[Toybox] secpwgen

[Rob Landley]

On 12/9/20 4:05 PM, scsijon wrote:
> wasn't going to get into this but!2 comments from my OLD security manual since
> this seems to be 'running'.
> 
> 1- This program does not take any steps to initialize the entropy pool. OpenSSL

is not Linux and the kernel does all that for us.
> WIN32 systems)

are not relevant, toybox is written for LP64 and Windows is the one non-LP64
system still in regular use.

> The program will crash if n is too big. No checks are made for the internal
> buffer sizes.

Earning the "sec" prefix, clearly.

> BSD April 4, 2005 BSD you want really secure and unguessable passwords. There
> are many real-life examples where the system security was compromised because of
> poor random number generators.

Which is why I switched from srand((unsigned)time(&t)) with only 25 bits of
possible input in any given year (trivially brute forceable); to kernel getrandom().

By the way, the initial pwgen submission?

  $ for i in 1 2 3 4 5 6 7 8 9 0; do ./pwgen 8 1; done
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa
  h4894yGa

Changes once per second, meaning you only have to guess the second they ran it
on. I.E. "does not spark joy". (Let us not speak of the trailing space on each
entry.)

> 2- The program will crash if n is too big. No checks are made for the internal
> buffer sizes.

This is a repeat? It said already this in the first paragraph?

Rob