-- 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 (pubkeySize, pkalgoAbbrev)
import Codec.Encryption.OpenPGP.Serialize ()
import Codec.Encryption.OpenPGP.Signatures (verifyTKWith, verifySigWith, verifyAgainstKeys)
import Codec.Encryption.OpenPGP.Types
import Control.Applicative ((<$>),(<*>), pure)
import Control.Arrow ((***), second)
import Control.Error.Util (hush)
import Control.Lens ((^.), (&), _1, _2, mapped, over)
import Control.Monad.Trans.Resource (runResourceT)
import Control.Monad.Trans.Writer.Lazy (execWriter, tell)
import qualified Crypto.Hash.SHA3 as SHA3
import qualified Data.Aeson as A
import qualified Data.ByteString as B
import qualified Data.ByteString.Char8 as BC8
import qualified Data.ByteString.Lazy as BL
import qualified Data.ByteString.Base16 as Base16
import Data.Conduit (($=),($$))
import qualified Data.Conduit.Binary as CB
import Data.Conduit.Cereal (conduitGet, conduitPut)
import qualified Data.Conduit.List as CL
import Data.Conduit.OpenPGP.Keyring (conduitToTKsDropping)
import Data.List (unfoldr, elemIndex, findIndex, nub, sort, sortBy, intercalate)
import qualified Data.Map as Map
import Data.Maybe (fromMaybe, mapMaybe, listToMaybe)
import Data.Monoid ((<>), mconcat, Monoid(..))
import Data.Ord (comparing, Down(..))
import Data.Serialize (get, put)
import Data.Text (Text)
import qualified Data.Text as T
import Data.Text.Encoding (decodeUtf8With) -- FIXME: this should be made unnecessary by an API break in hOpenPGP
import Data.Text.Encoding.Error (lenientDecode)
import Data.Time.Clock.POSIX (getPOSIXTime, posixSecondsToUTCTime, POSIXTime)
import Data.Time.Format (formatTime)
import qualified Data.Yaml as Y
import GHC.Generics
import Options.Applicative.Builder (auto, command, footerDoc, headerDoc, helpDoc, 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, stderr, stdin, stdout, hSetBuffering, BufferMode(..))
import System.Locale (defaultTimeLocale)
import Text.PrettyPrint.ANSI.Leijen (colon, green, hardline, hPutDoc, indent, linebreak, list, putDoc, red, text, yellow, (<+>), Doc)
data KAS = KAS {
pubkeyalgo :: Colored PubKeyAlgorithm
, pubkeysize :: Colored (Maybe Int)
, stringrep :: String
} deriving Generic
data Color = Green | Yellow | Red
deriving (Eq, Generic, Ord)
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 (Colored UIDReport)
, keyBestOf :: Maybe UIDReport
} deriving Generic
data UIDReport = UIDReport {
uidSelfSigHashAlgorithms :: [Colored HashAlgorithm]
, uidPreferredHashAlgorithms :: [Colored [HashAlgorithm]]
, uidKeyExpirationTimes :: [Colored [TimeStamp]]
, uidRevocationStatus :: [RevocationStatus]
} deriving Generic
data RevocationStatus = RevocationStatus {
isRevoked :: Bool
, revocationCode :: String
, revocationReason :: Text
} 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
instance A.ToJSON RevocationStatus
instance Monoid UIDReport where
mempty = UIDReport [] [] [] []
mappend (UIDReport a b c d) (UIDReport a' b' c' d') = UIDReport (a++a') (b++b') (c++c') (d <> d')
checkKey :: Maybe POSIXTime -> TK -> KeyReport
checkKey mpt key = (\x -> x { keyBestOf = populateBestOf x }) KeyReport {
keyStatus = either id (const "good") processedTK
, keyFingerprint = key^.tkKey._1 & fingerprint
, keyVer = key^.tkKey._1.keyVersion & colorizeKV
, keyCreationTime = key^.tkKey._1.timestamp
, keyAlgorithmAndSize = KAS {
pubkeyalgo = key^.tkKey._1.pkalgo & colorizePKA
, pubkeysize = key^.tkKey._1.pubkey & colorizePKS . pubkeySize
, stringrep = (key^.tkKey._1.pubkey & either (const "unknown") show . pubkeySize) ++ (key^.tkKey._1.pkalgo & pkalgoAbbrev)
