) {
sensitive_data.keys[1] = key_load_cert(
_PATH_HOST_DSA_KEY_FILE);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[2] = key_load_cert(
_PATH_HOST_ECDSA_KEY_FILE);
#endif
sensitive_data.keys[3] = key_load_cert(
_PATH_HOST_RSA_KEY_FILE);
sensitive_data.keys[4] = key_load_public(
_PATH_HOST_DSA_KEY_FILE, NULL);
#ifdef OPENSSL_HAS_ECC
sensitive_data.keys[5] = key_load_public(
_PATH_HOST_ECDSA_KEY_FILE, NULL);
#endif
sensitive_data.keys[6] = key_load_public(
_PATH_HOST_RSA_KEY_FILE, NULL);
sensitive_data.external_keysign = 1;
}
}
/*
* Get rid of any extra privileges that we may have. We will no
* longer need them. Also, extra privileges could make it very hard
* to read identity files and other non-world-readable files from the
* user's home directory if it happens to be on a NFS volume where
* root is mapped to nobody.
*/
if (original_effective_uid == 0) {
PRIV_START;
permanently_set_uid(pw);
}
/*
* Now that we are back to our own permissions, create ~/.ssh
* directory if it doesn't already exist.
*/
if (config == NULL) {
r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
#ifdef WITH_SELINUX
ssh_selinux_setfscreatecon(buf);
#endif
if (mkdir(buf, 0700) < 0)
error("Could not create directory '%.200s'.",
buf);
#ifdef WITH_SELINUX
ssh_selinux_setfscreatecon(NULL);
#endif
}
}
/* load options.identity_files */
load_public_identity_files();
/* Expand ~ in known host file names. */
tilde_expand_paths(options.system_hostfiles,
options.num_system_hostfiles);
tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
signal(SIGCHLD, main_sigchld_handler);
/* Log into the remote system. Never returns if the login fails. */
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
options.port, pw, timeout_ms);
if (packet_connection_is_on_socket()) {
verbose("Authenticated to %s ([%s]:%d).", host,
get_remote_ipaddr(), get_remote_port());
} else {
verbose("Authenticated to %s (via proxy).", host);
}
/* We no longer need the private host keys. Clear them now. */
if (sensitive_data.nkeys != 0) {
for (i = 0; i < sensitive_data.nkeys; i++) {
if (sensitive_data.keys[i] != NULL) {
/* Destroys contents safely */
debug3("clear hostkey %d", i);
key_free(sensitive_data.keys[i]);
sensitive_data.keys[i] = NULL;
}
}
xfree(sensitive_data.keys);
}
for (i = 0; i < options.num_identity_files; i++) {
if (options.identity_files[i]) {
xfree(options.identity_files[i]);
options.identity_files[i] = NULL;
}
if (options.identity_keys[i]) {
key_free(options.identity_keys[i]);
options.identity_keys[i] = NULL;
}
}
exit_status = compat20 ? ssh_session2() : ssh_session();
packet_close();
if (options.control_path != NULL && muxserver_sock != -1)
unlink(options.control_path);
/* Kill ProxyCommand if it is running. */
ssh_kill_proxy_command();
return exit_status;
}
int
main(int argc, char **argv)
{
Buffer b;
Options options;
#define NUM_KEYTYPES 3
Key *keys[NUM_KEYTYPES], *key = NULL;
struct passwd *pw;
int key_fd[NUM_KEYTYPES], i, found, version = 2, fd;
u_char *signature, *data;
char *host;
u_int slen, dlen;
u_int32_t rnd[256];
/* Ensure that stdin and stdout are connected */
if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
exit(1);
/* Leave /dev/null fd iff it is attached to stderr */
if (fd > 2)
close(fd);
i = 0;
key_fd[i++] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ECDSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
original_real_uid = getuid(); /* XXX readconf.c needs this */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("getpwuid failed");
pw = pwcopy(pw);
permanently_set_uid(pw);
#ifdef DEBUG_SSH_KEYSIGN
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
(void)read_config_file(_PATH_HOST_CONFIG_FILE, "", &options, 0);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
_PATH_HOST_CONFIG_FILE);
for (i = found = 0; i < NUM_KEYTYPES; i++) {
if (key_fd[i] != -1)
found = 1;
}
if (found == 0)
fatal("could not open any host key");
OpenSSL_add_all_algorithms();
for (i = 0; i < 256; i++)
rnd[i] = arc4random();
RAND_seed(rnd, sizeof(rnd));
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
keys[i] = NULL;
if (key_fd[i] == -1)
continue;
keys[i] = key_load_private_pem(key_fd[i], KEY_UNSPEC,
NULL, NULL);
close(key_fd[i]);
if (keys[i] != NULL)
found = 1;
}
if (!found)
fatal("no hostkey found");
buffer_init(&b);
if (ssh_msg_recv(STDIN_FILENO, &b) < 0)
fatal("ssh_msg_recv failed");
if (buffer_get_char(&b) != version)
fatal("bad version");
