openssl x509 -sha1 -fingerprint -noout -in cert.pem

data = File.read("cert.pem")
data["-----BEGIN CERTIFICATE-----n"]=""
data["-----END CERTIFICATE-----n"]=""
OpenSSL::Digest::SHA1.new(Base64.encode64(data))

file_data = File.read("cert.pem")
cert = OpenSSL::X509::Certificate.new(file_data)
puts OpenSSL::Digest::SHA1.new(cert.to_der).to_s

cert = R509::Cert.load_from_file("cert.pem")
puts cert.fingerprint('sha1')

OpenSSL::Digest::SHA1.new(Base64.decode64(data))

openssl x509 -in cert.pem -out cert.der -outform der

data2 = File.read("cert.der")
 print OpenSSL::Digest::SHA1.new(data2)