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 /*
  11  * DH low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include "e_os.h"
  17
  18 #ifndef OPENSSL_NO_CMS
  19 # include <string.h>
  20 # include <openssl/core_names.h>
  21 # include <openssl/dh.h>
  22 # include <openssl/evp.h>
  23 # include <openssl/asn1.h>
  24 # include <openssl/kdf.h>
  25 # include <internal/provider.h>
  26
  27 int DH_KDF_X9_42(unsigned char *out, size_t outlen,
  28                  const unsigned char *Z, size_t Zlen,
  29                  ASN1_OBJECT *key_oid,
  30                  const unsigned char *ukm, size_t ukmlen, const EVP_MD *md)
  31 {
  32     int ret = 0, nid;
  33     EVP_KDF_CTX *kctx = NULL;
  34     EVP_KDF *kdf = NULL;
  35     const char *oid_sn;
  36     OSSL_PARAM params[5], *p = params;
  37     const char *mdname = EVP_MD_name(md);
  38     const OSSL_PROVIDER *prov = EVP_MD_provider(md);
  39     OPENSSL_CTX *provctx = ossl_provider_library_context(prov);
  40
  41     nid = OBJ_obj2nid(key_oid);
  42     if (nid == NID_undef)
  43         return 0;
  44     oid_sn = OBJ_nid2sn(nid);
  45     if (oid_sn == NULL)
  46         return 0;
  47
  48     kdf = EVP_KDF_fetch(provctx, OSSL_KDF_NAME_X942KDF, NULL);
  49     if ((kctx = EVP_KDF_CTX_new(kdf)) == NULL)
  50         goto err;
  51     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
  52                                             (char *)mdname, 0);
  53     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
  54                                              (unsigned char *)Z, Zlen);
  55     if (ukm != NULL)
  56         *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_UKM,
  57                                                  (unsigned char *)ukm, ukmlen);
  58     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_CEK_ALG,
  59                                             (char *)oid_sn, 0);
  60     *p = OSSL_PARAM_construct_end();
  61     ret = EVP_KDF_CTX_set_params(kctx, params) > 0
  62         && EVP_KDF_derive(kctx, out, outlen) > 0;
  63 err:
  64     EVP_KDF_CTX_free(kctx);
  65     EVP_KDF_free(kdf);
  66     return ret;
  67 }
  68 #endif /* OPENSSL_NO_CMS */