Encrypts plain buffer with the import key
        :param plain:
        :return:

def encrypt_with_import_key(self, plain):
        """
        Encrypts plain buffer with the import key
        :param plain:
        :return:
        """

        n, e = TemplateProcessor.read_serialized_rsa_pub_key(self.import_key['key'])
        n_bit_size = long_bit_size(n)
        bs = 0
        if n_bit_size > 1024-10 and n_bit_size < 1024+10:
            bs = 128
        elif n_bit_size > 2048-10 and n_bit_size < 2048+10:
            bs = 256
        else:
            raise CryptoError('Unknown RSA modulus size: %d', n_bit_size)

        padded = PKCS15.pad(plain, bs=bs, bt=2)
        return rsa_enc(padded, n, e)