path: root/lib/KeyRing/BuildKeyDB.hs

{-# LANGUAGE DeriveFunctor            #-}
{-# LANGUAGE DoAndIfThenElse          #-}
{-# LANGUAGE ForeignFunctionInterface #-}
{-# LANGUAGE LambdaCase               #-}
{-# LANGUAGE OverloadedStrings        #-}
{-# LANGUAGE PatternGuards            #-}
{-# LANGUAGE TupleSections            #-}
{-# LANGUAGE ViewPatterns             #-}
module KeyRing.BuildKeyDB where

import           Data.ByteArray.Encoding
import qualified Data.ByteString         as S
import qualified Codec.Encryption.OpenPGP.ASCIIArmor as ASCIIArmor
import           Codec.Encryption.OpenPGP.ASCIIArmor.Types
import           Control.Arrow              (first, second)
import           Control.Exception          (catch)
import           Control.Monad
import           ControlMaybe               (handleIO_)
import           Data.ASN1.BinaryEncoding   (DER (..))
import           Data.ASN1.Encoding         (decodeASN1, encodeASN1)

import           Data.ASN1.Types (ASN1 (End, IntVal, Start), ASN1ConstructionType (Sequence), ASN1Object, fromASN1, toASN1)


import           Data.Binary
import           Data.Bits                  (testBit)
import           Data.ByteString.Lazy       (ByteString)
import qualified Data.ByteString.Lazy       as L (ByteString, concat, empty,
                                                  hGetContents,
                                                  null, toChunks,
                                                  toStrict, head)
import           Data.Char
import           Data.List
import qualified Data.Map                   as Map
import           Data.Maybe
import           Data.OpenPGP
import           Data.OpenPGP.Util          (GenerateKeyParams (..), fingerprint, generateKey, pgpSign, verify)


import           Data.Time.Clock            (UTCTime)
import           Data.Time.Clock.POSIX      (utcTimeToPOSIXSeconds)
import           System.Directory           (doesFileExist)

import           System.IO.Error            (isDoesNotExistError)
import qualified Crypto.PubKey.ECC.Types    as ECC
import qualified Codec.Compression.GZip     as GZip
import qualified Crypto.PubKey.RSA          as RSA
import qualified Data.X509                  as X509
import           System.Posix.Files         (getFdStatus, getFileStatus,
                                             modificationTime)


import qualified System.Posix.Types         as Posix
import           Data.Hourglass
import           Foreign.C.Types            (CTime (..))
import           Data.Traversable           (sequenceA)
import           System.IO                  (openFile, IOMode(ReadMode))

import           System.Posix.IO            (fdToHandle)
import           Compat                     ()
import qualified Data.ByteString.Lazy.Char8 as Char8
import           Network.Socket

import           Base58
import qualified CryptoCoins
import           FunctorToMaybe
import qualified Hosts
import           PEM
import           ScanningParser
import           TimeUtil

import           KeyRing.Types
import           KeyDB
import           Transforms
import           PacketTranscoder
import           GnuPGAgent
import           ByteStringUtil
import           Text.XXD

newtype IPsToWriteToHostsFile = IPsToWriteToHostsFile [SockAddr]
-- | buildKeyDB
--
--   merge all keyrings, PEM files, and wallets into process memory.
--
buildKeyDB :: InputFileContext -> Maybe String -> KeyRingOperation
              -> IO (KikiCondition (({- db        -} KeyDB
                                    ,{- grip      -} Maybe String
                                    ,{- wk        -} Maybe MappedPacket
                                    ,{- hs        -} ({- hostdbs0 -}[Hosts.Hosts],
                                                      {- hostdbs  -}[Hosts.Hosts],
                                                      {- u1       -}Hosts.Hosts,
                                                      {- gpgnames -}[Hostnames],
                                                      {- outgoing_names -}IPsToWriteToHostsFile)
                                    ,{- accs      -} Map.Map InputFile Access
                                    ,{- transcode -} PacketTranscoder
                                    ,{- unspilled -} Map.Map InputFile Message
                                    )
                                   ,{- report_imports -} [(FilePath,KikiReportAction)]))
buildKeyDB ctx grip0 keyring = do
    let files istyp = do
            (f,stream) <- Map.toList (opFiles keyring)
            guard (istyp $ typ stream)
            return f -- resolveInputFile ctx f

        ringMap0 = Map.filter (isring . typ) $ opFiles keyring
        (genMap,ringMap) = Map.partitionWithKey isgen ringMap0
            where
                isgen (Generate _ _) _ = True
                isgen _              _ = False

        readp :: InputFile -> StreamInfo -> IO (StreamInfo, Message)
        readp f stream = fmap readp0 $ readPacketsFromFile ctx f
         where
          readp0 (codec,ps) = (stream { access = acc', typ = PGPPackets codec }, ps)
           where acc' = case access stream of
                            AutoAccess ->
                                case ps of
                                    Message ((PublicKeyPacket {}):_) -> Pub
                                    Message ((SecretKeyPacket {}):_) -> Sec
                                    _                                -> AutoAccess
                            acc -> acc

        readw wk n = fmap (n,) (readPacketsFromWallet wk n)

    -- KeyRings (todo: KikiCondition reporting?)
    (spilled,mwk,grip,accs,keyqs,unspilled) <- do
        ringPackets <- Map.traverseWithKey readp ringMap
        let _ = ringPackets :: Map.Map InputFile (StreamInfo, Message)

        let grip = grip0 `mplus` (show . fingerprint <$> fstkey)
              where
                fstkey = do
                    (_,Message ps) <- Map.lookup HomeSec ringPackets
                    listToMaybe ps

            -- | spilled
            --    ring packets with info available for export
            -- | unspilled
            --    the rest
            (spilled,unspilled) = Map.partition (spillable . fst) ringPackets

            -- | keys
            -- process ringPackets, and get a map of fingerprint info to
            -- to a packet, remembering it's original file, access.
            keys :: Map.Map KeyKey (OriginMapped Query)
            mwk :: Maybe MappedPacket
            (mwk, keys) = keyQueries grip ringPackets

