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

/*	$OpenBSD: auth2-gss.c,v 1.7 2003/11/21 11:57:03 djm 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 int
userauth_external(Authctxt *authctxt)
{
        packet_check_eom();

        return(PRIVSEP(ssh_gssapi_userok(authctxt->user)));
}

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" */

/*
 * 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 oid = {0, NULL};
	Gssctxt *ctxt = NULL;
	int mechs;
	gss_OID_set supported;
	int present;
	OM_uint32 ms;
	u_int len;
	char *doid = NULL;

	if (!authctxt->valid || 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");
			oid.elements = doid;
			oid.length = len;
		} else {
			oid.elements = doid + 2;
			oid.length   = len - 2;
		}
		gss_test_oid_set_member(&ms, &oid, 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, &oid)))) {
		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 ((strcmp(authctxt->user, "") == 0) && (authctxt->pw == NULL)) {
	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));
	} else {
	    debug("failed to set username from gssapi context");
	}
    }
    if (authctxt->pw) {
#ifdef USE_PAM
	if (options.use_pam)
		PRIVSEP(start_pam(authctxt->pw->pw_name));
#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 (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 (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
416fd2a8	1	/* $OpenBSD: auth2-gss.c,v 1.7 2003/11/21 11:57:03 djm Exp $ */
70791e56	2
ff2d7a98	3	/*
88928908	4	* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
ff2d7a98	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
70791e56	30
ff2d7a98	31	#include "auth.h"
ff2d7a98	32	#include "ssh2.h"
ff2d7a98	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;
ff2d7a98	44
	45	static int
	46	userauth_external(Authctxt *authctxt)
	47	{
	48	packet_check_eom();
	49
	50	return(PRIVSEP(ssh_gssapi_userok(authctxt->user)));
	51	}
	52
88928908	53	static void ssh_gssapi_userauth_error(Gssctxt *ctxt);
ff2d7a98	54	static void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
416fd2a8	55	static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
ff2d7a98	56	static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
88928908	57	static void input_gssapi_errtok(int, u_int32_t, void *);
ff2d7a98	58
416fd2a8	59	static int gssapi_with_mic = 1; /* flag to toggle "gssapi-with-mic" vs.
	60	"gssapi" */
	61
70791e56	62	/*
70791e56	63	* We only support those mechanisms that we know about (ie ones that we know
ff2d7a98	64	* how to check local user kuserok and the like
	65	*/
	66	static int
	67	userauth_gssapi(Authctxt *authctxt)
	68	{
70791e56	69	gss_OID_desc oid = {0, NULL};
	70	Gssctxt *ctxt = NULL;
	71	int mechs;
	72	gss_OID_set supported;
	73	int present;
	74	OM_uint32 ms;
	75	u_int len;
	76	char *doid = NULL;
	77
	78	if (!authctxt->valid \|\| authctxt->user == NULL)
	79	return (0);
	80
	81	mechs = packet_get_int();
	82	if (mechs == 0) {
	83	debug("Mechanism negotiation is not supported");
	84	return (0);
88928908	85	}
ff2d7a98	86
70791e56	87	ssh_gssapi_supported_oids(&supported);
	88	do {
	89	mechs--;
ff2d7a98	90
70791e56	91	if (doid)
70791e56	92	xfree(doid);
88928908	93
416fd2a8	94	present = 0;
70791e56	95	doid = packet_get_string(&len);
88928908	96
70791e56	97	if (doid[0] != SSH_GSS_OIDTYPE \|\| doid[1] != len-2) {
	98	logit("Mechanism OID received using the old encoding form");
	99	oid.elements = doid;
	100	oid.length = len;
	101	} else {
	102	oid.elements = doid + 2;
	103	oid.length = len - 2;
	104	}
	105	gss_test_oid_set_member(&ms, &oid, supported, &present);
	106	} while (mechs > 0 && !present);
	107
	108	gss_release_oid_set(&ms, &supported);
	109
	110	if (!present) {
	111	xfree(doid);
	112	return (0);
	113	}
	114
	115	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &oid)))) {
	116	xfree(doid);
	117	return (0);
	118	}
	119
	120	authctxt->methoddata=(void *)ctxt;
	121
	122	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
	123
416fd2a8	124	/* Return the OID that we received */
70791e56	125	packet_put_string(doid, len);
88928908	126