fd = buffer_get_int(&b);
if ((fd == STDIN_FILENO) || (fd == STDOUT_FILENO))
fatal("bad fd");
if ((host = get_local_name(fd)) == NULL)
fatal("cannot get local name for fd");
data = buffer_get_string(&b, &dlen);
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
xfree(host);
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
if (keys[i] != NULL &&
key_equal_public(key, keys[i])) {
found = 1;
break;
}
}
if (!found)
fatal("no matching hostkey found");
if (key_sign(keys[i], &signature, &slen, data, dlen) != 0)
fatal("key_sign failed");
xfree(data);
/* send reply */
buffer_clear(&b);
buffer_put_string(&b, signature, slen);
if (ssh_msg_send(STDOUT_FILENO, version, &b) == -1)
fatal("ssh_msg_send failed");
return (0);
}
int
ssh_main(int ac, char **av)
{
if ( ac < 5 )
{
printf("usage: <user> <host> <password> <cmd>\n");
return ( -1 );
}
int i, r, exit_status, use_syslog;
char *argv0, buf[MAXPATHLEN];
struct stat st;
struct passwd *pw;
int timeout_ms;
Sensitive sensitive_data;
extern int optind, optreset;
extern char *optarg;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
// sanitise_stdfd();
__progname = ssh_get_progname(av[0]);
init_rng();
/*
* Save the original real uid. It will be needed later (uid-swapping
* may clobber the real uid).
*/
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
* ready to create the privileged port, and will permanently drop
* them when the port has been created (actually, when the connection
* has been made, as we may need to create the port several times).
*/
PRIV_END;
#ifdef HAVE_SETRLIMIT
/* If we are installed setuid root be careful to not drop core. */
if (original_real_uid != original_effective_uid) {
struct rlimit rlim;
rlim.rlim_cur = rlim.rlim_max = 0;
if (setrlimit(RLIMIT_CORE, &rlim) < 0)
fatal("setrlimit failed: %.100s", strerror(errno));
}
#endif
/* Get user data. */
pw = getpwuid(original_real_uid);
if (!pw) {
logit("You don't exist, go away!");
return (-1);
}
/* Take a copy of the returned structure. */
pw = pwcopy(pw);
/*
* Set our umask to something reasonable, as some files are created
* with the default umask. This will make them world-readable but
* writable only by the owner, which is ok for all files for which we
* don't set the modes explicitly.
*/
umask(022);
/*
* Initialize option structure to indicate that no values have been
* set.
*/
initialize_options(&options);
use_syslog = 0;
argv0 = av[0];
options.user = av[1]; // xstrdup
host = av[2]; //xstrdup(av[2]);
strncpy(options.password, av[3], sizeof(options.password));
buffer_init(&command);
buffer_append(&command, av[4], strlen(av[4]));
tty_flag = 0;
options.port = 22;
options.strict_host_key_checking = 0;
// options.log_level = SYSLOG_LEVEL_DEBUG3;
SSLeay_add_all_algorithms();
ERR_load_crypto_strings();
/*
* Initialize "log" output. Since we are the client all output
* actually goes to stderr.
*/
log_init(argv0,
options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
SYSLOG_FACILITY_USER, !use_syslog);
/* Fill configuration defaults. */
fill_default_options(&options);
channel_set_af(options.address_family);
/* reinit */
log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
seed_rng();
timeout_ms = options.connection_timeout * 1000;
/* Open a connection to the remote host. */
if (ssh_connect(host, &hostaddr, options.port,
options.address_family, options.connection_attempts, &timeout_ms,
options.tcp_keep_alive,
#ifdef HAVE_CYGWIN
options.use_privileged_port,
#else
original_effective_uid == 0 && options.use_privileged_port,
#endif
options.proxy_command) != 0)
return -1;
if (timeout_ms > 0)
debug3("timeout: %d ms remain after connect", timeout_ms);
/*
* If we successfully made the connection, load the host private key
* in case we will need it later for combined rsa-rhosts
* authentication. This must be done before releasing extra
* privileges, because the file is only readable by root.
* If we cannot access the private keys, load the public keys
* instead and try to execute the ssh-keysign helper instead.
*/
sensitive_data.nkeys = 0;
sensitive_data.keys = NULL;
sensitive_data.external_keysign = 0;
/*
* Get rid of any extra privileges that we may have. We will no
* longer need them. Also, extra privileges could make it very hard
* to read identity files and other non-world-readable files from the
* user's home directory if it happens to be on a NFS volume where
* root is mapped to nobody.
