0d0a

0D 0A (\r\n)

Openssl generate public private key pair rsa

Private only:
openssl genrsa -des3 -out private.pem

Public from private:
openssl rsa -in private.pem -pubout -out public.pem

Self-signed certificate from private:
openssl req -new -x509 -nodes -sha1 -days 365 -key private.pem > self.cer

Works on linux, mac os x, cygwin and everything running openssl.

StringBuffer vs StringBuilder

Use StringBuilder when possible. Read the javadocs for more detail.