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

/*	$OpenBSD: auth2-gss.c,v 1.8 2004/06/21 17:36:31 avsm Exp $	*/

/*
 * Copyright (c) 2001-2003 Simon Wilkinson. 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"

#ifdef GSSAPI

#include "auth.h"
#include "ssh2.h"
#include "xmalloc.h"
#include "log.h"
#include "dispatch.h"
#include "servconf.h"
#include "compat.h"
#include "packet.h"
#include "monitor_wrap.h"

#include "ssh-gss.h"

extern ServerOptions options;

static void ssh_gssapi_userauth_error(Gssctxt *ctxt);
static void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
static void input_gssapi_errtok(int, u_int32_t, void *);

static int gssapi_with_mic = 1;	/* flag to toggle "gssapi-with-mic" vs.
				   "gssapi" */

static int
userauth_external(Authctxt *authctxt)
{
        packet_check_eom();

	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
		return(PRIVSEP(ssh_gssapi_userok(authctxt->user)));
	}
	return 0;
}

/*
 * We only support those mechanisms that we know about (ie ones that we know
 * how to check local user kuserok and the like
 */
static int
userauth_gssapi(Authctxt *authctxt)
{
	gss_OID_desc goid = {0, NULL};
	Gssctxt *ctxt = NULL;
	int mechs;
	gss_OID_set supported;
	int present;
	OM_uint32 ms;
	u_int len;
	char *doid = NULL;

	if (authctxt->user == NULL)
		return (0);

	mechs = packet_get_int();
	if (mechs == 0) {
		debug("Mechanism negotiation is not supported");
		return (0);
	}

	ssh_gssapi_supported_oids(&supported);
	do {
		mechs--;

		if (doid)
			xfree(doid);

		present = 0;
		doid = packet_get_string(&len);

		if (doid[0] != SSH_GSS_OIDTYPE || doid[1] != len-2) {
			logit("Mechanism OID received using the old encoding form");
			goid.elements = doid;
			goid.length = len;
		} else {
			goid.elements = doid + 2;
			goid.length   = len - 2;
		}
		gss_test_oid_set_member(&ms, &goid, supported, &present);
	} while (mechs > 0 && !present);

	gss_release_oid_set(&ms, &supported);

	if (!present) {
		xfree(doid);
		return (0);
	}

	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
		xfree(doid);
		return (0);
	}

	authctxt->methoddata=(void *)ctxt;

	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);

	/* Return the OID that we received */
	packet_put_string(doid, len);

	packet_send();
	xfree(doid);

	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
	authctxt->postponed = 1;

	return (0);
}

static void
input_gssapi_token(int type, u_int32_t plen, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Gssctxt *gssctxt;
	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	gss_buffer_desc recv_tok;
	OM_uint32 maj_status, min_status, flags=0;
	u_int len;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssctxt = authctxt->methoddata;
	recv_tok.value = packet_get_string(&len);
	recv_tok.length = len; /* u_int vs. size_t */

	packet_check_eom();

	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	    &send_tok, &flags));

	xfree(recv_tok.value);

	if (GSS_ERROR(maj_status)) {
        	ssh_gssapi_userauth_error(gssctxt);
		if (send_tok.length != 0) {
			packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
			packet_put_string(send_tok.value, send_tok.length);
			packet_send();
		}
		authctxt->postponed = 0;
		dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
		userauth_finish(authctxt, 0,
				gssapi_with_mic ? "gssapi-with-mic" :
				                  "gssapi");
	} else {
		if (send_tok.length != 0) {
			packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
			packet_put_string(send_tok.value, send_tok.length);
			packet_send();
		}
		if (maj_status == GSS_S_COMPLETE) {
			dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
			if (flags & GSS_C_INTEG_FLAG && gssapi_with_mic)
				dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
				    &input_gssapi_mic);
			else
				dispatch_set(
				    SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
				    &input_gssapi_exchange_complete);
		}
	}

	gss_release_buffer(&min_status, &send_tok);
}

static void
input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Gssctxt *gssctxt;
	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	gss_buffer_desc recv_tok;
	OM_uint32 maj_status;
	u_int len;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssctxt = authctxt->methoddata;
	recv_tok.value = packet_get_string(&len);
	recv_tok.length = len;

	packet_check_eom();

