Ruby Quellcode

=begin
Audio Encryption
Positives:
- Protects your own custom audio files
- Gives a point to having a BGM test inside your game
Negatives:
- Audio files take slightly longer to load
- mp3 files do not encrypt
- Once encrypted, audio files will not play in rmxp gui, only in the game
 
Simply play the audio in rmxp to encrypt. Backup audio files before using. It's a low security method and this script is more for people who create their own audio files.
code:
#############################################################################
# Script by: BEHEMOTH #                                                     #
#######################                                                     #
#Version: 1.0                                                               #
#Date Created: October 26th 2006 8:42 PM (Eastern Standard Time)            #
#Description: An encryption script for audio files.                         #
#Thanks goes to thephantom from http://www.phanxgames.com/ for pointing out #
#the whole encryption key idea which I was too blind to see.                #
#############################################################################
 
#############################################################################
#                    ***IMPORTANT RESTRICTIONS***                           #
#1) If the audio file is an .mp3 file, it will NOT encrypt the file and it  #
#will play it normally. If you wish to have your mp3 file encrypted please  #
#save it as another compatible audio file, such as .ogg, .mid               #
#or .wav(compressed of course) or .wma                                      #
#                                                                           #
#2) Your audio files must NOT be: read only, or hidden, or protected in     #
#anyway or it will not encrypt the file and it will play it normally.       #
#                                                                           #
#3) Audio files should not have the same filename with a different          #
#   extension.                                                              #
#   BAD:  "battle01.mid" "battle01.ogg"                                     #
#   GOOD: "battle01.mid" "battle02.ogg"                                     #
#                                                                           #
#4) Files from an RMXP RTP will not be encrypted and will play normally.    #
#############################################################################
 
#############################################################################
#                            ***NOTES***                                    #
#Positives:                                                                 #
# - Protects your own custom audio files                                    #
# - Gives a point to having a BGM test inside your game                     #
# - Ummmm.......it's cool                                                   #
#                                                                           #
#Negatives:                                                                 #
# - Audio files take slightly longer to load                                #
# - mp3 files do not encrypt                                                #
# - Once encrypted, audio files will not play in rmxp gui, only in the game #
# - The audio file is slightly bigger in file size then the orginal file    #
#                                                                           #
#If you have problems, suggestions, comments about this script then you can #
#currently find me here: http://www.phanxgames.com/forum/                   #
#                                                                           #
#How to Use:                                                                #
#To encrypt your audio files play the file in your game at least once.      #
#The script will handle the rest. MAKE SURE TO BACK UP YOUR ORIGINAL        #
#AUDIO FILES BEFORE ENCRYPTING IT, because it automatically overwrites      #
#the original file with the encrypted file. To make this script encrypt     #
#only certain audio files such as BGM, BGS, ME, SE then change the values   #
#of the variables below named:                                              #
#ENCRYPT_BGM, ENCRYPT_BGS, ENCRYPT_ME, ENCRYPT_SE                           #
#     (located below class Game_System)                                     #
#changing the value to true means those files will be encrypted and false   #
#means those files will not be encrypted. Changing these values when an     #
#audio file is encrypted may cause undesired results. So choose what you    #
#want first then start encrypting your audio files. Deleting the Encryption #
#key file (default = "audio.edat") after encrypting your audio will also    #
#result in undesired results....so don't delete or move that file once      #
#you've been encrypting or else you'll have to start encrypting all your    #
#audio again. This script is more for people who create their own audio     #
#files.                                                                     #
#############################################################################
=end
 
class Game_System
  ENCRYPT_EXT        = ".eaudio"     #Encrypted file extenstion
  ENCRYPT_FILE       = "audio.edat"  #File containing encrypted data
  ENCRYPT_KEY_LENGTH = 16            #Number of characters for encryption key
 
  #Change encryption for certain audio files.......HERE!!!!!
  ENCRYPT_BGM        = true          #Encrypt bgm?
  ENCRYPT_BGS        = false         #Encrypt bgs?
  ENCRYPT_ME         = false         #Encrypt me? Yes, please! lol
  ENCRYPT_SE         = false         #Encrypt se?
 
