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

/*	$OpenBSD: gss-genr.c,v 1.6 2005/10/13 22:24:31 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 "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)
{
	debug("%s", ssh_gssapi_last_error(ctxt, NULL, NULL));
}

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))
		return (-1);

	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname)))
		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
2c06c99b	1	/* $OpenBSD: gss-genr.c,v 1.6 2005/10/13 22:24:31 stevesk Exp $ */
0fff78ff	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"
0fff78ff	33	#include "log.h"
cdd66111	34	#include "ssh2.h"
0fff78ff	35
	36	#include "ssh-gss.h"
	37
cdd66111	38	extern u_char *session_id2;
cdd66111	39	extern u_int session_id2_len;
0fff78ff	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	{
	75	debug("%s", ssh_gssapi_last_error(ctxt, NULL, NULL));
	76	}
	77
	78	char *
665a873d	79	ssh_gssapi_last_error(Gssctxt ctxt, OM_uint32 major_status,
665a873d	80	OM_uint32 *minor_status)
0fff78ff	81	{
	82	OM_uint32 lmin;
	83	gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
	84	OM_uint32 ctx;
	85	Buffer b;
	86	char *ret;
	87
	88	buffer_init(&b);
	89
	90	if (major_status != NULL)
	91	*major_status = ctxt->major;
	92	if (minor_status != NULL)
	93	*minor_status = ctxt->minor;
	94
	95	ctx = 0;
	96	/* The GSSAPI error */
	97	do {
	98	gss_display_status(&lmin, ctxt->major,
	99	GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
	100
	101	buffer_append(&b, msg.value, msg.length);
	102	buffer_put_char(&b, '\n');
	103
	104	gss_release_buffer(&lmin, &msg);
	105	} while (ctx != 0);
	106
	107	/* The mechanism specific error */
	108	do {
	109	gss_display_status(&lmin, ctxt->minor,
	110	GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
	111
	112	buffer_append(&b, msg.value, msg.length);
	113	buffer_put_char(&b, '\n');
	114
	115	gss_release_buffer(&lmin, &msg);
	116	} while (ctx != 0);
	117
	118	buffer_put_char(&b, '\0');
	119	ret = xmalloc(buffer_len(&b));
	120	buffer_get(&b, ret, buffer_len(&b));
	121	buffer_free(&b);
	122	return (ret);
	123	}
	124
	125	/*
	126	* Initialise our GSSAPI context. We use this opaque structure to contain all
	127	* of the data which both the client and server need to persist across
	128	* {accept,init}_sec_context calls, so that when we do it from the userauth
	129	* stuff life is a little easier
	130	*/
	131	void
	132	ssh_gssapi_build_ctx(Gssctxt **ctx)
	133	{
	134	*ctx = xmalloc(sizeof (Gssctxt));
	135	(*ctx)->major = 0;
	136	(*ctx)->minor = 0;
	137	(*ctx)->context = GSS_C_NO_CONTEXT;
	138	(*ctx)->name = GSS_C_NO_NAME;
	139	(*ctx)->oid = GSS_C_NO_OID;
	140	(*ctx)->creds = GSS_C_NO_CREDENTIAL;
	141	(*ctx)->client = GSS_C_NO_NAME;
	142	(*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
	143	}
	144
145	/* Delete our context, providing it has been built correctly */
146	void
147	ssh_gssapi_delete_ctx(Gssctxt **ctx)
148	{
149	OM_uint32 ms;
150
151	if ((*ctx) == NULL)
152	return;
153	if ((*ctx)->context != GSS_C_NO_CONTEXT)
154	gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
155	if ((*ctx)->name != GSS_C_NO_NAME)
156	gss_release_name(&ms, &(*ctx)->name);
157	if ((*ctx)->oid != GSS_C_NO_OID) {
158	xfree((*ctx)->oid->elements);
159	xfree((*ctx)->oid);
160	(*ctx)->oid = GSS_C_NO_OID;
161	}
