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                 kfree(pf->auth_domain_name);
  41                 pf->auth_domain_name = NULL;
  42         }
  43 }
  44
  45 static inline char *
  46 make_auth_domain_name(char *name)
  47 {
  48         static char     *prefix = "gss/";
  49         char            *new;
  50
  51         new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
  52         if (new) {
  53                 strcpy(new, prefix);
  54                 strcat(new, name);
  55         }
  56         return new;
  57 }
  58
  59 static int
  60 gss_mech_svc_setup(struct gss_api_mech *gm)
  61 {
  62         struct pf_desc *pf;
  63         int i, status;
  64
  65         for (i = 0; i < gm->gm_pf_num; i++) {
  66                 pf = &gm->gm_pfs[i];
  67                 pf->auth_domain_name = make_auth_domain_name(pf->name);
  68                 status = -ENOMEM;
  69                 if (pf->auth_domain_name == NULL)
  70                         goto out;
  71                 status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
  72                                                         pf->auth_domain_name);
  73                 if (status)
  74                         goto out;
  75         }
  76         return 0;
  77 out:
  78         gss_mech_free(gm);
  79         return status;
  80 }
  81
  82 /**
  83  * gss_mech_register - register a GSS mechanism
  84  * @gm: GSS mechanism handle
  85  *
  86  * Returns zero if successful, or a negative errno.
  87  */
  88 int gss_mech_register(struct gss_api_mech *gm)
  89 {
  90         int status;
  91
  92         status = gss_mech_svc_setup(gm);
  93         if (status)
  94                 return status;
  95         spin_lock(&registered_mechs_lock);
  96         list_add_rcu(&gm->gm_list, &registered_mechs);
  97         spin_unlock(&registered_mechs_lock);
  98         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
  99         return 0;
 100 }
 101 EXPORT_SYMBOL_GPL(gss_mech_register);
 102
 103 /**
 104  * gss_mech_unregister - release a GSS mechanism
 105  * @gm: GSS mechanism handle
 106  *
 107  */
 108 void gss_mech_unregister(struct gss_api_mech *gm)
 109 {
 110         spin_lock(&registered_mechs_lock);
 111         list_del_rcu(&gm->gm_list);
 112         spin_unlock(&registered_mechs_lock);
 113         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
 114         gss_mech_free(gm);
 115 }
 116 EXPORT_SYMBOL_GPL(gss_mech_unregister);
 117
 118 struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
 119 {
 120         __module_get(gm->gm_owner);
 121         return gm;
 122 }
 123 EXPORT_SYMBOL(gss_mech_get);
 124
 125 static struct gss_api_mech *
 126 _gss_mech_get_by_name(const char *name)
 127 {
 128         struct gss_api_mech     *pos, *gm = NULL;
 129
 130         rcu_read_lock();
 131         list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 132                 if (0 == strcmp(name, pos->gm_name)) {
 133                         if (try_module_get(pos->gm_owner))
 134                                 gm = pos;
 135                         break;
 136                 }
 137         }
 138         rcu_read_unlock();
 139         return gm;
 140
 141 }
 142
 143 struct gss_api_mech * gss_mech_get_by_name(const char *name)
 144 {
 145         struct gss_api_mech *gm = NULL;
 146
 147         gm = _gss_mech_get_by_name(name);
 148         if (!gm) {
 149                 request_module("rpc-auth-gss-%s", name);
 150                 gm = _gss_mech_get_by_name(name);
 151         }
 152         return gm;
 153 }
 154
 155 struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
 156 {
 157         struct gss_api_mech     *pos, *gm = NULL;
 158         char buf[32];
 159
 160         if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
 161                 return NULL;
 162         request_module("rpc-auth-gss-%s", buf);
 163
 164         rcu_read_lock();
 165         list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 166                 if (obj->len == pos->gm_oid.len) {
 167                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
 168                                 if (try_module_get(pos->gm_owner))
 169                                         gm = pos;
 170                                 break;
 171                         }
 172                 }
 173         }
 174         rcu_read_unlock();
 175         if (!gm)
 176                 trace_rpcgss_oid_to_mech(buf);
 177         return gm;