            -- | accs
            -- file access(Sec | Pub) lookup table
            accs :: Map.Map InputFile Access
            accs = fmap (access . fst) ringPackets
        return (spilled,mwk,grip,accs,keys,fmap snd unspilled)

    transcode <- makeMemoizingDecrypter (opPassphrases keyring) ctx (mwk,keyqs)
    let doDecrypt = transcode (Unencrypted,S2K 100 "")

    let wk = fmap packet mwk
        rt0 = KeyRingRuntime { rtPubring     = homepubPath ctx
                             , rtSecring     = homesecPath ctx
                             , rtGrip        = grip
                             , rtWorkingKey  = wk
                             , rtRingAccess  = accs
                             , rtKeyDB       = emptyKeyDB
                             , rtPassphrases = transcode
                             }
    -- autosigns and deletes
    transformed0 <-
        let trans :: InputFile -> (StreamInfo,Message) -> IO (KikiCondition (KikiReport,KeyDB))
            trans f (info,ps) = do
                let manip = combineTransforms (transforms info)
                    rt1 = rt0 { rtKeyDB = merge emptyKeyDB f ps }
                    acc = Just Sec /= Map.lookup f accs
                r <- performManipulations doDecrypt rt1 mwk manip
                try r $ \(rt2,report) -> do
                return $ KikiSuccess (report,rtKeyDB rt2)
        -- XXX: Unspilled keys are not obtainable from rtKeyDB.
        --  If the working key is marked non spillable, then how
        --  would we look up it's UID and such?
        in fmap sequenceA $ Map.traverseWithKey trans spilled
    try transformed0 $ \transformed -> do
    let -- | db_rings - all keyrings combined into one
        db_rings = Map.foldlWithKey' mergeIt emptyKeyDB transformed
                    where
                      mergeIt db f (_,dbtrans)
                        = mergeKeyDB mergeKeyData db dbtrans
        -- | reportTrans
        -- events, indexed by file
        reportTrans :: [(FilePath, KikiReportAction)]
        reportTrans = concat $ Map.elems $ fmap fst transformed

    -- Wallets
    let importWalletKey wk db' (top,fname,sub,tag) = do
            try db' $ \(db',report0) -> do
            r <- doImportG transcode
                      db'
                      (fmap keykey $ maybeToList wk)
                      [mkUsage tag]
                      fname
                      sub
            try r $ \(db'',report) -> do
            return $ KikiSuccess (db'', report0 ++ report)

    wms <- mapM (readw wk) (files iswallet)
    let wallet_keys = do
            maybeToList wk
            (fname,xs) <- wms
            (_,sub,(_,m)) <- xs
            (tag,top) <- Map.toList m
            return (top,fname,sub,tag)

    db <- foldM (importWalletKey wk) (KikiSuccess (db_rings,[])) wallet_keys
    try db $ \(db,reportWallets) -> do

    -- PEM files
    let pems = do
            (n,stream) <- Map.toList $ opFiles keyring
            grip <- maybeToList grip
            guard $ spillable stream && isSecretKeyFile (typ stream)
            let us = mapMaybe usageFromFilter [fill stream,spill stream]
            usage <- take 1 us
            guard $ all (==usage) $ drop 1 us
            -- TODO: KikiCondition reporting for spill/fill usage mismatch?
            -- TODO: parseSpec3
            let (topspec,subspec) = parseSpec grip usage
                ms = map fst $ filterMatches topspec (kkData db)
                cmd = initializer stream
            return (n,subspec,ms,stream, cmd)

    imports <- filterM (\case (ArgFile n,_,_,_,_) -> doesFileExist n
                              _                   -> return True)
                       pems
    db <- foldM (importSecretKey transcode) (KikiSuccess (db,[])) imports
    try db $ \(db,reportPEMs) -> do

    -- generate keys
    let gens = mapMaybe g $ Map.toList genMap
                where g (Generate _ params,v) = Just (params,v)
                      g _                     = Nothing

    db <- generateInternals transcode mwk db gens
    try db $ \(db,reportGens) -> do

    r <- mergeHostFiles keyring db ctx
    try r $ \((db,hs),reportHosts) -> do

    return $ KikiSuccess ( (db, grip, mwk, hs, accs, transcode, unspilled)
                         , reportTrans ++ reportWallets ++ reportPEMs ++ reportGens ++ reportHosts )


isring :: FileType -> Bool
isring (PGPPackets {}) = True
isring _               = False

decodePacketList :: L.ByteString -> [Packet]
decodePacketList some =
          case decodeOrFail some of
            Right (more,_,msg ) -> msg : decodePacketList more
            Left  (_,_,_)       -> []

readPacketsFromFile :: InputFileContext -> InputFile -> IO (PacketsCodec, Message)
readPacketsFromFile ctx fname = do
    input <- readInputFileL ctx fname
    let tryBinary = case decodeOrFail input of
          Right (more,_,pkt) -> (,) BinaryPackets $ Message $ pkt : decodePacketList more
          Left  (_,_,_)      -> tryAscii
        tryAscii = case ASCIIArmor.decodeLazy input of
          Right (Armor pubOrSec headers bs:_) -> (,) AsciiArmor $ Message $ decodePacketList bs
          _                                   -> (,) DetectAscii $ Message []
    return $ if L.null input || testBit (L.head input) 7
                then tryBinary
                else tryAscii

readPacketsFromWallet ::
    Maybe Packet
    -> InputFile
    -> IO [(Packet,Packet,(Packet,Map.Map FilePath Packet))]
readPacketsFromWallet wk fname = do
    let ctx = InputFileContext "" ""
    timestamp <- getInputFileTime ctx fname
    input <- readInputFileL ctx fname
    let (ks,_) = slurpWIPKeys timestamp input
    {-
    unless (null ks) $ do
        -- decrypt wk
        -- create sigs
        -- return key/sig pairs
        return () -}
    return $ do
        wk <- maybeToList wk
        guard (not $ null ks)
        let prep (tagbyte,k) = (wk,k,(k,Map.singleton tag wk))
                                where tag = CryptoCoins.nameFromSecretByte tagbyte
        (wk,MarkerPacket,(MarkerPacket,Map.empty))
         :map prep ks

spillable :: StreamInfo -> Bool
spillable (spill -> KF_None) = False
spillable _                  = True


-- | combineTransforms
-- remove redundant transforms, and compile the rest to PacketUpdate(s)
--
-- equivalent to:
-- > combineTransforms = group (sort trans) >>= take 1 >>= resolveTransform t rt kd
combineTransforms :: [Transform] -> KeyRingRuntime -> KeyData -> [PacketUpdate]
combineTransforms trans rt kd = updates
 where
    updates = -- kManip operation rt kd ++
              concatMap (\t -> resolveTransform t rt kd) sanitized
    sanitized = group (sort trans) >>= take 1

merge :: KeyDB -> InputFile -> Message -> KeyDB
merge db inputfile (Message ps) = merge_ db filename qs
 where
    filename = resolveForReport Nothing inputfile
    qs = scanPackets filename ps

