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/ossl_typ.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 "internal/evp_int.h"    /* evp_locl.h needs it */
  21 #include "evp_locl.h"
  22
  23 static void default_method_store_free(void *vstore)
  24 {
  25     ossl_method_store_free(vstore);
  26 }
  27
  28 static void *default_method_store_new(OPENSSL_CTX *ctx)
  29 {
  30     return ossl_method_store_new(ctx);
  31 }
  32
  33
  34 static const OPENSSL_CTX_METHOD default_method_store_method = {
  35     default_method_store_new,
  36     default_method_store_free,
  37 };
  38
  39 /* Data to be passed through ossl_method_construct() */
  40 struct method_data_st {
  41     OPENSSL_CTX *libctx;
  42     OSSL_METHOD_CONSTRUCT_METHOD *mcm;
  43     int operation_id;            /* For get_method_from_store() */
  44     int name_id;                 /* For get_method_from_store() */
  45     const char *name;            /* For get_method_from_store() */
  46     const char *propquery;       /* For get_method_from_store() */
  47     void *(*method_from_dispatch)(int name_id, const OSSL_DISPATCH *,
  48                                   OSSL_PROVIDER *, void *);
  49     void *method_data;
  50     int (*refcnt_up_method)(void *method);
  51     void (*destruct_method)(void *method);
  52 };
  53
  54 /*
  55  * Generic routines to fetch / create EVP methods with ossl_method_construct()
  56  */
  57 static void *alloc_tmp_method_store(OPENSSL_CTX *ctx)
  58 {
  59     return ossl_method_store_new(ctx);
  60 }
  61
  62  static void dealloc_tmp_method_store(void *store)
  63 {
  64     if (store != NULL)
  65         ossl_method_store_free(store);
  66 }
  67
  68 static OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
  69 {
  70     return openssl_ctx_get_data(libctx, OPENSSL_CTX_DEFAULT_METHOD_STORE_INDEX,
  71                                 &default_method_store_method);
  72 }
  73
  74 /*
  75  * To identity the method in the method store, we mix the name identity
  76  * with the operation identity, with the assumption that we don't have
  77  * more than 2^24 names or more than 2^8 operation types.
  78  *
  79  * The resulting identity is a 32-bit integer, composed like this:
  80  *
  81  * +---------24 bits--------+-8 bits-+
  82  * |      name identity     | op id  |
  83  * +------------------------+--------+
  84  */
  85 static uint32_t method_id(unsigned int operation_id, int name_id)
  86 {
  87     if (!ossl_assert(name_id < (1 << 24) || operation_id < (1 << 8))
  88         || !ossl_assert(name_id > 0 && operation_id > 0))
  89         return 0;
  90     return ((name_id << 8) & 0xFFFFFF00) | (operation_id & 0x000000FF);
  91 }
  92
  93 static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
  94                                    void *data)
  95 {
  96     struct method_data_st *methdata = data;
  97     void *method = NULL;
  98     int name_id;
  99     uint32_t meth_id;
 100
 101     /*
 102      * get_method_from_store() is only called to try and get the method
 103      * that evp_generic_fetch() is asking for, and the operation id as
 104      * well as the name or name id are passed via methdata.
 105      */
 106     if ((name_id = methdata->name_id) == 0) {
 107         OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 108
 109         if (namemap == 0)
 110             return NULL;
 111         name_id = ossl_namemap_name2num(namemap, methdata->name);
 112     }
 113
 114     if (name_id == 0
 115         || (meth_id = method_id(methdata->operation_id, name_id)) == 0)
 116         return NULL;
 117
 118     if (store == NULL
 119         && (store = get_default_method_store(libctx)) == NULL)
 120         return NULL;
 121
 122     (void)ossl_method_store_fetch(store, meth_id, methdata->propquery,
 123                                   &method);
 124
 125     if (method != NULL
 126         && !methdata->refcnt_up_method(method)) {
 127         method = NULL;
 128     }
 129     return method;
 130 }
 131
 132 static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
 133                                void *method, const OSSL_PROVIDER *prov,
 134                                int operation_id, const char *name,
 135                                const char *propdef, void *data)
 136 {
 137     struct method_data_st *methdata = data;
 138     OSSL_NAMEMAP *namemap;
 139     int name_id;
 140     uint32_t meth_id;
 141
 142     /*
 143      * put_method_in_store() is only called with a method that was
 144      * successfully created by construct_method() below, which means
 145      * the name should already be stored in the namemap, so just use it.
