crypto/context.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 "crypto/cryptlib.h"
  11 #include <openssl/conf.h>
  12 #include "internal/thread_once.h"
  13 #include "internal/property.h"
  14 #include "internal/core.h"
  15
  16 struct ossl_lib_ctx_onfree_list_st {
  17     ossl_lib_ctx_onfree_fn *fn;
  18     struct ossl_lib_ctx_onfree_list_st *next;
  19 };
  20
  21 struct ossl_lib_ctx_st {
  22     CRYPTO_RWLOCK *lock;
  23     CRYPTO_EX_DATA data;
  24
  25     /*
  26      * For most data in the OSSL_LIB_CTX we just use ex_data to store it. But
  27      * that doesn't work for ex_data itself - so we store that directly.
  28      */
  29     OSSL_EX_DATA_GLOBAL global;
  30
  31     /* Map internal static indexes to dynamically created indexes */
  32     int dyn_indexes[OSSL_LIB_CTX_MAX_INDEXES];
  33
  34     /* Keep a separate lock for each index */
  35     CRYPTO_RWLOCK *index_locks[OSSL_LIB_CTX_MAX_INDEXES];
  36
  37     CRYPTO_RWLOCK *oncelock;
  38     int run_once_done[OSSL_LIB_CTX_MAX_RUN_ONCE];
  39     int run_once_ret[OSSL_LIB_CTX_MAX_RUN_ONCE];
  40     struct ossl_lib_ctx_onfree_list_st *onfreelist;
  41 };
  42
  43 int ossl_lib_ctx_write_lock(OSSL_LIB_CTX *ctx)
  44 {
  45     return CRYPTO_THREAD_write_lock(ossl_lib_ctx_get_concrete(ctx)->lock);
  46 }
  47
  48 int ossl_lib_ctx_read_lock(OSSL_LIB_CTX *ctx)
  49 {
  50     return CRYPTO_THREAD_read_lock(ossl_lib_ctx_get_concrete(ctx)->lock);
  51 }
  52
  53 int ossl_lib_ctx_unlock(OSSL_LIB_CTX *ctx)
  54 {
  55     return CRYPTO_THREAD_unlock(ossl_lib_ctx_get_concrete(ctx)->lock);
  56 }
  57
  58 static int context_init(OSSL_LIB_CTX *ctx)
  59 {
  60     size_t i;
  61     int exdata_done = 0;
  62
  63     ctx->lock = CRYPTO_THREAD_lock_new();
  64     if (ctx->lock == NULL)
  65         return 0;
  66
  67     ctx->oncelock = CRYPTO_THREAD_lock_new();
  68     if (ctx->oncelock == NULL)
  69         goto err;
  70
  71     for (i = 0; i < OSSL_LIB_CTX_MAX_INDEXES; i++) {
  72         ctx->index_locks[i] = CRYPTO_THREAD_lock_new();
  73         ctx->dyn_indexes[i] = -1;
  74         if (ctx->index_locks[i] == NULL)
  75             goto err;
  76     }
  77
  78     /* OSSL_LIB_CTX is built on top of ex_data so we initialise that directly */
  79     if (!ossl_do_ex_data_init(ctx))
  80         goto err;
  81     exdata_done = 1;
  82
  83     if (!ossl_crypto_new_ex_data_ex(ctx, CRYPTO_EX_INDEX_OSSL_LIB_CTX, NULL,
  84                                     &ctx->data)) {
  85         ossl_crypto_cleanup_all_ex_data_int(ctx);
  86         goto err;
  87     }
  88
  89     /* Everything depends on properties, so we also pre-initialise that */
  90     if (!ossl_property_parse_init(ctx))
  91         goto err;
  92
  93     return 1;
  94  err:
  95     if (exdata_done)
  96         ossl_crypto_cleanup_all_ex_data_int(ctx);
  97     CRYPTO_THREAD_lock_free(ctx->oncelock);
  98     CRYPTO_THREAD_lock_free(ctx->lock);
  99     ctx->lock = NULL;
 100     return 0;
 101 }
 102
 103 static int context_deinit(OSSL_LIB_CTX *ctx)
 104 {
 105     struct ossl_lib_ctx_onfree_list_st *tmp, *onfree;
 106     int i;
 107
 108     if (ctx == NULL)
 109         return 1;
 110
 111     ossl_ctx_thread_stop(ctx);
 112
 113     onfree = ctx->onfreelist;
 114     while (onfree != NULL) {
 115         onfree->fn(ctx);
 116         tmp = onfree;
 117         onfree = onfree->next;
 118         OPENSSL_free(tmp);
 119     }
 120     CRYPTO_free_ex_data(CRYPTO_EX_INDEX_OSSL_LIB_CTX, NULL, &ctx->data);
 121     ossl_crypto_cleanup_all_ex_data_int(ctx);
 122     for (i = 0; i < OSSL_LIB_CTX_MAX_INDEXES; i++)
 123         CRYPTO_THREAD_lock_free(ctx->index_locks[i]);
 124
 125     CRYPTO_THREAD_lock_free(ctx->oncelock);
