-- hokey.hs: hOpenPGP key tool
-- Copyright © 2013-2014 Clint Adams
--
-- vim: softtabstop=4:shiftwidth=4:expandtab
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as
-- published by the Free Software Foundation, either version 3 of the
-- License, or (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-- GNU Affero General Public License for more details.
--
-- You should have received a copy of the GNU Affero General Public License
-- along with this program. If not, see <http://www.gnu.org/licenses/>.
{-# LANGUAGE DeriveFunctor, DeriveGeneric, FlexibleInstances #-}
import HOpenPGP.Tools.Common (banner, versioner, warranty)
import Codec.Encryption.OpenPGP.Expirations (getKeyExpirationTimesFromSignature)
import Codec.Encryption.OpenPGP.Fingerprint (fingerprint, eightOctetKeyID)
import Codec.Encryption.OpenPGP.KeyInfo (keySize)
import Codec.Encryption.OpenPGP.Signatures (verifyTKWith, verifySigWith, verifyAgainstKeys)
import Codec.Encryption.OpenPGP.Types
import Control.Applicative ((<$>),(<*>))
import Control.Arrow ((***), second)
import Control.Lens ((^.))
import Control.Monad.Trans.Writer.Lazy (execWriter, tell)
import qualified Crypto.Hash.SHA3 as SHA3
import qualified Data.Aeson as A
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as BC8
import qualified Data.ByteString.Lazy as BL
import qualified Data.ByteString.Base16 as Base16
import Data.Conduit (($=),($$), runResourceT)
import qualified Data.Conduit.Binary as CB
import Data.Conduit.Cereal (conduitGet)
import qualified Data.Conduit.List as CL
import Data.Conduit.OpenPGP.Keyring (conduitToTKsDropping)
import Data.List (unfoldr, elemIndex, findIndex, sortBy, intercalate)
import qualified Data.Map as Map
import Data.Maybe (fromMaybe, catMaybes, listToMaybe)
import Data.Monoid ((<>), mconcat)
import Data.Ord (comparing, Down(..))
import Data.Serialize (get)
import Data.Time.Clock.POSIX (getPOSIXTime, posixSecondsToUTCTime, POSIXTime)
import Data.Time.Format (formatTime)
import GHC.Generics
import Options.Applicative.Builder (command, footer, header, help, info, long, metavar, prefs, progDesc, showDefault, showHelpOnError, option, subparser, value)
import Options.Applicative.Extra (customExecParser, helper)
import Options.Applicative.Types (Parser)
import System.IO (Handle, hFlush, hPutStrLn, stderr, stdin, hSetBuffering, BufferMode(..))
import System.Locale (defaultTimeLocale)
import Text.PrettyPrint.ANSI.Leijen (colon, green, indent, linebreak, list, putDoc, red, text, yellow, (<+>), Doc) -- need 0.6.7 for hardline
data KAS = KAS {
pubkeyalgo :: Colored PubKeyAlgorithm
, pubkeysize :: Colored Int
} deriving Generic
data Color = Green | Yellow | Red
deriving Generic
data Colored a = Colored {
color :: Maybe Color
, explanation :: Maybe String
, val :: a
} deriving (Functor, Generic)
newtype FakeMap a b = FakeMap { unFakeMap :: [(a, b)] }
data KeyReport = KeyReport {
keyStatus :: String
, keyFingerprint :: TwentyOctetFingerprint
, keyVer :: Colored KeyVersion
, keyCreationTime :: TimeStamp
, keyAlgorithmAndSize :: KAS
, keyUIDsAndUAts :: FakeMap String UIDReport
} deriving Generic
data UIDReport = UIDReport {
uidSelfSigHashAlgorithms :: [Colored HashAlgorithm]
, uidPreferredHashAlgorithms :: [Colored [HashAlgorithm]]
, uidKeyExpirationTimes :: [Colored [TimeStamp]]
} deriving Generic
instance A.ToJSON KAS
instance A.ToJSON Color
instance (A.ToJSON a) => A.ToJSON (Colored a)
instance A.ToJSON KeyReport
instance A.ToJSON UIDReport
instance A.ToJSON b => A.ToJSON (FakeMap String b) where
toJSON = A.toJSON . Map.fromList . unFakeMap
instance A.ToJSON HashAlgorithm where
toJSON = A.toJSON . show
instance A.ToJSON PubKeyAlgorithm where
toJSON = A.toJSON . show
instance A.ToJSON KeyVersion where
toJSON DeprecatedV3 = A.toJSON (3 :: Int)
toJSON V4 = A.toJSON (4 :: Int)
instance A.ToJSON TwentyOctetFingerprint where