}
, keyUIDsAndUAts = FakeMap (map (\(x,y) -> (x, uidr (Just x) y)) (processedOrOrig^.tkUIDs) ++ map (uatspsToString *** uidr Nothing) (processedOrOrig^.tkUAts))
, keyBestOf = Nothing
}
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) (hush pks)
colorizePKS' (Right 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")
colorizePKS' (Left _) = (Just Red, Just "public key algorithm not understood")
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
eoki pkp
| pkp^.keyVersion == V4 = hush . eightOctetKeyID $ pkp
| pkp^.keyVersion == DeprecatedV3 && elem (pkp^.pkalgo) [RSA,DeprecatedRSASignOnly] = hush . eightOctetKeyID $ pkp
| otherwise = Nothing
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 -> ((==) <$> sigissuer x <*> eoki (key^.tkKey._1)) == Just True)
newest = take 1 . sortBy (comparing (Down . take 1 . sigcts)) -- FIXME: this is terrible
stripOtherSigs tk = tk {
_tkUIDs = map (second alleged) (_tkUIDs tk)
, _tkUAts = map (second alleged) (_tkUAts tk)
}
stripOlderSigs tk = tk {
_tkUIDs = map (second newest) (_tkUIDs tk)
, _tkUAts = map (second newest) (_tkUAts tk)
}
uatspsToString us = "<uat:[" ++ intercalate "," (map uaspToString us) ++ "]>"
uaspToString (ImageAttribute hdr d) = hdrToString hdr ++ ':':show (B.length d) ++ ':':BC8.unpack (Base16.encode (SHA3.hash 48 d))
uaspToString (OtherUASub t d) = "other-" ++ show t ++ ':':show (B.length d) ++ ':':BC8.unpack (Base16.encode (SHA3.hash 48 d))
hdrToString (ImageHV1 JPEG) = "jpeg"
hdrToString (ImageHV1 fmt) = "image-" ++ show (fromFVal fmt)
uidr Nothing sps = Colored Nothing Nothing (UIDReport (has sps) (map phas sps) (map (colorizeKETs (fromMaybe 0 mpt) (key^.tkKey._1.timestamp) . getKeyExpirationTimesFromSignature) sps) (findRevocationReason sps)) -- should that be 0?
uidr (Just u) sps = colorizeUID u (UIDReport (has sps) (map phas sps) (map (colorizeKETs (fromMaybe 0 mpt) (key^.tkKey._1.timestamp) . getKeyExpirationTimesFromSignature) sps) (findRevocationReason sps)) -- should that be 0?
populateBestOf krep = Just (UIDReport <$> best . uidSelfSigHashAlgorithms <*> best . uidPreferredHashAlgorithms <*> best . uidKeyExpirationTimes <*> pure [] $ mconcat (justTheUIDRs krep))
justTheUIDRs = map (decolorize . snd) . unFakeMap . keyUIDsAndUAts
best = take 1 . sortBy (comparing color)
decolorize (Colored _ _ x) = x
colorizeUID u
| '(' `elem` u = Colored (Just Yellow) (Just "parenthesis in uid") -- FIXME: be more discerning
| not ('<' `elem` u) = Colored (Just Yellow) (Just "no left angle bracket in uid") -- FIXME: be more discerning
| otherwise = Colored Nothing Nothing
findRevocationReason = concatMap grabReasons . filter isCertRevocationSig
isCertRevocationSig (SigV4 CertRevocationSig _ _ _ _ _ _) = True
isCertRevocationSig _ = False
grabReasons (SigV4 CertRevocationSig _ _ has _ _ _) = mapMaybe (grabReasons' . _sspPayload) has
grabReasons _ = []
grabReasons' (ReasonForRevocation a b) = Just (RevocationStatus True (show a) (decodeUtf8With lenientDecode b))
grabReasons' _ = Nothing
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 (SpacedFingerprint (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 . maybe "unknown" show) (pubkeysize kas)) (keyAlgorithmAndSize keyReport)
<> linebreak <> text "Checking user-ID- and user-attribute-related items:"
<> mconcat (map (uidtrip (keyCreationTime keyReport) . gottabeabetterway) (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)
| null (uidRevocationStatus ur) = linebreak <> indent 2 (coloredToColor 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)))