-- Aggregate packets into a list of triples:
--
--   A top (master) key
--
--   A subkey, or if this entry corresponds to the master-key, this field is a
--   MarkerPacket placeholder.
--
--   An optional trust packet in the form of a singleton or empty Map whose key
--   is the filename.
scanPackets :: FilePath -> [Packet] -> [(Packet,Packet,(Packet,Map.Map FilePath Packet))]
scanPackets filename [] = []
scanPackets filename (p:ps) = scanl doit (doit (MarkerPacket,MarkerPacket,ret MarkerPacket) p) ps
 where
    ret p = (p,Map.empty)
    doit (top,sub,prev) p =
        case p of
            _ | isKey p && not (is_subkey p) -> (p,MarkerPacket,ret p)
            _ | isKey p && is_subkey p       -> (top,p,ret p)
            _ | isJust (isUserID p)          -> (top,p,ret p)
            _ | isTrust p                    -> (top,sub,updateTrust top sub prev p)
            _                                -> (top,sub,ret p)

    -- Most arguments are ignored and we simply create the singleton trust-map when appropriate.
    -- XXX: Simplify this?
    updateTrust top (PublicKeyPacket {}) (pre,t) p = (pre,Map.insert filename p t) -- public
    updateTrust (PublicKeyPacket {}) _   (pre,t) p = (pre,Map.insert filename p t) -- public
    updateTrust _                    _   (pre,t) p = (pre,Map.insert filename p t) -- secret


mergeKeyData :: KeyData -> KeyData -> KeyData
mergeKeyData (KeyData atop asigs auids asubs)
             (KeyData btop  bsigs buids bsubs)
    = KeyData top sigs uids subs
 where
    mergeMapped a b =
        MappedPacket { packet = packet a
                     , locations = Map.union (locations a) (locations b)
                     }

    top = mergeMapped atop btop

    sigs = foldl' (flip mergeSig) asigs bsigs

    uids = Map.unionWith mergeUIDSigs auids buids
    subs = Map.unionWith mergeSub asubs bsubs

    mergeSub :: SubKey -> SubKey -> SubKey
    mergeSub (SubKey a as) (SubKey b bs) =
        SubKey (mergeMapped a b)
               (foldl' (flip mergeSig) as bs)

    mergeUIDSigs :: ([SigAndTrust],OriginMap) -> ([SigAndTrust],OriginMap)
                    -> ([SigAndTrust],OriginMap)
    mergeUIDSigs (as,am) (bs,bm) = (foldl' (flip mergeSig) as bs, Map.union am bm)

doImportG
  :: PacketTranscoder
     -> KeyDB
     -> [KeyKey] -- m0,  only head is used
     -> [SignatureSubpacket] -- tags
     -> InputFile
     -> Packet
     -> IO (KikiCondition (KeyDB, [(FilePath,KikiReportAction)]))
doImportG transcode db m0 tags fname key = do
    let kk = head m0
    {-
    let Just kd@(KeyData top topsigs uids subs) = Map.lookup kk (byKeyKey db)
    kdr <- insertSubkey transcode kk kd tags fname key
    try kdr $ \(kd',rrs) -> return $ KikiSuccess ( alterKeyDB (const $ Just kd') kk db
                                                 , rrs )
    -}
    let go (Just kd@(KeyData top topsigs uids subs)) = insertSubkey transcode kk kd tags fname key
    transmuteAt go kk db


iswallet :: FileType -> Bool
iswallet (WalletFile {}) = True
iswallet _               = False

isSecretKeyFile :: FileType -> Bool
isSecretKeyFile PEMFile         = True
isSecretKeyFile DNSPresentation = True
isSecretKeyFile _               = False

usageFromFilter :: MonadPlus m => KeyFilter -> m String
usageFromFilter (KF_Match usage) = return usage
usageFromFilter _                = mzero

-- | Parse a key specification.
-- The first argument is a grip for the default working key.
parseSpec :: String -> String -> (KeySpec,Maybe String)
parseSpec wkgrip spec =
    if not slashed
        then
            case prespec of
                AnyMatch                               -> (KeyGrip "", Nothing)
                EmptyMatch                             -> error "Bad key spec."
                WorkingKeyMatch                        -> (KeyGrip wkgrip, Nothing)
                SubstringMatch (Just KeyTypeField) tag -> (KeyGrip wkgrip, Just tag)
                SubstringMatch Nothing str             -> (KeyGrip wkgrip, Just str)
                SubstringMatch (Just UserIDField) ustr -> (KeyUidMatch ustr, Nothing)
                FingerprintMatch fp                    -> (KeyGrip fp, Nothing)
        else
            case (prespec,postspec) of
                (FingerprintMatch fp, SubstringMatch st t)
                    | st /= Just UserIDField                -> (KeyGrip fp, Just t)
                (SubstringMatch mt u, _)
                    | postspec `elem` [AnyMatch,EmptyMatch]
                      && mt /= Just KeyTypeField            -> (KeyUidMatch u, Nothing)
                (SubstringMatch mt u, SubstringMatch st t)
                    | mt /= Just KeyTypeField
                      && st /= Just UserIDField             -> (KeyUidMatch u, Just t)
                (FingerprintMatch _,FingerprintMatch _) -> error "todo: support fp:/fp: spec"
                (_,FingerprintMatch fp)                 -> error "todo: support /fp: spec"
                (FingerprintMatch fp,_)                 -> error "todo: support fp:/ spec"
                _                                       -> error "Bad key spec."
 where
    (preslash,slashon) = break (=='/') spec
    slashed = not $ null $ take 1 slashon
    postslash = drop 1 slashon

    prespec = parseSingleSpec preslash
    postspec = parseSingleSpec postslash

{-
 - BUGGY
parseSpec grip spec = (topspec,subspec)
 where
     (topspec0,subspec0) = unprefix '/' spec
     (toptyp,top) = unprefix ':' topspec0
     (subtyp,sub) = unprefix ':' subspec0
     topspec = case () of
                    _ | null top && or [ subtyp=="fp"
                                       , null subtyp && is40digitHex sub
                                       ]
                                 -> KeyGrip sub
                    _ | null top && null grip -> KeyUidMatch sub
                    _ | null top -> KeyGrip grip
                    _ | toptyp=="fp" || (null toptyp && is40digitHex top)
                                 -> KeyGrip top
                    _ | toptyp=="u" -> KeyUidMatch top
                    _            -> KeyUidMatch top
     subspec = case subtyp of
                "t" -> Just sub
                "fp" | top=="" -> Nothing
                "" | top=="" && is40digitHex sub -> Nothing
                "" -> listToMaybe sub >> Just sub
                _ -> Nothing

     is40digitHex xs = ys == xs && length ys==40
      where
        ys = filter ishex xs
        ishex c | '0' <= c && c <= '9' = True
                | 'A' <= c && c <= 'F' = True
                | 'a' <= c && c <= 'f' = True
        ishex c = False

