crypto/core_namemap.c

   1 /*
   2  * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include "e_os.h"                /* strcasecmp */
  11 #include "internal/namemap.h"
  12 #include <openssl/lhash.h>
  13 #include "crypto/lhash.h"      /* ossl_lh_strcasehash */
  14 #include "internal/tsan_assist.h"
  15
  16 /*-
  17  * The namenum entry
  18  * =================
  19  */
  20 typedef struct {
  21     char *name;
  22     int number;
  23 } NAMENUM_ENTRY;
  24
  25 DEFINE_LHASH_OF(NAMENUM_ENTRY);
  26
  27 /*-
  28  * The namemap itself
  29  * ==================
  30  */
  31
  32 struct ossl_namemap_st {
  33     /* Flags */
  34     unsigned int stored:1; /* If 1, it's stored in a library context */
  35
  36     CRYPTO_RWLOCK *lock;
  37     LHASH_OF(NAMENUM_ENTRY) *namenum;  /* Name->number mapping */
  38
  39 #ifdef tsan_ld_acq
  40     TSAN_QUALIFIER int max_number;     /* Current max number TSAN version */
  41 #else
  42     int max_number;                    /* Current max number plain version */
  43 #endif
  44 };
  45
  46 /* LHASH callbacks */
  47
  48 static unsigned long namenum_hash(const NAMENUM_ENTRY *n)
  49 {
  50     return ossl_lh_strcasehash(n->name);
  51 }
  52
  53 static int namenum_cmp(const NAMENUM_ENTRY *a, const NAMENUM_ENTRY *b)
  54 {
  55     return strcasecmp(a->name, b->name);
  56 }
  57
  58 static void namenum_free(NAMENUM_ENTRY *n)
  59 {
  60     if (n != NULL)
  61         OPENSSL_free(n->name);
  62     OPENSSL_free(n);
  63 }
  64
  65 /* OSSL_LIB_CTX_METHOD functions for a namemap stored in a library context */
  66
  67 static void *stored_namemap_new(OSSL_LIB_CTX *libctx)
  68 {
  69     OSSL_NAMEMAP *namemap = ossl_namemap_new();
  70
  71     if (namemap != NULL)
  72         namemap->stored = 1;
  73
  74     return namemap;
  75 }
  76
  77 static void stored_namemap_free(void *vnamemap)
  78 {
  79     OSSL_NAMEMAP *namemap = vnamemap;
  80
  81     if (namemap != NULL) {
  82         /* Pretend it isn't stored, or ossl_namemap_free() will do nothing */
  83         namemap->stored = 0;
  84         ossl_namemap_free(namemap);
  85     }
  86 }
  87
  88 static const OSSL_LIB_CTX_METHOD stored_namemap_method = {
  89     stored_namemap_new,
  90     stored_namemap_free,
  91 };
  92
  93 /*-
  94  * API functions
  95  * =============
  96  */
  97
  98 int ossl_namemap_empty(OSSL_NAMEMAP *namemap)
  99 {
 100 #ifdef tsan_ld_acq
 101     /* Have TSAN support */
 102     return namemap == NULL || tsan_load(&namemap->max_number) == 0;
 103 #else
 104     /* No TSAN support */
 105     int rv;
 106
 107     if (namemap == NULL)
 108         return 1;
 109
 110     if (!CRYPTO_THREAD_read_lock(namemap->lock))
 111         return -1;
 112     rv = namemap->max_number == 0;
 113     CRYPTO_THREAD_unlock(namemap->lock);
 114     return rv;
 115 #endif
 116 }
 117
 118 typedef struct doall_names_data_st {
 119     int number;
 120     const char **names;
 121     int found;
 122 } DOALL_NAMES_DATA;
 123
 124 static void do_name(const NAMENUM_ENTRY *namenum, DOALL_NAMES_DATA *data)
 125 {
 126     if (namenum->number == data->number)
 127         data->names[data->found++] = namenum->name;
 128 }
 129
 130 IMPLEMENT_LHASH_DOALL_ARG_CONST(NAMENUM_ENTRY, DOALL_NAMES_DATA);
 131
 132 /*
 133  * Call the callback for all names in the namemap with the given number.
