[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 &&
	    strcmp(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
294206af	59	if (authctxt->valid && authctxt->user &&
	60	strcmp(authctxt->user, "") != 0) {
	61	return(PRIVSEP(ssh_gssapi_userok(authctxt->user)));
5217e987	62	}
	63	return 0;
	64	}
	65
7cac2b65	66	/*
7cac2b65	67	* We only support those mechanisms that we know about (ie ones that we know
b59afbfe	68	* how to check local user kuserok and the like
	69	*/
	70	static int
	71	userauth_gssapi(Authctxt *authctxt)
	72	{
7e82606e	73	gss_OID_desc goid = {0, NULL};
7cac2b65	74	Gssctxt *ctxt = NULL;
	75	int mechs;
	76	gss_OID_set supported;
	77	int present;
	78	OM_uint32 ms;
	79	u_int len;
	80	char *doid = NULL;
	81
5217e987	82	if (authctxt->user == NULL)
7cac2b65	83	return (0);
	84
	85	mechs = packet_get_int();
	86	if (mechs == 0) {
	87	debug("Mechanism negotiation is not supported");
	88	return (0);
	89	}
	90
	91	ssh_gssapi_supported_oids(&supported);
	92	do {
	93	mechs--;
	94
	95	if (doid)
	96	xfree(doid);
	97
540d72c3	98	present = 0;
7cac2b65	99	doid = packet_get_string(&len);
	100
	101	if (doid[0] != SSH_GSS_OIDTYPE \|\| doid[1] != len-2) {
	102	logit("Mechanism OID received using the old encoding form");
7e82606e	103	goid.elements = doid;
7e82606e	104	goid.length = len;
7cac2b65	105	} else {
7e82606e	106	goid.elements = doid + 2;
7e82606e	107	goid.length = len - 2;
7cac2b65	108	}
7e82606e	109	gss_test_oid_set_member(&ms, &goid, supported, &present);
7cac2b65	110	} while (mechs > 0 && !present);
	111
	112	gss_release_oid_set(&ms, &supported);
	113
	114	if (!present) {
	115	xfree(doid);
	116	return (0);
	117	}
	118
7e82606e	119	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
7cac2b65	120	xfree(doid);
7cac2b65	121	return (0);
23987cb8	122	}
b59afbfe	123
7cac2b65	124	authctxt->methoddata=(void *)ctxt;
b59afbfe	125
7cac2b65	126	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
23987cb8	127
540d72c3	128	/* Return the OID that we received */
7cac2b65	129	packet_put_string(doid, len);
23987cb8	130
7cac2b65	131	packet_send();
7cac2b65	132	xfree(doid);
b59afbfe	133
7cac2b65	134	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
	135	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
	136	authctxt->postponed = 1;
	137
	138	return (0);
b59afbfe	139	}
	140
	141	static void
	142	input_gssapi_token(int type, u_int32_t plen, void *ctxt)
	143	{
7cac2b65	144	Authctxt *authctxt = ctxt;
	145	Gssctxt *gssctxt;
	146	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	147	gss_buffer_desc recv_tok;
147c00cc	148	OM_uint32 maj_status, min_status, flags=0;
7cac2b65	149	u_int len;
	150
	151	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	152	fatal("No authentication or GSSAPI context");
	153
	154	gssctxt = authctxt->methoddata;
	155	recv_tok.value = packet_get_string(&len);
	156	recv_tok.length = len; /* u_int vs. size_t */
	157
	158	packet_check_eom();
	159
	160	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
540d72c3	161	&send_tok, &flags));
7cac2b65	162
	163	xfree(recv_tok.value);
	164
	165	if (GSS_ERROR(maj_status)) {
e23e524c	166	ssh_gssapi_userauth_error(gssctxt);
e23e524c	167	if (send_tok.length != 0) {
e23e524c	168	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
7cac2b65	169	packet_put_string(send_tok.value, send_tok.length);
	170	packet_send();
	171	}
	172	authctxt->postponed = 0;
7cac2b65	173	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
540d72c3	174	userauth_finish(authctxt, 0,
	175	gssapi_with_mic ? "gssapi-with-mic" :
	176	"gssapi");
7cac2b65	177	} else {
7cac2b65	178	if (send_tok.length != 0) {
7cac2b65	179	packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
	180	packet_put_string(send_tok.value, send_tok.length);
	181	packet_send();
	182	}
	183	if (maj_status == GSS_S_COMPLETE) {
7cac2b65	184	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
540d72c3	185	if (flags & GSS_C_INTEG_FLAG && gssapi_with_mic)
	186	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
	187	&input_gssapi_mic);
	188	else
	189	dispatch_set(
	190	SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
	191	&input_gssapi_exchange_complete);
7cac2b65	192	}
	193	}
	194
	195	gss_release_buffer(&min_status, &send_tok);
e23e524c	196	}
23987cb8	197
e23e524c	198	static void
	199	input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
	200	{
7cac2b65	201	Authctxt *authctxt = ctxt;
	202	Gssctxt *gssctxt;
	203	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	204	gss_buffer_desc recv_tok;
	205	OM_uint32 maj_status;
	206	u_int len;
	207
	208	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	209	fatal("No authentication or GSSAPI context");
	210
	211	gssctxt = authctxt->methoddata;
	212	recv_tok.value = packet_get_string(&len);
	213	recv_tok.length = len;
	214
	215	packet_check_eom();
	216
	217	/* Push the error token into GSSAPI to see what it says */
	218	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	219	&send_tok, NULL));
	220
	221	xfree(recv_tok.value);
e23e524c	222
e23e524c	223	/* We can't return anything to the client, even if we wanted to */
e23e524c	224	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
7cac2b65	225	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
e23e524c	226
e23e524c	227	/* The client will have already moved on to the next auth */
7cac2b65	228
7cac2b65	229	gss_release_buffer(&maj_status, &send_tok);
b59afbfe	230	}
b59afbfe	231
540d72c3	232	static void
	233	gssapi_set_implicit_username(Authctxt *authctxt)
	234	{
294206af	235	if ((authctxt->user == NULL) \|\| (strcmp(authctxt->user, "") == 0)) {
540d72c3	236	char *lname = NULL;
	237	PRIVSEP(ssh_gssapi_localname(&lname));
	238	if (lname && lname[0] != '\0') {
	239	xfree(authctxt->user);
	240	authctxt->user = lname;
	241	debug("set username to %s from gssapi context", lname);
	242	authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
5217e987	243	if (authctxt->pw) {
	244	authctxt->valid = 1;
	245	}
540d72c3	246	} else {
	247	debug("failed to set username from gssapi context");
	248	}
	249	}
	250	if (authctxt->pw) {
	251	#ifdef USE_PAM
147c00cc	252	if (options.use_pam)
5217e987	253	PRIVSEP(start_pam(authctxt));
540d72c3	254	#endif
	255	}
	256	}
	257
7cac2b65	258	/*
7cac2b65	259	* This is called when the client thinks we've completed authentication.
