def make_request_headers(self, request_uri):
        """Generating specific headers from Mimecast credentials."""
        self.request_id = str(uuid.uuid4())
        hdr_date = datetime.datetime.utcnow().strftime("%a, %d %b %Y %H:%M:%S UTC")
        unsigned_auth_header = "{date}:{req_id}:{uri}:{app_key}".format(
            date=hdr_date, req_id=self.request_id, uri=request_uri, app_key=self.app_key
        )
        hmac_sha1 = hmac.new(
            base64.b64decode(self.secret_key), unsigned_auth_header.encode(), digestmod=EncryptionAlgo
        ).digest()
        sig = base64.encodebytes(hmac_sha1).rstrip()
        headers = {
            "Authorization": "MC " + self.access_key + ":" + sig.decode(),
            "x-mc-app-id": self.app_id,
            "x-mc-date": hdr_date,
            "x-mc-req-id": self.request_id,
            "Content-Type": "application/json",
        }
        return headers
Generating specific headers from Mimecast credentials.
Solutions/MimecastTIRegional/Data Connectors/Helpers/threat_intel_feed_request_helper.py