How to modify SVN errors in Ubuntu

Subversion & Certificate problems with Ubuntu precise pangolinwednesday, May 2. 2012

For quite a while the Ubuntu subversion package suffer from bad user certificates that do not follow the standards strictly. In case you have to authenticate with such a certificate subversion will return such an error message:

OPTIONS of '<url>': SSL handshake failed: SSL error: Key usage violation in certificate has been detected. (<url>)

The root of this problem is that the Ubuntu packages link against
Libneon-gnutls, which handles certificates in a stricter way
Libneon.
Easy workaround in the past was to simply replace a Replace the Library Link
Libneon-gnutls to point
Libneon:

sudo mv /usr/lib/libneon-gnutls.so.27 /usr/lib/libneon-gnutls.so.27.old
sudo ln -s /usr/lib/libneon.so.27 /usr/lib/libneon-gnutls.so.27

However once you do this in Ubuntu 12.04 precise pangolin you will get a another error message instead:

OPTIONS of <url>': SSL handshake failed: SSL disabled due to library version mismatch (<url>)

After quite some Googling it turned out that there is a bug in the version
Libneon bundled with precise that causes this problem. Fortunately this is already fixed with version 0.29.3. To get back to a working subversion perform these steps:

1. Uninstall the current
   Libneon package:
   sudo apt-get remove libneon27>
2. Download the latest libneon
   Package from http://packages.debian.org/squeeze/libneon27 (at the bottom you can choose the right version for your architecture ).
3. Install the required libssl dependency:
   sudo apt-get install libssl0.9.8
4. Install the downloaded
   Libneon package. e. g. for the 64bit architecture:
   dpkg -i libneon27_0.29.3-3_amd64.deb
5. Change the symbolic links again like described abve:
   sudo mv /usr/lib/libneon-gnutls.so.27 /usr/lib/libneon-gnutls.so.27.old
sudo ln -s /usr/lib/libneon.so.27 /usr/lib/libneon-gnutls.so.27

And finally subversion shocould be working again.