1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3 * linux/net/sunrpc/gss_mech_switch.c
4 *
5 * Copyright (c) 2001 The Regents of the University of Michigan.
6 * All rights reserved.
7 *
8 * J. Bruce Fields <bfields@umich.edu>
9 */
10
11 #include <linux/types.h>
12 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/oid_registry.h>
15 #include <linux/sunrpc/msg_prot.h>
16 #include <linux/sunrpc/gss_asn1.h>
17 #include <linux/sunrpc/auth_gss.h>
18 #include <linux/sunrpc/svcauth_gss.h>
19 #include <linux/sunrpc/gss_err.h>
20 #include <linux/sunrpc/sched.h>
21 #include <linux/sunrpc/gss_api.h>
22 #include <linux/sunrpc/clnt.h>
23 #include <trace/events/rpcgss.h>
24
25 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
26 # define RPCDBG_FACILITY RPCDBG_AUTH
27 #endif
28
29 static LIST_HEAD(registered_mechs);
30 static DEFINE_SPINLOCK(registered_mechs_lock);
31
32 static void
33 gss_mech_free(struct gss_api_mech *gm)
34 {
35 struct pf_desc *pf;
36 int i;
37
38 for (i = 0; i < gm->gm_pf_num; i++) {
39 pf = &gm->gm_pfs[i];
40 if (pf->domain)
41 auth_domain_put(pf->domain);
42 kfree(pf->auth_domain_name);
43 pf->auth_domain_name = NULL;
44 }
45 }
46
47 static inline char *
48 make_auth_domain_name(char *name)
49 {
50 static char *prefix = "gss/";
51 char *new;
52
53 new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
54 if (new) {
55 strcpy(new, prefix);
56 strcat(new, name);
57 }
58 return new;
59 }
60
61 static int
62 gss_mech_svc_setup(struct gss_api_mech *gm)
63 {
64 struct auth_domain *dom;
65 struct pf_desc *pf;
66 int i, status;
67
68 for (i = 0; i < gm->gm_pf_num; i++) {
69 pf = &gm->gm_pfs[i];
70 pf->auth_domain_name = make_auth_domain_name(pf->name);
71 status = -ENOMEM;
72 if (pf->auth_domain_name == NULL)
73 goto out;
74 dom = svcauth_gss_register_pseudoflavor(
75 pf->pseudoflavor, pf->auth_domain_name);
76 if (IS_ERR(dom)) {
77 status = PTR_ERR(dom);
78 goto out;
79 }
80 pf->domain = dom;
81 }
82 return 0;
83 out:
84 gss_mech_free(gm);
85 return status;
86 }
87
88 /**
89 * gss_mech_register - register a GSS mechanism
90 * @gm: GSS mechanism handle
91 *
92 * Returns zero if successful, or a negative errno.
93 */
94 int gss_mech_register(struct gss_api_mech *gm)
95 {
96 int status;
97
98 status = gss_mech_svc_setup(gm);
99 if (status)
100 return status;
101 spin_lock(®istered_mechs_lock);
102 list_add_rcu(&gm->gm_list, ®istered_mechs);
103 spin_unlock(®istered_mechs_lock);
104 dprintk("RPC: registered gss mechanism %s\n", gm->gm_name);
105 return 0;
106 }
107 EXPORT_SYMBOL_GPL(gss_mech_register);
108
109 /**
110 * gss_mech_unregister - release a GSS mechanism
111 * @gm: GSS mechanism handle
112 *
113 */
114 void gss_mech_unregister(struct gss_api_mech *gm)
115 {
116 spin_lock(®istered_mechs_lock);
117 list_del_rcu(&gm->gm_list);
118 spin_unlock(®istered_mechs_lock);
119 dprintk("RPC: unregistered gss mechanism %s\n", gm->gm_name);
120 gss_mech_free(gm);
121 }
122 EXPORT_SYMBOL_GPL(gss_mech_unregister);
123
124 struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
125 {
126 __module_get(gm->gm_owner);
127 return gm;
128 }
129 EXPORT_SYMBOL(gss_mech_get);
130
131 static struct gss_api_mech *
132 _gss_mech_get_by_name(const char *name)
133 {
134 struct gss_api_mech *pos, *gm = NULL;
135
136 rcu_read_lock();
137 list_for_each_entry_rcu(pos, ®istered_mechs, gm_list) {
138 if (0 == strcmp(name, pos->gm_name)) {
