* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
- * Created: Fri Mar 17 17:09:28 1995 ylo
- * This program is the ssh daemon. It listens for connections from clients, and
- * performs authentication, executes use commands or shell, and forwards
+ * This program is the ssh daemon. It listens for connections from clients,
+ * and performs authentication, executes use commands or shell, and forwards
* information to/from the application to the user client over an encrypted
- * connection. This can also handle forwarding of X11, TCP/IP, and authentication
- * agent connections.
+ * connection. This can also handle forwarding of X11, TCP/IP, and
+ * authentication agent connections.
*
- * SSH2 implementation,
- * Copyright (c) 2000 Markus Friedl. All rights reserved.
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose. Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ *
+ * SSH2 implementation:
+ * Privilege Separation:
+ *
+ * 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
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.99 2000/04/07 09:17:39 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.276 2003/08/28 12:54:34 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 "ssh2.h"
#include "xmalloc.h"
#include "rsa.h"
-#include "ssh.h"
-#include "pty.h"
+#include "sshpty.h"
#include "packet.h"
-#include "cipher.h"
#include "mpaux.h"
+#include "log.h"
#include "servconf.h"
#include "uidswap.h"
#include "compat.h"
#include "buffer.h"
-
-#include "ssh2.h"
-#ifdef HAVE_OPENSSL
-# include <openssl/dh.h>
-# include <openssl/bn.h>
-# include <openssl/hmac.h>
-# include <openssl/dsa.h>
-# include <openssl/rsa.h>
-#endif
-#ifdef HAVE_SSL
-# include <ssl/dh.h>
-# include <ssl/bn.h>
-# include <ssl/hmac.h>
-# include <ssl/dsa.h>
-# include <ssl/rsa.h>
-#endif
+#include "cipher.h"
#include "kex.h"
#include "key.h"
-#include "dsa.h"
-
-#include "auth.h"
+#include "dh.h"
#include "myproposal.h"
+#include "authfile.h"
+#include "pathnames.h"
+#include "atomicio.h"
+#include "canohost.h"
+#include "auth.h"
+#include "misc.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>
#define O_NOCTTY 0
#endif
+#ifdef HAVE___PROGNAME
+extern char *__progname;
+#else
+char *__progname;
+#endif
+
/* Server configuration options. */
ServerOptions options;
/* Name of the server configuration file. */
-char *config_file_name = SERVER_CONFIG_FILE;
+char *config_file_name = _PATH_SERVER_CONFIG_FILE;
-/*
+/*
* 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
-
-/* Flag indicating whether SSH2 is enabled */
-int allow_ssh2 = 0;
/*
* Debug mode flag. This can be set on the command line. If debug
*/
int debug_flag = 0;
+/* Flag indicating that the daemon should only test the configuration and keys. */
+int test_flag = 0;
+
/* Flag indicating that the daemon is being started from inetd. */
int inetd_flag = 0;
+/* Flag indicating that sshd should not detach and become a daemon. */
+int no_daemon_flag = 0;
+
/* debug goes to stderr unless inetd_flag is set */
int log_stderr = 0;
-/* argv[0] without path. */
-char *av0;
-
/* Saved arguments to main(). */
char **saved_argv;
+int saved_argc;
/*
* The sockets that the server is listening; this is used in the SIGHUP
char *client_version_string = NULL;
char *server_version_string = NULL;
+/* for rekeying XXX fixme */
+Kex *xxx_kex;
+
/*
* Any really sensitive data in the application is contained in this
* structure. The idea is that this structure could be locked into memory so
* not very useful. Currently, memory locking is not implemented.
*/
struct {
- RSA *private_key; /* Private part of server key. */
- RSA *host_key; /* Private part of host key. */
+ Key *server_key; /* ephemeral server key */
+ Key *ssh1_host_key; /* ssh1 host key */
+ Key **host_keys; /* all private host keys */
+ int have_ssh1_key;
+ int have_ssh2_key;
+ u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
} sensitive_data;
/*
- * Flag indicating whether the current session key has been used. This flag
- * is set whenever the key is used, and cleared when the key is regenerated.
+ * Flag indicating whether the RSA server key needs to be regenerated.
+ * Is set in the SIGALRM handler and cleared when the key is regenerated.
*/
-int key_used = 0;
+static volatile sig_atomic_t key_do_regen = 0;
-/* This is set to true when SIGHUP is received. */
-int received_sighup = 0;
-
-/* Public side of the server key. This value is regenerated regularly with
- the private key. */
-RSA *public_key;
+/* This is set to true when a signal is received. */
+static volatile sig_atomic_t received_sighup = 0;
+static volatile sig_atomic_t received_sigterm = 0;
/* session identifier, used by RSA-auth */
-unsigned char session_id[16];
+u_char session_id[16];
+
+/* same for ssh2 */
+u_char *session_id2 = NULL;
+u_int session_id2_len = 0;
+
+/* record remote hostname or ip */
+u_int utmp_len = MAXHOSTNAMELEN;
+
+/* options.max_startup sized array of fd ints */
+int *startup_pipes = NULL;
+int startup_pipe; /* in child */
+
+/* variables used for privilege separation */
+int use_privsep;
+struct monitor *pmonitor;
+
+/* message to be displayed after login */
+Buffer loginmsg;
/* Prototypes for various functions defined later in this file. */
-void do_ssh1_kex();
-void do_ssh2_kex();
+void destroy_sensitive_data(void);
+void demote_sensitive_data(void);
+
+static void do_ssh1_kex(void);
+static void do_ssh2_kex(void);
/*
* Close all listening sockets
*/
-void
+static void
close_listen_socks(void)
{
int i;
+
for (i = 0; i < num_listen_socks; i++)
close(listen_socks[i]);
num_listen_socks = -1;
}
+static void
+close_startup_pipes(void)
+{
+ int i;
+
+ if (startup_pipes)
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1)
+ close(startup_pipes[i]);
+}
+
/*
* Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
* the effect is to reread the configuration file (and to regenerate
* the server key).
*/
-void
+static void
sighup_handler(int sig)
{
+ int save_errno = errno;
+
received_sighup = 1;
signal(SIGHUP, sighup_handler);
+ errno = save_errno;
}
/*
* Called from the main program after receiving SIGHUP.
* Restarts the server.
*/
-void
-sighup_restart()
+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: av0='%s', error: %s.", av0, strerror(errno));
+ logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
+ strerror(errno));
exit(1);
}
/*
* Generic signal handler for terminating signals in the master daemon.
- * These close the listen socket; not closing it seems to cause "Address
- * already in use" problems on some machines, which is inconvenient.