 134  * A return value 1 means that the callback was called for all names. A
 135  * return value of 0 means that the callback was not called for any names.
 136  */
 137 int ossl_namemap_doall_names(const OSSL_NAMEMAP *namemap, int number,
 138                              void (*fn)(const char *name, void *data),
 139                              void *data)
 140 {
 141     DOALL_NAMES_DATA cbdata;
 142     size_t num_names;
 143     int i;
 144
 145     cbdata.number = number;
 146     cbdata.found = 0;
 147
 148     /*
 149      * We collect all the names first under a read lock. Subsequently we call
 150      * the user function, so that we're not holding the read lock when in user
 151      * code. This could lead to deadlocks.
 152      */
 153     if (!CRYPTO_THREAD_read_lock(namemap->lock))
 154         return 0;
 155
 156     num_names = lh_NAMENUM_ENTRY_num_items(namemap->namenum);
 157     if (num_names == 0) {
 158         CRYPTO_THREAD_unlock(namemap->lock);
 159         return 0;
 160     }
 161     cbdata.names = OPENSSL_malloc(sizeof(*cbdata.names) * num_names);
 162     if (cbdata.names == NULL) {
 163         CRYPTO_THREAD_unlock(namemap->lock);
 164         return 0;
 165     }
 166     lh_NAMENUM_ENTRY_doall_DOALL_NAMES_DATA(namemap->namenum, do_name,
 167                                             &cbdata);
 168     CRYPTO_THREAD_unlock(namemap->lock);
 169
 170     for (i = 0; i < cbdata.found; i++)
 171         fn(cbdata.names[i], data);
 172
 173     OPENSSL_free(cbdata.names);
 174     return 1;
 175 }
 176
 177 static int namemap_name2num_n(const OSSL_NAMEMAP *namemap,
 178                               const char *name, size_t name_len)
 179 {
 180     NAMENUM_ENTRY *namenum_entry, namenum_tmpl;
 181
 182     if ((namenum_tmpl.name = OPENSSL_strndup(name, name_len)) == NULL)
 183         return 0;
 184     namenum_tmpl.number = 0;
 185     namenum_entry =
 186         lh_NAMENUM_ENTRY_retrieve(namemap->namenum, &namenum_tmpl);
 187     OPENSSL_free(namenum_tmpl.name);
 188     return namenum_entry != NULL ? namenum_entry->number : 0;
 189 }
 190
 191 int ossl_namemap_name2num_n(const OSSL_NAMEMAP *namemap,
 192                             const char *name, size_t name_len)
 193 {
 194     int number;
 195
 196 #ifndef FIPS_MODULE
 197     if (namemap == NULL)
 198         namemap = ossl_namemap_stored(NULL);
 199 #endif
 200
 201     if (namemap == NULL)
 202         return 0;
 203
 204     if (!CRYPTO_THREAD_read_lock(namemap->lock))
 205         return 0;
 206     number = namemap_name2num_n(namemap, name, name_len);
 207     CRYPTO_THREAD_unlock(namemap->lock);
 208
 209     return number;
 210 }
 211
 212 int ossl_namemap_name2num(const OSSL_NAMEMAP *namemap, const char *name)
 213 {
 214     if (name == NULL)
 215         return 0;
 216
 217     return ossl_namemap_name2num_n(namemap, name, strlen(name));
 218 }
 219
 220 struct num2name_data_st {
 221     size_t idx;                  /* Countdown */
 222     const char *name;            /* Result */
 223 };
 224
 225 static void do_num2name(const char *name, void *vdata)
 226 {
 227     struct num2name_data_st *data = vdata;
 228
 229     if (data->idx > 0)
 230         data->idx--;
 231     else if (data->name == NULL)
 232         data->name = name;
 233 }
 234
 235 const char *ossl_namemap_num2name(const OSSL_NAMEMAP *namemap, int number,
 236                                   size_t idx)
 237 {
 238     struct num2name_data_st data;
 239
 240     data.idx = idx;
 241     data.name = NULL;
 242     if (!ossl_namemap_doall_names(namemap, number, do_num2name, &data))
 243         return NULL;
 244     return data.name;
 245 }
 246
 247 static int namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
 248                               const char *name, size_t name_len)
 249 {
 250     NAMENUM_ENTRY *namenum = NULL;
 251     int tmp_number;
 252
 253     /* If it already exists, we don't add it */
 254     if ((tmp_number = namemap_name2num_n(namemap, name, name_len)) != 0)
 255         return tmp_number;
 256
 257     if ((namenum = OPENSSL_zalloc(sizeof(*namenum))) == NULL
 258         || (namenum->name = OPENSSL_strndup(name, name_len)) == NULL)
 259         goto err;
 260
 261     namenum->number =
 262         number != 0 ? number : 1 + tsan_counter(&namemap->max_number);
 263     (void)lh_NAMENUM_ENTRY_insert(namemap->namenum, namenum);