139 if (try_module_get(pos->gm_owner))
140 gm = pos;
141 break;
142 }
143 }
144 rcu_read_unlock();
145 return gm;
146
147 }
148
149 struct gss_api_mech * gss_mech_get_by_name(const char *name)
150 {
151 struct gss_api_mech *gm = NULL;
152
153 gm = _gss_mech_get_by_name(name);
154 if (!gm) {
155 request_module("rpc-auth-gss-%s", name);
156 gm = _gss_mech_get_by_name(name);
157 }
158 return gm;
159 }
160
161 struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
162 {
163 struct gss_api_mech *pos, *gm = NULL;
164 char buf[32];
165
166 if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
167 return NULL;
168 request_module("rpc-auth-gss-%s", buf);
169
170 rcu_read_lock();
171 list_for_each_entry_rcu(pos, ®istered_mechs, gm_list) {
172 if (obj->len == pos->gm_oid.len) {
173 if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
174 if (try_module_get(pos->gm_owner))
175 gm = pos;
176 break;
177 }
178 }
179 }
180 rcu_read_unlock();
181 if (!gm)
182 trace_rpcgss_oid_to_mech(buf);
183 return gm;
184 }
185
186 static inline int
187 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
188 {
189 int i;
190
191 for (i = 0; i < gm->gm_pf_num; i++) {
192 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
193 return 1;
194 }
195 return 0;
196 }
197
198 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
199 {
200 struct gss_api_mech *gm = NULL, *pos;
201
202 rcu_read_lock();
203 list_for_each_entry_rcu(pos, ®istered_mechs, gm_list) {
204 if (!mech_supports_pseudoflavor(pos, pseudoflavor))
205 continue;
206 if (try_module_get(pos->gm_owner))
207 gm = pos;
208 break;
209 }
210 rcu_read_unlock();
211 return gm;
212 }
213
214 struct gss_api_mech *
215 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
216 {
217 struct gss_api_mech *gm;
218
219 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
220
221 if (!gm) {
222 request_module("rpc-auth-gss-%u", pseudoflavor);
223 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
224 }
225 return gm;
226 }
227
228 /**
229 * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
230 * @gm: GSS mechanism handle
231 * @qop: GSS quality-of-protection value
232 * @service: GSS service value
233 *
234 * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
235 */
236 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
237 u32 service)
238 {
239 int i;
240
241 for (i = 0; i < gm->gm_pf_num; i++) {
242 if (gm->gm_pfs[i].qop == qop &&
243 gm->gm_pfs[i].service == service) {
244 return gm->gm_pfs[i].pseudoflavor;
245 }
246 }
247 return RPC_AUTH_MAXFLAVOR;
248 }
249
250 /**
251 * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
252 * @info: a GSS mech OID, quality of protection, and service value
253 *
254 * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
255 * not supported.
256 */
257 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
258 {
259 rpc_authflavor_t pseudoflavor;
260 struct gss_api_mech *gm;
261
262 gm = gss_mech_get_by_OID(&info->oid);
263 if (gm == NULL)
264 return RPC_AUTH_MAXFLAVOR;
265
266 pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
267
268 gss_mech_put(gm);
269 return pseudoflavor;
270 }
271
272 /**
273 * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
274 * @pseudoflavor: GSS pseudoflavor to match
275 * @info: rpcsec_gss_info structure to fill in
276 *
277 * Returns zero and fills in "info" if pseudoflavor matches a
278 * supported mechanism. Otherwise a negative errno is returned.
