[openssh.git] / gss-genr.c

/* $OpenBSD: gss-genr.c,v 1.11 2006/07/22 20:48:23 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 <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
00146caa	1	/* $OpenBSD: gss-genr.c,v 1.11 2006/07/22 20:48:23 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
00146caa	31	#include <string.h>
28cb0a43	32	#include <unistd.h>
00146caa	33
7364bd04	34	#include "xmalloc.h"
7364bd04	35	#include "bufaux.h"
7364bd04	36	#include "log.h"
0789992b	37	#include "ssh2.h"
7364bd04	38
	39	#include "ssh-gss.h"
	40
0789992b	41	extern u_char *session_id2;
0789992b	42	extern u_int session_id2_len;
7364bd04	43
	44	/* Check that the OID in a data stream matches that in the context */
	45	int
	46	ssh_gssapi_check_oid(Gssctxt ctx, void data, size_t len)
	47	{
	48	return (ctx != NULL && ctx->oid != GSS_C_NO_OID &&
	49	ctx->oid->length == len &&
	50	memcmp(ctx->oid->elements, data, len) == 0);
	51	}
	52
	53	/* Set the contexts OID from a data stream */
	54	void
	55	ssh_gssapi_set_oid_data(Gssctxt ctx, void data, size_t len)
	56	{
	57	if (ctx->oid != GSS_C_NO_OID) {
	58	xfree(ctx->oid->elements);
	59	xfree(ctx->oid);
	60	}
	61	ctx->oid = xmalloc(sizeof(gss_OID_desc));
	62	ctx->oid->length = len;
	63	ctx->oid->elements = xmalloc(len);
	64	memcpy(ctx->oid->elements, data, len);
	65	}
	66
	67	/* Set the contexts OID */
	68	void
	69	ssh_gssapi_set_oid(Gssctxt *ctx, gss_OID oid)
	70	{
	71	ssh_gssapi_set_oid_data(ctx, oid->elements, oid->length);
	72	}
	73
	74	/* All this effort to report an error ... */
	75	void
	76	ssh_gssapi_error(Gssctxt *ctxt)
	77	{
0926fd19	78	char *s;
	79
	80	s = ssh_gssapi_last_error(ctxt, NULL, NULL);
	81	debug("%s", s);
	82	xfree(s);
7364bd04	83	}
	84
	85	char *
4e2e5cfd	86	ssh_gssapi_last_error(Gssctxt ctxt, OM_uint32 major_status,
4e2e5cfd	87	OM_uint32 *minor_status)
7364bd04	88	{
	89	OM_uint32 lmin;
	90	gss_buffer_desc msg = GSS_C_EMPTY_BUFFER;
	91	OM_uint32 ctx;
	92	Buffer b;
	93	char *ret;
	94
	95	buffer_init(&b);
	96
	97	if (major_status != NULL)
	98	*major_status = ctxt->major;
	99	if (minor_status != NULL)
	100	*minor_status = ctxt->minor;
	101
	102	ctx = 0;
	103	/* The GSSAPI error */
	104	do {
	105	gss_display_status(&lmin, ctxt->major,
	106	GSS_C_GSS_CODE, GSS_C_NULL_OID, &ctx, &msg);
	107
	108	buffer_append(&b, msg.value, msg.length);
	109	buffer_put_char(&b, '\n');
	110
	111	gss_release_buffer(&lmin, &msg);
	112	} while (ctx != 0);
	113
	114	/* The mechanism specific error */
	115	do {
	116	gss_display_status(&lmin, ctxt->minor,
	117	GSS_C_MECH_CODE, GSS_C_NULL_OID, &ctx, &msg);
	118
	119	buffer_append(&b, msg.value, msg.length);
	120	buffer_put_char(&b, '\n');
	121
	122	gss_release_buffer(&lmin, &msg);
	123	} while (ctx != 0);
	124
	125	buffer_put_char(&b, '\0');
	126	ret = xmalloc(buffer_len(&b));
	127	buffer_get(&b, ret, buffer_len(&b));
	128	buffer_free(&b);
	129	return (ret);
	130	}
	131
	132	/*
	133	* Initialise our GSSAPI context. We use this opaque structure to contain all
	134	* of the data which both the client and server need to persist across
	135	* {accept,init}_sec_context calls, so that when we do it from the userauth
	136	* stuff life is a little easier
	137	*/
	138	void
	139	ssh_gssapi_build_ctx(Gssctxt **ctx)
	140	{
52e3daed	141	*ctx = xcalloc(1, sizeof (Gssctxt));
7364bd04	142	(*ctx)->context = GSS_C_NO_CONTEXT;
	143	(*ctx)->name = GSS_C_NO_NAME;
	144	(*ctx)->oid = GSS_C_NO_OID;
	145	(*ctx)->creds = GSS_C_NO_CREDENTIAL;
	146	(*ctx)->client = GSS_C_NO_NAME;
	147	(*ctx)->client_creds = GSS_C_NO_CREDENTIAL;
	148	}
	149
	150	/* Delete our context, providing it has been built correctly */
	151	void
	152	ssh_gssapi_delete_ctx(Gssctxt **ctx)
	153	{
	154	OM_uint32 ms;
	155
	156	if ((*ctx) == NULL)
	157	return;
	158	if ((*ctx)->context != GSS_C_NO_CONTEXT)
	159	gss_delete_sec_context(&ms, &(*ctx)->context, GSS_C_NO_BUFFER);
