* called by a name other than "ssh" or "Secure Shell".
*
* SSH2 implementation:
+ * Privilege Separation:
*
- * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
+ * Copyright (c) 2002 Niels Provos. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.230 2002/03/18 01:12:14 provos Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.288 2004/03/03 06:47:52 markus 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"
#include "dispatch.h"
#include "channels.h"
#include "session.h"
+#include "monitor_mm.h"
+#include "monitor.h"
+#include "monitor_wrap.h"
+#include "monitor_fdpass.h"
#ifdef LIBWRAP
#include <tcpd.h>
* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
* Default value is AF_UNSPEC means both IPv4 and IPv6.
*/
-#ifdef IPV4_DEFAULT
-int IPv4or6 = AF_INET;
-#else
int IPv4or6 = AF_UNSPEC;
-#endif
/*
* Debug mode flag. This can be set on the command line. If debug
/* same for ssh2 */
u_char *session_id2 = NULL;
-int session_id2_len = 0;
+u_int session_id2_len = 0;
/* record remote hostname or ip */
u_int utmp_len = MAXHOSTNAMELEN;
int *startup_pipes = NULL;
int startup_pipe; /* in child */
+/* variables used for privilege separation */
+int use_privsep;
+struct monitor *pmonitor = NULL;
+
+/* message to be displayed after login */
+Buffer loginmsg;
+
+/* global authentication context */
+Authctxt *the_authctxt = NULL;
+
/* Prototypes for various functions defined later in this file. */
void destroy_sensitive_data(void);
+void demote_sensitive_data(void);
static void do_ssh1_kex(void);
static void do_ssh2_kex(void);
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)
static void
sighup_restart(void)
{
- log("Received SIGHUP; restarting.");
+ logit("Received SIGHUP; restarting.");
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));
+ logit("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();
+ if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
+ kill(pmonitor->m_pid, SIGALRM);
/* Log error and exit. */
- fatal("Timeout before authentication for %s.", get_remote_ipaddr());
+ 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;
snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
server_version_string = xstrdup(buf);
- if (client_version_string == NULL) {
- /* Send our protocol version identification. */
- 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();
- }
+ /* Send our protocol version identification. */
+ if (atomicio(vwrite, sock_out, server_version_string,
+ strlen(server_version_string))
+ != strlen(server_version_string)) {
+ logit("Could not write ident string to %s", get_remote_ipaddr());
+ cleanup_exit(255);
+ }
- /* Read other side's version identification. */
- memset(buf, 0, sizeof(buf));
- for (i = 0; i < sizeof(buf) - 1; i++) {
- if (atomicio(read, sock_in, &buf[i], 1) != 1) {
- log("Did not receive identification string from %s",
- get_remote_ipaddr());
- fatal_cleanup();
- }
- if (buf[i] == '\r') {
- buf[i] = 0;
- /* Kludge for F-Secure Macintosh < 1.0.2 */
- if (i == 12 &&
- strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
- break;
- continue;
- }
- if (buf[i] == '\n') {
- buf[i] = 0;
+ /* 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) {
+ logit("Did not receive identification string from %s",
+ get_remote_ipaddr());
+ cleanup_exit(255);
+ }
+ if (buf[i] == '\r') {
+ buf[i] = 0;
+ /* Kludge for F-Secure Macintosh < 1.0.2 */
+ if (i == 12 &&
+ strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
break;
- }
+ continue;
+ }
+ if (buf[i] == '\n') {
+ buf[i] = 0;
+ break;
}
- buf[sizeof(buf) - 1] = 0;
- client_version_string = xstrdup(buf);
}
+ buf[sizeof(buf) - 1] = 0;
+ client_version_string = xstrdup(buf);
/*
* Check that the versions match. In future this might accept
if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
&remote_major, &remote_minor, remote_version) != 3) {
s = "Protocol mismatch.\n";
- (void) atomicio(write, sock_out, s, strlen(s));
+ (void) atomicio(vwrite, sock_out, s, strlen(s));
close(sock_in);
close(sock_out);
- log("Bad protocol version identification '%.100s' from %s",
+ logit("Bad protocol version identification '%.100s' from %s",
client_version_string, get_remote_ipaddr());
- fatal_cleanup();
+ cleanup_exit(255);
}
debug("Client protocol version %d.%d; client software version %.100s",
