[gssapi-openssh.git] / openssh / auth2.c

/* $OpenBSD: auth2.c,v 1.120 2008/11/04 08:22:12 djm Exp $ */
/*
 * Copyright (c) 2000 Markus Friedl.  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"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/uio.h>

#include <fcntl.h>
#include <pwd.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>

#include "xmalloc.h"
#include "atomicio.h"
#include "ssh2.h"
#include "packet.h"
#include "log.h"
#include "buffer.h"
#include "servconf.h"
#include "compat.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "dispatch.h"
#include "pathnames.h"
#include "buffer.h"
#include "canohost.h"

#ifdef GSSAPI
#include "ssh-gss.h"
#endif
#include "monitor_wrap.h"

/* import */
extern ServerOptions options;
extern u_char *session_id2;
extern u_int session_id2_len;
extern Buffer loginmsg;

/* methods */

extern Authmethod method_none;
extern Authmethod method_pubkey;
extern Authmethod method_passwd;
extern Authmethod method_kbdint;
extern Authmethod method_hostbased;
#ifdef GSSAPI
extern Authmethod method_gsskeyex;
extern Authmethod method_gssapi;
#endif
#ifdef JPAKE
extern Authmethod method_jpake;
#endif

static int log_flag = 0;


Authmethod *authmethods[] = {
	&method_none,
	&method_pubkey,
#ifdef GSSAPI
	&method_gsskeyex,
	&method_gssapi,
#endif
#ifdef JPAKE
	&method_jpake,
#endif
	&method_passwd,
	&method_kbdint,
	&method_hostbased,
	NULL
};

/* protocol */

static void input_service_request(int, u_int32_t, void *);
static void input_userauth_request(int, u_int32_t, void *);

/* helper */
static Authmethod *authmethod_lookup(const char *);
static char *authmethods_get(void);

char *
auth2_read_banner(void)
{
	struct stat st;
	char *banner = NULL;
	size_t len, n;
	int fd;

	if ((fd = open(options.banner, O_RDONLY)) == -1)
		return (NULL);
	if (fstat(fd, &st) == -1) {
		close(fd);
		return (NULL);
	}
	if (st.st_size > 1*1024*1024) {
		close(fd);
		return (NULL);
	}

	len = (size_t)st.st_size;		/* truncate */
	banner = xmalloc(len + 1);
	n = atomicio(read, fd, banner, len);
	close(fd);

	if (n != len) {
		xfree(banner);
		return (NULL);
	}
	banner[n] = '\0';

	return (banner);
}

void
userauth_send_banner(const char *msg)
{
	if (datafellows & SSH_BUG_BANNER)
		return;

	packet_start(SSH2_MSG_USERAUTH_BANNER);
	packet_put_cstring(msg);
	packet_put_cstring("");		/* language, unused */
	packet_send();
	debug("%s: sent", __func__);
}

static void
userauth_banner(void)
{
	char *banner = NULL;

	if (options.banner == NULL ||
	    strcasecmp(options.banner, "none") == 0 ||
	    (datafellows & SSH_BUG_BANNER) != 0)
		return;

	if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
		goto done;
	userauth_send_banner(banner);

done:
	if (banner)
		xfree(banner);
}

/*
 * loop until authctxt->success == TRUE
 */
void
do_authentication2(Authctxt *authctxt)
{
	dispatch_init(&dispatch_protocol_error);
	dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
	dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
}

/*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_string(&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);
	}
	xfree(service);
}

/*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_string(NULL);
	service = packet_get_string(NULL);
	method = packet_get_string(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", 
		      get_remote_ipaddr(), get_remote_port(), 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();
#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 : "unknown",
		    use_privsep ? " [net]" : "");
		authctxt->service = xstrdup(service);
		authctxt->style = style ? xstrdup(style) : NULL;
		if (use_privsep)
			mm_inform_authserv(service, style);
		userauth_banner();
	} 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;

	/* try to authenticate user */
	m = authmethod_lookup(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);

	xfree(service);
	xfree(user);
	xfree(method);
}

void
userauth_finish(Authctxt *authctxt, int authenticated, char *method)
{
	char *methods;

	if (!authctxt->valid && authenticated)
		fatal("INTERNAL ERROR: authenticated invalid user %s",
		    authctxt->user);

	/* Special handling for root */
	if (authenticated && authctxt->pw->pw_uid == 0 &&
	    !auth_root_allowed(method)) {
		authenticated = 0;
#ifdef SSH_AUDIT_EVENTS
		PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
#endif
	}

