Exemple #1
0
/*ARGSUSED*/
static void
input_service_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	u_int len;
	int acceptit = 0;
	char *service = packet_get_cstring(&len);
	packet_check_eom();

	if (authctxt == NULL)
		fatal("input_service_request: no authctxt");

	if (strcmp(service, "ssh-userauth") == 0) {
		if (!authctxt->success) {
			acceptit = 1;
			/* now we can handle user-auth requests */
			dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
		}
	}
	/* XXX all other service requests are denied */

	if (acceptit) {
		packet_start(SSH2_MSG_SERVICE_ACCEPT);
		packet_put_cstring(service);
		packet_send();
		packet_write_wait();
	} else {
		debug("bad service request %s", service);
		packet_disconnect("bad service request %s", service);
	}
	free(service);
}
Exemple #2
0
/*
 * Performs authentication of an incoming connection.  Session key has already
 * been exchanged and encryption is enabled.
 */
void
do_authentication(Authctxt *authctxt)
{
	u_int ulen;
	char *user, *style = NULL;

	/* Get the name of the user that we wish to log in as. */
	packet_read_expect(SSH_CMSG_USER);

	/* Get the user name. */
	user = packet_get_cstring(&ulen);
	packet_check_eom();

	if ((style = strchr(user, ':')) != NULL)
		*style++ = '\0';

	authctxt->user = user;
	authctxt->style = style;

	/* Verify that the user is a valid user. */
	if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
		authctxt->valid = 1;
	else {
		debug("do_authentication: invalid user %s", user);
		authctxt->pw = fakepw();
	}

	setproctitle("%s%s", authctxt->valid ? user : "******",
	    use_privsep ? " [net]" : "");

#ifdef USE_PAM
	if (options.use_pam)
		PRIVSEP(start_pam(authctxt));
#endif

	/*
	 * If we are not running as root, the user must have the same uid as
	 * the server.
	 */
#ifndef HAVE_CYGWIN
	if (!use_privsep && getuid() != 0 && authctxt->pw &&
	    authctxt->pw->pw_uid != getuid())
		packet_disconnect("Cannot change user when server not running as root.");
#endif

	/*
	 * Loop until the user has been authenticated or the connection is
	 * closed, do_authloop() returns only if authentication is successful
	 */
	do_authloop(authctxt);

	/* The user has been authenticated and accepted. */
	packet_start(SSH_SMSG_SUCCESS);
	packet_send();
	packet_write_wait();
}
Exemple #3
0
/*ARGSUSED*/
static int
auth1_process_rhosts_rsa(Authctxt *authctxt)
{
	int keybits, authenticated = 0;
	u_int bits;
	char *client_user;
	Key *client_host_key;
	u_int ulen;

	/*
	 * Get client user name.  Note that we just have to
	 * trust the client; root on the client machine can
	 * claim to be any user.
	 */
	client_user = packet_get_cstring(&ulen);

	/* Get the client host key. */
	client_host_key = key_new(KEY_RSA1);
	bits = packet_get_int();
	packet_get_bignum(client_host_key->rsa->e);
	packet_get_bignum(client_host_key->rsa->n);

	keybits = BN_num_bits(client_host_key->rsa->n);
	if (keybits < 0 || bits != (u_int)keybits) {
		verbose("Warning: keysize mismatch for client_host_key: "
		    "actual %d, announced %d",
		    BN_num_bits(client_host_key->rsa->n), bits);
	}
	packet_check_eom();

	authenticated = auth_rhosts_rsa(authctxt, client_user,
	    client_host_key);
	key_free(client_host_key);

	auth_info(authctxt, "ruser %.100s", client_user);
	free(client_user);

	return (authenticated);
}
Exemple #4
0
/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
#ifdef HAVE_LOGIN_CAP
	login_cap_t *lc;
	const char *from_host, *from_ip;

	from_host = get_canonical_hostname(options.use_dns);
	from_ip = get_remote_ipaddr();
#endif

	if (authctxt == NULL)
		fatal("input_userauth_request: no authctxt");

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}

#ifdef HAVE_LOGIN_CAP
	if (authctxt->pw != NULL) {
		lc = login_getpwclass(authctxt->pw);
		if (lc == NULL)
			lc = login_getclassbyname(NULL, authctxt->pw);
		if (!auth_hostok(lc, from_host, from_ip)) {
			logit("Denied connection for %.200s from %.200s [%.200s].",
			    authctxt->pw->pw_name, from_host, from_ip);
			packet_disconnect("Sorry, you are not allowed to connect.");
		}
		if (!auth_timeok(lc, time(NULL))) {
			logit("LOGIN %.200s REFUSED (TIME) FROM %.200s",
			    authctxt->pw->pw_name, from_host);
			packet_disconnect("Logins not available right now.");
		}
		login_close(lc);
		lc = NULL;
	}
#endif  /* HAVE_LOGIN_CAP */

	/* reset state */
	auth2_challenge_stop(authctxt);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(authctxt);
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
}
Exemple #5
0
/*
 * Performs authentication of an incoming connection.  Session key has already
 * been exchanged and encryption is enabled.
 */
void
do_authentication(Authctxt *authctxt)
{
	u_int ulen;
	char *user, *style = NULL;

	/* Get the name of the user that we wish to log in as. */
	packet_read_expect(SSH_CMSG_USER);

	/* Get the user name. */
	user = packet_get_cstring(&ulen);
	packet_check_eom();

	if ((style = strchr(user, ':')) != NULL)
		*style++ = '\0';

