*/
#include "includes.h"
-RCSID("$OpenBSD: sshd.c,v 1.263 2003/02/16 17:09:57 markus Exp $");
+RCSID("$OpenBSD: sshd.c,v 1.290 2004/03/11 10:21:17 markus Exp $");
#include <openssl/dh.h>
#include <openssl/bn.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;
/* variables used for privilege separation */
int use_privsep;
-struct monitor *pmonitor;
+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);
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],
+ logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
strerror(errno));
exit(1);
}
{
/* XXX no idea how fix this signal handler */
+ 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());
}
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 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) {
- 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) {
- log("probed from %s with %s. Don't panic.",
+ logit("probed from %s with %s. Don't panic.",
get_remote_ipaddr(), client_version_string);
- fatal_cleanup();
+ 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);
}
}
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 */
+ /* XXX not ready, too heavy after chroot */
do_setusercontext(pw);
#else
gidset[0] = pw->pw_gid;
- if (setgid(pw->pw_gid) < 0)
- fatal("setgid failed for %u", pw->pw_gid );
if (setgroups(1, gidset) < 0)
fatal("setgroups: %.100s", strerror(errno));
permanently_set_uid(pw);
#endif
}
-static Authctxt *
-privsep_preauth(void)
+static int
+privsep_preauth(Authctxt *authctxt)
{
- Authctxt *authctxt = NULL;
int status;
pid_t pid;
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);
+ pmonitor->m_pid = pid;
+ monitor_child_preauth(authctxt, pmonitor);
close(pmonitor->m_sendfd);
/* Sync memory */
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);
+ return (1);
} else {
/* child */
privsep_preauth_child();
setproctitle("%s", "[net]");
}
- return (NULL);
+ return (0);
}
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 (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);
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;
}
Key *
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");
+ fprintf(stderr, "%s, %s\n",
+ SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
+ fprintf(stderr,
+"usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n"
+" [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n"
+ );
exit(1);
}
FILE *f;
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;
#ifdef HAVE_SECUREWARE
(void)set_auth_parameters(ac, av);
#endif
- __progname = get_progname(av[0]);
+ __progname = ssh_get_progname(av[0]);
init_rng();
/* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
saved_argc = ac;
- saved_argv = av;
- saved_argv = xmalloc(sizeof(*saved_argv) * 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
+ if (geteuid() == 0 && setgroups(0, NULL) == -1)
+ debug("setgroups(): %.200s", strerror(errno));
+
/* 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;
}
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_FACILITY_AUTH : options.log_facility,
log_stderr || !inetd_flag);
+#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!
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;
}
#ifndef GSSAPI
/* The GSSAPI key exchange can run without a host key */
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;
}
#endif
if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
- log("sshd: no hostkeys available -- exiting.");
+ logit("sshd: no hostkeys available -- exiting.");
exit(1);
}
if (test_flag)
exit(0);
-#ifdef GSSAPI
- ssh_gssapi_clean_env();
-#endif /* GSSAPI */
-
/*
* 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
+ * 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)
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));
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) {
+ 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);
}
/* 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(STREAMS_PUSH_ACQUIRES_CTTY)
+#if !defined(SSHD_ACQUIRES_CTTY)
/*
- * If setsid is called on Solaris, sshd will acquire the controlling
- * terminal while pushing STREAMS modules. This will prevent the
- * shell from acquiring it later.
+ * 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));
signal(SIGCHLD, SIG_DFL);
signal(SIGINT, SIG_DFL);
- /* 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 privileged
- * programs. Of course, if the intruder has root access on his local
- * machine, he can connect from any port. So do not use these
- * authentication methods from machines that you do not trust.
- */
- 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 */
-#if defined(AFS) || defined(AFS_KRB5)
+#if defined(AFS_KRB5)
/* If machine has AFS, set process authentication group. */
if (k_hasafs()) {
k_setpag();
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 ((authctxt = privsep_preauth()) != NULL)
+ 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
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();
/* 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
-#ifdef GSSAPI
- if (options.gss_authentication)
- auth_mask |= 1 << SSH_AUTH_GSSAPI;
-#endif
if (options.challenge_response_authentication == 1)
auth_mask |= 1 << SSH_AUTH_TIS;
if (options.password_authentication)
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];
}
-
-#ifdef GSSAPI
- /*
- * Before we destroy the host and server keys, hash them so we can
- * send the hash over to the client via a secure channel so that it
- * can verify them.
- */
- {
- MD5_CTX md5context;
- Buffer buf;
- unsigned char *data;
- unsigned int data_len;
- extern unsigned char ssh1_key_digest[16]; /* in gss-genr.c */
-
-
- debug("Calculating MD5 hash of server and host keys...");
-
- /* Write all the keys to a temporary buffer */
- buffer_init(&buf);
-
- /* Server key */
- buffer_put_bignum(&buf, sensitive_data.server_key->rsa->e);
- buffer_put_bignum(&buf, sensitive_data.server_key->rsa->n);
-
- /* Host key */
- buffer_put_bignum(&buf, sensitive_data.ssh1_host_key->rsa->e);
- buffer_put_bignum(&buf, sensitive_data.ssh1_host_key->rsa->n);
-
- /* Get the resulting data */
- data = (unsigned char *) buffer_ptr(&buf);
- data_len = buffer_len(&buf);
-
- /* And hash it */
- MD5_Init(&md5context);
- MD5_Update(&md5context, data, data_len);
- MD5_Final(ssh1_key_digest, &md5context);
-
- /* Clean up */
- buffer_clear(&buf);
- buffer_free(&buf);
- }
-#endif /* GSSAPI */
-
/* Destroy the private and public keys. No longer. */
destroy_sensitive_data();
orig= NULL;
if (options.gss_keyex)
- gss = ssh_server_gssapi_mechanisms();
+ gss = ssh_gssapi_server_mechanisms();
else
gss = NULL;
#endif
debug("KEX done");
}
+
+/* server specific fatal cleanup */
+void
+cleanup_exit(int i)
+{
+ if (the_authctxt)
+ do_cleanup(the_authctxt);
+ _exit(i);
+}
andersk / gssapi-openssh.git / blobdiff