#ifdef USE_PAM
	if (options.use_pam && authenticated) {
		if (!PRIVSEP(do_pam_account())) {
			/* if PAM returned a message, send it to the user */
			if (buffer_len(&loginmsg) > 0) {
				buffer_append(&loginmsg, "\0", 1);
				userauth_send_banner(buffer_ptr(&loginmsg));
				packet_write_wait();
			}
			fatal("Access denied for user %s by PAM account "
			    "configuration", authctxt->user);
		}
	}
#endif

#ifdef _UNICOS
	if (authenticated && cray_access_denied(authctxt->user)) {
		authenticated = 0;
		fatal("Access denied for user %s.",authctxt->user);
	}
#endif /* _UNICOS */

	/* Log before sending the reply */
	auth_log(authctxt, authenticated, method, " ssh2");

	if (authctxt->postponed)
		return;

	/* XXX todo: check if multiple auth methods are needed */
	if (authenticated == 1) {
		/* turn off userauth */
		dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
		packet_start(SSH2_MSG_USERAUTH_SUCCESS);
		packet_send();
		packet_write_wait();
		/* now we can break out */
		authctxt->success = 1;
	} else {

		/* Allow initial try of "none" auth without failure penalty */
		if (!authctxt->server_caused_failure &&
		    (authctxt->attempt > 1 || strcmp(method, "none") != 0))
			authctxt->failures++;
		if (authctxt->failures >= options.max_authtries) {
#ifdef SSH_AUDIT_EVENTS
			PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
#endif
			packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
		}
		methods = authmethods_get();
		packet_start(SSH2_MSG_USERAUTH_FAILURE);
		packet_put_cstring(methods);
		packet_put_char(0);	/* XXX partial success, unused */
		packet_send();
		packet_write_wait();
		xfree(methods);
	}
}

static char *
authmethods_get(void)
{
	Buffer b;
	char *list;
	int i;

	buffer_init(&b);
	for (i = 0; authmethods[i] != NULL; i++) {
		if (strcmp(authmethods[i]->name, "none") == 0)
			continue;
		if (authmethods[i]->enabled != NULL &&
		    *(authmethods[i]->enabled) != 0) {
			if (buffer_len(&b) > 0)
				buffer_append(&b, ",", 1);
			buffer_append(&b, authmethods[i]->name,
			    strlen(authmethods[i]->name));
		}
	}
	buffer_append(&b, "\0", 1);
	list = xstrdup(buffer_ptr(&b));
	buffer_free(&b);
	return list;
}

static Authmethod *
authmethod_lookup(const char *name)
{
	int i;