*/
-void
+static void
sigterm_handler(int sig)
{
- log("Received signal %d; terminating.", sig);
- close_listen_socks();
- exit(255);
+ received_sigterm = sig;
}
/*
* SIGCHLD handler. This is called whenever a child dies. This will then
- * reap any zombies left by exited c.
+ * reap any zombies left by exited children.
*/
-void
+static void
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);
/*
* Signal handler for the alarm after the login grace period has expired.
*/
-void
+static void
grace_alarm_handler(int sig)
{
- /* Close the connection. */
- packet_close();
+ /* XXX no idea how fix this signal handler */
/* Log error and exit. */
- fatal("Timeout before authentication for %s.", get_remote_ipaddr());
+ fatal("Timeout before authentication for %s", get_remote_ipaddr());
}
/*
* Thus there should be no concurrency control/asynchronous execution
* problems.
*/
-void
-key_regeneration_alarm(int sig)
+static void
+generate_ephemeral_server_key(void)
{
- int save_errno = errno;
-
- /* Check if we should generate a new key. */
- if (key_used) {
- /* This should really be done in the background. */
- log("Generating new %d bit RSA key.", options.server_key_bits);
-
- if (sensitive_data.private_key != NULL)
- RSA_free(sensitive_data.private_key);
- sensitive_data.private_key = RSA_new();
+ u_int32_t rnd = 0;
+ int i;
- if (public_key != NULL)
- RSA_free(public_key);
- public_key = RSA_new();
+ verbose("Generating %s%d bit RSA key.",
+ sensitive_data.server_key ? "new " : "", options.server_key_bits);
+ if (sensitive_data.server_key != NULL)
+ key_free(sensitive_data.server_key);
+ sensitive_data.server_key = key_generate(KEY_RSA1,
+ options.server_key_bits);
+ verbose("RSA key generation complete.");
- rsa_generate_key(sensitive_data.private_key, public_key,
- options.server_key_bits);
- arc4random_stir();
- key_used = 0;
- log("RSA key generation complete.");
+ for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
+ if (i % 4 == 0)
+ rnd = arc4random();
+ sensitive_data.ssh1_cookie[i] = rnd & 0xff;
+ rnd >>= 8;
}
- /* Reschedule the alarm. */
- signal(SIGALRM, key_regeneration_alarm);
- alarm(options.key_regeneration_time);
- errno = save_errno;
+ arc4random_stir();
}
-char *
-chop(char *s)
+static void
+key_regeneration_alarm(int sig)
{
- char *t = s;
- while (*t) {
- if(*t == '\n' || *t == '\r') {
- *t = '\0';
- return s;
- }
- t++;
- }
- return s;
+ int save_errno = errno;
+ signal(SIGALRM, SIG_DFL);
+ errno = save_errno;
+ key_do_regen = 1;
}
-void
+static void
sshd_exchange_identification(int sock_in, int sock_out)
{
- int i;
+ int i, mismatch;
int remote_major, remote_minor;
+ int major, minor;
char *s;
char buf[256]; /* Must not be larger than remote_version. */
char remote_version[256]; /* Must be at least as big as buf. */
- snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n",
- allow_ssh2 ? 1 : PROTOCOL_MAJOR,
- allow_ssh2 ? 99 : PROTOCOL_MINOR,
- SSH_VERSION);
+ if ((options.protocol & SSH_PROTO_1) &&
+ (options.protocol & SSH_PROTO_2)) {
+ major = PROTOCOL_MAJOR_1;
+ minor = 99;
+ } else if (options.protocol & SSH_PROTO_2) {
+ major = PROTOCOL_MAJOR_2;
+ minor = PROTOCOL_MINOR_2;
+ } else {
+ major = PROTOCOL_MAJOR_1;
+ minor = PROTOCOL_MINOR_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());
+ /* 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());
+ fatal_cleanup();
+ }
+
+ /* 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());
fatal_cleanup();
}
-
- /* Read other side\'s version identification. */
- for (i = 0; i < sizeof(buf) - 1; i++) {
- if (read(sock_in, &buf[i], 1) != 1) {
- log("Did not receive ident string from %s.", get_remote_ipaddr());
- fatal_cleanup();
- }
- if (buf[i] == '\r') {
- buf[i] = '\n';
- buf[i + 1] = 0;
- continue;
- //break;
- }
- if (buf[i] == '\n') {
- /* buf[i] == '\n' */
- buf[i + 1] = 0;
+ 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));
+ s = "Protocol mismatch.\n";
+ (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();
}
debug("Client protocol version %d.%d; client software version %.100s",
- remote_major, remote_minor, remote_version);
+ remote_major, remote_minor, remote_version);
compat_datafellows(remote_version);
- switch(remote_major) {
+ if (datafellows & SSH_BUG_PROBE) {
+ logit("probed from %s with %s. Don't panic.",
+ get_remote_ipaddr(), client_version_string);
+ fatal_cleanup();
+ }
+
+ if (datafellows & SSH_BUG_SCANNER) {
+ logit("scanned from %s with %s. Don't panic.",
+ get_remote_ipaddr(), client_version_string);
+ fatal_cleanup();
+ }
+
+ mismatch = 0;
+ switch (remote_major) {
case 1:
+ if (remote_minor == 99) {
+ if (options.protocol & SSH_PROTO_2)
+ enable_compat20();
+ else
+ mismatch = 1;
+ break;
+ }
+ if (!(options.protocol & SSH_PROTO_1)) {
+ mismatch = 1;
+ break;
+ }
if (remote_minor < 3) {
- packet_disconnect("Your ssh version is too old and"
+ packet_disconnect("Your ssh version is too old and "
"is no longer supported. Please install a newer version.");
} else if (remote_minor == 3) {
/* note that this disables agent-forwarding */
enable_compat13();
}
- if (remote_minor != 99)
- break;
- /* FALLTHROUGH */
+ break;
case 2:
- if (allow_ssh2) {
+ if (options.protocol & SSH_PROTO_2) {
enable_compat20();
break;
}
/* FALLTHROUGH */
- default:
+ default:
+ mismatch = 1;
+ break;
+ }
+ chop(server_version_string);
+ debug("Local version string %.200s", server_version_string);
+
+ 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: %d vs. %d",
- get_remote_ipaddr(), PROTOCOL_MAJOR, remote_major);
+ logit("Protocol major versions differ for %s: %.200s vs. %.200s",
+ get_remote_ipaddr(),
+ server_version_string, client_version_string);
fatal_cleanup();
- break;
}
- chop(server_version_string);
- chop(client_version_string);
+}
+
+/* Destroy the host and server keys. They will no longer be needed. */
+void
+destroy_sensitive_data(void)
+{
+ int i;
+
+ if (sensitive_data.server_key) {
+ key_free(sensitive_data.server_key);
+ sensitive_data.server_key = NULL;
+ }
+ for (i = 0; i < options.num_host_key_files; i++) {
+ if (sensitive_data.host_keys[i]) {
+ key_free(sensitive_data.host_keys[i]);
+ sensitive_data.host_keys[i] = NULL;
+ }
+ }
+ sensitive_data.ssh1_host_key = NULL;
+ 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, to 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 Authctxt *
+privsep_preauth(void)
+{
+ Authctxt *authctxt = NULL;
+ 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) {