     -- | Split a string into two at the first occurance of the given
     -- delimiter.  If the delimeter does not occur, then the first
     -- item of the returned pair is empty and the second item is the
     -- input string.
     unprefix c spec = if null (snd p) then swap p else (fst p, tail (snd p))
      where p = break (==c) spec
-}
outgoing_names :: KeyDB -> [Hosts.Hosts] -> IPsToWriteToHostsFile
outgoing_names db hostdbs0 = IPsToWriteToHostsFile $ do
    Hostnames addr _ gns _ <- gpgnames
    guard . not $ null gns
    guard $ all (null . Hosts.namesForAddress addr) hostdbs0
    return addr
  where
    gpgnames = map getHostnames $ keyData db

filterMatches :: KeySpec -> [(KeyKey,KeyData)] -> [(KeyKey,KeyData)]
filterMatches spec ks = filter (matchSpec spec . snd) ks

importSecretKey ::
  (PacketTranscoder)
  -> KikiCondition
       (KeyDB, [(FilePath, KikiReportAction)])
  -> (InputFile, Maybe [Char], [KeyKey], StreamInfo, t)
  -> IO (KikiCondition (KeyDB, [(FilePath, KikiReportAction)]))
importSecretKey transcode db' tup = do
            try db' $ \(db',report0) -> do
            r <- doImport transcode
                      db'
                      tup
            try r $ \(db'',report) -> do
            return $ KikiSuccess (db'', report0 ++ report)

generateInternals ::
    PacketTranscoder
    -> Maybe MappedPacket
    -> KeyDB
    -> [(GenerateKeyParams,StreamInfo)]
    -> IO (KikiCondition (KeyDB, [(FilePath, KikiReportAction)]))
generateInternals transcode mwk db gens = do
    case mwk of
        Nothing -> return $ KikiSuccess (db,[])
        Just mpkt -> do
            let kk = keykey (packet mpkt)
            transmuteAt (go kk) kk db
        where
         go kk (Just kd0) = foldM (generateSubkey transcode) (KikiSuccess (kd0,[])) gens

mergeHostFiles :: KeyRingOperation -> KeyDB -> InputFileContext
     -> IO
          (KikiCondition
             ( ( KeyDB
               , ( [Hosts.Hosts]
                 , [Hosts.Hosts]
                 , Hosts.Hosts
                 , [Hostnames]
                 , IPsToWriteToHostsFile))
             , [(FilePath,KikiReportAction)]))
mergeHostFiles krd db ctx = do
    let hns = files ishosts
        ishosts Hosts = True
        ishosts _     = False
        files istyp = do
            (f,stream) <- Map.toList (opFiles krd)
            guard (istyp $ typ stream)
            return f

        readInputFileL' ctx f =
            readInputFileL ctx f
                `catch` \e -> do when (not $ isDoesNotExistError e) $ do
                                   return () -- todo report problem
                                 return L.empty

    hostdbs0 <- mapM (fmap Hosts.decode . readInputFileL' ctx) hns

    let gpgnames = map getHostnames $ keyData db
        os = do
            Hostnames addr ns _ _ <- gpgnames
            n <- ns
            return (addr,n)
        setOnions hosts = foldl' (flip $ uncurry Hosts.assignName) hosts os
        -- we ensure .onion names are set properly
        hostdbs = map setOnions hostdbs0
        addrs = outgoing_names db hostdbs0
    -- putStrLn $ "hostdbs = " ++ show hostdbs

    -- 1. let U = union all the host dbs
    --     preserving whitespace and comments of the first
    let u0 = foldl' Hosts.plus Hosts.empty hostdbs
        -- we filter U to be only finger-dresses
        u1 = Hosts.filterAddrs (hasFingerDress db) u0

    -- let nf h = map Char8.unpack $ Hosts.namesForAddress (fromJust $ Hosts.inet_pton "fdf4:ed98:29c7:6226:9bde:a5b4:d564:3321") h
    {-
    putStrLn $ "_  = {\n" ++ show (head hostdbs) ++ "}"
    putStrLn $ "--> " ++ show (nf (head hostdbs))
    putStrLn $ "u0 = {\n" ++ show u0 ++ "}"
    putStrLn $ "--> " ++ show (nf u0)
    putStrLn $ "u1 = {\n" ++ show u1 ++ "}"
    putStrLn $ "--> " ++ show (nf u1)
    -}

    -- 2. replace gpg annotations with those in U
    -- forM use_db
    db' <- mapKeyDB (setHostnames addrs u1) db

    return $ KikiSuccess ((db',(hostdbs0,hostdbs,u1,gpgnames,addrs)),[])

readInputFileL :: InputFileContext -> InputFile -> IO L.ByteString
readInputFileL ctx (Pipe fd _)   = fdToHandle fd >>= L.hGetContents
readInputFileL ctx (FileDesc fd) = fdToHandle fd >>= L.hGetContents
readInputFileL ctx inp = do
    let fname = resolveInputFile ctx inp
    hs <- mapM (`openFile` ReadMode) fname
    fmap L.concat $ mapM (hGetContentsN oneMeg) hs

getInputFileTime :: InputFileContext -> InputFile -> IO CTime
getInputFileTime ctx (Pipe fdr fdw) = do
    mt <- handleIO_ (return Nothing) $ Just <$> modificationTime <$> getFdStatus fdr
    maybe tryw return mt
 where
    tryw = do
        handleIO_ (error $ (resolveForReport Nothing $ Pipe fdr fdw) ++": modificaiton time?")
            $ modificationTime <$> getFdStatus fdw
getInputFileTime ctx (FileDesc fd) = do
    handleIO_ (error $ "&"++show fd++": modificaiton time?") $
                    modificationTime <$> getFdStatus fd
getInputFileTime ctx (resolveInputFile ctx -> [fname]) = do
    handleIO_ (error $ fname++": modificaiton time?") $
                    modificationTime <$> getFileStatus fname

