crypto/core_namemap.c

   1 /*
   2  * Copyright 2019-2020 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"      /* openssl_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 openssl_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     CRYPTO_THREAD_read_lock(namemap->lock);
 111     rv = namemap->max_number == 0;
 112     CRYPTO_THREAD_unlock(namemap->lock);
 113     return rv;
 114 #endif
 115 }
 116
 117 typedef struct doall_names_data_st {
 118     int number;
 119     const char **names;
 120     int found;
 121 } DOALL_NAMES_DATA;
 122
 123 static void do_name(const NAMENUM_ENTRY *namenum, DOALL_NAMES_DATA *data)
 124 {
 125     if (namenum->number == data->number)
 126         data->names[data->found++] = namenum->name;
 127 }
 128
 129 IMPLEMENT_LHASH_DOALL_ARG_CONST(NAMENUM_ENTRY, DOALL_NAMES_DATA);
 130
 131 /*
 132  * Call the callback for all names in the namemap with the given number.
 133  * A return value 1 means that the callback was called for all names. A
 134  * return value of 0 means that the callback was not called for any names.
 135  */
 136 int ossl_namemap_doall_names(const OSSL_NAMEMAP *namemap, int number,
 137                              void (*fn)(const char *name, void *data),
 138                              void *data)
 139 {
 140     DOALL_NAMES_DATA cbdata;
 141     size_t num_names;
 142     int i;
 143
 144     cbdata.number = number;
 145     cbdata.found = 0;
 146
 147     /*
 148      * We collect all the names first under a read lock. Subsequently we call
 149      * the user function, so that we're not holding the read lock when in user
 150      * code. This could lead to deadlocks.
 151      */
 152     CRYPTO_THREAD_read_lock(namemap->lock);
 153     num_names = lh_NAMENUM_ENTRY_num_items(namemap->namenum);
 154
 155     if (num_names == 0) {
 156         CRYPTO_THREAD_unlock(namemap->lock);
 157         return 0;
 158     }
 159     cbdata.names = OPENSSL_malloc(sizeof(*cbdata.names) * num_names);
 160     if (cbdata.names == NULL) {
 161         CRYPTO_THREAD_unlock(namemap->lock);
 162         return 0;
 163     }
 164     lh_NAMENUM_ENTRY_doall_DOALL_NAMES_DATA(namemap->namenum, do_name,
 165                                             &cbdata);
 166     CRYPTO_THREAD_unlock(namemap->lock);
 167
 168     for (i = 0; i < cbdata.found; i++)
 169         fn(cbdata.names[i], data);
 170
 171     OPENSSL_free(cbdata.names);
 172     return 1;
 173 }
 174
 175 static int namemap_name2num_n(const OSSL_NAMEMAP *namemap,
 176                               const char *name, size_t name_len)
 177 {
 178     NAMENUM_ENTRY *namenum_entry, namenum_tmpl;
 179
 180     if ((namenum_tmpl.name = OPENSSL_strndup(name, name_len)) == NULL)
 181         return 0;
 182     namenum_tmpl.number = 0;
 183     namenum_entry =
 184         lh_NAMENUM_ENTRY_retrieve(namemap->namenum, &namenum_tmpl);
 185     OPENSSL_free(namenum_tmpl.name);
 186     return namenum_entry != NULL ? namenum_entry->number : 0;
 187 }
 188
 189 int ossl_namemap_name2num_n(const OSSL_NAMEMAP *namemap,
 190                             const char *name, size_t name_len)
 191 {
 192     int number;
 193
 194 #ifndef FIPS_MODULE
 195     if (namemap == NULL)
 196         namemap = ossl_namemap_stored(NULL);
 197 #endif
 198
 199     if (namemap == NULL)
 200         return 0;
 201
 202     CRYPTO_THREAD_read_lock(namemap->lock);
 203     number = namemap_name2num_n(namemap, name, name_len);
 204     CRYPTO_THREAD_unlock(namemap->lock);
 205
 206     return number;
 207 }
 208
 209 int ossl_namemap_name2num(const OSSL_NAMEMAP *namemap, const char *name)
 210 {
 211     if (name == NULL)
 212         return 0;
 213
 214     return ossl_namemap_name2num_n(namemap, name, strlen(name));
 215 }
 216
 217 struct num2name_data_st {
 218     size_t idx;                  /* Countdown */
 219     const char *name;            /* Result */
 220 };
 221
 222 static void do_num2name(const char *name, void *vdata)
 223 {
 224     struct num2name_data_st *data = vdata;
 225
 226     if (data->idx > 0)
 227         data->idx--;
 228     else if (data->name == NULL)
 229         data->name = name;
 230 }
 231
 232 const char *ossl_namemap_num2name(const OSSL_NAMEMAP *namemap, int number,
 233                                   size_t idx)
 234 {
 235     struct num2name_data_st data;
 236
 237     data.idx = idx;
 238     data.name = NULL;
 239     if (!ossl_namemap_doall_names(namemap, number, do_num2name, &data))
 240         return NULL;
 241     return data.name;
 242 }
 243
 244 static int namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
 245                               const char *name, size_t name_len)
 246 {
 247     NAMENUM_ENTRY *namenum = NULL;
 248     int tmp_number;
 249
