How to Create a Self-Signed Certificate
In public key infrastructure, self-signed certificates are ones that are signed and validated by the creator of the certificate instead of a publicly acknowledged certifying authority. Certifying authorities assure the Internet surfer that the certificate being used on a website is actually created by the owner of the website, where a self-signed certificate could be faked by a computer hacker. Self-signed certificates, however, are used for testing one's website before paying for a certificate from a CA. A self-signed certificate can be created using publicly available software.
Download and install OpenSSL (see Additional Resources).
Open the DOS shell on your computer: Open the "Start" menu and type
"cd openssl" in the search text field. Hit "Enter" to change to the OpenSSL directory.
Generate an SSL server key by typing the following command at the DOS prompt followed by the "Enter" key: "openssl genrsa -des3 -out server.key 4096"
Input the data that OpenSSL requests, such as company name, country and mailing address. Then, request a server signing request by typing the following command at the DOS prompt followed by "Enter": "openssl req -new -key server.key -out server.csr "
Sign the digital certificate by typing the following command at the DOS prompt followed by "Enter": "openssl x509 -req -days 365 -in server.csr -signkey server.key -out server.crt "Source: ehow.com