+ 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(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) {
+ 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(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;
+ int i;
+
+ buffer_init(&b);
+ for (i = 0; i < options.num_host_key_files; i++) {
+ Key *key = sensitive_data.host_keys[i];
+ if (key == NULL)
+ continue;
+ switch (key->type) {
+ case KEY_RSA:
+ case KEY_DSA:
+ if (buffer_len(&b) > 0)
+ buffer_append(&b, ",", 1);
+ p = key_ssh_name(key);
+ buffer_append(&b, p, strlen(p));
+ break;
+ }
+ }
+ buffer_append(&b, "\0", 1);
+ p = xstrdup(buffer_ptr(&b));
+ buffer_free(&b);
+ debug("list_hostkey_types: %s", p);
+ return p;
+}
+
+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 key;
+ }
+ 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
+ * of (max_startups_rate/100). the probability increases linearly until
+ * all connections are dropped for startups > max_startups
+ */
+static int
+drop_connection(int startups)
+{
+ double p, r;
+
+ if (startups < options.max_startups_begin)
+ return 0;
+ if (startups >= options.max_startups)
+ return 1;
+ if (options.max_startups_rate == 100)
+ return 1;
+
+ p = 100 - options.max_startups_rate;
+ p *= startups - options.max_startups_begin;
+ p /= (double) (options.max_startups - options.max_startups_begin);
+ p += options.max_startups_rate;
+ p /= 100.0;
+ r = arc4random() / (double) UINT_MAX;
+
+ debug("drop_connection: p %g, r %g", p, r);
+ return (r < p) ? 1 : 0;
+}
+
+static void
+usage(void)
+{
+ fprintf(stderr, "sshd version %s\n", SSH_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);
+ fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
+ fprintf(stderr, " -i Started from inetd\n");
+ fprintf(stderr, " -D Do not fork into daemon mode\n");
+ fprintf(stderr, " -t Only test configuration file and keys\n");
+ fprintf(stderr, " -q Quiet (no logging)\n");
+ fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
+ fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
+ fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
+ fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
+ fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
+ _PATH_HOST_KEY_FILE);
+ fprintf(stderr, " -u len Maximum hostname length for utmp recording\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");
+ exit(1);
}
/*
{
extern char *optarg;
extern int optind;
- int opt, sock_in = 0, sock_out = 0, newsock, i, fdsetsz, pid, on = 1;
+ int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
+ pid_t pid;
socklen_t fromlen;
- int silentrsa = 0;
fd_set *fdset;
struct sockaddr_storage from;
const char *remote_ip;
int remote_port;
- char *comment;
FILE *f;
- struct linger linger;
struct addrinfo *ai;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
int listen_sock, maxfd;
-
- /* Save argv[0]. */
- saved_argv = av;
- if (strchr(av[0], '/'))
- av0 = strrchr(av[0], '/') + 1;
- else
- av0 = av[0];
+ int startup_p[2];
+ int startups = 0;
+ Authctxt *authctxt;
+ Key *key;
+ int ret, key_used = 0;
+
+#ifdef HAVE_SECUREWARE
+ (void)set_auth_parameters(ac, av);
+#endif
+ __progname = ssh_get_progname(av[0]);
+ init_rng();
+
+ /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
+ saved_argc = ac;
+ 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:diqQ246")) != EOF) {
+ while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqtQ46")) != -1) {
switch (opt) {
- case '2':
- allow_ssh2 = 1;
- break;
case '4':
IPv4or6 = AF_INET;
break;
config_file_name = optarg;
break;
case 'd':
- debug_flag = 1;
- options.log_level = SYSLOG_LEVEL_DEBUG;
+ 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;
+ case 'D':
+ no_daemon_flag = 1;
+ break;
+ case 'e':
+ log_stderr = 1;
break;
case 'i':
inetd_flag = 1;
break;
case 'Q':
- silentrsa = 1;
+ /* ignored */
break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
case 'p':
options.ports_from_cmdline = 1;
- if (options.num_ports >= MAX_PORTS)
- fatal("too many ports.\n");
- options.ports[options.num_ports++] = atoi(optarg);
+ if (options.num_ports >= MAX_PORTS) {
+ fprintf(stderr, "too many ports.\n");
+ exit(1);
+ }
+ options.ports[options.num_ports++] = a2port(optarg);
+ if (options.ports[options.num_ports-1] == 0) {
+ fprintf(stderr, "Bad port number.\n");
+ exit(1);
+ }
break;
case 'g':
- options.login_grace_time = atoi(optarg);
+ if ((options.login_grace_time = convtime(optarg)) == -1) {
+ fprintf(stderr, "Invalid login grace time.\n");
+ exit(1);
+ }
break;
case 'k':
- options.key_regeneration_time = atoi(optarg);
+ if ((options.key_regeneration_time = convtime(optarg)) == -1) {
+ fprintf(stderr, "Invalid key regeneration interval.\n");
+ exit(1);
+ }
break;
case 'h':
- options.host_key_file = optarg;
+ if (options.num_host_key_files >= MAX_HOSTKEYS) {
+ fprintf(stderr, "too many host keys.\n");
+ exit(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;
+ 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,
+ "command-line", 0) != 0)
+ exit(1);
break;
case '?':
default:
- fprintf(stderr, "sshd version %s\n", SSH_VERSION);
- fprintf(stderr, "Usage: %s [options]\n", av0);
- fprintf(stderr, "Options:\n");
- fprintf(stderr, " -f file Configuration file (default %s)\n", SERVER_CONFIG_FILE);
- fprintf(stderr, " -d Debugging mode\n");
- fprintf(stderr, " -i Started from inetd\n");
- fprintf(stderr, " -q Quiet (no logging)\n");
- fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
- fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
- fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n");
- fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
- fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
- HOST_KEY_FILE);
- fprintf(stderr, " -4 Use IPv4 only\n");
- fprintf(stderr, " -6 Use IPv6 only\n");
- exit(1);
+ usage();
+ break;
}
}
+ SSLeay_add_all_algorithms();
+ channel_set_af(IPv4or6);
/*
* Force logging to stderr until we have loaded the private host
* key (unless started from inetd)
*/
- log_init(av0,
- options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
- options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
- !inetd_flag);
-
- /* check if RSA support exists */
- if (rsa_alive() == 0) {
- if (silentrsa == 0)
- printf("sshd: no RSA support in libssl and libcrypto -- exiting. See ssl(8)\n");
- log("no RSA support in libssl and libcrypto -- exiting. See ssl(8)");
- exit(1);
- }
+ log_init(__progname,
+ options.log_level == SYSLOG_LEVEL_NOT_SET ?
