What I want is the following:
1) Login at a page using Internet Explorer
2) Have my software which uses WinInet API to crawl a site reuse the same cookies/session (i.e. so the crawler is "logged in")
I have tried build login myself using INDY, and while session cookie logins works well, many websites use a more complicated login mechanism nowadays combining client and server side stuff for the initial login.
...
The reason I believe that e.g. WordPress , ASP.Net etc. uses client-side/AJAX stuff as well with hash/time/useragent codes/checks and similar, is that I can be sending the exact same HTTP headers 30 seconds later from my own crawler program as e.g. FireFox used during a login, but it won't work.
(Compare this to normal logins based on session cookies where my own crawler program will login fine.)