Path: utzoo!utgpu!water!watmath!clyde!rutgers!rochester!bbn!husc6!cmcl2!brl-adm!brl-smoke!gwyn From: gwyn@brl-smoke.ARPA (Doug Gwyn ) Newsgroups: sci.crypt Subject: Re: Unix Password Hacker Message-ID: <7306@brl-smoke.ARPA> Date: 21 Feb 88 12:11:36 GMT References: <731@ddsw1.UUCP> <203@tijc02.UUCP> <2861@pitt.UUCP> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) ) Distribution: na Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 19 The reason for letting users select their own passwords, apart from eliminating the opportunity for someone else to record what they are, is that they will choose passwords they can remember. Otherwise, you can bet that they'll be written down on little slips of paper, left in desk drawers or written on the desktop pad, etc. Security is actually enhanced by allowing users to pick ones they can remember. Combine this with instructions not to choose something easy for an intruder to guess, such as one's car license plate number, and that is good enough. But you still need to get those encrypted passwords OUT of the publicly-readable /etc/passwd file (replace them with an *). They should be in a separate file that only trusted processes can access for limited purposes (validating and changing the password). Such processes must be designed to take a fair amount of time, to make it infeasible to use them to probe the hidden file. Such an approach keeps a program like the one recently posted from working, while not affecting those programs that get other user information from /etc/passwd.