 178 }
 179
 180 static inline int
 181 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
 182 {
 183         int i;
 184
 185         for (i = 0; i < gm->gm_pf_num; i++) {
 186                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 187                         return 1;
 188         }
 189         return 0;
 190 }
 191
 192 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 193 {
 194         struct gss_api_mech *gm = NULL, *pos;
 195
 196         rcu_read_lock();
 197         list_for_each_entry_rcu(pos, &registered_mechs, gm_list) {
 198                 if (!mech_supports_pseudoflavor(pos, pseudoflavor))
 199                         continue;
 200                 if (try_module_get(pos->gm_owner))
 201                         gm = pos;
 202                 break;
 203         }
 204         rcu_read_unlock();
 205         return gm;
 206 }
 207
 208 struct gss_api_mech *
 209 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
 210 {
 211         struct gss_api_mech *gm;
 212
 213         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 214
 215         if (!gm) {
 216                 request_module("rpc-auth-gss-%u", pseudoflavor);
 217                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
 218         }
 219         return gm;
 220 }
 221
 222 /**
 223  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
 224  * @gm: GSS mechanism handle
 225  * @qop: GSS quality-of-protection value
 226  * @service: GSS service value
 227  *
 228  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
 229  */
 230 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
 231                                          u32 service)
 232 {
 233         int i;
 234
 235         for (i = 0; i < gm->gm_pf_num; i++) {
 236                 if (gm->gm_pfs[i].qop == qop &&
 237                     gm->gm_pfs[i].service == service) {
 238                         return gm->gm_pfs[i].pseudoflavor;
 239                 }
 240         }
 241         return RPC_AUTH_MAXFLAVOR;
 242 }
 243
 244 /**
 245  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
 246  * @info: a GSS mech OID, quality of protection, and service value
 247  *
 248  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
 249  * not supported.
 250  */
 251 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
 252 {
 253         rpc_authflavor_t pseudoflavor;
 254         struct gss_api_mech *gm;
 255
 256         gm = gss_mech_get_by_OID(&info->oid);
 257         if (gm == NULL)
 258                 return RPC_AUTH_MAXFLAVOR;
 259
 260         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
 261
 262         gss_mech_put(gm);
 263         return pseudoflavor;
 264 }
 265
 266 /**
 267  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
 268  * @pseudoflavor: GSS pseudoflavor to match
 269  * @info: rpcsec_gss_info structure to fill in
 270  *
 271  * Returns zero and fills in "info" if pseudoflavor matches a
 272  * supported mechanism.  Otherwise a negative errno is returned.
 273  */
 274 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
 275                          struct rpcsec_gss_info *info)
 276 {
 277         struct gss_api_mech *gm;
 278         int i;
 279
 280         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
 281         if (gm == NULL)
 282                 return -ENOENT;
 283
 284         for (i = 0; i < gm->gm_pf_num; i++) {
 285                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
 286                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
 287                         info->oid.len = gm->gm_oid.len;
 288                         info->qop = gm->gm_pfs[i].qop;
 289                         info->service = gm->gm_pfs[i].service;
 290                         gss_mech_put(gm);
 291                         return 0;
 292                 }
 293         }
 294
 295         gss_mech_put(gm);
 296         return -ENOENT;
 297 }
 298
 299 u32
 300 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 301 {
 302         int i;
 303
 304         for (i = 0; i < gm->gm_pf_num; i++) {
 305                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 306                         return gm->gm_pfs[i].service;
 307         }
 308         return 0;
 309 }
 310 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
 311
 312 bool
 313 gss_pseudoflavor_to_datatouch(struct gss_api_mech *gm, u32 pseudoflavor)
 314 {
 315         int i;
 316
 317         for (i = 0; i < gm->gm_pf_num; i++) {
