Create a certificate using OpenSSL
How to: create a self-signed certificate using OpenSSL
If you want to create a self-signed certificate with validity periods other than 1 year, or with additional information about yourself, you can use a tool such as Open SSL to create it, rather than the standard MakeKeys utility that comes with the SDK.
The following commands, which are based on the suggestions given here, show how to create a self-signed key/certificate pair with a lifetime of 10 years:
openssl genrsa 1024 >selfsigned.key openssl req -new -x509 -nodes -sha1 -days 3650 -key selfsigned.key >selfsigned.cer
After entering the second command, you are prompted for various bits of information about yourself that is embedded into the certificate. This process only needs to be performed once, and the generated certificate can then be kept for future use with CreateSIS or SignSIS.