 250     /* If it already exists, we don't add it */
 251     if ((tmp_number = namemap_name2num_n(namemap, name, name_len)) != 0)
 252         return tmp_number;
 253
 254     if ((namenum = OPENSSL_zalloc(sizeof(*namenum))) == NULL
 255         || (namenum->name = OPENSSL_strndup(name, name_len)) == NULL)
 256         goto err;
 257
 258     namenum->number =
 259         number != 0 ? number : 1 + tsan_counter(&namemap->max_number);
 260     (void)lh_NAMENUM_ENTRY_insert(namemap->namenum, namenum);
 261
 262     if (lh_NAMENUM_ENTRY_error(namemap->namenum))
 263         goto err;
 264     return namenum->number;
 265
 266  err:
 267     namenum_free(namenum);
 268     return 0;
 269 }
 270
 271 int ossl_namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
 272                             const char *name, size_t name_len)
 273 {
 274     int tmp_number;
 275
 276 #ifndef FIPS_MODULE
 277     if (namemap == NULL)
 278         namemap = ossl_namemap_stored(NULL);
 279 #endif
 280
 281     if (name == NULL || name_len == 0 || namemap == NULL)
 282         return 0;
 283
 284     CRYPTO_THREAD_write_lock(namemap->lock);
 285     tmp_number = namemap_add_name_n(namemap, number, name, name_len);
 286     CRYPTO_THREAD_unlock(namemap->lock);
 287     return tmp_number;
 288 }
 289
 290 int ossl_namemap_add_name(OSSL_NAMEMAP *namemap, int number, const char *name)
 291 {
 292     if (name == NULL)
 293         return 0;
 294
 295     return ossl_namemap_add_name_n(namemap, number, name, strlen(name));
 296 }
 297
 298 int ossl_namemap_add_names(OSSL_NAMEMAP *namemap, int number,
 299                            const char *names, const char separator)
 300 {
 301     const char *p, *q;
 302     size_t l;
 303
 304     /* Check that we have a namemap */
 305     if (!ossl_assert(namemap != NULL)) {
 306         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
 307         return 0;
 308     }
 309
 310     CRYPTO_THREAD_write_lock(namemap->lock);
 311     /*
 312      * Check that no name is an empty string, and that all names have at
 313      * most one numeric identity together.
 314      */
 315     for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
 316         int this_number;
 317
 318         if ((q = strchr(p, separator)) == NULL)
 319             l = strlen(p);       /* offset to \0 */
 320         else
 321             l = q - p;           /* offset to the next separator */
 322
 323         this_number = namemap_name2num_n(namemap, p, l);
 324
 325         if (*p == '\0' || *p == separator) {
 326             ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_BAD_ALGORITHM_NAME);
 327             goto err;
 328         }
 329         if (number == 0) {
 330             number = this_number;
 331         } else if (this_number != 0 && this_number != number) {
 332             ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_CONFLICTING_NAMES,
 333                            "\"%.*s\" has an existing different identity %d (from \"%s\")",
 334                            l, p, this_number, names);
 335             goto err;
 336         }
 337     }
 338
 339     /* Now that we have checked, register all names */
 340     for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
 341         int this_number;
 342
 343         if ((q = strchr(p, separator)) == NULL)
 344             l = strlen(p);       /* offset to \0 */
 345         else
 346             l = q - p;           /* offset to the next separator */
 347
 348         this_number = namemap_add_name_n(namemap, number, p, l);
 349         if (number == 0) {
 350             number = this_number;
 351         } else if (this_number != number) {
 352             ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR,
 353                            "Got number %d when expecting %d",
 354                            this_number, number);
 355             goto err;
 356         }
 357     }
 358
 359     CRYPTO_THREAD_unlock(namemap->lock);
 360     return number;
 361
 362  err:
 363     CRYPTO_THREAD_unlock(namemap->lock);
 364     return 0;
 365 }
 366
 367 /*-
 368  * Pre-population
 369  * ==============
 370  */
 371
 372 #ifndef FIPS_MODULE
 373 #include <openssl/evp.h>
 374
 375 /* Creates an initial namemap with names found in the legacy method db */
 376 static void get_legacy_evp_names(const char *main_name, const char *alias,
 377                                  void *arg)
 378 {
 379     int main_id = ossl_namemap_add_name(arg, 0, main_name);
 380
 381     /*
 382      * We could check that the returned value is the same as main_id,
 383      * but since this is a void function, there's no sane way to report
 384      * the error.  The best we can do is trust ourselve to keep the legacy
 385      * method database conflict free.
