xref: /freebsd/sys/kgssapi/gss_impl.c (revision a25896ca1270e25b657ceaa8d47d5699515f5c25)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
5  * Authors: Doug Rabson <dfr@rabson.org>
6  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/kernel.h>
35 #include <sys/kobj.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/mutex.h>
40 #include <sys/priv.h>
41 #include <sys/syscall.h>
42 #include <sys/sysent.h>
43 #include <sys/sysproto.h>
44 
45 #include <kgssapi/gssapi.h>
46 #include <kgssapi/gssapi_impl.h>
47 #include <rpc/rpc.h>
48 #include <rpc/rpc_com.h>
49 #include <rpc/rpcsec_gss.h>
50 
51 #include "gssd.h"
52 #include "kgss_if.h"
53 
54 MALLOC_DEFINE(M_GSSAPI, "GSS-API", "GSS-API");
55 
56 /*
57  * Syscall hooks
58  */
59 static struct syscall_helper_data gssd_syscalls[] = {
60 	SYSCALL_INIT_HELPER(gssd_syscall),
61 	SYSCALL_INIT_LAST
62 };
63 
64 struct kgss_mech_list kgss_mechs;
65 CLIENT *kgss_gssd_handle;
66 struct mtx kgss_gssd_lock;
67 
68 static int
69 kgss_load(void)
70 {
71 	int error;
72 
73 	LIST_INIT(&kgss_mechs);
74 	error = syscall_helper_register(gssd_syscalls, SY_THR_STATIC_KLD);
75 	if (error != 0)
76 		return (error);
77 	return (0);
78 }
79 
80 static void
81 kgss_unload(void)
82 {
83 
84 	syscall_helper_unregister(gssd_syscalls);
85 }
86 
87 int
88 sys_gssd_syscall(struct thread *td, struct gssd_syscall_args *uap)
89 {
90         struct sockaddr_un sun;
91         struct netconfig *nconf;
92 	char path[MAXPATHLEN];
93 	int error;
94 	CLIENT *cl, *oldcl;
95 
96 	error = priv_check(td, PRIV_NFS_DAEMON);
97 	if (error)
98 		return (error);
99 
100 	error = copyinstr(uap->path, path, sizeof(path), NULL);
101 	if (error)
102 		return (error);
103 	if (strlen(path) + 1 > sizeof(sun.sun_path))
104 		return (EINVAL);
105 
106 	if (path[0] != '\0') {
107 		sun.sun_family = AF_LOCAL;
108 		strlcpy(sun.sun_path, path, sizeof(sun.sun_path));
109 		sun.sun_len = SUN_LEN(&sun);
110 
111 		nconf = getnetconfigent("local");
112 		cl = clnt_reconnect_create(nconf,
113 		    (struct sockaddr *) &sun, GSSD, GSSDVERS,
114 		    RPC_MAXDATASIZE, RPC_MAXDATASIZE);
115 	} else
116 		cl = NULL;
117 
118 	mtx_lock(&kgss_gssd_lock);
119 	oldcl = kgss_gssd_handle;
120 	kgss_gssd_handle = cl;
121 	mtx_unlock(&kgss_gssd_lock);
122 
123 	if (oldcl != NULL) {
124 		CLNT_CLOSE(oldcl);
125 		CLNT_RELEASE(oldcl);
126 	}
127 
128 	return (0);
129 }
130 
131 int
132 kgss_oid_equal(const gss_OID oid1, const gss_OID oid2)
133 {
134 
135 	if (oid1 == oid2)
136 		return (1);
137 	if (!oid1 || !oid2)
138 		return (0);
139 	if (oid1->length != oid2->length)
140 		return (0);
141 	if (memcmp(oid1->elements, oid2->elements, oid1->length))
142 		return (0);
143 	return (1);
144 }
145 
146 void
147 kgss_install_mech(gss_OID mech_type, const char *name, struct kobj_class *cls)
148 {
149 	struct kgss_mech *km;
150 
151 	km = malloc(sizeof(struct kgss_mech), M_GSSAPI, M_WAITOK);
152 	km->km_mech_type = mech_type;
153 	km->km_mech_name = name;
154 	km->km_class = cls;
155 	LIST_INSERT_HEAD(&kgss_mechs, km, km_link);
156 }
157 
158 void
159 kgss_uninstall_mech(gss_OID mech_type)
160 {
161 	struct kgss_mech *km;
162 
163 	LIST_FOREACH(km, &kgss_mechs, km_link) {
164 		if (kgss_oid_equal(km->km_mech_type, mech_type)) {
165 			LIST_REMOVE(km, km_link);
166 			free(km, M_GSSAPI);
167 			return;
168 		}
169 	}
170 }
171 
172 gss_OID
173 kgss_find_mech_by_name(const char *name)
174 {
175 	struct kgss_mech *km;
176 
177 	LIST_FOREACH(km, &kgss_mechs, km_link) {
178 		if (!strcmp(km->km_mech_name, name)) {
179 			return (km->km_mech_type);
180 		}
181 	}
182 	return (GSS_C_NO_OID);
183 }
184 
185 const char *
186 kgss_find_mech_by_oid(const gss_OID oid)
187 {
188 	struct kgss_mech *km;
189 
190 	LIST_FOREACH(km, &kgss_mechs, km_link) {
191 		if (kgss_oid_equal(km->km_mech_type, oid)) {
192 			return (km->km_mech_name);
193 		}
194 	}
195 	return (NULL);
196 }
197 
198 gss_ctx_id_t
199 kgss_create_context(gss_OID mech_type)
200 {
201 	struct kgss_mech *km;
202 	gss_ctx_id_t ctx;
203 
204 	LIST_FOREACH(km, &kgss_mechs, km_link) {
