How to Check CentOS Version From Command Line

lsb Command to Display Details of CentOS Linux Release

LSB (Linux Standard Base) is a joint project of several Linux distributions to standardize software system structure. One of the commands available from the command line lsb_release. The output will indicate which OS version you are running.

1. Before you can use lsb commands, you have to install the package first. Use the following command:

# sudo yum install redhat-lsb-core 

2. Type in your sudo password to authorize the installation and then press Y and Enter to confirm.
3. Once you have installed it, you can check your CentOS/REHL version as shown with the command:

# lsb_release -d 
or
# lsb_release -a



Find CentOS Version with the hostnamectl Command CentOS version 7 and next distributions, 
hostnamectl command is used to query and set Linux system hostname, and show other system related information, such as operating system release version 
It displays information from the 
/etc/centos-release file, 
uname –a file and others. 
In addition to version number, it indicates which Linux kernel your system is using. 
To see these specifics, use the command: 
# hostnamectl



Find CentOS Version with RPM - RPM (Red Hat Package Manager) is a popular open-source and core package management utility for Red Hat based systems like (RHEL, CentOS, Fedora). 
With the rpm command, you can find out the full package name and the release version of CentOS you are running. 
Use the command: 
# rpm –qa centos-release 
or
# rpm -ql centos-release | grep release$
or
# rpm -qf /etc/redhat-release


Check CentOS Version in Release File To check which Linux distro and major release version you have installed, 
open the release file using the command: 
# cat /etc/os-release 
The output reveals the name of the operating system, its major release version, 
and other specifics, as displayed in the image below.

Check Linux Kernel Version in CentOS Knowing the kernel version you are running is often as useful as finding the release version. 
Find out which Linux kernel version you running, with the command: 
# uname –r 
or 
# uname -s -r
The output you receive is the version number of the kernel of your operating system.

The 4 files shown below provides the update version of the CentOS/Redhat OS.
/etc/centos-release 
/etc/os-release 
/etc/redhat-release 
/etc/system-release

Error HRESULT: 0x80070520 when adding SSL binding in IIS

Error There was an error while performing this operation

Details:

A specified logon session does not exist. It may alredy have been terminated. (EXception from  HRelult: 0x80070520)

you can use the option to generate a certificate:

openssl pkcs12 -export -out domain.name.pfx -inkey domain.name.key -in domain.name.crt

The key file is just a text file with your private key in it.

If you have a root CA and intermediate certs, then include them as well using multiple -in params

openssl pkcs12 -export -out domain.name.pfx -inkey domain.name.key -in domain.name.crt -in intermediate.crt -in rootca.crt

If you're looking for a Windows graphical user interface, check out DigiCert. It is a fairly simple program with an easy interface.

On the SSL tab, import the generated certificate. Then, after selecting the Certificate, you can export the file as PFX with or without a key.
https://www.digicert.com/util
This program can also repair a certificate that was uploaded with an error

How to create .pfx file from certificate and private key?

1. Open web page - 

2. Select Type of Current Certificate

Your certificate should be issued in Standard PEM format. Common PEM extensions include .cer, .crt, and .pem. Make sure Type of Current Certificate is set to “Standard PEM”.

3. Select Type to Convert To

Select “PFX/PKCS#12” as the Type to Convert To.

4. Upload Certificate

Locate Certificate File to Convert and click the Choose File button to upload your certificate. This file should be the certificate that is issued to your web server domain.

5. Upload Private Key

Locate Private Key File and click the Choose File button to upload the file. 

6. Upload Chain Certificate Files

Locate Chain Certificate File and click Choose File to upload the CA intermediate certificate. The appropriate certificate depends on what brand of SSL you have, so please make sure you have the correct intermediate certificate before you upload your file.

8. PFX Password

Create a new password for your PFX file. You will need to remember this password when you install the PFX file on your system.

9. Convert Certificate

Once you have uploaded the certificate and key files, click the Convert Certificate button to complete the process and download your new PFX file.