| otherwise = linebreak <> indent 2 (coloredToColor text u) <> colon <+> text "[revoked]"
<> linebreak <> indent 4 (text "Revocation code" <> colon <+> list (map (text . revocationCode) (uidRevocationStatus ur)))
<> linebreak <> indent 4 (text "Revocation reason" <> colon <+> list (map (text . T.unpack . revocationReason) (uidRevocationStatus ur)))
keyExp ts ke = durationPrettyPrinter ke ++ " = " ++ formatTime defaultTimeLocale "%c" (posixSecondsToUTCTime (realToFrac ts + realToFrac ke))
gottabeabetterway (a, Colored x y z) = (Colored x y a, z)
jsonReport :: POSIXTime -> TK -> BL.ByteString
jsonReport ps = A.encode . checkKey (Just ps)
yamlReport :: POSIXTime -> TK -> B.ByteString
yamlReport ps = Y.encode . (:[]) . checkKey (Just ps)
-- 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 LintOutputFormat = Pretty | JSON | YAML
deriving (Bounded, Enum, Eq, Read, Show)
data LintOptions = LintOptions {
lintOutputFormat :: LintOutputFormat
}
data Command = CmdLint LintOptions | CmdCanonicalize
lintO :: Parser LintOptions
lintO = LintOptions
<$> option auto
( long "output-format"
<> metavar "FORMAT"
<> value Pretty
<> showDefault
<> ofHelp
)
where
ofHelp = helpDoc . Just $ text "output format" <> hardline <> list (map (text . show) ofchoices)
ofchoices = [minBound..maxBound] :: [LintOutputFormat]
dispatch :: Command -> IO ()
dispatch (CmdLint o) = banner' stderr >> hFlush stderr >> doLint o
dispatch (CmdCanonicalize) = banner' stderr >> hFlush stderr >> doCanonicalize
main :: IO ()
main = do
hSetBuffering stderr LineBuffering
customExecParser (prefs showHelpOnError) (info (helper <*> versioner <*> cmd) (headerDoc (Just (banner "hokey")) <> progDesc "hOpenPGP Key utility" <> footerDoc (Just (warranty "hokey")))) >>= dispatch
cmd :: Parser Command
cmd = subparser
( command "canonicalize" (info ( pure CmdCanonicalize) ( progDesc "arrange key components in a canonical ordering" ))
<> command "lint" (info ( CmdLint <$> lintO) ( progDesc "check key(s) for 'best practices'" ))
)
doLint :: LintOptions -> IO ()
doLint o = do
cpt <- getPOSIXTime
keys <- runResourceT $ CB.sourceHandle stdin $= conduitGet get $= conduitToTKsDropping $$ CL.consume
output (lintOutputFormat o) cpt keys
where
output Pretty cpt = mapM_ (putDoc . prettyKeyReport cpt)
output JSON cpt = mapM_ (BL.putStr . flip BL.append (BL.singleton 0x0a) . jsonReport cpt)
output YAML cpt = mapM_ (B.putStr . yamlReport cpt)
doCanonicalize :: IO ()
doCanonicalize = do
runResourceT $ CB.sourceHandle stdin $= conduitGet get $=
conduitToTKsDropping $= CL.map canonicalize $=
conduitPut put $$ CB.sinkHandle stdout
where
canonicalize (TK k r ui ua s) = TK k
(sort r)
(indepthsort ui)
(indepthsort ua)
(indepthsort s)
indepthsort :: (Ord a, Ord b) => [(a,[b])] -> [(a,[b])]
indepthsort = nub . sort . over (mapped._2) sort
banner' :: Handle -> IO ()
banner' h = hPutDoc h (banner "hokey" <> hardline <> warranty "hokey" <> hardline)
sigissuer :: SignaturePayload -> Maybe EightOctetKeyId
getIssuer :: SigSubPacketPayload -> Maybe EightOctetKeyId
hashAlgo :: SignaturePayload -> HashAlgorithm
sigissuer (SigVOther 2 _) = Nothing
sigissuer (SigV3 {}) = Nothing
sigissuer (SigV4 _ _ _ ys xs _ _) = listToMaybe . mapMaybe (getIssuer . _sspPayload) $ (ys++xs) -- FIXME: what should this be if there are multiple matches?
sigissuer (SigVOther _ _) = error "We're in the future." -- FIXME
getIssuer (Issuer i) = Just i
getIssuer _ = Nothing
hashAlgo (SigV4 _ _ x _ _ _ _) = x
hashAlgo _ = error "V3 sig not supported here"