b59afbfe	260	* It should only be enabled in the dispatch handler by the function above,
	261	* which only enables it once the GSSAPI exchange is complete.
	262	*/
7cac2b65	263
b59afbfe	264	static void
	265	input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
	266	{
7cac2b65	267	Authctxt *authctxt = ctxt;
	268	Gssctxt *gssctxt;
	269	int authenticated;
	270
b59afbfe	271	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
7cac2b65	272	fatal("No authentication or GSSAPI context");
7cac2b65	273
540d72c3	274	gssapi_set_implicit_username(authctxt);
d13dfff4	275
7cac2b65	276	gssctxt = authctxt->methoddata;
7cac2b65	277
7cac2b65	278	/*
540d72c3	279	* We don't need to check the status, because we're only enabled in
540d72c3	280	* the dispatcher once the exchange is complete
b59afbfe	281	*/
b59afbfe	282
7cac2b65	283	packet_check_eom();
7cac2b65	284
5217e987	285	if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
540d72c3	286	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	287	} else {
	288	authenticated = 0;
	289	}
b59afbfe	290
7cac2b65	291	authctxt->postponed = 0;
	292	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	293	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
540d72c3	294	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
7cac2b65	295	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
540d72c3	296	userauth_finish(authctxt, authenticated,
	297	gssapi_with_mic ? "gssapi-with-mic" : "gssapi");
	298	}
	299
	300	static int
	301	userauth_gssapi_with_mic(Authctxt *authctxt)
	302	{
	303	gssapi_with_mic = 1;
	304	return userauth_gssapi(authctxt);
	305	}
	306
	307	static int
	308	userauth_gssapi_without_mic(Authctxt *authctxt)
	309	{
	310	gssapi_with_mic = 0;
	311	return userauth_gssapi(authctxt);
	312	}
	313
	314	static void
	315	input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
	316	{
	317	Authctxt *authctxt = ctxt;
	318	Gssctxt *gssctxt;
	319	int authenticated = 0;
	320	Buffer b;
	321	gss_buffer_desc mic, gssbuf;
	322	u_int len;
	323
	324	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	325	fatal("No authentication or GSSAPI context");
	326
	327	gssapi_set_implicit_username(authctxt);
	328
	329	gssctxt = authctxt->methoddata;
	330
	331	mic.value = packet_get_string(&len);
	332	mic.length = len;
	333
	334	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	335	"gssapi-with-mic");
	336
	337	gssbuf.value = buffer_ptr(&b);
	338	gssbuf.length = buffer_len(&b);
	339
	340	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
5217e987	341	if (authctxt->valid && strcmp(authctxt->user, "") != 0) {
540d72c3	342	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	343	} else {
	344	authenticated = 0;
	345	}
	346	else
	347	logit("GSSAPI MIC check failed");
	348
	349	buffer_free(&b);
	350	xfree(mic.value);
	351
	352	authctxt->postponed = 0;
	353	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	354	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	355	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	356	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	357	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
b59afbfe	358	}
b59afbfe	359
23987cb8	360	static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
	361	char *errstr;
	362	OM_uint32 maj,min;
	363
	364	errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
	365	if (errstr) {
	366	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
	367	packet_put_int(maj);
	368	packet_put_int(min);
	369	packet_put_cstring(errstr);
	370	packet_put_cstring("");
	371	packet_send();
	372	packet_write_wait();
	373	xfree(errstr);
	374	}
	375	}
	376
b59afbfe	377	Authmethod method_external = {
	378	"external-keyx",
	379	userauth_external,
	380	&options.gss_authentication
	381	};
	382
	383	Authmethod method_gssapi = {
540d72c3	384	"gssapi-with-mic",
	385	userauth_gssapi_with_mic,
	386	&options.gss_authentication
	387	};
	388
	389	Authmethod method_gssapi_compat = {
7cac2b65	390	"gssapi",
540d72c3	391	userauth_gssapi_without_mic,
7cac2b65	392	&options.gss_authentication
b59afbfe	393	};
	394
	395	#endif /* GSSAPI */