crypto/evp/evp_fetch.c

   1 /*
   2  * Copyright 2019 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 <stddef.h>
  11 #include <openssl/types.h>
  12 #include <openssl/evp.h>
  13 #include <openssl/core.h>
  14 #include "internal/cryptlib.h"
  15 #include "internal/thread_once.h"
  16 #include "internal/property.h"
  17 #include "internal/core.h"
  18 #include "internal/provider.h"
  19 #include "internal/namemap.h"
  20 #include "crypto/evp.h"    /* evp_local.h needs it */
  21 #include "evp_local.h"
  22
  23 #define NAME_SEPARATOR ':'
  24
  25 static void evp_method_store_free(void *vstore)
  26 {
  27     ossl_method_store_free(vstore);
  28 }
  29
  30 static void *evp_method_store_new(OPENSSL_CTX *ctx)
  31 {
  32     return ossl_method_store_new(ctx);
  33 }
  34
  35
  36 static const OPENSSL_CTX_METHOD evp_method_store_method = {
  37     evp_method_store_new,
  38     evp_method_store_free,
  39 };
  40
  41 /* Data to be passed through ossl_method_construct() */
  42 struct evp_method_data_st {
  43     OPENSSL_CTX *libctx;
  44     OSSL_METHOD_CONSTRUCT_METHOD *mcm;
  45     int operation_id;            /* For get_evp_method_from_store() */
  46     int name_id;                 /* For get_evp_method_from_store() */
  47     const char *names;           /* For get_evp_method_from_store() */
  48     const char *propquery;       /* For get_evp_method_from_store() */
  49     void *(*method_from_dispatch)(int name_id, const OSSL_DISPATCH *,
  50                                   OSSL_PROVIDER *);
  51     int (*refcnt_up_method)(void *method);
  52     void (*destruct_method)(void *method);
  53 };
  54
  55 #ifndef FIPS_MODE
  56 /* Creates an initial namemap with names found in the legacy method db */
  57 static void get_legacy_evp_names(const char *main_name, const char *alias,
  58                                  void *arg)
  59 {
  60     int main_id = ossl_namemap_add_name(arg, 0, main_name);
  61
  62     /*
  63      * We could check that the returned value is the same as main_id,
  64      * but since this is a void function, there's no sane way to report
  65      * the error.  The best we can do is trust ourselve to keep the legacy
  66      * method database conflict free.
  67      *
  68      * This registers any alias with the same number as the main name.
  69      * Should it be that the current |on| *has* the main name, this is
  70      * simply a no-op.
  71      */
  72     if (alias != NULL)
  73         (void)ossl_namemap_add_name(arg, main_id, alias);
  74 }
  75
  76 static void get_legacy_cipher_names(const OBJ_NAME *on, void *arg)
  77 {
  78     const EVP_CIPHER *cipher = (void *)OBJ_NAME_get(on->name, on->type);
  79
  80     get_legacy_evp_names(EVP_CIPHER_name(cipher), on->name, arg);
  81 }
  82
  83 static void get_legacy_md_names(const OBJ_NAME *on, void *arg)
  84 {
  85     const EVP_MD *md = (void *)OBJ_NAME_get(on->name, on->type);
  86     /* We don't want the pkey_type names, so we need some extra care */
  87     int snid, lnid;
  88
  89     snid = OBJ_sn2nid(on->name);
  90     lnid = OBJ_ln2nid(on->name);
  91     if (snid != EVP_MD_pkey_type(md) && lnid != EVP_MD_pkey_type(md))
  92         get_legacy_evp_names(EVP_MD_name(md), on->name, arg);
  93     else
  94         get_legacy_evp_names(EVP_MD_name(md), NULL, arg);
  95 }
  96 #endif
  97
  98 static OSSL_NAMEMAP *get_prepopulated_namemap(OPENSSL_CTX *libctx)
  99 {
 100     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 101
 102 #ifndef FIPS_MODE
 103     if (namemap != NULL && ossl_namemap_empty(namemap)) {
 104         /* Before pilfering, we make sure the legacy database is populated */
 105         OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
 106                             |OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
 107
 108         OBJ_NAME_do_all(OBJ_NAME_TYPE_CIPHER_METH,
 109                         get_legacy_cipher_names, namemap);
 110         OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH,
 111                         get_legacy_md_names, namemap);
 112     }
 113 #endif
 114
 115     return namemap;
 116 }
 117
 118 /*
 119  * Generic routines to fetch / create EVP methods with ossl_method_construct()
 120  */
 121 static void *alloc_tmp_evp_method_store(OPENSSL_CTX *ctx)
 122 {
 123     return ossl_method_store_new(ctx);
 124 }
 125
 126  static void dealloc_tmp_evp_method_store(void *store)
 127 {
 128     if (store != NULL)
 129         ossl_method_store_free(store);
 130 }
 131
 132 static OSSL_METHOD_STORE *get_evp_method_store(OPENSSL_CTX *libctx)
 133 {
 134     return openssl_ctx_get_data(libctx, OPENSSL_CTX_EVP_METHOD_STORE_INDEX,
 135                                 &evp_method_store_method);
 136 }
 137
 138 /*
 139  * To identity the method in the EVP method store, we mix the name identity
 140  * with the operation identity, with the assumption that we don't have more
 141  * than 2^24 names or more than 2^8 operation types.