162	if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
163	gss_release_cred(&ms, &(*ctx)->creds);
164	if ((*ctx)->client != GSS_C_NO_NAME)
165	gss_release_name(&ms, &(*ctx)->client);
166	if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
167	gss_release_cred(&ms, &(*ctx)->client_creds);
168
169	xfree(*ctx);
170	*ctx = NULL;
171	}
172
173	/*
174	* Wrapper to init_sec_context
175	* Requires that the context contains:
176	* oid
177	* server name (from ssh_gssapi_import_name)
178	*/
179	OM_uint32
180	ssh_gssapi_init_ctx(Gssctxt ctx, int deleg_creds, gss_buffer_desc recv_tok,
181	gss_buffer_desc* send_tok, OM_uint32 *flags)
182	{
183	int deleg_flag = 0;
184
185	if (deleg_creds) {
186	deleg_flag = GSS_C_DELEG_FLAG;
187	debug("Delegating credentials");
188	}
189
190	ctx->major = gss_init_sec_context(&ctx->minor,
191	GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
192	GSS_C_MUTUAL_FLAG \| GSS_C_INTEG_FLAG \| deleg_flag,
193	0, NULL, recv_tok, NULL, send_tok, flags, NULL);
194
195	if (GSS_ERROR(ctx->major))
196	ssh_gssapi_error(ctx);
197
198	return (ctx->major);
199	}
200
201	/* Create a service name for the given host */
202	OM_uint32
203	ssh_gssapi_import_name(Gssctxt ctx, const char host)
204	{
205	gss_buffer_desc gssbuf;
206
207	gssbuf.length = sizeof("host@") + strlen(host);
208	gssbuf.value = xmalloc(gssbuf.length);
209	snprintf(gssbuf.value, gssbuf.length, "host@%s", host);
210
211	if ((ctx->major = gss_import_name(&ctx->minor,
212	&gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
213	ssh_gssapi_error(ctx);
214
215	xfree(gssbuf.value);
216	return (ctx->major);
217	}
218
219	/* Acquire credentials for a server running on the current host.
220	* Requires that the context structure contains a valid OID
221	*/
222
223	/* Returns a GSSAPI error code */
224	OM_uint32
225	ssh_gssapi_acquire_cred(Gssctxt *ctx)
226	{
227	OM_uint32 status;
228	char lname[MAXHOSTNAMELEN];
229	gss_OID_set oidset;
230
231	gss_create_empty_oid_set(&status, &oidset);
232	gss_add_oid_set_member(&status, ctx->oid, &oidset);
233
234	if (gethostname(lname, MAXHOSTNAMELEN))
235	return (-1);
236
237	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname)))
238	return (ctx->major);
239
240	if ((ctx->major = gss_acquire_cred(&ctx->minor,
241	ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
242	ssh_gssapi_error(ctx);
243
244	gss_release_oid_set(&status, &oidset);
245	return (ctx->major);
246	}
247
cdd66111	248	OM_uint32
	249	ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
	250	{
	251	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
	252	GSS_C_QOP_DEFAULT, buffer, hash)))
	253	ssh_gssapi_error(ctx);
	254
	255	return (ctx->major);
	256	}
	257
	258	void
	259	ssh_gssapi_buildmic(Buffer b, const char user, const char *service,
	260	const char *context)
	261	{
	262	buffer_init(b);
	263	buffer_put_string(b, session_id2, session_id2_len);
	264	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
	265	buffer_put_cstring(b, user);
	266	buffer_put_cstring(b, service);
	267	buffer_put_cstring(b, context);
	268	}
	269
0fff78ff	270	OM_uint32
2c06c99b	271	ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
2c06c99b	272	{
0fff78ff	273	if (*ctx)
	274	ssh_gssapi_delete_ctx(ctx);
	275	ssh_gssapi_build_ctx(ctx);
	276	ssh_gssapi_set_oid(*ctx, oid);
	277	return (ssh_gssapi_acquire_cred(*ctx));
	278	}
	279
	280	#endif /* GSSAPI */