   Ͽ(Security HOWTO)

  Kevin Fenzi, kevin@scrye.com : ڹμ, dolman@correl1.snu.ac.kr
  v0.9.2, 31 January 1998

     ý  ڰ ´ڶ߸ Ǵ Ȼ 鿡
   ̴.     Ϲ   ý
  ħڷκ  ϰ ϴ    ʵ ٷ
  , ȿ  ڷ α׷ ϴ  ԵǾ ִ.
  :    Ͽ Ÿ ̴.  ̳ Ǽ ,
  ߰  ׵鿡    ȯѴ.   
  ִ (despam)       "linux" "secu
  rity", "HOWTO" ؾ ŷο    ִ.
  ______________________________________________________________________

   

  1.      Ұ

  1.1.       

  1.2.    Feedback

  1.3.     

  1.4.    ۱ 

  2.      

  3.       

  3.1.    ǻ ġ

  3.2.    BIOS 

  3.3.    Boot loader 

  3.4.    xlock vlock

  3.5.    Detecting Physical Security compromises.

  4.       ڵ鿡  

  4.1.    ο  

  4.2.    Ʈ 

  4.3.    Ʈ 

  4.4.    н  & ȣȭ

  4.4.1.  PAM - Pluggable Authentication Modules

  4.4.2.   н

  4.4.3.  Crack John the Ripper

  4.5.    Tripwire ̿  ˻

  4.6.    CFS - Cryptographic File System  TCFS - transparent
  cryptographic File System.

  4.7.    X11, SVGA ÷ .

  4.7.1.  X11

  4.7.2.  SVGA

  4.7.3.  GGI (Generic Graphics Interface project)

  4.8.    identd

  5.      Ʈ 

  5.1.    Ŷ (Packet Sniffers)

  5.2.    ý 񽺿 tcp_wrapper

  5.3.    SATAN ISS,   Ʈ ˻ α׷

  5.4.    pgp public key ȣۼ/ص

  5.5.    ssh stelnet

  5.6.    sendmail, qmail MTA.

  5.7.     źθ ̿ .

  5.8.    NFS (Network File System) .

  5.9.    NIS (Network Information service) ( YP).

  5.10.   ȭ

  6.      ħ ް    Ŀ ؾ ͵.

  6.1.       .

  6.2.    ̹ Ͼ  Ѽ.

  6.2.1.   

  6.2.2.   

  6.2.3.  , , !

  6.2.4.  ħ 

  7.       ڷ

  7.1.    FTP Ʈ

  7.2.     Ʈ Ŀ FAQ Ŀ鿡  FAQ̴.

  7.3.    ϸ Ʈ

  7.4.    å - μ Ÿ.

  8.      

  9.       
  ______________________________________________________________________

  1.  Ұ

     ȿ  ġ   ߿  
  ٷ.  Ϲ  ͳ   ڷ鿡 
  ̾߱Ѵ.

  ٸ  Ͽ  ȹ ٷ ִ.  ̷ 
    Ͽ.

    ֽ ħԻǵ ٷ  ƴϴ.   ο
  ǵ    ִ.    ٸ п ׷ ǿ
   ֽ  ħ     Ϲ  ãƺ
   ִ  ְ   ̴.

  1.1.     

    ο  ֱ comp.os.linux.answers ׷,
  ftp://sunsite.unc.edu/pub/Linux/docs/HOWTO   ͸
  FTPƮ鿡 ÷ ̴.

  ƿ﷯  Ϲ   Ʒ   WWW Ȩ
  ã  ִ.

  http://sunsite.unc.edu/mdw/linux.html

   http://scrye.com/~kevin/lsh/   ֽ  
   ÷ ̴.

  1.2.  Feedback

      , ߰ װ  Ʒ ּҷ 
  ٶ.

  kevin@scrye.com

  :   ϵ ɷ   ͸  ִ.  
  ʹ 𸣴 Լ  ,  key ־ ٽ
  ޶  ٿ ݼ۽ .     ŷο 
   , Ϸ翡 20-30 뾿 ƿ    ϵ 
  ̷    .  ݼ Ͽ ִ key  
  ٽ ָ     ִ.   "linux"
  "security", "HOWTO" ϸ ̷ ŷο    ִ.

  http://scrye.com/~kevin/

  1.3.   

  ڴ   뿡  ü å .     
  ϴ    å̴.    Ÿ  
  Ȯ     ɼ ִ.

   Ƿʿ  (tm) Ű  ý 
  Ƿ,   ٸ  ִ.

  ڰ ƴ ,  Ͽ    ǰų 򰡵
   ִ α׷鸸 Ͽ.  κ α׷ GNU 
   ҽ Ͽ  Ӱ    ̴.

  1.4.  ۱ 

    ۱ (c)1998 Kevin Fenzi , Ʒ Ͽ
    ִ.

  o   ۱ ȳ ԵǴ , ̰ų   ü
       Ͽ  ü Ȥ Ϻθ ϰ  
     ִ.         ڿ
     ˷ֱ ٶ.

  o   ̳ Ļ ۾,  Ͽ  ϴ
     ۾  ۱ ȳ  Ѵ.     
     Ͽ ̿ ۾ ϰ    ΰ 
     ޾Ƽ  ȴٴ ̴.   Ȳ  Ģ  ܵ
       Ƿ, Ʒ ּҸ ؼ  Ͽ ڿ
     ϱ ٶ.

  o  ǹ ִٸ  Ͽ  Greg Hankins Ʒ ּҷ
     ϱ ٶ.

  gregh@sunsite.unc.edu ȭȣ ּҰ ʿϸ finger ϵ
  ϶.

  2.  

      ý  ϰ ϱ   
    ̴ Ʈ鿡   ̴.

  켱 ؾ   "Ϻϰ"  ǻ ý   
    ٴ ̴.     ִ  ٸ  ýۿ
  ħϴ    ư  ̴.     
  ڵ ׻ ũĿ ħԿ ϰ  ʿ  .
  ̳ ȸ    ڵ ξ   
  ￩ Ѵ.

   ϳ ο ξ    ý  ȭ  
    ŷο  ȴٴ ̴.   ý Ǽ
        ؾ Ѵ.   
  ýۿ ȭ ϰ  ڴ ݵ ڱ  ݹ(call
  back)     ִ.  ̷ ϸ ý Ȯ  ־
   ,    ڴ   Ƿ ϴ.
    ý ͳݿ Ű   ,   
  ƴٴϱⰡ  .    ߰ Ը ̻ Ʈ
  Ѵٸ,    ʿϰ    ϴ
  ϴ " å" ϴ  .

