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

/* $OpenBSD: auth2-gss.c,v 1.16 2007/10/29 00:52:45 dtucker Exp $ */

/*
 * Copyright (c) 2001-2007 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 <sys/types.h>

#include <stdarg.h>

#include "xmalloc.h"
#include "key.h"
#include "hostfile.h"
#include "auth.h"
#include "ssh2.h"
#include "log.h"
#include "dispatch.h"
#include "buffer.h"
#include "servconf.h"
#include "packet.h"
#include "ssh-gss.h"
#include "monitor_wrap.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 *);

/* 
 * The 'gssapi_keyex' userauth mechanism.
 */
static int
userauth_gsskeyex(Authctxt *authctxt)
{
	int authenticated = 0;
	Buffer b, b2;
	gss_buffer_desc mic, gssbuf, gssbuf2;
	u_int len;

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

	packet_check_eom();

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

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

	/* client may have used empty username to determine target
	   name from GSSAPI context */
	ssh_gssapi_buildmic(&b2, "", authctxt->service, "gssapi-keyex");

	gssbuf2.value = buffer_ptr(&b2);
	gssbuf2.length = buffer_len(&b2);

	/* gss_kex_context is NULL with privsep, so we can't check it here */
	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
						   &gssbuf, &mic))) ||
	    !GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context, 
						   &gssbuf2, &mic)))) {
	    if (authctxt->valid && authctxt->user && authctxt->user[0]) {
            authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
                                                      authctxt->pw));
	    }
	}
	
	buffer_free(&b);
	buffer_free(&b2);
	xfree(mic.value);

	return (authenticated);
}

/*
 * 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;
	u_char *doid = NULL;

	/* authctxt->valid may be 0 if we haven't yet determined
	   username from gssapi context. */

	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 (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
		    doid[1] == len - 2) {
			goid.elements = doid + 2;
			goid.length   = len - 2;
			gss_test_oid_set_member(&ms, &goid, supported,
			    &present);
		} else {
			logit("Badly formed OID received");
		}
	} while (mechs > 0 && !present);

	gss_release_oid_set(&ms, &supported);

	if (!present) {
		xfree(doid);
		authctxt->server_caused_failure = 1;
		return (0);
	}

	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
		if (ctxt != NULL)
			ssh_gssapi_delete_ctx(&ctxt);
		xfree(doid);
		authctxt->server_caused_failure = 1;
		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");
	} 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)
				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_username(Authctxt *authctxt)
{
    char *lname = NULL;

    if ((authctxt->user == NULL) || (authctxt->user[0] == '\0')) {
        PRIVSEP(ssh_gssapi_localname(&lname));
        if (lname && lname[0] != '\0') {
            if (authctxt->user) 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;
#ifdef USE_PAM
                if (options.use_pam)
                    PRIVSEP(start_pam(authctxt));
#endif
            }
        } else {
            debug("failed to set username from gssapi context");
            packet_send_debug("failed to set username from gssapi context");
        }
    }
}

/*
 * 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_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();

	/* user should be set if valid but we double-check here */
	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
	    authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
                                                  authctxt->pw));
	} 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");
}

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");

	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);

    gssapi_set_username(authctxt);

	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
	    if (authctxt->valid && authctxt->user && authctxt->user[0]) {
            authenticated =
                PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
	    } 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_gsskeyex = {
	"gssapi-keyex",
	userauth_gsskeyex,
	&options.gss_authentication
};

Authmethod method_gssapi = {
	"gssapi-with-mic",
	userauth_gssapi,
	&options.gss_authentication
};

