Showing posts with label OS. Show all posts
Showing posts with label OS. Show all posts

June 09, 2022

Generate Free SSL HTTPS Certificates with 90 days validity using letsencrypt

 Hi all,

As discussed in my earlier blog, Generate Free SSL Certificate using ZeroSSL where the limitation of one free certificate on ZeroSSL can be eliminated using Get HTTPS for free!

This process includes the following prerequisites and procedures.

Note: This process is not for beginners or production usage scenarios. Use this process if you are knowledgeable about certificate generation.

Prerequisites

  • OpenSSL command line
  • [Li]nix / Mac OS

Procedure

  • Open the URL https://gethttpsforfree.com
  • It has 5 steps
    • Account Info
    • Certificate Signing Request
    • Sign API Requests
    • Verify Ownership
    • Install Certificate
  • In each step, some commands or processes need to be followed to get the free SSL certificate.

  1. Account Info
    1. In this step, we will be providing the email and public key.
    2. Keep the generated private key security in your system.
      • Note: If you are unsure about the public key generation commands, click on the "how do I generate this?" link, which is available over the public key input textbox.
  2. Certificate Signing Request (CSR)
    1. Generate the CSR for the required domains
      • Note: You can generate the CSR for wildcard certificates and www subdomain with the same command
    2. Try to follow the same format, including the line feeds mentioned below.
    3. #change "/etc/ssl/openssl.cnf" as needed:
          #  Debian: /etc/ssl/openssl.cnf
          #  RHEL and CentOS: /etc/pki/tls/openssl.cnf
          #  Mac OSX: /System/Library/OpenSSL/openssl.cnf
      
          openssl req -new -sha256 -key domain.key -subj "/" \
            -reqexts SAN -config <(cat /etc/ssl/openssl.cnf \
            <(printf "\n[SAN]\nsubjectAltName=DNS:foo.com,DNS:www.foo.com")) 
  3.  Sign API Requests
    1. Sign all the requests with the private key
    • Note: You need to copy the command and execute it on your PC/Mac terminal, and the result needs to be pasted on the web page.
  4. Verify Ownership
    1. In this step, you need to prove your domain ownership
    2. You will be given 3 options
      1. Python server
      2. file-based
      3. DNS record (I've used this option)
        1. Update the DNS records with new TXT entries, and use the online dig tool to make sure the records are visible.
        2. After we verify the availability of the records, you need to click on the respective buttons on the web page.
    3. Repeat the same steps for each domain on CSR (www and any sub-domains).
  5. Install Certificate
    1. You will be able to receive your certificate in "chained.pem" format
    2. Copy and paste the first certificate section (e.g. the first "-----BEGIN CERTIFICATE-----" section) into a text file named "domain.crt".
    3. Copy and paste the second certificate section (e.g. the second "-----BEGIN CERTIFICATE-----" section) into a text file named "intermediate.pem".
    • Note: Expand the "how do I install this?" link for quick help.
Hope this will help you to generate free SSL for your websites.

Request you to send your valuable feedback and comments to psrdotcom@gmail.com

November 17, 2021

Extend Ubuntu VM hard disk space/size

 Hi all,


Today I will explain about the process to extend and existing disk space in Ubuntu VM.

Environment

  1. VMWare
  2. Ubuntu

Context

Increase hard disk space more than initially configured for the Ubuntu VM.

Reason

VM hard disk might running out of space.

Procedure

  • Make sure we have shutdown the Ubuntu VM
  • Increase the hard disk size
    • Make sure it's in the allowed range
  • Start the VM
  • Open the Disks application in Ubuntu
  • In below example we are extending it by additional 3GB
  • Select the Extended Partition block
  • Click Settings (Gear) icon
  • Choose Resize option
  • Use the increment (+) icon or scroll bar to increase the partition size
  • Click on Resize button
  • Enter credentials when prompted
  • By now, the extended partition will be increased
  • Time to select the file system, where exactly our data is getting stored
  • We will repeat the process of resizing like earlier
  • Using scrollbar increase the disk size
  • Click on the Resize button
  • The harddisk size is been reflected.
Hurray !! You have increased your hard disk size to store more data on the Ubuntu VM.