205 		if (kgss_oid_equal(km->km_mech_type, mech_type))
206 			break;
207 	}
208 	if (!km)
209 		return (NULL);
210 
211 	ctx = (gss_ctx_id_t) kobj_create(km->km_class, M_GSSAPI, M_WAITOK);
212 	KGSS_INIT(ctx);
213 
214 	return (ctx);
215 }
216 
217 void
218 kgss_delete_context(gss_ctx_id_t ctx, gss_buffer_t output_token)
219 {
220 
221 	KGSS_DELETE(ctx, output_token);
222 	kobj_delete((kobj_t) ctx, M_GSSAPI);
223 }
224 
225 OM_uint32
226 kgss_transfer_context(gss_ctx_id_t ctx)
227 {
228 	struct export_sec_context_res res;
229 	struct export_sec_context_args args;
230 	enum clnt_stat stat;
231 	OM_uint32 maj_stat;
232 
233 	if (!kgss_gssd_handle)
234 		return (GSS_S_FAILURE);
235 
236 	args.ctx = ctx->handle;
237 	bzero(&res, sizeof(res));
238 	stat = gssd_export_sec_context_1(&args, &res, kgss_gssd_handle);
239 	if (stat != RPC_SUCCESS) {
240 		return (GSS_S_FAILURE);
241 	}
242 
243 	maj_stat = KGSS_IMPORT(ctx, res.format, &res.interprocess_token);
244 	ctx->handle = 0;
245 
246 	xdr_free((xdrproc_t) xdr_export_sec_context_res, &res);
247 
248 	return (maj_stat);
249 }
250 
251 void
252 kgss_copy_buffer(const gss_buffer_t from, gss_buffer_t to)
253 {
254 	to->length = from->length;
255 	if (from->length) {
256 		to->value = malloc(from->length, M_GSSAPI, M_WAITOK);
257 		bcopy(from->value, to->value, from->length);
258 	} else {
259 		to->value = NULL;
260 	}
261 }
262 
263 /*
264  * Acquire the kgss_gssd_handle and return it with a reference count,
265  * if it is available.
266  */
267 CLIENT *
268 kgss_gssd_client(void)
269 {
270 	CLIENT *cl;
271 
272 	mtx_lock(&kgss_gssd_lock);
273 	cl = kgss_gssd_handle;
274 	if (cl != NULL)
275 		CLNT_ACQUIRE(cl);
276 	mtx_unlock(&kgss_gssd_lock);
277 	return (cl);
278 }
279 
280 /*
281  * Kernel module glue
282  */
283 static int
284 kgssapi_modevent(module_t mod, int type, void *data)
285 {
286 	int error = 0;
287 
288 	switch (type) {
289 	case MOD_LOAD:
290 		rpc_gss_entries.rpc_gss_refresh_auth = rpc_gss_refresh_auth;
291 		rpc_gss_entries.rpc_gss_secfind = rpc_gss_secfind;
292 		rpc_gss_entries.rpc_gss_secpurge = rpc_gss_secpurge;
293 		rpc_gss_entries.rpc_gss_seccreate = rpc_gss_seccreate;
294 		rpc_gss_entries.rpc_gss_set_defaults = rpc_gss_set_defaults;
295 		rpc_gss_entries.rpc_gss_max_data_length =
296 		    rpc_gss_max_data_length;
297 		rpc_gss_entries.rpc_gss_get_error = rpc_gss_get_error;
298 		rpc_gss_entries.rpc_gss_mech_to_oid = rpc_gss_mech_to_oid;
299 		rpc_gss_entries.rpc_gss_oid_to_mech = rpc_gss_oid_to_mech;
300 		rpc_gss_entries.rpc_gss_qop_to_num = rpc_gss_qop_to_num;
301 		rpc_gss_entries.rpc_gss_get_mechanisms = rpc_gss_get_mechanisms;
302 		rpc_gss_entries.rpc_gss_get_versions = rpc_gss_get_versions;
303 		rpc_gss_entries.rpc_gss_is_installed = rpc_gss_is_installed;
304 		rpc_gss_entries.rpc_gss_set_svc_name = rpc_gss_set_svc_name;
305 		rpc_gss_entries.rpc_gss_clear_svc_name = rpc_gss_clear_svc_name;
306 		rpc_gss_entries.rpc_gss_getcred = rpc_gss_getcred;
307 		rpc_gss_entries.rpc_gss_set_callback = rpc_gss_set_callback;
308 		rpc_gss_entries.rpc_gss_clear_callback = rpc_gss_clear_callback;
309 		rpc_gss_entries.rpc_gss_get_principal_name =
310 		    rpc_gss_get_principal_name;
311 		rpc_gss_entries.rpc_gss_svc_max_data_length =
312 		    rpc_gss_svc_max_data_length;
313 		mtx_init(&kgss_gssd_lock, "kgss_gssd_lock", NULL, MTX_DEF);
314 		error = kgss_load();
315 		break;
316 	case MOD_UNLOAD:
317 		kgss_unload();
318 		mtx_destroy(&kgss_gssd_lock);
319 		/*
320 		 * Unloading of the kgssapi module is not currently supported.
321 		 * If somebody wants this, we would need to keep track of
322 		 * currently executing threads and make sure the count is 0.
323 		 */
324 		/* FALLTHROUGH */
325 	default:
326 		error = EOPNOTSUPP;
327 	}
328 	return (error);
329 }
330 static moduledata_t kgssapi_mod = {
331 	"kgssapi",
332 	kgssapi_modevent,
333 	NULL,
334 };
335 DECLARE_MODULE(kgssapi, kgssapi_mod, SI_SUB_VFS, SI_ORDER_ANY);
336 MODULE_DEPEND(kgssapi, krpc, 1, 1, 1);
337 MODULE_VERSION(kgssapi, 1);
338