remote_major, remote_minor, remote_version);
compat_datafellows(remote_version);
+ if (datafellows & SSH_BUG_PROBE) {
+ logit("probed from %s with %s. Don't panic.",
+ get_remote_ipaddr(), client_version_string);
+ cleanup_exit(255);
+ }
+
if (datafellows & SSH_BUG_SCANNER) {
- log("scanned from %s with %s. Don't panic.",
+ logit("scanned from %s with %s. Don't panic.",
get_remote_ipaddr(), client_version_string);
- fatal_cleanup();
+ cleanup_exit(255);
}
mismatch = 0;
if (mismatch) {
s = "Protocol major versions differ.\n";
- (void) atomicio(write, sock_out, s, strlen(s));
+ (void) atomicio(vwrite, sock_out, s, strlen(s));
close(sock_in);
close(sock_out);
- log("Protocol major versions differ for %s: %.200s vs. %.200s",
+ logit("Protocol major versions differ for %s: %.200s vs. %.200s",
get_remote_ipaddr(),
server_version_string, client_version_string);
- fatal_cleanup();
+ cleanup_exit(255);
}
}
-
/* Destroy the host and server keys. They will no longer be needed. */
void
destroy_sensitive_data(void)
memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
}
+/* Demote private to public keys for network child */
+void
+demote_sensitive_data(void)
+{
+ Key *tmp;
+ int i;
+
+ if (sensitive_data.server_key) {
+ tmp = key_demote(sensitive_data.server_key);
+ key_free(sensitive_data.server_key);
+ sensitive_data.server_key = tmp;
+ }
+
+ for (i = 0; i < options.num_host_key_files; i++) {
+ if (sensitive_data.host_keys[i]) {
+ tmp = key_demote(sensitive_data.host_keys[i]);
+ key_free(sensitive_data.host_keys[i]);
+ sensitive_data.host_keys[i] = tmp;
+ if (tmp->type == KEY_RSA1)
+ sensitive_data.ssh1_host_key = tmp;
+ }
+ }
+
+ /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
+}
+
+static void
+privsep_preauth_child(void)
+{
+ 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++)
+ rnd[i] = arc4random();
+ RAND_seed(rnd, sizeof(rnd));
+
+ /* 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, too heavy after chroot */
+ do_setusercontext(pw);
+#else
+ gidset[0] = pw->pw_gid;
+ if (setgroups(1, gidset) < 0)
+ fatal("setgroups: %.100s", strerror(errno));
+ permanently_set_uid(pw);
+#endif
+}
+
+static int
+privsep_preauth(Authctxt *authctxt)
+{
+ int status;
+ pid_t pid;
+
+ /* 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) {
+ debug2("Network child is on pid %ld", (long)pid);
+
+ close(pmonitor->m_recvfd);
+ pmonitor->m_pid = pid;
+ monitor_child_preauth(authctxt, 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;
+ return (1);
+ } else {
+ /* child */
+
+ close(pmonitor->m_sendfd);
+
+ /* Demote the child */
+ if (getuid() == 0 || geteuid() == 0)
+ privsep_preauth_child();
+ setproctitle("%s", "[net]");
+ }
+ return (0);
+}
+
+static void
+privsep_postauth(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(pmonitor);
+ use_privsep = 0;
+ return;
+ }
+
+ /* Authentication complete */
+ alarm(0);
+ if (startup_pipe != -1) {
+ close(startup_pipe);
+ startup_pipe = -1;
+ }
+
+ /* New socket pair */
+ monitor_reinit(pmonitor);
+
+ pmonitor->m_pid = fork();
+ if (pmonitor->m_pid == -1)
+ fatal("fork of unprivileged child failed");
+ else if (pmonitor->m_pid != 0) {
+ debug2("User child is on pid %ld", (long)pmonitor->m_pid);
+ close(pmonitor->m_recvfd);
+ monitor_child_postauth(pmonitor);
+
+ /* NEVERREACHED */
+ exit(0);
+ }
+
+ close(pmonitor->m_sendfd);
+
+ /* Demote the private keys to public keys. */
+ demote_sensitive_data();
+
+ /* Drop privileges */
+ do_setusercontext(authctxt->pw);
+
+ /* It is safe now to apply the key state */
+ monitor_apply_keystate(pmonitor);
+}
+
static char *
list_hostkey_types(void)
{
Buffer b;
- char *p;
+ const char *p;
+ char *ret;
int i;
buffer_init(&b);
}
}
buffer_append(&b, "\0", 1);
- p = xstrdup(buffer_ptr(&b));
+ ret = xstrdup(buffer_ptr(&b));
buffer_free(&b);
- debug("list_hostkey_types: %s", p);
- return p;
+ debug("list_hostkey_types: %s", ret);
+ return ret;
}
-static Key *
+Key *
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)
return NULL;
}
+Key *
+get_hostkey_by_index(int ind)
+{
+ if (ind < 0 || ind >= options.num_host_key_files)
+ return (NULL);
+ return (sensitive_data.host_keys[ind]);
+}
+
+int
+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);
+ }
+ return (-1);
+}
+
/*
* returns 1 if connection should be dropped, 0 otherwise.