	160	if ((*ctx)->name != GSS_C_NO_NAME)
	161	gss_release_name(&ms, &(*ctx)->name);
	162	if ((*ctx)->oid != GSS_C_NO_OID) {
	163	xfree((*ctx)->oid->elements);
	164	xfree((*ctx)->oid);
	165	(*ctx)->oid = GSS_C_NO_OID;
	166	}
	167	if ((*ctx)->creds != GSS_C_NO_CREDENTIAL)
	168	gss_release_cred(&ms, &(*ctx)->creds);
	169	if ((*ctx)->client != GSS_C_NO_NAME)
	170	gss_release_name(&ms, &(*ctx)->client);
	171	if ((*ctx)->client_creds != GSS_C_NO_CREDENTIAL)
	172	gss_release_cred(&ms, &(*ctx)->client_creds);
	173
	174	xfree(*ctx);
	175	*ctx = NULL;
	176	}
	177
	178	/*
	179	* Wrapper to init_sec_context
	180	* Requires that the context contains:
	181	* oid
	182	* server name (from ssh_gssapi_import_name)
	183	*/
	184	OM_uint32
	185	ssh_gssapi_init_ctx(Gssctxt ctx, int deleg_creds, gss_buffer_desc recv_tok,
	186	gss_buffer_desc* send_tok, OM_uint32 *flags)
	187	{
	188	int deleg_flag = 0;
	189
	190	if (deleg_creds) {
	191	deleg_flag = GSS_C_DELEG_FLAG;
	192	debug("Delegating credentials");
	193	}
	194
	195	ctx->major = gss_init_sec_context(&ctx->minor,
	196	GSS_C_NO_CREDENTIAL, &ctx->context, ctx->name, ctx->oid,
	197	GSS_C_MUTUAL_FLAG \| GSS_C_INTEG_FLAG \| deleg_flag,
	198	0, NULL, recv_tok, NULL, send_tok, flags, NULL);
	199
	200	if (GSS_ERROR(ctx->major))
	201	ssh_gssapi_error(ctx);
	202
	203	return (ctx->major);
	204	}
	205
206	/* Create a service name for the given host */
207	OM_uint32
208	ssh_gssapi_import_name(Gssctxt ctx, const char host)
209	{
210	gss_buffer_desc gssbuf;
9c3c8eb1	211	char *val;
7364bd04	212
9c3c8eb1	213	xasprintf(&val, "host@%s", host);
	214	gssbuf.value = val;
	215	gssbuf.length = strlen(gssbuf.value);
7364bd04	216
	217	if ((ctx->major = gss_import_name(&ctx->minor,
	218	&gssbuf, GSS_C_NT_HOSTBASED_SERVICE, &ctx->name)))
	219	ssh_gssapi_error(ctx);
	220
	221	xfree(gssbuf.value);
	222	return (ctx->major);
	223	}
	224
	225	/* Acquire credentials for a server running on the current host.
	226	* Requires that the context structure contains a valid OID
	227	*/
	228
	229	/* Returns a GSSAPI error code */
	230	OM_uint32
	231	ssh_gssapi_acquire_cred(Gssctxt *ctx)
	232	{
	233	OM_uint32 status;
	234	char lname[MAXHOSTNAMELEN];
	235	gss_OID_set oidset;
	236
	237	gss_create_empty_oid_set(&status, &oidset);
	238	gss_add_oid_set_member(&status, ctx->oid, &oidset);
	239
0926fd19	240	if (gethostname(lname, MAXHOSTNAMELEN)) {
0926fd19	241	gss_release_oid_set(&status, &oidset);
7364bd04	242	return (-1);
0926fd19	243	}
7364bd04	244
0926fd19	245	if (GSS_ERROR(ssh_gssapi_import_name(ctx, lname))) {
0926fd19	246	gss_release_oid_set(&status, &oidset);
7364bd04	247	return (ctx->major);
0926fd19	248	}
7364bd04	249
	250	if ((ctx->major = gss_acquire_cred(&ctx->minor,
	251	ctx->name, 0, oidset, GSS_C_ACCEPT, &ctx->creds, NULL, NULL)))
	252	ssh_gssapi_error(ctx);
	253
	254	gss_release_oid_set(&status, &oidset);
	255	return (ctx->major);
	256	}
	257
0789992b	258	OM_uint32
	259	ssh_gssapi_sign(Gssctxt *ctx, gss_buffer_t buffer, gss_buffer_t hash)
	260	{
	261	if ((ctx->major = gss_get_mic(&ctx->minor, ctx->context,
	262	GSS_C_QOP_DEFAULT, buffer, hash)))
	263	ssh_gssapi_error(ctx);
b6453d99	264
0789992b	265	return (ctx->major);
	266	}
	267
	268	void
aff51935	269	ssh_gssapi_buildmic(Buffer b, const char user, const char *service,
aff51935	270	const char *context)
b6453d99	271	{
0789992b	272	buffer_init(b);
	273	buffer_put_string(b, session_id2, session_id2_len);
	274	buffer_put_char(b, SSH2_MSG_USERAUTH_REQUEST);
	275	buffer_put_cstring(b, user);
	276	buffer_put_cstring(b, service);
	277	buffer_put_cstring(b, context);
	278	}
	279
7364bd04	280	OM_uint32
8442cc66	281	ssh_gssapi_server_ctx(Gssctxt **ctx, gss_OID oid)
8442cc66	282	{
7364bd04	283	if (*ctx)
	284	ssh_gssapi_delete_ctx(ctx);
	285	ssh_gssapi_build_ctx(ctx);
	286	ssh_gssapi_set_oid(*ctx, oid);
	287	return (ssh_gssapi_acquire_cred(*ctx));
	288	}
	289
	290	#endif /* GSSAPI */