Category Archives: Howto

Client-side SSL

Posted on by
Reply

Client-side SSL

For excessively paranoid client authentication.

Using self-signed certificate.

Create a Certificate Authority root (which represents this server)

Organization & Common Name: Some human identifier for this server CA.

openssl genrsa -des3 -out ca.key 4096
openssl req -new -x509 -days 365 -key ca.key -out ca.crt

Create the Client Key and CSR

Organization & Common Name = Person name

openssl genrsa -des3 -out client.key 4096
openssl req -new -key client.key -out client.csr
# self-signed
openssl x509 -req -days 365 -in client.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out client.crt

Convert Client Key to PKCS

So that it may be installed in most browsers.

openssl pkcs12 -export -clcerts -in client.crt -inkey client.key -out client.p12

Convert Client Key to (combined) PEM

Combines client.crt and client.key into a single PEM file for programs using openssl.

openssl pkcs12 -in client.p12 -out client.pem -clcerts

Install Client Key on client device (OS or browser)

Use client.p12. Actual instructions vary.

Install CA cert on nginx

So that the Web server knows to ask for (and validate) a user’s Client Key against the internal CA certificate.

ssl_client_certificate /path/to/ca.crt;
ssl_verify_client optional; # or `on` if you require client key

Configure nginx to pass the authentication data to the backend application:

Using CACert Keys

 

 

Original posting: https://gist.github.com/mtigas/952344#client-side-ssl

IMPASSA Self-Contained 2-Way Wireless Security System (model SCW9057)

Posted on by
Reply

This wireless security system is widely used by ADT and companies providing security.

Useful links:

IMPASSA Self-Contained 2-Way Wireless Security System

DSC – IMPASSA Self-Contained 2-Way Wireless Security System – User Video English

DSC IMPASSA 2 Way Wireless Security System

How to Change Master and User Code on DSC Powerseries

How to Program DSC Neo Proxy and PG9939 Keyfob

Default master/installer code

The default code is 1234 or 5555.

It might be changed on your system and if you make few wrong attempts the keyboard will be locked temporarily.

How to reset to factory settings

If you do not have the master code or installer code you are limited in what you can do with the system.

You can do a factory reset and will be able to set your own master code.

NOTE: If you do a factory reset all settings will be lost including any zones, sensor information, etc.

To do a factory reset do the following:

  • turn the AC power off (unplug the transformer)
  • open the front panel (check the user manual on how to do it) and disconnect the battery pack
  • connect IO1 and IO2 with a wire
  • Power the device with AC only. Keep it power for 10 to 20 seconds
  • Power off the device
  • remove the wire between IO1 and IO2
  • connect the battery
  • Turn the AC power on

Now you device is factory reset. You need to configure everything including set the date and time.

The default master/installer code is 1234

Programming

If you have the master/installer code you can do things like

  • adding a new user code for a family member or the cleaning lady
  • adding new sensors
  • programming new wireless remote

Add new user

[*][5] [1][2][3][4]  [<][>]     [*]               [9][7][1][3]     [#]
       master code   select user      to access code    new user code    exit

Delete user

[*][5] [1][2][3][4]  [<][>]     [*]               [*]      [#]
       master code   select user      to access code    delete   exit

Letsencrypt + Certbot

Posted on by
Reply

Letsencrypt provides free SSL certificates

Certbot automates re-newal and installation of the certificates

Install Certbot:

$ sudo add-apt-repository ppa:certbot/certbot
$ sudo apt-get update
$ sudo apt-get install python-certbot-apache

Generate and install the certificate

$ certbot --apache

Generate the certificate only

$ certbot --apache certonly

Generate wildcard certificate

$ sudo certbot certonly --manual --preferred-challenges=dns --email yourname@yourdomain.com --server https://acme-v02.api.letsencrypt.org/directory --agree-tos -d *.yourdomain.com

Renewal

The Certbot packages on your system come with a cron job that will renew your certificates automatically before they expire. Since Let’s Encrypt certificates last for 90 days, it’s highly advisable to take advantage of this feature.

$ sudo certbot renew --apache

[XPS 15 9560/Precision 55520] FIX for Lag/Stuttering on Kaby Lake

Posted on by
50

I bought a Dell XPS 15 9560 recently and after setting it up and updating all drivers, etc. I noticed there was a lag/stuttering when using Google Chrome browser.

It turns out I was not alone – apparently many people noticed the same problem. I came across this reddit thread which helped me to fix the issue: [XPS 15 9560/Precision 55520] FIX for Lag/Stuttering on Kaby Lake

The problem seems to be a buggy driver for the Intel HD Graphics 630 display adapter.

The most current version (as of the time of writing) on the Dell web site is version 21.20.16.4574

In order to fix the problem you need to download version 21.20.16.4590 from the Intel’s web site: Intel® Graphics Driver for Windows [15.45.14.4590]

EDIT (17 April 2017): You should see a yellow banner on Intel’s site saying there is a newer version of the driver:

It is version 15.45.16.4627 and it is working fine on the same computer I installed 4590 before. You may wanna use the newer one. The steps below are the same regardless if you use 4627 or 4590.

There is .exe and .zip file. Download the .zip file and save it on your disk. Extract the files.

Right-click the start button and run Device Manager:

Expand the Display Adapters, right-click Intel(R) HD Graphics 630 and select Update Driver Software…

Important: In the dialog below do not click Next or Browse. Instead click on Let me pick from a list of devices on my computer.

You will see a list of devices. This just shows the graphic card and what drivers are installed. You may have more than one driver installed for the same graphic card. This is normal – when a newer version is installed the old one is kept so you can revert back to an older driver if you want.

Important: The picture below shows one of the items selected – this was my mistake. You do not have to select one. Just click Have Disk… to continue.

Navigate to the folder where the drivers were unzipped. Open the Graphics folder. In my case the full path is C:\Users\Vicki\Downloads\win64_154514.4590\Graphics

There should be an .inf file. Select it and click Open.

This should start the installation. After it is complete verify the driver has version 21.20.16.4590.

Note: The steps might be different for you since I took the screen-shots after I had the new driver installed.

The important part is to not click Next but to choose Let me pick from a list of devices on my computer as mentioned earlier.

This seems to fix the lag/stuttering I was experiencing. I hope this works for you too.

Ubuntu updates via command line

Posted on by
Reply

Update:

sudo apt-get update        # Fetches the list of available updates
sudo apt-get upgrade       # Strictly upgrades the current packages
sudo apt-get dist-upgrade  # Installs updates (new ones)

Clean up the system from old packages:

sudo apt-get update && sudo apt-get autoclean && sudo apt-get clean && sudo apt-get autoremove

Check the Ubuntu version:

lsb_release -a

Force Apt-Get to IPv4 or IPv6 on Ubuntu or Debian

Posted on by
Reply

You can force IPv4 with:

apt-get -o Acquire::ForceIPv4=true update

or IPv6:

apt-get -o Acquire::ForceIPv6=true update

To make this persistent,check this post out:

https://www.vultr.com/docs/force-apt-get-to-ipv4-or-ipv6-on-ubuntu-or-debian

How to install Mono on Ubuntu

Posted on by
Reply 
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF

echo "deb http://download.mono-project.com/repo/debian wheezy main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list

sudo apt-get update

sudo apt-get install mono-runtime