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May 19, 2015 - A Look At The New Commandlinefu
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Root Security

Terminal - Root Security
s=/etc/ssh/sshd_config;r=PermitRootLogin;cp $s{,.old}&& if grep $r $s;then sed "s/$r yes/$r no/" $s.old > $s; else echo $r no >> $s;fi
2011-01-30 23:41:59
User: kzh
Functions: cp echo grep sed
Root Security

This will tighten up security for your box. The default value for PermitRootLogin sadly is 'yes'.


There is 1 alternative - vote for the best!

Terminal - Alternatives

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What others think

sed -i.old 's/PermitRootLogin.*yes/PermitRootLogin no/' /etc/ssh/sshd_config && /etc/init.d/ssh reload
Comment by forcefsck 274 weeks and 3 days ago

Yours will not add 'PermitRootLogin no' if the key does not exist at all in the file, however making the execution of your script a failed exercise. The default value of 'PermitRootLogin' is sadly 'yes'! So, since I have built in this precautionary part, why do I get a downvote without an actual well thought reason why?

Comment by kzh 274 weeks and 2 days ago

you got my upvote--even though I would have done it in Perl. =)

Comment by linuxrawkstar 274 weeks and 2 days ago

@linuxrawkstar, you should post your perl one-liner.

Comment by kzh 274 weeks and 1 day ago

@kzh, i didn't vote you down, i didn't vote at all. What I posted was just an instantaneous "or something like this".

Actually your script doesn't have anything special worth voting for. It doesn't change the security level (no ssh reload), it's hardly a one-liner (some independent commands in the same line) and it doesn't take care all the cases, like when PermitRootLogin is commented out.

sorry if I sound critical

Comment by forcefsck 274 weeks and 1 day ago

Sorry, I did not direct that at you, just to whomever. You're right about the comments, though... on both of ours. I am sure somebody could do this with one `ed` script. I would like to see that.

Comment by kzh 274 weeks and 1 day ago

Your point of view

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