       ٷ     ִ.
   ȿ  ù   ǻͿ ٸ  Ժη 
   ϵ ϴ   ٷ.   °   ڵ
  ý Ժη  ϵ ϴ  Ѵ.   ° 
  Ʈ  ٷ  Ʈκ κ 
   ý  ϰ ϴ   Ѵ.  
     ý ħ ߰ų, ֱٿ ׷ ħ ־ٴ
   ߰   ؾ ϴ  ̴.  ׸  ٸ
    ڷ ũ ϰ,     ̴.

    鼭 Ȯ ؾ      .

  o   ý ¸ ľϰ  .  /var/log/messages 
     ϵ Ȯϰ,   ý 캸 ־ Ѵ.

  o   ý ֽ ·  .  ̸ ؼ
     Ʈ ֽ  ġߴ,    
     ׷̵带 ߴ Ȯؾ߸ Ѵ.  ̷ ϴ ͸ε
     ý ϰ µ ū   ̴.

  3.   

   ο ξ  ù ܰ ǻ  ̴.
   ǻ ü     ִ°?  ׷ ʿ䰡 ִ ΰ?
     ý ϴ    ִ°?  ׷ ؾ
   ΰ?

   ýۿ     ʿ Ȳ 꿡
   ſ ٸ.

    ٸ ̵̳  ģô ǻ͸ ǵ帮
  ϵ ϱ ؾ߰, Ư  ȿ Ű  ʿ 
  ̴.  ǿ ٸ ξ  ؾ  ڵ
  ǻͿ ۾   ־ Ѵ.      
   ̴.  繫ǿ  ĳ  ٸ    ǻͿ
   ϵ ؾ  ְ ׷   ִ.  
  ȸ 쿡 ǻ ܼ      θ
  ġ    ִ.

   Ŵ ڹ質 罽, ĳ ״ ,  ġ 
     и  ,    ̴. :)

  3.1.  ǻ ġ

    ǻ ̽鿡 ""  ִ.  ġ 밳
   ü    ̿ؼ װų Ǯ Ǿ ִ.  
  ġ ׸ ٸ   pc ġų, ̽  
  ϵ ϰų İ ϵ   ִ.  δ ٸ
   ǻ͸ ڱ ÷ǳ ٸ ϵ ýų  
    ִ.

  ̷ ̽ ġ   ̽   ٸ
   Ѵ.   pc ̽  ؼ ̽ ıؾ
  ϵ  ִ.  ٸ pc ο Ű峪 콺  
   Ǿִ.        ̽
   ϵ ϶.  ̷ ġ 밳 ſ   
   δ    ִ.

   ̽ (ַ Ű )  (dongle) ־ ڰ
  罽    ִ.  ̷ Ǹ ħڰ ü ο 
   罽 ų ̽ ıؾ Ѵ.  ڹ踦  ۿ
  ä ͸ε ǻ͸ ġ Դ Ǹ ֹ  
  ִ.

  3.2.  BIOS 

  ̿(BIOS) x86 CPU   ϵ ϴ  
   Ʈ.  γ    Ʈ α׷ 
   Ű  ϱ  ̿ Ѵ.  
  ư ٸ ϵ  ̿  Ʈ ִ.
  (ư   ǻ OpenFirmware, sun boot prom ) ħڰ
  ǻ͸ ٽ ýŰ  ý ϴ   ؼ
  ̿  ̿  ִ.

  x86      pc ̿ Ʈ н带
    ֵ Ǿ ִ.  ̷    
   (̿ ½ų  ְ, ̽   ִٸ ƿ 
    ִ),  ֹ    ̴.( ϴµ 
   ð ɸ ϰ    ̴)

   x86 ̿ ̹ۿ پϰ Ǹ   ɵ
  Ѵ.    ִ ̿ Ŵ Ȯϰų   
  ̿  ڼ  ٶ.    ÷ ̺긦
  ̿  Ұϰ ϰų Ư ̿ ɿ ϱ
  ؼ н带 Էϵ ϴ    ִ.

  ſ ư , SPARC  ÿ н带 
    ִ.  ̷ ϸ ħ ӵ    ̴.

  : Ȥ  ӽ ϸ鼭 Ʈ н带 ߴٸ, 
  ǻʹ  ־߸  ϴٴ  ؾ Ѵ.  ߿
   ƴص ٽ ƿͼ н带 Էؾ Ѵ. ;(

  3.3.  Boot loader 

     Ʈ δ  н带   ִ.  θ
  ٸ "restricted" "password"  캸 ϶.  "password"
    н带 ϴ ̰, "restricted" 'lilo:'
  Ʈ  Ư ɼ(single ) ԷµǴ 쿡 
  ʵ ϴ ̴.

  ϴ н ϰ   н  ؾ Ѵٴ
   ϶. :) ƿ﷯  н  ħϰڴٰ  
   ħڿԴ ð ִ ҹۿ Ѵٴ  ؾ
  Ѵ.

  Ȥ ٸ Ʈ δ    ƴ  ִٸ ڿ
  ˷ֱ ٶ(grub, silo, milo, linload ).

  :  ӽ ϸ鼭 Ʈ н带  ξٸ, 
  ־   ϴ.  ѹ߿  Ǿص ͼ
  н带 Էؾ Ѵٴ  ϶.

  3.4.  xlock vlock

   ǻ   ٸ, ٸ   ۾ ų
   ϵ ܼ ""  ִ  .  ̷  
    α׷ xlock vlock̴.

  xlock X  ȭ Ѵ.   α׷ X ϴ 
    ִ.  Ϲ  ϴ ܸ ƹ
  xterm xlock ų  , ϴ Ǹ ȭ
  Ǹ鼭  н尡 ԷµǾ ȭ Է  · 
   ְ ȴ.   ڼ û ش   ãƺ ϶.

  vlock   ܸ Ϻγ θ   ֵ ϴ
   α׷̴.     ܸ   ۾ 
  ϳ    ִµ, ̷ Ǹ ٸ  ͼ ܸ⸦
    ,  ۾ ̴  ܸ  ϱ
      ȴ.  vlock   , 
  ϴ    ִ.

   ܸ⸦ ν   ۾ ϴ   
  ְ ǻ͸ ٽ  Űų ۾ ߴܽѹ  
   .

