Access Control by TCP Wrapper
20131/06/05 |
This is the example for Access Control by TCP Wrapper.
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[1] | Install TCP Wrapper |
root@dlp:~# aptitude -y install tcpd
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[2] | Make sure if a service can be under the TCP Wrapper control or not with the following command. If it includes a link to 'libwrap', it's possible. |
root@dlp:~# ldd /usr/sbin/sshd | grep wrap libwrap.so.0 => /lib/x86_64-linux-gnu/libwrap.so.0 (0x00007f52c7576000) # this service can be under TCP Wrapper control because it includes 'libwrap'
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[3] | Access control by TCP Wrapper is done with '/etc/hosts.allow' and '/etc/hosts.deny'. The example below shows to set access control which allow to access to sshd from 10.0.0.0/24. |
root@dlp:~#
vi /etc/hosts.deny sshd: ALL
root@dlp:~#
vi /etc/hosts.allow sshd: 10.0.0.
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[4] | For the case to allow the access to vsftpd from 'host.example.domain'. |
root@dlp:~#
vi /etc/hosts.deny vsftpd: ALL
root@dlp:~#
vi /etc/hosts.allow vsftpd: host.example.domain
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[5] | For the case to allow access to all services that can be under TCP Wrapper control only from 'example.domain' and '10.0.1.0/24'. |
root@dlp:~#
vi /etc/hosts.deny ALL: ALL
root@dlp:~#
vi /etc/hosts.allow ALL: .example.domain 10.0.1.
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