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 char *, const OSSL_DISPATCH *,
  44                                   OSSL_PROVIDER *);
  45     int (*refcnt_up_method)(void *method);
  46     void (*destruct_method)(void *method);
  47 };
  48
  49 /*
  50  * Generic routines to fetch / create EVP methods with ossl_method_construct()
  51  */
  52 static void *alloc_tmp_method_store(OPENSSL_CTX *ctx)
  53 {
  54     return ossl_method_store_new(ctx);
  55 }
  56
  57  static void dealloc_tmp_method_store(void *store)
  58 {
  59     if (store != NULL)
  60         ossl_method_store_free(store);
  61 }
  62
  63 static OSSL_METHOD_STORE *get_default_method_store(OPENSSL_CTX *libctx)
  64 {
  65     return openssl_ctx_get_data(libctx, OPENSSL_CTX_DEFAULT_METHOD_STORE_INDEX,
  66                                 &default_method_store_method);
  67 }
  68
  69 /*
  70  * To identity the method in the method store, we mix the name identity
  71  * with the operation identity, with the assumption that we don't have
  72  * more than 2^24 names or more than 2^8 operation types.
  73  *
  74  * The resulting identity is a 32-bit integer, composed like this:
  75  *
  76  * +---------24 bits--------+-8 bits-+
  77  * |      name identity     | op id  |
  78  * +------------------------+--------+
  79  */
  80 static uint32_t method_id(unsigned int operation_id, unsigned int name_id)
  81 {
  82     if (!ossl_assert(name_id < (1 << 24) || operation_id < (1 << 8))
  83         || !ossl_assert(name_id > 0 && operation_id > 0))
  84         return 0;
  85     return ((name_id << 8) & 0xFFFFFF00) | (operation_id & 0x000000FF);
  86 }
  87
  88 static void *get_method_from_store(OPENSSL_CTX *libctx, void *store,
  89                                    int operation_id, const char *name,
  90                                    const char *propquery, void *data)
  91 {
  92     struct method_data_st *methdata = data;
  93     void *method = NULL;
  94     OSSL_NAMEMAP *namemap;
  95     int nameid;
  96     uint32_t methid;
  97
  98     if (store == NULL
  99         && (store = get_default_method_store(libctx)) == NULL)
 100         return NULL;
 101
 102     if ((namemap = ossl_namemap_stored(libctx)) == NULL
 103         || (nameid = ossl_namemap_name2num(namemap, name)) == 0
 104         || (methid = method_id(operation_id, nameid)) == 0)
 105         return NULL;
 106
 107     (void)ossl_method_store_fetch(store, methid, propquery, &method);
 108
 109     if (method != NULL
 110         && !methdata->refcnt_up_method(method)) {
 111         method = NULL;
 112     }
 113     return method;
 114 }
 115
 116 static int put_method_in_store(OPENSSL_CTX *libctx, void *store,
 117                                void *method, int operation_id,
 118                                const char *name, const char *propdef,
 119                                void *data)
 120 {
 121     struct method_data_st *methdata = data;
 122     OSSL_NAMEMAP *namemap;
 123     int nameid;
 124     uint32_t methid;
 125
 126     if ((namemap = ossl_namemap_stored(methdata->libctx)) == NULL
 127         || (nameid = ossl_namemap_add(namemap, 0, name)) == 0
 128         || (methid = method_id(operation_id, nameid)) == 0)
 129         return 0;
 130
 131     if (store == NULL
 132         && (store = get_default_method_store(libctx)) == NULL)
 133         return 0;
 134
 135     if (methdata->refcnt_up_method(method)
 136         && ossl_method_store_add(store, methid, propdef, method,
 137                                  methdata->destruct_method))
 138         return 1;
 139     return 0;
 140 }
 141
 142 static void *construct_method(const char *name, const OSSL_DISPATCH *fns,
 143                               OSSL_PROVIDER *prov, void *data)
 144 {
 145     struct method_data_st *methdata = data;
 146
 147     return methdata->method_from_dispatch(name, fns, prov);
 148 }
 149
 150 static void destruct_method(void *method, void *data)
 151 {
 152     struct method_data_st *methdata = data;
 153
 154     methdata->destruct_method(method);
 155 }
 156
 157 void *evp_generic_fetch(OPENSSL_CTX *libctx, int operation_id,
 158                         const char *name, const char *properties,
 159                         void *(*new_method)(const char *name,
 160                                             const OSSL_DISPATCH *fns,
 161                                             OSSL_PROVIDER *prov),
 162                         int (*up_ref_method)(void *),
 163                         void (*free_method)(void *))
 164 {
 165     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 166     OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
 167     int nameid = 0;
 168     uint32_t methid = 0;
 169     void *method = NULL;
 170
 171     if (store == NULL || namemap == NULL)
 172         return NULL;
 173
 174     /*
 175      * If there's ever an operation_id == 0 passed, we have an internal
 176      * programming error.
