[openssh.git] / 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"

#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

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);
	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
71709bcd	1	/* $OpenBSD: auth2.c,v 1.119 2008/07/04 23:30:16 djm Exp $ */
a306f2dd	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.
a306f2dd	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	*/
bcbf86ec	25
a306f2dd	26	#include "includes.h"
a306f2dd	27
b1842393	28	#include <sys/types.h>
221fc73c	29	#include <sys/stat.h>
221fc73c	30	#include <sys/uio.h>
b1842393	31
221fc73c	32	#include <fcntl.h>
b1842393	33	#include <pwd.h>
31652869	34	#include <stdarg.h>
00146caa	35	#include <string.h>
221fc73c	36	#include <unistd.h>
b1842393	37
a306f2dd	38	#include "xmalloc.h"
71709bcd	39	#include "atomicio.h"
31652869	40	#include "ssh2.h"
a306f2dd	41	#include "packet.h"
42f11eb2	42	#include "log.h"
31652869	43	#include "buffer.h"
a306f2dd	44	#include "servconf.h"
a306f2dd	45	#include "compat.h"
31652869	46	#include "key.h"
31652869	47	#include "hostfile.h"
a306f2dd	48	#include "auth.h"
a306f2dd	49	#include "dispatch.h"
42f11eb2	50	#include "pathnames.h"
ba6dd90e	51	#include "buffer.h"
a306f2dd	52
7364bd04	53	#ifdef GSSAPI
	54	#include "ssh-gss.h"
	55	#endif
31652869	56	#include "monitor_wrap.h"
7364bd04	57
a306f2dd	58	/* import */
a306f2dd	59	extern ServerOptions options;
1e3b8b07	60	extern u_char *session_id2;
a27002e5	61	extern u_int session_id2_len;
ba6dd90e	62	extern Buffer loginmsg;
a306f2dd	63
01c24737	64	/* methods */
	65
	66	extern Authmethod method_none;
	67	extern Authmethod method_pubkey;
	68	extern Authmethod method_passwd;
	69	extern Authmethod method_kbdint;
	70	extern Authmethod method_hostbased;
7364bd04	71	#ifdef GSSAPI
	72	extern Authmethod method_gssapi;
	73	#endif
01c24737	74
	75	Authmethod *authmethods[] = {
	76	&method_none,
	77	&method_pubkey,
7364bd04	78	#ifdef GSSAPI
	79	&method_gssapi,
	80	#endif
01c24737	81	&method_passwd,
	82	&method_kbdint,
	83	&method_hostbased,
	84	NULL
94ec8c6b	85	};
94ec8c6b	86
a306f2dd	87	/* protocol */
a306f2dd	88
7819b5c3	89	static void input_service_request(int, u_int32_t, void *);
7819b5c3	90	static void input_userauth_request(int, u_int32_t, void *);
a306f2dd	91
a306f2dd	92	/* helper */
396c147e	93	static Authmethod authmethod_lookup(const char );
ffb215be	94	static char *authmethods_get(void);
a306f2dd	95
221fc73c	96	char *
	97	auth2_read_banner(void)
	98	{
	99	struct stat st;
	100	char *banner = NULL;
	101	size_t len, n;
	102	int fd;
	103
	104	if ((fd = open(options.banner, O_RDONLY)) == -1)
	105	return (NULL);
	106	if (fstat(fd, &st) == -1) {
	107	close(fd);
	108	return (NULL);
	109	}
	110	if (st.st_size > 110241024) {
	111	close(fd);
	112	return (NULL);
	113	}
	114
	115	len = (size_t)st.st_size; /* truncate */
	116	banner = xmalloc(len + 1);
	117	n = atomicio(read, fd, banner, len);
	118	close(fd);
	119
	120	if (n != len) {
	121	xfree(banner);
	122	return (NULL);
	123	}
