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

/* $OpenBSD: auth2.c,v 1.119 2008/07/04 23:30:16 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_gssapi;
#endif

static int log_flag = 0;


Authmethod *authmethods[] = {
	&method_none,
	&method_pubkey,
#ifdef GSSAPI
	&method_gssapi,
#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 GSSAPI
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
#endif

	authctxt->postponed = 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->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
22616013	1	/* $OpenBSD: auth2.c,v 1.119 2008/07/04 23:30:16 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"
c015d727	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
	73	extern Authmethod method_gssapi;
	74	#endif
f5799ae1	75
c015d727	76	static int log_flag = 0;
	77
	78
f5799ae1	79	Authmethod *authmethods[] = {
	80	&method_none,
	81	&method_pubkey,
0fff78ff	82	#ifdef GSSAPI
	83	&method_gssapi,
	84	#endif
f5799ae1	85	&method_passwd,
	86	&method_kbdint,
	87	&method_hostbased,
	88	NULL
3c0ef626	89	};
	90
	91	/* protocol */
	92
e9a17296	93	static void input_service_request(int, u_int32_t, void *);
e9a17296	94	static void input_userauth_request(int, u_int32_t, void *);
3c0ef626	95
	96	/* helper */
	97	static Authmethod authmethod_lookup(const char );
	98	static char *authmethods_get(void);
3c0ef626	99
22616013	100	char *
	101	auth2_read_banner(void)
	102	{
	103	struct stat st;
	104	char *banner = NULL;
	105	size_t len, n;
	106	int fd;
	107
	108	if ((fd = open(options.banner, O_RDONLY)) == -1)
	109	return (NULL);
	110	if (fstat(fd, &st) == -1) {
	111	close(fd);
	112	return (NULL);
	113	}
	114	if (st.st_size > 110241024) {
	115	close(fd);
	116	return (NULL);
	117	}
	118
	119	len = (size_t)st.st_size; /* truncate */
	120	banner = xmalloc(len + 1);
	121	n = atomicio(read, fd, banner, len);
	122	close(fd);
	123
	124	if (n != len) {
	125	xfree(banner);
	126	return (NULL);
	127	}
	128	banner[n] = '\0';
	129
	130	return (banner);
	131	}
	132
	133	void
	134	userauth_send_banner(const char *msg)
	135	{
	136	if (datafellows & SSH_BUG_BANNER)
	137	return;
	138
	139	packet_start(SSH2_MSG_USERAUTH_BANNER);
	140	packet_put_cstring(msg);
	141	packet_put_cstring(""); /* language, unused */
	142	packet_send();
	143	debug("%s: sent", __func__);
	144	}
	145
	146	static void
	147	userauth_banner(void)
	148	{
	149	char *banner = NULL;
	150
	151	if (options.banner == NULL \|\|
	152	strcasecmp(options.banner, "none") == 0 \|\|
	153	(datafellows & SSH_BUG_BANNER) != 0)
	154	return;
	155
	156	if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
	157	goto done;
	158	userauth_send_banner(banner);
	159
	160	done:
	161	if (banner)
	162	xfree(banner);
	163	}
164
3c0ef626	165	/*
	166	* loop until authctxt->success == TRUE
	167	*/
cdd66111	168	void
cdd66111	169	do_authentication2(Authctxt *authctxt)
3c0ef626	170	{
e9a17296	171	dispatch_init(&dispatch_protocol_error);
3c0ef626	172	dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
3c0ef626	173	dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
3c0ef626	174	}
3c0ef626	175
9108f8d9	176	/ARGSUSED/
3c0ef626	177	static void
e9a17296	178	input_service_request(int type, u_int32_t seq, void *ctxt)
3c0ef626	179	{
	180	Authctxt *authctxt = ctxt;
	181	u_int len;
41b2f314	182	int acceptit = 0;
3c0ef626	183	char *service = packet_get_string(&len);
e9a17296	184	packet_check_eom();
3c0ef626	185
	186	if (authctxt == NULL)
	187	fatal("input_service_request: no authctxt");
	188
	189	if (strcmp(service, "ssh-userauth") == 0) {
	190	if (!authctxt->success) {
