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/asn1_int.h"
  17 #include "internal/property.h"
  18 #include "internal/core.h"
  19 #include "internal/evp_int.h"    /* evp_locl.h needs it */
  20 #include "evp_locl.h"
  21
  22 /* The OpenSSL library context index for the default method store */
  23 static int default_method_store_index = -1;
  24
  25 static void default_method_store_free(void *vstore)
  26 {
  27     ossl_method_store_free(vstore);
  28 }
  29
  30 static void *default_method_store_new(void)
  31 {
  32     return ossl_method_store_new();
  33 }
  34
  35
  36 static const OPENSSL_CTX_METHOD default_method_store_method = {
  37     default_method_store_new,
  38     default_method_store_free,
  39 };
  40
  41 static int default_method_store_init(void)
  42 {
  43     default_method_store_index =
  44         openssl_ctx_new_index(&default_method_store_method);
  45
  46     return default_method_store_index != -1;
  47 }
  48
  49 static CRYPTO_ONCE default_method_store_init_flag = CRYPTO_ONCE_STATIC_INIT;
  50 DEFINE_RUN_ONCE_STATIC(do_default_method_store_init)
  51 {
  52     return OPENSSL_init_crypto(0, NULL)
  53         && default_method_store_init();
  54 }
  55
  56 /* Data to be passed through ossl_method_construct() */
  57 struct method_data_st {
  58     const char *name;
  59     int nid;
  60     OSSL_METHOD_CONSTRUCT_METHOD *mcm;
  61     void *(*method_from_dispatch)(int nid, const OSSL_DISPATCH *,
  62                                   OSSL_PROVIDER *);
  63     int (*refcnt_up_method)(void *method);
  64     void (*destruct_method)(void *method);
  65 };
  66
  67 /*
  68  * Generic routines to fetch / create EVP methods with ossl_method_construct()
  69  */
  70 static void *alloc_tmp_method_store(void)
  71 {
  72     return ossl_method_store_new();
  73 }
  74
  75  static void dealloc_tmp_method_store(void *store)
  76 {
  77     if (store != NULL)
  78         ossl_method_store_free(store);
  79 }
  80
  81 static
  82 struct OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
  83 {
  84     if (!RUN_ONCE(&default_method_store_init_flag,
  85                   do_default_method_store_init))
  86         return NULL;
  87     return openssl_ctx_get_data(libctx, default_method_store_index);
  88 }
  89
  90 static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
  91                                    const char *propquery, void *data)
  92 {
  93     struct method_data_st *methdata = data;
  94     void *method = NULL;
  95
  96     if (store == NULL
  97         && (store = get_default_method_store(libctx)) == NULL)
  98         return NULL;
  99
 100     (void)ossl_method_store_fetch(store, methdata->nid, propquery, &method);
 101
 102     if (method != NULL
 103         && !methdata->refcnt_up_method(method)) {
 104         method = NULL;
 105     }
 106     return method;
 107 }
 108
 109 static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
 110                                const char *propdef, void *method,
 111                                void *data)
 112 {
 113     struct method_data_st *methdata = data;
 114
 115     if (store == NULL
 116         && (store = get_default_method_store(libctx)) == NULL)
 117         return 0;
 118
 119     if (methdata->refcnt_up_method(method)
 120         && ossl_method_store_add(store, methdata->nid, propdef, method,
 121                                  methdata->destruct_method))
 122         return 1;
 123     return 0;
 124 }
 125
 126 static void *construct_method(const OSSL_DISPATCH *fns, OSSL_PROVIDER *prov,
 127                               void *data)
 128 {
 129     struct method_data_st *methdata = data;
 130     void *method = NULL;
 131
 132     if (methdata->nid == NID_undef) {
 133         /* Create a new NID for that name on the fly */
 134         ASN1_OBJECT tmpobj;
 135
 136         /* This is the same as OBJ_create() but without requiring a OID */
 137         tmpobj.nid = OBJ_new_nid(1);
 138         tmpobj.sn = tmpobj.ln = methdata->name;
 139         tmpobj.flags = ASN1_OBJECT_FLAG_DYNAMIC;
 140         tmpobj.length = 0;
 141         tmpobj.data = NULL;
 142
 143         methdata->nid = OBJ_add_object(&tmpobj);
 144     }
 145
 146     if (methdata->nid == NID_undef)
 147         return NULL;
 148
 149     method = methdata->method_from_dispatch(methdata->nid, fns, prov);
 150     if (method == NULL)
 151         return NULL;
 152     return method;
 153 }
 154
 155 static void destruct_method(void *method, void *data)
 156 {
 157     struct method_data_st *methdata = data;
 158
 159     methdata->destruct_method(method);
 160 }
 161
 162 void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 163                         const char *algorithm, const char *properties,
 164                         void *(*new_method)(int nid, const OSSL_DISPATCH *fns,
 165                                             OSSL_PROVIDER *prov),
 166                         int (*upref_method)(void *),
 167                         void (*free_method)(void *))
 168 {
 169     int nid = OBJ_sn2nid(algorithm);
 170     void *method = NULL;
 171
 172     if (nid == NID_undef
 173         || !ossl_method_store_cache_get(NULL, nid, properties, &method)) {
 174         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
 175             alloc_tmp_method_store,
 176             dealloc_tmp_method_store,
 177             get_method_from_store,
 178             put_method_in_store,
 179             construct_method,
 180             destruct_method
 181         };
 182         struct method_data_st mcmdata;
 183
 184         mcmdata.nid = nid;
 185         mcmdata.mcm = &mcm;
 186         mcmdata.method_from_dispatch = new_method;
 187         mcmdata.destruct_method = free_method;
 188         mcmdata.refcnt_up_method = upref_method;
 189         mcmdata.destruct_method = free_method;
 190         method = ossl_method_construct(libctx, operation_id, algorithm,
 191                                        properties, 0 /* !force_cache */,
 192                                        &mcm, &mcmdata);
 193         ossl_method_store_cache_set(NULL, nid, properties, method);
 194     }
 195
 196     return method;
 197 }