	124	banner[n] = '\0';
	125
	126	return (banner);
	127	}
	128
	129	void
	130	userauth_send_banner(const char *msg)
	131	{
	132	if (datafellows & SSH_BUG_BANNER)
	133	return;
	134
	135	packet_start(SSH2_MSG_USERAUTH_BANNER);
	136	packet_put_cstring(msg);
	137	packet_put_cstring(""); /* language, unused */
	138	packet_send();
	139	debug("%s: sent", __func__);
	140	}
	141
	142	static void
	143	userauth_banner(void)
	144	{
	145	char *banner = NULL;
	146
	147	if (options.banner == NULL \|\|
	148	strcasecmp(options.banner, "none") == 0 \|\|
	149	(datafellows & SSH_BUG_BANNER) != 0)
	150	return;
	151
	152	if ((banner = PRIVSEP(auth2_read_banner())) == NULL)
	153	goto done;
	154	userauth_send_banner(banner);
	155
	156	done:
	157	if (banner)
	158	xfree(banner);
	159	}
160
a306f2dd	161	/*
94ec8c6b	162	* loop until authctxt->success == TRUE
a306f2dd	163	*/
2362db19	164	void
2362db19	165	do_authentication2(Authctxt *authctxt)
a306f2dd	166	{
6367063f	167	dispatch_init(&dispatch_protocol_error);
a306f2dd	168	dispatch_set(SSH2_MSG_SERVICE_REQUEST, &input_service_request);
94ec8c6b	169	dispatch_run(DISPATCH_BLOCK, &authctxt->success, authctxt);
a306f2dd	170	}
a306f2dd	171
fe8c3af1	172	/ARGSUSED/
396c147e	173	static void
7819b5c3	174	input_service_request(int type, u_int32_t seq, void *ctxt)
a306f2dd	175	{
94ec8c6b	176	Authctxt *authctxt = ctxt;
1e3b8b07	177	u_int len;
7fdc56c5	178	int acceptit = 0;
a306f2dd	179	char *service = packet_get_string(&len);
95500969	180	packet_check_eom();
a306f2dd	181
94ec8c6b	182	if (authctxt == NULL)
	183	fatal("input_service_request: no authctxt");
	184
a306f2dd	185	if (strcmp(service, "ssh-userauth") == 0) {
94ec8c6b	186	if (!authctxt->success) {
7fdc56c5	187	acceptit = 1;
a306f2dd	188	/* now we can handle user-auth requests */
	189	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &input_userauth_request);
	190	}
	191	}
	192	/* XXX all other service requests are denied */
	193
7fdc56c5	194	if (acceptit) {
a306f2dd	195	packet_start(SSH2_MSG_SERVICE_ACCEPT);
	196	packet_put_cstring(service);
	197	packet_send();
	198	packet_write_wait();
	199	} else {
	200	debug("bad service request %s", service);
	201	packet_disconnect("bad service request %s", service);
	202	}
	203	xfree(service);
	204	}
	205
fe8c3af1	206	/ARGSUSED/
396c147e	207	static void
7819b5c3	208	input_userauth_request(int type, u_int32_t seq, void *ctxt)
a306f2dd	209	{
94ec8c6b	210	Authctxt *authctxt = ctxt;
94ec8c6b	211	Authmethod *m = NULL;
59c97189	212	char user, service, method, style = NULL;
a306f2dd	213	int authenticated = 0;
a306f2dd	214
94ec8c6b	215	if (authctxt == NULL)
94ec8c6b	216	fatal("input_userauth_request: no authctxt");
a306f2dd	217
94ec8c6b	218	user = packet_get_string(NULL);
	219	service = packet_get_string(NULL);
	220	method = packet_get_string(NULL);
	221	debug("userauth-request for user %s service %s method %s", user, service, method);
8abcdba4	222	debug("attempt %d failures %d", authctxt->attempt, authctxt->failures);
94ec8c6b	223
59c97189	224	if ((style = strchr(user, ':')) != NULL)