 386      *
 387      * This registers any alias with the same number as the main name.
 388      * Should it be that the current |on| *has* the main name, this is
 389      * simply a no-op.
 390      */
 391     if (alias != NULL) {
 392         (void)ossl_namemap_add_name(arg, main_id, alias);
 393     }
 394 }
 395
 396 static void get_legacy_cipher_names(const OBJ_NAME *on, void *arg)
 397 {
 398     const EVP_CIPHER *cipher = (void *)OBJ_NAME_get(on->name, on->type);
 399
 400     get_legacy_evp_names(EVP_CIPHER_name(cipher), on->name, arg);
 401 }
 402
 403 static void get_legacy_md_names(const OBJ_NAME *on, void *arg)
 404 {
 405     const EVP_MD *md = (void *)OBJ_NAME_get(on->name, on->type);
 406     /* We don't want the pkey_type names, so we need some extra care */
 407     int snid, lnid;
 408
 409     snid = OBJ_sn2nid(on->name);
 410     lnid = OBJ_ln2nid(on->name);
 411     if (snid != EVP_MD_pkey_type(md) && lnid != EVP_MD_pkey_type(md))
 412         get_legacy_evp_names(EVP_MD_name(md), on->name, arg);
 413     else
 414         get_legacy_evp_names(EVP_MD_name(md), NULL, arg);
 415 }
 416 #endif
 417
 418 /*-
 419  * Constructors / destructors
 420  * ==========================
 421  */
 422
 423 OSSL_NAMEMAP *ossl_namemap_stored(OSSL_LIB_CTX *libctx)
 424 {
 425     OSSL_NAMEMAP *namemap =
 426         ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_NAMEMAP_INDEX,
 427                               &stored_namemap_method);
 428
 429 #ifndef FIPS_MODULE
 430     if (namemap != NULL && ossl_namemap_empty(namemap)) {
 431         /* Before pilfering, we make sure the legacy database is populated */
 432         OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
 433                             | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
 434
 435         OBJ_NAME_do_all(OBJ_NAME_TYPE_CIPHER_METH,
 436                         get_legacy_cipher_names, namemap);
 437         OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH,
 438                         get_legacy_md_names, namemap);
 439     }
 440 #endif
 441
 442     return namemap;
 443 }
 444
 445 OSSL_NAMEMAP *ossl_namemap_new(void)
 446 {
 447     OSSL_NAMEMAP *namemap;
 448
 449     if ((namemap = OPENSSL_zalloc(sizeof(*namemap))) != NULL
 450         && (namemap->lock = CRYPTO_THREAD_lock_new()) != NULL
 451         && (namemap->namenum =
 452             lh_NAMENUM_ENTRY_new(namenum_hash, namenum_cmp)) != NULL)
 453         return namemap;
 454
 455     ossl_namemap_free(namemap);
 456     return NULL;
 457 }
 458
 459 void ossl_namemap_free(OSSL_NAMEMAP *namemap)
 460 {
 461     if (namemap == NULL || namemap->stored)
 462         return;
 463
 464     lh_NAMENUM_ENTRY_doall(namemap->namenum, namenum_free);
 465     lh_NAMENUM_ENTRY_free(namemap->namenum);
 466
 467     CRYPTO_THREAD_lock_free(namemap->lock);
 468     OPENSSL_free(namemap);
 469 }