[luau] Duplicating Music CD

[W. Wayne Liauh]

In UNIX, a code is better than a thousand words.  The following two 
lines of simple code should clearly convey to those in the know the 
power of the setuid bit in UNIX/Linux/xBSD.

/bin/chgrp xcdwrite /usr/bin/cdparanoia
/bin/chmod 4710 /usr/bin/cdparanoia

With cdparanoia/xcdroast, I was able to "rip" a regular audio CD in 
about 10 minutes (compared to sometimes hours with cdda2wav; however, it 
must be noted that I have only very limited experience with either 
program).  Thus, conceivably, it should not be too difficult to write a 
script combining cdparanoia and cdrecord for direct audio copying.



W. Wayne Liauh wrote:

> Very good point(s).  Again, I don't think we can discuss the setuid 
> issue without realizing that we are talking about (1) a 
> consumer-oriented desktop, for which there is necessarily a 
> recognizedly lesser level of security that needs to be implemented, 
> and (2) a set of CDROM-associated programs that are designed to have 
> their setuid turned on (i.e., w/o the options that may cause buffer 
> overflow concerns or other known security issues).  When an executable 
> file has its SUID bit set, the file's owner owns the resulting 
> process, no matter who launched it.  Of course we don't want the SUID 
> bit to be set for every executable program, but sometimes, such as su, 
> sudo as you mentioned, or a printing program such as lpr, this is a 
> necessary evil.
>
> OTOH, you are also exactly right on the wrapper script that's setuid 
> to a certian group that has full access to the CDROM and CD Player.  
> In order to run cdparanoia or cdda2wav, you also have me make yourself 
> member of a group called "xcdwrite".