Most SSL distributors will ask for a CSR when you try to purchase a certificate from them. Follow these instructions to generate a CSR for your domain.

1. SSH into your webserver with your login name and password.
2. Create a directory to store your certificate key, certificate CSR, and certificate.

mkdir certs ; cd certs

3. Type the following command to generate your RSA private key, please adjust the filename 'domainname.key' accordingly.

openssl genrsa -out domainname.key 2048

4. Type the following command to create a CSR with the RSA private key, adjusting the filenames for your domain name (output will be PEM format):

   openssl req -new -key domainname.key -out domainname.csr

5. When creating a CSR you must follow these conventions. Enter the information to be displayed in the certificate. The following characters can not be accepted: < > ~ ! @ # $ % ^ * / \ ( ) ?.,&

   DN Field	Explanation	Example
   Common Name	The fully qualified domain name for your web server. This must be an exact match.	If you intend to secure the URL https://www.geotrust.com, then your CSR's common name must be www.geotrust.com.
   Organization	The exact legal name of your organization. Do not abbreviate your organization name.	GeoTrust
   Organization Unit	Section of the organization	Marketing
   City or Locality	The city where your organization is legally located.	Wellesley Hills
   State or Province	The state or province where your organization is legally located. Can not be abbreviated.	Massachusetts
   Country	The two-letter ISO abbreviation for your country.	US

6. Do not enter extra attributes at the prompt.

Warning: Please leave the challenge password blank (press <enter>)

Note: If you would like to verify the contents of the CSR, use the following command:

openssl req -noout -text -in domainname.csr

7. Submit your CSR to your SSL signing company. You can either download the 'domainname.csr' file via FTP and view it locally, or you can use 'cat' to view it at the prompt.

cat domainname.csr

Note: You can also self-sign a certificate, for testing purposes. (viewers will see a security warning)


openssl x509 -req -days 365 -in host.csr -signkey host.key -out host.crt

8. Create a backup of your private key!

   Make a copy of the private key file (domainname.key) generated in step 3 and store it in a safe place! If you lose this file, you must purchase a new certificate.