 126     CRYPTO_THREAD_lock_free(ctx->lock);
 127     ctx->lock = NULL;
 128     return 1;
 129 }
 130
 131 #ifndef FIPS_MODULE
 132 /* The default default context */
 133 static OSSL_LIB_CTX default_context_int;
 134
 135 static CRYPTO_ONCE default_context_init = CRYPTO_ONCE_STATIC_INIT;
 136 static CRYPTO_THREAD_LOCAL default_context_thread_local;
 137
 138 DEFINE_RUN_ONCE_STATIC(default_context_do_init)
 139 {
 140     return CRYPTO_THREAD_init_local(&default_context_thread_local, NULL)
 141         && context_init(&default_context_int);
 142 }
 143
 144 void ossl_lib_ctx_default_deinit(void)
 145 {
 146     context_deinit(&default_context_int);
 147 }
 148
 149 static OSSL_LIB_CTX *get_thread_default_context(void)
 150 {
 151     if (!RUN_ONCE(&default_context_init, default_context_do_init))
 152         return NULL;
 153
 154     return CRYPTO_THREAD_get_local(&default_context_thread_local);
 155 }
 156
 157 static OSSL_LIB_CTX *get_default_context(void)
 158 {
 159     OSSL_LIB_CTX *current_defctx = get_thread_default_context();
 160
 161     if (current_defctx == NULL)
 162         current_defctx = &default_context_int;
 163     return current_defctx;
 164 }
 165
 166 static int set_default_context(OSSL_LIB_CTX *defctx)
 167 {
 168     if (defctx == &default_context_int)
 169         defctx = NULL;
 170
 171     return CRYPTO_THREAD_set_local(&default_context_thread_local, defctx);
 172 }
 173 #endif
 174
 175 OSSL_LIB_CTX *OSSL_LIB_CTX_new(void)
 176 {
 177     OSSL_LIB_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx));
 178
 179     if (ctx != NULL && !context_init(ctx)) {
 180         OSSL_LIB_CTX_free(ctx);
 181         ctx = NULL;
 182     }
 183     return ctx;
 184 }
 185
 186 #ifndef FIPS_MODULE
 187 int OSSL_LIB_CTX_load_config(OSSL_LIB_CTX *ctx, const char *config_file)
 188 {
 189     return CONF_modules_load_file_ex(ctx, config_file, NULL, 0) > 0;
 190 }
 191 #endif
 192
 193 void OSSL_LIB_CTX_free(OSSL_LIB_CTX *ctx)
 194 {
 195     if (ossl_lib_ctx_is_default(ctx))
 196         return;
 197
 198     context_deinit(ctx);
 199     OPENSSL_free(ctx);
 200 }
 201
 202 #ifndef FIPS_MODULE
 203 OSSL_LIB_CTX *OSSL_LIB_CTX_get0_global_default(void)
 204 {
 205     if (!RUN_ONCE(&default_context_init, default_context_do_init))
 206         return NULL;
 207
 208     return &default_context_int;
 209 }
 210
 211 OSSL_LIB_CTX *OSSL_LIB_CTX_set0_default(OSSL_LIB_CTX *libctx)
 212 {
 213     OSSL_LIB_CTX *current_defctx;
 214
 215     if ((current_defctx = get_default_context()) != NULL) {
 216         if (libctx != NULL)
 217             set_default_context(libctx);
 218         return current_defctx;
 219     }
 220
 221     return NULL;
 222 }
 223 #endif
 224
 225 OSSL_LIB_CTX *ossl_lib_ctx_get_concrete(OSSL_LIB_CTX *ctx)
 226 {
 227 #ifndef FIPS_MODULE
 228     if (ctx == NULL)
 229         return get_default_context();
 230 #endif
 231     return ctx;
 232 }
 233
 234 int ossl_lib_ctx_is_default(OSSL_LIB_CTX *ctx)
 235 {
 236 #ifndef FIPS_MODULE
 237     if (ctx == NULL || ctx == get_default_context())
 238         return 1;
 239 #endif
 240     return 0;
 241 }
 242
 243 int ossl_lib_ctx_is_global_default(OSSL_LIB_CTX *ctx)
 244 {
 245 #ifndef FIPS_MODULE
 246     if (ossl_lib_ctx_get_concrete(ctx) == &default_context_int)
 247         return 1;
 248 #endif
 249     return 0;
 250 }
 251
 252 static void ossl_lib_ctx_generic_new(void *parent_ign, void *ptr_ign,
 253                                      CRYPTO_EX_DATA *ad, int index,
 254                                      long argl_ign, void *argp)
 255 {
 256     const OSSL_LIB_CTX_METHOD *meth = argp;
 257     OSSL_LIB_CTX *ctx = ossl_crypto_ex_data_get_ossl_lib_ctx(ad);
 258     void *ptr = meth->new_func(ctx);
