Friday, March 25, 2016

How to make Firefox more secure in a few clicks

I've messing a lot with cipher suites lately and something I always do in my firefox browsers will stop all the non forward secrecy ciphers.

What Forward Secrecy does is use a second dynamic key when encrypting your traffic. So even if the bad guys break a private key on your server's certificate at the later date your traffic is encrypted by another layer.  If you don't use forward secrecy and they capture your data and find the private key it's easy to decrypt. Wireshark will do it on the fly.

So in Firefox

type about:config in the address bar



It will bring up a warning saying be careful.  Click yes you know.

In the search box below the address bar type ssl.  Look at the bottom of the list and find the ones that start security.ssl3.rsa and double click them and will change enabled to false. You should also disable anything that mentions rc4.  The ones that have dhe are good, the ones that have ecdhe are better, and the ones that have chacha20 are best but not everything supports them.




Try you websites and you might need to re-enable some if, say your bank doesn't work.  Alternatively run your bank against this site

https://www.htbridge.com/ssl/

and let them know if they don't get a good score.

Tuesday, March 15, 2016

Linux Kernel 4.5 and amdgpu

My Linux gaming experience has been a bit sub par since upgrading to a Radeon R9-380.

It was just laggy enough to make playing hard. You often don't see the person that's killed you and things like air blasting rockets in TF2 was almost impossible to time right.

However things seems to have turned.  With Kernel 4.5, the amdgpu driver and adding the amdgpu.powerplay=1 to your kernel options in GRUB speed of gaming and even YouTube is quite noticeably improved.

The other problem I had been having was TF2 would freeze after a few games and you had to do the old alt prt-sc REISUB to reboot. Touch wood that also seems to be fixed.

So a big debt of thanks to the Kernel team and particular the amdgpu guys.


Friday, December 18, 2015

Windows 10 stalling with 100% disk active time but read and write 0 KB/s

I gave Windows 10 another try tonight and after some pretty hefty updates I still have the same issues as before.  Same hardware on Windows 8.1 didn't do this.

This is the Task Manager when it happens:  100% disk usage, 0 ms response time,  but 0Kb/s in and out and it happens for over 35 seconds. The whole system just stops for just about everything. Programs that are completely loaded and don't access disk are fine. (i.e Task Manager) Not so good when gaming though.

Someone else must be seeing this I'm hoping and maybe have a solution.  I've read of some others seeing it but also the same issues in 8.1 so maybe I was lucky not to get it then. 




Update 29/12/15  I had another look at this over the Christmas break and may have made some progress. I downloaded the driver for the AHCI for the nForce controller on this motherboard and it seems to be better (touch wood)

I wouldn't install the whole package of drivers but I downloaded the Vista 64 bit drivers (Windows 7 64 bit showed no downloads for some reason) and updated from device manager the storage controller and in a few hours testing no more 100% active 30 second lock ups. Far from conclusive but hopeful.

So yes it's an old board but there's bound to be others with the same or similar issue. The nForce storage driver in windows 10 looks a bit broken.

Saturday, November 21, 2015

OSX high CPU UserEventAgent process

This one might save someone some searching :-)

I can't remember when it started happening but the UserEventAgent process started using 90 to 90% CPU so basically stealing one core all the time.

I thought it was related to a whole lot of things that turned out to be red herrings.

In my case it was TeamViewer causing it.  Uninstall TeamViewer and it spikes but generally sits at 0% rather than 95%.

Some Googling found one particular plug in related to certificate verification that the UserEventAgent uses caused their high CPU usage so maybe some Apps just make it go nuts.

Saturday, November 7, 2015

Upgrading the SD Card on a Raspberry Pi

Well this turned out to be a whole lot easier than I thought :-)

I had an old card from a version 1 Raspberry Pi and had just moved it to a version 2 board. It's a little mail, DNS etc server and stalls occasionally especially when fail2ban is starting as that goes through all the syslogs etc looking for failed logins.  Top showed way too much waiting for disk time so it was time to investigate.

I brought a new SDCard (bigger was my first goal as mail expands) and an SDCard reader and started playing.  Well, boy is SDCards one of those things you don't know what you don't know. It's just a little card you chuck in your phone or camera?  No way.

There is so much forwards, backwards compatibility and huge variations in speed.

I bought a MicroSD HC UHS class 3 card. Benchmarking showed this seemed to be limited by USB2 speed but was already three to five times faster than the old card but would the Ra Pi read it?

The easy part was moving the data from the old card to the new one.  There are 3 partitions (well 3 actual,  4 logical) on the old card. Oddly you have

RECOVERY a 1.5 GB fat32 partition then
and extended partition that has
BOOT a 64MBish fat32 logical partition and
root a 6GB ext4 logical partition and
SETTINGS a small ext4 partition.

They could have avoided using logical partitions all together but I guess it give easy expansion.

The actual transfer from the old card to the new card was as easy as mounting both, starting GParted and copy and paste the partitions.  That is a fantastic piece of software. Literally right click, copy from /dev/sde and paste /dev/sdf and adjust the size of the root partition to use the rest of the free space and it's done.

Plugged the card into the Raspberry Pi 2 and started it up.  Looked good! The disk light flashed and it seemed to boot.  The access seemed briefer if that is the right word.  It used to flash and stay on a few seconds at a time during boot but it was less than a second for each pulse now.

By the time I logged in (it's headless in the garage so this is about 1 minute later)  it had started and fail2ban had started so it was way quicker.

This is all anecdotal but it feels quicker and the Ra Pi 2 seems to be happy with the new cards.  I'm not sure how much the Ra Pi wears an SD card so replacing them every so often seemed sensible.


Saturday, October 31, 2015

Video card upgrade time

I thought it was time to upgrade the old video card which was a Power Color ATI 5770 1GB.

I had a bit of a look around and thought I'd stick with AMD/ATI which may or may not be wise but I know the issues I've had and resolved with ATI.

I looked through the support forums and settled on an R9 380 2GB from ASUS. It seems to be well supported in the latest kernels and they've developed an new driver (amdgpu vs radeon) so I'd imagine it's going to get way better over the next few months.

It plugged in easily enough (double slot sized card) and first thing you notice is this is quiet.  The 5770 was noisy at idle and very noisy when playing games. I've only played TF2 but I can't even hear if the fan on the video card is going over the CPU fan now. The CPU fan is an Arctic Ice one so it larger and slower than standard and so usually pretty quiet. Downside is TF2 was more slightly choppy than it had been on the 5770 so it looks they still have some optimising to do but this is early releases of the driver for kernel and xorg.  OpenGL is now 4.1 from 3.3 with the old card so more games work.

On Gentoo you add radeonsi and amdgpu to the VIDEO_CARDS list in make.conf and do a emerge -DuN @world to update Mesa, xorg drivers etc. emerge the amdgpu-ucode files and add them to the kernel and you're done.

I'll add more as I play more and as new drivers come out but so far it works and is quick enough to play games and has plenty of potential to improve.

Saturday, September 5, 2015

Mincraft Gentoo 64 bit

I recently upgraded to Gentoo 64 bit and generally it's been great.  Dropped LVM and just used partitions at the same time and it feels generally a bit quicker. A few issues with Steam but they've been resolved in another post.

Minecraft was the one thing that still didn't work.

It needed one extra install to make it work.

emerge x11-apps/xrandr

Once this was installed it worked fine otherwise it crashes with errors like:

OpenGL: ~~ERROR~~ RuntimeException: No OpenGL context found in the current thread.