[openssh.git] / gss-genr.c

/* $OpenBSD: gss-genr.c,v 1.12 2006/07/26 02:35:17 stevesk 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 <sys/param.h>

#include <string.h>
#include <unistd.h>

#include "xmalloc.h"
#include "bufaux.h"
#include "log.h"
#include "ssh2.h"

#include "ssh-gss.h"

extern u_char *session_id2;
extern u_int session_id2_len;

/* Check that the OID in a data stream matches that in the context */
int
ssh_gssapi_check_oid(Gssctxt *ctx, void *data, size_t len)
{
	return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
	    ctx->oid->length == len &&
	    memcmp(ctx->oid->elements, data, len) == 0);
}

/* Set the contexts OID from a data stream */
void
ssh_gssapi_set_oid_data(Gssctxt *ctx, void *data, size_t len)
{
	if (ctx->oid != GSS_C_NO_OID) {
		xfree(ctx->oid->elements);
		xfree(ctx->oid);
	}
	ctx->oid = xmalloc(sizeof(gss_OID_desc));
	ctx->oid->length = len;
	ctx->oid->elements = xmalloc(len);
	memcpy(ctx->oid->elements, data, len);
}

/* Set the contexts OID */
void
ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
{
	ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
}

/* All this effort to report an error ... */
void
ssh_gssapi_error(Gssctxt *ctxt)
{
	char *s;

	s = ssh_gssapi_last_error(ctxt, NULL, NULL);
	debug("%s", s);
	xfree(s);
}

char *
ssh_gssapi_last_error(Gssctxt *ctxt, OM_uint32 *major_status,
    OM_uint32 *minor_status)
{
	OM_uint32 lmin;
	gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
	OM_uint32 ctx;
	Buffer b;
	char *ret;

	buffer_init(&b);

	if (major_status != NULL)
		*major_status = ctxt->major;
	if (minor_status != NULL)
		*minor_status = ctxt->minor;

	ctx = 0;
	/* The GSSAPI error */
	do {
		gss_display_status(&lmin, ctxt->major,
		    GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);

		buffer_append(&b, msg.value, msg.length);
		buffer_put_char(&b, '\n');

		gss_release_buffer(&lmin, &msg);
	} while (ctx != 0);

	/* The mechanism specific error */
	do {
		gss_display_status(&lmin, ctxt->minor,
		    GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);

		buffer_append(&b, msg.value, msg.length);
		buffer_put_char(&b, '\n');

		gss_release_buffer(&lmin, &msg);
	} while (ctx != 0);

	buffer_put_char(&b, '\0');
	ret = xmalloc(buffer_len(&b));
	buffer_get(&b, ret, buffer_len(&b));
	buffer_free(&b);
	return (ret);
}

/*
 * Initialise our GSSAPI context. We use this opaque structure to contain all
 * of the data which both the client and server need to persist across
 * {accept,init}_sec_context calls, so that when we do it from the userauth
 * stuff life is a little easier
 */
void
ssh_gssapi_build_ctx(Gssctxt **ctx)
{
	*ctx = xcalloc(1, sizeof (Gssctxt));
	(*ctx)->context = GSS_C_NO_CONTEXT;
	(*ctx)->name = GSS_C_NO_NAME;
	(*ctx)->oid = GSS_C_NO_OID;
	(*ctx)->creds = GSS_C_NO_CREDENTIAL;
	(*ctx)->client = GSS_C_NO_NAME;
	(*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
}

/* Delete our context, providing it has been built correctly */
void
ssh_gssapi_delete_ctx(Gssctxt **ctx)
{
	OM_uint32 ms;

	if ((*ctx) == NULL)
		return;
	if ((*ctx)->context != GSS_C_NO_CONTEXT)
		gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
	if ((*ctx)->name != GSS_C_NO_NAME)
		gss_release_name(&ms, &(*ctx)->name);
	if ((*ctx)->oid != GSS_C_NO_OID) {
		xfree((*ctx)->oid->elements);
		xfree((*ctx)->oid);
		(*ctx)->oid = GSS_C_NO_OID;
	}
	if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
		gss_release_cred(&ms, &(*ctx)->creds);
	if ((*ctx)->client != GSS_C_NO_NAME)
		gss_release_name(&ms, &(*ctx)->client);
	if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
		gss_release_cred(&ms, &(*ctx)->client_creds);

