How to limit login attempts to Subversion?

Question

We set up a Subversion server via the Apache module mod_dav_svn and the authentification is done via LDAP.
Now we would like to limit the login attempts to Subversion to prevent brute force attacks. If a user (or a bot) enters its password three times wrong, he should be blocked for a specific time.

How can we establish this protection with the setup described above?

Answer 1

mod_dav_svn has an extensive logging feature. Combine this with Fail2ban and you should be able to intercept brute-force login attempts.

Answer 2

You can do that in LDAP itself, if it supports the password policy IETF draft. (OpenLDAP does.) Just set the standard policy's pwdLockout attribute to true, pwdMaxFailure to a non-zero value, say 3 in your case, and pwdLockoutDuration to however many seconds you want the lockout to be, say 300, whatever you think is long enough to deter bots without annoying the hell out of real users.