On Thu, May 13, 2004 at 05:55:03PM -0400, Kent Borg wrote: > On Thu, May 13, 2004 at 02:26:08PM -0700, Vladimir G. Ivanovic wrote: > > I am not logged in remotely but locally. I've had a "cat /dev/random" > > running in a GNOME Terminal tab (window) now for several hours while I > > read mail & surfed. > > Eeek! > > One of the problems with /dev/random (as opposed to /dev/urandom) is > that any user can read it, drain all the entropy, and prevent others > from getting any. As a test it can be interesting, but don't do that > otherwise. (Don't forget an extra cat left running on a different > console.) > > Kill the cat. cd to /proc/sys/kernel/random and look around. > Specifically, cat entropy_avail. I am guessing you will see nothing. > Now cat a few bytes into /dev/random and cat entropy_avail again. Did > any show up? If so, then things are as I expect, you need to tell > your mouse and keyboard and other devices to contribute entropy. I > would have to start searching through kernel sources and googling to > find out how. > > -kb, the Kent who has run off the end of his immediate knowledge. > > > P.S. Did you do a standard install? What strange things have you > done? (Compile your own kernel? Mess with boot initializations?) I have only just had a chance to try the above and found the following: 1. cat entropy_avail returned 4096 2. I cat-ed a small file into /dev/random. The cat just went on with random characters on screen until I hit crtl-C. 3. cat entropy_avail returned 177 This is not what you said would happen and I am at a loss what this all means. Any clarification? -- ------------------------------------------- Aaron Konstam Computer Science Trinity University One Trinity Place. San Antonio, TX 78212-7200 telephone: (210)-999-7484 email:akonstam@xxxxxxxxxxx