 259
 260     if (ptr != NULL) {
 261         if (!CRYPTO_THREAD_write_lock(ctx->lock))
 262             /*
 263              * Can't return something, so best to hope that something will
 264              * fail later. :(
 265              */
 266             return;
 267         CRYPTO_set_ex_data(ad, index, ptr);
 268         CRYPTO_THREAD_unlock(ctx->lock);
 269     }
 270 }
 271 static void ossl_lib_ctx_generic_free(void *parent_ign, void *ptr,
 272                                       CRYPTO_EX_DATA *ad, int index,
 273                                       long argl_ign, void *argp)
 274 {
 275     const OSSL_LIB_CTX_METHOD *meth = argp;
 276
 277     meth->free_func(ptr);
 278 }
 279
 280 /* Non-static so we can use it in context_internal_test */
 281 static int ossl_lib_ctx_init_index(OSSL_LIB_CTX *ctx, int static_index,
 282                                    const OSSL_LIB_CTX_METHOD *meth)
 283 {
 284     int idx;
 285
 286     ctx = ossl_lib_ctx_get_concrete(ctx);
 287     if (ctx == NULL)
 288         return 0;
 289
 290     idx = ossl_crypto_get_ex_new_index_ex(ctx, CRYPTO_EX_INDEX_OSSL_LIB_CTX, 0,
 291                                           (void *)meth,
 292                                           ossl_lib_ctx_generic_new,
 293                                           NULL, ossl_lib_ctx_generic_free);
 294     if (idx < 0)
 295         return 0;
 296
 297     ctx->dyn_indexes[static_index] = idx;
 298     return 1;
 299 }
 300
 301 void *ossl_lib_ctx_get_data(OSSL_LIB_CTX *ctx, int index,
 302                             const OSSL_LIB_CTX_METHOD *meth)
 303 {
 304     void *data = NULL;
 305     int dynidx;
 306
 307     ctx = ossl_lib_ctx_get_concrete(ctx);
 308     if (ctx == NULL)
 309         return NULL;
 310
 311     if (!CRYPTO_THREAD_read_lock(ctx->lock))
 312         return NULL;
 313     dynidx = ctx->dyn_indexes[index];
 314     CRYPTO_THREAD_unlock(ctx->lock);
 315
 316     if (dynidx != -1) {
 317         if (!CRYPTO_THREAD_read_lock(ctx->index_locks[index]))
 318             return NULL;
 319         if (!CRYPTO_THREAD_read_lock(ctx->lock)) {
 320             CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 321             return NULL;
 322         }
 323         data = CRYPTO_get_ex_data(&ctx->data, dynidx);
 324         CRYPTO_THREAD_unlock(ctx->lock);
 325         CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 326         return data;
 327     }
 328
 329     if (!CRYPTO_THREAD_write_lock(ctx->index_locks[index]))
 330         return NULL;
 331     if (!CRYPTO_THREAD_write_lock(ctx->lock)) {
 332         CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 333         return NULL;
 334     }
 335
 336     dynidx = ctx->dyn_indexes[index];
 337     if (dynidx != -1) {
 338         data = CRYPTO_get_ex_data(&ctx->data, dynidx);
 339         CRYPTO_THREAD_unlock(ctx->lock);
 340         CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 341         return data;
 342     }
 343
 344     if (!ossl_lib_ctx_init_index(ctx, index, meth)) {
 345         CRYPTO_THREAD_unlock(ctx->lock);
 346         CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 347         return NULL;
 348     }
 349
 350     CRYPTO_THREAD_unlock(ctx->lock);
 351
 352     /*
 353      * The alloc call ensures there's a value there. We release the ctx->lock
 354      * for this, because the allocation itself may recursively call
 355      * ossl_lib_ctx_get_data for other indexes (never this one). The allocation
 356      * will itself aquire the ctx->lock when it actually comes to store the
 357      * allocated data (see ossl_lib_ctx_generic_new() above). We call
 358      * ossl_crypto_alloc_ex_data_intern() here instead of CRYPTO_alloc_ex_data().