	225	*style++ = 0;
	226
2b87da3b	227	if (authctxt->attempt++ == 0) {
63284fbb	228	/* setup auth context */
f7ed12f1	229	authctxt->pw = PRIVSEP(getpwnamallow(user));
529d73ab	230	authctxt->user = xstrdup(user);
f7ed12f1	231	if (authctxt->pw && strcmp(service, "ssh-connection")==0) {
94ec8c6b	232	authctxt->valid = 1;
94ec8c6b	233	debug2("input_userauth_request: setting up authctxt for %s", user);
94ec8c6b	234	} else {
d77347cc	235	logit("input_userauth_request: invalid user %s", user);
96d0bf74	236	authctxt->pw = fakepw();
6039eeef	237	#ifdef SSH_AUDIT_EVENTS
6039eeef	238	PRIVSEP(audit_event(SSH_INVALID_USER));
04fc7a67	239	#endif
94ec8c6b	240	}
b6c37221	241	#ifdef USE_PAM
	242	if (options.use_pam)
	243	PRIVSEP(start_pam(authctxt));
	244	#endif
bd5c0694	245	setproctitle("%s%s", authctxt->valid ? user : "unknown",
1853d1ef	246	use_privsep ? " [net]" : "");
94ec8c6b	247	authctxt->service = xstrdup(service);
2a6a054e	248	authctxt->style = style ? xstrdup(style) : NULL;
1853d1ef	249	if (use_privsep)
1853d1ef	250	mm_inform_authserv(service, style);
221fc73c	251	userauth_banner();
2a6a054e	252	} else if (strcmp(user, authctxt->user) != 0 \|\|
	253	strcmp(service, authctxt->service) != 0) {
	254	packet_disconnect("Change of username or service not allowed: "
	255	"(%s,%s) -> (%s,%s)",
	256	authctxt->user, authctxt->service, user, service);
a306f2dd	257	}
59c97189	258	/* reset state */
2f293d43	259	auth2_challenge_stop(authctxt);
7364bd04	260
	261	#ifdef GSSAPI
	262	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	263	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	264	#endif
	265
59c97189	266	authctxt->postponed = 0;
9cd45ea4	267
59c97189	268	/* try to authenticate user */
94ec8c6b	269	m = authmethod_lookup(method);
221fc73c	270	if (m != NULL && authctxt->failures < options.max_authtries) {
94ec8c6b	271	debug2("input_userauth_request: try method %s", method);
94ec8c6b	272	authenticated = m->userauth(authctxt);
9cd45ea4	273	}
d9cd3575	274	userauth_finish(authctxt, authenticated, method);
	275
	276	xfree(service);
	277	xfree(user);
	278	xfree(method);
	279	}
	280
	281	void
	282	userauth_finish(Authctxt authctxt, int authenticated, char method)
	283	{
4e81159c	284	char *methods;
4e81159c	285
59c97189	286	if (!authctxt->valid && authenticated)
	287	fatal("INTERNAL ERROR: authenticated invalid user %s",
	288	authctxt->user);
9cd45ea4	289
94ec8c6b	290	/* Special handling for root */
5d47f1d4	291	if (authenticated && authctxt->pw->pw_uid == 0 &&
c00e4d75	292	!auth_root_allowed(method)) {
a306f2dd	293	authenticated = 0;
6039eeef	294	#ifdef SSH_AUDIT_EVENTS
6039eeef	295	PRIVSEP(audit_event(SSH_LOGIN_ROOT_DENIED));
c00e4d75	296	#endif
c00e4d75	297	}
a306f2dd	298
5b9e2464	299	#ifdef USE_PAM
ba6dd90e	300	if (options.use_pam && authenticated) {
ba6dd90e	301	if (!PRIVSEP(do_pam_account())) {
ba6dd90e	302	/* if PAM returned a message, send it to the user */
	303	if (buffer_len(&loginmsg) > 0) {
	304	buffer_append(&loginmsg, "\0", 1);
