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                 kfree(pf->auth_domain_name);
  65                 pf->auth_domain_name = NULL;
  66         }
  67 }
  68
  69 static inline char *
  70 make_auth_domain_name(char *name)
  71 {
  72         static char     *prefix = "gss/";
  73         char            *new;
  74
  75         new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
  76         if (new) {
  77                 strcpy(new, prefix);
  78                 strcat(new, name);
  79         }
  80         return new;
  81 }
  82
  83 static int
  84 gss_mech_svc_setup(struct gss_api_mech *gm)
  85 {
  86         struct pf_desc *pf;
  87         int i, status;
  88
  89         for (i = 0; i < gm->gm_pf_num; i++) {
  90                 pf = &gm->gm_pfs[i];
  91                 pf->auth_domain_name = make_auth_domain_name(pf->name);
  92                 status = -ENOMEM;
  93                 if (pf->auth_domain_name == NULL)
  94                         goto out;
  95                 status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
  96                                                         pf->auth_domain_name);
  97                 if (status)
  98                         goto out;
  99         }
 100         return 0;
 101 out:
 102         gss_mech_free(gm);
 103         return status;
 104 }
 105
 106 /**
 107  * gss_mech_register - register a GSS mechanism
 108  * @gm: GSS mechanism handle
 109  *
 110  * Returns zero if successful, or a negative errno.
 111  */
 112 int gss_mech_register(struct gss_api_mech *gm)
 113 {
 114         int status;
 115
 116         status = gss_mech_svc_setup(gm);
 117         if (status)
 118                 return status;
 119         spin_lock(&registered_mechs_lock);
 120         list_add(&gm->gm_list, &registered_mechs);
 121         spin_unlock(&registered_mechs_lock);
 122         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
 123         return 0;
 124 }
 125 EXPORT_SYMBOL_GPL(gss_mech_register);
 126
 127 /**
 128  * gss_mech_unregister - release a GSS mechanism
 129  * @gm: GSS mechanism handle
 130  *
 131  */
 132 void gss_mech_unregister(struct gss_api_mech *gm)
 133 {
 134         spin_lock(&registered_mechs_lock);
 135         list_del(&gm->gm_list);
 136         spin_unlock(&registered_mechs_lock);
 137         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 138         gss_mech_free(gm);
 139 }
 140 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 141
 142 struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
 143 {
 144         __module_get(gm->gm_owner);
 145         return gm;
 146 }
 147 EXPORT_SYMBOL(gss_mech_get);
 148
 149 static struct gss_api_mech *
 150 _gss_mech_get_by_name(const char *name)
 151 {
 152         struct gss_api_mech     *pos, *gm = NULL;
 153
 154         spin_lock(&registered_mechs_lock);
 155         list_for_each_entry(pos, &registered_mechs, gm_list) {
 156                 if (0 == strcmp(name, pos->gm_name)) {
 157                         if (try_module_get(pos->gm_owner))
 158                                 gm = pos;
 159                         break;
 160                 }
 161         }
 162         spin_unlock(&registered_mechs_lock);
 163         return gm;
 164
 165 }
 166
 167 struct gss_api_mech * gss_mech_get_by_name(const char *name)
 168 {
 169         struct gss_api_mech *gm = NULL;
 170
 171         gm = _gss_mech_get_by_name(name);
 172         if (!gm) {
 173                 request_module("rpc-auth-gss-%s", name);
 174                 gm = _gss_mech_get_by_name(name);
 175         }
 176         return gm;
 177 }
 178
 179 struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 180 {
 181         struct gss_api_mech     *pos, *gm = NULL;
 182         char buf[32];
 183
 184         if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
 185                 return NULL;
 186         dprintk("RPC:       %s(%s)\n", __func__, buf);
 187         request_module("rpc-auth-gss-%s", buf);
 188
 189         spin_lock(&registered_mechs_lock);
 190         list_for_each_entry(pos, &registered_mechs, gm_list) {
 191                 if (obj->len == pos->gm_oid.len) {
 192                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 193                                 if (try_module_get(pos->gm_owner))