 359      * They do the same thing except that the latter calls CRYPTO_get_ex_data()
 360      * as well - which we must not do without holding the ctx->lock.
 361      */
 362     if (ossl_crypto_alloc_ex_data_intern(CRYPTO_EX_INDEX_OSSL_LIB_CTX, NULL,
 363                                          &ctx->data, ctx->dyn_indexes[index])) {
 364         if (!CRYPTO_THREAD_read_lock(ctx->lock))
 365             goto end;
 366         data = CRYPTO_get_ex_data(&ctx->data, ctx->dyn_indexes[index]);
 367         CRYPTO_THREAD_unlock(ctx->lock);
 368     }
 369
 370 end:
 371     CRYPTO_THREAD_unlock(ctx->index_locks[index]);
 372     return data;
 373 }
 374
 375 OSSL_EX_DATA_GLOBAL *ossl_lib_ctx_get_ex_data_global(OSSL_LIB_CTX *ctx)
 376 {
 377     ctx = ossl_lib_ctx_get_concrete(ctx);
 378     if (ctx == NULL)
 379         return NULL;
 380     return &ctx->global;
 381 }
 382
 383 int ossl_lib_ctx_run_once(OSSL_LIB_CTX *ctx, unsigned int idx,
 384                           ossl_lib_ctx_run_once_fn run_once_fn)
 385 {
 386     int done = 0, ret = 0;
 387
 388     ctx = ossl_lib_ctx_get_concrete(ctx);
 389     if (ctx == NULL)
 390         return 0;
 391
 392     if (!CRYPTO_THREAD_read_lock(ctx->oncelock))
 393         return 0;
 394     done = ctx->run_once_done[idx];
 395     if (done)
 396         ret = ctx->run_once_ret[idx];
 397     CRYPTO_THREAD_unlock(ctx->oncelock);
 398
 399     if (done)
 400         return ret;
 401
 402     if (!CRYPTO_THREAD_write_lock(ctx->oncelock))
 403         return 0;
 404     if (ctx->run_once_done[idx]) {
 405         ret = ctx->run_once_ret[idx];
 406         CRYPTO_THREAD_unlock(ctx->oncelock);
 407         return ret;
 408     }
 409
 410     ret = run_once_fn(ctx);
 411     ctx->run_once_done[idx] = 1;
 412     ctx->run_once_ret[idx] = ret;
 413     CRYPTO_THREAD_unlock(ctx->oncelock);
 414
 415     return ret;
 416 }
 417
 418 int ossl_lib_ctx_onfree(OSSL_LIB_CTX *ctx, ossl_lib_ctx_onfree_fn onfreefn)
 419 {
 420     struct ossl_lib_ctx_onfree_list_st *newonfree
 421         = OPENSSL_malloc(sizeof(*newonfree));
 422
 423     if (newonfree == NULL)
 424         return 0;
 425
 426     newonfree->fn = onfreefn;
 427     newonfree->next = ctx->onfreelist;
 428     ctx->onfreelist = newonfree;
 429
 430     return 1;
 431 }
 432
 433 const char *ossl_lib_ctx_get_descriptor(OSSL_LIB_CTX *libctx)
 434 {
 435 #ifdef FIPS_MODULE
 436     return "FIPS internal library context";
 437 #else
 438     if (ossl_lib_ctx_is_global_default(libctx))
 439         return "Global default library context";
 440     if (ossl_lib_ctx_is_default(libctx))
 441         return "Thread-local default library context";
 442     return "Non-default library context";
 443 #endif
 444 }