  /* by other means, required */
int gindex = ...;              /* for the validation */
int pcounter = ...;
int hindex = ...;
OSSL_PARAM extra_params[4];
OSSL_PARAM *domain_params = NULL;
OSSL_PARAM *merged_params = NULL;
EVP_PKEY_CTX *ctx = NULL, *validate_ctx = NULL;
EVP_PKEY *complete_domp = NULL;

EVP_PKEY_todata(received_domp, OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
                &amp;domain_params);
extra_params[0] = OSSL_PARAM_construct_octet_string(&quot;seed&quot;, seed, seedlen);
/*
 * NOTE: For