howtouselinux

5 ways to check SSL Certificate

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SSL certificates are an important part of online security. They create a secure connection between your website and your visitors, which helps to protect their data. In order to keep your website safe, it is important to make sure that your SSL certificate is up-to-date and working properly. In this blog post, we will discuss five ways to check your SSL certificate.

check SSL certificate with web browser

The easiest way to check your SSL certificate is with your web browser. In most browsers, you can view the SSL certificate by clicking on the padlock icon in the address bar. This will open a new window that displays information about the certificate, including the issuer, expiration date, and more. If there are any problems with the certificate, they will be displayed here.

check SSL certificate with online tools

There are also many online tools that you can use to check your SSL certificate. These tools will provide you with detailed information about the certificate, including any errors that have been found. Some of these tools include:

  • Qualys SSL Labs
  • SSL Checker
  • SSL Certificate Checker

For example:

  • Visit the “SSL Checker” website: https://www.ssllabs.com/ssltest/
  • Enter the URL of the website you want to check in the “Website URL” field
  • Click the “Check” button
  • The SSL Checker will analyze the SSL certificate and report on its status

 

check SSL certificate with openssl x509 command

If you want to check your SSL certificate manually, you can do so by using the openssl command. This command will allow you to view information about the certificate, including the issuer, expiration date, and more. To use this command, you will need to have openssl installed on your computer.

The OpenSSL x509 command allows you to view the details of an SSL certificate. It can be used to view the certificate’s issuer, validity dates, and other information. To use the command, open a terminal and type “openssl x509 -in certificate_file -text”. This will print the text contents of the certificate to the terminal.

You can also use the OpenSSL x509 command to check the expiration date of an SSL certificate. To do this, type “openssl x509 -in certificate_file -checkend N” where N is the number of days in the future you want to check. For example, if you wanted to check if a certificate will expire within the next 30 days, you would type “openssl x509 -in certificate_file -checkend 2592000”.

If you want to view the issuing authority of an SSL certificate, you can use the “-issuer” option. For example, “openssl x509 -in certificate_file -issuer”. This will print the issuer’s name and other information to the terminal.

You can also use the OpenSSL x509 command to check the revocation status of an SSL certificate. To do this, type “openssl x509 -in certificate_file -CRL”. This will print the Certificate Revocation List to the terminal. If a certificate is on this list, it has been revoked and should not be trusted.

The OpenSSL x509 command is a powerful tool that can be used to view the details of an SSL certificate. By understanding how to use this command, you can ensure that your website’s SSL certificate is up-to-date and working properly.

check SSL certificate with openssl s_client command

The OpenSSL s_client command allows you to connect to an SSL server and view the certificate information. It can be used to verify that the SSL certificate is valid and has not been revoked. To use the command, open a terminal and type “openssl s_client -connect server:port”. This will connect to the server on the specified port and print the certificate information to the terminal.

If you want to view the issuing authority of an SSL certificate, you can use the “-showcerts” option. For example, “openssl s_client -connect server:port -showcerts”. This will print the issuer’s name and other information to the terminal.

check SSL certificate with hosting provider

Another way to check your SSL certificate is by contacting your hosting provider. They will be able to provide you with information about the certificate, as well as help you troubleshoot any problems that you may be having.

We hope this blog post has been helpful in showing you how to check your SSL certificate. If you have any questions, please feel free to contact us. Thanks for reading!

David Cao
David Cao

Hey there! I am David, a Cloud & DevOps Enthusiast and 18 years of experience as a Linux engineer. I work with AWS, Git & GitHub, Linux, Python, Ansible, and Bash. I am a technical blogger and a Software Engineer, enjoy sharing my learning and contributing to open-source.