+ SYSLOG_LEVEL_INFO : options.log_level,
+ options.log_facility == SYSLOG_FACILITY_NOT_SET ?
+ SYSLOG_FACILITY_AUTH : options.log_facility,
+ log_stderr || !inetd_flag);
+
+#ifdef _UNICOS
+ /* Cray can define user privs drop all prives now!
+ * Not needed on PRIV_SU systems!
+ */
+ drop_cray_privs();
+#endif
+
+ seed_rng();
+
/* Read server configuration options from the configuration file. */
read_server_config(&options, config_file_name);
/* Fill in default values for those options not explicitly set. */
fill_default_server_options(&options);
- /* Check certain values for sanity. */
- if (options.server_key_bits < 512 ||
- options.server_key_bits > 32768) {
- fprintf(stderr, "Bad server key size.\n");
- exit(1);
- }
/* Check that there are no remaining arguments. */
if (optind < ac) {
fprintf(stderr, "Extra argument %s.\n", av[optind]);
debug("sshd version %.100s", SSH_VERSION);
- sensitive_data.host_key = RSA_new();
- errno = 0;
- /* Load the host key. It must have empty passphrase. */
- if (!load_private_key(options.host_key_file, "",
- sensitive_data.host_key, &comment)) {
- error("Could not load host key: %.200s: %.100s",
- options.host_key_file, strerror(errno));
+ /* load private host keys */
+ 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;
+ sensitive_data.ssh1_host_key = NULL;
+ sensitive_data.have_ssh1_key = 0;
+ sensitive_data.have_ssh2_key = 0;
+
+ for (i = 0; i < options.num_host_key_files; i++) {
+ key = key_load_private(options.host_key_files[i], "", NULL);
+ sensitive_data.host_keys[i] = key;
+ if (key == NULL) {
+ error("Could not load host key: %s",
+ options.host_key_files[i]);
+ sensitive_data.host_keys[i] = NULL;
+ continue;
+ }
+ switch (key->type) {
+ case KEY_RSA1:
+ sensitive_data.ssh1_host_key = key;
+ sensitive_data.have_ssh1_key = 1;
+ break;
+ case KEY_RSA:
+ case KEY_DSA:
+ sensitive_data.have_ssh2_key = 1;
+ break;
+ }
+ debug("private host key: #%d type %d %s", i, key->type,
+ key_type(key));
+ }
+ if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_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) {
+ logit("Disabling protocol version 2. Could not load host key");
+ options.protocol &= ~SSH_PROTO_2;
+ }
+ if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
+ logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
- xfree(comment);
- /* Initialize the log (it is reinitialized below in case we
- forked). */
+ /* Check certain values for sanity. */
+ if (options.protocol & SSH_PROTO_1) {
+ if (options.server_key_bits < 512 ||
+ options.server_key_bits > 32768) {
+ fprintf(stderr, "Bad server key size.\n");
+ exit(1);
+ }
+ /*
+ * Check that server and host key lengths differ sufficiently. This
+ * is necessary to make double encryption work with rsaref. Oh, I
+ * 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) {
+ options.server_key_bits =
+ 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);
+
+ /*
+ * 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)
log_stderr = 1;
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
- /* If not in debugging mode, and not started from inetd,
- disconnect from the controlling terminal, and fork. The
- original process exits. */
- if (!debug_flag && !inetd_flag) {
+ /*
+ * If not in debugging mode, and not started from inetd, disconnect
+ * from the controlling terminal, and fork. The original process
+ * exits.
+ */
+ if (!(debug_flag || inetd_flag || no_daemon_flag)) {
#ifdef TIOCNOTTY
int fd;
#endif /* TIOCNOTTY */
/* Disconnect from the controlling tty. */
#ifdef TIOCNOTTY
- fd = open("/dev/tty", O_RDWR | O_NOCTTY);
+ fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
if (fd >= 0) {
(void) ioctl(fd, TIOCNOTTY, NULL);
close(fd);
#endif /* TIOCNOTTY */
}
/* Reinitialize the log (because of the fork above). */
- log_init(av0, options.log_level, options.log_facility, log_stderr);
-
- /* Check that server and host key lengths differ sufficiently.
- This is necessary to make double encryption work with rsaref.
- Oh, I hate software patents. I dont know if this can go? Niels */
- if (options.server_key_bits >
- BN_num_bits(sensitive_data.host_key->n) - SSH_KEY_BITS_RESERVED &&
- options.server_key_bits <
- BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) {
- options.server_key_bits =
- BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED;
- debug("Forcing server key to %d bits to make it differ from host key.",
- options.server_key_bits);
- }
- /* Do not display messages to stdout in RSA code. */
- rsa_set_verbose(0);
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
/* Initialize the random number generator. */
arc4random_stir();
unmounted if desired. */
chdir("/");
+ /* ignore SIGPIPE */
+ signal(SIGPIPE, SIG_IGN);
+
/* Start listening for a socket, unless started from inetd. */
if (inetd_flag) {
- int s1, s2;
+ int s1;
s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
- s2 = dup(s1);
+ dup(s1);
sock_in = dup(0);
sock_out = dup(1);
- /* We intentionally do not close the descriptors 0, 1, and 2
- as our code for setting the descriptors won\'t work
- if ttyfd happens to be one of those. */
+ startup_pipe = -1;
+ /*
+ * We intentionally do not close the descriptors 0, 1, and 2
+ * as our code for setting the descriptors won\'t work if
+ * ttyfd happens to be one of those.
+ */
debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
-
- public_key = RSA_new();
- sensitive_data.private_key = RSA_new();
-
- log("Generating %d bit RSA key.", options.server_key_bits);
- rsa_generate_key(sensitive_data.private_key, public_key,
- options.server_key_bits);
- arc4random_stir();
- log("RSA key generation complete.");
+ if (options.protocol & SSH_PROTO_1)
+ generate_ephemeral_server_key();
} else {
for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
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,
- (void *) &on, sizeof(on));
- linger.l_onoff = 1;
- linger.l_linger = 5;
- setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
- (void *) &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);
/* Bind the socket to the desired port. */
- if ((bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) &&
- (!ai->ai_next)) {
- error("Bind to port %s on %s failed: %.200s.",
- strport, ntop, strerror(errno));
+ if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ if (!ai->ai_next)
+ error("Bind to port %s on %s failed: %.200s.",
+ strport, ntop, strerror(errno));
close(listen_sock);
continue;
}
num_listen_socks++;
/* Start listening on the port. */
- log("Server listening on %s port %s.", ntop, strport);
+ logit("Server listening on %s port %s.", ntop, strport);
if (listen(listen_sock, 5) < 0)
fatal("listen: %.100s", strerror(errno));
if (!num_listen_socks)
fatal("Cannot bind any address.");
+ if (options.protocol & SSH_PROTO_1)
+ generate_ephemeral_server_key();
+
+ /*
+ * Arrange to restart on SIGHUP. The handler needs
+ * listen_sock.
