suauth
5
Feb 14, 1996
suauth
Detailed su control file
/etc/suauth
DESCRIPTION
The file /etc/suauth is referenced whenever the
su command is called. It can change the behaviour of the su command,
based upon:
1) the user su is targetting
2) the user executing the su command (or any groups he might be
a member of)
The file is formatted like this, with lines starting with a # being
treated as comment lines and ignored;
to-id:from-id:ACTION
Where to-id is either the word ALL, a list of
usernames delimited by "," or the words ALL
EXCEPT followed by a list of usernames delimited by ","
from-id is formatted the same as to-id except the extra word
GROUP is recognised. ALL EXCEPT
GROUP is perfectly valid too. Following
GROUP appears one or more group names, delimited
by ",". It is not sufficient to have primary group id of the relevant
group, an entry in
/etc/group
5 is neccessary.
Action can be one only of the following currently supported options.
DENY
The attempt to su is stopped before a password is
even asked for.
NOPASS
The attempt to su is automatically successful; no password is
asked for.
OWNPASS
For the su command to be successful, the user must enter his or
her own password. They are told this.
Note there are three separate fields delimited by a colon. No
whitespace must surround this colon. Also note that the file is
examined sequentially line by line, and the first applicable rule is
used without examining the file further. This makes it possible for a
system administrator to exercise as fine control as he or she wishes.
EXAMPLE
# sample /etc/suauth file
#
# A couple of privileged usernames may
# su to root with their own password.
#
root:chris,birddog:OWNPASS
#
# Anyone else may not su to root unless in
# group wheel. This is how BSD does things.
#
root:ALL EXCEPT GROUP wheel:DENY
#
# Perhaps terry and birddog are accounts
# owned by the same person.
# Access can be arranged between them
# with no password.
#
terry:birddog:NOPASS
birddog:terry:NOPASS
#
FILES
/etc/suauth
BUGS
There could be plenty lurking. The file parser is particularly
unforgiving about syntax errors, expecting no spurious whitespace
(apart from beginning and end of lines), and a specific token
delimiting different things.
DIAGNOSTICS
An error parsing the file is reported using
syslogd8
as level ERR on facility AUTH.
SEE ALSO
su1
.
AUTHOR
Chris Evans (lady0110@sable.ox.ac.uk)
Lady Margaret Hall
Oxford University
England