 146      */
 147     if ((namemap = ossl_namemap_stored(libctx)) == NULL
 148         || (name_id = ossl_namemap_name2num(namemap, name)) == 0
 149         || (meth_id = method_id(operation_id, name_id)) == 0)
 150         return 0;
 151
 152     if (store == NULL
 153         && (store = get_default_method_store(libctx)) == NULL)
 154         return 0;
 155
 156     return ossl_method_store_add(store, prov, meth_id, propdef, method,
 157                                  methdata->refcnt_up_method,
 158                                  methdata->destruct_method);
 159 }
 160
 161 /*
 162  * The core fetching functionality passes the name of the implementation.
 163  * This function is responsible to getting an identity number for it.
 164  */
 165 static void *construct_method(const char *name, const OSSL_DISPATCH *fns,
 166                               OSSL_PROVIDER *prov, void *data)
 167 {
 168     /*
 169      * This function is only called if get_method_from_store() returned
 170      * NULL, so it's safe to say that of all the spots to create a new
 171      * namemap entry, this is it.  Should the name already exist there, we
 172      * know that ossl_namemap_add() will return its corresponding number.
 173      *
 174      * TODO(3.0): If this function gets an array of names instead of just
 175      * one, we need to check through all the names to see if at least one
 176      * of them has an associated number, and use that.  If several names
 177      * have associated numbers that differ from each other, it's an error.
 178      */
 179     struct method_data_st *methdata = data;
 180     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 181     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 182     int name_id = ossl_namemap_add(namemap, 0, name);
 183
 184     return methdata->method_from_dispatch(name_id, fns, prov,
 185                                           methdata->method_data);
 186 }
 187
 188 static void destruct_method(void *method, void *data)
 189 {
 190     struct method_data_st *methdata = data;
 191
 192     methdata->destruct_method(method);
 193 }
 194
 195 static void *inner_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 196                                  int name_id, const char *name,
 197                                  const char *properties,
 198                                  void *(*new_method)(int name_id,
 199                                                      const OSSL_DISPATCH *fns,
 200                                                      OSSL_PROVIDER *prov,
 201                                                      void *method_data),
 202                                  void *method_data,
 203                                  int (*up_ref_method)(void *),
 204                                  void (*free_method)(void *))
 205 {
 206     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 207     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 208     uint32_t meth_id = 0;
 209     void *method = NULL;
 210
 211     if (store == NULL || namemap == NULL)
 212         return NULL;
 213
 214     /*
 215      * If there's ever an operation_id == 0 passed, we have an internal
 216      * programming error.
 217      */
 218     if (!ossl_assert(operation_id > 0))
 219         return NULL;
 220
 221     /*
 222      * If we have been passed neither a name_id or a name, we have an
 223      * internal programming error.
 224      */
 225     if (!ossl_assert(name_id != 0 || name != NULL))
 226         return NULL;
 227
 228     /* If we haven't received a name id yet, try to get one for the name */
 229     if (name_id == 0)
 230         name_id = ossl_namemap_name2num(namemap, name);
 231
 232     /*
 233      * If we have a name id, calculate a method id with method_id().
 234      *
 235      * method_id returns 0 if we have too many operations (more than
 236      * about 2^8) or too many names (more than about 2^24).  In that
 237      * case, we can't create any new method.
 238      */
 239     if (name_id != 0 && (meth_id = method_id(operation_id, name_id)) == 0)
 240         return NULL;
 241
 242     if (meth_id == 0
 243         || !ossl_method_store_cache_get(store, meth_id, properties, &method)) {
 244         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
 245             alloc_tmp_method_store,
 246             dealloc_tmp_method_store,
 247             get_method_from_store,
 248             put_method_in_store,
 249             construct_method,
 250             destruct_method
 251         };
 252         struct method_data_st mcmdata;
 253
 254         mcmdata.mcm = &mcm;
 255         mcmdata.libctx = libctx;
 256         mcmdata.operation_id = operation_id;
 257         mcmdata.name_id = name_id;
 258         mcmdata.name = name;
 259         mcmdata.propquery = properties;
 260         mcmdata.method_from_dispatch = new_method;
 261         mcmdata.destruct_method = free_method;
 262         mcmdata.refcnt_up_method = up_ref_method;
 263         mcmdata.destruct_method = free_method;
 264         mcmdata.method_data = method_data;
 265         if ((method = ossl_method_construct(libctx, operation_id,
 266                                             0 /* !force_cache */,
 267                                             &mcm, &mcmdata)) != NULL) {
 268             /*
 269              * If construction did create a method for us, we know that
 270              * there is a correct name_id and methodid, since those have
 271              * already been calculated in get_method_from_store() and
 272              * put_method_in_store() above.