+ */
+ signal(SIGHUP, sighup_handler);
+
+ signal(SIGTERM, sigterm_handler);
+ signal(SIGQUIT, sigterm_handler);
+
+ /* Arrange SIGCHLD to be caught. */
+ signal(SIGCHLD, main_sigchld_handler);
+
+ /* Write out the pid file after the sigterm handler is setup */
if (!debug_flag) {
/*
- * Record our pid in /etc/sshd_pid to make it easier
- * to kill the correct sshd. We don\'t want to do
- * this before the bind above because the bind will
+ * Record our pid in /var/run/sshd.pid to make it
+ * easier to kill the correct sshd. We don't want to
+ * do this before the bind above because the bind will
* fail if there already is a daemon, and this will
* overwrite any old pid in the file.
*/
- f = fopen(SSH_DAEMON_PID_FILE, "w");
- if (f) {
- fprintf(f, "%u\n", (unsigned int) getpid());
+ f = fopen(options.pid_file, "wb");
+ 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);
}
}
- public_key = RSA_new();
- sensitive_data.private_key = RSA_new();
-
- log("Generating %d bit RSA key.", options.server_key_bits);
- rsa_generate_key(sensitive_data.private_key, public_key,
- options.server_key_bits);
- arc4random_stir();
- log("RSA key generation complete.");
-
- /* Schedule server key regeneration alarm. */
- signal(SIGALRM, key_regeneration_alarm);
- alarm(options.key_regeneration_time);
-
- /* Arrange to restart on SIGHUP. The handler needs listen_sock. */
- signal(SIGHUP, sighup_handler);
- signal(SIGTERM, sigterm_handler);
- signal(SIGQUIT, sigterm_handler);
-
- /* Arrange SIGCHLD to be caught. */
- signal(SIGCHLD, main_sigchld_handler);
-
/* setup fd set for listen */
+ fdset = NULL;
maxfd = 0;
for (i = 0; i < num_listen_socks; i++)
if (listen_socks[i] > maxfd)
maxfd = listen_socks[i];
- fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
- fdset = (fd_set *)xmalloc(fdsetsz);
+ /* pipes connected to unauthenticated childs */
+ startup_pipes = xmalloc(options.max_startups * sizeof(int));
+ for (i = 0; i < options.max_startups; i++)
+ startup_pipes[i] = -1;
/*
* Stay listening for connections until the system crashes or
for (;;) {
if (received_sighup)
sighup_restart();
- /* Wait in select until there is a connection. */
+ if (fdset != NULL)
+ xfree(fdset);
+ fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
+ fdset = (fd_set *)xmalloc(fdsetsz);
memset(fdset, 0, fdsetsz);
+
for (i = 0; i < num_listen_socks; i++)
FD_SET(listen_socks[i], fdset);
- if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
- if (errno != EINTR)
- error("select: %.100s", strerror(errno));
- continue;
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1)
+ FD_SET(startup_pipes[i], fdset);
+
+ /* Wait in select until there is a connection. */
+ ret = select(maxfd+1, fdset, NULL, NULL, NULL);
+ if (ret < 0 && errno != EINTR)
+ error("select: %.100s", strerror(errno));
+ if (received_sigterm) {
+ logit("Received signal %d; terminating.",
+ (int) received_sigterm);
+ close_listen_socks();
+ unlink(options.pid_file);
+ exit(255);
}
+ if (key_used && key_do_regen) {
+ generate_ephemeral_server_key();
+ key_used = 0;
+ key_do_regen = 0;
+ }
+ if (ret < 0)
+ continue;
+
+ for (i = 0; i < options.max_startups; i++)
+ if (startup_pipes[i] != -1 &&
+ FD_ISSET(startup_pipes[i], fdset)) {
+ /*
+ * the read end of the pipe is ready
+ * if the child has closed the pipe
+ * after successful authentication
+ * or if the child has died
+ */
+ close(startup_pipes[i]);
+ startup_pipes[i] = -1;
+ startups--;
+ }
for (i = 0; i < num_listen_socks; i++) {
if (!FD_ISSET(listen_socks[i], fdset))
continue;
- fromlen = sizeof(from);
- newsock = accept(listen_socks[i], (struct sockaddr *)&from,
- &fromlen);
- if (newsock < 0) {
- if (errno != EINTR && errno != EWOULDBLOCK)
- error("accept: %.100s", strerror(errno));
- continue;
- }
- if (fcntl(newsock, F_SETFL, 0) < 0) {
- error("newsock del O_NONBLOCK: %s", strerror(errno));
- continue;
- }
- /*
- * Got connection. Fork a child to handle it, unless
- * we are in debugging mode.
- */
- if (debug_flag) {
- /*
- * In debugging mode. Close the listening
- * socket, and start processing the
- * connection without forking.
- */
- debug("Server will not fork when running in debugging mode.");
- close_listen_socks();
- sock_in = newsock;
- sock_out = newsock;
- pid = getpid();
- break;
- } else {
+ fromlen = sizeof(from);
+ newsock = accept(listen_socks[i], (struct sockaddr *)&from,
+ &fromlen);
+ if (newsock < 0) {
+ if (errno != EINTR && errno != EWOULDBLOCK)
+ error("accept: %.100s", strerror(errno));
+ continue;
+ }
+ if (fcntl(newsock, F_SETFL, 0) < 0) {
+ error("newsock del O_NONBLOCK: %s", strerror(errno));
+ close(newsock);
+ continue;
+ }
+ if (drop_connection(startups) == 1) {
+ debug("drop connection #%d", startups);
+ close(newsock);
+ continue;
+ }
+ if (pipe(startup_p) == -1) {
+ close(newsock);
+ continue;
+ }
+
+ for (j = 0; j < options.max_startups; j++)
+ if (startup_pipes[j] == -1) {
+ startup_pipes[j] = startup_p[0];
+ if (maxfd < startup_p[0])
+ maxfd = startup_p[0];
+ startups++;
+ break;
+ }
+
/*
- * Normal production daemon. Fork, and have
- * the child process the connection. The
- * parent continues listening.
+ * Got connection. Fork a child to handle it, unless
+ * we are in debugging mode.
