Verifying signature in ruby

can-we-verify.rb

require 'base64'
require 'openssl'

DEFAULT_PUBLIC_KEY_FILE = 'keys/demo-server/pubkey901'

RESP = '2!200!!20130404T013030Z!1365039030-16998-4!http%3A%2F%2Flocalhost%3A3001%2F!test0001!pwd!!36000!'
RAW_SIG = 'EJhXHSEuaj2T3U-f-8OMCIb2DSkFvx7jRUFY5EgGlLiyKlWcR7s1DI..FJLKGc6Otb9rKFK-haF7NvyzMMmOkbx1iKZSgUXW5B420-dW.7TPOB187xcHzQezPSw7rHxrq2byp-pRkT7G9TDWDrqAMblasSsN3s8Nanifp1gOcxA_'

sig = RAW_SIG.tr('-._','+/=')
key = IO.read( DEFAULT_PUBLIC_KEY_FILE ).to_s

puts "Verifying signature"
puts sig

puts "Using key:"
puts key

publickey = OpenSSL::PKey::RSA.new( key )
ok = publickey.verify( OpenSSL::Digest::SHA1.new, Base64.decode64(sig), RESP)

puts "Signature verified: #{ ok }"