	/* Push the error token into GSSAPI to see what it says */
	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	    &send_tok, NULL));

	xfree(recv_tok.value);

	/* We can't return anything to the client, even if we wanted to */
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);

	/* The client will have already moved on to the next auth */

	gss_release_buffer(&maj_status, &send_tok);
}

static void
gssapi_set_implicit_username(Authctxt *authctxt)
{
    if ((authctxt->user == NULL) || (strcmp(authctxt->user, "") == 0)) {
	char *lname = NULL;
	PRIVSEP(ssh_gssapi_localname(&lname));
	if (lname && lname[0] != '\0') {
	    xfree(authctxt->user);
	    authctxt->user = lname;
	    debug("set username to %s from gssapi context", lname);
	    authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
	    if (authctxt->pw) {
		authctxt->valid = 1;
	    }
	} else {
	    debug("failed to set username from gssapi context");
	}
    }
    if (authctxt->pw) {
#ifdef USE_PAM
	if (options.use_pam)
		PRIVSEP(start_pam(authctxt));
#endif
    }
}

/*
 * This is called when the client thinks we've completed authentication.
 * It should only be enabled in the dispatch handler by the function above,
 * which only enables it once the GSSAPI exchange is complete.
 */

static void
input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Gssctxt *gssctxt;
	int authenticated;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssapi_set_implicit_username(authctxt);

	gssctxt = authctxt->methoddata;

	/*
	 * We don't need to check the status, because we're only enabled in
	 * the dispatcher once the exchange is complete
	 */

	packet_check_eom();

	if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
	    authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	} else {
	    authenticated = 0;
	}

	authctxt->postponed = 0;
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	userauth_finish(authctxt, authenticated,
			gssapi_with_mic ? "gssapi-with-mic" : "gssapi");
}

static int
userauth_gssapi_with_mic(Authctxt *authctxt)
{
    gssapi_with_mic = 1;
    return userauth_gssapi(authctxt);
}

static int
userauth_gssapi_without_mic(Authctxt *authctxt)
{
    gssapi_with_mic = 0;
    return userauth_gssapi(authctxt);
}

static void
input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
{
	Authctxt *authctxt = ctxt;
	Gssctxt *gssctxt;
	int authenticated = 0;
	Buffer b;
	gss_buffer_desc mic, gssbuf;
	u_int len;

	if (authctxt == NULL || (authctxt->methoddata == NULL && !use_privsep))
		fatal("No authentication or GSSAPI context");

	gssapi_set_implicit_username(authctxt);

	gssctxt = authctxt->methoddata;

	mic.value = packet_get_string(&len);
	mic.length = len;

	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	    "gssapi-with-mic");

	gssbuf.value = buffer_ptr(&b);
	gssbuf.length = buffer_len(&b);

	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
	    if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
		authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	    } else {
		authenticated = 0;
	    }
	else
		logit("GSSAPI MIC check failed");

	buffer_free(&b);
	xfree(mic.value);

	authctxt->postponed = 0;
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
}

static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
	char *errstr;
	OM_uint32 maj,min;
	
	errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
	if (errstr) {
		packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
		packet_put_int(maj);
		packet_put_int(min);
		packet_put_cstring(errstr);
		packet_put_cstring("");
		packet_send();
		packet_write_wait();
		xfree(errstr);
	}
}

Authmethod method_external = {
	"external-keyx",
	userauth_external,
	&options.gss_authentication
};
	
Authmethod method_gssapi = {
	"gssapi-with-mic",
	userauth_gssapi_with_mic,
	&options.gss_authentication
};

Authmethod method_gssapi_compat = {
	"gssapi",
	userauth_gssapi_without_mic,
	&options.gss_authentication
};