 194                                         gm = pos;
 195                                 break;
 196                         }
 197                 }
 198         }
 199         spin_unlock(&registered_mechs_lock);
 200         return gm;
 201 }
 202
 203 static inline int
 204 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 205 {
 206         int i;
 207
 208         for (i = 0; i < gm->gm_pf_num; i++) {
 209                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 210                         return 1;
 211         }
 212         return 0;
 213 }
 214
 215 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 216 {
 217         struct gss_api_mech *gm = NULL, *pos;
 218
 219         spin_lock(&registered_mechs_lock);
 220         list_for_each_entry(pos, &registered_mechs, gm_list) {
 221                 if (!mech_supports_pseudoflavor(pos, pseudoflavor))
 222                         continue;
 223                 if (try_module_get(pos->gm_owner))
 224                         gm = pos;
 225                 break;
 226         }
 227         spin_unlock(&registered_mechs_lock);
 228         return gm;
 229 }
 230
 231 struct gss_api_mech *
 232 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 233 {
 234         struct gss_api_mech *gm;
 235
 236         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 237
 238         if (!gm) {
 239                 request_module("rpc-auth-gss-%u", pseudoflavor);
 240                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 241         }
 242         return gm;
 243 }
 244
 245 /**
 246  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
 247  * @array: array to fill in
 248  * @size: size of "array"
 249  *
 250  * Returns the number of array items filled in, or a negative errno.
 251  *
 252  * The returned array is not sorted by any policy.  Callers should not
 253  * rely on the order of the items in the returned array.
 254  */
 255 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 256 {
 257         struct gss_api_mech *pos = NULL;
 258         int j, i = 0;
 259
 260         spin_lock(&registered_mechs_lock);
 261         list_for_each_entry(pos, &registered_mechs, gm_list) {
 262                 for (j = 0; j < pos->gm_pf_num; j++) {
 263                         if (i >= size) {
 264                                 spin_unlock(&registered_mechs_lock);
 265                                 return -ENOMEM;
 266                         }
 267                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 268                 }
 269         }
 270         spin_unlock(&registered_mechs_lock);
 271         return i;
 272 }
 273
 274 /**
 275  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
 276  * @gm: GSS mechanism handle
 277  * @qop: GSS quality-of-protection value
 278  * @service: GSS service value
 279  *
 280  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
 281  */
 282 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
 283                                          u32 service)
 284 {
 285         int i;
 286
 287         for (i = 0; i < gm->gm_pf_num; i++) {
 288                 if (gm->gm_pfs[i].qop == qop &&
 289                     gm->gm_pfs[i].service == service) {
 290                         return gm->gm_pfs[i].pseudoflavor;
 291                 }
 292         }
 293         return RPC_AUTH_MAXFLAVOR;
 294 }
 295
 296 /**
 297  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
 298  * @info: a GSS mech OID, quality of protection, and service value
 299  *
 300  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
 301  * not supported.
 302  */
 303 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
 304 {
 305         rpc_authflavor_t pseudoflavor;
 306         struct gss_api_mech *gm;
 307
 308         gm = gss_mech_get_by_OID(&info->oid);
 309         if (gm == NULL)
 310                 return RPC_AUTH_MAXFLAVOR;
 311
 312         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
 313
 314         gss_mech_put(gm);
 315         return pseudoflavor;
 316 }
 317
 318 /**
 319  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
 320  * @pseudoflavor: GSS pseudoflavor to match
 321  * @info: rpcsec_gss_info structure to fill in
 322  *
 323  * Returns zero and fills in "info" if pseudoflavor matches a
 324  * supported mechanism.  Otherwise a negative errno is returned.
