'Retrieves a policy attached to the specified key.
:type key_id: string
:param key_id: Unique identifier of the key. This can be an ARN, an
alias, or a globally unique identifier.
:type policy_name: string
:param policy_name: String that contains the name of the policy.
Currently, this must be "default". Policy names can be discovered
by calling ListKeyPolicies.'

def get_key_policy(self, key_id, policy_name):

    params = {'KeyId': key_id, 'PolicyName': policy_name}
    return self.make_request(action='GetKeyPolicy', body=json.dumps(params))