The same process can be used for normal Ubuntu OS also.

Please send your comments and feedback to psrdotcom@gmail.com

August 22, 2015

Ubuntu Windows dual boot order changes GRUB

Hi friends,

From long time, I was thinking of modifying my default boot option to Windows instead of Ubuntu. Finally today, I've done those changes in my laptop.

My system has Windows 10 and Ubuntu 14.04 dualboot and Ubuntu OS is my default boot option with 10 seconds timeout.

I thought of sharing the information with everyone.

Please open the terminal and run the followin commands in sequence 
  1. sudo add-apt-repository ppa:danielrichter2007/grub-customizer
  2. sudo apt-get update
  3. sudo apt-get install grub-customizer
By now, grub-customizer will be successfully installed in your PC.

Please follow the below step to do the necessary changes in boot order

  • Open the grub-customizer
 

  • Grub customizer lists the installed OS with versions
 

  • Rename the OS entry by right clicking and selecting "Rename" option [Optional]
 

  • Choose the default boot option by navigating to "General Settings"
  • Select options from "predefined" entry


  • Click on "Save" option to save all the changes.
  • You can revert the changes by clicking the "Revert" option, if you feel like going back to original/initial options

Hope it would help you in changing the default boot order

Please send your comments and feedback to psrdotcom@gmail.com

August 15, 2014

Android L Preview on Nexus 7

Hi all,

Today I’ve finally loaded the Android L Developer Preview on my Nexus 7 Wi-Fi 32GB

 

Its so simple to load the Android L. Here is the procedure

 

Warning

All the device data will be erased. Please take backup of all your data before doing this upgrade.

Not all the applications will work since it’s just a developer preview OS version

 

Pre-requisites

  • Android SDK with latest update
  • Android L Preview OS image
  • Make sure that, your device has more than 60 to 70 percent of battery
  • Enable USB Debugging
  • Connect the device to computer with USB cable. Make sure that, it has detected by computer

 

If you don’t’ have the pre-requisites, please follow the below procedure

 

Android SDK Installation & Update

  1. Download the Android SDK from this link
  2. https://developer.android.com/sdk/index.html
  3. Open SDK Manager.exe
  4. Install Tools, Android L Preview, Extras
  5. Update latest version if available

 

Android L Preview OS Image Download

  1. Download the corresponding Android L OS image for your device from this below link

 

Installation Process

  1. Extract the downloaded image to a folder
  2. From Android SDK folder, navigate to “platform-tools” folder, copy adb.exe, AdbWinApi.dll, AdbWinUsbApi.dll and fastboot.exe
  3. Paste in the Android L Preview extracted folder
  4. Finally the extracted folder should look like this
    • image
  5. The highlighted files has been copied from SDK->platform-tools folder
  6. Open the command prompt and navigate to OS extracted folder
    • Tip
      • Open the folder in explorer window. Hold “Shift” and right click on mouse
      • Select “Open command Window here” option
  7. Connect the device to computer
  8. Put device into “fastboot” mode by rebooting
    • cmd> adb reboot fastboot
  9. Device gets rebooted to fastboot
  10. If device is locked, then please unlock it
    • cmd> fastboot oem unlock
  11. Now, run the “flush-all” script
    • cmd> flush-all
  12. It takes some time to install the image
  13. After completing the installation process, it asks you to press “enter/return” button to exit
  14. Press enter/return button for confirmation
  15. Device gets restarted, Android L Preview will be displayed on the device
  16. To lock the device, execute following commands
    • cmd> adb reboot fastboot
    • cmd> fastboot oem lock
  17. Like a new device, enter all the details like your Gmail account, Wi-Fi connection etc.
  18. Enjoy the features of Android L Developer Preview OS

 

Please send your feedback and queries to psrdotcom@gmail.com
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