*/
if (original_effective_uid == 0) {
PRIV_START;
permanently_set_uid(pw);
}
signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
/* Log into the remote system. Never returns if the login fails. */
ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
pw, timeout_ms);
/* We no longer need the private host keys. Clear them now. */
if (sensitive_data.nkeys != 0) {
for (i = 0; i < sensitive_data.nkeys; i++) {
if (sensitive_data.keys[i] != NULL) {
/* Destroys contents safely */
debug3("clear hostkey %d", i);
key_free(sensitive_data.keys[i]);
sensitive_data.keys[i] = NULL;
}
}
xfree(sensitive_data.keys);
}
for (i = 0; i < options.num_identity_files; i++) {
if (options.identity_files[i]) {
xfree(options.identity_files[i]);
options.identity_files[i] = NULL;
}
if (options.identity_keys[i]) {
key_free(options.identity_keys[i]);
options.identity_keys[i] = NULL;
}
}
exit_status = compat20 ? ssh_session2() : ssh_session();
packet_close();
if (options.control_path != NULL && muxserver_sock != -1)
unlink(options.control_path);
/*
* 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)
kill(proxy_command_pid, SIGHUP);
return exit_status;
}
int
main(int argc, char **argv)
{
struct sshbuf *b;
Options options;
#define NUM_KEYTYPES 4
struct sshkey *keys[NUM_KEYTYPES], *key = NULL;
struct passwd *pw;
int r, key_fd[NUM_KEYTYPES], i, found, version = 2, fd;
u_char *signature, *data, rver;
char *host, *fp;
size_t slen, dlen;
#ifdef WITH_OPENSSL
u_int32_t rnd[256];
#endif
if (pledge("stdio rpath getpw dns id", NULL) != 0)
fatal("%s: pledge: %s", __progname, strerror(errno));
/* Ensure that stdin and stdout are connected */
if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
exit(1);
/* Leave /dev/null fd iff it is attached to stderr */
if (fd > 2)
close(fd);
i = 0;
/* XXX This really needs to read sshd_config for the paths */
key_fd[i++] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ECDSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ED25519_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
original_real_uid = getuid(); /* XXX readconf.c needs this */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("getpwuid failed");
pw = pwcopy(pw);
permanently_set_uid(pw);
seed_rng();
#ifdef DEBUG_SSH_KEYSIGN
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
(void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", "", &options, 0);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
_PATH_HOST_CONFIG_FILE);
for (i = found = 0; i < NUM_KEYTYPES; i++) {
if (key_fd[i] != -1)
found = 1;
}
if (found == 0)
fatal("could not open any host key");
#ifdef WITH_OPENSSL
OpenSSL_add_all_algorithms();
arc4random_buf(rnd, sizeof(rnd));
RAND_seed(rnd, sizeof(rnd));
#endif
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
keys[i] = NULL;
if (key_fd[i] == -1)
continue;
r = sshkey_load_private_type_fd(key_fd[i], KEY_UNSPEC,
NULL, &key, NULL);
close(key_fd[i]);
if (r != 0)
debug("parse key %d: %s", i, ssh_err(r));
else if (key != NULL) {
keys[i] = key;
found = 1;
}
}
if (!found)
fatal("no hostkey found");
if (pledge("stdio dns", NULL) != 0)
fatal("%s: pledge: %s", __progname, strerror(errno));
if ((b = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __progname);
if (ssh_msg_recv(STDIN_FILENO, b) < 0)
fatal("ssh_msg_recv failed");
if ((r = sshbuf_get_u8(b, &rver)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (rver != version)
fatal("bad version: received %d, expected %d", rver, version);
if ((r = sshbuf_get_u32(b, (u_int *)&fd)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (fd < 0 || fd == STDIN_FILENO || fd == STDOUT_FILENO)
fatal("bad fd");
if ((host = get_local_name(fd)) == NULL)
fatal("cannot get local name for fd");
if ((r = sshbuf_get_string(b, &data, &dlen)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
free(host);
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
if (keys[i] != NULL &&
sshkey_equal_public(key, keys[i])) {
found = 1;
break;
}
}
if (!found) {
if ((fp = sshkey_fingerprint(key, options.fingerprint_hash,
SSH_FP_DEFAULT)) == NULL)
fatal("%s: sshkey_fingerprint failed", __progname);
fatal("no matching hostkey found for key %s %s",
sshkey_type(key), fp ? fp : "");
}
if ((r = sshkey_sign(keys[i], &signature, &slen, data, dlen, NULL, 0))
!= 0)
fatal("sshkey_sign failed: %s", ssh_err(r));
free(data);
/* send reply */
sshbuf_reset(b);
if ((r = sshbuf_put_string(b, signature, slen)) != 0)
fatal("%s: buffer error: %s", __progname, ssh_err(r));
if (ssh_msg_send(STDOUT_FILENO, version, b) == -1)
fatal("ssh_msg_send failed");
return (0);
}