	305	userauth_send_banner(buffer_ptr(&loginmsg));
9aab0af7	306	packet_write_wait();
ba6dd90e	307	}
9aab0af7	308	fatal("Access denied for user %s by PAM account "
98c044d0	309	"configuration", authctxt->user);
ba6dd90e	310	}
ba6dd90e	311	}
5b9e2464	312	#endif
5b9e2464	313
ef51930f	314	#ifdef _UNICOS
	315	if (authenticated && cray_access_denied(authctxt->user)) {
	316	authenticated = 0;
	317	fatal("Access denied for user %s.",authctxt->user);
	318	}
	319	#endif /* _UNICOS */
	320
94ec8c6b	321	/* Log before sending the reply */
59c97189	322	auth_log(authctxt, authenticated, method, " ssh2");
59c97189	323
4e81159c	324	if (authctxt->postponed)
	325	return;
	326
	327	/* XXX todo: check if multiple auth methods are needed */
	328	if (authenticated == 1) {
	329	/* turn off userauth */
6367063f	330	dispatch_set(SSH2_MSG_USERAUTH_REQUEST, &dispatch_protocol_ignore);
4e81159c	331	packet_start(SSH2_MSG_USERAUTH_SUCCESS);
	332	packet_send();
	333	packet_write_wait();
	334	/* now we can break out */
	335	authctxt->success = 1;
	336	} else {
71709bcd	337
	338	/* Allow initial try of "none" auth without failure penalty */
	339	if (authctxt->attempt > 1 \|\| strcmp(method, "none") != 0)
	340	authctxt->failures++;
	341	if (authctxt->failures >= options.max_authtries) {
6039eeef	342	#ifdef SSH_AUDIT_EVENTS
6039eeef	343	PRIVSEP(audit_event(SSH_LOGIN_EXCEED_MAXTRIES));
c00e4d75	344	#endif
4e81159c	345	packet_disconnect(AUTH_FAIL_MSG, authctxt->user);
c00e4d75	346	}
4e81159c	347	methods = authmethods_get();
	348	packet_start(SSH2_MSG_USERAUTH_FAILURE);
	349	packet_put_cstring(methods);
	350	packet_put_char(0); /* XXX partial success, unused */
	351	packet_send();
	352	packet_write_wait();
	353	xfree(methods);
	354	}
94ec8c6b	355	}
94ec8c6b	356
ffb215be	357	static char *
94ec8c6b	358	authmethods_get(void)
a306f2dd	359	{
3469eac4	360	Buffer b;
94ec8c6b	361	char *list;
01c24737	362	int i;
94ec8c6b	363
3469eac4	364	buffer_init(&b);
01c24737	365	for (i = 0; authmethods[i] != NULL; i++) {
01c24737	366	if (strcmp(authmethods[i]->name, "none") == 0)
94ec8c6b	367	continue;
01c24737	368	if (authmethods[i]->enabled != NULL &&
01c24737	369	*(authmethods[i]->enabled) != 0) {
3469eac4	370	if (buffer_len(&b) > 0)
3469eac4	371	buffer_append(&b, ",", 1);
01c24737	372	buffer_append(&b, authmethods[i]->name,
01c24737	373	strlen(authmethods[i]->name));
a306f2dd	374	}
a306f2dd	375	}
3469eac4	376	buffer_append(&b, "\0", 1);
	377	list = xstrdup(buffer_ptr(&b));
	378	buffer_free(&b);
94ec8c6b	379	return list;
	380	}
	381
396c147e	382	static Authmethod *
94ec8c6b	383	authmethod_lookup(const char *name)
94ec8c6b	384	{
01c24737	385	int i;
01c24737	386
94ec8c6b	387	if (name != NULL)
01c24737	388	for (i = 0; authmethods[i] != NULL; i++)
	389	if (authmethods[i]->enabled != NULL &&
	390	*(authmethods[i]->enabled) != 0 &&
	391	strcmp(name, authmethods[i]->name) == 0)
	392	return authmethods[i];
	393	debug2("Unrecognized authentication method name: %s",
	394	name ? name : "NULL");
94ec8c6b	395	return NULL;
a306f2dd	396	}
221fc73c	397