Re: [PATCH] read --echo=[yes|no|wildcard]

[Isaac Dupree]

Robert Millan wrote:
> On Sun, Feb 10, 2008 at 08:56:18AM -0500, Isaac Dupree wrote:
> > Robert Millan wrote:
> > > Adds a parameter to define echoing behaviour in read.  Then one can use
> > > --echo=no or --echo=wildcard to make it suitable for reading passwords.
> > I wonder how suitable it is for passwords -- is the memory always erased 
> > before jumping to e.g. Linux? (and is it important to hide it from the 
> > prying eyes of the root system? Probably...)
>
> Why?  This suggests that the Linux image you just booted is not trusted, which
> I find a bit strange.

well, suppose it runs for a few months, doesn't happen to overwrite that 
memory, and then someone hacks in and gets root access (unpatched 
security flaws can happen) and then reads the raw memory.  Then the 
local boot **and the password itself** might be unknowingly compromised 
(rather than just probably a hash of the password). (plus you might be 
booting Windows ^_^, or anything really.)  It's generally good practice, 
I think... that GnuPG tries to do, for example? (I could be remembering 
wrong)

-Isaac