To generate a RSA key
openssl genrsa -out privkey.pem 2048
To generate a DSA key
openssl dsaparam -out dsaparam.pem 2048
Creating a certificate request
openssl req -new -key privkey.pem -out cert.csr
Creating a self-signed test certificate
openssl req -new -x509 -key privkey.pem -out cacert.pem -days 1095