Re: How to change dologin page from POST to GET and POST
The Share application is not meant at all for access / consumption by other applications. It is a user interface. Apart from completely replacing the core Controller implementation behind the dologin endpoint on a Java level, there is no way to turn the POST-only endpoint to supporting GET+ POST.
Not to mention that GET method is wholy inadequate for authentication purposes: any URL parameters (like user + password) are typically recorded in HTTP access logs.
Depending on your integration scenario, you may want to look at the APIs the underlying repository (ACS) provides, e.g. Public ReST API or CMIS.