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/namemap.h"
  19 #include "internal/evp_int.h"    /* evp_locl.h needs it */
  20 #include "evp_locl.h"
  21
  22 static void default_method_store_free(void *vstore)
  23 {
  24     ossl_method_store_free(vstore);
  25 }
  26
  27 static void *default_method_store_new(OPENSSL_CTX *ctx)
  28 {
  29     return ossl_method_store_new(ctx);
  30 }
  31
  32
  33 static const OPENSSL_CTX_METHOD default_method_store_method = {
  34     default_method_store_new,
  35     default_method_store_free,
  36 };
  37
  38 /* Data to be passed through ossl_method_construct() */
  39 struct method_data_st {
  40     OPENSSL_CTX *libctx;
  41     const char *name;
  42     OSSL_METHOD_CONSTRUCT_METHOD *mcm;
  43     void *(*method_from_dispatch)(const OSSL_DISPATCH *, OSSL_PROVIDER *);
  44     int (*refcnt_up_method)(void *method);
  45     void (*destruct_method)(void *method);
  46 };
  47
  48 /*
  49  * Generic routines to fetch / create EVP methods with ossl_method_construct()
  50  */
  51 static void *alloc_tmp_method_store(OPENSSL_CTX *ctx)
  52 {
  53     return ossl_method_store_new(ctx);
  54 }
  55
  56  static void dealloc_tmp_method_store(void *store)
  57 {
  58     if (store != NULL)
  59         ossl_method_store_free(store);
  60 }
  61
  62 static OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
  63 {
  64     return openssl_ctx_get_data(libctx, OPENSSL_CTX_DEFAULT_METHOD_STORE_INDEX,
  65                                 &default_method_store_method);
  66 }
  67
  68 /*
  69  * To identity the method in the method store, we mix the name identity
  70  * with the operation identity, with the assumption that we don't have
  71  * more than 2^24 names or more than 2^8 operation types.
  72  *
  73  * The resulting identity is a 32-bit integer, composed like this:
  74  *
  75  * +---------24 bits--------+-8 bits-+
  76  * |      name identity     | op id  |
  77  * +------------------------+--------+
  78  */
  79 static uint32_t method_id(unsigned int operation_id, unsigned int name_id)
  80 {
  81     if (!ossl_assert(name_id < (1 << 24) || operation_id < (1 << 8))
  82         || !ossl_assert(name_id > 0 && operation_id > 0))
  83         return 0;
  84     return ((name_id << 8) & 0xFFFFFF00) | (operation_id & 0x000000FF);
  85 }
  86
  87 static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
  88                                    int operation_id, const char *name,
  89                                    const char *propquery, void *data)
  90 {
  91     struct method_data_st *methdata = data;
  92     void *method = NULL;
  93     OSSL_NAMEMAP *namemap;
  94     int nameid;
  95     uint32_t methid;
  96
  97     if (store == NULL
  98         && (store = get_default_method_store(libctx)) == NULL)
  99         return NULL;
 100
 101     if ((namemap = ossl_namemap_stored(libctx)) == NULL
 102         || (nameid = ossl_namemap_name2num(namemap, name)) == 0
 103         || (methid = method_id(operation_id, nameid)) == 0)
 104         return NULL;
 105
 106     (void)ossl_method_store_fetch(store, methid, propquery, &method);
 107
 108     if (method != NULL
 109         && !methdata->refcnt_up_method(method)) {
 110         method = NULL;
 111     }
 112     return method;
 113 }
 114
 115 static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
 116                                void *method, int operation_id,
 117                                const char *name, const char *propdef,
 118                                void *data)
 119 {
 120     struct method_data_st *methdata = data;
 121     OSSL_NAMEMAP *namemap;
 122     int nameid;
 123     uint32_t methid;
 124
 125     if ((namemap = ossl_namemap_stored(methdata->libctx)) == NULL
 126         || (nameid = ossl_namemap_add(namemap, 0, name)) == 0
 127         || (methid = method_id(operation_id, nameid)) == 0)
 128         return 0;
 129
 130     if (store == NULL
 131         && (store = get_default_method_store(libctx)) == NULL)
 132         return 0;
 133
 134     if (methdata->refcnt_up_method(method)
 135         && ossl_method_store_add(store, methid, propdef, method,
 136                                  methdata->destruct_method))
 137         return 1;
 138     return 0;
 139 }
 140
 141 static void *construct_method(const char *name, const OSSL_DISPATCH *fns,
 142                               OSSL_PROVIDER *prov, void *data)
 143 {
 144     struct method_data_st *methdata = data;
 145
 146     return methdata->method_from_dispatch(fns, prov);
 147 }
 148
 149 static void destruct_method(void *method, void *data)
 150 {
 151     struct method_data_st *methdata = data;
 152
 153     methdata->destruct_method(method);
 154 }
 155
 156 void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 157                         const char *name, const char *properties,
 158                         void *(*new_method)(const OSSL_DISPATCH *fns,
 159                                             OSSL_PROVIDER *prov),
 160                         int (*upref_method)(void *),
 161                         void (*free_method)(void *))
 162 {
 163     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 164     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 165     int nameid = 0;
 166     uint32_t methid = 0;
 167     void *method = NULL;
 168
 169     if (store == NULL || namemap == NULL)
 170         return NULL;
 171
 172     /*
 173      * If there's ever an operation_id == 0 passed, we have an internal
 174      * programming error.
 175      */
 176     if (!ossl_assert(operation_id > 0))
 177         return NULL;
 178
 179     /*
 180      * method_id returns 0 if we have too many operations (more than
 181      * about 2^8) or too many names (more than about 2^24).  In that
 182      * case, we can't create any new method.
 183      */
 184     if ((nameid = ossl_namemap_name2num(namemap, name)) != 0
 185         && (methid = method_id(operation_id, nameid)) == 0)
 186         return NULL;
 187
 188     if (nameid == 0
 189         || !ossl_method_store_cache_get(store, methid, properties,
 190                                         &method)) {
 191         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
 192             alloc_tmp_method_store,
 193             dealloc_tmp_method_store,
 194             get_method_from_store,
 195             put_method_in_store,
 196             construct_method,
 197             destruct_method
 198         };
 199         struct method_data_st mcmdata;
 200
 201         mcmdata.mcm = &mcm;
 202         mcmdata.libctx = libctx;
 203         mcmdata.name = name;
 204         mcmdata.method_from_dispatch = new_method;
 205         mcmdata.destruct_method = free_method;
 206         mcmdata.refcnt_up_method = upref_method;
 207         mcmdata.destruct_method = free_method;
 208         if ((method = ossl_method_construct(libctx, operation_id, name,
 209                                             properties, 0 /* !force_cache */,
 210                                             &mcm, &mcmdata)) == NULL) {
 211             /*
 212              * If construction did create a method for us, we know that
 213              * there is a correct nameid and methodid, since those have
 214              * already been calculated in get_method_from_store() and
 215              * put_method_in_store() above.
 216              */
 217             nameid = ossl_namemap_name2num(namemap, name);
 218             methid = method_id(operation_id, nameid);
 219             ossl_method_store_cache_set(store, methid, properties, method);
 220         }
 221     } else {
 222         upref_method(method);
 223     }
 224
 225     return method;
 226 }
 227
 228 int EVP_set_default_properties(OPENSSL_CTX *libctx, const char *propq)
 229 {
 230     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 231
 232     if (store != NULL)
 233         return ossl_method_store_set_global_properties(store, propq);
 234     EVPerr(EVP_F_EVP_SET_DEFAULT_PROPERTIES, ERR_R_INTERNAL_ERROR);
 235     return 0;
 236 }