HOW TO- Convert .pem file to a .der file with OpenSSL

Recently I have the need to convert an SSL cert I retrieved from a Citrix NetScaler device from the native format, .pem, into a format that was more digestible to Windows Server. In order to do this you’ll need the OpenSSL library for windows. You can find it at http://slproweb.com/products/Win32OpenSSL.html

Once you have it installed, make sure you run the following command to setup the config file in your command prompt. Remember to replace the [openssl install directory] with the location you installed OpenSSL “set OPENSSL_CONF=c:[openssl install directory]binopenssl.cfg” Once you have all that set you can run the following command to convert the .pem file to a .der file “openssl x509 –in [your pem file].pem –out [full path and filename of the file you want to create].der –outform DER”

This will convert your .pem file to a .der file which you can now import into a Windows Server.

Hope this helps.