providers/implementations/keymgmt/kdf_legacy_kmgmt.c

   1 /*
   2  * Copyright 2019-2023 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 /*
  11  * This implemments a dummy key manager for legacy KDFs that still support the
  12  * old way of performing a KDF via EVP_PKEY_derive(). New KDFs should not be
  13  * implemented this way. In reality there is no key data for such KDFs, so this
  14  * key manager does very little.
  15  */
  16
  17 #include <openssl/core_dispatch.h>
  18 #include <openssl/core_names.h>
  19 #include <openssl/err.h>
  20 #include "prov/implementations.h"
  21 #include "prov/providercommon.h"
  22 #include "prov/provider_ctx.h"
  23 #include "prov/kdfexchange.h"
  24
  25 static OSSL_FUNC_keymgmt_new_fn kdf_newdata;
  26 static OSSL_FUNC_keymgmt_free_fn kdf_freedata;
  27 static OSSL_FUNC_keymgmt_has_fn kdf_has;
  28
  29 KDF_DATA *ossl_kdf_data_new(void *provctx)
  30 {
  31     KDF_DATA *kdfdata;
  32
  33     if (!ossl_prov_is_running())
  34         return NULL;
  35
  36     kdfdata = OPENSSL_zalloc(sizeof(*kdfdata));
  37     if (kdfdata == NULL)
  38         return NULL;
  39
  40     if (!CRYPTO_NEW_REF(&kdfdata->refcnt, 1)) {
  41         OPENSSL_free(kdfdata);
  42         return NULL;
  43     }
  44     kdfdata->libctx = PROV_LIBCTX_OF(provctx);
  45
  46     return kdfdata;
  47 }
  48
  49 void ossl_kdf_data_free(KDF_DATA *kdfdata)
  50 {
  51     int ref = 0;
  52
  53     if (kdfdata == NULL)
  54         return;
  55
  56     CRYPTO_DOWN_REF(&kdfdata->refcnt, &ref);
  57     if (ref > 0)
  58         return;
  59
  60     CRYPTO_FREE_REF(&kdfdata->refcnt);
  61     OPENSSL_free(kdfdata);
  62 }
  63
  64 int ossl_kdf_data_up_ref(KDF_DATA *kdfdata)
  65 {
  66     int ref = 0;
  67
  68     /* This is effectively doing a new operation on the KDF_DATA and should be
  69      * adequately guarded again modules' error states.  However, both current
  70      * calls here are guarded properly in exchange/kdf_exch.c.  Thus, it
  71      * could be removed here.  The concern is that something in the future
  72      * might call this function without adequate guards.  It's a cheap call,
  73      * it seems best to leave it even though it is currently redundant.
  74      */
  75     if (!ossl_prov_is_running())
  76         return 0;
  77
  78     CRYPTO_UP_REF(&kdfdata->refcnt, &ref);
  79     return 1;
  80 }
  81
  82 static void *kdf_newdata(void *provctx)
  83 {
  84     return ossl_kdf_data_new(provctx);
  85 }
  86
  87 static void kdf_freedata(void *kdfdata)
  88 {
  89     ossl_kdf_data_free(kdfdata);
  90 }
  91
  92 static int kdf_has(const void *keydata, int selection)
  93 {
  94     return 1; /* nothing is missing */
  95 }
  96
  97 const OSSL_DISPATCH ossl_kdf_keymgmt_functions[] = {
  98     { OSSL_FUNC_KEYMGMT_NEW, (void (*)(void))kdf_newdata },
  99     { OSSL_FUNC_KEYMGMT_FREE, (void (*)(void))kdf_freedata },
 100     { OSSL_FUNC_KEYMGMT_HAS, (void (*)(void))kdf_has },
 101     OSSL_DISPATCH_END
 102 };