The apache-md5 package

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Haskell implementation of Apache HTTP server specific MD5 digest algorithm that uses OpenSSL MD5() function.

For usage example see Data.Digest.ApacheMD5 module or GitHub README.

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Dependenciesbase (==4.*), bytestring (==0.10.*), deepseq (>= [details]
Copyright(c) 2009, 2010, 2012-2015 Peter Trško
AuthorPeter Trško <>
CategoryData, Cryptography
Home page
Bug tracker
Source repositoryhead: git clone git://
this: git clone git:// v0.6.1.1)
UploadedTue Jan 6 22:49:27 UTC 2015 by PeterTrsko





Pass additional warning flags to GHC.


Define instance of NFData for Salt newtype. This dependency is enforced for benchmark.


Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info


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Readme for apache-md5-

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Apache MD5

Hackage Haskell Programming Language BSD3 License


Haskell implementation of Apache specific MD5 digest algorithm that uses OpenSSL MD5.


Stable releases with API documentation are available on Hackage.


Requires OpenSSL library with header files. On Debian and Ubuntu Linux it's provided by libssl-dev package that can be installed using apt-get:

$ apt-get install libssl-dev

For more see apt-get(8) manual page or e.g. Ubuntu Documentation: AptGet Howto.

After that just use cabal-install as you would normally do. For details see HaskellWiki: How to install a Cabal package.

Building Options


Create htpasswd like entry and print it to stdout:

module Main (main)

import Control.Applicative ((<$>))
import System.Environment (getArgs, getProgName)
import System.Exit (exitFailure)
import System.IO (hPutStrLn, stderr)

import Control.Monad.Random (evalRandIO, getRandomRs)
    -- MonadRandom package
import Data.ByteString (ByteString)
import qualified Data.ByteString as BS (index, pack)
import qualified Data.ByteString.Char8 as C8 (concat, pack, putStrLn, singleton)
    -- bytestring package
import Data.Digest.ApacheMD5 (Salt, apacheMD5, mkSalt, unSalt)
import Data.Digest.ApacheMD5.Internal (alpha64)

htpasswdEntry :: String -> String -> Salt -> ByteString
htpasswdEntry username password salt = C8.concat
    [ C8.pack username
    , C8.pack ":$apr1$"
    , unSalt salt
    , C8.singleton '$'
    , apacheMD5 (C8.pack password) salt

genSalt :: IO Salt
genSalt = do
    Just s <- evalRandIO $ mkSalt . BS.pack . map (BS.index alpha64) . take 8
        <$> getRandomRs (0, 63)
        -- We know that Salt is correctly generated, since we use alpha64 to do
        -- it. That is the reason why we can pattern match on Just.
        -- Other option would be to use Salt value constructor from
        -- Data.Digest.ApacheMD5.Internal module.
    return s

main :: IO ()
main = do
    args <- getArgs
    progName <- getProgName
    case args of
        [userName, password] ->
            genSalt >>= C8.putStrLn . htpasswdEntry userName password
        _ -> do
            hPutStrLn stderr $ "Usage: " ++ progName ++ " USER_NAME PASSWORD"

Compiling and running above example:

$ ghc -Wall example.hs
[1 of 1] Compiling Main             ( example.hs, example.o )
Linking example ...
$ ./example
$ ./example foo 123456

Unit Tests

Requires htpasswd command line utility installed. On Debian and Ubuntu Linux it is provided by apache2-utils package that can be installed using apt-get:

$ apt-get install apache2-utils

For more see apt-get(8) manual page or e.g. Ubuntu Documentation: AptGet Howto.

To run tests use command similar to this:

$ cabal configure --enable-tests && cabal build && cabal test


This package provides Criterion benchmarks, to run them you can use something like:

$ cabal configure --enable-benchmarks && cabal build && cabal bench

To generate HTML output one needs to specify output file. Then the last command in above chain would look like:

$ cabal bench --benchmark-option=--output=benchmarks.html

Where benchmarks.html is the name of Criterion generated HTML file.


Contributions, pull requests and bug reports are welcome! Please don't be afraid to contact the author.