slurpWIPKeys :: Posix.EpochTime -> L.ByteString -> ( [(Word8,Packet)], [L.ByteString])
slurpWIPKeys stamp "" = ([],[])
slurpWIPKeys stamp cs =
    let (b58,xs) = Char8.span (`elem` base58chars) cs
        mb        = decode_btc_key stamp (Char8.unpack b58)
    in if L.null b58
        then let (ys,xs') = Char8.break (`elem` base58chars) cs
                 (ks,js)  = slurpWIPKeys stamp xs'
             in (ks,ys:js)
        else let (ks,js) = slurpWIPKeys stamp xs
             in maybe (ks,b58:js) (\(net,Message [k])->((net,k):ks,js)) mb

merge_ :: KeyDB -> FilePath -> [(Packet,Packet,(Packet,Map.Map FilePath Packet))]
                -> KeyDB
merge_ db filename qs = foldl mergeit db (zip [0..] qs)
 where
    -- mergeit db (_,_,TrustPacket {}) = db -- Filter TrustPackets
    mergeit :: KeyDB -> (Int,(Packet,Packet,(Packet,Map.Map FilePath Packet))) -> KeyDB
    mergeit db adding@(n,(top,sub,ptt@(p,trustmap)))
        | isKey top = alterKeyDB update (keykey top) db
      where
        update Nothing   = Just $ KeyData (mappedPacketWithHint filename p n) [] Map.empty Map.empty
        update (Just kd) = dbInsertPacket kd filename adding
    mergeit _  (_,(_,_,(UnsupportedPacket tag bytes,_)))
                           = error $ unlines $ ("Unsupported packet type "++show tag) : xxd 0 (L.toStrict bytes)
    mergeit _  (_,(_,_,p)) = error $ "Unexpected PGP packet 3: "++whatP p

    whatP (a,_) = concat . take 1 . words . show $ a


insertSubkey :: PacketTranscoder
                      -> keykey
                      -> KeyData
                      -> [SignatureSubpacket]
                      -> InputFile
                      -> Packet
                      -> IO (KikiCondition (KeyData, [(FilePath, KikiReportAction)]))
insertSubkey transcode kk (KeyData top topsigs uids subs) tags inputfile key0 = do
    let topcipher = symmetric_algorithm $ packet top
        tops2k    = s2k $ packet top
        doDecrypt = transcode (Unencrypted,S2K 100 "")
        fname = resolveForReport Nothing inputfile
        subkk = keykey key0
        istor = do
            guard ("tor" `elem` mapMaybe usage tags)
            return $ torUIDFromKey key0
        addOrigin (SubKey mp sigs) =
                                    let mp' = mp
                                          { locations = Map.insert fname
                                                             (origin (packet mp) (-1))
                                                             (locations mp) }
                                    in SubKey mp' sigs

    subkey_result <- do
        case Map.lookup subkk subs of
            Just sub -> return $ KikiSuccess (False,addOrigin sub,Nothing)
            Nothing  -> do
                wkun' <- doDecrypt top
                try wkun' $ \wkun -> do
                key' <- transcode (topcipher,tops2k) $ mappedPacket "" key0
                try key' $ \key -> do
                return $ KikiSuccess (True, SubKey (mappedPacket fname key) [], Just (wkun,key))


    try subkey_result $ \(is_new,subkey,decrypted) -> do

    let subs' = Map.insert subkk subkey subs

    uids' <- flip (maybe $ return $ KikiSuccess (uids,[])) istor $ \idstr -> do
                let has_torid = do
                     -- TODO: check for omitted real name field
                     (sigtrusts,om) <- Map.lookup (UidString idstr) uids
                     listToMaybe $ do
                         s <- (signatures $ Message (packet top:UserIDPacket idstr:map (packet . fst) sigtrusts))
                         signatures_over $ verify (Message [packet top]) s
                flip (flip maybe $ const $ return $ KikiSuccess (uids,[])) has_torid $ do

                let keyflags = keyFlags (error "dummy argument (insertSubkey)") (map packet $ flattenAllUids fname True uids)
                    uid = UserIDPacket idstr
                    -- sig_ov = fst $ torsig g (packet top) wkun uid timestamp keyflags
                    tor_ov = makeInducerSig (packet top) (packet top) uid keyflags
                wkun' <- maybe (doDecrypt top) (return . KikiSuccess . fst) decrypted
                try wkun' $ \wkun -> do
                sig_ov <- pgpSign (Message [wkun])
                                  tor_ov
                                  SHA1
                                  (show $ fingerprint wkun)
                flip (maybe $ return $ KikiSuccess (uids,[(fname, WarnFailedToMakeSignature)]))
                     (sig_ov >>= listToMaybe . signatures_over)
                     $ \sig -> do
                let om = Map.singleton fname (origin sig (-1))
                    trust = Map.empty
                return $ KikiSuccess
                    ( Map.insert (UidString idstr) ([( (mappedPacket fname sig) {locations=om}
                                         , trust)],om) uids
                    , [] )

    try uids' $ \(uids',report) -> do

    let SubKey subkey_p subsigs = subkey
        wk = packet top
        (xs',minsig,ys') = findTag tags wk key0 subsigs
        doInsert mbsig = do
            -- NEW SUBKEY BINDING SIGNATURE
            -- XXX: Here I assume that key0 is the unencrypted version
            --      of subkey_p.  TODO: Check this assumption.
            sig' <- makeSig doDecrypt top fname subkey_p{packet=key0} tags mbsig
            try sig' $ \(sig',report) -> do
            report <- return $ fmap (fname,) report ++ [(fname, YieldSignature)]
            let subs' = Map.insert subkk
                                   (SubKey subkey_p $ xs'++[sig']++ys')
                                   subs
            return $ KikiSuccess ( KeyData top topsigs uids' subs'
                                 , report )

    report <- let f = if is_new then (++[(fname,YieldSecretKeyPacket s)])
                                    else id
                  s = show (fmap fst minsig,fingerprint key0)
              in return (f report)

    case minsig of
        Nothing          -> doInsert Nothing -- we need to create a new sig
        Just (True,sig)  -> -- we can deduce is_new == False
                            -- we may need to add a tor id
                            return $ KikiSuccess ( KeyData top topsigs uids' subs'
                                                 , report )
        Just (False,sig) -> doInsert (Just sig) -- We have a sig, but is missing usage@ tag


