# Encoding: utf-8
# Cloud Foundry Java Buildpack
# Copyright 2013-2016 the original author or authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require 'fileutils'
require 'java_buildpack/component/versioned_dependency_component'
require 'java_buildpack/framework'
require 'java_buildpack/util/qualify_path'

module JavaBuildpack
  module Framework

    # Encapsulates the functionality for enabling zero-touch Safenet Luna HSM Java Security Provider support.
    class LunaSecurityProvider < JavaBuildpack::Component::VersionedDependencyComponent
      include JavaBuildpack::Util

      # (see JavaBuildpack::Component::BaseComponent#compile)
      def compile
        download_tar
        setup_ext_dir

        @droplet.copy_resources

        credentials = @application.services.find_service(FILTER)['credentials']
        write_client credentials['client']
        write_servers credentials['servers']
        write_configuration credentials['servers'], credentials['groups']
      end

      # (see JavaBuildpack::Component::BaseComponent#release)
      def release
        @droplet.environment_variables.add_environment_variable 'ChrystokiConfigurationPath', @droplet.sandbox

        @droplet.java_opts
          .add_system_property('java.security.properties', @droplet.sandbox + 'java.security')
          .add_system_property('java.ext.dirs', ext_dirs)
      end

      protected

      # (see JavaBuildpack::Component::VersionedDependencyComponent#supports?)
      def supports?
        @application.services.one_service? FILTER, 'client', 'servers', 'groups'
      end

      private

      FILTER = /luna/.freeze

      private_constant :FILTER

      def chrystoki
        @droplet.sandbox + 'Chrystoki.conf'
      end

      def client_certificate
        @droplet.sandbox + 'client-certificate.pem'
      end

      def client_private_key
        @droplet.sandbox + 'client-private-key.pem'
      end

      def ext_dir
        @droplet.sandbox + 'ext'
      end

      def luna_provider_jar
        @droplet.sandbox + 'jsp/LunaProvider.jar'
      end

      def luna_api_so
        @droplet.sandbox + 'jsp/64/libLunaAPI.so'
      end

      def lib_cryptoki
        @droplet.sandbox + 'libs/64/libCryptoki2.so'
      end

      def lib_cklog
        @droplet.sandbox + 'libs/64/libcklog2.so'
      end

      def setup_ext_dir
        FileUtils.mkdir ext_dir
        [luna_provider_jar, luna_api_so].each do |file|
          FileUtils.ln_s file.relative_path_from(ext_dir), ext_dir, force: true
        end
      end

      def ext_dirs
        "#{qualify_path(@droplet.java_home.root + 'lib/ext', @droplet.root)}:" \
        "#{qualify_path(ext_dir, @droplet.root)}"
      end

      def logging?
        @configuration['logging_enabled']
      end

      def padded_index(index)
        index.to_s.rjust(2, '0')
      end

      def relative(path)
        path.relative_path_from(@droplet.root)
      end

      def server_certificates
        @droplet.sandbox + 'server-certificates.pem'
      end

      def write_client(client)
        FileUtils.mkdir_p client_certificate.parent
        client_certificate.open(File::CREAT | File::WRONLY) do |f|
          f.write "#{client['certificate']}\n"
        end

        FileUtils.mkdir_p client_private_key.parent
        client_private_key.open(File::CREAT | File::WRONLY) do |f|
          f.write "#{client['private-key']}\n"
        end
      end

      def write_configuration(servers, groups)
        chrystoki.open(File::APPEND | File::WRONLY) do |f|
          write_prologue f
          servers.each_with_index { |server, index| write_server f, index, server }
          f.write <<EOS
}

VirtualToken = {
EOS
          groups.each_with_index { |group, index| write_group f, index, group }
          write_epilogue f
        end
      end

      def write_epilogue(f)
        f.write <<EOS
}

HAConfiguration = {
  AutoReconnectInterval = 60;
  HAOnly = 1;
  ReconnAtt = 20;
}
EOS
      end

      def write_group(f, index, group)
        padded_index = padded_index index

        f.write "  VirtualToken#{padded_index}Label   = #{group['label']};\n"
        f.write "  VirtualToken#{padded_index}SN      = 1#{group['members'][0]};\n"
        f.write "  VirtualToken#{padded_index}Members = #{group['members'].join(',')};\n"
        f.write "\n"
      end

      def write_lib(f)
        f.write <<EOS

Chrystoki2 = {
EOS

        if logging?
          write_logging(f)
        else
          f.write <<EOS
  LibUNIX64 = #{relative(lib_cryptoki)};
}
EOS
        end
      end

      def write_logging(f)
        f.write <<EOS
  LibUNIX64 = #{relative(lib_cklog)};
}

CkLog2 = {
  Enabled      = 1;
  LibUNIX64    = #{relative(lib_cryptoki)};
  LoggingMask  = ALL_FUNC;
  LogToStreams = 1;
  NewFormat    = 1;
}
EOS
      end

      def write_prologue(f)
        write_lib(f)

        f.write <<EOS

LunaSA Client = {
  NetClient = 1;

  ClientCertFile    = #{relative(client_certificate)};
  ClientPrivKeyFile = #{relative(client_private_key)};
  HtlDir            = #{relative(@droplet.sandbox + 'htl')};
  ServerCAFile      = #{relative(server_certificates)};

EOS
      end

      def write_server(f, index, server)
        padded_index = padded_index index

        f.write "  ServerName#{padded_index} = #{server['name']};\n"
        f.write "  ServerPort#{padded_index} = 1792;\n"
        f.write "  ServerHtl#{padded_index}  = 0;\n"
        f.write "\n"
      end

      def write_servers(servers)
        FileUtils.mkdir_p server_certificates.parent
        server_certificates.open(File::CREAT | File::WRONLY) do |f|
          servers.each { |server| f.write "#{server['certificate']}\n" }
        end
      end

    end
  end
end
