new

static VALUE
ossl_pkcs7_initialize(int argc, VALUE *argv, VALUE self)
{
    PKCS7 *p7, *pkcs = DATA_PTR(self);
    BIO *in;
    VALUE arg;

    if(rb_scan_args(argc, argv, "01", &arg) == 0)
        return self;
    arg = ossl_to_der_if_possible(arg);
    in = ossl_obj2bio(arg);
    p7 = PEM_read_bio_PKCS7(in, &pkcs, NULL, NULL);
    DATA_PTR(self) = pkcs;
    if (!p7) {
        OSSL_BIO_reset(in);
        p7 = d2i_PKCS7_bio(in, &pkcs);
        if (!p7)
            ossl_raise(rb_eArgError, "Could not parse the PKCS7");
        DATA_PTR(self) = pkcs;
    }
    BIO_free(in);
    ossl_pkcs7_set_data(self, Qnil);
    ossl_pkcs7_set_err_string(self, Qnil);

    return self;
}