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In gmane.linux.gentoo.user, you wrote: |
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> On Sunday 15 November 2009 08:21:55 Walter Dnes wrote: |
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>> On Sat, Nov 14, 2009 at 07:07:28PM -0500, Richard Marza wrote |
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>> |
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>> > Thank you for the information, I did find that denyhost and fail2ban in |
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>> > threads but there were issues with it not working properly. Some users |
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>> > created custom scripts to get the job done correctly. |
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>> |
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>> Have you considered not allowing password-based logins at all for ssh? |
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>> Use RSA keys instead. It's much easier, and much more secure. |
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> |
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> fail2ban and/or denyhosts is still very useful with key-only auth, even if |
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> only to get the spam out of messages and into the iptables logs |
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I've hardened ssh by doing the following: |
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* Only allow certain users to ssh |
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* Not allowing passwd login, but only RSA |
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* Switching ssh to a non-standard port |
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This has dramatically reduced the amount of attacks my box gets. It's |
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down to about 2 attacks per year, which is good enough for me. Another |
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trick I learned about, but haven't implemented is changing the version |
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string in sshd by patching the source. Ssh vunarability attacks |
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actually check the version string, so if you change it to something |
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unique, the scripts won't even try to get into your box. |
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