 318                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
 319                         return gm->gm_pfs[i].datatouch;
 320         }
 321         return false;
 322 }
 323
 324 char *
 325 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
 326 {
 327         int i;
 328
 329         for (i = 0; i < gm->gm_pf_num; i++) {
 330                 if (gm->gm_pfs[i].service == service)
 331                         return gm->gm_pfs[i].auth_domain_name;
 332         }
 333         return NULL;
 334 }
 335
 336 void
 337 gss_mech_put(struct gss_api_mech * gm)
 338 {
 339         if (gm)
 340                 module_put(gm->gm_owner);
 341 }
 342 EXPORT_SYMBOL(gss_mech_put);
 343
 344 /* The mech could probably be determined from the token instead, but it's just
 345  * as easy for now to pass it in. */
 346 int
 347 gss_import_sec_context(const void *input_token, size_t bufsize,
 348                        struct gss_api_mech      *mech,
 349                        struct gss_ctx           **ctx_id,
 350                        time64_t                 *endtime,
 351                        gfp_t gfp_mask)
 352 {
 353         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
 354                 return -ENOMEM;
 355         (*ctx_id)->mech_type = gss_mech_get(mech);
 356
 357         return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
 358                                                 *ctx_id, endtime, gfp_mask);
 359 }
 360
 361 /* gss_get_mic: compute a mic over message and return mic_token. */
 362
 363 u32
 364 gss_get_mic(struct gss_ctx      *context_handle,
 365             struct xdr_buf      *message,
 366             struct xdr_netobj   *mic_token)
 367 {
 368          return context_handle->mech_type->gm_ops
 369                 ->gss_get_mic(context_handle,
 370                               message,
 371                               mic_token);
 372 }
 373
 374 /* gss_verify_mic: check whether the provided mic_token verifies message. */
 375
 376 u32
 377 gss_verify_mic(struct gss_ctx           *context_handle,
 378                struct xdr_buf           *message,
 379                struct xdr_netobj        *mic_token)
 380 {
 381         return context_handle->mech_type->gm_ops
 382                 ->gss_verify_mic(context_handle,
 383                                  message,
 384                                  mic_token);
 385 }
 386
 387 /*
 388  * This function is called from both the client and server code.
 389  * Each makes guarantees about how much "slack" space is available
 390  * for the underlying function in "buf"'s head and tail while
 391  * performing the wrap.
 392  *
 393  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
 394  * space in both the head and tail which is available for use by
 395  * the wrap function.
 396  *
 397  * Underlying functions should verify they do not use more than
 398  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
 399  * when performing the wrap.
 400  */
 401 u32
 402 gss_wrap(struct gss_ctx *ctx_id,
 403          int            offset,
 404          struct xdr_buf *buf,
 405          struct page    **inpages)
 406 {
 407         return ctx_id->mech_type->gm_ops
 408                 ->gss_wrap(ctx_id, offset, buf, inpages);
 409 }
 410
 411 u32
 412 gss_unwrap(struct gss_ctx       *ctx_id,
 413            int                  offset,
 414            struct xdr_buf       *buf)
 415 {
 416         return ctx_id->mech_type->gm_ops
 417                 ->gss_unwrap(ctx_id, offset, buf);
 418 }
 419
 420
 421 /* gss_delete_sec_context: free all resources associated with context_handle.
 422  * Note this differs from the RFC 2744-specified prototype in that we don't
 423  * bother returning an output token, since it would never be used anyway. */
 424
 425 u32
 426 gss_delete_sec_context(struct gss_ctx   **context_handle)
 427 {
 428         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
 429                         *context_handle);
 430
 431         if (!*context_handle)
 432                 return GSS_S_NO_CONTEXT;
 433         if ((*context_handle)->internal_ctx_id)
 434                 (*context_handle)->mech_type->gm_ops
 435                         ->gss_delete_sec_context((*context_handle)
 436                                                         ->internal_ctx_id);
 437         gss_mech_put((*context_handle)->mech_type);
 438         kfree(*context_handle);
 439         *context_handle=NULL;
 440         return GSS_S_COMPLETE;
 441 }