*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.234 2002/03/19 10:49:35 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.257 2002/07/23 16:03:10 stevesk Exp $");
#include <openssl/dh.h>
#include <openssl/bn.h>
#include <openssl/md5.h>
#include <openssl/rand.h>
+#ifdef HAVE_SECUREWARE
+#include <sys/security.h>
+#include <prot.h>
+#endif
#include "ssh.h"
#include "ssh1.h"
int startup_pipe; /* in child */
/* variables used for privilege separation */
-extern struct monitor *monitor;
+extern struct monitor *pmonitor;
extern int use_privsep;
/* Prototypes for various functions defined later in this file. */
close_listen_socks(void)
{
int i;
+
for (i = 0; i < num_listen_socks; i++)
close(listen_socks[i]);
num_listen_socks = -1;
close_startup_pipes(void)
{
int i;
+
if (startup_pipes)
for (i = 0; i < options.max_startups; i++)
if (startup_pipes[i] != -1)
close_listen_socks();
close_startup_pipes();
execv(saved_argv[0], saved_argv);
- log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno));
+ log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
+ strerror(errno));
exit(1);
}
main_sigchld_handler(int sig)
{
int save_errno = errno;
+ pid_t pid;
int status;
- while (waitpid(-1, &status, WNOHANG) > 0)
+ while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
+ (pid < 0 && errno == EINTR))
;
signal(SIGCHLD, main_sigchld_handler);
{
/* XXX no idea how fix this signal handler */
- /* Close the connection. */
- packet_close();
-
/* Log error and exit. */
fatal("Timeout before authentication for %s.", get_remote_ipaddr());
}
static void
generate_ephemeral_server_key(void)
{
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
int i;
verbose("Generating %s%d bit RSA key.",
for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
if (i % 4 == 0)
- rand = arc4random();
- sensitive_data.ssh1_cookie[i] = rand & 0xff;
- rand >>= 8;
+ rnd = arc4random();
+ sensitive_data.ssh1_cookie[i] = rnd & 0xff;
+ rnd >>= 8;
}
arc4random_stir();
}
key_regeneration_alarm(int sig)
{
int save_errno = errno;
+
signal(SIGALRM, SIG_DFL);
errno = save_errno;
key_do_regen = 1;
if (client_version_string == NULL) {
/* Send our protocol version identification. */
- if (atomicio(write, sock_out, server_version_string, strlen(server_version_string))
+ if (atomicio(write, sock_out, server_version_string,
+ strlen(server_version_string))
!= strlen(server_version_string)) {
log("Could not write ident string to %s", get_remote_ipaddr());
fatal_cleanup();
}
- /* Read other side's version identification. */
+ /* Read other sides version identification. */
memset(buf, 0, sizeof(buf));
for (i = 0; i < sizeof(buf) - 1; i++) {
if (atomicio(read, sock_in, &buf[i], 1) != 1) {
}
}
-
/* Destroy the host and server keys. They will no longer be needed. */
void
destroy_sensitive_data(void)
static void
privsep_preauth_child(void)
{
- u_int32_t rand[256];
+ u_int32_t rnd[256];
+ gid_t gidset[1];
+ 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));
+ rnd[i] = arc4random();
+ RAND_seed(rnd, sizeof(rnd));
/* Demote the private keys to public keys. */
demote_sensitive_data();
- /* Change our root directory*/
+ 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(/)");
+ fatal("chdir(\"/\"): %s", strerror(errno));
/* Drop our privileges */
- setegid(options.unprivileged_group);
- setgid(options.unprivileged_group);
- seteuid(options.unprivileged_user);
- setuid(options.unprivileged_user);
+ 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
}
-static void
-privsep_postauth(Authctxt *authctxt, pid_t pid)
+static Authctxt *
+privsep_preauth(void)
{
- extern Authctxt *x_authctxt;
+ Authctxt *authctxt = NULL;
int status;
+ pid_t pid;
- /* Wait for the child's exit status */
- waitpid(pid, &status, 0);
+ /* Set up unprivileged child process to deal with network data */
+ pmonitor = monitor_init();
+ /* Store a pointer to the kex for later rekeying */
+ pmonitor->m_pkex = &xxx_kex;
+
+ pid = fork();
+ if (pid == -1) {
+ fatal("fork of unprivileged child failed");
+ } else if (pid != 0) {
+ fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
+
+ debug2("Network child is on pid %ld", (long)pid);
+
+ close(pmonitor->m_recvfd);
+ authctxt = monitor_child_preauth(pmonitor);
+ close(pmonitor->m_sendfd);
+
+ /* Sync memory */
+ monitor_sync(pmonitor);
+
+ /* Wait for the child's exit status */
+ while (waitpid(pid, &status, 0) < 0)
+ if (errno != EINTR)
+ break;
+
+ /* Reinstall, since the child has finished */
+ fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
+
+ return (authctxt);
