[openssh.git] / gss-genr.c

/*	$OpenBSD: gss-genr.c,v 1.7 2006/03/20 04:07:49 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 "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 = xmalloc(sizeof (Gssctxt));
	(*ctx)->major = 0;
	(*ctx)->minor = 0;
	(*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;

	gssbuf.length = sizeof("host@") + strlen(host);
	gssbuf.value = xmalloc(gssbuf.length);
	snprintf(gssbuf.value, gssbuf.length, "host@%s", host);

	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
0926fd19	1	/* $OpenBSD: gss-genr.c,v 1.7 2006/03/20 04:07:49 djm 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
	31	#include "xmalloc.h"
	32	#include "bufaux.h"
7364bd04	33	#include "log.h"
0789992b	34	#include "ssh2.h"
7364bd04	35
	36	#include "ssh-gss.h"
	37
0789992b	38	extern u_char *session_id2;
0789992b	39	extern u_int session_id2_len;
7364bd04	40
	41	/* Check that the OID in a data stream matches that in the context */
	42	int
	43	ssh_gssapi_check_oid(Gssctxt ctx, void data, size_t len)
	44	{
	45	return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
	46	ctx->oid->length == len &&
	47	memcmp(ctx->oid->elements, data, len) == 0);
	48	}
	49
	50	/* Set the contexts OID from a data stream */
	51	void
	52	ssh_gssapi_set_oid_data(Gssctxt ctx, void data, size_t len)
	53	{
	54	if (ctx->oid != GSS_C_NO_OID) {
	55	xfree(ctx->oid->elements);
	56	xfree(ctx->oid);
	57	}
	58	ctx->oid = xmalloc(sizeof(gss_OID_desc));
	59	ctx->oid->length = len;
	60	ctx->oid->elements = xmalloc(len);
	61	memcpy(ctx->oid->elements, data, len);
	62	}
	63
	64	/* Set the contexts OID */
	65	void
	66	ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
	67	{
	68	ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
	69	}
	70
	71	/* All this effort to report an error ... */
	72	void
	73	ssh_gssapi_error(Gssctxt *ctxt)
	74	{
0926fd19	75	char *s;
	76
	77	s = ssh_gssapi_last_error(ctxt, NULL, NULL);
	78	debug("%s", s);
	79	xfree(s);
7364bd04	80	}
	81
	82	char *
4e2e5cfd	83	ssh_gssapi_last_error(Gssctxt ctxt, OM_uint32 major_status,
4e2e5cfd	84	OM_uint32 *minor_status)
7364bd04	85	{
	86	OM_uint32 lmin;
	87	gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
	88	OM_uint32 ctx;
	89	Buffer b;
	90	char *ret;
	91
	92	buffer_init(&b);
	93
	94	if (major_status != NULL)
	95	*major_status = ctxt->major;
	96	if (minor_status != NULL)
	97	*minor_status = ctxt->minor;
	98
	99	ctx = 0;
	100	/* The GSSAPI error */
	101	do {
	102	gss_display_status(&lmin, ctxt->major,
	103	GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
	104
	105	buffer_append(&b, msg.value, msg.length);
	106	buffer_put_char(&b, '\n');
	107
	108	gss_release_buffer(&lmin, &msg);
	109	} while (ctx != 0);
	110
	111	/* The mechanism specific error */
	112	do {
	113	gss_display_status(&lmin, ctxt->minor,
	114	GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
	115
	116	buffer_append(&b, msg.value, msg.length);
	117	buffer_put_char(&b, '\n');
	118
	119	gss_release_buffer(&lmin, &msg);
	120	} while (ctx != 0);
	121
	122	buffer_put_char(&b, '\0');
	123	ret = xmalloc(buffer_len(&b));
	124	buffer_get(&b, ret, buffer_len(&b));
	125	buffer_free(&b);
	126	return (ret);
	127	}
	128
	129	/*
	130	* Initialise our GSSAPI context. We use this opaque structure to contain all
	131	* of the data which both the client and server need to persist across
	132	* {accept,init}_sec_context calls, so that when we do it from the userauth
	133	* stuff life is a little easier
	134	*/
	135	void
	136	ssh_gssapi_build_ctx(Gssctxt **ctx)
	137	{
	138	*ctx = xmalloc(sizeof (Gssctxt));
	139	(*ctx)->major = 0;
	140	(*ctx)->minor = 0;
	141	(*ctx)->context = GSS_C_NO_CONTEXT;
	142	(*ctx)->name = GSS_C_NO_NAME;
	143	(*ctx)->oid = GSS_C_NO_OID;
	144	(*ctx)->creds = GSS_C_NO_CREDENTIAL;
	145	(*ctx)->client = GSS_C_NO_NAME;
	146	(*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
	147	}
	148
149	/* Delete our context, providing it has been built correctly */
150	void
151	ssh_gssapi_delete_ctx(Gssctxt **ctx)