41b2f314	191	acceptit = 1;
3c0ef626	192	/* now we can handle user-auth requests */
	193	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
	194	}
	195	}
	196	/* XXX all other service requests are denied */
	197
41b2f314	198	if (acceptit) {
3c0ef626	199	packet_start(SSH2_MSG_SERVICE_ACCEPT);
	200	packet_put_cstring(service);
	201	packet_send();
	202	packet_write_wait();
	203	} else {
	204	debug("bad service request %s", service);
	205	packet_disconnect("bad service request %s", service);
	206	}
	207	xfree(service);
	208	}
	209
9108f8d9	210	/ARGSUSED/
3c0ef626	211	static void
e9a17296	212	input_userauth_request(int type, u_int32_t seq, void *ctxt)
3c0ef626	213	{
	214	Authctxt *authctxt = ctxt;
	215	Authmethod *m = NULL;
	216	char user, service, method, style = NULL;
	217	int authenticated = 0;
	218
	219	if (authctxt == NULL)
	220	fatal("input_userauth_request: no authctxt");
	221
	222	user = packet_get_string(NULL);
	223	service = packet_get_string(NULL);
	224	method = packet_get_string(NULL);
	225	debug("userauth-request for user %s service %s method %s", user, service, method);
c015d727	226	if (!log_flag) {
	227	logit("SSH: Server;Ltype: Authname;Remote: %s-%d;Name: %s",
	228	get_remote_ipaddr(), get_remote_port(), user);
	229	log_flag = 1;
	230	}
3c0ef626	231	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
	232
	233	if ((style = strchr(user, ':')) != NULL)
	234	*style++ = 0;
	235
	236	if (authctxt->attempt++ == 0) {
	237	/* setup auth context */
700318f3	238	authctxt->pw = PRIVSEP(getpwnamallow(user));
99be0775	239	authctxt->user = xstrdup(user);
700318f3	240	if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
3c0ef626	241	authctxt->valid = 1;
3c0ef626	242	debug2("input_userauth_request: setting up authctxt for %s", user);
3c0ef626	243	} else {
c9f39d2c	244	logit("input_userauth_request: invalid user %s", user);
0fff78ff	245	authctxt->pw = fakepw();
996d5e62	246	#ifdef SSH_AUDIT_EVENTS
996d5e62	247	PRIVSEP(audit_event(SSH_INVALID_USER));
3c0ef626	248	#endif
3c0ef626	249	}
2c06c99b	250	#ifdef USE_PAM
	251	if (options.use_pam)
	252	PRIVSEP(start_pam(authctxt));
	253	#endif
c9f39d2c	254	setproctitle("%s%s", authctxt->valid ? user : "unknown",
700318f3	255	use_privsep ? " [net]" : "");
3c0ef626	256	authctxt->service = xstrdup(service);
3c0ef626	257	authctxt->style = style ? xstrdup(style) : NULL;
700318f3	258	if (use_privsep)
700318f3	259	mm_inform_authserv(service, style);
22616013	260	userauth_banner();
3c0ef626	261	} else if (strcmp(user, authctxt->user) != 0 \|\|
	262	strcmp(service, authctxt->service) != 0) {
	263	packet_disconnect("Change of username or service not allowed: "
	264	"(%s,%s) -> (%s,%s)",
	265	authctxt->user, authctxt->service, user, service);
	266	}
	267	/* reset state */
e9a17296	268	auth2_challenge_stop(authctxt);
0fff78ff	269
	270	#ifdef GSSAPI
	271	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	272	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	273	#endif
	274
3c0ef626	275	authctxt->postponed = 0;
3c0ef626	276
	277	/* try to authenticate user */
	278	m = authmethod_lookup(method);
22616013	279	if (m != NULL && authctxt->failures < options.max_authtries) {
3c0ef626	280	debug2("input_userauth_request: try method %s", method);
	281	authenticated = m->userauth(authctxt);
	282	}
	283	userauth_finish(authctxt, authenticated, method);
	284
	285	xfree(service);
	286	xfree(user);
	287	xfree(method);
	288	}
	289
	290	void
	291	userauth_finish(Authctxt authctxt, int authenticated, char method)
	292	{
	293	char *methods;
	294
	295	if (!authctxt->valid && authenticated)