 264
 265     if (lh_NAMENUM_ENTRY_error(namemap->namenum))
 266         goto err;
 267     return namenum->number;
 268
 269  err:
 270     namenum_free(namenum);
 271     return 0;
 272 }
 273
 274 int ossl_namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
 275                             const char *name, size_t name_len)
 276 {
 277     int tmp_number;
 278
 279 #ifndef FIPS_MODULE
 280     if (namemap == NULL)
 281         namemap = ossl_namemap_stored(NULL);
 282 #endif
 283
 284     if (name == NULL || name_len == 0 || namemap == NULL)
 285         return 0;
 286
 287     if (!CRYPTO_THREAD_write_lock(namemap->lock))
 288         return 0;
 289     tmp_number = namemap_add_name_n(namemap, number, name, name_len);
 290     CRYPTO_THREAD_unlock(namemap->lock);
 291     return tmp_number;
 292 }
 293
 294 int ossl_namemap_add_name(OSSL_NAMEMAP *namemap, int number, const char *name)
 295 {
 296     if (name == NULL)
 297         return 0;
 298
 299     return ossl_namemap_add_name_n(namemap, number, name, strlen(name));
 300 }
 301
 302 int ossl_namemap_add_names(OSSL_NAMEMAP *namemap, int number,
 303                            const char *names, const char separator)
 304 {
 305     const char *p, *q;
 306     size_t l;
 307
 308     /* Check that we have a namemap */
 309     if (!ossl_assert(namemap != NULL)) {
 310         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
 311         return 0;
 312     }
 313
 314     if (!CRYPTO_THREAD_write_lock(namemap->lock))
 315         return 0;
 316     /*
 317      * Check that no name is an empty string, and that all names have at
 318      * most one numeric identity together.
 319      */
 320     for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
 321         int this_number;
 322
 323         if ((q = strchr(p, separator)) == NULL)
 324             l = strlen(p);       /* offset to \0 */
 325         else
 326             l = q - p;           /* offset to the next separator */
 327
 328         this_number = namemap_name2num_n(namemap, p, l);
 329
 330         if (*p == '\0' || *p == separator) {
 331             ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_BAD_ALGORITHM_NAME);
 332             goto err;
 333         }
 334         if (number == 0) {
 335             number = this_number;
 336         } else if (this_number != 0 && this_number != number) {
 337             ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_CONFLICTING_NAMES,
 338                            "\"%.*s\" has an existing different identity %d (from \"%s\")",
 339                            l, p, this_number, names);
 340             goto err;
 341         }
 342     }
 343
 344     /* Now that we have checked, register all names */
 345     for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
 346         int this_number;
 347
 348         if ((q = strchr(p, separator)) == NULL)
 349             l = strlen(p);       /* offset to \0 */
 350         else
 351             l = q - p;           /* offset to the next separator */
 352
 353         this_number = namemap_add_name_n(namemap, number, p, l);
 354         if (number == 0) {
 355             number = this_number;
 356         } else if (this_number != number) {
 357             ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR,
 358                            "Got number %d when expecting %d",
 359                            this_number, number);
 360             goto err;
 361         }
 362     }
 363
 364     CRYPTO_THREAD_unlock(namemap->lock);
 365     return number;
 366
 367  err:
 368     CRYPTO_THREAD_unlock(namemap->lock);
 369     return 0;
 370 }
 371
 372 /*-
 373  * Pre-population
 374  * ==============
 375  */
 376
 377 #ifndef FIPS_MODULE
 378 #include <openssl/evp.h>
 379
 380 /* Creates an initial namemap with names found in the legacy method db */
 381 static void get_legacy_evp_names(const char *main_name, const char *alias,
 382                                  void *arg)
 383 {
 384     int main_id = ossl_namemap_add_name(arg, 0, main_name);
 385
 386     /*
 387      * We could check that the returned value is the same as main_id,
 388      * but since this is a void function, there's no sane way to report
 389      * the error.  The best we can do is trust ourselve to keep the legacy
 390      * method database conflict free.