 142  *
 143  * The resulting identity is a 32-bit integer, composed like this:
 144  *
 145  * +---------24 bits--------+-8 bits-+
 146  * |      name identity     | op id  |
 147  * +------------------------+--------+
 148  */
 149 static uint32_t evp_method_id(unsigned int operation_id, int name_id)
 150 {
 151     if (!ossl_assert(name_id < (1 << 24) || operation_id < (1 << 8))
 152         || !ossl_assert(name_id > 0 && operation_id > 0))
 153         return 0;
 154     return ((name_id << 8) & 0xFFFFFF00) | (operation_id & 0x000000FF);
 155 }
 156
 157 static void *get_evp_method_from_store(OPENSSL_CTX *libctx, void *store,
 158                                        void *data)
 159 {
 160     struct evp_method_data_st *methdata = data;
 161     void *method = NULL;
 162     int name_id;
 163     uint32_t meth_id;
 164
 165     /*
 166      * get_evp_method_from_store() is only called to try and get the method
 167      * that evp_generic_fetch() is asking for, and the operation id as well
 168      * as the name or name id are passed via methdata.
 169      */
 170     if ((name_id = methdata->name_id) == 0) {
 171         OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 172         const char *names = methdata->names;
 173         const char *q = strchr(names, NAME_SEPARATOR);
 174         size_t l = (q == NULL ? strlen(names) : (size_t)(q - names));
 175
 176         if (namemap == 0)
 177             return NULL;
 178         name_id = ossl_namemap_name2num_n(namemap, names, l);
 179     }
 180
 181     if (name_id == 0
 182         || (meth_id = evp_method_id(methdata->operation_id, name_id)) == 0)
 183         return NULL;
 184
 185     if (store == NULL
 186         && (store = get_evp_method_store(libctx)) == NULL)
 187         return NULL;
 188
 189     if (!ossl_method_store_fetch(store, meth_id, methdata->propquery,
 190                                  &method))
 191         return NULL;
 192     return method;
 193 }
 194
 195 static int put_evp_method_in_store(OPENSSL_CTX *libctx, void *store,
 196                                    void *method, const OSSL_PROVIDER *prov,
 197                                    int operation_id, const char *names,
 198                                    const char *propdef, void *data)
 199 {
 200     struct evp_method_data_st *methdata = data;
 201     OSSL_NAMEMAP *namemap;
 202     int name_id;
 203     uint32_t meth_id;
 204     size_t l = 0;
 205
 206     /*
 207      * put_evp_method_in_store() is only called with an EVP method that was
 208      * successfully created by construct_method() below, which means that
 209      * all the names should already be stored in the namemap with the same
 210      * numeric identity, so just use the first to get that identity.
 211      */
 212     if (names != NULL) {
 213         const char *q = strchr(names, NAME_SEPARATOR);
 214
 215         l = (q == NULL ? strlen(names) : (size_t)(q - names));
 216     }
 217
 218     if ((namemap = ossl_namemap_stored(libctx)) == NULL
 219         || (name_id = ossl_namemap_name2num_n(namemap, names, l)) == 0
 220         || (meth_id = evp_method_id(operation_id, name_id)) == 0)
 221         return 0;
 222
 223     if (store == NULL
 224         && (store = get_evp_method_store(libctx)) == NULL)
 225         return 0;
 226
 227     return ossl_method_store_add(store, prov, meth_id, propdef, method,
 228                                  methdata->refcnt_up_method,
 229                                  methdata->destruct_method);
 230 }
 231
 232 /*
 233  * The core fetching functionality passes the name of the implementation.