	296	fatal("INTERNAL ERROR: authenticated invalid user %s",
	297	authctxt->user);
	298
	299	/* Special handling for root */
6a9b3198	300	if (authenticated && authctxt->pw->pw_uid == 0 &&
996d5e62	301	!auth_root_allowed(method)) {
3c0ef626	302	authenticated = 0;
996d5e62	303	#ifdef SSH_AUDIT_EVENTS
	304	PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
	305	#endif
	306	}
3c0ef626	307
3c0ef626	308	#ifdef USE_PAM
996d5e62	309	if (options.use_pam && authenticated) {
	310	if (!PRIVSEP(do_pam_account())) {
	311	/* if PAM returned a message, send it to the user */
	312	if (buffer_len(&loginmsg) > 0) {
	313	buffer_append(&loginmsg, "\0", 1);
	314	userauth_send_banner(buffer_ptr(&loginmsg));
	315	packet_write_wait();
	316	}
	317	fatal("Access denied for user %s by PAM account "
665a873d	318	"configuration", authctxt->user);
996d5e62	319	}
996d5e62	320	}
0fff78ff	321	#endif
3c0ef626	322
41b2f314	323	#ifdef _UNICOS
	324	if (authenticated && cray_access_denied(authctxt->user)) {
	325	authenticated = 0;
	326	fatal("Access denied for user %s.",authctxt->user);
	327	}
	328	#endif /* _UNICOS */
	329
3c0ef626	330	/* Log before sending the reply */
	331	auth_log(authctxt, authenticated, method, " ssh2");
	332
	333	if (authctxt->postponed)
	334	return;
	335
	336	/* XXX todo: check if multiple auth methods are needed */
	337	if (authenticated == 1) {
	338	/* turn off userauth */
e9a17296	339	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
3c0ef626	340	packet_start(SSH2_MSG_USERAUTH_SUCCESS);
	341	packet_send();
	342	packet_write_wait();
	343	/* now we can break out */
	344	authctxt->success = 1;
	345	} else {
22616013	346
	347	/* Allow initial try of "none" auth without failure penalty */
	348	if (authctxt->attempt > 1 \|\| strcmp(method, "none") != 0)
	349	authctxt->failures++;
	350	if (authctxt->failures >= options.max_authtries) {
996d5e62	351	#ifdef SSH_AUDIT_EVENTS
	352	PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
	353	#endif
3c0ef626	354	packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
996d5e62	355	}
3c0ef626	356	methods = authmethods_get();
	357	packet_start(SSH2_MSG_USERAUTH_FAILURE);
	358	packet_put_cstring(methods);
	359	packet_put_char(0); /* XXX partial success, unused */
	360	packet_send();
	361	packet_write_wait();
	362	xfree(methods);
	363	}
	364	}
	365
3c0ef626	366	static char *
	367	authmethods_get(void)
	368	{
e9a17296	369	Buffer b;
3c0ef626	370	char *list;
f5799ae1	371	int i;
3c0ef626	372
e9a17296	373	buffer_init(&b);
f5799ae1	374	for (i = 0; authmethods[i] != NULL; i++) {
f5799ae1	375	if (strcmp(authmethods[i]->name, "none") == 0)
3c0ef626	376	continue;
f5799ae1	377	if (authmethods[i]->enabled != NULL &&
f5799ae1	378	*(authmethods[i]->enabled) != 0) {
e9a17296	379	if (buffer_len(&b) > 0)
e9a17296	380	buffer_append(&b, ",", 1);
f5799ae1	381	buffer_append(&b, authmethods[i]->name,
f5799ae1	382	strlen(authmethods[i]->name));
3c0ef626	383	}
3c0ef626	384	}
e9a17296	385	buffer_append(&b, "\0", 1);
	386	list = xstrdup(buffer_ptr(&b));
	387	buffer_free(&b);
3c0ef626	388	return list;
	389	}
	390
	391	static Authmethod *
	392	authmethod_lookup(const char *name)
	393	{
f5799ae1	394	int i;
f5799ae1	395
3c0ef626	396	if (name != NULL)
f5799ae1	397	for (i = 0; authmethods[i] != NULL; i++)
	398	if (authmethods[i]->enabled != NULL &&
	399	*(authmethods[i]->enabled) != 0 &&
	400	strcmp(name, authmethods[i]->name) == 0)
	401	return authmethods[i];
	402	debug2("Unrecognized authentication method name: %s",
	403	name ? name : "NULL");
3c0ef626	404	return NULL;
3c0ef626	405	}
22616013	406