#endif /* GSSAPI */
Commit	Line	Data
e74dc197	1	/* $OpenBSD: auth2-gss.c,v 1.16 2007/10/29 00:52:45 dtucker Exp $ */
7cac2b65	2
b59afbfe	3	/*
f97edba6	4	* Copyright (c) 2001-2007 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
30460aeb	31	#include <sys/types.h>
	32
	33	#include <stdarg.h>
	34
	35	#include "xmalloc.h"
	36	#include "key.h"
	37	#include "hostfile.h"
b59afbfe	38	#include "auth.h"
b59afbfe	39	#include "ssh2.h"
b59afbfe	40	#include "log.h"
b59afbfe	41	#include "dispatch.h"
30460aeb	42	#include "buffer.h"
b59afbfe	43	#include "servconf.h"
b59afbfe	44	#include "packet.h"
b59afbfe	45	#include "ssh-gss.h"
30460aeb	46	#include "monitor_wrap.h"
b59afbfe	47
b59afbfe	48	extern ServerOptions options;
b59afbfe	49
23987cb8	50	static void ssh_gssapi_userauth_error(Gssctxt *ctxt);
b59afbfe	51	static void input_gssapi_token(int type, u_int32_t plen, void *ctxt);
540d72c3	52	static void input_gssapi_mic(int type, u_int32_t plen, void *ctxt);
b59afbfe	53	static void input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt);
e23e524c	54	static void input_gssapi_errtok(int, u_int32_t, void *);
b59afbfe	55
fe4ad273	56	/*
	57	* The 'gssapi_keyex' userauth mechanism.
	58	*/
	59	static int
	60	userauth_gsskeyex(Authctxt *authctxt)
	61	{
	62	int authenticated = 0;
	63	Buffer b, b2;
	64	gss_buffer_desc mic, gssbuf, gssbuf2;
	65	u_int len;
	66
	67	mic.value = packet_get_string(&len);
	68	mic.length = len;
	69
	70	packet_check_eom();
	71
	72	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	73	"gssapi-keyex");
	74
	75	gssbuf.value = buffer_ptr(&b);
	76	gssbuf.length = buffer_len(&b);
	77
	78	/* client may have used empty username to determine target
	79	name from GSSAPI context */
	80	ssh_gssapi_buildmic(&b2, "", authctxt->service, "gssapi-keyex");
	81
	82	gssbuf2.value = buffer_ptr(&b2);
	83	gssbuf2.length = buffer_len(&b2);
	84
	85	/* gss_kex_context is NULL with privsep, so we can't check it here */
	86	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
	87	&gssbuf, &mic))) \|\|
	88	!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gss_kex_context,
	89	&gssbuf2, &mic)))) {
	90	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
c7931c9a	91	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
c7931c9a	92	authctxt->pw));
fe4ad273	93	}
	94	}
	95
	96	buffer_free(&b);
	97	buffer_free(&b2);
	98	xfree(mic.value);
	99
	100	return (authenticated);
	101	}
	102
7cac2b65	103	/*
7cac2b65	104	* We only support those mechanisms that we know about (ie ones that we know
08822d99	105	* how to check local user kuserok and the like)
b59afbfe	106	*/
	107	static int
	108	userauth_gssapi(Authctxt *authctxt)
	109	{
7e82606e	110	gss_OID_desc goid = {0, NULL};
7cac2b65	111	Gssctxt *ctxt = NULL;
	112	int mechs;
	113	gss_OID_set supported;
	114	int present;
	115	OM_uint32 ms;
	116	u_int len;
2ce0bfe4	117	u_char *doid = NULL;
7cac2b65	118
941f3f29	119	/* authctxt->valid may be 0 if we haven't yet determined
	120	username from gssapi context. */
	121
5217e987	122	if (authctxt->user == NULL)
7cac2b65	123	return (0);
	124
	125	mechs = packet_get_int();
	126	if (mechs == 0) {
	127	debug("Mechanism negotiation is not supported");
	128	return (0);
	129	}
	130
	131	ssh_gssapi_supported_oids(&supported);
	132	do {
	133	mechs--;
	134
	135	if (doid)
	136	xfree(doid);
	137
540d72c3	138	present = 0;
7cac2b65	139	doid = packet_get_string(&len);
7cac2b65	140
2ce0bfe4	141	if (len > 2 && doid[0] == SSH_GSS_OIDTYPE &&
2ce0bfe4	142	doid[1] == len - 2) {
7e82606e	143	goid.elements = doid + 2;
7e82606e	144	goid.length = len - 2;
6fc2ad02	145	gss_test_oid_set_member(&ms, &goid, supported,
	146	&present);
	147	} else {
	148	logit("Badly formed OID received");
7cac2b65	149	}
7cac2b65	150	} while (mechs > 0 && !present);
	151
	152	gss_release_oid_set(&ms, &supported);
	153
	154	if (!present) {
	155	xfree(doid);
fe4ad273	156	authctxt->server_caused_failure = 1;
7cac2b65	157	return (0);
	158	}
	159
7e82606e	160	if (GSS_ERROR(PRIVSEP(ssh_gssapi_server_ctx(&ctxt, &goid)))) {
30460aeb	161	if (ctxt != NULL)
30460aeb	162	ssh_gssapi_delete_ctx(&ctxt);
7cac2b65	163	xfree(doid);
fe4ad273	164	authctxt->server_caused_failure = 1;
7cac2b65	165	return (0);
23987cb8	166	}
b59afbfe	167