  #--------------------------------------------------------------------------
  # * Play Background Music
  #     bgm : background music to be played
  #--------------------------------------------------------------------------
  def bgm_play(bgm)
    @playing_bgm = bgm
    if bgm != nil and bgm.name != ""
      filename = "Audio/BGM/" + bgm.name
      if ENCRYPT_BGM
        decrypt_file(filename)
        Audio.bgm_play(filename, bgm.volume, bgm.pitch)
        encrypt_file(filename)
      else
        Audio.bgm_play(filename, bgm.volume, bgm.pitch)
      end
    else
      Audio.bgm_stop
    end
    Graphics.frame_reset
  end
  #--------------------------------------------------------------------------
  # * Play Background Sound
  #     bgs : background sound to be played
  #--------------------------------------------------------------------------
  def bgs_play(bgs)
    @playing_bgs = bgs
    if bgs != nil and bgs.name != ""
      filename = "Audio/BGS/" + bgs.name
      if ENCRYPT_BGS
        decrypt_file(filename)
        Audio.bgs_play(filename, bgs.volume, bgs.pitch)
        encrypt_file(filename)
      else
        Audio.bgs_play(filename, bgs.volume, bgs.pitch)
      end
    else
      Audio.bgs_stop
    end
    Graphics.frame_reset
  end
  #--------------------------------------------------------------------------
  # * Play Music Effect
  #     me : music effect to be played
  #--------------------------------------------------------------------------
  def me_play(me)
    if me != nil and me.name != ""
      filename = "Audio/ME/" + me.name
      if ENCRYPT_ME
        decrypt_file(filename)
        Audio.me_play(filename, me.volume, me.pitch)
        encrypt_file(filename)
      else
        Audio.me_play(filename, me.volume, me.pitch)
      end
    else
      Audio.me_stop
    end
    Graphics.frame_reset
  end
  #--------------------------------------------------------------------------
  # * Play Sound Effect
  #     se : sound effect to be played
  #--------------------------------------------------------------------------
  def se_play(se)
    if se != nil and se.name != ""
      filename = "Audio/SE/" + se.name
      if ENCRYPT_SE
        decrypt_file(filename)
        Audio.se_play(filename, se.volume, se.pitch)
        encrypt_file(filename)
      else
        Audio.se_play(filename, se.volume, se.pitch)
      end
    end
  end
  #--------------------------------------------------------------------------
  # Finds the extension of an audio filename with no extension
  #--------------------------------------------------------------------------
  def get_file_ext(filename)
    if FileTest.exist?(filename + ".wav")
      return ".wav"
    elsif FileTest.exist?(filename + ".mp3")
      return ".mp3"
    elsif FileTest.exist?(filename + ".ogg")
      return ".ogg"
    elsif FileTest.exist?(filename + ".mid")
      return ".mid"
    elsif FileTest.exist?(filename + ".wma")
      return ".wma"
    else
      return ENCRYPT_EXT
    end
  end
  #--------------------------------------------------------------------------
  # Encrypts an audio file and saves it with the encrypted extension and
  # deletes the non encrypted file if it was not already encrypted.
  #--------------------------------------------------------------------------
  def encrypt_file(filename)
    ext = get_file_ext(filename)
    filen = filename + ext
    # If file doesn't not exist in project/audio folder then exit.
    # File either doesn't exist or is part of the RTP.
    if (not FileTest.exist?(filen))
      return
    end
    # Load File
    afile = File.open(filen, "rb")
    t = afile.readlines
    afile.close
    #If filename was not previously encrypted
    if ext != ENCRYPT_EXT
      begin
        # Test if file is writeable
        afile = File.open(filen, "wb")
        afile.close
        # Delete File
        File.delete(filen)
      rescue
        #File could not be encrypted
        return
      end
    end
    get_encryption
    # Save File
    filen = filename + ENCRYPT_EXT
    afile = File.open(filen, "wb")
    for i in 0...t.size
      s = @encrypt_data + t[i]
      t[i] = s
    end
    Marshal.dump(t, afile)
    afile.close
  end
  #--------------------------------------------------------------------------
  # Decrypts a file if it is encrypted.
  #--------------------------------------------------------------------------
  def decrypt_file(filename)
    filename += ENCRYPT_EXT
    #If file is not encrypted
    if (not FileTest.exist?(filename))
      return
    end
    get_encryption
    # Load File
    afile = File.open(filename, "rb")    
    t = Marshal.load(afile)
    for i in 0...t.size
      s = t[i]
      t[i] = s[ENCRYPT_KEY_LENGTH, t[i].size]
    end    
    afile.close
    # Save File
    afile = File.open(filename, "wb")
    for i in 0...t.size
      afile.write(t[i])
    end
    afile.close
  end
  #--------------------------------------------------------------------------
  # * Retrieve's encryption data from file. If file doesn't exist then it
  #   creates an encryption data file.
  #--------------------------------------------------------------------------
  def get_encryption
    # No encryption data(method) found
    if @encrypt_data == nil
      # Encryption data file exists?
      if FileTest.exist?(ENCRYPT_FILE)
        # Load Data File
        afile = File.open(ENCRYPT_FILE, "rb")
        @encrypt_data = Marshal.load(afile)
        afile.close
      else
        # Create encryption data file
        afile = File.open(ENCRYPT_FILE, "wb")
        Marshal.dump(create_key, afile)
        afile.close
      end
    end
  end
  #--------------------------------------------------------------------------
  # * Returns ENCRYPT_KEY_LENGTH character randomized string used to encrypt
  #   the audio file
  #--------------------------------------------------------------------------
  def create_key
    key = ""
    for i in 0...ENCRYPT_KEY_LENGTH
      key_num = rand(36)
      key_char = key_num.to_s(36)
      upper_case = rand(2) == 1
      if key_num > 9 && upper_case
        key_char.upcase!
      end
      key += key_char
    end
    return key
  end
  #--------------------------------------------------------------------------
end