Programmatically login at http response HTML page

[konstantinos_vassiliadis]

Hello experts,

I am trying to implement OAuth2 communication between SAP and an external provider. I am using Authorization Code grant type since this is required from the resource owner. 

Initially I call the Authorization endpoint with the proper querystring and in the response I get an HTML page which requires username and password.

If I invoke the Authorization endpoint from a browser it brings up the HTML page with two placeholders for username and password and after successful login the browser is re-directed to the Redirection URI specified during registration at the provider's portal. Part of the URL of the re-directed URL is the authorization code which I want to use for getting an access token. It is this part that I want to achieve programmatically i.e. the provision of the credentials to the initial HTML page so that after submission I get a new response (from re-direction) from where I get the authorization code by analyzing the response querystring.

Any ideas how to achieve the log-in page submission?

Kind regards,

Konstantinos