You can use a FTP client (or your browser if it supports FTP) and download from the Adobe FTP server (ftp.adobe.com). The files are in /pub/adobe/cs6/downloads :
Windows (launch the .exe which will open the 7z file):
Previous versions are also available in /pub/adobe/photoshop/win and /pub/adobe/photoshop/mac
These folders are public so you don't need any identifier to connect.