	xfree(*ctx);
	*ctx = NULL;
}

/*
 * Wrapper to init_sec_context
 * Requires that the context contains:
 *	oid
 *	server name (from ssh_gssapi_import_name)
 */
OM_uint32
ssh_gssapi_init_ctx(Gssctxt *ctx, int deleg_creds, gss_buffer_desc *recv_tok,
    gss_buffer_desc* send_tok, OM_uint32 *flags)
{
	int deleg_flag = 0;

	if (deleg_creds) {
		deleg_flag = GSS_C_DELEG_FLAG;
		debug("Delegating credentials");
	}

	ctx->major = gss_init_sec_context(&ctx->minor,
	    GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
	    GSS_C_MUTUAL_FLAG | GSS_C_INTEG_FLAG | deleg_flag,
	    0, NULL, recv_tok, NULL, send_tok, flags, NULL);

	if (GSS_ERROR(ctx->major))
		ssh_gssapi_error(ctx);

	return (ctx->major);
}

/* Create a service name for the given host */
OM_uint32
ssh_gssapi_import_name(Gssctxt *ctx, const char *host)
{
	gss_buffer_desc gssbuf;
	char *val;

	xasprintf(&val, "host@%s", host);
	gssbuf.value = val;
	gssbuf.length = strlen(gssbuf.value);

	if ((ctx->major = gss_import_name(&ctx->minor,
	    &gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
		ssh_gssapi_error(ctx);

	xfree(gssbuf.value);
	return (ctx->major);
}

/* Acquire credentials for a server running on the current host.
 * Requires that the context structure contains a valid OID
 */

/* Returns a GSSAPI error code */
OM_uint32
ssh_gssapi_acquire_cred(Gssctxt *ctx)
{
	OM_uint32 status;
	char lname[MAXHOSTNAMELEN];
	gss_OID_set oidset;

	gss_create_empty_oid_set(&status, &oidset);
	gss_add_oid_set_member(&status, ctx->oid, &oidset);

	if (gethostname(lname, MAXHOSTNAMELEN)) {
		gss_release_oid_set(&status, &oidset);
		return (-1);
	}

	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
		gss_release_oid_set(&status, &oidset);
		return (ctx->major);
	}

	if ((ctx->major = gss_acquire_cred(&ctx->minor,
	    ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
		ssh_gssapi_error(ctx);

	gss_release_oid_set(&status, &oidset);
	return (ctx->major);
}

OM_uint32
ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
{
	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
	    GSS_C_QOP_DEFAULT, buffer, hash)))
		ssh_gssapi_error(ctx);

	return (ctx->major);
}

void
ssh_gssapi_buildmic(Buffer *b, const char *user, const char *service,
    const char *context)
{
	buffer_init(b);
	buffer_put_string(b, session_id2, session_id2_len);
	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
	buffer_put_cstring(b, user);
	buffer_put_cstring(b, service);
	buffer_put_cstring(b, context);
}

OM_uint32
ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
{
	if (*ctx)
		ssh_gssapi_delete_ctx(ctx);
	ssh_gssapi_build_ctx(ctx);
	ssh_gssapi_set_oid(*ctx, oid);
	return (ssh_gssapi_acquire_cred(*ctx));
}