* dropping starts at connection #max_startups_begin with a probability
static void
usage(void)
{
- fprintf(stderr, "sshd version %s\n", SSH_VERSION);
+ fprintf(stderr, "sshd version %s, %s\n",
+ SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
fprintf(stderr, "Usage: %s [options]\n", __progname);
fprintf(stderr, "Options:\n");
fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
const char *remote_ip;
int remote_port;
FILE *f;
- struct linger linger;
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ char *line;
int listen_sock, maxfd;
int startup_p[2];
int startups = 0;
- Authctxt *authctxt;
Key *key;
+ Authctxt *authctxt;
int ret, key_used = 0;
- __progname = get_progname(av[0]);
+#ifdef HAVE_SECUREWARE
+ (void)set_auth_parameters(ac, av);
+#endif
+ __progname = ssh_get_progname(av[0]);
init_rng();
- /* Save argv. */
+ /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
saved_argc = ac;
- saved_argv = av;
+ saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
+ for (i = 0; i < ac; i++)
+ saved_argv[i] = xstrdup(av[i]);
+ saved_argv[i] = NULL;
+
+#ifndef HAVE_SETPROCTITLE
+ /* Prepare for later setproctitle emulation */
+ compat_init_setproctitle(ac, av);
+ av = saved_argv;
+#endif
/* Initialize configuration options to their default values. */
initialize_server_options(&options);
/* Parse command-line arguments. */
- while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46")) != -1) {
+ while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqtQ46")) != -1) {
switch (opt) {
case '4':
IPv4or6 = AF_INET;
config_file_name = optarg;
break;
case 'd':
- if (0 == debug_flag) {
+ if (debug_flag == 0) {
debug_flag = 1;
options.log_level = SYSLOG_LEVEL_DEBUG1;
- } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
+ } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
options.log_level++;
- } else {
- fprintf(stderr, "Too high debugging level.\n");
- exit(1);
- }
break;
case 'D':
no_daemon_flag = 1;
}
options.host_key_files[options.num_host_key_files++] = optarg;
break;
- case 'V':
- client_version_string = optarg;
- /* only makes sense with inetd_flag, i.e. no listen() */
- inetd_flag = 1;
- break;
case 't':
test_flag = 1;
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,
+ line = xstrdup(optarg);
+ if (process_server_config_line(&options, line,
"command-line", 0) != 0)
exit(1);
+ xfree(line);
break;
case '?':
default:
SYSLOG_LEVEL_INFO : options.log_level,
options.log_facility == SYSLOG_FACILITY_NOT_SET ?
SYSLOG_FACILITY_AUTH : options.log_facility,
- !inetd_flag);
+ log_stderr || !inetd_flag);
-#ifdef _CRAY
+#ifdef _AIX
+ /*
+ * Unset KRB5CCNAME, otherwise the user's session may inherit it from
+ * root's environment
+ */
+ unsetenv("KRB5CCNAME");
+#endif /* _AIX */
+#ifdef _UNICOS
/* 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;
key_type(key));
}
if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
- log("Disabling protocol version 1. Could not load host key");
+ logit("Disabling protocol version 1. Could not load host key");
options.protocol &= ~SSH_PROTO_1;
}
if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
- log("Disabling protocol version 2. Could not load host key");
+ logit("Disabling protocol version 2. Could not load host key");
options.protocol &= ~SSH_PROTO_2;
}
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
- log("sshd: no hostkeys available -- exiting.");
+ logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
* 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("%s must be owned by root and not group or "
+ "world-writable.", _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)
continue;
}
/* Create socket for listening. */
- listen_sock = socket(ai->ai_family, SOCK_STREAM, 0);
+ listen_sock = socket(ai->ai_family, ai->ai_socktype,
+ ai->ai_protocol);
if (listen_sock < 0) {
/* kernel may not support ipv6 */
verbose("socket: %.100s", strerror(errno));
continue;
}
/*
- * Set socket options. We try to make the port
- * reusable and have it close as fast as possible
- * without waiting in unnecessary wait states on
- * close.