 234  * This function is responsible to getting an identity number for it.
 235  */
 236 static void *construct_evp_method(const char *names, const OSSL_DISPATCH *fns,
 237                                   OSSL_PROVIDER *prov, void *data)
 238 {
 239     /*
 240      * This function is only called if get_evp_method_from_store() returned
 241      * NULL, so it's safe to say that of all the spots to create a new
 242      * namemap entry, this is it.  Should the name already exist there, we
 243      * know that ossl_namemap_add_name() will return its corresponding
 244      * number.
 245      */
 246     struct evp_method_data_st *methdata = data;
 247     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 248     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 249     int name_id = ossl_namemap_add_names(namemap, 0, names, NAME_SEPARATOR);
 250
 251     if (name_id == 0)
 252         return NULL;
 253     return methdata->method_from_dispatch(name_id, fns, prov);
 254 }
 255
 256 static void destruct_evp_method(void *method, void *data)
 257 {
 258     struct evp_method_data_st *methdata = data;
 259
 260     methdata->destruct_method(method);
 261 }
 262
 263 static void *
 264 inner_evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 265                         int name_id, const char *name,
 266                         const char *properties,
 267                         void *(*new_method)(int name_id,
 268                                             const OSSL_DISPATCH *fns,
 269                                             OSSL_PROVIDER *prov),
 270                         int (*up_ref_method)(void *),
 271                         void (*free_method)(void *))
 272 {
 273     OSSL_METHOD_STORE *store = get_evp_method_store(libctx);
 274     OSSL_NAMEMAP *namemap = get_prepopulated_namemap(libctx);
 275     uint32_t meth_id = 0;
 276     void *method = NULL;
 277
 278     if (store == NULL || namemap == NULL)
 279         return NULL;
 280
 281     /*
 282      * If there's ever an operation_id == 0 passed, we have an internal
 283      * programming error.
 284      */
 285     if (!ossl_assert(operation_id > 0))
 286         return NULL;
 287
 288     /*
 289      * If we have been passed neither a name_id or a name, we have an
 290      * internal programming error.
 291      */
 292     if (!ossl_assert(name_id != 0 || name != NULL))
 293         return NULL;
 294
 295     /* If we haven't received a name id yet, try to get one for the name */
 296     if (name_id == 0)
 297         name_id = ossl_namemap_name2num(namemap, name);
 298
 299     /*
 300      * If we have a name id, calculate a method id with evp_method_id().
 301      *
 302      * evp_method_id returns 0 if we have too many operations (more than
 303      * about 2^8) or too many names (more than about 2^24).  In that case,
 304      * we can't create any new method.
 305      */
 306     if (name_id != 0 && (meth_id = evp_method_id(operation_id, name_id)) == 0)
 307         return NULL;
 308
 309     if (meth_id == 0
 310         || !ossl_method_store_cache_get(store, meth_id, properties, &method)) {
 311         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
 312             alloc_tmp_evp_method_store,
 313             dealloc_tmp_evp_method_store,
 314             get_evp_method_from_store,
 315             put_evp_method_in_store,
 316             construct_evp_method,
 317             destruct_evp_method
 318         };
 319         struct evp_method_data_st mcmdata;
 320
 321         mcmdata.mcm = &mcm;
 322         mcmdata.libctx = libctx;
 323         mcmdata.operation_id = operation_id;
 324         mcmdata.name_id = name_id;
 325         mcmdata.names = name;
 326         mcmdata.propquery = properties;
 327         mcmdata.method_from_dispatch = new_method;
 328         mcmdata.refcnt_up_method = up_ref_method;
 329         mcmdata.destruct_method = free_method;
 330         if ((method = ossl_method_construct(libctx, operation_id,
 331                                             0 /* !force_cache */,
 332                                             &mcm, &mcmdata)) != NULL) {
 333             /*
 334              * If construction did create a method for us, we know that
 335              * there is a correct name_id and meth_id, since those have
 336              * already been calculated in get_evp_method_from_store() and
 337              * put_evp_method_in_store() above.