	if (name != NULL)
		for (i = 0; authmethods[i] != NULL; i++)
			if (authmethods[i]->enabled != NULL &&
			    *(authmethods[i]->enabled) != 0 &&
			    strcmp(name, authmethods[i]->name) == 0)
				return authmethods[i];
	debug2("Unrecognized authentication method name: %s",
	    name ? name : "NULL");
	return NULL;
}
Commit	Line	Data
91d9cdd3	1	/* $OpenBSD: auth2.c,v 1.120 2008/11/04 08:22:12 djm Exp $ */
3c0ef626	2	/*
	3	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	15	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	16	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	17	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	18	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	19	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	20	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	21	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	22	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	23	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	24	*/
	25
	26	#include "includes.h"
3c0ef626	27
9108f8d9	28	#include <sys/types.h>
22616013	29	#include <sys/stat.h>
22616013	30	#include <sys/uio.h>
9108f8d9	31
22616013	32	#include <fcntl.h>
9108f8d9	33	#include <pwd.h>
	34	#include <stdarg.h>
	35	#include <string.h>
22616013	36	#include <unistd.h>
9108f8d9	37
3c0ef626	38	#include "xmalloc.h"
22616013	39	#include "atomicio.h"
9108f8d9	40	#include "ssh2.h"
3c0ef626	41	#include "packet.h"
3c0ef626	42	#include "log.h"
9108f8d9	43	#include "buffer.h"
3c0ef626	44	#include "servconf.h"
3c0ef626	45	#include "compat.h"
9108f8d9	46	#include "key.h"
9108f8d9	47	#include "hostfile.h"
3c0ef626	48	#include "auth.h"
3c0ef626	49	#include "dispatch.h"
3c0ef626	50	#include "pathnames.h"
996d5e62	51	#include "buffer.h"
76d45d2f	52	#include "canohost.h"
3c0ef626	53
0fff78ff	54	#ifdef GSSAPI
	55	#include "ssh-gss.h"
	56	#endif
9108f8d9	57	#include "monitor_wrap.h"
0fff78ff	58
3c0ef626	59	/* import */
	60	extern ServerOptions options;
	61	extern u_char *session_id2;
0fff78ff	62	extern u_int session_id2_len;
996d5e62	63	extern Buffer loginmsg;
3c0ef626	64
f5799ae1	65	/* methods */
	66
	67	extern Authmethod method_none;
	68	extern Authmethod method_pubkey;
	69	extern Authmethod method_passwd;
	70	extern Authmethod method_kbdint;
	71	extern Authmethod method_hostbased;
0fff78ff	72	#ifdef GSSAPI
f97edba6	73	extern Authmethod method_gsskeyex;
0fff78ff	74	extern Authmethod method_gssapi;
0fff78ff	75	#endif
91d9cdd3	76	#ifdef JPAKE
	77	extern Authmethod method_jpake;
	78	#endif
f5799ae1	79
76d45d2f	80	static int log_flag = 0;
	81
	82
f5799ae1	83	Authmethod *authmethods[] = {
	84	&method_none,
	85	&method_pubkey,
0fff78ff	86	#ifdef GSSAPI
f97edba6	87	&method_gsskeyex,
0fff78ff	88	&method_gssapi,
91d9cdd3	89	#endif
	90	#ifdef JPAKE
	91	&method_jpake,
0fff78ff	92	#endif
f5799ae1	93	&method_passwd,
	94	&method_kbdint,
	95	&method_hostbased,
	96	NULL
3c0ef626	97	};
	98
	99	/* protocol */
	100
e9a17296	101	static void input_service_request(int, u_int32_t, void *);
e9a17296	102	static void input_userauth_request(int, u_int32_t, void *);
3c0ef626	103
	104	/* helper */
	105	static Authmethod authmethod_lookup(const char );
	106	static char *authmethods_get(void);
3c0ef626	107
22616013	108	char *
	109	auth2_read_banner(void)
	110	{
	111	struct stat st;
	112	char *banner = NULL;
	113	size_t len, n;
	114	int fd;
	115
	116	if ((fd = open(options.banner, O_RDONLY)) == -1)
	117	return (NULL);
	118	if (fstat(fd, &st) == -1) {
	119	close(fd);
	120	return (NULL);
	121	}
	122	if (st.st_size > 110241024) {
	123	close(fd);
	124	return (NULL);
	125	}
	126
	127	len = (size_t)st.st_size; /* truncate */
	128	banner = xmalloc(len + 1);
	129	n = atomicio(read, fd, banner, len);
	130	close(fd);
	131
	132	if (n != len) {
	133	xfree(banner);
	134	return (NULL);
	135	}
	136	banner[n] = '\0';
	137
	138	return (banner);
	139	}
	140
	141	void
	142	userauth_send_banner(const char *msg)
	143	{
	144	if (datafellows & SSH_BUG_BANNER)
	145	return;
	146
	147	packet_start(SSH2_MSG_USERAUTH_BANNER);
	148	packet_put_cstring(msg);
	149	packet_put_cstring(""); /* language, unused */
	150	packet_send();
	151	debug("%s: sent", __func__);
	152	}
	153
	154	static void
	155	userauth_banner(void)
	156	{
	157	char *banner = NULL;
	158
