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 #ifdef RPC_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                         module_put(pos->gm_owner);
 223                         continue;
 224                 }
 225                 if (try_module_get(pos->gm_owner))
 226                         gm = pos;
 227                 break;
 228         }
 229         spin_unlock(&registered_mechs_lock);
 230         return gm;
 231 }
 232
 233 struct gss_api_mech *
 234 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 235 {
 236         struct gss_api_mech *gm;
 237
 238         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 239
 240         if (!gm) {
 241                 request_module("rpc-auth-gss-%u", pseudoflavor);
 242                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 243         }
 244         return gm;
 245 }
 246
 247 /**
 248  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
 249  * @array: array to fill in
 250  * @size: size of "array"
 251  *
 252  * Returns the number of array items filled in, or a negative errno.
 253  *
 254  * The returned array is not sorted by any policy.  Callers should not
 255  * rely on the order of the items in the returned array.
 256  */
 257 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
 258 {
 259         struct gss_api_mech *pos = NULL;
 260         int j, i = 0;
 261
 262         spin_lock(&registered_mechs_lock);
 263         list_for_each_entry(pos, &registered_mechs, gm_list) {
 264                 for (j = 0; j < pos->gm_pf_num; j++) {
 265                         if (i >= size) {
 266                                 spin_unlock(&registered_mechs_lock);
 267                                 return -ENOMEM;
 268                         }
 269                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
 270                 }
 271         }
 272         spin_unlock(&registered_mechs_lock);
 273         return i;
 274 }
 275
 276 /**
 277  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
 278  * @gm: GSS mechanism handle
 279  * @qop: GSS quality-of-protection value
 280  * @service: GSS service value
 281  *
 282  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
 283  */
 284 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
 285                                          u32 service)
 286 {
 287         int i;
 288
 289         for (i = 0; i < gm->gm_pf_num; i++) {
 290                 if (gm->gm_pfs[i].qop == qop &&
 291                     gm->gm_pfs[i].service == service) {
 292                         return gm->gm_pfs[i].pseudoflavor;
 293                 }
 294         }
 295         return RPC_AUTH_MAXFLAVOR;
 296 }
 297
 298 /**
 299  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
 300  * @info: a GSS mech OID, quality of protection, and service value
 301  *
 302  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
 303  * not supported.
 304  */
 305 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
 306 {
 307         rpc_authflavor_t pseudoflavor;
 308         struct gss_api_mech *gm;
 309
 310         gm = gss_mech_get_by_OID(&info->oid);
 311         if (gm == NULL)
 312                 return RPC_AUTH_MAXFLAVOR;
 313
 314         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
 315
 316         gss_mech_put(gm);
 317         return pseudoflavor;
 318 }
 319
 320 /**
 321  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
 322  * @pseudoflavor: GSS pseudoflavor to match
 323  * @info: rpcsec_gss_info structure to fill in
 324  *
 325  * Returns zero and fills in "info" if pseudoflavor matches a
 326  * supported mechanism.  Otherwise a negative errno is returned.