+ * Set socket options.
+ * Allow local port reuse in TIME_WAIT.
*/
- setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
- &on, sizeof(on));
- linger.l_onoff = 1;
- linger.l_linger = 5;
- setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
- &linger, sizeof(linger));
+ if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
+ &on, sizeof(on)) == -1)
+ error("setsockopt SO_REUSEADDR: %s", strerror(errno));
debug("Bind to port %s on %s.", strport, ntop);
num_listen_socks++;
/* Start listening on the port. */
- log("Server listening on %s port %s.", ntop, strport);
- if (listen(listen_sock, 5) < 0)
+ logit("Server listening on %s port %s.", ntop, strport);
+ if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
fatal("listen: %.100s", strerror(errno));
}
* overwrite any old pid in the file.
*/
f = fopen(options.pid_file, "wb");
- if (f) {
- fprintf(f, "%u\n", (u_int) getpid());
+ if (f == NULL) {
+ error("Couldn't create pid file \"%s\": %s",
+ options.pid_file, strerror(errno));
+ } else {
+ fprintf(f, "%ld\n", (long) getpid());
fclose(f);
}
}
if (ret < 0 && errno != EINTR)
error("select: %.100s", strerror(errno));
if (received_sigterm) {
- log("Received signal %d; terminating.",
+ logit("Received signal %d; terminating.",
(int) received_sigterm);
close_listen_socks();
unlink(options.pid_file);
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. */
+ setproctitle("%s", "[accepted]");
+
+ /*
+ * 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 !defined(SSHD_ACQUIRES_CTTY)
+ /*
+ * If setsid is called, on some platforms sshd will later acquire a
+ * controlling terminal which will result in "could not set
+ * controlling tty" errors.
+ */
+ if (!debug_flag && !inetd_flag && setsid() < 0)
+ error("setsid: %.100s", strerror(errno));
+#endif
/*
* Disable the key regeneration alarm. We will not regenerate the
signal(SIGCHLD, SIG_DFL);
signal(SIGINT, SIG_DFL);
- /*
- * Set socket options for the connection. We want the socket to
- * close as fast as possible without waiting for anything. If the
- * connection is not a socket, these will do nothing.
- */
- /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */
- linger.l_onoff = 1;
- linger.l_linger = 5;
- setsockopt(sock_in, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
-
- /* Set keepalives if requested. */
- if (options.keepalives &&
+ /* Set SO_KEEPALIVE if requested. */
+ if (options.tcp_keep_alive &&
setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
sizeof(on)) < 0)
error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
alarm(options.login_grace_time);
sshd_exchange_identification(sock_in, sock_out);
- /*
- * Check that the connection comes from a privileged port.
- * Rhosts-Authentication only makes sense from priviledged
- * 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.
