Generating Random Passwords with definable length

[Matthias Schniedermeyer <ms@xxxxxxx>]

Hi



Today i had the "problem" that i wanted to create an AES256 Keyfile for 
loop-aes. According to README a SHA512 Hash is used to generate the 
encryption key.

Taking aside the fact halve the bits aren't really put to use here, 
SHA512 still means 64 Byte of raw entropy.

The "standard" example only(tm) gives 45 bytes of entropy, so i thought 
about how i can create random passwords with definable length, only 
using standard unix tools.

So i stumbled over the "openssl" executable and it's many options. Which 
i think sould be available on many systems.

With `openssl enc -base64 -A` you can create base64 encoded strings with 
arbitrary length. So with a little loop around that you can create 
key-files with arbitrary sized lines.

- snip -
for dat in `seq 1 65`; do head -c 90 /dev/random | openssl enc -base64 -A ; echo ; done | gpg --symmetric -a >/a/usbstick/keyfile.gpg
- snip -
90 bytes of entrophy or 120 chars per line in this example.

I think this is also a bit more elegant than the `head`ing and `tail`ing 
in the README.







Bis denn

-- 
Real Programmers consider "what you see is what you get" to be just as 
bad a concept in Text Editors as it is in women. No, the Real Programmer
wants a "you asked for it, you got it" text editor -- complicated, 
cryptic, powerful, unforgiving, dangerous.


-
Linux-crypto:  cryptography in and on the Linux system
Archive:       http://mail.nl.linux.org/linux-crypto/