 327  */
 328 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
 329                          struct rpcsec_gss_info *info)
 330 {
 331         struct gss_api_mech *gm;
 332         int i;
 333
 334         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
 335         if (gm == NULL)
 336                 return -ENOENT;
 337
 338         for (i = 0; i < gm->gm_pf_num; i++) {
 339                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
 340                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
 341                         info->oid.len = gm->gm_oid.len;
 342                         info->qop = gm->gm_pfs[i].qop;
 343                         info->service = gm->gm_pfs[i].service;
 344                         gss_mech_put(gm);
 345                         return 0;
 346                 }
 347         }
 348
 349         gss_mech_put(gm);
 350         return -ENOENT;
 351 }
 352
 353 u32
 354 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 355 {
 356         int i;
 357
 358         for (i = 0; i < gm->gm_pf_num; i++) {
 359                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 360                         return gm->gm_pfs[i].service;
 361         }
 362         return 0;
 363 }
 364 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
 365
 366 char *
 367 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 368 {
 369         int i;
 370
 371         for (i = 0; i < gm->gm_pf_num; i++) {
 372                 if (gm->gm_pfs[i].service == service)
 373                         return gm->gm_pfs[i].auth_domain_name;
 374         }
 375         return NULL;
 376 }
 377
 378 void
 379 gss_mech_put(struct gss_api_mech * gm)
 380 {
 381         if (gm)
 382                 module_put(gm->gm_owner);
 383 }
 384 EXPORT_SYMBOL(gss_mech_put);
 385
 386 /* The mech could probably be determined from the token instead, but it's just
 387  * as easy for now to pass it in. */
 388 int
 389 gss_import_sec_context(const void *input_token, size_t bufsize,
 390                        struct gss_api_mech      *mech,
 391                        struct gss_ctx           **ctx_id,
 392                        time_t                   *endtime,
 393                        gfp_t gfp_mask)
 394 {
 395         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 396                 return -ENOMEM;
 397         (*ctx_id)->mech_type = gss_mech_get(mech);
 398
 399         return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
 400                                                 *ctx_id, endtime, gfp_mask);
 401 }
 402
 403 /* gss_get_mic: compute a mic over message and return mic_token. */
 404
 405 u32
 406 gss_get_mic(struct gss_ctx      *context_handle,
 407             struct xdr_buf      *message,
 408             struct xdr_netobj   *mic_token)
 409 {
 410          return context_handle->mech_type->gm_ops
 411                 ->gss_get_mic(context_handle,
 412                               message,
 413                               mic_token);
 414 }
 415
 416 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 417
 418 u32
 419 gss_verify_mic(struct gss_ctx           *context_handle,
 420                struct xdr_buf           *message,
 421                struct xdr_netobj        *mic_token)
 422 {
 423         return context_handle->mech_type->gm_ops
 424                 ->gss_verify_mic(context_handle,
 425                                  message,
 426                                  mic_token);
 427 }
 428
 429 /*
 430  * This function is called from both the client and server code.
 431  * Each makes guarantees about how much "slack" space is available
 432  * for the underlying function in "buf"'s head and tail while
 433  * performing the wrap.
 434  *
 435  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 436  * space in both the head and tail which is available for use by
 437  * the wrap function.
 438  *
 439  * Underlying functions should verify they do not use more than
 440  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 441  * when performing the wrap.
 442  */
 443 u32
 444 gss_wrap(struct gss_ctx *ctx_id,
 445          int            offset,
 446          struct xdr_buf *buf,
 447          struct page    **inpages)
 448 {
 449         return ctx_id->mech_type->gm_ops
 450                 ->gss_wrap(ctx_id, offset, buf, inpages);
 451 }
 452
 453 u32
 454 gss_unwrap(struct gss_ctx       *ctx_id,
 455            int                  offset,
 456            struct xdr_buf       *buf)
 457 {
 458         return ctx_id->mech_type->gm_ops
 459                 ->gss_unwrap(ctx_id, offset, buf);
 460 }
 461
 462
 463 /* gss_delete_sec_context: free all resources associated with context_handle.
 464  * Note this differs from the RFC 2744-specified prototype in that we don't
 465  * bother returning an output token, since it would never be used anyway. */
 466
 467 u32
 468 gss_delete_sec_context(struct gss_ctx   **context_handle)
 469 {
 470         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 471                         *context_handle);
 472
 473         if (!*context_handle)
 474                 return GSS_S_NO_CONTEXT;
 475         if ((*context_handle)->internal_ctx_id)
 476                 (*context_handle)->mech_type->gm_ops
 477                         ->gss_delete_sec_context((*context_handle)
 478                                                         ->internal_ctx_id);
 479         gss_mech_put((*context_handle)->mech_type);
 480         kfree(*context_handle);
 481         *context_handle=NULL;
 482         return GSS_S_COMPLETE;
 483 }