Pidgin-sipe failed to authenticate to server while connecting to Office 365

For the last few days, an increasing number of Pidgin-sipe users have been rejected while trying to connect to their Office 365 accounts.

According to the SIPE developers, Lync servers (Office 365) have started rejecting the RC4 stream cipher. Even though it breaks the SIPE plugin, this could be seen as an improvement as Microsoft has recommended to retire RC4 as used in their TLS implementations for years.

Check out the technical details on the SIPE bug tracker: Office365 rejects RC4 in TLS-DSK

Anyhow, the good news is that the SIPE developers have already implemented support for AES-128/256-CBC as mentioned in their changelog:

version 1.20.0 "???" (2015-XX-XX)
- Feature #82: Parse HTML from Lync conference URL (Stefan Becker)
- Feature #69: SRTP Support (Jakub Adam)
  * requires libpurple >= 3.0.0
- Fixed #285: Office365 rejects RC4 in TLS-DSK (Stefan Becker)
  * added support for AES-128/256-CBC

I’ve built the latest snapshot from git and can confirm that the plugin is working as expected on Slackware 14.1 64-bit. Huge thanks and kudos to the SIPE development team for their quick response.

If you cant wait for the next release, then roll your own by grabbing the source from http://repo.or.cz/w/siplcs.git?a=shortlog;h=mob

VirtualBox – Microsoft Lync has stopped working

Skype for Business
It’s not Lync, it’s your shiny new Skype

After upgrading to Windows 10 on a virtual machine running inside VirtualBox 5.0, it became evident that Skype for Business was not gonna to start up as normal without a fight.

Searching through the Windows event log, the most obvious suspect for this failure turned out to be VirtualBox itself:

Faulting application name: lync.exe, version: 15.0.4745.1000
Faulting module name: VBoxD3D9wddm.dll, version: 5.0.0.1573
Exception code: 0xc0000005
Fault offset: 0x00003bb1
Faulting process id: 0x144c
Faulting application start time: 0x01d0de3b5ead5ca2

After upgrading to VirtualBox 5.0.2 and subsequently installing the latest VirtualBox extension pack, Skype started without any further hiccups. Anyhow, VirtualBox doesn’t officially support Windows 10 yet, so some issues are to be expected.

Host setup:
Slackware Linux 14.1 64-bit
VirtualBox 5.0.2

Virtual machine:
Windows 10 32-bit
Skype for Business 2015

The comment section has been closed

To celebrate the landmark of reaching 500k spam posts, I’ve decided to go EOL on the comment section. This decision has nothing to do with any workload of moderating comments as my “no JavaScript support = spambot detected” policy has had a 100% success ratio.

However, running this blog on a Raspberry Pi 2 means that disabling the comment section will put less strain on the PHP interpreter and thus makes a welcome optimization for this site.

In my experience, only a few readers will actually comment on posts (which is perfectly acceptable) so I don’t think I’m taking away a feature that will be largely missed.

If you want to join the fight against spammers, then I’ll ask you to consider joining Project Honey Pot by clicking the link below:

Stop Spam Harvesters, Join Project Honey Pot

Note: the link contains a referrer which will let me know if someone joined the project by using my referrer. Feel free remove it if you so prefer.