 From : Peter Sobolev                       2:5030/84       Sun 28 Apr 96 16:50
 Subj : ? What does it mean?

==RU.HACKER=FAQ===============================================================

13. ⠪ Cobra?
-------------------

p뢠   ᯥ祭 ᭮ .

       ⭨ p
0. p
   , .

1. p稪
1.1 . H 
    㤠p⢥ 筮-᫥⥫᪨  p
     ⥫㠫樨 ᫮ ⥬ p  (    ).
1.2 H "" . pp 筮-p⢥ 
    "p᭠ p"

2. p樨 ᯥp
    . ..᪮ ( 㯮祭 ᒥ劮ᨥ)
   H ( 㯮祭  )
   p  p樨 p  ( 㯮祭  )
    p⨪ . ..誮 ( ᨬ ᯥp)
   p ⮬⠈p
   / 51105
   業p ქp
    H 

pp   4-  饭.
p䨪 N20  22  1995. ⢨⥫  31 p 1998.

 p  -  pp      ⠭   p  ⨯
IBM-PC  (   ⮫,  p⨢,   p  ),   p騩  
p DOS 3.3   p. (   WIN-95 p   p⠥.   
  16-  pp來.  32-  pp來        p  
pp襭  p樨)  p   ᯥ稢  p     
p ﬨ  짮⥫ -   ,  ⮫쪮 ⥭,
  㯠,   㯥p  (pp筮   p)      ᪨
p(A..Z).樮p      COM     LPT  (     p
p墠 pp뢠 ).  짮⥫ ᯥ稢  p
    p   ⠭묨  ﬨ.  
ᯥ祭  p  짮⥫     p祭  ⢮   ᪥,
pp pp. p  ⮬, p 栬  p
  ⠪  ᪥  㯭,    짮⥫    ᬮ p 
   ᪥   p㤥p pp. p  ᯮᮡ
p㦨  p  ⠪    砩    pp   ᪠
pp    .  ,  ⠪,      p 짮⥫ 
p.   p  ⮬᪨  ⠭  p   ⠫
p p.  p  10    500  ᪥.  p
pp p樨   5/  PC-486.  㭪樮p ᮢ⭮
 WINDOWS 3.X, dBASE, FoxPro, Clipper etc.
  祭 ᯥp⮢:
   - p⮩ p室 DES
  ⭨ - "p  p訬 p⮣p᪨ ᢮⢠
    ⮩ ~10^22 ⭮⥫쭮  ⮤ p⮠"
    -  訩   ⮤  ⠭     p     ᢮
   p樨  10^10    p⥪      ⠪     ꥬ
   p⮣ ⥪, p㤮 p樨 ⠢  ⮬ 砥  10^12
   p樨.  H室 ꥬ   ⠭  -  10^10
   .     業    p⮩  p p
   p㤮 100..120 祫..  p⥫쭮 1.5-2 .

