net/sunrpc/auth_gss/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/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(&registered_mechs_lock);
 102         list_add_rcu(&gm->gm_list, &registered_mechs);
 103         spin_unlock(&registered_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(&registered_mechs_lock);
 117         list_del_rcu(&gm->gm_list);
 118         spin_unlock(&registered_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, &registered_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, &registered_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, &registered_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 }