This mini HOW-TO is for those who are in the urge of using a Subversion server behind a windows based Apache secured by mod_auth_sspi.
Suppose you have a similar environment for your Subversion. The Hudson part is irrelevant in this context.
When you try to setup your project with Subversion then Hudson refuses to connect to the svn repository declared in your hudson job when the access to the repository is protected by mod_auth_sspi. You get this kind of exception from Hudson (lines wrapped for better readability):
My guess is that the mod_auth_sspi (NTLM) does not understand what the svnkit (Basic Authentication) of Hudson says to authenticate. (It is my assumption because I am not a Microsoft-Techie - I prefer open standards and sources.) The credentials you enter in Hudson do not make their way into the mod_auth_sspi. Side note: They get send from Hudson: you will see them when you disable ssl and sniff the packets on the wire.
In your Apache error.log you will see an empty user, even when you provided a user name in Hudson. Note the "user unknown" text in the end of the log entry:
Lets solve this...
The idea is to enforce the mod_auth_sspi to offer Basic Authentication and to challenge Basic Authentication first and NTLM second. By default the mod_auth_sspi challenges NTLM first and does not offer Basic Authentication at all.
Locate your section for /svn in the httpd.conf (it should look like this):
Then add or change these two switches in the section to:
See here for their meaning. Make sure to edit the httpd.conf as Administrator (Windows UAC is another PITA). Save the file. Restart the Apache service. Connect to Subversion via your Hudson job. Sm:)e.
NTLM is awkward, if you can avoid it, don't use it! It may even be a security breach when your Apache with mod_auth_sspi serves the internet behind a proxy. If you (or your sysadmins) can't (or won't) bail out Microsoft products consider to use the mod_authnz_ldap from apache with Microsoft Active Directory, since the mod_auth_sspi discussed here seems to be discontinued by the developer(s) since 2006.