#endif /* GSSAPI */
Commit	Line	Data
7e82606e	1	/* $OpenBSD: auth2-gss.c,v 1.8 2004/06/21 17:36:31 avsm Exp $ */
7cac2b65	2
b59afbfe	3	/*
23987cb8	4	* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
b59afbfe	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions
	8	* are met:
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	*
	15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AS IS'' AND ANY EXPRESS OR
	16	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	17	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	18	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	19	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	20	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	21	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	22	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	23	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	24	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	25	*/
	26
	27	#include "includes.h"
	28
	29	#ifdef GSSAPI
7cac2b65	30
b59afbfe	31	#include "auth.h"
b59afbfe	32	#include "ssh2.h"
b59afbfe	33	#include "xmalloc.h"
	34	#include "log.h"
	35	#include "dispatch.h"
	36	#include "servconf.h"
	37	#include "compat.h"
	38	#include "packet.h"
	39	#include "monitor_wrap.h"
	40
	41	#include "ssh-gss.h"
	42
	43	extern ServerOptions options;
b59afbfe	44
23987cb8	45	static void ssh_gssapi_userauth_error(Gssctxt *ctxt);
b59afbfe	46	static void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
540d72c3	47	static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
b59afbfe	48	static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
e23e524c	49	static void input_gssapi_errtok(int, u_int32_t, void *);
b59afbfe	50
540d72c3	51	static int gssapi_with_mic = 1; /* flag to toggle "gssapi-with-mic" vs.
	52	"gssapi" */
	53
5217e987	54	static int
	55	userauth_external(Authctxt *authctxt)
	56	{
	57	packet_check_eom();
	58
7a8e5702	59	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
294206af	60	return(PRIVSEP(ssh_gssapi_userok(authctxt->user)));
5217e987	61	}
	62	return 0;
	63	}
	64
7cac2b65	65	/*
7cac2b65	66	* We only support those mechanisms that we know about (ie ones that we know
b59afbfe	67	* how to check local user kuserok and the like
	68	*/
	69	static int
	70	userauth_gssapi(Authctxt *authctxt)
	71	{
7e82606e	72	gss_OID_desc goid = {0, NULL};
7cac2b65	73	Gssctxt *ctxt = NULL;
	74	int mechs;
	75	gss_OID_set supported;
	76	int present;
	77	OM_uint32 ms;
	78	u_int len;
	79	char *doid = NULL;
	80
5217e987	81	if (authctxt->user == NULL)
7cac2b65	82	return (0);
	83
	84	mechs = packet_get_int();
	85	if (mechs == 0) {
	86	debug("Mechanism negotiation is not supported");
	87	return (0);
	88	}
	89
	90	ssh_gssapi_supported_oids(&supported);
	91	do {
	92	mechs--;
	93
	94	if (doid)
	95	xfree(doid);
	96
540d72c3	97	present = 0;
7cac2b65	98	doid = packet_get_string(&len);
	99
	100	if (doid[0] != SSH_GSS_OIDTYPE \|\| doid[1] != len-2) {
	101	logit("Mechanism OID received using the old encoding form");
7e82606e	102	goid.elements = doid;
7e82606e	103	goid.length = len;
7cac2b65	104	} else {
7e82606e	105	goid.elements = doid + 2;
7e82606e	106	goid.length = len - 2;
7cac2b65	107	}
7e82606e	108	gss_test_oid_set_member(&ms, &goid, supported, &present);
7cac2b65	109	} while (mechs > 0 && !present);
	110
	111	gss_release_oid_set(&ms, &supported);
	112
	113	if (!present) {
	114	xfree(doid);
	115	return (0);
	116	}
	117
7e82606e	118	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
7cac2b65	119	xfree(doid);
7cac2b65	120	return (0);
23987cb8	121	}
b59afbfe	122
7cac2b65	123	authctxt->methoddata=(void *)ctxt;
b59afbfe	124
7cac2b65	125	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
23987cb8	126
540d72c3	127	/* Return the OID that we received */
7cac2b65	128	packet_put_string(doid, len);
23987cb8	129
7cac2b65	130	packet_send();
7cac2b65	131	xfree(doid);
b59afbfe	132
7cac2b65	133	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
	134	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
	135	authctxt->postponed = 1;
	136