*/
- if ((pid = fork()) == 0) {
+ if (debug_flag) {
/*
- * Child. Close the listening socket, and start using the
- * accepted socket. Reinitialize logging (since our pid has
- * changed). We break out of the loop to handle the connection.
+ * In debugging mode. Close the listening
+ * socket, and start processing the
+ * connection without forking.
*/
+ debug("Server will not fork when running in debugging mode.");
close_listen_socks();
sock_in = newsock;
sock_out = newsock;
- log_init(av0, options.log_level, options.log_facility, log_stderr);
+ startup_pipe = -1;
+ pid = getpid();
break;
+ } else {
+ /*
+ * Normal production daemon. Fork, and have
+ * the child process the connection. The
+ * parent continues listening.
+ */
+ if ((pid = fork()) == 0) {
+ /*
+ * Child. Close the listening and max_startup
+ * sockets. Start using the accepted socket.
+ * Reinitialize logging (since our pid has
+ * changed). We break out of the loop to handle
+ * the connection.
+ */
+ startup_pipe = startup_p[1];
+ close_startup_pipes();
+ close_listen_socks();
+ sock_in = newsock;
+ sock_out = newsock;
+ log_init(__progname, options.log_level, options.log_facility, log_stderr);
+ break;
+ }
}
- }
-
- /* Parent. Stay in the loop. */
- if (pid < 0)
- error("fork: %.100s", strerror(errno));
- else
- debug("Forked child %d.", pid);
- /* Mark that the key has been used (it was "given" to the child). */
- key_used = 1;
+ /* Parent. Stay in the loop. */
+ if (pid < 0)
+ error("fork: %.100s", strerror(errno));
+ else
+ debug("Forked child %ld.", (long)pid);
+
+ close(startup_p[1]);
+
+ /* Mark that the key has been used (it was "given" to the child). */
+ if ((options.protocol & SSH_PROTO_1) &&
+ key_used == 0) {
+ /* Schedule server key regeneration alarm. */
+ signal(SIGALRM, key_regeneration_alarm);
+ alarm(options.key_regeneration_time);
+ key_used = 1;
+ }
- arc4random_stir();
+ arc4random_stir();
- /* Close the new socket (the child is now taking care of it). */
- close(newsock);
- } /* for (i = 0; i < num_listen_socks; i++) */
+ /* Close the new socket (the child is now taking care of it). */
+ close(newsock);
+ }
/* child process check (or debug mode) */
if (num_listen_socks < 0)
break;
/* 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 !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
* key since we are no longer in a position to give it to anyone. We
signal(SIGTERM, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
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, (void *) &linger, sizeof(linger));
+ /* Set keepalives if requested. */
+ if (options.keepalives &&
+ setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
+ sizeof(on)) < 0)
+ error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
/*
* Register our connection. This turns encryption off because we do
remote_port = get_remote_port();
remote_ip = get_remote_ipaddr();
- /* Check whether logins are denied from this host. */
#ifdef LIBWRAP
- /* XXX LIBWRAP noes not know about IPv6 */
+ /* Check whether logins are denied from this host. */
{
struct request_info req;
- request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL);
+ request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
fromhost(&req);
if (!hosts_access(&req)) {
- close(sock_in);
- close(sock_out);
+ debug("Connection refused by tcp wrapper");
refuse(&req);
+ /* NOTREACHED */
+ fatal("libwrap refuse returns");
}
-/*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */
}
#endif /* LIBWRAP */
+
/* Log the connection. */
verbose("Connection from %.500s port %d", remote_ip, remote_port);
alarm(options.login_grace_time);
sshd_exchange_identification(sock_in, sock_out);
- /*
- * Check that the connection comes from a privileged port. Rhosts-
- * and Rhosts-RSA-Authentication only make 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 (remote_port >= IPPORT_RESERVED ||
- remote_port < IPPORT_RESERVED / 2) {
- options.rhosts_authentication = 0;
- options.rhosts_rsa_authentication = 0;
- }
-#ifdef KRB4
- if (!packet_connection_is_ipv4() &&
- options.kerberos_authentication) {
- debug("Kerberos Authentication disabled, only available for IPv4.");
- options.kerberos_authentication = 0;
- }
-#endif /* KRB4 */
packet_set_nonblocking();
+ /* prepare buffers to collect authentication messages */
+ buffer_init(&loginmsg);
+
+ if (use_privsep)
+ if ((authctxt = privsep_preauth()) != NULL)
+ goto authenticated;
+
/* perform the key exchange */
/* authenticate user and start session */
if (compat20) {
do_ssh2_kex();
- do_authentication2();
+ authctxt = do_authentication2();
} else {
do_ssh1_kex();
- do_authentication();
+ authctxt = do_authentication();
+ }
+ /*
+ * If we use privilege separation, the unprivileged child transfers
+ * the current keystate and exits
+ */
+ if (use_privsep) {
+ mm_send_keystate(pmonitor);
+ exit(0);
}
-#ifdef KRB4
- /* Cleanup user's ticket cache file. */
- if (options.kerberos_ticket_cleanup)
- (void) dest_tkt();
-#endif /* KRB4 */
+ 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. */
+ 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).