  3.5.  Detecting Physical Security compromises.

   ؾ  ֿ켱   ǻͰ  õǾ° ̴.
   ߰ϰ  ü̱ , ǻͰ
  õǾ߸ ϴ  ü ׷̵峪 ϵ  
  ؼ '' ýų ̴.     ʾҴµ
  ǻͰ õǾٸ,     ִ.  ǻͿ ħϴ
    ϴ  ǻ͸ ýŰų   ϴ
  ͵  ִ.

  ǻ ̽  ֺ    ִ Ȯؾ Ѵ.
   쿡 ħڵ log  ̿ܿ ڽ  ,
  ǻͿ  ٹ  캸  ̻  Ȯϴ  .
   log Ͽ Ȯؾ    .

  o  ªų ҿ .

  o  ̻ ð ǥø  .

  o  ߸ 㰡̳   .

  o  ̳  ۿ  .

  o   .

  o  su ϰ ̻ κ  .

  log   ִ  ϴ   ٸ.
  ǥ   /var/log/  ޽ mail.log,  
  ϵ Ȯ   ̴.

  4.   ڵ鿡  

   ָؾ    (local user) ݿ 
  ̴.  ڰ  __ ڵ̶ ߴٴµ ָϱ
  ٶ.

    ٱ  ̾߸ ýۿ ħϰ ϴ
     õϴ   ϳ.   ڵ鿡 
  ϸ, ħڵ   ׵ ý ϴ 
   ̿ؼ ׵  ִ   ٱ (root)
  ٱ "׷̵"   ִ.   ڵ鿡  
  öϸ ħڵ پѾ   ϳ ֹ  Ǵ ̴.

   ¥ ƴ϶ ص (¼ ٷ ̷ 쿡)  ڵ
   ý    ִ.   𸣰ų  
  𸣴 鿡  ִ  ſ   ̴.

   ý ̰ 㰡 ٲٱ   ϰ ִ  Ȯ
  ϰ ִ Ȯϵ ϶.   ۵ϵ ϴ  
  ٴ   㰡 ٲٴ   ȵȴ.  
  㰡 ٲٱ   ׷ 㰡  ϴ ϵ ϶.

  4.1.  ο  

      ۾  ּ Ѹ ؾ
  Ѵ.      Ƶ鿡  شٸ,  μ ׸
  α׷   Ѹ ־ ϸ,  ̰   ֵ
  ؼ  ȴ.

  ٸ   ٱ Ϸ  , ο  Ʒ 
   Ģ ִ.

  o  ڵ鿡Դ ׵ ʿ ϴ ּ Ѹ ־ Ѵ.

  o  ڵ / α ϴ Ȥ α ؾ ϴ ˾ƾ
     Ѵ.

  o  ڵ  ̻  ʿ䰡 ٸ ׵  ϰ
     Ȯ϶.

  ħԿ Ǵ    밳   ̻  ʰ
  ִ ͵̴.  ƹ ϰ  ʱ  ̷  ְ
    ȴ.

  4.2.  Ʈ 

   ýۿ  ϴ  ٸ  ڴ  
  ,  ٷ ̴! :)  Ʈ  ſ ª Ư ۾
  ؼ ϸ, κ 쿡  ڽŵ  ڷμ
  ؾ Ѵٴ  ؾ Ѵ.  ׻ Ʈ ۾ ϴ  ſ
  ſ ſ  ̴.  Ʈ ؾ߸ ϴ Ư ۾ ؼ
  su sudo  ϶.

  Ʈ ۾ϴٰ ڽ ǻ͸ ׹   ϱ 
     ִ.

  o       ı    
     ϶.  Ư ϵī带   쿡 ϶.   
     "rm foo*.bak" ϱ   "ls foo*.bak" ؼ  
     ϴ ϵ鸸  Ǵ Ȯؾ Ѵ.  ı 
      ڸ  ͵ δ  ̴.

  o    "touch /-i"    ȴٰ Ѵ.  
      "rm -rf /"    , ſ  
     ϵ    ϴ ̴.

  o   Ư ϳ ۾ ϱ ؼ Ʈ ǵ ϶.   
     ϴ  ˾Ƴ ʹٸ, Ʈμ Ǿ߸ ϴ ۾
      Ȯ    з ư ϶.

  o  Ʈμ ۾    ϰ ϰ ൿ϶.
      ϴ ൿ  ͵鿡    ִ.   
     Ŀ  ε!

  (ٶǴ   )   ǻͿ μ
     ̰ Ȯ ʿ䰡 ִٸ,   
     ִ.  Sudo ڰ ڽ н带 Ἥ  
  ѵ  Ʈμ   ֵ ش.   sudo ̿ؼ
   ý  ڰ ٸ Ʈμ Ư  Ͼ
  õ̳  ϰų Ʈϴ  ϵ   ִ.
  sudo   ϱ    ߴ   ֵ,
   sudo  õ    ۼѴ.  ̷  
   Ʈ ٱ       ֵ
  sudo  ϴ  .

  4.3.  Ʈ 

  Ʈ 񸶴 ȣ  ǰ   å
  Ե ̸̴.  ׷ ̴  α׷̳  
  ε , ٸ  װ ٿ ޾Ƽ Ʈμ 
  Ѵٴ ̵.  ׷ Ǹ   Ų  Ǹ
   ʴ  ׵ ý ջų  ִ.  ڵ 
  ޾ƿ      (Ƹ ſ ) Ѵٰ ϰ ִ
  ,   ׵  ջŲ.

   ǻͿ ġ α׷   Ǹ ￩ Ѵ.
   md5 checksum pgp ǥð  rpm ϵ ϹǷ ġϰ
  ִ α׷ ¥ Ȯ  ִ.  ҽ  ְų ſ
    ƴ ,   ϵ Ʈμ Ѽ  ȴ!
  ҽ Ͽ  ˻縦 ޵ ϴ ħڴ  .

    ,  α׷ ҽ ùٸ ó
  Դ Ȯϵ ϶.  α׷ Ʈμ ų ̶,
  ̳    ҽ Ⱦ Ȯϵ ؾ Ѵ.

  4.4.  н  & ȣȭ

  ȣ ó ̰ ִ  ߿    ϳ.
  ϰ    н带   ſԳ 
  ڵ鿡Գ ߿ ̴.     κ 
    ִ н    ϴ 'passwd' α׷
  ϰ ִ.   passwd α׷ ̷ Ư  ִ
  ֽ Ȯϵ ϶.