08822d99	168	authctxt->methoddata = (void *)ctxt;
b59afbfe	169
7cac2b65	170	packet_start(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE);
23987cb8	171
540d72c3	172	/* Return the OID that we received */
7cac2b65	173	packet_put_string(doid, len);
23987cb8	174
7cac2b65	175	packet_send();
7cac2b65	176	xfree(doid);
b59afbfe	177
7cac2b65	178	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token);
	179	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok);
	180	authctxt->postponed = 1;
	181
	182	return (0);
b59afbfe	183	}
	184
	185	static void
	186	input_gssapi_token(int type, u_int32_t plen, void *ctxt)
	187	{
7cac2b65	188	Authctxt *authctxt = ctxt;
	189	Gssctxt *gssctxt;
	190	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	191	gss_buffer_desc recv_tok;
147c00cc	192	OM_uint32 maj_status, min_status, flags=0;
7cac2b65	193	u_int len;
	194
	195	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	196	fatal("No authentication or GSSAPI context");
	197
	198	gssctxt = authctxt->methoddata;
	199	recv_tok.value = packet_get_string(&len);
	200	recv_tok.length = len; /* u_int vs. size_t */
	201
	202	packet_check_eom();
	203
	204	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
540d72c3	205	&send_tok, &flags));
7cac2b65	206
	207	xfree(recv_tok.value);
	208
	209	if (GSS_ERROR(maj_status)) {
e23e524c	210	ssh_gssapi_userauth_error(gssctxt);
e23e524c	211	if (send_tok.length != 0) {
e23e524c	212	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK);
7cac2b65	213	packet_put_string(send_tok.value, send_tok.length);
	214	packet_send();
	215	}
	216	authctxt->postponed = 0;
7cac2b65	217	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
22ce3a3b	218	userauth_finish(authctxt, 0, "gssapi-with-mic");
7cac2b65	219	} else {
7cac2b65	220	if (send_tok.length != 0) {
7cac2b65	221	packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN);
	222	packet_put_string(send_tok.value, send_tok.length);
	223	packet_send();
	224	}
	225	if (maj_status == GSS_S_COMPLETE) {
7cac2b65	226	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
22ce3a3b	227	if (flags & GSS_C_INTEG_FLAG)
540d72c3	228	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC,
	229	&input_gssapi_mic);
	230	else
	231	dispatch_set(
	232	SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE,
	233	&input_gssapi_exchange_complete);
7cac2b65	234	}
	235	}
	236
	237	gss_release_buffer(&min_status, &send_tok);
e23e524c	238	}
23987cb8	239
e23e524c	240	static void
	241	input_gssapi_errtok(int type, u_int32_t plen, void *ctxt)
	242	{
7cac2b65	243	Authctxt *authctxt = ctxt;
	244	Gssctxt *gssctxt;
	245	gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
	246	gss_buffer_desc recv_tok;
	247	OM_uint32 maj_status;
	248	u_int len;
	249
	250	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	251	fatal("No authentication or GSSAPI context");
	252
	253	gssctxt = authctxt->methoddata;
	254	recv_tok.value = packet_get_string(&len);
	255	recv_tok.length = len;
	256
	257	packet_check_eom();
	258
	259	/* Push the error token into GSSAPI to see what it says */
	260	maj_status = PRIVSEP(ssh_gssapi_accept_ctx(gssctxt, &recv_tok,
	261	&send_tok, NULL));
	262
	263	xfree(recv_tok.value);
e23e524c	264
e23e524c	265	/* We can't return anything to the client, even if we wanted to */
e23e524c	266	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
7cac2b65	267	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
e23e524c	268
e23e524c	269	/* The client will have already moved on to the next auth */
7cac2b65	270
7cac2b65	271	gss_release_buffer(&maj_status, &send_tok);
b59afbfe	272	}
b59afbfe	273
540d72c3	274	static void
86a22a0a	275	gssapi_set_username(Authctxt *authctxt)
540d72c3	276	{
86a22a0a	277	char *lname = NULL;
86a22a0a	278
4f1e213f	279	if ((authctxt->user == NULL) \|\| (authctxt->user[0] == '\0')) {
86a22a0a	280	PRIVSEP(ssh_gssapi_localname(&lname));
	281	if (lname && lname[0] != '\0') {
	282	if (authctxt->user) xfree(authctxt->user);
	283	authctxt->user = lname;
	284	debug("set username to %s from gssapi context", lname);
	285	authctxt->pw = PRIVSEP(getpwnamallow(authctxt->user));
	286	if (authctxt->pw) {
	287	authctxt->valid = 1;
540d72c3	288	#ifdef USE_PAM
86a22a0a	289	if (options.use_pam)