 338              */
 339             if (name_id == 0)
 340                 name_id = ossl_namemap_name2num(namemap, name);
 341             meth_id = evp_method_id(operation_id, name_id);
 342             ossl_method_store_cache_set(store, meth_id, properties, method,
 343                                         up_ref_method, free_method);
 344         }
 345     }
 346
 347     return method;
 348 }
 349
 350 void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 351                         const char *name, const char *properties,
 352                         void *(*new_method)(int name_id,
 353                                             const OSSL_DISPATCH *fns,
 354                                             OSSL_PROVIDER *prov),
 355                         int (*up_ref_method)(void *),
 356                         void (*free_method)(void *))
 357 {
 358     return inner_evp_generic_fetch(libctx,
 359                                    operation_id, 0, name, properties,
 360                                    new_method, up_ref_method, free_method);
 361 }
 362
 363 /*
 364  * evp_generic_fetch_by_number() is special, and only returns methods for
 365  * already known names, i.e. it refuses to work if no name_id can be found
 366  * (it's considered an internal programming error).
 367  * This is meant to be used when one method needs to fetch an associated
 368  * other method.
 369  */
 370 void *evp_generic_fetch_by_number(OPENSSL_CTX *libctx, int operation_id,
 371                                   int name_id, const char *properties,
 372                                   void *(*new_method)(int name_id,
 373                                                       const OSSL_DISPATCH *fns,
 374                                                       OSSL_PROVIDER *prov),
 375                                   int (*up_ref_method)(void *),
 376                                   void (*free_method)(void *))
 377 {
 378     return inner_evp_generic_fetch(libctx,
 379                                    operation_id, name_id, NULL, properties,
 380                                    new_method, up_ref_method, free_method);
 381 }
 382
 383 int EVP_set_default_properties(OPENSSL_CTX *libctx, const char *propq)
 384 {
 385     OSSL_METHOD_STORE *store = get_evp_method_store(libctx);
 386
 387     if (store != NULL)
 388         return ossl_method_store_set_global_properties(store, propq);
 389     EVPerr(EVP_F_EVP_SET_DEFAULT_PROPERTIES, ERR_R_INTERNAL_ERROR);
 390     return 0;
 391 }
 392
 393 struct do_all_data_st {
 394     void (*user_fn)(void *method, void *arg);
 395     void *user_arg;
 396     void *(*new_method)(const int name_id, const OSSL_DISPATCH *fns,
 397                         OSSL_PROVIDER *prov);
 398     void (*free_method)(void *);
 399 };
 400
 401 static void do_one(OSSL_PROVIDER *provider, const OSSL_ALGORITHM *algo,
 402                    int no_store, void *vdata)
 403 {
 404     struct do_all_data_st *data = vdata;
 405     OPENSSL_CTX *libctx = ossl_provider_library_context(provider);
 406     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 407     int name_id = ossl_namemap_add_names(namemap, 0, algo->algorithm_names,
 408                                          NAME_SEPARATOR);
 409     void *method = NULL;
 410
 411     if (name_id != 0)
 412         method = data->new_method(name_id, algo->implementation, provider);
 413
 414     if (method != NULL) {
 415         data->user_fn(method, data->user_arg);
 416         data->free_method(method);
 417     }
 418 }
 419
 420 void evp_generic_do_all(OPENSSL_CTX *libctx, int operation_id,
 421                         void (*user_fn)(void *method, void *arg),
 422                         void *user_arg,
 423                         void *(*new_method)(int name_id,
 424                                             const OSSL_DISPATCH *fns,
 425                                             OSSL_PROVIDER *prov),
 426                         void (*free_method)(void *))
 427 {
 428     struct do_all_data_st data;
 429
 430     data.new_method = new_method;
 431     data.free_method = free_method;
 432     data.user_fn = user_fn;
 433     data.user_arg = user_arg;
 434     ossl_algorithm_do_all(libctx, operation_id, NULL, do_one, &data);
 435 }
 436
 437 const char *evp_first_name(OSSL_PROVIDER *prov, int name_id)
 438 {
 439     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 440     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 441
 442     return ossl_namemap_num2name(namemap, name_id, 0);
 443 }
 444
 445 int evp_is_a(OSSL_PROVIDER *prov, int number, const char *name)
 446 {
 447     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 448     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 449
 450     return ossl_namemap_name2num(namemap, name) == number;
 451 }
 452
 453 void evp_names_do_all(OSSL_PROVIDER *prov, int number,
 454                       void (*fn)(const char *name, void *data),
 455                       void *data)
 456 {
 457     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 458     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 459
 460     ossl_namemap_doall_names(namemap, number, fn, data);
 461 }