 325  */
 326 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
 327                          struct rpcsec_gss_info *info)
 328 {
 329         struct gss_api_mech *gm;
 330         int i;
 331
 332         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
 333         if (gm == NULL)
 334                 return -ENOENT;
 335
 336         for (i = 0; i < gm->gm_pf_num; i++) {
 337                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
 338                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
 339                         info->oid.len = gm->gm_oid.len;
 340                         info->qop = gm->gm_pfs[i].qop;
 341                         info->service = gm->gm_pfs[i].service;
 342                         gss_mech_put(gm);
 343                         return 0;
 344                 }
 345         }
 346
 347         gss_mech_put(gm);
 348         return -ENOENT;
 349 }
 350
 351 u32
 352 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 353 {
 354         int i;
 355
 356         for (i = 0; i < gm->gm_pf_num; i++) {
 357                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 358                         return gm->gm_pfs[i].service;
 359         }
 360         return 0;
 361 }
 362 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
 363
 364 char *
 365 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 366 {
 367         int i;
 368
 369         for (i = 0; i < gm->gm_pf_num; i++) {
 370                 if (gm->gm_pfs[i].service == service)
 371                         return gm->gm_pfs[i].auth_domain_name;
 372         }
 373         return NULL;
 374 }
 375
 376 void
 377 gss_mech_put(struct gss_api_mech * gm)
 378 {
 379         if (gm)
 380                 module_put(gm->gm_owner);
 381 }
 382 EXPORT_SYMBOL(gss_mech_put);
 383
 384 /* The mech could probably be determined from the token instead, but it's just
 385  * as easy for now to pass it in. */
 386 int
 387 gss_import_sec_context(const void *input_token, size_t bufsize,
 388                        struct gss_api_mech      *mech,
 389                        struct gss_ctx           **ctx_id,
 390                        time_t                   *endtime,
 391                        gfp_t gfp_mask)
 392 {
 393         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 394                 return -ENOMEM;
 395         (*ctx_id)->mech_type = gss_mech_get(mech);
 396
 397         return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
 398                                                 *ctx_id, endtime, gfp_mask);
 399 }
 400
 401 /* gss_get_mic: compute a mic over message and return mic_token. */
 402
 403 u32
 404 gss_get_mic(struct gss_ctx      *context_handle,
 405             struct xdr_buf      *message,
 406             struct xdr_netobj   *mic_token)
 407 {
 408          return context_handle->mech_type->gm_ops
 409                 ->gss_get_mic(context_handle,
 410                               message,
 411                               mic_token);
 412 }
 413
 414 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 415
 416 u32
 417 gss_verify_mic(struct gss_ctx           *context_handle,
 418                struct xdr_buf           *message,
 419                struct xdr_netobj        *mic_token)
 420 {
 421         return context_handle->mech_type->gm_ops
 422                 ->gss_verify_mic(context_handle,
 423                                  message,
 424                                  mic_token);
 425 }
 426
 427 /*
 428  * This function is called from both the client and server code.
 429  * Each makes guarantees about how much "slack" space is available
 430  * for the underlying function in "buf"'s head and tail while
 431  * performing the wrap.
 432  *
 433  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 434  * space in both the head and tail which is available for use by
 435  * the wrap function.
 436  *
 437  * Underlying functions should verify they do not use more than
 438  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 439  * when performing the wrap.
 440  */
 441 u32
 442 gss_wrap(struct gss_ctx *ctx_id,
 443          int            offset,
 444          struct xdr_buf *buf,
 445          struct page    **inpages)
 446 {
 447         return ctx_id->mech_type->gm_ops
 448                 ->gss_wrap(ctx_id, offset, buf, inpages);
 449 }
 450
 451 u32
 452 gss_unwrap(struct gss_ctx       *ctx_id,
 453            int                  offset,
 454            struct xdr_buf       *buf)
 455 {
 456         return ctx_id->mech_type->gm_ops
 457                 ->gss_unwrap(ctx_id, offset, buf);
 458 }
 459
 460
 461 /* gss_delete_sec_context: free all resources associated with context_handle.
 462  * Note this differs from the RFC 2744-specified prototype in that we don't
 463  * bother returning an output token, since it would never be used anyway. */
 464
 465 u32
 466 gss_delete_sec_context(struct gss_ctx   **context_handle)
 467 {
 468         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 469                         *context_handle);
 470
 471         if (!*context_handle)
 472                 return GSS_S_NO_CONTEXT;
 473         if ((*context_handle)->internal_ctx_id)
 474                 (*context_handle)->mech_type->gm_ops
 475                         ->gss_delete_sec_context((*context_handle)
 476                                                         ->internal_ctx_id);
 477         gss_mech_put((*context_handle)->mech_type);
 478         kfree(*context_handle);
 479         *context_handle=NULL;
 480         return GSS_S_COMPLETE;
 481 }