	137	return (0);
b59afbfe	138	}
	139
	140	static void
	141	input_gssapi_token(int type, u_int32_t plen, void *ctxt)
	142	{
7cac2b65	143	Authctxt *authctxt = ctxt;
	144	Gssctxt *gssctxt;
	145	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	146	gss_buffer_desc recv_tok;
147c00cc	147	OM_uint32 maj_status, min_status, flags=0;
7cac2b65	148	u_int len;
	149
	150	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	151	fatal("No authentication or GSSAPI context");
	152
	153	gssctxt = authctxt->methoddata;
	154	recv_tok.value = packet_get_string(&len);
	155	recv_tok.length = len; /* u_int vs. size_t */
	156
	157	packet_check_eom();
	158
	159	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
540d72c3	160	&send_tok, &flags));
7cac2b65	161
	162	xfree(recv_tok.value);
	163
	164	if (GSS_ERROR(maj_status)) {
e23e524c	165	ssh_gssapi_userauth_error(gssctxt);
e23e524c	166	if (send_tok.length != 0) {
e23e524c	167	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
7cac2b65	168	packet_put_string(send_tok.value, send_tok.length);
	169	packet_send();
	170	}
	171	authctxt->postponed = 0;
7cac2b65	172	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
540d72c3	173	userauth_finish(authctxt, 0,
	174	gssapi_with_mic ? "gssapi-with-mic" :
	175	"gssapi");
7cac2b65	176	} else {
7cac2b65	177	if (send_tok.length != 0) {
7cac2b65	178	packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
	179	packet_put_string(send_tok.value, send_tok.length);
	180	packet_send();
	181	}
	182	if (maj_status == GSS_S_COMPLETE) {
7cac2b65	183	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
540d72c3	184	if (flags & GSS_C_INTEG_FLAG && gssapi_with_mic)
	185	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
	186	&input_gssapi_mic);
	187	else
	188	dispatch_set(
	189	SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
	190	&input_gssapi_exchange_complete);
7cac2b65	191	}
	192	}
	193
	194	gss_release_buffer(&min_status, &send_tok);
e23e524c	195	}
23987cb8	196
e23e524c	197	static void
	198	input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
	199	{
7cac2b65	200	Authctxt *authctxt = ctxt;
	201	Gssctxt *gssctxt;
	202	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	203	gss_buffer_desc recv_tok;
	204	OM_uint32 maj_status;
	205	u_int len;
	206
	207	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	208	fatal("No authentication or GSSAPI context");
	209
	210	gssctxt = authctxt->methoddata;
	211	recv_tok.value = packet_get_string(&len);
	212	recv_tok.length = len;
	213
	214	packet_check_eom();
	215
	216	/* Push the error token into GSSAPI to see what it says */
	217	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	218	&send_tok, NULL));
	219
	220	xfree(recv_tok.value);
e23e524c	221
e23e524c	222	/* We can't return anything to the client, even if we wanted to */
e23e524c	223	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
7cac2b65	224	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
e23e524c	225
e23e524c	226	/* The client will have already moved on to the next auth */
7cac2b65	227
7cac2b65	228	gss_release_buffer(&maj_status, &send_tok);
b59afbfe	229	}
b59afbfe	230
540d72c3	231	static void
	232	gssapi_set_implicit_username(Authctxt *authctxt)
	233	{
294206af	234	if ((authctxt->user == NULL) \|\| (strcmp(authctxt->user, "") == 0)) {
540d72c3	235	char *lname = NULL;
	236	PRIVSEP(ssh_gssapi_localname(&lname));
	237	if (lname && lname[0] != '\0') {
	238	xfree(authctxt->user);
	239	authctxt->user = lname;
	240	debug("set username to %s from gssapi context", lname);
	241	authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
5217e987	242	if (authctxt->pw) {
	243	authctxt->valid = 1;
	244	}
540d72c3	245	} else {
	246	debug("failed to set username from gssapi context");
	247	}
	248	}
	249	if (authctxt->pw) {
	250	#ifdef USE_PAM
147c00cc	251	if (options.use_pam)
5217e987	252	PRIVSEP(start_pam(authctxt));
540d72c3	253	#endif
	254	}
	255	}
	256
7cac2b65	257	/*
7cac2b65	258	* This is called when the client thinks we've completed authentication.
