#   Copyright (c) 2010, Diaspora Inc.  This file is
#   licensed under the Affero General Public License version 3 or later.  See
#   the COPYRIGHT file.

module Encryptable
  def signable_string
    raise NotImplementedException("Override this in your encryptable class")
  end

  def signature_valid?
    verify_signature(creator_signature, person)
  end

  def verify_signature(signature, person)
    if person.nil?
      Rails.logger.info("event=verify_signature status=abort reason=no_person guid=#{self.guid} model_id=#{self.id}")
      return false
    elsif person.public_key.nil?
      Rails.logger.info("event=verify_signature status=abort reason=no_key guid=#{self.guid} model_id=#{self.id}")
      return false
    elsif signature.nil?
      Rails.logger.info("event=verify_signature status=abort reason=no_signature guid=#{self.guid} model_id=#{self.id}")
      return false
    end
    log_string = "event=verify_signature status=complete model_id=#{id}"
    validity = person.public_key.verify "SHA", Base64.decode64(signature), signable_string
    log_string += " validity=#{validity}"
    Rails.logger.info(log_string)
    validity
  end

  def sign_with_key(key)
    sig = Base64.encode64(key.sign "SHA", signable_string)
    Rails.logger.info("event=sign_with_key status=complete model_id=#{id}")
    sig
  end

end