Hello All,

I am trying to access API with Digest Authentication via S7-1200 PLC.

Without authentication it works.

With Basic Authentication it also works.

But with Digest Authentication I am facing issue.

I tried it from POSTMAN and works perfectly. So I monitored this POSTMAN request in Wireshark.

And i observed that first it sends request without username & password. It receives 401 error with other data like realM, nonce etc. It again sends request with authentication headers data (received from previous request) and it receives with 200 message.

So, basically in one request by Postman, it performs two GET requests in backends. I also studied about Digest Authentication Process, it also says same think that 

Step-1) It sends only url with GET/POST command. It replies with 401(Authorization Error) with other data like realM, nonce, etc.

Step-2) Send it again with Digest Authorization Header with realM, nonce and many other data received in STEP-1 reply. And this time it receives 200.

So, I also tried to simulate this thing manually by PLC. But i did not succussed. I receives 401 Error always.

I also attached Wireshark Monitoring File for details. Just open it, and apply current filer http, you can see it. Also attached screen shots of it.

Any body observed this?

Please help me how to execute http request with Digest Authentication.

Any body have idea about this?

How to access API with Digest Authentication?

Please Help me..