Here's a working example: import qualified Codec.Crypto.RSA as Crypto import System.Random (mkStdGen) import Data.Binary (encode) import Data.ByteString.Lazy.UTF8 (toString) n = 1024 (pubKey,privKey,_) = Crypto.generateKeyPair (mkStdGen n) n encrypt :: (Data.Binary.Binary a) => a -> Data.ByteString.Lazy.Internal.ByteString encrypt str = fst $ Crypto.encrypt (mkStdGen n) pubKey (encode str) decrypt :: Data.ByteString.Lazy.Internal.ByteString -> String decrypt = toString . Crypto.decrypt privKey Thus, decrypt $ encrypt "haskell" = "\NUL\NUL\NUL\NUL\NUL\NUL\NUL\ahaskell" I'm using Codec.Crypto.RSA and you're quoting Codec.Encryption.RSA, which is not the same thing; unfortunately I need to use RSAES-OAEP (SHA1) so I guess I have to stick with Codec.Crypto.RSA. Any ideas? -- Cp On Sat, Nov 20, 2010 at 12:50, Dominic Steinitz wrote:

Charles-Pierre Astolfi writes:

...

Hi -cafe,

I have a question about Codec.Crypto.RSA: how to enforce that (informally) decrypt . encrypt = id Consider this code:

That's certainly what I would expect and one of the unit tests  that comes with http://hackage.haskell.org/packages/archive/Crypto/4.2.2/doc/html/Codec-Encr... checks for this. I wasn't able to get you code to compile so I couldn't investigate further. Maybe you could post a fully compiling example?

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The problem in this example is the use of Data.Binary. When using Data.ByteString.Lazy.Char8 instead, the problem does not exist. import qualified Codec.Crypto.RSA as Crypto import System.Random (mkStdGen) import Data.ByteString.Lazy.UTF8 (toString) import qualified Data.ByteString.Lazy.Char8 as C8 import qualified Data.ByteString.Lazy n = 1024 (pubKey,privKey,_) = Crypto.generateKeyPair (mkStdGen n) n encrypt :: String -> Data.ByteString.Lazy.ByteString encrypt str = fst $ Crypto.encrypt (mkStdGen n) pubKey (C8.pack str) decrypt :: Data.ByteString.Lazy.ByteString -> String decrypt = toString . Crypto.decrypt privKey decrypt $ encrypt "haskell" = "haskell" Regards, Mathias Am 20.11.2010 13:15, schrieb Charles-Pierre Astolfi:

...

Here's a working example:

import qualified Codec.Crypto.RSA as Crypto import System.Random (mkStdGen) import Data.Binary (encode) import Data.ByteString.Lazy.UTF8 (toString)

n = 1024 (pubKey,privKey,_) = Crypto.generateKeyPair (mkStdGen n) n

encrypt :: (Data.Binary.Binary a) => a -> Data.ByteString.Lazy.Internal.ByteString encrypt str = fst $ Crypto.encrypt (mkStdGen n) pubKey (encode str)

decrypt :: Data.ByteString.Lazy.Internal.ByteString -> String decrypt = toString . Crypto.decrypt privKey

Thus, decrypt $ encrypt "haskell" = "\NUL\NUL\NUL\NUL\NUL\NUL\NUL\ahaskell"

I'm using Codec.Crypto.RSA and you're quoting Codec.Encryption.RSA, which is not the same thing; unfortunately I need to use RSAES-OAEP (SHA1) so I guess I have to stick with Codec.Crypto.RSA. Any ideas? -- Cp

On Sat, Nov 20, 2010 at 12:50, Dominic Steinitz wrote:

...

...

Charles-Pierre Astolfi writes:

...

...

Hi -cafe,

I have a question about Codec.Crypto.RSA: how to enforce that (informally) decrypt . encrypt = id Consider this code:

That's certainly what I would expect and one of the unit tests that comes with http://hackage.haskell.org/packages/archive/Crypto/4.2.2/doc/html/Codec-Encr... checks for this. I wasn't able to get you code to compile so I couldn't investigate further. Maybe you could post a fully compiling example?

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

---

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Then how about using encode (as in your original example) and decode (both from Data.Binary). IMO it's garanteed that decode . encode = id (at least for the standard types). ... decrypt :: Data.ByteString.Lazy.ByteString -> String decrypt = decode . Crypto.decrypt privKey ... Am 21.11.2010 18:18, schrieb Charles-Pierre Astolfi:

Thanks Mat, it works, but I still have a problem: I'm heavily using Data.Binary.encode for various types (Int32, Int8, String, Bool...) and I don't know how I should manage this using Data.ByteString.Lazy.Char8.

-- Cp

On Sat, Nov 20, 2010 at 22:35, Mathias Weber wrote:

...

The problem in this example is the use of Data.Binary. When using Data.ByteString.Lazy.Char8 instead, the problem does not exist.

import qualified Codec.Crypto.RSA as Crypto import System.Random (mkStdGen) import Data.ByteString.Lazy.UTF8 (toString) import qualified Data.ByteString.Lazy.Char8 as C8 import qualified Data.ByteString.Lazy

n = 1024 (pubKey,privKey,_) = Crypto.generateKeyPair (mkStdGen n) n

encrypt :: String -> Data.ByteString.Lazy.ByteString encrypt str = fst $ Crypto.encrypt (mkStdGen n) pubKey (C8.pack str)

decrypt :: Data.ByteString.Lazy.ByteString -> String decrypt = toString . Crypto.decrypt privKey

decrypt $ encrypt "haskell" = "haskell"

Regards, Mathias

Am 20.11.2010 13:15, schrieb Charles-Pierre Astolfi:

...

Here's a working example:

import qualified Codec.Crypto.RSA as Crypto import System.Random (mkStdGen) import Data.Binary (encode) import Data.ByteString.Lazy.UTF8 (toString)

n = 1024 (pubKey,privKey,_) = Crypto.generateKeyPair (mkStdGen n) n

encrypt :: (Data.Binary.Binary a) => a -> Data.ByteString.Lazy.Internal.ByteString encrypt str = fst $ Crypto.encrypt (mkStdGen n) pubKey (encode str)

decrypt :: Data.ByteString.Lazy.Internal.ByteString -> String decrypt = toString . Crypto.decrypt privKey

Thus, decrypt $ encrypt "haskell" = "\NUL\NUL\NUL\NUL\NUL\NUL\NUL\ahaskell"

I'm using Codec.Crypto.RSA and you're quoting Codec.Encryption.RSA, which is not the same thing; unfortunately I need to use RSAES-OAEP (SHA1) so I guess I have to stick with Codec.Crypto.RSA. Any ideas? -- Cp

On Sat, Nov 20, 2010 at 12:50, Dominic Steinitz wrote:

...

Charles-Pierre Astolfi writes:

...

Hi -cafe,

I have a question about Codec.Crypto.RSA: how to enforce that (informally) decrypt . encrypt = id Consider this code:

That's certainly what I would expect and one of the unit tests that comes with

http://hackage.haskell.org/packages/archive/Crypto/4.2.2/doc/html/Codec-Encr... checks for this. I wasn't able to get you code to compile so I couldn't investigate further. Maybe you could post a fully compiling example?

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

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