70791e56	127	packet_send();
	128	xfree(doid);
	129
	130	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
	131	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
	132	authctxt->postponed = 1;
	133
	134	return (0);
ff2d7a98	135	}
	136
	137	static void
	138	input_gssapi_token(int type, u_int32_t plen, void *ctxt)
	139	{
70791e56	140	Authctxt *authctxt = ctxt;
	141	Gssctxt *gssctxt;
	142	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	143	gss_buffer_desc recv_tok;
2a304a95	144	OM_uint32 maj_status, min_status, flags=0;
70791e56	145	u_int len;
	146
	147	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	148	fatal("No authentication or GSSAPI context");
	149
	150	gssctxt = authctxt->methoddata;
	151	recv_tok.value = packet_get_string(&len);
	152	recv_tok.length = len; /* u_int vs. size_t */
	153
	154	packet_check_eom();
	155
	156	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
416fd2a8	157	&send_tok, &flags));
70791e56	158
	159	xfree(recv_tok.value);
	160
	161	if (GSS_ERROR(maj_status)) {
88928908	162	ssh_gssapi_userauth_error(gssctxt);
88928908	163	if (send_tok.length != 0) {
88928908	164	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
70791e56	165	packet_put_string(send_tok.value, send_tok.length);
	166	packet_send();
	167	}
	168	authctxt->postponed = 0;
	169	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
416fd2a8	170	userauth_finish(authctxt, 0,
	171	gssapi_with_mic ? "gssapi-with-mic" :
	172	"gssapi");
70791e56	173	} else {
	174	if (send_tok.length != 0) {
	175	packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
	176	packet_put_string(send_tok.value, send_tok.length);
	177	packet_send();
	178	}
	179	if (maj_status == GSS_S_COMPLETE) {
	180	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
416fd2a8	181	if (flags & GSS_C_INTEG_FLAG && gssapi_with_mic)
	182	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
	183	&input_gssapi_mic);
	184	else
	185	dispatch_set(
	186	SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
	187	&input_gssapi_exchange_complete);
70791e56	188	}
	189	}
	190
	191	gss_release_buffer(&min_status, &send_tok);
88928908	192	}
	193
	194	static void
	195	input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
	196	{
70791e56	197	Authctxt *authctxt = ctxt;
	198	Gssctxt *gssctxt;
	199	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	200	gss_buffer_desc recv_tok;
	201	OM_uint32 maj_status;
	202	u_int len;
	203
	204	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	205	fatal("No authentication or GSSAPI context");
	206
	207	gssctxt = authctxt->methoddata;
	208	recv_tok.value = packet_get_string(&len);
	209	recv_tok.length = len;
	210
	211	packet_check_eom();
	212
	213	/* Push the error token into GSSAPI to see what it says */
	214	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	215	&send_tok, NULL));
	216
	217	xfree(recv_tok.value);
88928908	218
88928908	219	/* We can't return anything to the client, even if we wanted to */
88928908	220	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
70791e56	221	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
88928908	222
88928908	223	/* The client will have already moved on to the next auth */
70791e56	224
70791e56	225	gss_release_buffer(&maj_status, &send_tok);
ff2d7a98	226	}
ff2d7a98	227
416fd2a8	228	static void
	229	gssapi_set_implicit_username(Authctxt *authctxt)
	230	{
	231	if ((strcmp(authctxt->user, "") == 0) && (authctxt->pw == NULL)) {
	232	char *lname = NULL;
	233	PRIVSEP(ssh_gssapi_localname(&lname));
	234	if (lname && lname[0] != '\0') {
	235	xfree(authctxt->user);
	236	authctxt->user = lname;
	237	debug("set username to %s from gssapi context", lname);
	238	authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
	239	} else {
	240	debug("failed to set username from gssapi context");
	241	}
	242	}
	243	if (authctxt->pw) {
	244	#ifdef USE_PAM
2a304a95	245	if (options.use_pam)
2a304a95	246	PRIVSEP(start_pam(authctxt->pw->pw_name));
416fd2a8	247	#endif
	248	}
	249	}
	250
70791e56	251	/*
70791e56	252	* This is called when the client thinks we've completed authentication.