  ȣȭ         , Ұ
  ʿϴ.  ȣȭ ſ ϸ,   ô뿡 ʼ̱
  ϴ.  󿡴 ڷḦ ȣȭϴ   ,  
  ԰  ִ.   ˰ ־    ̴ 
  Ʒ  ͵ ִ.

  н ȣ ȣȭ(unix password encryption): κ н ü
  ( ܰ ƴϴ)  н带 ȣȭϱ  DES(ڷ
  ȣȭ ǥ, Data Encryption Standard) Ѵ.  ̷ ȣȭ
  н () /etc/passwd (Ȥ  ϰԴ) /etc/shadow 
  ȴ.   α Ϸ õϸ,  Է  ٽ
  ȣȭǾ passwd   װ 񱳵ȴ.   ġϸ 
  н иϹǷ   㰡ȴ.  DES Ϲ 
  ȣȭ ̴.  DES  ǻͰ    ô뿡 
  ϴٰ ˷ ִ.  н尡  ұĢ 
  ƴ϶, crack̳ John the ripper (Ʒ ÿ)   ݿ
   н带  ϴ 찡   ִ.  PAM 
  н带 Ű  (MD5  ) ٸ ȣȭ   
  ֵ ش. (Ʒ ÿ)

  4.4.1.  PAM - Pluggable Authentication Modules

     ο  "PAM"̶ ο  ϰ
  ִ.  PAM ý  ߿   䱸 ٲ  ֵ
  ش.   ̳ʸ ϵ ٽ  ʿ䰡 .  PAM 
      ѾǷ  ڼ  ʿϴٸ PAM
  Ʈ 캸 ٶ.
  http://www.kernel.org/pub/linux/libs/pam/index.html

  PAM   ִ       Ʒ .

  o  DES ƴ ȣȭ  н忡 .  (н带  ȣ
     ص õ  ߰ϰ )

  o   ڵ鿡   ڿ  ν, ׵
      ź     Ѵ.(μ , ޸
      )

  o   ߿  н带 ϰ Ѵ.(Ʒ ÿ)

  o  Ư ڰ Ư ð Ư ҿ α  ֵ
     Ѵ.

  4.4.2.   н

   н  ڵκ ȣȭ н 
  ȣϱ    ̴.  밳 ȣȭ н  
   ִ /etc/passwd Ͽ ȴ.   н带 س
  α׷  Ͽ ؼ н尡  ˾Ƴ  
  ִ.   н н忡   Ư  ִ
  ڵ鸸   ִ /etc/shadow Ͽ Ѵ.  
  н带 Ϸ, н   ʿ䰡 ִ 
  ƿƼ  н带 ϵ ٽ  Ǿ
  Ȯؾ Ѵ.  ռ Ұ PAM  α׷ ٽ  ʿ
      ӽŴν  н带   ֵ
  ش.

  4.4.3.  Crack John the Ripper

        н带  ϴ  
  passwd  ʴ´ٸ, н ũŷ α׷ Ѽ 
  ڵ  н带  ִ Ȯϰ   ִ.

  н ũŷ α׷  ̵  ۵Ѵ.  ̷
  α׷  ִ  ܾ   Ѵ.  
  ܾ ȣȭϿ ý ȣȭ н ϴ ̴.
  ࿡  ´ ܾ ãԵǸ, ȣ ˾Ƴ ̴.

  󿡴  н ũ α׷ ִ.   ߿  Ǹ 
    ٷ "Crack" "John the Ripper".
  http://www.false.com/security/john/index.html  α׷ cpu
  û ϰ,   н ũ α׷ Ẹ
   н带  ڵ ˾Ƴν, ڰ ̷
  α׷ Ἥ ýۿ ħ  ִ Ȯؾ Ѵ.  ڴ
   passwd (н /etc/passwd)   ؼ  ٸ
   ̿Ͽ ϰ, ̷   ϴ ͺ ξ
  ϴٴ  ؾ Ѵ.

  4.5.  Tripwire ̿  ˻

  Tripwire   ˻ α׷ Ű ͵  ڿ
   (׸ Ʈ ) ý  Žس ſ 
  ̴.  Tripwire ý ߿  ϵ  ϵ ο
   ۾ ϰ    ̷ ͺ̽
  Ѵ.     ȭ ؼ ȣ ް ȴ.

  Tripwire ÷ǿ ġϰ    ٿδ  .
  ̷ ϸ ħڴ tripwire ü ϰų ͺ̽ ٲ 
   ȴ.  ϴ tripwire ġϰ , Ϸ翡   Űų
  ؼ  ٲ  ִ Ȯ   .

  Tripwire   ħڸ س  ִٴ   ֽ
    ִ.   밳 ý  ϵ ٲǷ 
  ũĿ ̰   ڽ   ؼ  Ѵ.

  4.6.  CFS - Cryptographic File System  TCFS - transparent crypto
  graphic File System.

  CSF  ý ü ȣȭϰ ڵ ȣȭ  
  ȣȭ  ýۿ   ֵ ִ ̴.  ̰
   ǻͿ   NFS  Ѵ.  rpm 
  http://www.replay.com/redhat/   ְ,  ۵Ŀ 
   ftp://ftp.research.att.com/dist/mab/   ִ.

  TCSF ȣȭ  ý  ڿ    ǵ 
  ϼ  CSF  ̴.  http://edu-gw.dia.unisa.it/tcfs/
        ִ.

  4.7.  X11, SVGA ÷ .

  4.7.1.  X11

  ׷ ÷  ߿ϴ.  ڰ  𸣰 
  Էϴ н带 äų,   ũ 󿡼 а ִ
    аų,      ̿ϱ
  ϴ ϵ  ؼ.  Ʈ ؼ ִ ǻ  X
  α׷ ϴ ͵  (sniffer) Ű 
  ý  ȣۿ    ֱ   ϴ.

  X     ִ.     ȣƮ 
  ̴.   ÷̿   ִ ȣƮ ϱ ؼ
  xhost   ִ.   xhost    
  ƴϴ.    ǻͿ ߴٸ ׵ "xhost +׵
  ǻ" Էؼ    ִ.  ƿ﷯   
  ǻͷκ  ߴٸ,  ǻ  ̰ 
  ÷̸   ִ.

  α  xdm(x display manager) ٸ,    
  MIT-MAGIC-COOKIE-1   ִ.  128 Ʈ cookie ϳ
    .Xauthority Ͽ ȴ.   ǻͿ 
  ÷̿ ϴ   ʿ䰡 ִٸ,  ǻͷκ
    ϱ  xauth ɰ  .Xauthority Ͽ
  ִ    ִ.

