On Fri, Jan 23, 2009 at 3:18 PM, Paul Hartman <[email protected]> wrote: > On Fri, Jan 23, 2009 at 2:22 PM, Paul Hartman > <[email protected]> wrote: >> On Tue, Jan 20, 2009 at 3:33 PM, Paul Hartman >> <[email protected]> wrote: >>> Hi, >>> >>> After setting up public key authentication i changed my sshd back to >>> port 22 and got the expected bombardment of connection attempts. >>> However, it doesn't seem to ever stop them. I'm using sshd with this >>> setting: >>> >>> MaxAuthTries 3 >>> >>> in my /etc/ssh/sshd_config >> [cut] >> >> Okay, I have some possible new embarrassing information... as well as >> some new questions about access control. After combining all logs in >> chronological order, it appears denyhosts IS properly adding the new >> host to /etc/hosts.deny but it is simply not causing it to be >> denied... See this sample: >> >> Jan 22 18:42:58 [sshd] Invalid user staff from 59.185.104.218 >> Jan 22 18:43:01 [sshd] Invalid user sales from 59.185.104.218 >> Jan 22 18:43:03 [sshd] Invalid user recruit from 59.185.104.218 >> Jan 22 18:43:06 [denyhosts] Added the following hosts to >> /etc/hosts.deny - 59.185.104.218 >> (triband-mum-59.185.104.218.mtnl.net.in) >> Jan 22 18:43:06 [sshd] Invalid user alias from 59.185.104.218 >> Jan 22 18:43:09 [sshd] Invalid user office from 59.185.104.218 >> Jan 22 18:43:11 [sshd] Invalid user samba from 59.185.104.218 >> Jan 22 18:43:14 [sshd] Invalid user tomcat from 59.185.104.218 >> Jan 22 18:43:22 [sshd] Invalid user webadmin from 59.185.104.218 >> >> So now I am going back to what I should have looked at in the very >> beginning, my hosts.allow and hosts.deny rules. >> >> hosts.allow: >> sshd: ALL >> portmap: 127.0.0.1, 192.168.0.0/255.255.255.0 >> lockd: 127.0.0.1, 192.168.0.0/255.255.255.0 >> rquotad: 127.0.0.1, 192.168.0.0/255.255.255.0 >> mountd: 127.0.0.1, 192.168.0.0/255.255.255.0 >> statd: 127.0.0.1, 192.168.0.0/255.255.255.0 >> ALL: 127.0.0.1, 192.168.0.0/255.255.255.0 >> >> >> hosts.deny: >> ALL: ALL >> sshd: 58.213.125.25 >> sshd: 75.37.250.107 >> sshd: 147.83.29.83 >> sshd: 59.185.104.218 >> sshd: 210.40.128.31 >> (and so on) >> >> From the manpage: >> >> ACCESS CONTROL FILES >> The access control software consults two files. The search >> stops at the first match: >> - Access will be granted when a (daemon,client) pair >> matches an entry in the /etc/hosts.allow file. >> - Otherwise, access will be denied when a (daemon,client) >> pair matches an entry in the /etc/hosts.deny file. >> - Otherwise, access will be granted. >> >> doh! So, basically, when it sees sshd: ALL in hosts.allow, it stops >> and allows access to everyone. It never even gets around to checking >> the hosts.deny file. The fact that the login attempts stopped after >> about an hour must have been purely coincidence. >> >> My intended purpose for those entires was to allow all sshd unless >> they are in the deny file, but I also want to deny everything else >> that doesn't have an explicit allow/deny rule. I don't think this is >> possible using hosts.allow/hosts.deny unless I enumerate every >> service. The deny ALL: ALL will deny me access to sshd. >> >> I essentially want it to work the other way around. Deny access by >> default unless there is an allow rule. I don't think I can do that, >> though. If I put ALL: ALL or sshd: ALL in the hosts.deny file, it will >> deny ME access to my own machine. I don't want that. Since I don't >> have a specific IP i will connect from, I can't allow any specific IP >> (or else I'd be doing it that way already). >> >> How can I accomplish this?: >> >> Allow all ssh connections unless they are in hosts.deny >> Deny all other connections unless they are in hosts.allow >> >> Thanks and sorry for the misdirection :) >> Paul >> > > After reading more, I see there is an EXCEPT rule as well.. so I can > theoretically deny: > > ALL: ALL EXCEPT sshd > and hopefully that will do what I was wanting... time to try it :)
Sorry, i made a typo in my email. ALL EXCEPT sshd: ALL Tested and working. Paul