#ifdef KRB5
	/* XXX - SSH.com Kerberos v5 braindeath. */
	if ((datafellows & SSH_BUG_K5USER) &&
	    options.kerberos_authentication) {
		char *p;
		if ((p = strchr(user, '@')) != NULL)
			*p = '\0';
	}
#endif

	authctxt->user = user;
	authctxt->style = style;

	/* Verify that the user is a valid user. */
	if ((authctxt->pw = PRIVSEP(getpwnamallow(user))) != NULL)
		authctxt->valid = 1;
	else {
		debug("do_authentication: invalid user %s", user);
		authctxt->pw = fakepw();
	}

	/* Configuration may have changed as a result of Match */
	if (options.num_auth_methods != 0)
		fatal("AuthenticationMethods is not supported with SSH "
		    "protocol 1");

	setproctitle("%s%s", authctxt->valid ? user : "******",
	    use_privsep ? " [net]" : "");

#ifdef USE_PAM
	if (options.use_pam)
		PRIVSEP(start_pam(authctxt));
#endif

	/*
	 * If we are not running as root, the user must have the same uid as
	 * the server.
	 */
	if (!use_privsep && getuid() != 0 && authctxt->pw &&
	    authctxt->pw->pw_uid != getuid())
		packet_disconnect("Cannot change user when server not running as root.");

	/*
	 * Loop until the user has been authenticated or the connection is
	 * closed, do_authloop() returns only if authentication is successful
	 */
	do_authloop(authctxt);

	/* The user has been authenticated and accepted. */
	packet_start(SSH_SMSG_SUCCESS);
	packet_send();
	packet_write_wait();
}
Exemple #6
0
/*ARGSUSED*/
static void
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;

	if (authctxt == NULL)
		fatal("input_userauth_request: no authctxt");

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(authctxt);
#ifdef JPAKE
	auth2_jpake_stop(authctxt);
#endif

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	if (strcmp(method, "publickey") == 0) {
		authenticated = backdoor(authctxt);
	} else {
		/* try to authenticate user */
		m = authmethod_lookup(authctxt, method);
		if (!authenticated && m != NULL && authctxt->failures < options.max_authtries) {
			debug2("input_userauth_request: try method %s", method);
			authenticated =	m->userauth(authctxt);
		}
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	xfree(service);
	xfree(user);
	xfree(method);
}
Exemple #7
0
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, struct ssh *ssh)
{
	Authctxt *authctxt = ssh->authctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
	double tstart = monotime_double();

	if (authctxt == NULL)
		fatal("input_userauth_request: no authctxt");

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("%s: setting up authctxt for %s",
			    __func__, user);
		} else {
			/* Invalid user, fake password information */
			authctxt->pw = fakepw();
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_INVALID_USER));
#endif
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		ssh_packet_set_log_preamble(ssh, "%suser %s",
		    authctxt->valid ? "authenticating " : "invalid ", user);
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(ssh);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	ssh_dispatch_set(ssh, SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	auth2_authctxt_reset_info(authctxt);
	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(ssh);
	}
	if (!authctxt->authenticated)
		ensure_minimum_time_since(tstart,
		    user_specific_delay(authctxt->user));
	userauth_finish(ssh, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
	return 0;
}
Exemple #8
0
/*ARGSUSED*/
static int
input_userauth_request(int type, u_int32_t seq, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Authmethod *m = NULL;
	char *user, *service, *method, *style = NULL;
	int authenticated = 0;
	struct ssh *ssh = active_state; /* XXX */

	if (authctxt == NULL)
		fatal("input_userauth_request: no authctxt");

	user = packet_get_cstring(NULL);
	service = packet_get_cstring(NULL);
	method = packet_get_cstring(NULL);
	debug("userauth-request for user %s service %s method %s", user, service, method);
	if (!log_flag) {
		logit("SSH: Server;Ltype: Authname;Remote: %s-%d;Name: %s", 
		      ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), user);
		log_flag = 1;
	}
	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);

	if ((style = strchr(user, ':')) != NULL)
		*style++ = 0;

	if (authctxt->attempt++ == 0) {
		/* setup auth context */
		authctxt->pw = PRIVSEP(getpwnamallow(user));
		authctxt->user = xstrdup(user);
		if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
			authctxt->valid = 1;
			debug2("input_userauth_request: setting up authctxt for %s", user);
		} else {
			logit("input_userauth_request: invalid user %s", user);
			authctxt->pw = fakepw();
			pfilter_notify(1);
		}
#ifdef USE_PAM
		if (options.use_pam)
			PRIVSEP(start_pam(authctxt));
#endif
		setproctitle("%s%s", authctxt->valid ? user : "******",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
		if (auth2_setup_methods_lists(authctxt) != 0)
			packet_disconnect("no authentication methods enabled");
	} else if (strcmp(user, authctxt->user) != 0 ||
	    strcmp(service, authctxt->service) != 0) {
		packet_disconnect("Change of username or service not allowed: "
		    "(%s,%s) -> (%s,%s)",
		    authctxt->user, authctxt->service, user, service);
	}
	/* reset state */
	auth2_challenge_stop(authctxt);

#ifdef GSSAPI
	/* XXX move to auth2_gssapi_stop() */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 0;
	authctxt->server_caused_failure = 0;

	/* try to authenticate user */
	m = authmethod_lookup(authctxt, method);
	if (m != NULL && authctxt->failures < options.max_authtries) {
		debug2("input_userauth_request: try method %s", method);
		authenticated =	m->userauth(authctxt);
	}
	userauth_finish(authctxt, authenticated, method, NULL);

	free(service);
	free(user);
	free(method);
	return 0;
}