   X  ؼ ssh( ִ ssh  )   ִ.
  ssh ȣȭ  ڷ Ʈ  귯 ٴ   ϸ,
   ڿԴ ƹ ٸ   ʴ´ٴ   ִ.

  X ȿ     ʿϸ Xsecurity man  
  ٶ.    ֿܼ αϱ ؼ xdm , X
  α׷  Ű   Ʈ  ؼ ssh
   ̴.

  4.7.2.  SVGA

  SVGAlib α׷   ǻͿ ִ  
  ϵ   ֵ ϱ  Ʈ  (suid) Ǿ
  ִ.    α׷ , 밳 ܼ ϱ ؼ ٽ
  ýѾ Ѵ.   Ű մ  SVGA α׷ ó
  и , ּ    Ȯ϶.     SVGA
  α׷ ƿ Ű ʴ ̴.

  4.7.3.  GGI (Generic Graphics Interface project)

   GGI ȹ   ̽   
   ذϰ ϴ õ̴.  GGI  ڵ  κ
   Ŀ  Ű  ̸,  ýۿ  
   ̴.  ̰ GGI   ܼ  ̹ ˷ 
  · ȸų  ִٴ  Ѵ.  GGI  ó ؼ
   ֿܼ ǰ ִ α α׷ Ʈ 񸶰 
  Ȯ  ִ.  http://synergy.caltech.edu/~ggi/

  4.8.  identd

  identd ַ inetd ܺο Ǵ  α׷,  ڰ
   tcp 񽺸 Ű ϰ,  䱸ϸ  
  Ѵ.

    identd 뼺 ϰ, ̰  ʵ
  ϰų ܺηκ  û źϵ Ƶд.  identd 
  Ʈ  ֱ ؼ ִ  ƴϴ.    identd
   ڷᰡ    .  identd û ƹ  
  .

  ׷ٸ   identd Ѿ ұ?  identd __
  ֱ ̰,  ãƳ   ٸ ڷ̱ ̴.
   identd  ʾҴٸ  tcp 񽺸  ִ
    ̸̳ uid identd  Ʈ ְ ִ
   ˰ ȴ.   ϳ  Ʈ ڰ ſ ãƿͼ
   ǻ ڰ ڱ Ʈ ħϷ ߴٰ Ѵٸ,
     ڿ ؼ ൿ   ִ.   identd
  Ű  ʾҴٸ,  ϵ 캸    ־
  ãƳ Ѵ.  ̷  Ϲ ξ  ð ɸ ȴ.

  κ ǿ ִ identd   ϴ ͺ 
  پ  ϴ.  Ư ڵ鿡 ؼ identd ۵
  ʵ   ְ(̷ ڵ .noident    ִ), 
  identd û ϵ   (ڴ ̷ ϱ⸦ Ѵ)
   ̸  uid NO-USER ȯϵ   ִ.

  5.  Ʈ 

     ð Ʈ  ·   Ʈ
    ߿ ִ.  Ʈ  մ   ̳
    մ   밳 ξ   ξ  Ͼ.

  Ʈ      ,    
   Եǰ ִ.

  5.1.  Ŷ (Packet Sniffers)

  ϴ  ȣƮ ħ ħڰ Ʈ    ý۵鿡
       ϰ ϴ   ϳ ̹
  ħ ȣƮ Ŷ ۸ ϴ ̴.   "" ̴
  Ʈ  Ŷ 帧  "Password", "Login", "su"  Ϳ
  ͸ ̰,     صд.  ̷ ؼ
  ڴ ħϷ õ ʾҴ ý  н带
   ȴ.   ؽƮ н ̷ ݿ ſ ϴ.

  : ȣƮ A ̹ ħ ߴ.  ڴ ۸ ġѴ.
  ۴ ȣƮ C ȣƮ B    ,
  ڰ B α    н带 ´.   
  ڰ   ذϱ  'su' ϸ, ۴ ȣƮ
  B Ʈ н带  ȴ.  ߿ ڰ ڱ κ ٸ
  Ʈ ִ ȣƮ Z ڳ ϸ, ڴ ȣƮ Z α
  н  ȴ.

  ó ڰ Ŷ ۸    ýۿ ħ
  ʿ .  ڵ ž̳ PC ǹ   ͼ
  Ʈ ϸ Ǵ ̴.

  ssh ٸ ȣȭ н  ϸ ̷   
  ִ.  pop   ATOP  ͵     ִ.
  (   ؽƮ н带 ϴ   ׷,
   pop α ۿ  ϴ.)

  5.2.  ý 񽺿 tcp_wrapper

   Ʈ   ý  ,   
    񽺸 Ͽ ϴ° ̴.   ʿ䰡 
  񽺴 Ƽ Ÿ ϳ , ڰ  ã  
  ϳ ٿ Ѵ.

   ýۿ 񽺸 Ұϰ ϴ   ִ.  
  /etc/inetd.conf    inetd  񽺸 ϰ
  ִ ˾ƺ  ִ.  ʿ  񽺴  ּ ó ؼ
  ƹ (#   տ), inetd SIGHUP ȣ  ϶.
  ƿ﷯ شϴ 񽺸 /etc/services Ͽ ּ ó ϰų
    ִ.

    Ű     ȴٸ,  Ű
     ִ.    rpm -e  
  Ű ü   ִ.  ȿ dpkg  ۾  
   ̴.

   /etc/rc.d/rcN.d Ȯؾ Ѵ.  ⼭ N  ý 
  ̴.   ͸ ȿ   Ǵ   Ȥ
  ʿ   ִ .  ʿ  ũƮ ׳ ,
        ʴ´.  BSD  rc
  ϵ  ִٸ ʿ  α׷ /etc/rc* Ȯؾ
  Ѵ.

  κ     tcp 񽺵
  "ִ(wrapping)" tcp_wrapper ִ.  inetd 䱸 
  ¥   tcp_wrapper (tcpd) ϳ .  tcpd 񽺸 û
  ȣƮ Ȯϰ, û 񽺿 شϴ  Űų 
  ȣƮκ  źѴ.   tcpd ̿ؼ  tcp
  񽺷    ִ.  /etc/hosts.allow  ,
   ǻ 񽺿  ʿ䰡 ִ ȣƮ鸸 ߰ϵ
  Ѵ.      ڶ, ڴ  񽺿 
   źϵ Ѵ.  tcpd 񽺿 Ϸٰ 
  õ ϹǷ,  ް ִٴ  ˷  ִ.  tcp
   ο 񽺸 ߰ ϰ Ǹ, ݵ tcp wrapper
    񽺸 ߰Ͽ Ѵ.

