'Hacky wrapper to work with S3\'s get_auth_signature.'

def _get_s3_auth_signature(self, params, headers):

    headers_copy = {}
    params_copy = copy.deepcopy(params)
    for (k, v) in headers.items():
        k_lower = k.lower()
        if ((k_lower == 'date') or k_lower.startswith(GoogleStorageDriver.http_vendor_prefix) or (not isinstance(v, str))):
            headers_copy[k_lower] = v
        else:
            headers_copy[k_lower] = v.lower()
    return BaseS3Connection.get_auth_signature(method=self.method, headers=headers_copy, params=params_copy, expires=None, secret_key=self.key, path=self.action, vendor_prefix=GoogleStorageDriver.http_vendor_prefix)