	159	if (options.banner == NULL \|\|
	160	strcasecmp(options.banner, "none") == 0 \|\|
	161	(datafellows & SSH_BUG_BANNER) != 0)
	162	return;
	163
	164	if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
	165	goto done;
	166	userauth_send_banner(banner);
	167
	168	done:
	169	if (banner)
	170	xfree(banner);
	171	}
172
3c0ef626	173	/*
	174	* loop until authctxt->success == TRUE
	175	*/
cdd66111	176	void
cdd66111	177	do_authentication2(Authctxt *authctxt)
3c0ef626	178	{
e9a17296	179	dispatch_init(&dispatch_protocol_error);
3c0ef626	180	dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
3c0ef626	181	dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
3c0ef626	182	}
3c0ef626	183
9108f8d9	184	/ARGSUSED/
3c0ef626	185	static void
e9a17296	186	input_service_request(int type, u_int32_t seq, void *ctxt)
3c0ef626	187	{
	188	Authctxt *authctxt = ctxt;
	189	u_int len;
41b2f314	190	int acceptit = 0;
3c0ef626	191	char *service = packet_get_string(&len);
e9a17296	192	packet_check_eom();
3c0ef626	193
	194	if (authctxt == NULL)
	195	fatal("input_service_request: no authctxt");
	196
	197	if (strcmp(service, "ssh-userauth") == 0) {
	198	if (!authctxt->success) {
41b2f314	199	acceptit = 1;
3c0ef626	200	/* now we can handle user-auth requests */
	201	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
	202	}
	203	}
	204	/* XXX all other service requests are denied */
	205
41b2f314	206	if (acceptit) {
3c0ef626	207	packet_start(SSH2_MSG_SERVICE_ACCEPT);
	208	packet_put_cstring(service);
	209	packet_send();
	210	packet_write_wait();
	211	} else {
	212	debug("bad service request %s", service);
	213	packet_disconnect("bad service request %s", service);
	214	}
	215	xfree(service);
	216	}
	217
9108f8d9	218	/ARGSUSED/
3c0ef626	219	static void
e9a17296	220	input_userauth_request(int type, u_int32_t seq, void *ctxt)
3c0ef626	221	{
	222	Authctxt *authctxt = ctxt;
	223	Authmethod *m = NULL;
	224	char user, service, method, style = NULL;
	225	int authenticated = 0;
	226
	227	if (authctxt == NULL)
	228	fatal("input_userauth_request: no authctxt");
	229
	230	user = packet_get_string(NULL);
	231	service = packet_get_string(NULL);
	232	method = packet_get_string(NULL);
	233	debug("userauth-request for user %s service %s method %s", user, service, method);
76d45d2f	234	if (!log_flag) {
	235	logit("SSH: Server;Ltype: Authname;Remote: %s-%d;Name: %s",
	236	get_remote_ipaddr(), get_remote_port(), user);
	237	log_flag = 1;
	238	}
3c0ef626	239	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
	240
	241	if ((style = strchr(user, ':')) != NULL)
	242	*style++ = 0;
	243
	244	if (authctxt->attempt++ == 0) {
	245	/* setup auth context */
700318f3	246	authctxt->pw = PRIVSEP(getpwnamallow(user));
99be0775	247	authctxt->user = xstrdup(user);
700318f3	248	if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
3c0ef626	249	authctxt->valid = 1;
3c0ef626	250	debug2("input_userauth_request: setting up authctxt for %s", user);
3c0ef626	251	} else {
c9f39d2c	252	logit("input_userauth_request: invalid user %s", user);
0fff78ff	253	authctxt->pw = fakepw();
996d5e62	254	#ifdef SSH_AUDIT_EVENTS
996d5e62	255	PRIVSEP(audit_event(SSH_INVALID_USER));
3c0ef626	256	#endif
3c0ef626	257	}
2c06c99b	258	#ifdef USE_PAM
	259	if (options.use_pam)
	260	PRIVSEP(start_pam(authctxt));
	261	#endif
c9f39d2c	262	setproctitle("%s%s", authctxt->valid ? user : "unknown",
700318f3	263	use_privsep ? " [net]" : "");
3c0ef626	264	authctxt->service = xstrdup(service);
3c0ef626	265	authctxt->style = style ? xstrdup(style) : NULL;
700318f3	266	if (use_privsep)
700318f3	267	mm_inform_authserv(service, style);
22616013	268	userauth_banner();
3c0ef626	269	} else if (strcmp(user, authctxt->user) != 0 \|\|
	270	strcmp(service, authctxt->service) != 0) {
	271	packet_disconnect("Change of username or service not allowed: "
	272	"(%s,%s) -> (%s,%s)",
	273	authctxt->user, authctxt->service, user, service);
	274	}
	275	/* reset state */
e9a17296	276	auth2_challenge_stop(authctxt);
91d9cdd3	277	#ifdef JPAKE
	278	auth2_jpake_stop(authctxt);
	279	#endif
0fff78ff	280
0fff78ff	281	#ifdef GSSAPI
91d9cdd3	282	/* XXX move to auth2_gssapi_stop() */
0fff78ff	283	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	284	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	285	#endif
	286
3c0ef626	287	authctxt->postponed = 0;