toJSON = A.toJSON . show
checkKey :: Maybe POSIXTime -> TK -> KeyReport
checkKey mpt key = KeyReport (either id (const "good") processedTK) (fingerprint $ key^.tkPKP) (colorizeKV (key^.tkPKP^.keyVersion)) (key^.tkPKP^.timestamp) (KAS (colorizePKA (key^.tkPKP^.pkalgo)) (colorizePKS (keySize (key^.tkPKP^.pubkey)))) (FakeMap (map (second uidr) (processedOrOrig^.tkUIDs) ++ map (uatspsToString *** uidr) (processedOrOrig^.tkUAts)))
where
processedOrOrig = either (const key) id processedTK
processedTK = verifyTKWith (verifySigWith (verifyAgainstKeys [key])) (fmap posixSecondsToUTCTime mpt) . stripOlderSigs . stripOtherSigs $ key
colorizeKV kv = uncurry Colored (if kv == V4 then (Just Green, Nothing) else (Just Red, Just "not a V4 key")) kv
colorizePKA pka = uncurry Colored (if pka == RSA then (Just Green, Nothing) else (Just Yellow, Just "not an RSA key")) pka
colorizePKS pks = uncurry Colored (colorizePKS' pks) pks
colorizePKS' pks
| pks >= 3072 = (Just Green, Nothing)
| pks >= 2048 = (Just Yellow, Just "Public key size between 2048 and 3072 bits")
| otherwise = (Just Red, Just "Public key size under 2048 bits")
colorizePHAs x = uncurry Colored (if fSHA2Family x < ei DeprecatedMD5 x && fSHA2Family x < ei SHA1 x then (Just Green, Nothing) else (Just Red, Just "weak hash with higher preference")) x
fSHA2Family = fi (`elem` [SHA512,SHA384,SHA256,SHA224])
ei x y = fromMaybe maxBound (elemIndex x y)
fi x y = fromMaybe maxBound (findIndex x y)
colorizeKETs ct ts kes
| null kes = Colored (Just Red) (Just "no expiration set") kes
| any (\ke -> realToFrac ts + realToFrac ke < ct) kes = Colored (Just Red) (Just "expiration passed") kes
| any (\ke -> realToFrac ts + realToFrac ke > ct + (5*31557600)) kes = Colored (Just Yellow) (Just "expiration too far in future") kes
| otherwise = Colored (Just Green) Nothing kes
sigissuer (SigVOther 2 _) = Nothing
sigissuer (SigV3 {}) = Nothing
sigissuer (SigV4 _ _ _ ys xs _ _) = listToMaybe . catMaybes . map (getIssuer . _sspPayload) $ (ys++xs) -- FIXME: what should this be if there are multiple matches?
sigissuer (SigVOther _ _) = error "We're in the future." -- FIXME
getIssuer i@(Issuer _) = Just i
getIssuer _ = Nothing
eoki = eightOctetKeyID . _tkPKP
hashAlgo (SigV4 _ _ x _ _ _ _) = x
phas (SigV4 _ _ _ xs _ _ _) = colorizePHAs . concatMap (\(SigSubPacket _ (PreferredHashAlgorithms x)) -> x) $ filter isPHA xs
phas _ = Colored Nothing Nothing []
isPHA (SigSubPacket _ (PreferredHashAlgorithms _)) = True
isPHA _ = False
has = map (colorizeHA . hashAlgo) . alleged
colorizeHA ha = uncurry Colored (if ha `elem` [DeprecatedMD5, SHA1] then (Just Red, Just "weak hash algorithm") else (Nothing, Nothing)) ha
isCT (SigSubPacket _ (SigCreationTime _)) = True
isCT _ = False
sigcts (SigV4 _ _ _ xs _ _ _) = map (\(SigSubPacket _ (SigCreationTime x)) -> x) $ filter isCT xs
alleged = filter (\x -> sigissuer x == Just (Issuer (eoki key)))
newest = take 1 . sortBy (comparing (Down . take 1 . sigcts)) -- FIXME: this is terrible
stripOtherSigs tk = tk {
_tkUIDs = map (second alleged) (_tkUIDs tk)
, _tkUAts = map (second alleged) (_tkUAts tk)
}
stripOlderSigs tk = tk {
_tkUIDs = map (second newest) (_tkUIDs tk)
, _tkUAts = map (second newest) (_tkUAts tk)
}
uatspsToString us = "<uat:[" ++ intercalate "," (map uaspToString us) ++ "]>"
uaspToString (ImageAttribute hdr d) = hdrToString hdr ++ ':':show (B.length d) ++ ':':BC8.unpack (Base16.encode (SHA3.hash 48 d))
uaspToString (OtherUASub t d) = "other-" ++ show t ++ ':':show (B.length d) ++ ':':BC8.unpack (Base16.encode (SHA3.hash 48 d))
hdrToString (ImageHV1 JPEG) = "jpeg"
hdrToString (ImageHV1 fmt) = "image-" ++ show (fromFVal fmt)
uidr sps = UIDReport (has sps) (map phas sps) (map (colorizeKETs (fromMaybe 0 mpt) (key^.tkPKP^.timestamp) . getKeyExpirationTimesFromSignature) sps) -- should that be 0?
