Re: [Haskell-cafe] How to use an crypto with hackage cereal?

I see. Thank you. So I will find other solutions. On Wed, Apr 22, 2015 at 12:01 PM, Ivan Lazar Miljenovic < ivan.miljenovic@gmail.com> wrote:

On 22 April 2015 at 13:58, Magicloud Magiclouds wrote:

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Ah, sorry, the "encode" function is the one from cereal, not to "generate a particular encoding for a value".

I meant "encode" as in "use a specific representation rather than directly converting it on a constructor-by-constructor basis as is the default for Get/Put".

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On Wed, Apr 22, 2015 at 11:56 AM, Ivan Lazar Miljenovic wrote:

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On 22 April 2015 at 13:52, Magicloud Magiclouds wrote:

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Say the data structure is:

data Person = Person { name :: String , gender :: Gender , age :: Int }

Then the process to generate the binary is:

msum $ map (encrypt . encode) [ length $ name person, name person, gender person, age person ]

Above process is just persudo in Haskell, the actual is not coded in Haskell.

Except that binary and cereal are for serializing Haskell values directly; you seem to be wanting to parse and generate a particular encoding for a value. In which case, I don't think binary or cereal is really appropriate.

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On Wed, Apr 22, 2015 at 11:44 AM, Andrey Sverdlichenko <

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wrote:

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Could you describe encrypted data format? I can't understand problem with decryption.

On Tue, Apr 21, 2015 at 8:41 PM, Magicloud Magiclouds wrote:

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That is the ugliness of the original binary data. The encryption is not by fixed block size. So decrypt cannot be run before the get*

helpers.

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So decrypt-runGetPartial-decrypt-runGetPartial loop would not work.

I need a "post process" in Get. For example, "portNumber <- liftM decrypt getWord16be; return $ MyDataType portNumber". But currently I could not pass decrypt into get function.

On Wed, Apr 22, 2015 at 11:26 AM, Andrey Sverdlichenko wrote: > > You can't really modify source bytestring inside Get monad, and

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> is > what decryption effectively do. The only option I know about is to > run > another parser inside Get monad. I'd rather write > decrypt-runGetPartial-decrypt-runGetPartial loop and return Fail from > it on > decryption error. > > > > On Tue, Apr 21, 2015 at 8:12 PM, Magicloud Magiclouds > wrote: >> >> How about fail in Get monad if decrypt failed? So decrypt failure >> would >> lead to a result of "Left String" on decode. >> >> On Wed, Apr 22, 2015 at 11:05 AM, Andrey Sverdlichenko >> >> wrote: >>> >>> You probably should not merge decrypt and decode operations, it is >>> bad >>> crypto habit. Until you decrypted and verified integrity of data, >>> parsing is >>> dangerous and opening your service to attacks. Correct way of >>> implementing >>> this would be to pass ciphertext to decryption function and run >>> parser only >>> if decryption is successful. If bytestring is too big to be >>> decrypted in one >>> piece, consider encrypting it in blocks and feeding decrypted

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>>> to >>> parser. >>> >>> >>> >>> On Tue, Apr 21, 2015 at 7:49 PM, Magicloud Magiclouds >>> wrote: >>>> >>>> Similar as you envisaged. I would receive a bytestring data and a >>>> config point out what cipher to use. Then I deserialize the data >>>> to a data >>>> type with some fields. The serialize process is something like: >>>> >>>> msum $ map (encrypt . encode) [field1, field2, field3] >>>> >>>> I could parse the bytestring outside Get/Put monads. But I think >>>> that >>>> looks ugly. I really want to embed the decrypt process into >>>> Get/Put monads. >>>> >>>> On Tue, Apr 21, 2015 at 10:08 PM, Ivan Lazar Miljenovic >>>> wrote: >>>>> >>>>> On 21 April 2015 at 23:58, Magicloud Magiclouds >>>>> wrote: >>>>> > Thank you. But how if the cipher was specified outside the >>>>> > binary >>>>> > data? I >>>>> > mean I need to pass the decrypt/encrypt function to get/put >>>>> > while >>>>> > they do >>>>> > not accept parameters. Should I use Reader here? >>>>> >>>>> Maybe you could explain what you're doing better. >>>>> >>>>> I would envisage that you would get a Bytestring/Text value,