- */
- if (options.rhosts_authentication &&
- (remote_port >= IPPORT_RESERVED ||
- remote_port < IPPORT_RESERVED / 2)) {
- debug("Rhosts Authentication disabled, "
- "originating port %d not trusted.", remote_port);
- options.rhosts_authentication = 0;
- }
-#if defined(KRB4) && !defined(KRB5)
- if (!packet_connection_is_ipv4() &&
- options.kerberos_authentication) {
- debug("Kerberos Authentication disabled, only available for IPv4.");
- options.kerberos_authentication = 0;
- }
-#endif /* KRB4 && !KRB5 */
-#ifdef AFS
- /* If machine has AFS, set process authentication group. */
- if (k_hasafs()) {
- k_setpag();
- k_unlog();
- }
-#endif /* AFS */
packet_set_nonblocking();
+ /* prepare buffers to collect authentication messages */
+ buffer_init(&loginmsg);
+
+ /* allocate authentication context */
+ authctxt = xmalloc(sizeof(*authctxt));
+ memset(authctxt, 0, sizeof(*authctxt));
+
+ /* XXX global for cleanup, access from other modules */
+ the_authctxt = authctxt;
+
+ if (use_privsep)
+ if (privsep_preauth(authctxt) == 1)
+ goto authenticated;
+
/* perform the key exchange */
/* authenticate user and start session */
if (compat20) {
do_ssh2_kex();
- authctxt = do_authentication2();
+ do_authentication2(authctxt);
} else {
do_ssh1_kex();
- authctxt = do_authentication();
+ do_authentication(authctxt);
+ }
+ /*
+ * If we use privilege separation, the unprivileged child transfers
+ * the current keystate and exits
+ */
+ if (use_privsep) {
+ mm_send_keystate(pmonitor);
+ exit(0);
+ }
+
+ authenticated:
+ /*
+ * In privilege separation, we fork another child and prepare
+ * file descriptor passing.
+ */
+ if (use_privsep) {
+ privsep_postauth(authctxt);
+ /* the monitor process [priv] will not return */
+ if (!compat20)
+ destroy_sensitive_data();
}
- /* Perform session preparation. */
+ /* Start session. */
do_authenticated(authctxt);
/* The connection has been terminated. */
verbose("Closing connection to %.100s", remote_ip);
#ifdef USE_PAM
- finish_pam();
+ if (options.use_pam)
+ finish_pam();
#endif /* USE_PAM */
packet_close();
+
+ if (use_privsep)
+ mm_terminate();
+
exit(0);
}
* Decrypt session_key_int using our private server key and private host key
* (key with larger modulus first).
*/
-static int
+int
ssh1_session_key(BIGNUM *session_key_int)
{
int rsafail = 0;
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;
}
/*
/* Declare supported authentication types. */
auth_mask = 0;
- if (options.rhosts_authentication)
- auth_mask |= 1 << SSH_AUTH_RHOSTS;
if (options.rhosts_rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
if (options.rsa_authentication)
auth_mask |= 1 << SSH_AUTH_RSA;
-#if defined(KRB4) || defined(KRB5)
- if (options.kerberos_authentication)
- auth_mask |= 1 << SSH_AUTH_KERBEROS;
-#endif
-#if defined(AFS) || defined(KRB5)
- if (options.kerberos_tgt_passing)
- auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
-#endif
-#ifdef AFS
- if (options.afs_token_passing)
- auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
-#endif
if (options.challenge_response_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
if (options.password_authentication)
packet_check_eom();
/* Decrypt session_key_int using host/server keys */
- rsafail = ssh1_session_key(session_key_int);
+ rsafail = PRIVSEP(ssh1_session_key(session_key_int));
+
/*
* Extract session key from the decrypted integer. The key is in the
* least significant 256 bits of the integer; the first byte of the
u_char *buf = xmalloc(bytes);
MD5_CTX md;
- log("do_connection: generating a fake encryption key");
+ logit("do_connection: generating a fake encryption key");
BN_bn2bin(session_key_int, buf);
MD5_Init(&md);
MD5_Update(&md, buf, bytes);
for (i = 0; i < 16; i++)
session_id[i] = session_key[i] ^ session_key[i + 16];
}
- /* Destroy the private and public keys. They will no longer be needed. */
+ /* Destroy the private and public keys. No longer. */
destroy_sensitive_data();
+ if (use_privsep)
+ mm_ssh1_session_id(session_id);
+
/* Destroy the decrypted integer. It is no longer needed. */
BN_clear_free(session_key_int);
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 */
kex = kex_setup(myproposal);
+ kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
+ kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
kex->server = 1;
kex->client_version_string=client_version_string;
kex->server_version_string=server_version_string;
kex->load_host_key=&get_hostkey_by_type;
+ kex->host_key_index=&get_hostkey_index;
xxx_kex = kex;
#endif
debug("KEX done");
}
+
+/* server specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+ if (the_authctxt)
+ do_cleanup(the_authctxt);
+ _exit(i);
+}
andersk / openssh.git / blobdiff