How to create a .pem file for SSL Certificate Installations

How to create a .pem file for SSL Certificate Installations

Privacy Enhanced Mail (PEM) files are concatenated certificate containers frequently used in certificate installations when multiple certificates that form a complete chain are being imported as a single file. They are a defined standard in RFCs 1421 through 1424. They can be thought of as a layered container of chained certificates. A .pem file is a container format that may just include the public certificate or the entire certificate chain (private key, public key, root certificates):

• Private Key
• Server Certificate (crt, puplic key)
• (optional) Intermediate CA and/or bundles if signed by a 3rd party

How to create a self-signed PEM file

openssl req -newkey rsa:2048 -new -nodes -x509 -days 3650 -keyout key.pem -out cert.pem

How to create a PEM file from existing certificate files that form a chain

• (optional) Remove the password from the Private Key by following the steps listed below:

  openssl rsa -in server.key -out nopassword.key

  Note: Enter the pass phrase of the Private Key.
  
  
• Combine the private key, public certificate and any 3rd party intermediate certificate files:
  

  cat nopassword.key > server.pem
  cat server.crt >> server.pem

  Note: Repeat this step as needed for third-party certificate chain files, bundles, etc:
  

  cat intermediate.crt >> server.pem

How to create a PEM file with the help of an automated script:

• Download NetIQ Cool Tool OpenSSL-Toolkit.
• Select Create Certificates | PEM with key and entire trust chain
  
• Provide the full path to the directory containing the certificate files.
• Provide the filenames of the following:
• private key
• public key (server crt)
• (conditional) password for private key
• (conditional) any intermediate certificate chain file(s)

For additional information, please see TID 7015502 - Common Mistakes in SSL Certificate Management & Implementation.

The following details the structure of a typical .pem file (including the entire certificate chain):

-----BEGIN RSA PRIVATE KEY----- 
(Private Key: domain_name.key contents) 
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE----- 
(Primary SSL certificate: domain_name.crt contents) 
-----END CERTIFICATE----- 
-----BEGIN CERTIFICATE----- 
(Intermediate certificate: certChainCA.crt contents) 
-----END CERTIFICATE----