#endif /* GSSAPI */
Commit	Line	Data
536c14e8	1	/* $OpenBSD: gss-genr.c,v 1.12 2006/07/26 02:35:17 stevesk Exp $ */
7364bd04	2
	3	/*
	4	* Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved.
	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
	30
536c14e8	31	#include <sys/param.h>
536c14e8	32
00146caa	33	#include <string.h>
28cb0a43	34	#include <unistd.h>
00146caa	35
7364bd04	36	#include "xmalloc.h"
7364bd04	37	#include "bufaux.h"
7364bd04	38	#include "log.h"
0789992b	39	#include "ssh2.h"
7364bd04	40
	41	#include "ssh-gss.h"
	42
0789992b	43	extern u_char *session_id2;
0789992b	44	extern u_int session_id2_len;
7364bd04	45
	46	/* Check that the OID in a data stream matches that in the context */
	47	int
	48	ssh_gssapi_check_oid(Gssctxt ctx, void data, size_t len)
	49	{
	50	return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
	51	ctx->oid->length == len &&
	52	memcmp(ctx->oid->elements, data, len) == 0);
	53	}
	54
	55	/* Set the contexts OID from a data stream */
	56	void
	57	ssh_gssapi_set_oid_data(Gssctxt ctx, void data, size_t len)
	58	{
	59	if (ctx->oid != GSS_C_NO_OID) {
	60	xfree(ctx->oid->elements);
	61	xfree(ctx->oid);
	62	}
	63	ctx->oid = xmalloc(sizeof(gss_OID_desc));
	64	ctx->oid->length = len;
	65	ctx->oid->elements = xmalloc(len);
	66	memcpy(ctx->oid->elements, data, len);
	67	}
	68
	69	/* Set the contexts OID */
	70	void
	71	ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
	72	{
	73	ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
	74	}
	75
	76	/* All this effort to report an error ... */
	77	void
	78	ssh_gssapi_error(Gssctxt *ctxt)
	79	{
0926fd19	80	char *s;
	81
	82	s = ssh_gssapi_last_error(ctxt, NULL, NULL);
	83	debug("%s", s);
	84	xfree(s);
7364bd04	85	}
	86
	87	char *
4e2e5cfd	88	ssh_gssapi_last_error(Gssctxt ctxt, OM_uint32 major_status,
4e2e5cfd	89	OM_uint32 *minor_status)
7364bd04	90	{
	91	OM_uint32 lmin;
	92	gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
	93	OM_uint32 ctx;
	94	Buffer b;
	95	char *ret;
	96
	97	buffer_init(&b);
	98
	99	if (major_status != NULL)
	100	*major_status = ctxt->major;
	101	if (minor_status != NULL)
	102	*minor_status = ctxt->minor;
	103
	104	ctx = 0;
	105	/* The GSSAPI error */
	106	do {
	107	gss_display_status(&lmin, ctxt->major,
	108	GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
	109
	110	buffer_append(&b, msg.value, msg.length);
	111	buffer_put_char(&b, '\n');
	112
	113	gss_release_buffer(&lmin, &msg);
	114	} while (ctx != 0);
	115
	116	/* The mechanism specific error */
	117	do {
	118	gss_display_status(&lmin, ctxt->minor,
	119	GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
	120
	121	buffer_append(&b, msg.value, msg.length);
	122	buffer_put_char(&b, '\n');
	123
	124	gss_release_buffer(&lmin, &msg);
	125	} while (ctx != 0);
	126
	127	buffer_put_char(&b, '\0');
	128	ret = xmalloc(buffer_len(&b));
	129	buffer_get(&b, ret, buffer_len(&b));
	130	buffer_free(&b);
	131	return (ret);
	132	}
	133
	134	/*
	135	* Initialise our GSSAPI context. We use this opaque structure to contain all
	136	* of the data which both the client and server need to persist across
	137	* {accept,init}_sec_context calls, so that when we do it from the userauth
	138	* stuff life is a little easier
	139	*/
	140	void
	141	ssh_gssapi_build_ctx(Gssctxt **ctx)
	142	{
52e3daed	143	*ctx = xcalloc(1, sizeof (Gssctxt));
7364bd04	144	(*ctx)->context = GSS_C_NO_CONTEXT;
	145	(*ctx)->name = GSS_C_NO_NAME;
	146	(*ctx)->oid = GSS_C_NO_OID;
	147	(*ctx)->creds = GSS_C_NO_CREDENTIAL;
	148	(*ctx)->client = GSS_C_NO_NAME;
	149	(*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
	150	}
	151
	152	/* Delete our context, providing it has been built correctly */
	153	void
	154	ssh_gssapi_delete_ctx(Gssctxt **ctx)
	155	{
	156	OM_uint32 ms;
	157
	158	if ((*ctx) == NULL)
	159	return;
	160	if ((*ctx)->context != GSS_C_NO_CONTEXT)
	161	gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