mergeSig :: SigAndTrust -> [SigAndTrust] -> [SigAndTrust]
mergeSig sig sigs =
      let (xs,ys) = break (isSameSig (first packet sig)) sigs
      in if null ys
          then sigs++[sig] -- [first (flip (mappedPacketWithHint fname) n) sig]
          else let y:ys'=ys
               in xs ++ (mergeSameSig sig y : ys')
     where
        isSameSig (a,_) (MappedPacket {packet=b},_) | isSignaturePacket a && isSignaturePacket b =
            a { unhashed_subpackets=[] } == b { unhashed_subpackets = [] }
        isSameSig (a,_) (MappedPacket {packet=b},_) = a==b

        mergeSameSig :: (MappedPacket,TrustMap) -> (MappedPacket,TrustMap) -> (MappedPacket, TrustMap)
        mergeSameSig (a,ta) (m@(MappedPacket{packet=b,locations=locs}),tb)
          | isSignaturePacket (packet a) && isSignaturePacket b =
                ( m { packet = b { unhashed_subpackets =
                                      union (unhashed_subpackets b) (unhashed_subpackets $ packet a)
                                 }
                   , locations = Map.union (locations a) locs } -- Map.insert fname (origin a n) locs }
                -- TODO: when merging items, we should delete invalidated origins
                -- from the orgin map.
                , tb `Map.union` ta )

        mergeSameSig a b = b -- trace ("discarding dup "++show a) b

parseSingleSpec :: String -> SingleKeySpec
parseSingleSpec "*"              = AnyMatch
parseSingleSpec "-"              = WorkingKeyMatch
parseSingleSpec ""               = EmptyMatch
parseSingleSpec ('t':':':tag)    = SubstringMatch (Just KeyTypeField) tag
parseSingleSpec ('u':':':tag)    = SubstringMatch (Just UserIDField) tag
parseSingleSpec ('c':':':tag)    = SubstringMatch (Just GroupIDField) tag
parseSingleSpec ('f':'p':':':fp) = FingerprintMatch fp
parseSingleSpec str
    | is40digitHex str = FingerprintMatch str
    | otherwise        = SubstringMatch Nothing str

is40digitHex :: [Char] -> Bool
is40digitHex xs = ys == xs && length ys==40
      where
        ys = filter ishex xs
        ishex c | '0' <= c && c <= '9' = True
                | 'A' <= c && c <= 'F' = True
                | 'a' <= c && c <= 'f' = True
        ishex c = False

matchSpec :: KeySpec -> KeyData -> Bool
matchSpec (KeyGrip grip) (KeyData p _ _ _)
    | matchpr grip (packet p)==grip = True
    | otherwise                     = False

matchSpec (KeyTag key tag) (KeyData _ sigs _ _) = not . null $ filter match ps
 where
    ps = map (packet .fst) sigs
    match p = isSignaturePacket p
                && has_tag tag p
                && has_issuer key p
    has_issuer key p = isJust $ do
        issuer <- signature_issuer p
        guard $ matchpr issuer key == issuer
    has_tag tag p = tag `elem` mapMaybe usage (hashed_subpackets p)
                    || tag `elem` map usageString (mapMaybe keyflags (hashed_subpackets p))

matchSpec (KeyUidMatch pat) (KeyData _ _ uids _) = not $ null us
  where
    us = filter (isInfixOf pat) $ unUidString <$> Map.keys uids

doImport
  :: PacketTranscoder
     -> KeyDB
     -> (InputFile, Maybe [Char], [KeyKey], StreamInfo, t)
     -> IO (KikiCondition (KeyDB, [(FilePath,KikiReportAction)]))
doImport transcode db (fname,subspec,ms,typ -> typ,_) = do
    flip (maybe $ return CannotImportMasterKey)
         subspec $ \tag -> do
    (certs,keys) <- case typ of
        PEMFile -> do
            ps <- readSecretPEMFile fname
            let (mapMaybe spemCert -> certs,mapMaybe spemPacket-> keys)
                    = partition (isJust . spemCert) ps
            return (certs,keys)
        DNSPresentation -> do
            p <- readSecretDNSFile fname
            return ([],[p])
    -- TODO Probably we need to move to a new design where signature
    -- packets are merged into the database in one phase with null
    -- signatures, and then the signatures are made in the next phase.
    -- This would let us merge annotations (like certificates) from
    -- seperate files.
    foldM (importKey tag certs) (KikiSuccess (db,[])) keys
 where
    importKey tag certs prior key = do
        try prior $ \(db,report) -> do
        let (m0,tailms) = splitAt 1 ms
        if (not (null tailms) || null m0)
            then return $ AmbiguousKeySpec (resolveForReport Nothing fname)
            else do
                let kk = keykey key
                    cs = filter (\c -> kk==keykey (pcertKey c)) certs
                    blobs = map mkCertNotation $ nub $ map pcertBlob cs
                    mkCertNotation bs = NotationDataPacket
                        { human_readable = False
                        , notation_name = "x509cert@"
                        , notation_value = Char8.unpack bs }
                    datedKey = key { timestamp = fromTime $ minimum dates }
                    dates = fromTime (timestamp key) : map pcertTimestamp certs
                r <- doImportG transcode db m0 (mkUsage tag:blobs) fname datedKey
                try r $ \(db',report') -> do
                return $ KikiSuccess (db',report++report')

generateSubkey ::
  PacketTranscoder
  -> KikiCondition (KeyData, [(FilePath, KikiReportAction)]) -- db
  -> (GenerateKeyParams, StreamInfo)
  -> IO (KikiCondition (KeyData, [(FilePath, KikiReportAction)]))
generateSubkey transcode kd' (genparam,StreamInfo { spill = KF_Match tag }) = do
    try kd' $ \(kd,report0) -> do
    let subs = do
            SubKey p sigs <- Map.elems $ keySubKeys kd
            filter (has_tag tag) $ map (packet . fst) sigs
    if null subs
      then do
        newkey <- generateKey genparam
        kdr <- insertSubkey transcode (keykey (keyPacket kd)) kd [mkUsage tag] (ArgFile "") newkey
        try kdr $ \(newkd,report) -> do
        return $ KikiSuccess (newkd, report ++ [("", NewPacket $ showPacket newkey)])
      else do
        return $ KikiSuccess (kd,report0)
generateSubkey _ kd _ = return kd

data Hostnames = Hostnames {
  gpgipv6addr :: SockAddr,
  verifiedOnionNames :: [L.ByteString],
  notationPacketNames :: [L.ByteString],
  cryptonomicName :: Maybe L.ByteString
}