+ } else {
+ /* child */
+
+ close(pmonitor->m_sendfd);
+
+ /* Demote the child */
+ if (getuid() == 0 || geteuid() == 0)
+ privsep_preauth_child();
+ setproctitle("%s", "[net]");
+ }
+ return (NULL);
+}
+
+static void
+privsep_postauth(Authctxt *authctxt)
+{
+ extern Authctxt *x_authctxt;
/* XXX - Remote port forwarding */
x_authctxt = authctxt;
+#ifdef DISABLE_FD_PASSING
+ if (1) {
+#else
if (authctxt->pw->pw_uid == 0 || options.use_login) {
+#endif
/* File descriptor passing is broken or root login */
- monitor_apply_keystate(monitor);
+ monitor_apply_keystate(pmonitor);
use_privsep = 0;
return;
}
}
/* New socket pair */
- monitor_reinit(monitor);
+ monitor_reinit(pmonitor);
- monitor->m_pid = fork();
- if (monitor->m_pid == -1)
+ pmonitor->m_pid = fork();
+ if (pmonitor->m_pid == -1)
fatal("fork of unprivileged child failed");
- else if (monitor->m_pid != 0) {
- debug2("User child is on pid %d", pid);
- close(monitor->m_recvfd);
- monitor_child_postauth(monitor);
+ else if (pmonitor->m_pid != 0) {
+ fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
+
+ debug2("User child is on pid %ld", (long)pmonitor->m_pid);
+ close(pmonitor->m_recvfd);
+ monitor_child_postauth(pmonitor);
/* NEVERREACHED */
exit(0);
}
- close(monitor->m_sendfd);
+ close(pmonitor->m_sendfd);
/* Demote the private keys to public keys. */
demote_sensitive_data();
do_setusercontext(authctxt->pw);
/* It is safe now to apply the key state */
- monitor_apply_keystate(monitor);
+ monitor_apply_keystate(pmonitor);
}
-
static char *
list_hostkey_types(void)
{
get_hostkey_by_type(int type)
{
int i;
+
for (i = 0; i < options.num_host_key_files; i++) {
Key *key = sensitive_data.host_keys[i];
if (key != NULL && key->type == type)
get_hostkey_index(Key *key)
{
int i;
+
for (i = 0; i < options.num_host_key_files; i++) {
if (key == sensitive_data.host_keys[i])
return (i);
Key *key;
int ret, key_used = 0;
+#ifdef HAVE_SECUREWARE
+ (void)set_auth_parameters(ac, av);
+#endif
__progname = get_progname(av[0]);
init_rng();
break;
case 'u':
utmp_len = atoi(optarg);
+ if (utmp_len > MAXHOSTNAMELEN) {
+ fprintf(stderr, "Invalid utmp length.\n");
+ exit(1);
+ }
break;
case 'o':
if (process_server_config_line(&options, optarg,
SYSLOG_FACILITY_AUTH : options.log_facility,
!inetd_flag);
-#ifdef _CRAY
+#if defined(_CRAY) && !defined(_CRAYSV2)
/* Cray can define user privs drop all prives now!
* Not needed on PRIV_SU systems!
*/
debug("sshd version %.100s", SSH_VERSION);
/* load private host keys */
- sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*));
+ sensitive_data.host_keys = xmalloc(options.num_host_key_files *
+ sizeof(Key *));
for (i = 0; i < options.num_host_key_files; i++)
sensitive_data.host_keys[i] = NULL;
sensitive_data.server_key = NULL;
* hate software patents. I dont know if this can go? Niels
*/
if (options.server_key_bits >
- BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED &&
- options.server_key_bits <
- BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
+ SSH_KEY_BITS_RESERVED && options.server_key_bits <
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
+ SSH_KEY_BITS_RESERVED) {
options.server_key_bits =
- BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED;
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
+ SSH_KEY_BITS_RESERVED;
debug("Forcing server key to %d bits to make it differ from host key.",
options.server_key_bits);
}
}
+ if (use_privsep) {
+ struct passwd *pw;
+ struct stat st;
+
+ if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
+ fatal("Privilege separation user %s does not exist",
+ SSH_PRIVSEP_USER);
+ if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
+ (S_ISDIR(st.st_mode) == 0))
+ fatal("Missing privilege separation directory: %s",
+ _PATH_PRIVSEP_CHROOT_DIR);
+
+#ifdef HAVE_CYGWIN
+ if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
+ (st.st_uid != getuid () ||
+ (st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
+#else
+ if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
+#endif
+ fatal("Bad owner or mode for %s",
+ _PATH_PRIVSEP_CHROOT_DIR);
+ }
+
/* Configuration looks good, so exit if in test mode. */
if (test_flag)
exit(0);
-#ifdef HAVE_SCO_PROTECTED_PW
- (void) set_auth_parameters(ac, av);
-#endif
+ /*
+ * Clear out any supplemental groups we may have inherited. This
+ * prevents inadvertent creation of files with bad modes (in the
+ * portable version at least, it's certainly possible for PAM
+ * to create a file, and we can't control the code in every
+ * module which might be used).
