To create a Certificate Signing Request (CSR)

1. Launch Keychain Access, located in ==>Applications---->Utilities.
   2.
   
   Choose Keychain Access ---> Certificate Assistant ---> Request a Certificate From a Certificate Authority.
   
   
   In the Certificate Information window:
   
   In the User Email Address field, enter your email address.(Here only enable two option)
   2.
   
   In the Common Name field, enter your name.

3. In the Request is group, select the Saved to disk option.
   4.
   
   Select Let me specify key pair information.
   5.
   
   Click Continue.
   6.
   
   Choose your desktop as the location for the CSR file.
   7.
   
   In the Key Pair Information pane, choose 2048 as the key size and RSA as the algorithm.
   
   The Certificate Assistant saves a CSR file to your desktop