diff --git a/doc/keycert.rb b/doc/keycert.rb
new file mode 100644
index 0000000..df947cc
--- /dev/null
+++ b/doc/keycert.rb
@@ -0,0 +1,20 @@
+require 'openssl'
+
+key = OpenSSL::PKey::RSA.new 4096
+
+open 'private_key.pem', 'w' do |io| io.write key.to_pem end
+open 'public_key.pem', 'w' do |io| io.write key.public_key.to_pem end
+
+name = OpenSSL::X509::Name.parse 'CN=lex-deeit/DC=weird-web-workers/DC=org'
+
+cert = OpenSSL::X509::Certificate.new
+cert.version = 2
+cert.serial = 0
+cert.not_before = Time.now
+cert.not_after = Time.now + 3600
+
+cert.public_key = key.public_key
+cert.subject = name
+cert.sign key, OpenSSL::Digest::SHA256.new
+
+open 'public-key.crt', 'w' do |io| io.write cert.to_pem end