+ */
+int
+ssh1_session_key(BIGNUM *session_key_int)
+{
+ int rsafail = 0;
+
+ if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
+ /* Server key has bigger modulus. */
+ if (BN_num_bits(sensitive_data.server_key->rsa->n) <
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
+ fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
+ get_remote_ipaddr(),
+ BN_num_bits(sensitive_data.server_key->rsa->n),
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
+ SSH_KEY_BITS_RESERVED);
+ }
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.server_key->rsa) <= 0)
+ rsafail++;
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.ssh1_host_key->rsa) <= 0)
+ rsafail++;
+ } else {
+ /* Host key has bigger modulus (or they are equal). */
+ if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
+ BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
+ fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
+ get_remote_ipaddr(),
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
+ BN_num_bits(sensitive_data.server_key->rsa->n),
+ SSH_KEY_BITS_RESERVED);
+ }
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.ssh1_host_key->rsa) < 0)
+ rsafail++;
+ if (rsa_private_decrypt(session_key_int, session_key_int,
+ sensitive_data.server_key->rsa) < 0)
+ rsafail++;
+ }
+ return (rsafail);
+}
/*
* SSH1 key exchange
*/
-void
-do_ssh1_kex()
+static void
+do_ssh1_kex(void)
{
int i, len;
- int plen, slen;
+ int rsafail = 0;
BIGNUM *session_key_int;
- unsigned char session_key[SSH_SESSION_KEY_LENGTH];
- unsigned char cookie[8];
- unsigned int cipher_type, auth_mask, protocol_flags;
- u_int32_t rand = 0;
+ u_char session_key[SSH_SESSION_KEY_LENGTH];
+ u_char cookie[8];
+ u_int cipher_type, auth_mask, protocol_flags;
+ 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;
}
/*
packet_put_char(cookie[i]);
/* Store our public server RSA key. */
- packet_put_int(BN_num_bits(public_key->n));
- packet_put_bignum(public_key->e);
- packet_put_bignum(public_key->n);
+ packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
+ packet_put_bignum(sensitive_data.server_key->rsa->e);
+ packet_put_bignum(sensitive_data.server_key->rsa->n);
/* Store our public host RSA key. */
- packet_put_int(BN_num_bits(sensitive_data.host_key->n));
- packet_put_bignum(sensitive_data.host_key->e);
- packet_put_bignum(sensitive_data.host_key->n);
+ packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
+ packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
+ packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
/* Put protocol flags. */
packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
/* Declare which ciphers we support. */
- packet_put_int(cipher_mask1());
+ packet_put_int(cipher_mask_ssh1(0));
/* 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;
-#ifdef KRB4
- if (options.kerberos_authentication)
- auth_mask |= 1 << SSH_AUTH_KERBEROS;
-#endif
-#ifdef AFS
- if (options.kerberos_tgt_passing)
- auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
- if (options.afs_token_passing)
- auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
-#endif
-#ifdef SKEY
- if (options.skey_authentication == 1)
+ if (options.challenge_response_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
-#endif
if (options.password_authentication)
auth_mask |= 1 << SSH_AUTH_PASSWORD;
packet_put_int(auth_mask);
packet_send();
packet_write_wait();
- debug("Sent %d bit public key and %d bit host key.",
- BN_num_bits(public_key->n), BN_num_bits(sensitive_data.host_key->n));
+ debug("Sent %d bit server key and %d bit host key.",
+ BN_num_bits(sensitive_data.server_key->rsa->n),
+ BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
/* Read clients reply (cipher type and session key). */
- packet_read_expect(&plen, SSH_CMSG_SESSION_KEY);
+ packet_read_expect(SSH_CMSG_SESSION_KEY);
/* Get cipher type and check whether we accept this. */
cipher_type = packet_get_char();
- if (!(cipher_mask() & (1 << cipher_type)))
+ if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
packet_disconnect("Warning: client selects unsupported cipher.");
/* Get check bytes from the packet. These must match those we
debug("Encryption type: %.200s", cipher_name(cipher_type));
/* Get the encrypted integer. */
- session_key_int = BN_new();
- packet_get_bignum(session_key_int, &slen);
+ if ((session_key_int = BN_new()) == NULL)
+ fatal("do_ssh1_kex: BN_new failed");
+ packet_get_bignum(session_key_int);
protocol_flags = packet_get_int();
packet_set_protocol_flags(protocol_flags);
+ packet_check_eom();
- packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY);
-
- /*
- * Decrypt it using our private server key and private host key (key
- * with larger modulus first).
- */
- if (BN_cmp(sensitive_data.private_key->n, sensitive_data.host_key->n) > 0) {
- /* Private key has bigger modulus. */
- if (BN_num_bits(sensitive_data.private_key->n) <
- BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) {
- fatal("do_connection: %s: private_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
- get_remote_ipaddr(),
- BN_num_bits(sensitive_data.private_key->n),
- BN_num_bits(sensitive_data.host_key->n),
- SSH_KEY_BITS_RESERVED);
- }
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.private_key);
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.host_key);
- } else {
- /* Host key has bigger modulus (or they are equal). */
- if (BN_num_bits(sensitive_data.host_key->n) <
- BN_num_bits(sensitive_data.private_key->n) + SSH_KEY_BITS_RESERVED) {
- fatal("do_connection: %s: host_key %d < private_key %d + SSH_KEY_BITS_RESERVED %d",
- get_remote_ipaddr(),
- BN_num_bits(sensitive_data.host_key->n),
- BN_num_bits(sensitive_data.private_key->n),
- SSH_KEY_BITS_RESERVED);
- }
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.host_key);
- rsa_private_decrypt(session_key_int, session_key_int,
- sensitive_data.private_key);
- }
-
- compute_session_id(session_id, cookie,
- sensitive_data.host_key->n,
- sensitive_data.private_key->n);
-
- /* Destroy the private and public keys. They will no longer be needed. */
- RSA_free(public_key);
- RSA_free(sensitive_data.private_key);
- RSA_free(sensitive_data.host_key);
+ /* Decrypt session_key_int using host/server keys */
+ 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
* key is in the highest bits.
*/
- BN_mask_bits(session_key_int, sizeof(session_key) * 8);
- len = BN_num_bytes(session_key_int);
- if (len < 0 || len > sizeof(session_key))
- fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d",
- get_remote_ipaddr(),
- len, sizeof(session_key));
- memset(session_key, 0, sizeof(session_key));
- BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len);
+ if (!rsafail) {
+ BN_mask_bits(session_key_int, sizeof(session_key) * 8);
+ len = BN_num_bytes(session_key_int);
+ if (len < 0 || len > sizeof(session_key)) {
+ error("do_connection: bad session key len from %s: "
+ "session_key_int %d > sizeof(session_key) %lu",
+ get_remote_ipaddr(), len, (u_long)sizeof(session_key));
+ rsafail++;
+ } else {
+ memset(session_key, 0, sizeof(session_key));
+ BN_bn2bin(session_key_int,
+ session_key + sizeof(session_key) - len);
+
+ compute_session_id(session_id, cookie,
+ sensitive_data.ssh1_host_key->rsa->n,
+ sensitive_data.server_key->rsa->n);
+ /*
+ * Xor the first 16 bytes of the session key with the
+ * session id.
