How To: Create Self-Signed Certificate – OpenSSL

What is a self-signed SSL certificate? A self-signed certificate is a certificate that is not signed by a trusted authority.

Nevertheless, the self-signed certificate provides the same level of encryption as a $100500 certificate signed by a trusted authority.

In this article i will show how to create a self-signed certificate that can be used for non-production or internal applications.

Cool Tip: Check the expiration date of the SSL Certificate from the Linux command line! The fastest way! Read more →

Create Self-Signed Certificate

Generate self-signed certificate using openssl:

$ openssl req -x509 -newkey rsa:4096 -keyout key.pem -out cert.pem -nodes -days 365 -subj '/CN=localhost'

Options that you might want to change while creating a self-signed certificate:

-newkey rsa:4096 Generate a 4096 bit RSA key.
-keyout key.pem Save a key to the key.pem file.
-out cert.pem Save a certificate to the cert.pem file.
-nodes Do not protect the private key with a passphrase.
-days 365 The number of days to make a certificate valid for.
-subj '/CN=localhost' Use this option to suppress questions about the contents of the certificate. Replace localhost with your desired domain name.
0 (0)
Article Rating (No Votes)
Rate this article
There are no attachments for this article.
There are no comments for this article. Be the first to post a comment.
Full Name
Email Address
Security Code Security Code
Related Articles RSS Feed
RHEL: Back-up/Replicate a partition table
Viewed 1439 times since Sun, May 27, 2018
How To Use the Linux Auditing System on CentOS 7
Viewed 1231 times since Fri, Apr 5, 2019
Expand or grow a file system on a Linux VMWare VM without downtime
Viewed 837 times since Fri, Jul 27, 2018
CentOS / RHEL : Configure yum automatic updates with yum-cron service
Viewed 2513 times since Fri, Oct 26, 2018
How to Analyze or Read OS Watcher Output in three easy steps -- With Example ?
Viewed 5499 times since Thu, Jun 21, 2018
RHEL: Change system’s hostname
Viewed 1426 times since Sun, May 27, 2018
Check a Website Availability from the Linux Command Line
Viewed 675 times since Mon, Feb 18, 2019
Tunnel SSH Connections Over SSL Using ‘Stunnel’ On Debian 7 / Ubuntu 13.10
Viewed 1025 times since Fri, Sep 28, 2018
Top 25 Best Linux Performance Monitoring and Debugging Tools
Viewed 3708 times since Sun, Sep 30, 2018
tcpdump usage examples
Viewed 773 times since Fri, Jul 27, 2018