OpenSSL::PKey::EC.new

static VALUE ossl_ec_key_initialize(int argc, VALUE *argv, VALUE self)
{
    EVP_PKEY *pkey;
    EC_KEY *ec;
    BIO *in;
    VALUE arg, pass;
    int type;

    TypedData_Get_Struct(self, EVP_PKEY, &ossl_evp_pkey_type, pkey);
    if (pkey)
        rb_raise(rb_eTypeError, "pkey already initialized");

    rb_scan_args(argc, argv, "02", &arg, &pass);
    if (NIL_P(arg)) {
#ifdef OSSL_HAVE_IMMUTABLE_PKEY
        rb_raise(rb_eArgError, "OpenSSL::PKey::EC.new cannot be called " \
                 "without arguments; pkeys are immutable with OpenSSL 3.0");
#else
        if (!(ec = EC_KEY_new()))
            ossl_raise(ePKeyError, "EC_KEY_new");
        goto legacy;
#endif
    }
    else if (rb_obj_is_kind_of(arg, cEC_GROUP)) {
        ec = ec_key_new_from_group(arg);
        goto legacy;
    }

    pass = ossl_pem_passwd_value(pass);
    arg = ossl_to_der_if_possible(arg);
    in = ossl_obj2bio(&arg);

    pkey = ossl_pkey_read_generic(in, pass);
    BIO_free(in);
    if (!pkey) {
        ossl_clear_error();
        ec = ec_key_new_from_group(arg);
        goto legacy;
    }

    type = EVP_PKEY_base_id(pkey);
    if (type != EVP_PKEY_EC) {
        EVP_PKEY_free(pkey);
        rb_raise(ePKeyError, "incorrect pkey type: %s", OBJ_nid2sn(type));
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;

  legacy:
    pkey = EVP_PKEY_new();
    if (!pkey || EVP_PKEY_assign_EC_KEY(pkey, ec) != 1) {
        EVP_PKEY_free(pkey);
        EC_KEY_free(ec);
        ossl_raise(ePKeyError, "EVP_PKEY_assign_EC_KEY");
    }
    RTYPEDDATA_DATA(self) = pkey;
    return self;
}