-- |
-- Returns (ip6 fingerprint address,(onion names,other host names))
--
-- Requires a validly cross-signed tor key for each onion name returned.
-- (Signature checks are performed.)
getHostnames :: KeyData -> Hostnames
getHostnames (KeyData topmp _ uids subs) = Hostnames addr onames othernames Nothing
 where
    othernames = do
        mp <- flattenAllUids "" True uids
        let p = packet mp
        guard $ isSignaturePacket p
        uh <- unhashed_subpackets p
        case uh of
            NotationDataPacket True "hostname@" v
              -> return $ Char8.pack v
            _ -> mzero

    addr = fingerdress topk
    topk = packet topmp
    torkeys = getSubkeys CrossSigned topk subs "tor"

    -- subkeyPacket (SubKey k _ ) = k
    onames :: [L.ByteString]
    onames = map ( (<> ".onion")
                 . Char8.pack
                 . take 16
                 . torhash )
                 torkeys

hasFingerDress :: KeyDB -> SockAddr -> Bool
hasFingerDress db addr | socketFamily addr/=AF_INET6 = False
hasFingerDress db addr = pre=="fd" && isJust (selectPublicKey (KeyGrip g',Nothing) db)
 where
    (pre,g) = splitAt 2 $ filter (/=':') $ Hosts.inet_ntop addr
    g' = map toUpper g

-- We return into IO in case we want to make a signature here.
setHostnames :: IPsToWriteToHostsFile -> Hosts.Hosts -> KeyData -> IO KeyData
setHostnames (IPsToWriteToHostsFile outgoing_names) hosts kd@(KeyData topmp topsigs uids subs) =
    -- TODO: we are removing the origin from the UID OriginMap,
    --       when we should be removing origins from the locations
    --       field of the sig's MappedPacket records.
    -- Call getHostnames and compare to see if no-op.
    if pred || pred2
        then {- trace (unlines [ "setHostnames NO-OP: gpg: "++show (map Char8.unpack onions, map Char8.unpack names0)
                             , "                   file: "++show (map Char8.unpack names)
                             , "                   pred: "++show (pred addr)]) -}
                    (return kd)
        else do
    -- We should be sure to remove origins so that the data is written
    --   (but only if something changed).
    -- Filter all hostnames present in uids
    -- Write notations into first uid
    {-
    trace (unlines [ "setHostnames ACTION: gpg: "++show (map Char8.unpack onions, map Char8.unpack names0)
                   , "                    file: "++show (map Char8.unpack names) ]) $ do
    -}
    return $ KeyData topmp topsigs uids1 subs
 where
    pred = addr `elem` outgoing_names
    addr = fingerdress $ packet topmp
    names :: [Char8.ByteString]
    names = Hosts.namesForAddress addr hosts
    pred2 = gotNonOnions == namesWithoutGotOnions

    Hostnames _ gotOnions gotNonOnions cryptonomic = getHostnames kd

    namesWithoutGotOnions = names \\ gotOnions
    notations             = map (NotationDataPacket True "hostname@" . Char8.unpack) namesWithoutGotOnions
    isName (NotationDataPacket True "hostname@" _) = True
    isName _                                       = False
    uids0 = fmap zapIfHasName uids
    fstuid = UidString $ head $ do
        p <- map packet $ flattenAllUids "" True uids
        maybeToList $ isUserID p
    uids1 = Map.adjust addnames fstuid uids0
    addnames (sigs,om) = (fmap f ss ++ ts, om ) -- XXX: removed om=Map.empty, preserve UserId origin
     where
        (ss,ts) = splitAt 1 sigs
        f (sig,tm) = if isSignaturePacket (packet sig) then (sig { packet = p', locations=Map.empty }, tm)
                                                       else (sig, tm)
         where p' = (packet sig) { unhashed_subpackets=uh }
               uh = unhashed_subpackets (packet sig) ++ notations
    zapIfHasName (sigs,om) = if or bs then (sigs',om)  -- XXX: removed om=Map.empty to preserve UserID origin
                                      else (sigs,om)
     where
        (bs, sigs') = unzip $ map unhash sigs

        unhash (sig,tm) = ( not (null ns)
                          , ( sig { packet = p', locations = Map.empty }
                            , tm ) )
         where
            psig = packet sig
            p' = if isSignaturePacket psig then psig { unhashed_subpackets = ps }
                                           else psig
            uh = unhashed_subpackets psig
            (ns,ps) = partition isName uh

decode_btc_key ::
  Enum timestamp => timestamp -> String -> Maybe (Word8, Message)
decode_btc_key timestamp str = do
    (network_id,us) <- base58_decode str
    return . (network_id,) $ Message $ do
        let d = foldl' (\a b->a*256+b) 0 (map fromIntegral us :: [Integer])
            {-
            xy = secp256k1_G `pmul` d
            x = getx xy
            y = gety xy
            -- y² = x³ + 7 (mod p)
            y' = sqrtModP' (applyCurve secp256k1_curve x) (getp secp256k1_curve)
            y'' = sqrtModPList (applyCurve secp256k1_curve x) (getp secp256k1_curve)
            -}
            secp256k1 = ECC.getCurveByName ECC.SEC_p256k1
            ECC.Point x y = ECC.ecc_g $ ECC.common_curve secp256k1
            -- pub = cannonical_eckey x y
            -- hash = S.cons network_id . RIPEMD160.hash . SHA256.hash . S.pack $  pub
            -- address = base58_encode hash
            -- pubstr = concatMap (printf "%02x") $ pub
            -- _ = pubstr :: String
        return $ {- trace (unlines ["pub="++show pubstr
                                ,"add="++show address
                                ,"y  ="++show y
                                ,"y' ="++show y'
                                ,"y''="++show y'']) -}
            SecretKeyPacket
            { version = 4
            , timestamp = toEnum (fromEnum timestamp)
            , key_algorithm = ECDSA
            , key = [ -- public fields...
                     ('c',MPI secp256k1_id) -- secp256k1 (bitcoin curve)
                    ,('l',MPI 256)
                    ,('x',MPI x)
                    ,('y',MPI y)
                    -- secret fields
                    ,('d',MPI d)
                    ]
            , s2k_useage = 0
            , s2k = S2K 100 ""
            , symmetric_algorithm = Unencrypted
            , encrypted_data = ""
            , is_subkey = True
            }