  5.3.  SATAN ISS,   Ʈ ˻ α׷

  󿡴 Ʈ 񽺸  ǻ͵ Ʈ  ˻縦
  ϴ  Ʈ Ű ִ.  SATAN ISS  
    ˷ α׷̴.   Ʈ ǥ ǻ (Ȥ
   Ʈ   ǥ ǻ͵)   Ʈ Ϸ
  õϸ,  񽺰 ǰ ִ ãƳ Ѵ.   
   ǥ ǻͰ  ݿ  ã  ִ.

  SATAN(Security Administrators Tool for Analyzing Networks) 
  ̽  Ʈ ˻ α׷̴. ǻ  볪 ϳ
  Ʈ  ˻  , ,    ִ.  SATAN
  ؼ  ǻͳ Ʈ غ ߰ߵ  ġ 
  .  SATAN Ʈ  FTP,  Ʈ ϵ ؾ
  Ѵ.  ͳݿ SATAN  Ʈ 񸶰 ־ ̴.
  http://www.trouble.org/~zen/satan/satan.html

  ISS (Internet Security Scanner) Ʈ  ˻ϴ  ٸ
  α׷̴.  SATAN  ,  Ը Ʈ ˻ϱ⿡
     ִ.   SATAN    ϴ 
  ִ.

  Ʈ ˻ ϱ.

  SATAN̳ ISS  Ʈ  ǻ͸ Žϰ ִٴ 
  溸ֵ     ִ.   tcp_wrapper 
  Ȱϰ  ϵ  캸⸸ ص, ׷ Ž
  ˾  ִ.  tcp_wrapper     δ
  SATAN   ý Ͽ ڱ .

  5.4.  pgp public key ȣۼ/ص

   pgp (pretty good privacy)  Ѵ. 2.62 5.0  
  ۵Ѵٰ ˷ ִ.  pgp  Ǹ Թ 
  ʿϴٸ pgp FAQ  ٶ.
  http://www.pgp.com/service/export/faq/55faq.cgi

  5.5.  ssh stelnet

  ssh (secure shell) stelnet  ý αΰ 
  ȣȭ ִ α׷̴.

  ssh ȣƮ spoofing  Ƴ (ssh  Ǿ
  ȣƮκ Ư Ű ƿ⸦ Ѵ),  ǻͿ 
   ȣȭ  ƴ϶  X11 forwarding Ѵ.  ssh
  packet sniffer  ġϱ⿡ ſ .  (packet sniffer
  ȣȭ Ŷ  ٹ  ̴)  ssh  ڿԴ
  ̹Ƿ  Ʈ ġؼ ϵ Ѵ.
  http://www.cs.hut.fi/ssh/

  stelnet ڳ  ȣȭִ ڳ  ü̴.

  5.6.  sendmail, qmail MTA.

     ִ  ߿ 񽺵  ϳ 
  ̴.  ϰԵ   ݿ    
  ϳε,    װ ؾ ϴ ۾ ڿ ʿ
  ϴ   ̴.

  sendmail  ִٸ, ֽ  ϴ  ſ ߿ϴ.
  sendmail ſ ſ   Ȼ  ݴ Դ.  ׻
   ֱ  ϵ ϶. http://www.sendmail.org

   sendmail  ׷̵ϱ⿡ ƴٸ, qmail ٲ㺸 ͵
  غ  ϴ.  qmail ó  ο ΰ Ǿ.  
  α׷  ̰ ϴ. http://www.qmail.org

  5.7.   źθ ̿ .

   źθ ̿  ý ڿ Ϻθ ſ ٻڰ ,
   û  ϰ ų,   ý 
  źϰ  ̴.

  ̷  ٳ⿡  ũ ؿԴ.   ֱ ݹ
    ˷ ͵ Ʒ Ұߴ.  ο ݹ ׻
  Ÿ Ƿ  Ұ ͵    ʿ Ұϴٴ
   ؾ Ѵ.   ο     Ʈ
  е ϶.

  SYN (flooding).  SYN ̶ Ʈ   ź ̴.
    TCP    ִ "" ̿Ѵ.
  (2.0.30 ) ο  Ŀε SYN  ݿ  
   ǻͳ 񽺿  ϴ   
  CONFIG_SYN_COOKIES CONFIG_RST_COOKIES    ɼǵ
   ִ.  SYN    ̱ ؼ  ɼǵ
  ؼ Ŀ ٽ  ϵ ϶.

  Ƽ "FOOF" .   ǰ Ƽ μ Ϸ 
  ڵ带   ǻͰ  ٴ  ֱٿ ߰ߵǾ.
  ̰  üΰ  (ǰ Ƽ , Ƽ2
  ) Ƽ μ ϴ  ǻͿ  ģ.
  2.0.32 ̻  Ŀο  ׷  ǻͰ ٿǴ 
    ۾  ԵǾ ִ.  Ƽ ϰ ִٸ, 
  ׷̵带 ؾ Ѵ.

  Ping . Ping  ϰ   ź  ̴.
  ڴ ICMP Ŷ ϳ ""  ǻͿ .  ڰ
     ǻ   ļ 뿪  ǻͿ Ѵٸ,
   ǻʹ Ʈ ƹ ͵     ̴.  
  ݹ   ϳ "ĵŸ"  ǻ IP 
  ư ؼ ICMP Ŷ ٸ ȣƮ .  ̷ ϸ
  ãƳⰡ  .  Ping   ް ִٸ, 𿡼
  Ŷ  (Ȥ  ó ̴) ˾Ƴ ؼ tcpdump 
    ϶.  ׸  Ʈ ڿ  
  ϵ ϶.  Ping   ؿ ϴ   .

  5.8.  NFS (Network File System) .

  NFS ſ θ ̴   ̴.  NFS ̿ϸ nfsd
  Ű  ü  ý mountd ϴ ٸ ǻ͵
    ִ.   Ʈ ڵ鿡 Ȩ͸ ϱ
   NFS ϰ , ̷ ν ڵ α 
   ǻ̰ ڵ ׵  Ȩ ϵ  ȴ.