86a22a0a	290	PRIVSEP(start_pam(authctxt));
540d72c3	291	#endif
86a22a0a	292	}
	293	} else {
	294	debug("failed to set username from gssapi context");
	295	packet_send_debug("failed to set username from gssapi context");
	296	}
540d72c3	297	}
	298	}
	299
7cac2b65	300	/*
7cac2b65	301	* This is called when the client thinks we've completed authentication.
b59afbfe	302	* It should only be enabled in the dispatch handler by the function above,
	303	* which only enables it once the GSSAPI exchange is complete.
	304	*/
7cac2b65	305
b59afbfe	306	static void
	307	input_gssapi_exchange_complete(int type, u_int32_t plen, void *ctxt)
	308	{
7cac2b65	309	Authctxt *authctxt = ctxt;
	310	Gssctxt *gssctxt;
	311	int authenticated;
	312
b59afbfe	313	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
7cac2b65	314	fatal("No authentication or GSSAPI context");
7cac2b65	315
3ea093c4	316	gssapi_set_username(authctxt);
d13dfff4	317
7cac2b65	318	gssctxt = authctxt->methoddata;
7cac2b65	319
7cac2b65	320	/*
540d72c3	321	* We don't need to check the status, because we're only enabled in
540d72c3	322	* the dispatcher once the exchange is complete
b59afbfe	323	*/
b59afbfe	324
7cac2b65	325	packet_check_eom();
7cac2b65	326
941f3f29	327	/* user should be set if valid but we double-check here */
941f3f29	328	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
c7931c9a	329	authenticated = PRIVSEP(ssh_gssapi_userok(authctxt->user,
c7931c9a	330	authctxt->pw));
540d72c3	331	} else {
	332	authenticated = 0;
	333	}
b59afbfe	334
7cac2b65	335	authctxt->postponed = 0;
	336	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	337	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
540d72c3	338	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
7cac2b65	339	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
22ce3a3b	340	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
540d72c3	341	}
	342
	343	static void
	344	input_gssapi_mic(int type, u_int32_t plen, void *ctxt)
	345	{
	346	Authctxt *authctxt = ctxt;
	347	Gssctxt *gssctxt;
	348	int authenticated = 0;
	349	Buffer b;
	350	gss_buffer_desc mic, gssbuf;
	351	u_int len;
	352
	353	if (authctxt == NULL \|\| (authctxt->methoddata == NULL && !use_privsep))
	354	fatal("No authentication or GSSAPI context");
	355
540d72c3	356	gssctxt = authctxt->methoddata;
	357
	358	mic.value = packet_get_string(&len);
	359	mic.length = len;
	360
	361	ssh_gssapi_buildmic(&b, authctxt->user, authctxt->service,
	362	"gssapi-with-mic");
	363
	364	gssbuf.value = buffer_ptr(&b);
	365	gssbuf.length = buffer_len(&b);
	366
86a22a0a	367	gssapi_set_username(authctxt);
86a22a0a	368
540d72c3	369	if (!GSS_ERROR(PRIVSEP(ssh_gssapi_checkmic(gssctxt, &gssbuf, &mic))))
941f3f29	370	if (authctxt->valid && authctxt->user && authctxt->user[0]) {
c7931c9a	371	authenticated =
c7931c9a	372	PRIVSEP(ssh_gssapi_userok(authctxt->user, authctxt->pw));
540d72c3	373	} else {
c7931c9a	374	authenticated = 0;
540d72c3	375	}
	376	else
	377	logit("GSSAPI MIC check failed");
	378
	379	buffer_free(&b);
	380	xfree(mic.value);
	381
	382	authctxt->postponed = 0;
	383	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, NULL);
	384	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, NULL);
	385	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_MIC, NULL);
	386	dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE, NULL);
	387	userauth_finish(authctxt, authenticated, "gssapi-with-mic");
b59afbfe	388	}
b59afbfe	389
23987cb8	390	static void ssh_gssapi_userauth_error(Gssctxt *ctxt) {
	391	char *errstr;
	392	OM_uint32 maj,min;
	393
	394	errstr=PRIVSEP(ssh_gssapi_last_error(ctxt,&maj,&min));
	395	if (errstr) {
	396	packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERROR);
	397	packet_put_int(maj);
	398	packet_put_int(min);
	399	packet_put_cstring(errstr);
	400	packet_put_cstring("");
	401	packet_send();
	402	packet_write_wait();
	403	xfree(errstr);
	404	}
	405	}
	406
fe4ad273	407	Authmethod method_gsskeyex = {
	408	"gssapi-keyex",
	409	userauth_gsskeyex,
	410	&options.gss_authentication
	411	};
	412
b59afbfe	413	Authmethod method_gssapi = {
540d72c3	414	"gssapi-with-mic",
22ce3a3b	415	userauth_gssapi,
7cac2b65	416	&options.gss_authentication
b59afbfe	417	};
	418
	419	#endif /* GSSAPI */