279 */
280 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
281 struct rpcsec_gss_info *info)
282 {
283 struct gss_api_mech *gm;
284 int i;
285
286 gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
287 if (gm == NULL)
288 return -ENOENT;
289
290 for (i = 0; i < gm->gm_pf_num; i++) {
291 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
292 memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
293 info->oid.len = gm->gm_oid.len;
294 info->qop = gm->gm_pfs[i].qop;
295 info->service = gm->gm_pfs[i].service;
296 gss_mech_put(gm);
297 return 0;
298 }
299 }
300
301 gss_mech_put(gm);
302 return -ENOENT;
303 }
304
305 u32
306 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
307 {
308 int i;
309
310 for (i = 0; i < gm->gm_pf_num; i++) {
311 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
312 return gm->gm_pfs[i].service;
313 }
314 return 0;
315 }
316 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
317
318 bool
319 gss_pseudoflavor_to_datatouch(struct gss_api_mech *gm, u32 pseudoflavor)
320 {
321 int i;
322
323 for (i = 0; i < gm->gm_pf_num; i++) {
324 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
325 return gm->gm_pfs[i].datatouch;
326 }
327 return false;
328 }
329
330 char *
331 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
332 {
333 int i;
334
335 for (i = 0; i < gm->gm_pf_num; i++) {
336 if (gm->gm_pfs[i].service == service)
337 return gm->gm_pfs[i].auth_domain_name;
338 }
339 return NULL;
340 }
341
342 void
343 gss_mech_put(struct gss_api_mech * gm)
344 {
345 if (gm)
346 module_put(gm->gm_owner);
347 }
348 EXPORT_SYMBOL(gss_mech_put);
349
350 /* The mech could probably be determined from the token instead, but it's just
351 * as easy for now to pass it in. */
352 int
353 gss_import_sec_context(const void *input_token, size_t bufsize,
354 struct gss_api_mech *mech,
355 struct gss_ctx **ctx_id,
356 time64_t *endtime,
357 gfp_t gfp_mask)
358 {
359 if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
360 return -ENOMEM;
361 (*ctx_id)->mech_type = gss_mech_get(mech);
362
363 return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
364 *ctx_id, endtime, gfp_mask);
365 }
366
367 /* gss_get_mic: compute a mic over message and return mic_token. */
368
369 u32
370 gss_get_mic(struct gss_ctx *context_handle,
371 struct xdr_buf *message,
372 struct xdr_netobj *mic_token)
373 {
374 return context_handle->mech_type->gm_ops
375 ->gss_get_mic(context_handle,
376 message,
377 mic_token);
378 }
379
380 /* gss_verify_mic: check whether the provided mic_token verifies message. */
381
382 u32
383 gss_verify_mic(struct gss_ctx *context_handle,
384 struct xdr_buf *message,
385 struct xdr_netobj *mic_token)
386 {
387 return context_handle->mech_type->gm_ops
388 ->gss_verify_mic(context_handle,
389 message,
390 mic_token);
391 }
392
393 /*
394 * This function is called from both the client and server code.
395 * Each makes guarantees about how much "slack" space is available
396 * for the underlying function in "buf"'s head and tail while
397 * performing the wrap.
398 *
399 * The client and server code allocate RPC_MAX_AUTH_SIZE extra
400 * space in both the head and tail which is available for use by
401 * the wrap function.
402 *
403 * Underlying functions should verify they do not use more than
404 * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
405 * when performing the wrap.
406 */
407 u32
408 gss_wrap(struct gss_ctx *ctx_id,
409 int offset,
410 struct xdr_buf *buf,
411 struct page **inpages)
412 {
413 return ctx_id->mech_type->gm_ops
414 ->gss_wrap(ctx_id, offset, buf, inpages);
415 }
416
417 u32
418 gss_unwrap(struct gss_ctx *ctx_id,
419 int offset,
420 int len,
421 struct xdr_buf *buf)
422 {
423 return ctx_id->mech_type->gm_ops
424 ->gss_unwrap(ctx_id, offset, len, buf);
425 }
426
427
428 /* gss_delete_sec_context: free all resources associated with context_handle.
429 * Note this differs from the RFC 2744-specified prototype in that we don't
430 * bother returning an output token, since it would never be used anyway. */
431
432 u32
433 gss_delete_sec_context(struct gss_ctx **context_handle)
434 {
435 dprintk("RPC: gss_delete_sec_context deleting %p\n",
436 *context_handle);
437
438 if (!*context_handle)
439 return GSS_S_NO_CONTEXT;
440 if ((*context_handle)->internal_ctx_id)
441 (*context_handle)->mech_type->gm_ops
442 ->gss_delete_sec_context((*context_handle)
443 ->internal_ctx_id);
444 gss_mech_put((*context_handle)->mech_type);
445 kfree(*context_handle);
446 *context_handle=NULL;
447 return GSS_S_COMPLETE;
448 }
449
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