SimpleSignature.configure do |c|
    c.init_keystore(keys)  
    c.expiry_time = 900                   # default is 900
    c.key_param_name = 'sigkey'           # default is 'sigkey'
    c.signature_param_name = 'signature'  # default is 'signature'
    c.timestamp_param_name = 'timestamp'  # default is 'timestamp'
    c.logger = Logger.new($stdout)        # default is nil (no logger). Can be a lambda.
  end  

  {
    'key1': { secret: 'xxxx' },
    'key2': { secret: 'yyy' }
  }

file_path = File.join("config", "keystore.yml")
file_path = File.join("config", "keystore-sample.yml") unless File.exist?(file_path)

keys = YAML.load_file(file_path)

SimpleSignature.configure do |c|
   c.init_keystore(keys)
end

generator = SimpleSignature::Generator.new(key) do |g|
  g.include_all({ method: method, path: path, params: params, body: body })
end

generator = SimpleSignature::Generator.new(key)

generator.include_all({ method: method, path: path, params: params, body: body })

generator.reset!  # to clean the previous data and prepare the generator for a new signature

generator.signature
generator.timestamp
generator.auth_hash     # a Hash containing the signature key, signature and timestamp
generator.auth_params   # a query string representation of the auth_hash, ready for inclusing in a URL query params

# This class will validate a request method, path, params and body
# A specific logger (or nil) can be provided, overwriting the one specified in SimpleSignature.configure
# A specific expiry time (in seconds) can be provided, overwriting the default (900) or the one specified in SimpleSignature.configure
validator = SimpleSignature::RequestValidator.new(request, {:logger => Rails.logger, :expiry_time => 1800})

validator.success? # true or false

# In case of error (success = false)
validator.error.code
validator.error.message

secret = 'secret'
timestamp = 1396536298  # NOW, as an integer number of seconds since the Epoch
payload = 'signable tokens' + timestamp.to_s
digest = OpenSSL::Digest::SHA1.new

hmac = OpenSSL::HMAC.hexdigest(digest, secret, payload)