 177      */
 178     if (!ossl_assert(operation_id > 0))
 179         return NULL;
 180
 181     /*
 182      * method_id returns 0 if we have too many operations (more than
 183      * about 2^8) or too many names (more than about 2^24).  In that
 184      * case, we can't create any new method.
 185      */
 186     if ((nameid = ossl_namemap_name2num(namemap, name)) != 0
 187         && (methid = method_id(operation_id, nameid)) == 0)
 188         return NULL;
 189
 190     if (nameid == 0
 191         || !ossl_method_store_cache_get(store, methid, properties,
 192                                         &method)) {
 193         OSSL_METHOD_CONSTRUCT_METHOD mcm = {
 194             alloc_tmp_method_store,
 195             dealloc_tmp_method_store,
 196             get_method_from_store,
 197             put_method_in_store,
 198             construct_method,
 199             destruct_method
 200         };
 201         struct method_data_st mcmdata;
 202
 203         mcmdata.mcm = &mcm;
 204         mcmdata.libctx = libctx;
 205         mcmdata.name = name;
 206         mcmdata.method_from_dispatch = new_method;
 207         mcmdata.destruct_method = free_method;
 208         mcmdata.refcnt_up_method = up_ref_method;
 209         mcmdata.destruct_method = free_method;
 210         if ((method = ossl_method_construct(libctx, operation_id, name,
 211                                             properties, 0 /* !force_cache */,
 212                                             &mcm, &mcmdata)) != NULL) {
 213             /*
 214              * If construction did create a method for us, we know that
 215              * there is a correct nameid and methodid, since those have
 216              * already been calculated in get_method_from_store() and
 217              * put_method_in_store() above.
 218              */
 219             nameid = ossl_namemap_name2num(namemap, name);
 220             methid = method_id(operation_id, nameid);
 221             ossl_method_store_cache_set(store, methid, properties, method);
 222         }
 223     } else {
 224         up_ref_method(method);
 225     }
 226
 227     return method;
 228 }
 229
 230 int EVP_set_default_properties(OPENSSL_CTX *libctx, const char *propq)
 231 {
 232     OSSL_METHOD_STORE *store = get_default_method_store(libctx);
 233
 234     if (store != NULL)
 235         return ossl_method_store_set_global_properties(store, propq);
 236     EVPerr(EVP_F_EVP_SET_DEFAULT_PROPERTIES, ERR_R_INTERNAL_ERROR);
 237     return 0;
 238 }
 239
 240 struct do_all_data_st {
 241     void (*user_fn)(void *method, void *arg);
 242     void *user_arg;
 243     void *(*new_method)(const char *name, const OSSL_DISPATCH *fns,
 244                         OSSL_PROVIDER *prov);
 245     void (*free_method)(void *);
 246 };
 247
 248 static void do_one(OSSL_PROVIDER *provider, const OSSL_ALGORITHM *algo,
 249                    int no_store, void *vdata)
 250 {
 251     struct do_all_data_st *data = vdata;
 252     void *method = data->new_method(algo->algorithm_name,
 253                                     algo->implementation, provider);
 254
 255     if (method != NULL) {
 256         data->user_fn(method, data->user_arg);
 257         data->free_method(method);
 258     }
 259 }
 260
 261 void evp_generic_do_all(OPENSSL_CTX *libctx, int operation_id,
 262                         void (*user_fn)(void *method, void *arg),
 263                         void *user_arg,
 264                         void *(*new_method)(const char *name,
 265                                             const OSSL_DISPATCH *fns,
 266                                             OSSL_PROVIDER *prov),
 267                         void (*free_method)(void *))
 268 {
 269     struct do_all_data_st data;
 270
 271     data.new_method = new_method;
 272     data.free_method = free_method;
 273     data.user_fn = user_fn;
 274     data.user_arg = user_arg;
 275     ossl_algorithm_do_all(libctx, operation_id, NULL, do_one, &data);
 276 }