Difference between revisions of "Obfuscation"
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DonStewart (talk | contribs) (A page on obfuscating Haskell code) |
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| − | = Obfuscation = |
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| − | |||
Haskell is (perhaps surprisingly) an excellent language for code |
Haskell is (perhaps surprisingly) an excellent language for code |
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obfuscation. There have been three Haskell obfuscation contests: |
obfuscation. There have been three Haskell obfuscation contests: |
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| + | * [http://www.haskell.org/pipermail/haskell/2004-August/014387.html 1993 Bottomth Obfuscation Haskell Contest] |
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| − | * Pred Zeroth (early 1990s?) |
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| − | + | * [http://web.archive.org/web/20060103040156/http://iohc.mgoetze.net/ 2003 Zeroth Obfuscated Haskell Contest] |
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| − | + | * [http://web.archive.org/web/20060107141532/http://www.scannedinavian.org/iohcc/succzeroth-2004/ 2004 Succ Zeroth Obfuscated Haskell Contest] (2004 IOHCC [[Obfuscation/IOHCC 2004|announcement]]) |
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The ability to use symbols for identifiers helps a lot of course, as |
The ability to use symbols for identifiers helps a lot of course, as |
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| − | does suspending the use of layout. |
+ | does suspending the use of layout. [[Pointfree]] style is also an |
| + | excellent help. Use of strange monads and [[type arithmetic]] can all be |
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| − | + | very confusing. Finally, Haskell's clean semantics makes refactoring |
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| − | (semi-)mechanical, leading to some interesting obfuscated encodings |
+ | code (semi-)mechanical, leading to some interesting obfuscated encodings |
| − | can |
+ | (one can replace most Haskell keywords with lambda abstractions, for |
| + | example). |
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== Example == |
== Example == |
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| Line 20: | Line 20: | ||
this case multiple '?' characters), Haskell may be highly obfuscated. |
this case multiple '?' characters), Haskell may be highly obfuscated. |
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| + | <haskell> |
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-------------------------------------------- |
-------------------------------------------- |
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module Main where{import List;import System; |
module Main where{import List;import System; |
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| Line 58: | Line 59: | ||
;(?????????????)(???)=(((readFile)((???))))} |
;(?????????????)(???)=(((readFile)((???))))} |
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-------------------------------------------- |
-------------------------------------------- |
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| + | </haskell> |
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[[Category:Idioms]] |
[[Category:Idioms]] |
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| + | [[Category:Contests]] |
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Latest revision as of 18:50, 17 May 2008
Haskell is (perhaps surprisingly) an excellent language for code obfuscation. There have been three Haskell obfuscation contests:
- 1993 Bottomth Obfuscation Haskell Contest
- 2003 Zeroth Obfuscated Haskell Contest
- 2004 Succ Zeroth Obfuscated Haskell Contest (2004 IOHCC announcement)
The ability to use symbols for identifiers helps a lot of course, as does suspending the use of layout. Pointfree style is also an excellent help. Use of strange monads and type arithmetic can all be very confusing. Finally, Haskell's clean semantics makes refactoring code (semi-)mechanical, leading to some interesting obfuscated encodings (one can replace most Haskell keywords with lambda abstractions, for example).
Example
The following illustrates how, by turning off layout, rewriting keywords (let, case, where) as lambdas, and using symbols for identifiers (in this case multiple '?' characters), Haskell may be highly obfuscated.
--------------------------------------------
module Main where{import List;import System;
import Data.HashTable as H;(???????)=(concat
);(??????)(???)(????)=((groupBy)(???)(????))
;(??????????????????????)(????)=((??????????
)((tail).(???????))((????????????????????)((
??????)(?????????????????????)(????))));(??)
=([' ']);(??????????????)=((hashString));(?)
=((>>=));(???????????????????????)([((???)),
(????)])=((?????????????)(???))?(\(?????)->(
(????????????????)(==)(??????????????))?(\((
???))->((??????????????????)(???????????????
)(???)(?????))>>((?????????????????)(???))?(
\((?????))->((((???????????????????)((????))
((??????????????????????))((?????))))))));((
???????????????????????))(??)=(????????????)
("usage f dic out");(?????????????????????)(
(???),(??????))((????),(????????????????????
))=((???)==(????));(?????????????????)(???)=
(toList)(???);(????????????????????)(????)=(
((??????????)(((??????????)(snd)))((????))))
;(??????????????????)(???????????????)(???)(
(?????))=(((mapM)(((???????????????)(???)))(
(lines)(?????))));(???????????????????)(????
)(???????????????????????)(?????)=(?????????
)(????)((unlines)((???????????????????????)(
?????)));(????????????????)(???)((????))=(((
new)(???)(????)));(main)=((???????????)?(((\
(???)->((???????????????????????)(???))))));
(???????????????)(???)(????)=((????????)(???
)((sort)(????))((??)++(????)));(???????????)
=(getArgs);(????????????)(???)=((((print))((
???))));(??????????)(???)(????)=(((map)(???)
(????)));(????????)((???))(????)(?????)=((((
H.insert))((???))(????)(?????)));(?????????)
((???))((????))=(((writeFile)(???)((????))))
;(?????????????)(???)=(((readFile)((???))))}
--------------------------------------------