b59afbfe	259	* It should only be enabled in the dispatch handler by the function above,
	260	* which only enables it once the GSSAPI exchange is complete.
	261	*/
7cac2b65	262
b59afbfe	263	static void
	264	input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
	265	{
7cac2b65	266	Authctxt *authctxt = ctxt;
	267	Gssctxt *gssctxt;
	268	int authenticated;
	269
b59afbfe	270	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
7cac2b65	271	fatal("No authentication or GSSAPI context");
7cac2b65	272
540d72c3	273	gssapi_set_implicit_username(authctxt);
d13dfff4	274
7cac2b65	275	gssctxt = authctxt->methoddata;
7cac2b65	276
7cac2b65	277	/*
540d72c3	278	* We don't need to check the status, because we're only enabled in
540d72c3	279	* the dispatcher once the exchange is complete
b59afbfe	280	*/
b59afbfe	281
7cac2b65	282	packet_check_eom();
7cac2b65	283
5217e987	284	if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
540d72c3	285	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	286	} else {
	287	authenticated = 0;
	288	}
b59afbfe	289
7cac2b65	290	authctxt->postponed = 0;
	291	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	292	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
540d72c3	293	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
7cac2b65	294	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
540d72c3	295	userauth_finish(authctxt, authenticated,
	296	gssapi_with_mic ? "gssapi-with-mic" : "gssapi");
	297	}
	298
	299	static int
	300	userauth_gssapi_with_mic(Authctxt *authctxt)
	301	{
	302	gssapi_with_mic = 1;
	303	return userauth_gssapi(authctxt);
	304	}
	305
	306	static int
	307	userauth_gssapi_without_mic(Authctxt *authctxt)
	308	{
	309	gssapi_with_mic = 0;
	310	return userauth_gssapi(authctxt);
	311	}
	312
	313	static void
	314	input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
	315	{
	316	Authctxt *authctxt = ctxt;
	317	Gssctxt *gssctxt;
	318	int authenticated = 0;
	319	Buffer b;
	320	gss_buffer_desc mic, gssbuf;
	321	u_int len;
	322
	323	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	324	fatal("No authentication or GSSAPI context");
	325
	326	gssapi_set_implicit_username(authctxt);
	327
	328	gssctxt = authctxt->methoddata;
	329
	330	mic.value = packet_get_string(&len);
	331	mic.length = len;
	332
	333	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	334	"gssapi-with-mic");
	335
	336	gssbuf.value = buffer_ptr(&b);
	337	gssbuf.length = buffer_len(&b);
	338
	339	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
5217e987	340	if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
540d72c3	341	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	342	} else {
	343	authenticated = 0;
	344	}
	345	else
	346	logit("GSSAPI MIC check failed");
	347
	348	buffer_free(&b);
	349	xfree(mic.value);
	350
	351	authctxt->postponed = 0;
	352	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	353	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	354	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	355	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	356	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
b59afbfe	357	}
b59afbfe	358
23987cb8	359	static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
	360	char *errstr;
	361	OM_uint32 maj,min;
	362
	363	errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
	364	if (errstr) {
	365	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
	366	packet_put_int(maj);
	367	packet_put_int(min);
	368	packet_put_cstring(errstr);
	369	packet_put_cstring("");
	370	packet_send();
	371	packet_write_wait();
	372	xfree(errstr);
	373	}
	374	}
	375
b59afbfe	376	Authmethod method_external = {
	377	"external-keyx",
	378	userauth_external,
	379	&options.gss_authentication
	380	};
	381
	382	Authmethod method_gssapi = {
540d72c3	383	"gssapi-with-mic",
	384	userauth_gssapi_with_mic,
	385	&options.gss_authentication
	386	};
	387
	388	Authmethod method_gssapi_compat = {
7cac2b65	389	"gssapi",
540d72c3	390	userauth_gssapi_without_mic,
7cac2b65	391	&options.gss_authentication
b59afbfe	392	};
	393
	394	#endif /* GSSAPI */