Generating a CSR for your Apache Web server is easier than you might think. Once you have the csr generated you can copy and paste the result into your venter’s portal.
To Generate a Certificate Signing Request for Apache 2.x on Centos
- Log in to your server using ssh.
- At the prompt, type the following command:
openssl req -new -newkey rsa:2048 -nodes -keyout [your domain].key -out [your domain].csr
- Enter the requested information:
- Common Name: The fully-qualified domain name, or URL, you’re securing.
If you are requesting a Wildcard certificate, add an asterisk (*) to the left of the common name where you want the wildcard, for example *.coolexample.com.
- Organization: The legally-registered name for your business. If you are enrolling as an individual, enter the certificate requestor’s name.
- Organization Unit: If applicable, enter the DBA (doing business as) name.
- City or Locality: Name of the city where your organization is registered/located. Do not abbreviate.
- State or Province: Name of the state or province where your organization is located. Do not abbreviate.
- Country: The two-letter International Organization for Standardization (ISO) format country code for where your organization is legally registered.
- Open the CSR in a text editor and copy all of the text.
To check the match between a csr, key, and crt file, you can check the output of the following commands
openssl rsa -noout -modulus -in [key file] | openssl md5
openssl req -noout -modulus -in [csr file] | openssl md5
openssl x509 -noout -modulus -in [crt file] | openssl md5
All three commands should output the same string. If they do not, the files are not related.
To check an installed SSL Certificate
https://www.websiteplanet.com/webtools/ssl-checker/
Source: https://www.godaddy.com/help/apache-generate-csr-certificate-signing-request-5269
Source: https://tecadmin.net/check-certificate-private-key-csr-matcher/