 273              */
 274             if (name_id == 0)
 275                 name_id = ossl_namemap_name2num(namemap, name);
 276             meth_id = method_id(operation_id, name_id);
 277             ossl_method_store_cache_set(store, meth_id, properties, method);
 278         }
 279     } else {
 280         up_ref_method(method);
 281     }
 282
 283     return method;
 284 }
 285
 286 void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 287                         const char *name, const char *properties,
 288                         void *(*new_method)(int name_id,
 289                                             const OSSL_DISPATCH *fns,
 290                                             OSSL_PROVIDER *prov,
 291                                             void *method_data),
 292                         void *method_data,
 293                         int (*up_ref_method)(void *),
 294                         void (*free_method)(void *))
 295 {
 296     return inner_generic_fetch(libctx,
 297                                operation_id, 0, name, properties,
 298                                new_method, method_data,
 299                                up_ref_method, free_method);
 300 }
 301
 302 /*
 303  * evp_generic_fetch_by_number() is special, and only returns methods for
 304  * already known names, i.e. it refuses to work if no name_id can be found
 305  * (it's considered an internal programming error).
 306  * This is meant to be used when one method needs to fetch an associated
 307  * other method.
 308  */
 309 void *evp_generic_fetch_by_number(OPENSSL_CTX *libctx, int operation_id,
 310                                   int name_id, const char *properties,
 311                                   void *(*new_method)(int name_id,
 312                                                       const OSSL_DISPATCH *fns,
 313                                                       OSSL_PROVIDER *prov,
 314                                                       void *method_data),
 315                                   void *method_data,
 316                                   int (*up_ref_method)(void *),
 317                                   void (*free_method)(void *))
 318 {
 319     return inner_generic_fetch(libctx,
 320                                operation_id, name_id, NULL, properties,
 321                                new_method, method_data,
 322                                up_ref_method, free_method);
 323 }
 324
 325 int EVP_set_default_properties(OPENSSL_CTX *libctx, const char *propq)
 326 {
 327     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 328
 329     if (store != NULL)
 330         return ossl_method_store_set_global_properties(store, propq);
 331     EVPerr(EVP_F_EVP_SET_DEFAULT_PROPERTIES, ERR_R_INTERNAL_ERROR);
 332     return 0;
 333 }
 334
 335 struct do_all_data_st {
 336     void (*user_fn)(void *method, void *arg);
 337     void *user_arg;
 338     void *(*new_method)(const int name_id, const OSSL_DISPATCH *fns,
 339                         OSSL_PROVIDER *prov, void *method_data);
 340     void (*free_method)(void *);
 341 };
 342
 343 static void do_one(OSSL_PROVIDER *provider, const OSSL_ALGORITHM *algo,
 344                    int no_store, void *vdata)
 345 {
 346     struct do_all_data_st *data = vdata;
 347     OPENSSL_CTX *libctx = ossl_provider_library_context(provider);
 348     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 349     int name_id = ossl_namemap_add(namemap, 0, algo->algorithm_name);
 350     void *method = NULL;
 351
 352     if (name_id != 0)
 353         method = data->new_method(name_id, algo->implementation, provider,
 354                                   NULL);
 355
 356     if (method != NULL) {
 357         data->user_fn(method, data->user_arg);
 358         data->free_method(method);
 359     }
 360 }
 361
 362 void evp_generic_do_all(OPENSSL_CTX *libctx, int operation_id,
 363                         void (*user_fn)(void *method, void *arg),
 364                         void *user_arg,
 365                         void *(*new_method)(int name_id,
 366                                             const OSSL_DISPATCH *fns,
 367                                             OSSL_PROVIDER *prov,
 368                                             void *method_data),
 369                         void *method_data,
 370                         void (*free_method)(void *))
 371 {
 372     struct do_all_data_st data;
 373
 374     data.new_method = new_method;
 375     data.free_method = free_method;
 376     data.user_fn = user_fn;
 377     data.user_arg = user_arg;
 378     ossl_algorithm_do_all(libctx, operation_id, method_data, do_one, &data);
 379 }
 380
 381 const char *evp_first_name(OSSL_PROVIDER *prov, int name_id)
 382 {
 383     OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
 384     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 385
 386     return ossl_namemap_num2name(namemap, name_id, 0);
 387 }