Cain is the first part of the program. Developed with a simple Windows graphical user interface, its main purpose is to concentrate several hacking techniques and proof of concepts providing a simplified tool focused on the recovery of passwords and authentication credentials from various sources.
The user interface is made up of lists, tabs, toolbars and dialogs. Lists are used to contain similar kind of information such as passwords, host names, hashes and other parameters while tabs are used to switch from features. The sniffer toolbar contains only two buttons to activate/deactivate the sniffer and APR functions and the main toolbar the remaining commands to interact with the program.
The blue "+" and the recycle bin buttons on the main toolbar have the general mean to "add something to" and "remove something from" the current list but they performs different actions depending on the currently focused list.
There are also some general Hot Keys in the program to accelerate some functions:
Insert -> Add to List, Insert new entry, new item .......
Delete -> Remove selected items from the current list, Remove all .....
Alt+Del -> Hide Cain's main window
Alt+PgDwn -> Send Cain's main window to system tray
Alt+PgUp -> Restore Cain's main window
F5 -> Refresh list contents
Cain is compiled using Microsoft Visual C++ and linked as a single executable file named "Cain.exe". Although it is principally written in C/C++ a lot of code has been optimized in Assembler for performance reasons. MFC classes and OpenSSL libraries are statically linked to the program; this increases the file size but eliminates the need to distribute shared DLLs.