I just installed StartSSL SSL certificate into owncloud plugin.
1. Get FQDN for your OwnCloud plugin. FQDN is required for proper SSL certificates.
2. Get certificate, private key and intermediate certificate into /usr/pbi/owncloud-amd64/etc/apache22 (I think you need intermediate to get free StartSSL and Firefox play nice togheter)
3. Changed /usr/pbi/owncloud-amd64/etc/apache22/extra/httpd-ssl.conf to match certificate files
After this tested first time, HTTPS worked fine but got that same WebDAV error.
4. Add your FQDN to OwnCloud jail /etc/hosts file and point to your OwnCloud jail IP. This is because OwnCloud couldn't resolve the FQDN properly (because it was pointing into WAN IP and not NATed IP of OwnCloud plugin)
After this no more WebDAV errors.
So I haven't changed hostname settings and I don't have FQDN defined in Apache settings.
Important thing is that when you connect to your OwnCloud with HTTPS, address you use to connect needs to match to Common Name of certificate. The matching is done at client side, not server. And I think WebDAV tries to use the same address you are using to make loopback connection somewhere else (?) and if server does not resolve it back to right IP, it fails.
1. Get FQDN for your OwnCloud plugin. FQDN is required for proper SSL certificates.
2. Get certificate, private key and intermediate certificate into /usr/pbi/owncloud-amd64/etc/apache22 (I think you need intermediate to get free StartSSL and Firefox play nice togheter)
3. Changed /usr/pbi/owncloud-amd64/etc/apache22/extra/httpd-ssl.conf to match certificate files
After this tested first time, HTTPS worked fine but got that same WebDAV error.
4. Add your FQDN to OwnCloud jail /etc/hosts file and point to your OwnCloud jail IP. This is because OwnCloud couldn't resolve the FQDN properly (because it was pointing into WAN IP and not NATed IP of OwnCloud plugin)
After this no more WebDAV errors.
So I haven't changed hostname settings and I don't have FQDN defined in Apache settings.
Important thing is that when you connect to your OwnCloud with HTTPS, address you use to connect needs to match to Common Name of certificate. The matching is done at client side, not server. And I think WebDAV tries to use the same address you are using to make loopback connection somewhere else (?) and if server does not resolve it back to right IP, it fails.