Problem with openssh-4.0p1 and tcp wrappers on RH7.2(Scyld)
Bengt Svensson
bsven at msi.umn.edu
Sat Apr 16 12:34:46 EST 2005
I have tried to update openssh-3.1p1 of our system that uses RH7.2 (Scyld).
I is pretty much a standard Redhat 7.2 install with openssl-0.9.6b,
zlib-1.1.4 etc.
I have gotten openssh to work after some initial issues, but I still
have not been able to get openssh/sshd to work with tcp-wrappers.
I have in hosts.deny
ALL: ALL:
and in hosts.allow
ALL: localhost, 127.0.0.1, 192.168.1.
and still I can connect with ssh from outside that allowed ip range.
tcp-wrapper is working, anything else but ssh is blocked.
On another machine that is running the same OS but with openssh-3.1p1 the
blocking works.
What could be the problem? Why can't I block ssh logins?
Can someone explain to me what is going on and how I can improve the
situation.
I followed the instructions in the INSTALL file and compiled a
openssh-4.0p1 with the following options (to match the dirs of the
previous version). The configure out put is attached.
$ ./configure --prefix= --sysconfdir=/etc/ssh
--libexecdir=/usr/libexec/openssh --mandir=/usr/share/man
--with-tcp-wrappers -with-md5-passwords
$ make
$ make install
To get things to work I had to perform the following steps that were not
described in the INSTALL file. I wish the INSTALL file would have been
more thurough and mentioned this.
$ mkdir /var/empty
$ chown root:sys /var/empty
$ chmod 755 /var/empty
$ groupadd -g 74 sshd
$ useradd -g sshd -c 'Privilege-separated SSH' -u 74 -d /var/empty -s
/bin/nologin sshd
I then restarted sshd with
$ /etc/init.d/sshd restart
or rebooted the system.
The previous version might have had PAM included, but when I add -with-pam
to configure. I get some more warnings at compile and an error of
something like 'Unsupported option' when sshd is restarted and when
I have UsePAM yes in the sshd_config file.
Another issue I have found is that when enableing the
'MaxAuthTries 3' option in sssh_config (as I have seen recommended) and
restart sshd, I get the message 'Bad Configuration option' and sshd will
not start.
I would appreciate any help.
Thanks,
Bengt Svensson
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