net/sunrpc/auth_gss/gss_mech_switch.c

   1 /*
   2  *  linux/net/sunrpc/gss_mech_switch.c
   3  *
   4  *  Copyright (c) 2001 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  J. Bruce Fields   <bfields@umich.edu>
   8  *
   9  *  Redistribution and use in source and binary forms, with or without
  10  *  modification, are permitted provided that the following conditions
  11  *  are met:
  12  *
  13  *  1. Redistributions of source code must retain the above copyright
  14  *     notice, this list of conditions and the following disclaimer.
  15  *  2. Redistributions in binary form must reproduce the above copyright
  16  *     notice, this list of conditions and the following disclaimer in the
  17  *     documentation and/or other materials provided with the distribution.
  18  *  3. Neither the name of the University nor the names of its
  19  *     contributors may be used to endorse or promote products derived
  20  *     from this software without specific prior written permission.
  21  *
  22  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  23  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  24  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  29  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  30  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  31  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  32  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  */
  35
  36 #include <linux/types.h>
  37 #include <linux/slab.h>
  38 #include <linux/module.h>
  39 #include <linux/oid_registry.h>
  40 #include <linux/sunrpc/msg_prot.h>
  41 #include <linux/sunrpc/gss_asn1.h>
  42 #include <linux/sunrpc/auth_gss.h>
  43 #include <linux/sunrpc/svcauth_gss.h>
  44 #include <linux/sunrpc/gss_err.h>
  45 #include <linux/sunrpc/sched.h>
  46 #include <linux/sunrpc/gss_api.h>
  47 #include <linux/sunrpc/clnt.h>
  48
  49 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  50 # define RPCDBG_FACILITY        RPCDBG_AUTH
  51 #endif
  52
  53 static LIST_HEAD(registered_mechs);
  54 static DEFINE_SPINLOCK(registered_mechs_lock);
  55
  56 static void
  57 gss_mech_free(struct gss_api_mech *gm)
  58 {
  59         struct pf_desc *pf;
  60         int i;
  61
  62         for (i = 0; i < gm->gm_pf_num; i++) {
  63                 pf = &gm->gm_pfs[i];
  64                 if (pf->domain)
  65                         auth_domain_put(pf->domain);
  66                 kfree(pf->auth_domain_name);
  67                 pf->auth_domain_name = NULL;
  68         }
  69 }
  70
  71 static inline char *
  72 make_auth_domain_name(char *name)
  73 {
  74         static char     *prefix = "gss/";
  75         char            *new;
  76
  77         new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
  78         if (new) {
  79                 strcpy(new, prefix);
  80                 strcat(new, name);
  81         }
  82         return new;
  83 }
  84
  85 static int
  86 gss_mech_svc_setup(struct gss_api_mech *gm)
  87 {
  88         struct auth_domain *dom;
  89         struct pf_desc *pf;
  90         int i, status;
  91
  92         for (i = 0; i < gm->gm_pf_num; i++) {
  93                 pf = &gm->gm_pfs[i];
  94                 pf->auth_domain_name = make_auth_domain_name(pf->name);
  95                 status = -ENOMEM;
  96                 if (pf->auth_domain_name == NULL)
  97                         goto out;
  98                 dom = svcauth_gss_register_pseudoflavor(
  99                         pf->pseudoflavor, pf->auth_domain_name);
 100                 if (IS_ERR(dom)) {
 101                         status = PTR_ERR(dom);
 102                         goto out;
 103                 }
 104                 pf->domain = dom;
 105         }
 106         return 0;
 107 out:
 108         gss_mech_free(gm);
 109         return status;
 110 }
 111
 112 /**
 113  * gss_mech_register - register a GSS mechanism
 114  * @gm: GSS mechanism handle
 115  *
 116  * Returns zero if successful, or a negative errno.