f97edba6	288	authctxt->server_caused_failure = 0;
3c0ef626	289
	290	/* try to authenticate user */
	291	m = authmethod_lookup(method);
22616013	292	if (m != NULL && authctxt->failures < options.max_authtries) {
3c0ef626	293	debug2("input_userauth_request: try method %s", method);
	294	authenticated = m->userauth(authctxt);
	295	}
	296	userauth_finish(authctxt, authenticated, method);
	297
	298	xfree(service);
	299	xfree(user);
	300	xfree(method);
	301	}
	302
	303	void
	304	userauth_finish(Authctxt authctxt, int authenticated, char method)
	305	{
	306	char *methods;
	307
	308	if (!authctxt->valid && authenticated)
	309	fatal("INTERNAL ERROR: authenticated invalid user %s",
	310	authctxt->user);
	311
	312	/* Special handling for root */
6a9b3198	313	if (authenticated && authctxt->pw->pw_uid == 0 &&
996d5e62	314	!auth_root_allowed(method)) {
3c0ef626	315	authenticated = 0;
996d5e62	316	#ifdef SSH_AUDIT_EVENTS
	317	PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
	318	#endif
	319	}
3c0ef626	320
3c0ef626	321	#ifdef USE_PAM
996d5e62	322	if (options.use_pam && authenticated) {
	323	if (!PRIVSEP(do_pam_account())) {
	324	/* if PAM returned a message, send it to the user */
	325	if (buffer_len(&loginmsg) > 0) {
	326	buffer_append(&loginmsg, "\0", 1);
	327	userauth_send_banner(buffer_ptr(&loginmsg));
	328	packet_write_wait();
	329	}
	330	fatal("Access denied for user %s by PAM account "
665a873d	331	"configuration", authctxt->user);
996d5e62	332	}
996d5e62	333	}
0fff78ff	334	#endif
3c0ef626	335
41b2f314	336	#ifdef _UNICOS
	337	if (authenticated && cray_access_denied(authctxt->user)) {
	338	authenticated = 0;
	339	fatal("Access denied for user %s.",authctxt->user);
	340	}
	341	#endif /* _UNICOS */
	342
3c0ef626	343	/* Log before sending the reply */
	344	auth_log(authctxt, authenticated, method, " ssh2");
	345
	346	if (authctxt->postponed)
	347	return;
	348
	349	/* XXX todo: check if multiple auth methods are needed */
	350	if (authenticated == 1) {
	351	/* turn off userauth */
e9a17296	352	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
3c0ef626	353	packet_start(SSH2_MSG_USERAUTH_SUCCESS);
	354	packet_send();
	355	packet_write_wait();
	356	/* now we can break out */
	357	authctxt->success = 1;
	358	} else {
22616013	359
22616013	360	/* Allow initial try of "none" auth without failure penalty */
f97edba6	361	if (!authctxt->server_caused_failure &&
f97edba6	362	(authctxt->attempt > 1 \|\| strcmp(method, "none") != 0))
22616013	363	authctxt->failures++;
22616013	364	if (authctxt->failures >= options.max_authtries) {
996d5e62	365	#ifdef SSH_AUDIT_EVENTS
	366	PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
	367	#endif
3c0ef626	368	packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
996d5e62	369	}
3c0ef626	370	methods = authmethods_get();
	371	packet_start(SSH2_MSG_USERAUTH_FAILURE);
	372	packet_put_cstring(methods);
	373	packet_put_char(0); /* XXX partial success, unused */
	374	packet_send();
	375	packet_write_wait();
	376	xfree(methods);
	377	}
	378	}
	379
3c0ef626	380	static char *
	381	authmethods_get(void)
	382	{
e9a17296	383	Buffer b;
3c0ef626	384	char *list;
f5799ae1	385	int i;
3c0ef626	386
e9a17296	387	buffer_init(&b);
f5799ae1	388	for (i = 0; authmethods[i] != NULL; i++) {
f5799ae1	389	if (strcmp(authmethods[i]->name, "none") == 0)
3c0ef626	390	continue;
f5799ae1	391	if (authmethods[i]->enabled != NULL &&
f5799ae1	392	*(authmethods[i]->enabled) != 0) {
e9a17296	393	if (buffer_len(&b) > 0)
e9a17296	394	buffer_append(&b, ",", 1);
f5799ae1	395	buffer_append(&b, authmethods[i]->name,
f5799ae1	396	strlen(authmethods[i]->name));
3c0ef626	397	}
3c0ef626	398	}
e9a17296	399	buffer_append(&b, "\0", 1);
	400	list = xstrdup(buffer_ptr(&b));
	401	buffer_free(&b);
3c0ef626	402	return list;
	403	}
	404
	405	static Authmethod *
	406	authmethod_lookup(const char *name)
	407	{
f5799ae1	408	int i;
f5799ae1	409
3c0ef626	410	if (name != NULL)
f5799ae1	411	for (i = 0; authmethods[i] != NULL; i++)
	412	if (authmethods[i]->enabled != NULL &&
	413	*(authmethods[i]->enabled) != 0 &&
	414	strcmp(name, authmethods[i]->name) == 0)
	415	return authmethods[i];
	416	debug2("Unrecognized authentication method name: %s",
	417	name ? name : "NULL");
3c0ef626	418	return NULL;
3c0ef626	419	}
22616013	420