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

Ah, sorry, the "encode" function is the one from cereal, not to "generate a particular encoding for a value". On Wed, Apr 22, 2015 at 11:56 AM, Ivan Lazar Miljenovic < ivan.miljenovic@gmail.com> wrote:

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

...

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.

...

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

...

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

...

...

decryption.

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

...

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.

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 this

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 < blaze@ruddy.ru> wrote: > > You probably should not merge decrypt and decode operations, it is bad > crypto habit. Until you decrypted and verified integrity of data,

...

...

...

...

...

> dangerous and opening your service to attacks. Correct way of implementing > this would be to pass ciphertext to decryption function and run

...

...

...

...

...

> if decryption is successful. If bytestring is too big to be decrypted in one > piece, consider encrypting it in blocks and feeding decrypted parts 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

with parsing is parser only 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, then >>> 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 the >>> Builder module in bytestring); this is probably going to suit you >>> better. >>> >>> > >>> > On Tue, Apr 21, 2015 at 6:43 PM, Yitzchak Gale >>> > 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.