 117  */
 118 int gss_mech_register(struct gss_api_mech *gm)
 119 {
 120         int status;
 121
 122         status = gss_mech_svc_setup(gm);
 123         if (status)
 124                 return status;
 125         spin_lock(&registered_mechs_lock);
 126         list_add(&gm->gm_list, &registered_mechs);
 127         spin_unlock(&registered_mechs_lock);
 128         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
 129         return 0;
 130 }
 131 EXPORT_SYMBOL_GPL(gss_mech_register);
 132
 133 /**
 134  * gss_mech_unregister - release a GSS mechanism
 135  * @gm: GSS mechanism handle
 136  *
 137  */
 138 void gss_mech_unregister(struct gss_api_mech *gm)
 139 {
 140         spin_lock(&registered_mechs_lock);
 141         list_del(&gm->gm_list);
 142         spin_unlock(&registered_mechs_lock);
 143         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 144         gss_mech_free(gm);
 145 }
 146 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 147
 148 struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
 149 {
 150         __module_get(gm->gm_owner);
 151         return gm;
 152 }
 153 EXPORT_SYMBOL(gss_mech_get);
 154
 155 static struct gss_api_mech *
 156 _gss_mech_get_by_name(const char *name)
 157 {
 158         struct gss_api_mech     *pos, *gm = NULL;
 159
 160         spin_lock(&registered_mechs_lock);
 161         list_for_each_entry(pos, &registered_mechs, gm_list) {
 162                 if (0 == strcmp(name, pos->gm_name)) {
 163                         if (try_module_get(pos->gm_owner))
 164                                 gm = pos;
 165                         break;
 166                 }
 167         }
 168         spin_unlock(&registered_mechs_lock);
 169         return gm;
 170
 171 }
 172
 173 struct gss_api_mech * gss_mech_get_by_name(const char *name)
 174 {
 175         struct gss_api_mech *gm = NULL;
 176
 177         gm = _gss_mech_get_by_name(name);
 178         if (!gm) {
 179                 request_module("rpc-auth-gss-%s", name);
 180                 gm = _gss_mech_get_by_name(name);
 181         }
 182         return gm;
 183 }
 184
 185 struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 186 {
 187         struct gss_api_mech     *pos, *gm = NULL;
 188         char buf[32];
 189
 190         if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
 191                 return NULL;
 192         dprintk("RPC:       %s(%s)\n", __func__, buf);
 193         request_module("rpc-auth-gss-%s", buf);
 194
 195         spin_lock(&registered_mechs_lock);
 196         list_for_each_entry(pos, &registered_mechs, gm_list) {
 197                 if (obj->len == pos->gm_oid.len) {
 198                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 199                                 if (try_module_get(pos->gm_owner))
 200                                         gm = pos;
 201                                 break;
 202                         }
 203                 }
 204         }
 205         spin_unlock(&registered_mechs_lock);
 206         return gm;
 207 }
 208
 209 static inline int
 210 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 211 {
 212         int i;
 213
 214         for (i = 0; i < gm->gm_pf_num; i++) {
 215                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 216                         return 1;
 217         }
 218         return 0;
 219 }
 220
 221 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 222 {
 223         struct gss_api_mech *gm = NULL, *pos;
 224
 225         spin_lock(&registered_mechs_lock);
 226         list_for_each_entry(pos, &registered_mechs, gm_list) {
 227                 if (!mech_supports_pseudoflavor(pos, pseudoflavor))
 228                         continue;
 229                 if (try_module_get(pos->gm_owner))
 230                         gm = pos;
 231                 break;
 232         }
 233         spin_unlock(&registered_mechs_lock);
 234         return gm;
 235 }
 236
 237 struct gss_api_mech *
 238 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 239 {
 240         struct gss_api_mech *gm;
 241
 242         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 243
 244         if (!gm) {
 245                 request_module("rpc-auth-gss-%u", pseudoflavor);
 246                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 247         }
 248         return gm;
 249 }
 250
 251 /**
 252  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
 253  * @array: array to fill in
 254  * @size: size of "array"
 255  *
 256  * Returns the number of array items filled in, or a negative errno.
 257  *
 258  * The returned array is not sorted by any policy.  Callers should not
 259  * rely on the order of the items in the returned array.
 260  */
 261 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 262 {
 263         struct gss_api_mech *pos = NULL;
 264         int j, i = 0;
 265
 266         spin_lock(&registered_mechs_lock);
 267         list_for_each_entry(pos, &registered_mechs, gm_list) {
 268                 for (j = 0; j < pos->gm_pf_num; j++) {
 269                         if (i >= size) {
 270                                 spin_unlock(&registered_mechs_lock);
 271                                 return -ENOMEM;
 272                         }
 273                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 274                 }
 275         }
 276         spin_unlock(&registered_mechs_lock);
 277         return i;
 278 }
 279
 280 /**
 281  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
 282  * @gm: GSS mechanism handle
 283  * @qop: GSS quality-of-protection value
 284  * @service: GSS service value
 285  *
 286  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
 287  */
 288 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
 289                                          u32 service)
 290 {
 291         int i;
 292
 293         for (i = 0; i < gm->gm_pf_num; i++) {
 294                 if (gm->gm_pfs[i].qop == qop &&
 295                     gm->gm_pfs[i].service == service) {
 296                         return gm->gm_pfs[i].pseudoflavor;
 297                 }
 298         }
 299         return RPC_AUTH_MAXFLAVOR;
 300 }
 301
 302 /**
 303  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
 304  * @info: a GSS mech OID, quality of protection, and service value
 305  *
 306  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
 307  * not supported.
 308  */
 309 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
 310 {
 311         rpc_authflavor_t pseudoflavor;
 312         struct gss_api_mech *gm;
 313
 314         gm = gss_mech_get_by_OID(&info->oid);
 315         if (gm == NULL)
 316                 return RPC_AUTH_MAXFLAVOR;
 317
 318         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
 319
 320         gss_mech_put(gm);
 321         return pseudoflavor;
 322 }
 323
 324 /**
 325  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
 326  * @pseudoflavor: GSS pseudoflavor to match
 327  * @info: rpcsec_gss_info structure to fill in
 328  *
 329  * Returns zero and fills in "info" if pseudoflavor matches a
 330  * supported mechanism.  Otherwise a negative errno is returned.