  Ͻý     ִ ""    ִ.
    ǻ Ʈ (uid=0) nobody ڷ Ѽ,
   Ͻýۿ  ٱ   źϵ nsfd
  ؾ Ѵ.  ׷  ڴ  (Ȥ ּ  uid)
  Ͽ  ٱ ֱ ,   ڱ 
  α̳ su  ϸ, ڱ ϵ鿡 ؼ  ٱ
    ִ.  ̷ ϴ   Ͻý Ʈ  
  ڿԴ  ֹۿ  Ѵ.

  NFS  Ѵٸ,  ؾ߸ ϴ ǻ͵θ Ű
  ϶.  Ʈ ͸ θ ؼ  ȵǸ, ʿ
  ͸鸸 ؾ Ѵ.

  NFS   ڼ  ʿϸ NFS Ͽ  ϶.  NFS
  HOWTO

  5.9.  NIS (Network Information service) ( YP).

  Ʈ  (Network Information service,  YP)  
  ǻ͵鿡  ִ   ̴.  NIS   ǥ
   鼭 װ͵ NIS  ϵ ȯѴ.    ϵ
  Ʈ  ν NIS Ŭ̾Ʈ ǻ͵ αΰ
  н, Ȩ ͸ п  (  /etc/passwd Ͽ
  ִ  )   ְ ȴ.  NIS ̿ϸ ڵ
  н带   ٲν  NIS  ִ  ǻ͵鿡
     ִ.

  NIS   ϴ.  ϵ ϰ ߴ  .
  NIS ϰ  ֵ ȵǾ.  (Ʈ   ְ)
   NIS  ̸   ִ   passwd 
  纻   ְ,   н带   crack john
  the ripper   ְ ȴ.  NIS ӿ °  Ӽ 
   ִ.   NIS  ٸ, ̷   ˰ ־ Ѵ.

  5.10.  ȭ

  ȭ(firewall)   Ʈ    ִ 
  ϴ   ̴.    ȭ ȣƮ ͳݰ
   lan Ű, lan ͳ   ȭ ؼ
  ϵ ϴ ̴.  ̷ ϸ ȭ ͳݰ  lan
  ̸     ִ.

  ȭ ϴ    ִ.   ǻʹ 
  ϸ鼭 Ǹ ȭ   ִ.  ȭ ڵ  
  2.0 ̻ Ŀο ٷ Ե  ִ.     ipfwadm
  ,  ߿ Ǵ Ʈ   ٲ  ִ.

  ȭ Ʈ ϰ ϴ ſ ߿ϰ  ̴.
   ȭ ϱ   Ʈ ִ ǻ͵  ʿ
  ٰ ؼ   ȴ.  ̷ ϴ  ġ
  Ǽ.  ȭ        
  Ʈ  ſ Ǹ ȭ Ͽ о ϶.
  http://sunsite.unc.edu/mdw/HOWTO/Firewall-HOWTO.html

  6.  ħ ް    Ŀ ؾ ͵.

   ħ       ϰ Ѵ.  ù °
     ϴ ̴.   ൿ ڰ   ִ
  ͺ  ū ظ ĥ  ִ.

  6.1.     .

      ˾  Ǵ   ִ.  
   ϴ°  ߿    ִ.

    ̶,  ˾ ̻   ̳
  繫, ǿ ħߴٴ  ̴.    åڿ
  ˷ Ѵ.  ǿ  ̽  ߰ų ǻ͸
  Ϸ ߴٴ  ˾ ̴.   Ѱ 
  ,  ׵鿡 ϵ 䱸ϰų   åڿ
    ִ.

   ڰ  Ѽϰ ϴ   ,  
  ؾ    ڰ   Ȯϴ ̴.   ڰ
  𿡼 αϷ ϰ ִ Ȯ  ϶.   
  ÿ α  ΰ?  ׷ ?  ǻ͸
      غ ϶.    ȭ ɰų
     Ȥ 繫Ƿ   ̾߱⸦   ִ.   
  ڰ ڱ  Ѵٸ,    ؼ
  ϵ 䱸  ְ ׷  ϶   ִ.  װ
  ϰ,  ϴ ǿ ؼ 𸥴ٸ   縦 ؾ Ѵ.
   ǵ ˾ƺ  ̳    
  Ȯϵ ϶.

  Ʈ  ħ ߴٸ, ó   (   ִٸ)
  Ʈ   ̴.  ħڰ  ߴٸ  
  ̾ƹ ϰ, ̴  ߴٸ ̴  ̾ƶ.
  ̷ ϸ ħڰ  ū ظ     ְ, ħڴ
  Ƹ ڽ 복ٰ ϱ⺸ٴ Ʈ   ̶
   ̴.

   Ʈ    ٸ (  Ʈ̰ų,
  ǻͿ    ٸ), å ħ
  Ʈκ      tcp_wrapper ipfwadm 
  α׷ ϴ ̴.

  ħ Ʈ     ź  ٸ,
  ڵ  Ͽ Ѵ.  ϳ  ϴ  
   ƴ϶  ϶.   .rhosts ϰ FTP  ,
  ȣƮ  ޹(backdoor) ο ξ Ѵ.

   ġ (Ʈ ,  Ʈκ   õ ź,
  ׸/Ȥ ׵  )    ϰ , 
    μ ̰ ׵ α  Ѿ Ѵ.

  ڴ ٽ  õ ̹Ƿ,     
  Ʈ ڼ ؾ Ѵ.  ڴ Ƹ ٸ   ̰,
  ٸ Ʈ ּҸ   ִ.

  6.2.  ̹ Ͼ  Ѽ.

   ̹ Ͼ  ڴʰ ˾  ְ  ϰ
  (ٶδ) ڸ  ýۿ Ƴ  ִ.  
   ؾ ұ?

  6.2.1.   

  ڰ  ýۿ       
  ִٸ,    ؾ Ѵ.    ڰ α 
   FTP ׵     ߰  ִ.   
  FTP 񽺸 ϰ  ̳ ˷    ִ
  ãƺ Ѵ.

  (log) ϵ Ȯϰ,  ã  Ʈ   ĥ
   ִ Ӱ  ʰ ִ  캸 ϶.

  ڸ   ʾҴٸ, ״ 밳 ٽ ƿ´.  
  ǻͷ ٷ ƿ ,  lan    ̴.
  ڰ Ŷ ۸ ۵Ű ־ٸ, ״   ٸ
  ǻͷ   ִ.

  6.2.2.   

  ù °   ظ ϴ ̴.   ѼյǾ°?
  Tripwire   ˻ α׷ ϰ ִٸ, tripwire
  Ѽ ˾ƺ  ִ.  ̷ α׷ ٸ,  ߿
  ڷ  캸ƾ Ѵ.