prettyKeyReport :: POSIXTime -> TK -> Doc
prettyKeyReport cpt key = do
let keyReport = checkKey (Just cpt) key
execWriter $ tell
( linebreak <> text "Key has potential validity:" <+> text (keyStatus keyReport)
<> linebreak <> text "Key has fingerprint:" <+> text (show (keyFingerprint keyReport))
<> linebreak <> text "Checking to see if key is OpenPGPv4:" <+> coloredToColor (text . show) (keyVer keyReport)
<> linebreak <> (\kas -> text "Checking to see if key is RSA or DSA (>= 2048-bit):" <+> coloredToColor (text . show) (pubkeyalgo kas) <+> coloredToColor (text . show) (pubkeysize kas)) (keyAlgorithmAndSize keyReport)
<> linebreak <> text "Checking user-ID- and user-attribute-related items:"
<> mconcat (map (uidtrip (keyCreationTime keyReport)) (unFakeMap (keyUIDsAndUAts keyReport)))
<> linebreak
)
where
coloredToColor f (Colored (Just Green) _ x) = green (f x)
coloredToColor f (Colored (Just Yellow) _ x) = yellow (f x)
coloredToColor f (Colored (Just Red) _ x) = red (f x)
coloredToColor f (Colored Nothing _ x) = f x
uidtrip ts (u, ur) = linebreak <> indent 2 (text u) <> colon
<> linebreak <> indent 4 (text "Self-sig hash algorithms" <> colon <+> (list . map (coloredToColor (text . show)) . uidSelfSigHashAlgorithms) ur)
<> linebreak <> indent 4 (text "Preferred hash algorithms" <> colon <+> mconcat (map ((linebreak <>) . indent 2 . coloredToColor (text . show)) (uidPreferredHashAlgorithms ur)))
<> linebreak <> indent 4 (text "Key expiration times" <> colon <+> mconcat (map ((linebreak <>) . indent 2 . coloredToColor list . fmap (map (text . keyExp ts))) (uidKeyExpirationTimes ur)))
keyExp ts ke = durationPrettyPrinter ke ++ " = " ++ formatTime defaultTimeLocale "%c" (posixSecondsToUTCTime (realToFrac ts + realToFrac ke))
jsonReport :: POSIXTime -> [TK] -> BL.ByteString
jsonReport ps keys = A.encode (map (checkKey (Just ps)) keys)
-- this does not have the same sense of calendar anyone else might
durationPrettyPrinter :: TimeStamp -> String
durationPrettyPrinter = concat . unfoldr durU
where
durU x
| x >= 31557600 = Just ((++"y") . show $ x `div` 31557600, x `mod` 31557600)
| x >= 2629800 = Just ((++"m") . show $ x `div` 2629800, x `mod` 2629800)
| x >= 86400 = Just ((++"d") . show $ x `div` 86400, x `mod` 86400)
| x > 0 = Just ((++"s") . show $ x, 0)
| otherwise = Nothing
data OutputFormat = Pretty | JSON
deriving (Eq, Read, Show)
data Options = Options {
outputFormat :: OutputFormat
}
data Command = Lint Options
lintO :: Parser Options
lintO = Options
<$> option
( long "output-format"
<> metavar "FORMAT"
<> value Pretty
<> showDefault
<> help "output format" )
dispatch :: Command -> IO ()
dispatch (Lint o) = banner' stderr >> hFlush stderr >> doLint o
main :: IO ()
main = do
hSetBuffering stderr LineBuffering
customExecParser (prefs showHelpOnError) (info (helper <*> versioner <*> cmd) (header (banner "hokey") <> progDesc "hOpenPGP Key utility" <> footer (warranty "hokey"))) >>= dispatch
cmd :: Parser Command
cmd = subparser
( command "lint" (info ( Lint <$> lintO) ( progDesc "check key(s) for 'best practices'" )))
doLint :: Options -> IO ()
doLint o = do
cpt <- getPOSIXTime
keys <- runResourceT $ CB.sourceHandle stdin $= conduitGet get $= conduitToTKsDropping $$ CL.consume
output (outputFormat o) cpt keys
where
output Pretty cpt = mapM_ (putDoc . prettyKeyReport cpt)
output JSON cpt = BL.putStr . jsonReport cpt
banner' :: Handle -> IO ()
banner' h = hPutStrLn h (banner "hokey" ++ "\n" ++ warranty "hokey")