text: /*
   * Copyright 2013-2021 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  /*
   * DH low level APIs are deprecated for public use, but still ok for
   * internal use.
   */
  #include "internal/deprecated.h"
  
  #include "e_os.h"
  #include "e_os.h"
  #include <string.h>
  #include <openssl/core_names.h>
  #include <openssl/dh.h>
  #include <openssl/evp.h>
  #include <openssl/asn1.h>
  #include <openssl/kdf.h>
  #include <internal/provider.h>
  #include <crypto/dh.h>
  
  /* Key derivation function from X9.63/SECG */
  int ossl_dh_kdf_X9_42_asn1(unsigned char *out, size_t outlen,
                             const unsigned char *Z, size_t Zlen,
                             const char *cek_alg,
                             const unsigned char *ukm, size_t ukmlen,
                             const EVP_MD *md,
                             OSSL_LIB_CTX *libctx, const char *propq)
  {
      int ret = 0;
      EVP_KDF_CTX *kctx = NULL;
      EVP_KDF *kdf = NULL;
      OSSL_PARAM params[5], *p = params;
      const char *mdname = EVP_MD_name(md);
  
      kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_X942KDF_ASN1, propq);
      kctx = EVP_KDF_CTX_new(kdf);
      if (kctx == NULL)
          goto err;
  
      *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
                                              (char *)mdname, 0);
      *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
                                               (unsigned char *)Z, Zlen);
      if (ukm != NULL)
          *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_UKM,
                                                   (unsigned char *)ukm, ukmlen);
      *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_CEK_ALG,
                                              (char *)cek_alg, 0);
      *p = OSSL_PARAM_construct_end();
      ret = EVP_KDF_derive(kctx, out, outlen, params) > 0;
  err:
      EVP_KDF_CTX_free(kctx);
      EVP_KDF_free(kdf);
      return ret;
  }
  
  #if !defined(FIPS_MODULE)
  int DH_KDF_X9_42(unsigned char *out, size_t outlen,
                   const unsigned char *Z, size_t Zlen,
                   ASN1_OBJECT *key_oid,
                   const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
  {
      int nid;
      const char *key_alg = NULL;
      const OSSL_PROVIDER *prov = EVP_MD_provider(md);
      OSSL_LIB_CTX *libctx = ossl_provider_libctx(prov);
  
      nid = OBJ_obj2nid(key_oid);
      if (nid == NID_undef)
          return 0;
      key_alg = OBJ_nid2sn(nid);
      if (key_alg == NULL)
          return 0;
  
      return ossl_dh_kdf_X9_42_asn1(out, outlen, Z, Zlen, key_alg,
                                    ukm, ukmlen, md, libctx, NULL);
  }
  #endif /* !defined(FIPS_MODULE) */
  