gss_mech_switch.c

  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(pf->domain);
 41		kfree(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(new, prefix);
 55		strcat(new, 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(pf->name);
 70		status = -ENOMEM;
 71		if (pf->auth_domain_name == NULL)
 72			goto out;
 73		dom = svcauth_gss_register_pseudoflavor(
 74			pf->pseudoflavor, pf->auth_domain_name);
 75		if (IS_ERR(dom)) {
 76			status = PTR_ERR(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(&registered_mechs_lock);
101	list_add_rcu(&gm->gm_list, &registered_mechs);
102	spin_unlock(&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(&registered_mechs_lock);
116	list_del_rcu(&gm->gm_list);
117	spin_unlock(&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(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(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(obj->data, pos->gm_oid.data, obj->len)) {
173				if (try_module_get(pos->gm_owner))
174					gm = pos;
175				break;
176			}
177		}
178	}
179	rcu_read_unlock();
180	if (!gm)
181		trace_rpcgss_oid_to_mech(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(pos, pseudoflavor))
204			continue;
205		if (try_module_get(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(&info->oid);
262	if (gm == NULL)
263		return RPC_AUTH_MAXFLAVOR;
264
265	pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, 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(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(*context_handle);
445	*context_handle=NULL;
446	return GSS_S_COMPLETE;
447}