ff2d7a98	253	* It should only be enabled in the dispatch handler by the function above,
	254	* which only enables it once the GSSAPI exchange is complete.
	255	*/
70791e56	256
ff2d7a98	257	static void
	258	input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
	259	{
70791e56	260	Authctxt *authctxt = ctxt;
	261	Gssctxt *gssctxt;
	262	int authenticated;
	263
ff2d7a98	264	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
70791e56	265	fatal("No authentication or GSSAPI context");
70791e56	266
416fd2a8	267	gssapi_set_implicit_username(authctxt);
c2397a66	268
70791e56	269	gssctxt = authctxt->methoddata;
ff2d7a98	270
70791e56	271	/*
416fd2a8	272	* We don't need to check the status, because we're only enabled in
416fd2a8	273	* the dispatcher once the exchange is complete
ff2d7a98	274	*/
ff2d7a98	275
70791e56	276	packet_check_eom();
70791e56	277
416fd2a8	278	if (strcmp(authctxt->user, "") != 0) {
	279	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	280	} else {
	281	authenticated = 0;
	282	}
ff2d7a98	283
70791e56	284	authctxt->postponed = 0;
	285	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	286	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
416fd2a8	287	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
70791e56	288	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
416fd2a8	289	userauth_finish(authctxt, authenticated,
	290	gssapi_with_mic ? "gssapi-with-mic" : "gssapi");
	291	}
	292
	293	static int
	294	userauth_gssapi_with_mic(Authctxt *authctxt)
	295	{
	296	gssapi_with_mic = 1;
	297	return userauth_gssapi(authctxt);
	298	}
	299
	300	static int
	301	userauth_gssapi_without_mic(Authctxt *authctxt)
	302	{
	303	gssapi_with_mic = 0;
	304	return userauth_gssapi(authctxt);
	305	}
	306
	307	static void
	308	input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
	309	{
	310	Authctxt *authctxt = ctxt;
	311	Gssctxt *gssctxt;
	312	int authenticated = 0;
	313	Buffer b;
	314	gss_buffer_desc mic, gssbuf;
	315	u_int len;
	316
	317	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	318	fatal("No authentication or GSSAPI context");
	319
	320	gssapi_set_implicit_username(authctxt);
	321
	322	gssctxt = authctxt->methoddata;
	323
	324	mic.value = packet_get_string(&len);
	325	mic.length = len;
	326
	327	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	328	"gssapi-with-mic");
	329
	330	gssbuf.value = buffer_ptr(&b);
	331	gssbuf.length = buffer_len(&b);
	332
	333	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
	334	if (strcmp(authctxt->user, "") != 0) {
	335	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user));
	336	} else {
	337	authenticated = 0;
	338	}
	339	else
	340	logit("GSSAPI MIC check failed");
	341
	342	buffer_free(&b);
	343	xfree(mic.value);
	344
	345	authctxt->postponed = 0;
	346	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	347	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	348	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	349	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	350	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
ff2d7a98	351	}
ff2d7a98	352
88928908	353	static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
	354	char *errstr;
	355	OM_uint32 maj,min;
	356
	357	errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
	358	if (errstr) {
88928908	359	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
	360	packet_put_int(maj);
	361	packet_put_int(min);
	362	packet_put_cstring(errstr);
	363	packet_put_cstring("");
	364	packet_send();
	365	packet_write_wait();
	366	xfree(errstr);
88928908	367	}
	368	}
	369
ff2d7a98	370	Authmethod method_external = {
	371	"external-keyx",
	372	userauth_external,
	373	&options.gss_authentication
	374	};
	375
	376	Authmethod method_gssapi = {
416fd2a8	377	"gssapi-with-mic",
	378	userauth_gssapi_with_mic,
	379	&options.gss_authentication
	380	};
	381
	382	Authmethod method_gssapi_compat = {
70791e56	383	"gssapi",
416fd2a8	384	userauth_gssapi_without_mic,
70791e56	385	&options.gss_authentication
ff2d7a98	386	};
	387
	388	#endif /* GSSAPI */