crypto/dh/dh_kdf.c

   1 /*
   2  * Copyright 2013-2019 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 "e_os.h"
  11
  12 #ifndef OPENSSL_NO_CMS
  13 # include <string.h>
  14 # include <openssl/core_names.h>
  15 # include <openssl/dh.h>
  16 # include <openssl/evp.h>
  17 # include <openssl/asn1.h>
  18 # include <openssl/kdf.h>
  19 # include <internal/provider.h>
  20
  21 int DH_KDF_X9_42(unsigned char *out, size_t outlen,
  22                  const unsigned char *Z, size_t Zlen,
  23                  ASN1_OBJECT *key_oid,
  24                  const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
  25 {
  26     int ret = 0, nid;
  27     EVP_KDF_CTX *kctx = NULL;
  28     EVP_KDF *kdf = NULL;
  29     const char *oid_sn;
  30     OSSL_PARAM params[5], *p = params;
  31     const char *mdname = EVP_MD_name(md);
  32     const OSSL_PROVIDER *prov = EVP_MD_provider(md);
  33     OPENSSL_CTX *provctx = ossl_provider_library_context(prov);
  34
  35     nid = OBJ_obj2nid(key_oid);
  36     if (nid == NID_undef)
  37         return 0;
  38     oid_sn = OBJ_nid2sn(nid);
  39     if (oid_sn == NULL)
  40         return 0;
  41
  42     kdf = EVP_KDF_fetch(provctx, SN_x942kdf, NULL);
  43     if ((kctx = EVP_KDF_CTX_new(kdf)) == NULL)
  44         goto err;
  45     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
  46                                             (char *)mdname, strlen(mdname) + 1);
  47     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
  48                                              (unsigned char *)Z, Zlen);
  49     if (ukm != NULL)
  50         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_UKM,
  51                                                  (unsigned char *)ukm, ukmlen);
  52     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_CEK_ALG,
  53                                             (char *)oid_sn, strlen(oid_sn) + 1);
  54     *p = OSSL_PARAM_construct_end();
  55     ret = EVP_KDF_CTX_set_params(kctx, params) > 0
  56         && EVP_KDF_derive(kctx, out, outlen) > 0;
  57 err:
  58     EVP_KDF_CTX_free(kctx);
  59     EVP_KDF_free(kdf);
  60     return ret;
  61 }
  62 #endif /* OPENSSL_NO_CMS */