152	{
153	OM_uint32 ms;
154
155	if ((*ctx) == NULL)
156	return;
157	if ((*ctx)->context != GSS_C_NO_CONTEXT)
158	gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
159	if ((*ctx)->name != GSS_C_NO_NAME)
160	gss_release_name(&ms, &(*ctx)->name);
161	if ((*ctx)->oid != GSS_C_NO_OID) {
162	xfree((*ctx)->oid->elements);
163	xfree((*ctx)->oid);
164	(*ctx)->oid = GSS_C_NO_OID;
165	}
166	if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
167	gss_release_cred(&ms, &(*ctx)->creds);
168	if ((*ctx)->client != GSS_C_NO_NAME)
169	gss_release_name(&ms, &(*ctx)->client);
170	if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
171	gss_release_cred(&ms, &(*ctx)->client_creds);
172
173	xfree(*ctx);
174	*ctx = NULL;
175	}
176
177	/*
178	* Wrapper to init_sec_context
179	* Requires that the context contains:
180	* oid
181	* server name (from ssh_gssapi_import_name)
182	*/
183	OM_uint32
184	ssh_gssapi_init_ctx(Gssctxt ctx, int deleg_creds, gss_buffer_desc recv_tok,
185	gss_buffer_desc* send_tok, OM_uint32 *flags)
186	{
187	int deleg_flag = 0;
188
189	if (deleg_creds) {
190	deleg_flag = GSS_C_DELEG_FLAG;
191	debug("Delegating credentials");
192	}
193
194	ctx->major = gss_init_sec_context(&ctx->minor,
195	GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
196	GSS_C_MUTUAL_FLAG \| GSS_C_INTEG_FLAG \| deleg_flag,
197	0, NULL, recv_tok, NULL, send_tok, flags, NULL);
198
199	if (GSS_ERROR(ctx->major))
200	ssh_gssapi_error(ctx);
201
202	return (ctx->major);
203	}
204
205	/* Create a service name for the given host */
206	OM_uint32
207	ssh_gssapi_import_name(Gssctxt ctx, const char host)
208	{
209	gss_buffer_desc gssbuf;
210
211	gssbuf.length = sizeof("host@") + strlen(host);
212	gssbuf.value = xmalloc(gssbuf.length);
213	snprintf(gssbuf.value, gssbuf.length, "host@%s", host);
214
215	if ((ctx->major = gss_import_name(&ctx->minor,
216	&gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
217	ssh_gssapi_error(ctx);
218
219	xfree(gssbuf.value);
220	return (ctx->major);
221	}
222
223	/* Acquire credentials for a server running on the current host.
224	* Requires that the context structure contains a valid OID
225	*/
226
227	/* Returns a GSSAPI error code */
228	OM_uint32
229	ssh_gssapi_acquire_cred(Gssctxt *ctx)
230	{
231	OM_uint32 status;
232	char lname[MAXHOSTNAMELEN];
233	gss_OID_set oidset;
234
235	gss_create_empty_oid_set(&status, &oidset);
236	gss_add_oid_set_member(&status, ctx->oid, &oidset);
237
0926fd19	238	if (gethostname(lname, MAXHOSTNAMELEN)) {
0926fd19	239	gss_release_oid_set(&status, &oidset);
7364bd04	240	return (-1);
0926fd19	241	}
7364bd04	242
0926fd19	243	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
0926fd19	244	gss_release_oid_set(&status, &oidset);
7364bd04	245	return (ctx->major);
0926fd19	246	}
7364bd04	247
	248	if ((ctx->major = gss_acquire_cred(&ctx->minor,
	249	ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
	250	ssh_gssapi_error(ctx);
	251
	252	gss_release_oid_set(&status, &oidset);
	253	return (ctx->major);
	254	}
	255
0789992b	256	OM_uint32
	257	ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
	258	{
	259	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
	260	GSS_C_QOP_DEFAULT, buffer, hash)))
	261	ssh_gssapi_error(ctx);
b6453d99	262
0789992b	263	return (ctx->major);
	264	}
	265
	266	void
aff51935	267	ssh_gssapi_buildmic(Buffer b, const char user, const char *service,
aff51935	268	const char *context)
b6453d99	269	{
0789992b	270	buffer_init(b);
	271	buffer_put_string(b, session_id2, session_id2_len);
	272	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
	273	buffer_put_cstring(b, user);
	274	buffer_put_cstring(b, service);
	275	buffer_put_cstring(b, context);
	276	}
	277
7364bd04	278	OM_uint32
8442cc66	279	ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
8442cc66	280	{
7364bd04	281	if (*ctx)
	282	ssh_gssapi_delete_ctx(ctx);
	283	ssh_gssapi_build_ctx(ctx);
	284	ssh_gssapi_set_oid(*ctx, oid);
	285	return (ssh_gssapi_acquire_cred(*ctx));
	286	}
	287
	288	#endif /* GSSAPI */