Hi all, this may be a long shot, but I'm looking for someone who can give me a few pointers (if this is better posted to another list, please let me know as well).
TL;DR: I am running into issues with a webdav/caldav client connecting to a Nextcloud instance running on OpenBSD httpd, so someone with a more intimate knowledge of httpd would probably already be a great help. Long story: I have Nextcloud running on my OpenBSD server and have been doing so for several years now without any big issues. Recently, I was trying to connect the caldav client of a SailfishOS smartphone to this Nextcloud instance. As this was failing, I first turned to the Sailfish community, as other caldav clients (e.g. Android ones) connect without problems. One result is that the Sailfish-client seems to work well with other Nextcloud-servers (typically some Apache or Nginx on Linux), so the problem seems to lie somewhere in the interaction between this particular type of client (Qt) and this particular webserver (httpd). Eventually, with the help of one of the Sailfish-community members who is actively involved with the caldav/webdav stuff, I was able to determine that is the initial PROFIND request that already fails. He prepared a little Qt-program for me doing a PROPFIND in the same way as the actual client. In addition, I have created the same in Perl and I've set up a separate test server with a clean OpenBSD 6.8 (by now upgraded to 6.9) install and a fresh Nextcloud 20 installation so I could a) exclude any interference with other things running on my main server and b) experiment freely using plain http. Using this test set-up, I was able observer the same issues as on the main server, which boiled down to the following: - Using the Perl testclient, the PROPFIND always works - Using the Qt testclient, the PROPFIND (almost) always results in a "400 Bad Request" response from httpd, causing the PROPFIND to fail. Using tcpdump on the test server, I was able to determine some differences between the two test clients: The Perl-client seems to send both http-headers and the XML-body for the PROPFIND in one go, gets a 401 response and then re-issues the request with authorisation (which then succeeds). The Qt-client sends the http-headers first in one TCP-segment (I'm not too good on terminology...). Once that has happened, httpd already sends back the 401 - and *then* the Qt-client sends the XML-body in a second TCP-segment, causing the "400 Bad Request" response (I presume because httpd is expecting new headers at this point, not a content body). What I am now trying to figure out (and I neither know the relevant standards nor httpd well enough to do so) is whether this is something weird on the Qt side - or on the OpenBSD/httpd side so I can eventually provide input to the right people to hopefully get this fixed at some point. As mentioned above, any pointers would be greatly appreciated, as this has been bugging me for quite some time now. I have tcpdump traces as well as traces from httpd (which I have recompiled with debugging enabled on the test server) which I can provide. Thanks in advance, Thomas