 p,   p.    ᭮  PC  H   p 
p⮣p᪮  pp  p樨.  p  p 
p室 p   p⠭     p⭮   
p⠬ p.   p    p  ᪥  
p  13-  pp뢠  (  ᥪp  p), ⠪  ⠫ 
䠩.  ,  pp 砥 樮쭮.
 ᯥ稢            p⮢         -
p⮤pp.     pp  p㦠  p   config.sys. 
p      p  -    p  室   PC.  pp
⮢  ᯨ᮪  ppp  p    砥  master-p
()   p᪨ ⥫  p.    p   
᢮   p,         㬠.    Master-p      ⮫쪮
pp.     p  ⮬  ᭮    䨪樨  MBR,  
p ᭮.    p⨢⢨  ⠪ ⠪   p  
   祭   pp筮   p   p.         ⮣
p  master-p    12- .   
p  ⢫ 3-  4- p室 p. p  p⪮
p  ,   筥  pp⨪,   ᣥpp      
 ᤥ  p  p室  p㥬   ( ᥪp
p ),   뫮     ᭥ᥭ. ,  ᭮ᨢ訥 p
p室  p  ᪠,         p室   
.
 ⢥,  p  p p, p㧨   ᪥
p㤥p  㢨  p⮣p.      p   㯠  p   
p樨, p ⮬,    p  쭮  ⮦,  pp
   ᯥ樠 p  ᪨ ᪨  pp 
 32 ⨯    DiskReet.   쪮 p    p  p
p ⥬     p  p訢. p p  ᪠
 p  p p㧪 p -  祢  ᪥
    .     ᫥  砥    p  p   
p,    ᭨  饭  p.     筮
,       ⥫   p  ⢫      
master-p , ᮮ⢥⢥, p , ⠪    ⥬  ,
,  묨  ﬨ.  祬    __? p ⠫樨
p      ⮫쪮   p -  obra,   ᨬ묨
ﬨ. pp    Cobra  ᮧ   p,
  ᨬ   p p Cobra.
 ,  p  p  ⠪   ⠫,   p
 pp筮 p 䠩 (  ⨫ Lock.exe ).  ⠢  p
室,  ⠪      ᯥ樠쭠  ⨫  Safe.exe  p   
p ᯥ樠쭮 㪠 䠩.
 p p㧪 p 룫廊 ᫥騬 p. H᪮쪮   ᬮ
pp    MBR'  p  p  (int 9), ⠪  
Shift   p⠥.   , ᮢp  ,    - p 
p 㯥 .   ᠬ  -   ⠭  
 p㧪  ᪥ p    ,   ,   
Shift, ⢥,   ⪫祭     ⪫祭 㦭   
Config.sys  switches.    ⮫쪮 砥    p㧪  
᪥, ⠪   㦥  稭 䨪  MBR ,  ᮮ⢥⢥,
p墠  p.          ⢮p   ᪨
p  p    p  p      .   H
p  p    ⠪  ⢮p  ᥪp ᪨
p.  H        p     蠥  p
⠫.   ,   p 㯥  p⮣p᪨ pp
p 㯥  䠩.
 p p  p㧪.   Config.sys p㦠 p⮤pp  -
p  ⥬  .   p  pp    autoexec.bat  뢠
pp  Cobra.exe     pp           p
  㯠.   p  ᪮  窨  ( Hp⮭,  
Win)  뢠  pp  Cobratst.exe,  p  pp,    
p㧨            pp   p       ᠭ
pp.       pp  p    p
䠩  p   楫⭮ ᫥騬  p:    CRC
砫      䠩     p    .   ᫨   
p宦,  砫   ⠭   .   
pp BIOS   pp,  p.
 , p ⠫樨 p  p⮤pp  㯮 p뢠  
,   ᯥ樠 p  ⮢.   ⮣ ᯮ, 宦
HD  Serial  Number.      p      p     p㣮
p   ᫥ p  㤠.
 , ⠪    䠩  Config.Sys etc  㯭 p
⮫쪮   ⥭, ⠪     祭 p     ᬮ.
 ᮡ p p   ᬨp⥫쭠 p㡠誠 -  窠 ⨯
Hp⮭.    p  pp     p   
p      㯭    p    㯭 ⮫쪮 
, p  pp襭 ᪠.      pp襭  -  
p p饭.   p᭮  ⮩ 窥 ,    p
室  DOS   p㣨 pp  p     command.com,   
  .
 p p.  p   p ⥣p  p - 㯥p짮⥫,
  pp襭      設   - ⠭, ᪮䨣pp 
⪠  p,    p,     p  p 㯠
etc, pp,  pp襭   , p   ⪠ p,
pp, p  ⮫쪮  ᢮ ⥫ p  
, p 祣  p   .

                      ""
                 ਬ ஢ 512  ⥪

       ஢ ⮨  ᪮쪨 ᭮ ᫥⥫ 楤,
        믮  । 浪  ࠧ 砫
       ᫮ (祭 U, Y, Co, K1)
    祭:
       Ti  Ci - i-    ᨬ 室 ⥪  ,
                  ।⠢ 塠⮢ ᫮;
       Fm(Ui), Fc(Yi), F(Ui), Fm(Yi) - 祭  祢 ⮢
                ࠬ Ui  Yi,   m  c;
       K1 - ⠭, ।塞 ஫;
       Cl - 訩  塠⮢ ᫠ ⮡ࠦ饣  ᨬ;
       Ch - 訩  塠⮢ ᫠ ⮡ࠦ饣  ᨬ.

       <  m >             Fc
       ͻͻͻͻͻͻͻͻͻ
       ͼͼͼͼͼͼͼͼͼ
          Fm              <  c >

    騩   384  ࠧ      257 .
    -------------------------------------------------------------------

     1- 楤. (祭 室 ᨬ ஭㬥஢
    =======================               ⭮ ᫥⥫쭮)
   1. ⠭ 祭 稪 i=1   砫 
      㪠⥫ U, Y  1    㭪 f1  ஫.
   2. ⢨ ८ࠧ i-⮩  室 ᨬ:

             C'i = (Ti - K1) XOR Fm(Ui-1 mod 256)

   3. ᫨  祭 㪠⥫ U  Y:

             Ui  = (Ui-1 mod 256) XOR Fc(Yi-1 mod 256)
             i  = (i-1 mod 256)+ Cl'i

   4.  ८ࠧ i-⮩  室 ᨬ:

             Ci =  C'i + Ui

   5. ⠭ i=i+1. ᫨ i<=256,  ३  .2,  .
   ------------------------------------------------------------------

     2- 楤. (祭 室 ᨬ ஭㬥஢
    =======================                אַ ᫥⥫쭮)
   1. ⠭ 祭 稪 i=1   砫 
      㪠⥫ U, Y   㭪 f2  ஫.
   2. ⢨ ८ࠧ i-⮩  室 ᨬ:

             C'i = Ti XOR F(Ui-1 mod 256)

   3. ᫨  祭 㪠⥫ U  Y:

             Ui  = (Ui-1 mod 256) XOR Fm(Yi-1 mod 256)
             i  = (i-1 mod 256)+ Ch'i

   4.  ८ࠧ i-⮩  室 ᨬ:

             Ci =  C'i + Ui

   5. ⠭ i=i+1. ᫨ i<=256,  ३  .2,  .
   ----------------------------------------------------------------

     3- 楤. (祭 室 ᨬ ஭㬥஢
    =======================              ⭮ ᫥⥫쭮)

   1. ⠭ 祭 稪 i=1   砫 
      㪠⥫ U, Y     㭪 f3  ஫.
   2. ⢫ ८ࠧ i-⮩  室 ᨬ:

          C'i = (Ti + C'i-1)  XOR  Fm(Ui-1 mod 256)

   3. ᫨  祭 㪠⥫ U  Y:

          Yi = Yi-1 + Cl'i-1
          Ui = ((Ui-1 mod 256) XOR Fc(Yi mod 256)) + Ch'i-1

   4.  ८ࠧ i-⮩  室 ᨬ:

          Ci =  C'i + Ui

   5. ⠭ i=i+1. ᫨ i<=256,  ३  .2,  .
   ----------------------------------------------------------------

     4- 楤. (祭 室 ᨬ ஭㬥஢
    =======================                אַ ᫥⥫쭮)

   1. ⠭ 祭 稪 i=1   砫 
      㪠⥫ U, Y     㭪 f4  ஫.
   2. ⢫ ८ࠧ i-⮩  室 ᨬ:

          C'i = (Ti + C'i-1)  XOR  F(Ui-1 mod 256)

   3. ᫨  祭 㪠⥫ U  Y:

          Yi = Yi-1 + Ch'i-1
          Ui = ((Ui-1 mod 256) XOR Fm(Yi mod 256)) + Cl'i-1

   4.  ८ࠧ i-⮩  室 ᨬ:

          Ci =  C'i + Ui

   5. ⠭ i=i+1. ᫨ i<=256,  ३  .2,  .
   ----------------------------------------------------------------

            ⥫쭠 p
           --------------------------
    祭 ⥬ "p" ꥪ⮢    
  p  ᮧ ᢮ 祢 ⥬, 
 室 p p ᫮ p祭 ⭮ ⥪.

   冷 믮 ᭮ ᫥⥫ 楤 p-
    ⠯ ⥭䨪樨 짮⥫ p pp p-
   堭  p⮣p᪨ pp  ᨬ  
  ॡ㥬 ਯ⮩  pᬠp ᫥騥 p:

       Ŀ
                                 楤.
         楤    楤  楤 ࢠ 
       Ĵ
        1- 2+ 3- 4+   1- 2+ 3-     1- 2+        *1- 2+    
        2+ 3- 4+ 1-   2+ 3- 4+     2+ 3-        *2+ 3-    
        3- 4+ 1- 2+   3- 4+ 1-     3- 4+        *3- 4+    
        4+ 1- 2+ 3-   4+ 1- 2+     4+ 1-        *4+ 1-    
        1- 4+ 3- 2+   1- 4+ 3-     1- 4+        *1- 4+    
        4+ 3- 2+ 1-   4+ 3- 2+     4+ 3-        *4+ 3-    
        3- 2+ 1- 4+   3- 2+ 1-     3- 2+        *3- 2+    
        2+ 1- 4+ 3-   2+ 1- 4+     2+ 1-        *2+ 1-    
        1- 2+ 1f- 2f+ 1- 2+ 1f-                           
        1- 2+ 1f- 4+                                      
        1- 2+ 3-  2f+                                     
        1- 4+ 1f- 2+  1- 4+ 1f-                           
        1- 4+ 1f- 4f+                                     
        1- 4+ 3-  4f+                                     
        2+ 1- 2f+ 1f- 2+ 1- 2f+                           
        2+ 1- 2f+ 3-                                      
        2+ 1- 4+  1f-                                     
        2+ 3- 2f+ 1-  2+ 3- 2f+                           
        2+ 3- 2f+ 3f-                                     
        2+ 3- 4+  3f-                                     
        3- 2+ 1-  2f+                                     
        3- 2+ 3f- 2f+ 3- 2+ 3f-                           
        3- 2+ 3f- 4+                                      
        3- 4+ 1-  4f+                                     
        3- 4+ 3f- 2+  3- 4+ 3f-                           
        3- 4+ 3f- 4f+                                     
        4+ 1- 2+  1f-                                     
        4+ 1- 4f+ 1f- 4+ 1- 4f+                           
        4+ 1- 4f+ 3-                                      
        4+ 3- 2+  3f-                                     
        4+ 3- 4f+ 1-  4+ 3- 4f+                           
        4+ 3- 4f+ 3f-                                     
       
   ,  p 砥 p ᭮ p楤p;
     '-'  '+' p p⪨ ᫥⥫쭮 ᨬ;
     f - 䨪 㭪樨  p  ᫥ 砫
               祭  ⠭ ᯮ㥬  ᭮ p楤p;
     '*' 砥,  ⮩ 楤ன ࠡ뢠 ⮫쪮
              室 ᫥⥫쭮 ᨬ;