+ */
+ for (i = 0; i < 16; i++)
+ session_key[i] ^= session_id[i];
+ }
+ }
+ if (rsafail) {
+ int bytes = BN_num_bytes(session_key_int);
+ u_char *buf = xmalloc(bytes);
+ MD5_CTX md;
+
+ logit("do_connection: generating a fake encryption key");
+ BN_bn2bin(session_key_int, buf);
+ MD5_Init(&md);
+ MD5_Update(&md, buf, bytes);
+ MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
+ MD5_Final(session_key, &md);
+ MD5_Init(&md);
+ MD5_Update(&md, session_key, 16);
+ MD5_Update(&md, buf, bytes);
+ MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
+ MD5_Final(session_key + 16, &md);
+ memset(buf, 0, bytes);
+ xfree(buf);
+ for (i = 0; i < 16; i++)
+ session_id[i] = session_key[i] ^ session_key[i + 16];
+ }
+ /* 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);
- /* Xor the first 16 bytes of the session key with the session id. */
- for (i = 0; i < 16; i++)
- session_key[i] ^= session_id[i];
-
/* Set the session key. From this on all communications will be encrypted. */
packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
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();
/*
* SSH2 key exchange: diffie-hellman-group1-sha1
*/
-void
-do_ssh2_kex()
+static void
+do_ssh2_kex(void)
{
- Buffer *server_kexinit;
- Buffer *client_kexinit;
- int payload_len, dlen;
- int slen;
- unsigned int klen, kout;
- char *ptr;
- unsigned char *signature = NULL;
- unsigned char *server_host_key_blob = NULL;
- unsigned int sbloblen;
- DH *dh;
- BIGNUM *dh_client_pub = 0;
- BIGNUM *shared_secret = 0;
- int i;
- unsigned char *kbuf;
- unsigned char *hash;
Kex *kex;
- Key *server_host_key;
- char *cprop[PROPOSAL_MAX];
- char *sprop[PROPOSAL_MAX];
-
-/* KEXINIT */
-
- debug("Sending KEX init.");
-
- for (i = 0; i < PROPOSAL_MAX; i++)
- sprop[i] = xstrdup(myproposal[i]);
- server_kexinit = kex_init(sprop);
- packet_start(SSH2_MSG_KEXINIT);
- packet_put_raw(buffer_ptr(server_kexinit), buffer_len(server_kexinit));
- packet_send();
- packet_write_wait();
-
- debug("done");
- packet_read_expect(&payload_len, SSH2_MSG_KEXINIT);
-
- /*
- * save raw KEXINIT payload in buffer. this is used during
- * computation of the session_id and the session keys.
- */
- client_kexinit = xmalloc(sizeof(*client_kexinit));
- buffer_init(client_kexinit);
- ptr = packet_get_raw(&payload_len);
- buffer_append(client_kexinit, ptr, payload_len);
-
- /* skip cookie */
- for (i = 0; i < 16; i++)
- (void) packet_get_char();
- /* save kex init proposal strings */
- for (i = 0; i < PROPOSAL_MAX; i++) {
- cprop[i] = packet_get_string(NULL);
- debug("got kexinit string: %s", cprop[i]);
+ if (options.ciphers != NULL) {
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
}
+ myproposal[PROPOSAL_ENC_ALGS_CTOS] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
+ myproposal[PROPOSAL_ENC_ALGS_STOC] =
+ compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
+
+ if (options.macs != NULL) {
+ 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();
- i = (int) packet_get_char();
- debug("first kex follow == %d", i);
- i = packet_get_int();
- debug("reserved == %d", i);
-
- debug("done read kexinit");
- kex = kex_choose_conf(cprop, sprop, 1);
-
-/* KEXDH */
-
- debug("Wait SSH2_MSG_KEXDH_INIT.");
- packet_read_expect(&payload_len, SSH2_MSG_KEXDH_INIT);
+ /* 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;
- /* key, cert */
- dh_client_pub = BN_new();
- if (dh_client_pub == NULL)
- fatal("dh_client_pub == NULL");
- packet_get_bignum2(dh_client_pub, &dlen);
+ xxx_kex = kex;
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "\ndh_client_pub= ");
- bignum_print(dh_client_pub);
- fprintf(stderr, "\n");
- debug("bits %d", BN_num_bits(dh_client_pub));
-#endif
+ dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
- /* generate DH key */
- dh = new_dh_group1(); /* XXX depends on 'kex' */
+ session_id2 = kex->session_id;
+ session_id2_len = kex->session_id_len;
#ifdef DEBUG_KEXDH
- fprintf(stderr, "\np= ");
- bignum_print(dh->p);
- fprintf(stderr, "\ng= ");
- bignum_print(dh->g);
- fprintf(stderr, "\npub= ");
- bignum_print(dh->pub_key);
- fprintf(stderr, "\n");
-#endif
-
- klen = DH_size(dh);
- kbuf = xmalloc(klen);
- kout = DH_compute_key(kbuf, dh_client_pub, dh);
-
-#ifdef DEBUG_KEXDH
- debug("shared secret: len %d/%d", klen, kout);
- fprintf(stderr, "shared secret == ");
- for (i = 0; i< kout; i++)
- fprintf(stderr, "%02x", (kbuf[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- shared_secret = BN_new();
-
- BN_bin2bn(kbuf, kout, shared_secret);
- memset(kbuf, 0, klen);
- xfree(kbuf);
-
- server_host_key = dsa_get_serverkey(options.dsa_key_file);
- dsa_make_serverkey_blob(server_host_key, &server_host_key_blob, &sbloblen);
-
- /* calc H */ /* XXX depends on 'kex' */
- hash = kex_hash(
- client_version_string,
- server_version_string,
- buffer_ptr(client_kexinit), buffer_len(client_kexinit),
- buffer_ptr(server_kexinit), buffer_len(server_kexinit),
- (char *)server_host_key_blob, sbloblen,
- dh_client_pub,
- dh->pub_key,
- shared_secret
- );
- buffer_free(client_kexinit);
- buffer_free(server_kexinit);
- xfree(client_kexinit);
- xfree(server_kexinit);
-#ifdef DEBUG_KEXDH
- fprintf(stderr, "hash == ");
- for (i = 0; i< 20; i++)
- fprintf(stderr, "%02x", (hash[i])&0xff);
- fprintf(stderr, "\n");
-#endif
- /* sign H */
- dsa_sign(server_host_key, &signature, &slen, hash, 20);
- /* hashlen depends on KEX */
- key_free(server_host_key);
-
- /* send server hostkey, DH pubkey 'f' and singed H */
- packet_start(SSH2_MSG_KEXDH_REPLY);
- packet_put_string((char *)server_host_key_blob, sbloblen);
- packet_put_bignum2(dh->pub_key); // f
- packet_put_string((char *)signature, slen);
- packet_send();
- packet_write_wait();
-
- kex_derive_keys(kex, hash, shared_secret);
- packet_set_kex(kex);
-
- /* have keys, free DH */
- DH_free(dh);
-
- debug("send SSH2_MSG_NEWKEYS.");
- packet_start(SSH2_MSG_NEWKEYS);
- packet_send();
- packet_write_wait();
- debug("done: send SSH2_MSG_NEWKEYS.");
-
- debug("Wait SSH2_MSG_NEWKEYS.");
- packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
- debug("GOT SSH2_MSG_NEWKEYS.");
-
/* send 1st encrypted/maced/compressed message */
packet_start(SSH2_MSG_IGNORE);
packet_put_cstring("markus");
packet_send();
packet_write_wait();
-
- debug("done: KEX2.");
+#endif
+ debug("KEX done");
}
andersk / openssh.git / blobdiff