crypto/core_fetch.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 <stddef.h>
  11
  12 #include <openssl/core.h>
  13 #include "internal/cryptlib.h"
  14 #include "internal/core.h"
  15 #include "internal/property.h"
  16 #include "internal/provider.h"
  17
  18 struct construct_data_st {
  19     OPENSSL_CTX *libctx;
  20     OSSL_METHOD_STORE *store;
  21     int operation_id;
  22     int force_store;
  23     OSSL_METHOD_CONSTRUCT_METHOD *mcm;
  24     void *mcm_data;
  25 };
  26
  27 static int ossl_method_construct_precondition(OSSL_PROVIDER *provider,
  28                                               int operation_id, void *cbdata,
  29                                               int *result)
  30 {
  31     if (!ossl_assert(result != NULL)) {
  32         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
  33         return 0;
  34     }
  35
  36     if (!ossl_provider_test_operation_bit(provider, operation_id, result))
  37         return 0;
  38
  39     /*
  40      * The result we get tells if methods have already been constructed.
  41      * However, we want to tell whether construction should happen (true)
  42      * or not (false), which is the opposite of what we got.
  43      */
  44     *result = !*result;
  45
  46     return 1;
  47 }
  48
  49 static int ossl_method_construct_postcondition(OSSL_PROVIDER *provider,
  50                                                int operation_id, int no_store,
  51                                                void *cbdata, int *result)
  52 {
  53     if (!ossl_assert(result != NULL)) {
  54         ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
  55         return 0;
  56     }
  57
  58     *result = 1;
  59     return no_store != 0
  60         || ossl_provider_set_operation_bit(provider, operation_id);
  61 }
  62
  63 static void ossl_method_construct_this(OSSL_PROVIDER *provider,
  64                                        const OSSL_ALGORITHM *algo,
  65                                        int no_store, void *cbdata)
  66 {
  67     struct construct_data_st *data = cbdata;
  68     void *method = NULL;
  69
  70     if ((method = data->mcm->construct(algo, provider, data->mcm_data))
  71         == NULL)
  72         return;
  73
  74     /*
  75      * Note regarding putting the method in stores:
  76      *
  77      * we don't need to care if it actually got in or not here.
  78      * If it didn't get in, it will simply not be available when
  79      * ossl_method_construct() tries to get it from the store.
  80      *
  81      * It is *expected* that the put function increments the refcnt
  82      * of the passed method.
  83      */
  84
  85     if (data->force_store || !no_store) {
  86         /*
  87          * If we haven't been told not to store,
  88          * add to the global store
  89          */
  90         data->mcm->put(data->libctx, NULL, method, provider,
  91                        data->operation_id, algo->algorithm_names,
  92                        algo->property_definition, data->mcm_data);
  93     }
  94
  95     data->mcm->put(data->libctx, data->store, method, provider,
  96                    data->operation_id, algo->algorithm_names,
  97                    algo->property_definition, data->mcm_data);
  98
  99     /* refcnt-- because we're dropping the reference */
 100     data->mcm->destruct(method, data->mcm_data);
 101 }
 102
 103 void *ossl_method_construct(OPENSSL_CTX *libctx, int operation_id,
 104                             int force_store,
 105                             OSSL_METHOD_CONSTRUCT_METHOD *mcm, void *mcm_data)
 106 {
 107     void *method = NULL;
 108
 109     if ((method = mcm->get(libctx, NULL, mcm_data)) == NULL) {
 110         struct construct_data_st cbdata;
 111
 112         /*
 113          * We have a temporary store to be able to easily search among new
 114          * items, or items that should find themselves in the global store.
 115          */
 116         if ((cbdata.store = mcm->alloc_tmp_store(libctx)) == NULL)
 117             goto fin;
 118
 119         cbdata.libctx = libctx;
 120         cbdata.operation_id = operation_id;
 121         cbdata.force_store = force_store;
 122         cbdata.mcm = mcm;
 123         cbdata.mcm_data = mcm_data;
 124         ossl_algorithm_do_all(libctx, operation_id, NULL,
 125                               ossl_method_construct_precondition,
 126                               ossl_method_construct_this,
 127                               ossl_method_construct_postcondition,
 128                               &cbdata);
 129
 130         method = mcm->get(libctx, cbdata.store, mcm_data);
 131         mcm->dealloc_tmp_store(cbdata.store);
 132     }
 133
 134  fin:
 135     return method;
 136 }