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

source code of linux/net/sunrpc/auth_gss/gss_mech_switch.c