   ý  ġϱ  Ƿ,  ϵ
   ΰ ũ    ٽ ġ 
  κ  ϰ  ϵ ϴ    
  ִ.  ̷ ϸ  ý   ȴ.

  6.2.3.  , , !

    صδ    ־  ̴.
   ý  ,  κ  ϴ ڷḦ
    ִ.   ڿԵ ġ ִ ڷ İ ڱ
  纻    ıϰ, ּ  ڷḦ 
    ʴ´.

      ϱ ,   
  Ȯ ƾ Ѵ.  ħڰ    ĳҴٸ, ͸
  ϵ鸸 ܶ    ֱ ̴.

   鿡 ؼ   ִ.    ҿ
  ξ ȮϿ ϰ,  ű   ִ ˰ ־ Ѵ.
  (ڰ    ִٸ,  𸣴 ̿  
  ڷῡ   ְ Ǵ ̴.)

  6.2.4.  ħ 

  ħڸ Ƴ, ý ߴٰ ؼ    
  ƴϴ.  밳 ħڵ  , ׷   ؾ
  Ѵ.

   ڰ  ý ߴ Ʈ ڿ  
  ˷־ Ѵ.  ó "whois" internic ͺ̽ ̿ؼ
  ãƺ  ִ.     װ ¥  ð ÷ؼ 
  ڿ email   .  ħڿ ؼ  Ư 
  ߰ߴٸ װ͵ Բ ˷ֵ ϶.  email  ڿ (ϰ
  ʹٸ) ȭ ϵ ϶.   ڰ ٽ  ڸ
  ãƳ´ٸ,  ڰ ٽ ڰ  Ʈ ڿ
  ϰ  ׷.

  پ Ŀ 밳  ߰ ý۵ Ѵ.   ý۵ 
   (Ȥ )  ħ ߴٴ    ִ.
  ũĿ  ý۱ Ѿư   ̴.  
  ̾߱ϰ Ǵ ڵ鿡 ϰ ϴ  ׵κ 
  µ .

    (cert ̿ )   鿡 ˷־
  Ѵ.

  7.   ڷ

  н  Ϲݿ  Ȥ Ư  ȿ  Ǹ
  Ʈ   ִ.  ϳ ̻   ϸ Ʈ
  ؼ ֽ  ׵ 󰡴  ſ ߿ϴ.  ̷
  Ʈ 밳 ſ з 鼭 ϴ.

  7.1.  FTP Ʈ

  CERT ǻ   (Computer Emergency Response Team) ڴ.
  ̵  ֱ  ǰ ׵鿡  溸  Ѵ.
  cert.org

  Replay   α׷ ϰ ִ.  Replay ̱ ȿ
   ʱ  ̱  ȣ ѿ  ʿ䰡 .
  replay.com

  Matt Blaze CFS ̸ Ź  ̴.  Matt Blaze's
  stuff

  Sorosis  PAM Ʈ ̴.  ⿡ PAM  
    ִ.  Linux PAM ftp site

  tue.nl ״忡 ִ Ǹ   ftp Ʈ̴.
  ftp.win.tue.nl

  7.2.  Ŀ FAQ Ŀ鿡  FAQ̴. The Hacker FAQ  Ʈ

  COAST ڷǿ ſ  н  α׷  ִ.
  COAST

  Rootshell.com ũĿ   ħ  ˾ƺ⿡ 
  Ʈ̴.  rootshell.com exploits

  BUGTRAQ     Ȳ ǥѴ. BUGTRAQ archives

  ǻ   , CERT н ýۿ    
  Ѵ.  CERT home

  Dan Farmer SATAN  ٸ   ̸, 
  ȨƮ    ƴ϶ ȿ  ̷ο  ۵鵵
  ִ.  Dan Farmers  trouble.org

    WWW  ý ȿ   ڷ̴.  Linux
  Security WWW

  Reptile  Ʈ  ȿ     ִ.
  Reptiles Linux Security Page

  Infilsec   Ư ÷  ִ ˷ִ
   (vulnerability engine) ִ.  Infilsec vunerability
  engine

  CIAC  ħ ǵ鿡     ش.
  CIAC  bulitins

  7.3.  ϸ Ʈ

  Bugtraq:  bugtraq Ϸ,  subscribe bugtraq Ἥ
  listserv@netspace.org email  ȴ. (  
   ũ ).

  CIAC:  ( ) subscribe ciac-bulletin Ἥ
  majordomo@tholia.llnl.gov e-mail .

  7.4.  å - μ Ÿ.

       ִ.    ̷ å 
  ݸ ϰ Ѵ.    ٷ å  ƴ϶, ý
     å ȿ ؼ ٷ ִ.

  Building Internet Firewalls By D. Brent Chapman & Elizabeth D.  Zwicky

  1st Edition September 1995

  ISBN: 1-56592-124-0

  Practical UNIX & Internet Security, 2nd Edition By Simson Garfinkel &
  Gene Spafford

  2nd Edition April 1996

  ISBN: 1-56592-148-8

  Computer Security Basics By Deborah Russell & G.T. Gangemi, Sr.

  1st Edition July 1991

  ISBN: 0-937175-71-4

  Linux Network Administrator's Guide By Olaf Kirch

  1st Edition January 1995

  ISBN: 1-56592-087-2

  PGP: Pretty Good Privacy By Simson Garfinkel

  1st Edition December 1994

  ISBN: 1-56592-098-8

  Computer Crime A Crimefighter's Handbook By David Icove, Karl Seger &
  William VonStorch (Consulting Editor Eugene H. Spafford)

  1st Edition August 1995

  ISBN: 1-56592-086-4

  8.  

   溸 ϸ Ʈ ϰ ֽ ⿡ ν 
   ǻ͸ ϰ ϱ      ִ.  
  ϵ鿡 Ǹ ̰, tripwire  α׷ 
  ϸ   ϵ   ִ.

   ǻͿ   ǻ  ϱⰡ 
  ʴ.   ǻͿ    ʿ,  Ƿ
   ÷   ִ.   ߵǴ Ư , 
  ü   Ȱ ׵ ´.   
  ʿϴٸ ߸ ̻ ÷̴.

  9.   

   ۿ Ұ   ڷκ  ̴.  
  Ȥ    Ʒ 鿡 Ѵ.

       Rob Riggs <rob@DevilsThumb.com>
       S. Coffin <scoffin@netcom.com>