	162	if ((*ctx)->name != GSS_C_NO_NAME)
	163	gss_release_name(&ms, &(*ctx)->name);
	164	if ((*ctx)->oid != GSS_C_NO_OID) {
	165	xfree((*ctx)->oid->elements);
	166	xfree((*ctx)->oid);
	167	(*ctx)->oid = GSS_C_NO_OID;
	168	}
	169	if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
	170	gss_release_cred(&ms, &(*ctx)->creds);
	171	if ((*ctx)->client != GSS_C_NO_NAME)
	172	gss_release_name(&ms, &(*ctx)->client);
	173	if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
	174	gss_release_cred(&ms, &(*ctx)->client_creds);
	175
	176	xfree(*ctx);
	177	*ctx = NULL;
	178	}
	179
	180	/*
	181	* Wrapper to init_sec_context
	182	* Requires that the context contains:
	183	* oid
	184	* server name (from ssh_gssapi_import_name)
	185	*/
	186	OM_uint32
	187	ssh_gssapi_init_ctx(Gssctxt ctx, int deleg_creds, gss_buffer_desc recv_tok,
	188	gss_buffer_desc* send_tok, OM_uint32 *flags)
	189	{
	190	int deleg_flag = 0;
	191
	192	if (deleg_creds) {
	193	deleg_flag = GSS_C_DELEG_FLAG;
	194	debug("Delegating credentials");
	195	}
	196
	197	ctx->major = gss_init_sec_context(&ctx->minor,
	198	GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
	199	GSS_C_MUTUAL_FLAG \| GSS_C_INTEG_FLAG \| deleg_flag,
	200	0, NULL, recv_tok, NULL, send_tok, flags, NULL);
	201
	202	if (GSS_ERROR(ctx->major))
	203	ssh_gssapi_error(ctx);
	204
	205	return (ctx->major);
	206	}
	207
208	/* Create a service name for the given host */
209	OM_uint32
210	ssh_gssapi_import_name(Gssctxt ctx, const char host)
211	{
212	gss_buffer_desc gssbuf;
9c3c8eb1	213	char *val;
7364bd04	214
9c3c8eb1	215	xasprintf(&val, "host@%s", host);
	216	gssbuf.value = val;
	217	gssbuf.length = strlen(gssbuf.value);
7364bd04	218
	219	if ((ctx->major = gss_import_name(&ctx->minor,
	220	&gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
	221	ssh_gssapi_error(ctx);
	222
	223	xfree(gssbuf.value);
	224	return (ctx->major);
	225	}
	226
	227	/* Acquire credentials for a server running on the current host.
	228	* Requires that the context structure contains a valid OID
	229	*/
	230
	231	/* Returns a GSSAPI error code */
	232	OM_uint32
	233	ssh_gssapi_acquire_cred(Gssctxt *ctx)
	234	{
	235	OM_uint32 status;
	236	char lname[MAXHOSTNAMELEN];
	237	gss_OID_set oidset;
	238
	239	gss_create_empty_oid_set(&status, &oidset);
	240	gss_add_oid_set_member(&status, ctx->oid, &oidset);
	241
0926fd19	242	if (gethostname(lname, MAXHOSTNAMELEN)) {
0926fd19	243	gss_release_oid_set(&status, &oidset);
7364bd04	244	return (-1);
0926fd19	245	}
7364bd04	246
0926fd19	247	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
0926fd19	248	gss_release_oid_set(&status, &oidset);
7364bd04	249	return (ctx->major);
0926fd19	250	}
7364bd04	251
	252	if ((ctx->major = gss_acquire_cred(&ctx->minor,
	253	ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
	254	ssh_gssapi_error(ctx);
	255
	256	gss_release_oid_set(&status, &oidset);
	257	return (ctx->major);
	258	}
	259
0789992b	260	OM_uint32
	261	ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
	262	{
	263	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
	264	GSS_C_QOP_DEFAULT, buffer, hash)))
	265	ssh_gssapi_error(ctx);
b6453d99	266
0789992b	267	return (ctx->major);
	268	}
	269
	270	void
aff51935	271	ssh_gssapi_buildmic(Buffer b, const char user, const char *service,
aff51935	272	const char *context)
b6453d99	273	{
0789992b	274	buffer_init(b);
	275	buffer_put_string(b, session_id2, session_id2_len);
	276	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
	277	buffer_put_cstring(b, user);
	278	buffer_put_cstring(b, service);
	279	buffer_put_cstring(b, context);
	280	}
	281
7364bd04	282	OM_uint32
8442cc66	283	ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
8442cc66	284	{
7364bd04	285	if (*ctx)
	286	ssh_gssapi_delete_ctx(ctx);
	287	ssh_gssapi_build_ctx(ctx);
	288	ssh_gssapi_set_oid(*ctx, oid);
	289	return (ssh_gssapi_acquire_cred(*ctx));
	290	}
	291
	292	#endif /* GSSAPI */