 331  */
 332 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
 333                          struct rpcsec_gss_info *info)
 334 {
 335         struct gss_api_mech *gm;
 336         int i;
 337
 338         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
 339         if (gm == NULL)
 340                 return -ENOENT;
 341
 342         for (i = 0; i < gm->gm_pf_num; i++) {
 343                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
 344                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
 345                         info->oid.len = gm->gm_oid.len;
 346                         info->qop = gm->gm_pfs[i].qop;
 347                         info->service = gm->gm_pfs[i].service;
 348                         gss_mech_put(gm);
 349                         return 0;
 350                 }
 351         }
 352
 353         gss_mech_put(gm);
 354         return -ENOENT;
 355 }
 356
 357 u32
 358 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 359 {
 360         int i;
 361
 362         for (i = 0; i < gm->gm_pf_num; i++) {
 363                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 364                         return gm->gm_pfs[i].service;
 365         }
 366         return 0;
 367 }
 368 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
 369
 370 char *
 371 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 372 {
 373         int i;
 374
 375         for (i = 0; i < gm->gm_pf_num; i++) {
 376                 if (gm->gm_pfs[i].service == service)
 377                         return gm->gm_pfs[i].auth_domain_name;
 378         }
 379         return NULL;
 380 }
 381
 382 void
 383 gss_mech_put(struct gss_api_mech * gm)
 384 {
 385         if (gm)
 386                 module_put(gm->gm_owner);
 387 }
 388 EXPORT_SYMBOL(gss_mech_put);
 389
 390 /* The mech could probably be determined from the token instead, but it's just
 391  * as easy for now to pass it in. */
 392 int
 393 gss_import_sec_context(const void *input_token, size_t bufsize,
 394                        struct gss_api_mech      *mech,
 395                        struct gss_ctx           **ctx_id,
 396                        time_t                   *endtime,
 397                        gfp_t gfp_mask)
 398 {
 399         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 400                 return -ENOMEM;
 401         (*ctx_id)->mech_type = gss_mech_get(mech);
 402
 403         return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
 404                                                 *ctx_id, endtime, gfp_mask);
 405 }
 406
 407 /* gss_get_mic: compute a mic over message and return mic_token. */
 408
 409 u32
 410 gss_get_mic(struct gss_ctx      *context_handle,
 411             struct xdr_buf      *message,
 412             struct xdr_netobj   *mic_token)
 413 {
 414          return context_handle->mech_type->gm_ops
 415                 ->gss_get_mic(context_handle,
 416                               message,
 417                               mic_token);
 418 }
 419
 420 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 421
 422 u32
 423 gss_verify_mic(struct gss_ctx           *context_handle,
 424                struct xdr_buf           *message,
 425                struct xdr_netobj        *mic_token)
 426 {
 427         return context_handle->mech_type->gm_ops
 428                 ->gss_verify_mic(context_handle,
 429                                  message,
 430                                  mic_token);
 431 }
 432
 433 /*
 434  * This function is called from both the client and server code.
 435  * Each makes guarantees about how much "slack" space is available
 436  * for the underlying function in "buf"'s head and tail while
 437  * performing the wrap.
 438  *
 439  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 440  * space in both the head and tail which is available for use by
 441  * the wrap function.
 442  *
 443  * Underlying functions should verify they do not use more than
 444  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 445  * when performing the wrap.
 446  */
 447 u32
 448 gss_wrap(struct gss_ctx *ctx_id,
 449          int            offset,
 450          struct xdr_buf *buf,
 451          struct page    **inpages)
 452 {
 453         return ctx_id->mech_type->gm_ops
 454                 ->gss_wrap(ctx_id, offset, buf, inpages);
 455 }
 456
 457 u32
 458 gss_unwrap(struct gss_ctx       *ctx_id,
 459            int                  offset,
 460            struct xdr_buf       *buf)
 461 {
 462         return ctx_id->mech_type->gm_ops
 463                 ->gss_unwrap(ctx_id, offset, buf);
 464 }
 465
 466
 467 /* gss_delete_sec_context: free all resources associated with context_handle.
 468  * Note this differs from the RFC 2744-specified prototype in that we don't
 469  * bother returning an output token, since it would never be used anyway. */
 470
 471 u32
 472 gss_delete_sec_context(struct gss_ctx   **context_handle)
 473 {
 474         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 475                         *context_handle);
 476
 477         if (!*context_handle)
 478                 return GSS_S_NO_CONTEXT;
 479         if ((*context_handle)->internal_ctx_id)
 480                 (*context_handle)->mech_type->gm_ops
 481                         ->gss_delete_sec_context((*context_handle)
 482                                                         ->internal_ctx_id);
 483         gss_mech_put((*context_handle)->mech_type);
 484         kfree(*context_handle);
 485         *context_handle=NULL;
 486         return GSS_S_COMPLETE;
 487 }