+ */
+ if (setgroups(0, NULL) < 0)
+ debug("setgroups() failed: %.200s", strerror(errno));
/* Initialize the log (it is reinitialized below in case we forked). */
if (debug_flag && !inetd_flag)
*/
f = fopen(options.pid_file, "wb");
if (f) {
- fprintf(f, "%u\n", (u_int) getpid());
+ fprintf(f, "%ld\n", (long) getpid());
fclose(f);
}
}
if (pid < 0)
error("fork: %.100s", strerror(errno));
else
- debug("Forked child %d.", pid);
+ debug("Forked child %ld.", (long)pid);
close(startup_p[1]);
/* This is the child processing a new connection. */
+ /*
+ * Create a new session and process group since the 4.4BSD
+ * setlogin() affects the entire process group. We don't
+ * want the child to be able to affect the parent.
+ */
+#if 0
+ /* XXX: this breaks Solaris */
+ if (!debug_flag && !inetd_flag && setsid() < 0)
+ error("setsid: %.100s", strerror(errno));
+#endif
+
/*
* Disable the key regeneration alarm. We will not regenerate the
* key since we are no longer in a position to give it to anyone. We
sshd_exchange_identification(sock_in, sock_out);
/*
* Check that the connection comes from a privileged port.
- * Rhosts-Authentication only makes sense from priviledged
+ * Rhosts-Authentication only makes sense from privileged
* programs. Of course, if the intruder has root access on his local
* machine, he can connect from any port. So do not use these
* authentication methods from machines that you do not trust.
packet_set_nonblocking();
- if (!use_privsep)
- goto skip_privilegeseparation;
-
- /* Set up unprivileged child process to deal with network data */
- monitor = monitor_init();
- /* Store a pointer to the kex for later rekeying */
- monitor->m_pkex = &xxx_kex;
-
- pid = fork();
- if (pid == -1)
- fatal("fork of unprivileged child failed");
- else if (pid != 0) {
- debug2("Network child is on pid %d", pid);
-
- close(monitor->m_recvfd);
- authctxt = monitor_child_preauth(monitor);
- close(monitor->m_sendfd);
-
- /* Sync memory */
- monitor_sync(monitor);
- goto authenticated;
- } else {
- close(monitor->m_sendfd);
-
- /* Demote the child */
- if (getuid() == 0 || geteuid() == 0)
- privsep_preauth_child();
- }
-
- skip_privilegeseparation:
+ if (use_privsep)
+ if ((authctxt = privsep_preauth()) != NULL)
+ goto authenticated;
/* perform the key exchange */
/* authenticate user and start session */
do_ssh1_kex();
authctxt = do_authentication();
}
- if (use_privsep)
- mm_send_keystate(monitor);
-
- /* If we use privilege separation, the unprivileged child exits */
- if (use_privsep)
+ /*
+ * If we use privilege separation, the unprivileged child transfers
+ * the current keystate and exits
+ */
+ if (use_privsep) {
+ mm_send_keystate(pmonitor);
exit(0);
+ }
authenticated:
/*
* file descriptor passing.
*/
if (use_privsep) {
- privsep_postauth(authctxt, pid);
+ privsep_postauth(authctxt);
+ /* the monitor process [priv] will not return */
if (!compat20)
destroy_sensitive_data();
}
u_char session_key[SSH_SESSION_KEY_LENGTH];
u_char cookie[8];
u_int cipher_type, auth_mask, protocol_flags;
- u_int32_t rand = 0;
+ u_int32_t rnd = 0;
/*
* Generate check bytes that the client must send back in the user
*/
for (i = 0; i < 8; i++) {
if (i % 4 == 0)
- rand = arc4random();
- cookie[i] = rand & 0xff;
- rand >>= 8;
+ rnd = arc4random();
+ cookie[i] = rnd & 0xff;
+ rnd >>= 8;
}
/*
debug("Received session key; encryption turned on.");
- /* Send an acknowledgement packet. Note that this packet is sent encrypted. */
+ /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
packet_start(SSH_SMSG_SUCCESS);
packet_send();
packet_write_wait();
myproposal[PROPOSAL_MAC_ALGS_CTOS] =
myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
}
+ if (!options.compression) {
+ myproposal[PROPOSAL_COMP_ALGS_CTOS] =
+ myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
+ }
myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
/* start key exchange */