 391      *
 392      * This registers any alias with the same number as the main name.
 393      * Should it be that the current |on| *has* the main name, this is
 394      * simply a no-op.
 395      */
 396     if (alias != NULL) {
 397         (void)ossl_namemap_add_name(arg, main_id, alias);
 398     }
 399 }
 400
 401 static void get_legacy_cipher_names(const OBJ_NAME *on, void *arg)
 402 {
 403     const EVP_CIPHER *cipher = (void *)OBJ_NAME_get(on->name, on->type);
 404
 405     get_legacy_evp_names(EVP_CIPHER_name(cipher), on->name, arg);
 406 }
 407
 408 static void get_legacy_md_names(const OBJ_NAME *on, void *arg)
 409 {
 410     const EVP_MD *md = (void *)OBJ_NAME_get(on->name, on->type);
 411     /* We don't want the pkey_type names, so we need some extra care */
 412     int snid, lnid;
 413
 414     snid = OBJ_sn2nid(on->name);
 415     lnid = OBJ_ln2nid(on->name);
 416     if (snid != EVP_MD_pkey_type(md) && lnid != EVP_MD_pkey_type(md))
 417         get_legacy_evp_names(EVP_MD_name(md), on->name, arg);
 418     else
 419         get_legacy_evp_names(EVP_MD_name(md), NULL, arg);
 420 }
 421 #endif
 422
 423 /*-
 424  * Constructors / destructors
 425  * ==========================
 426  */
 427
 428 OSSL_NAMEMAP *ossl_namemap_stored(OSSL_LIB_CTX *libctx)
 429 {
 430 #ifndef FIPS_MODULE
 431     int nms;
 432 #endif
 433     OSSL_NAMEMAP *namemap =
 434         ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_NAMEMAP_INDEX,
 435                               &stored_namemap_method);
 436
 437     if (namemap == NULL)
 438         return NULL;
 439
 440 #ifndef FIPS_MODULE
 441     nms = ossl_namemap_empty(namemap);
 442     if (nms < 0) {
 443         /*
 444          * Could not get lock to make the count, so maybe internal objects
 445          * weren't added. This seems safest.
 446          */
 447         return NULL;
 448     }
 449     if (nms == 1) {
 450         /* Before pilfering, we make sure the legacy database is populated */
 451         OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
 452                             | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
 453
 454         OBJ_NAME_do_all(OBJ_NAME_TYPE_CIPHER_METH,
 455                         get_legacy_cipher_names, namemap);
 456         OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH,
 457                         get_legacy_md_names, namemap);
 458     }
 459 #endif
 460
 461     return namemap;
 462 }
 463
 464 OSSL_NAMEMAP *ossl_namemap_new(void)
 465 {
 466     OSSL_NAMEMAP *namemap;
 467
 468     if ((namemap = OPENSSL_zalloc(sizeof(*namemap))) != NULL
 469         && (namemap->lock = CRYPTO_THREAD_lock_new()) != NULL
 470         && (namemap->namenum =
 471             lh_NAMENUM_ENTRY_new(namenum_hash, namenum_cmp)) != NULL)
 472         return namemap;
 473
 474     ossl_namemap_free(namemap);
 475     return NULL;
 476 }
 477
 478 void ossl_namemap_free(OSSL_NAMEMAP *namemap)
 479 {
 480     if (namemap == NULL || namemap->stored)
 481         return;
 482
 483     lh_NAMENUM_ENTRY_doall(namemap->namenum, namenum_free);
 484     lh_NAMENUM_ENTRY_free(namemap->namenum);
 485
 486     CRYPTO_THREAD_lock_free(namemap->lock);
 487     OPENSSL_free(namemap);
 488 }