From 6f958e14be6fc2683684aea2a11744a96f67f2ea Mon Sep 17 00:00:00 2001
From: Jannis R <mail@jannisr.de>
Date: Mon, 15 Jan 2018 00:45:40 +0100
Subject: [PATCH] mic & mac calculation

thanks to @alexander-albers!
see https://github.com/schildbach/public-transport-enabler/issues/187#issuecomment-357436079
---
 lib/default-profile.js |  1 +
 lib/request.js         | 21 +++++++++++++++------
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/lib/default-profile.js b/lib/default-profile.js
index 1e767cbc..7abcf60d 100644
--- a/lib/default-profile.js
+++ b/lib/default-profile.js
@@ -28,6 +28,7 @@ const id = x => x
 const defaultProfile = {
 	salt: null,
 	addChecksum: false,
+	addMicMac: false,
 
 	transformReqBody: id,
 	transformReq: id,
diff --git a/lib/request.js b/lib/request.js
index d4494f91..cc5192a9 100644
--- a/lib/request.js
+++ b/lib/request.js
@@ -26,15 +26,24 @@ const request = (profile, data) => {
 		query: {}
 	})
 
-	if (profile.addChecksum) {
+	if (profile.addChecksum || profile.addMicMac) {
 		if (!Buffer.isBuffer(profile.salt)) {
 			throw new Error('profile.salt must be a Buffer.')
 		}
-		const checksum = md5(Buffer.concat([
-			Buffer.from(req.body, 'utf8'),
-			profile.salt
-		]))
-		req.query.checksum = checksum.toString('hex')
+		if (profile.addChecksum) {
+			const checksum = md5(Buffer.concat([
+				Buffer.from(req.body, 'utf8'),
+				profile.salt
+			]))
+			req.query.checksum = checksum.toString('hex')
+		}
+		if (profile.addMicMac) {
+			const mic = md5(Buffer.from(req.body, 'utf8'))
+			req.query.mic = mic.toString('hex')
+
+			const mac = md5(Buffer.concat([mic, profile.salt]))
+			req.query.mac = mac.toString('hex')
+		}
 	}
 
 	const url = profile.endpoint +'?' + stringify(req.query)