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>>>>> encrypt/decrypt and then put it back (though if you're dealing >>>>> with >>>>> Bytestrings, unless you're wanting to compose them with others >>>>> there's >>>>> no real need to use Get and Put as you'll have the resulting >>>>> Bytestring already...). >>>>> >>>>> Or are you wanting to implement your own encryption/decryption >>>>> scheme? >>>>> In which case, you might want to either: >>>>> >>>>> a) write custom functions in the Get and Put monads OR >>>>> >>>>> b) write custom parsers (e.g. attoparsec) and builders (using

blaze@ruddy.ru> this parts then the

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>>>>> Builder module in bytestring); this is probably going to suit you >>>>> better. >>>>> >>>>> > >>>>> > On Tue, Apr 21, 2015 at 6:43 PM, Yitzchak Gale < gale@sefer.org> >>>>> > wrote: >>>>> >> >>>>> >> Magicloud Magiclouds wrote: >>>>> >> > I am trying to work with some binary data that encrypted by >>>>> >> > field >>>>> >> > instead of >>>>> >> > the result of serialization. I'd like to use Data.Serialize >>>>> >> > to >>>>> >> > wrap the >>>>> >> > data >>>>> >> > structure. But I could not figure out how to apply an >>>>> >> > runtime >>>>> >> > specified >>>>> >> > cipher method to the bytestring. >>>>> >> >>>>> >> Are you using the set of crypto libraries written by >>>>> >> Victor Hanquez, such as cryptocipher-types, >>>>> >> crypto-pubkey-types, and cryptohash? >>>>> >> >>>>> >> Or the set of libraries written by Thomas DuBuisson, >>>>> >> such as crypto-api, cipher-aes128, etc.? >>>>> >> >>>>> >> Here is an example of decoding for Victor's libraries. >>>>> >> Encoding would be similar using Put instead of Get. >>>>> >> Thomas' libraries would be similar using the other >>>>> >> API. >>>>> >> >>>>> >> Let's say you have a type like this: >>>>> >> >>>>> >> data MyCipher = MyAES | MyBlowfish | ... >>>>> >> >>>>> >> Then in your cereal code you would have a Get monad >>>>> >> expression something like this (assuming you have >>>>> >> written all of the functions called parseSomething): >>>>> >> >>>>> >> getStuff = do >>>>> >> cipher <- parseCipher :: Get MyCipher >>>>> >> clearText <- case cipher of >>>>> >> MyAES -> do >>>>> >> keyBS <- parseAESKey :: Get ByteString >>>>> >> let key = either (error "bad AES key") id $ makeKey >>>>> >> keyBS >>>>> >> cipher = cipherInit key >>>>> >> cipherText <- parseAESCipherText :: Get ByteString >>>>> >> return $ ecbDecrypt cipher cipherText >>>>> >> MyBlowfish -> do ... >>>>> >> >>>>> >> etc. >>>>> >> >>>>> >> Hope this helps, >>>>> >> Yitz >>>>> > >>>>> > >>>>> > >>>>> > >>>>> > -- >>>>> > 竹密岂妨流水过 >>>>> > 山高哪阻野云飞 >>>>> > >>>>> > And for G+, please use magiclouds#gmail.com. >>>>> > >>>>> > _______________________________________________ >>>>> > Haskell-Cafe mailing list >>>>> > Haskell-Cafe@haskell.org >>>>> > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe >>>>> > >>>>> >>>>> >>>>> >>>>> -- >>>>> Ivan Lazar Miljenovic >>>>> Ivan.Miljenovic@gmail.com >>>>> http://IvanMiljenovic.wordpress.com >>>> >>>> >>>> >>>> >>>> -- >>>> 竹密岂妨流水过 >>>> 山高哪阻野云飞 >>>> >>>> And for G+, please use magiclouds#gmail.com. >>> >>> >> >> >> >> -- >> 竹密岂妨流水过 >> 山高哪阻野云飞 >> >> And for G+, please use magiclouds#gmail.com. > >

-- 竹密岂妨流水过 山高哪阻野云飞

And for G+, please use magiclouds#gmail.com.

-- 竹密岂妨流水过 山高哪阻野云飞

And for G+, please use magiclouds#gmail.com.

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

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com

-- 竹密岂妨流水过 山高哪阻野云飞

And for G+, please use magiclouds#gmail.com.

-- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com http://IvanMiljenovic.wordpress.com

-- 竹密岂妨流水过 山高哪阻野云飞 And for G+, please use magiclouds#gmail.com.