Hidden Lead Bytes in Thumbprint while copying from Windows

Posted on by Allen

Microsoft digs lots of pits, and I keep jumping among them.

Recently, I wrote a program using HttpClient in dotNet to post some data to server through HTTP Post. The server is set with client certificate required.

My designing is simple:

  1. Open X509Store to query the certificate by using thumbprint.
  2. Attach the certificate found in step 1 into WebRequestHandler.
  3. Pass the handler created in step 2 to the instance of HttpClient and send the request.

Required by step 1, I need to type the thumbprint of the certificate into code. The steps I did:

  1. Open certificate from Windows. It’s shown up like this:
  2. Copy the text of Thumbprint and paste it into a notepad.
  3. Replace all spaces to nothing.
  4. Copy the new text into code.

When I run the code, it ended in a strange way. No certificate is found by using the thumbprint I provided. I dig a long time before I found this pit prepared by Microsoft:
The text, copied from the window above (in step 1), contains hidden lead bytes “0x200E”. These bytes won’t display in code view of Visual Studio, nor in Notepad.

After these removed, problem is gone as well.

Php upgraded to 7.1 while Ubuntu 17.10 upgrading process

Posted on by Allen

If you need to upgrade a Ubuntu with LAMP from 17.04 to 17.10, you need more time due to php upgrading.

Php 7.1 will be installed to replace 7.0. Lots of mods, as well as fpm, need to be reconfigured.

(:з」∠)

ShortUrl

Posted on by Allen

ShortUrl

Short url generator with no database required. Install this as a site.

Language: C#
Platform: ASP.Net 4.0

Source files available at https://github.com/scegg/ShortUrl/.

License: MIT

dotNet Standard sucks…

Posted on by Allen

While you using netstandard to write a solution about type, assembly, roslyn and so on, you will find there is no standard at all.

netstandard is not a standard of dotnet. It’s just another standard with all others.

Fix Ubuntu Server bash for internet accessing (DNS querying)

Posted on by Allen

I have multiple devices installed with Ubuntu Server. Some of them have a strange problem:
They can access internet using some applications, such as squid, without any problem.
They can ping to internet IP address.
They can use host / dig to query IP by domain name.
They cannot ping to internet by using domain name directly.
They cannot download file through wget / curl using domain name, but can do with IP.
They cannot use apt, stuck at connecting.
All they use a local dnsmasq as their dns.

After a long time dig, I found the problem and here is the fix.
open the file /etc/nsswitch.conf, search the line with “hosts:” and change the setting to “files dns” (without quotes).

Web Deploy for Visual Studio

Posted on by Allen

While I’m trying to deploy my site from Visual Studio to a Windows Server 2012 R2 instance, I have to dig a lot for troubleshooting about Web Deploy related problems.

 

Here are some not listed in Microsoft documents:

  • Visual Studio need both Web Deploy (Web Deployment Agent Service, MsDepSvc) and Web Management Service (WMSVC).
  • You cannot install Web Management Service separately.
  • The easy way to install the both is choose “Web Deploy 3.6 for Hosting Servers” Web Platform Installer.
  • If you selected “Web Deploy 3.6” in another release, without “for Hosting Servers”, Web Management Service will not be installed.
  • If you leave Web Deploy installed without Web Management Service, you could add it by install “Web Deploy 3.6 for Hosting Servers” but IT WILL NEVER WORK! You have to UNINSTALL existed Web Deploy first and then reinstall the “Web Deploy 3.6 for Hosting Servers”.

Install ubuntu server into Soekris net6501 by using USB boot

Posted on by Allen

This will guide you to prepare a installation media from Windows and install ubuntu into Soekris net6501.

Stuffs you need:

  • a USB stick that CAN BE RECOGNIZED by net6501 device.
    Not sure? Attach it to net6501 and reboot. If you can read the SIZE of this stick while booting, it is.
  • an ISO file for ubuntu server 32-bit. Version 16.10 is tested.
  • rufus. Guide and download point at https://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows.
  • a working serial connection from your workstation to your net6501, software included.

Prepare installation media:

  • Use rufus to build the USB stick. Check the guide above.

Install:

  1. Link net6501 to your computer using serial connection and start the link. In this case, I’m using the default setting (Speed=19200, Data bits=8, Stop bits=1, Parity=None, Flow control=XON/XOFF).
  2. Boot your net6501 with USB stick attached.
  3. Hit ctrl-p to go into bios.
  4. Type “boot 81” (without quotes) and press enter to boot from USB.
  5. You will see that something wrong with gfxboot.
  6. Type this text below SLOWLY and press enter. DO NOT COPY AND PASTE:
    install console=ttyS0,19200
  7. Do not press any key related to screen mode selection. It will be passed.
  8. Choose a language and continue installation steps as normal.

Finalize:

Grub configuration need to be adjusted for using serial as console.

Edit /etc/default/grub and change to these lines below:
GRUB_CMDLINE_LINUX_DEFAULT="quiet"
GRUB_CMDLINE_LINUX="console=ttyS0,19200 noplymouth"

Then run update-grub.

 

Hope this help you.