# private key
openssl genrsa -out privkey.pem 2048

# public key
openssl rsa -in privkey.pem -pubout -out pubkey.pem
ok , for the dummy like myself , when it comes to someone asked me for a public key to set the login of the development , i do not know what to do ,but thanks google search for the answer above which i hope when some one need to manage Local Malaysia openERP server which require our public key, the instruction can be there for a reference. 
For Windows user , you can go to download the windows version of the openSSL .