gistfile1.rb

require 'openssl'

key = OpenSSL::PKey::DSA.generate 1024
puts key.to_pem

cert = OpenSSL::X509::Certificate.new
cert.version = 2
cert.serial = 1
cert.subject = OpenSSL::X509::Name.new [['CN', 'Test CA']]
cert.issuer = cert.subject
cert.not_before = Time.now
cert.not_after = Time.now + 365 * 24 * 60 * 60
cert.public_key = key.public_key
cert.sign key, OpenSSL::Digest::SHA1.new
puts cert.to_pem