ecc.rb

# derived from http://h2np.net/tips/wiki/index.php?RubyOpenSSLDigitalSignatureSample

require 'openssl'
require 'base64'
include OpenSSL

group_name = 'secp521r1'
message = '10000 fartbux sent to bryce from a can of beans'
key = PKey::EC.new(group_name)
key = key.generate_key

puts 'private'
puts key.to_text
puts 'public'
puts key.public_key.to_bn

digest = Digest::SHA512.digest(message)
puts 'digest'
puts Base64.encode64 digest

signature = key.dsa_sign_asn1 digest
puts 'signature'
puts Base64.encode64 signature

group = PKey::EC::Group.new(group_name)
point = PKey::EC::Point.new(group, key.public_key.to_bn)
# verifier = PKey::EC.new(group)
verifier = key
verifier.private_key = nil
verifier.public_key = point
puts 'verify key'
puts verifier.to_text

puts 'verifying:'
puts verifier.dsa_verify_asn1(digest, signature).inspect