-- DER-encoded elliptic curve ids
-- nistp256_id  = 0x2a8648ce3d030107
secp256k1_id :: Integer
secp256k1_id = 0x2b8104000a
-- "\x2a\x86\x48\xce\x3d\x03\x01\x07"
{-     OID                  Curve description              Curve name
    ----------------------------------------------------------------
    1.2.840.10045.3.1.7  NIST Curve P-256 [FIPS 186-2]  "NIST P-256"
    1.3.132.0.34         NIST Curve P-384 [FIPS 186-2]  "NIST P-384"
    1.3.132.0.35         NIST Curve P-521 [FIPS 186-2]  "NIST P-521"

    Implementations MUST implement "NIST P-256", "NIST P-384" and "NIST
    P-521".  The hexadecimal representation used in the public and
    private key encodings are:

    Curve Name   Len  Hexadecimal representation of the OID
    ----------------------------------------------------------------
    "NIST P-256"  8   0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x03, 0x01, 0x07
    "NIST P-384"  6   0x05, 0x2B, 0x81, 0x04, 0x00, 0x22
    "NIST P-521"  6   0x05, 0x2B, 0x81, 0x04, 0x00, 0x23
-}



dbInsertPacket :: KeyData -> FilePath -> (Int,(Packet,Packet,(Packet,Map.Map FilePath Packet))) -> Maybe KeyData
dbInsertPacket kd filename (n,(top,sub,ptt@(p,trustmap))) = update (Just kd)
 where
    asMapped n p = mappedPacketWithHint filename p n
    asSigAndTrust n (p,tm) = (asMapped n p,tm)

    -- NOTE:
    --  if a keyring file has both a public key packet and a secret key packet
    --  for the same key, then only one of them will survive, which ever is
    --  later in the file.
    --
    --  This is due to the use of statements like
    --      (Map.insert filename (origin p n) (locations key))
    --
    update :: Maybe KeyData -> Maybe KeyData
    update v | isKey p && not (is_subkey p)
          = case v of
             Nothing -> Just $ KeyData (asMapped n p) [] Map.empty Map.empty
             Just (KeyData key sigs uids subkeys) | keykey (packet key) == keykey p
                     -> Just $ KeyData (mergeKeyPacket "master keys" key $ asMapped n p)
                                       sigs
                                       uids
                                       subkeys
             _       -> error . concat $ ["Unexpected master key merge error: "
                                         ,show (fingerprint top, fingerprint p)]
    update (Just (KeyData key sigs uids subkeys)) | isKey p && is_subkey p
          = Just $ KeyData key sigs uids (Map.alter (mergeSubkey n p) (keykey p) subkeys)
    update (Just (KeyData key sigs uids subkeys)) | Just uid <- isUserID p
          = Just $ KeyData key sigs (Map.alter (mergeUid n ptt) (UidString uid) uids)
                                    subkeys
    update (Just (KeyData key sigs uids subkeys))
          = case sub of
             MarkerPacket    -> Just $ KeyData key (mergeSig (first (flip (mappedPacketWithHint filename) n) ptt) sigs) uids subkeys
             UserIDPacket uid-> Just $ KeyData key
                                               sigs
                                               (Map.alter (mergeUidSig n ptt) (UidString uid) uids)
                                               subkeys
             _  | isKey sub  -> Just $ KeyData key
                                               sigs
                                               uids
                                               (Map.alter (mergeSubSig n ptt) (keykey sub) subkeys)
             _ -> error $ "Unexpected PGP packet 1: "++(words (show p) >>= take 1)
    update _ = error $ "Unexpected PGP packet 2: "++(words (show p) >>= take 1)

    mergeSubkey :: Int -> Packet -> Maybe SubKey -> Maybe SubKey
    mergeSubkey n p Nothing                  = Just $ SubKey (asMapped n p) []
    mergeSubkey n p (Just (SubKey key sigs)) = Just $
        SubKey (mergeKeyPacket "subs" key $ asMapped n p)
               sigs

    mergeUid :: Int ->(Packet,a) -> Maybe ([SigAndTrust],OriginMap) -> Maybe ([SigAndTrust],OriginMap)
    mergeUid n (UserIDPacket s,_) Nothing         = Just ([],Map.singleton filename (origin MarkerPacket n))
    mergeUid n (UserIDPacket s,_) (Just (sigs,m)) = Just (sigs, Map.insert filename (origin MarkerPacket n) m)
    mergeUid n p _ = error $ "Unable to merge into UID record: " ++whatP p

    whatP (a,_) = concat . take 1 . words . show $ a


    mergeUidSig n sig (Just (sigs,m)) = Just (mergeSig (first (flip (mappedPacketWithHint filename) n) sig) sigs, m)
    mergeUidSig n sig Nothing     = Just ([asSigAndTrust n sig],Map.empty)

    mergeSubSig n sig (Just (SubKey key sigs)) = Just $ SubKey key (mergeSig (first (flip (mappedPacketWithHint filename) n) sig) sigs)
    mergeSubSig n sig Nothing = error $
        "Unable to merge subkey signature: "++(words (show sig) >>= take 1)


instance ASN1Object RSAPrivateKey where
    toASN1 rsa@(RSAPrivateKey {})
        = \xs -> Start Sequence
               : IntVal 0
               : mpiVal rsaN
               : mpiVal rsaE
               : mpiVal rsaD
               : mpiVal rsaP
               : mpiVal rsaQ
               : mpiVal rsaDmodP1
               : mpiVal rsaDmodQminus1
               : mpiVal rsaCoefficient
               : End Sequence
               : xs
                  where mpiVal f = IntVal x where MPI x = f rsa

    fromASN1 ( Start Sequence
             : IntVal _ -- version
             : IntVal n
             : IntVal e
             : IntVal d
             : IntVal p
             : IntVal q
             : IntVal dmodp1
             : IntVal dmodqminus1
             : IntVal coefficient
             : ys) =
        Right ( privkey, tail $ dropWhile notend ys)
         where
            notend (End Sequence) = False
            notend _              = True
            privkey = RSAPrivateKey
                { rsaN = MPI n
                , rsaE = MPI e
                , rsaD = MPI d
                , rsaP = MPI p
                , rsaQ = MPI q
                , rsaDmodP1 = MPI dmodp1
                , rsaDmodQminus1 = MPI dmodqminus1
                , rsaCoefficient = MPI coefficient
                }
    fromASN1 _ =
        Left "fromASN1: RSAPrivateKey: unexpected format"


readSecretPEMFile :: InputFile -> IO [SecretPEMData]
readSecretPEMFile fname = do
    -- warn $ fname ++ ": reading ..."
    let ctx = InputFileContext "" ""
    -- Note: The key's timestamp is included in it's fingerprint.
    --       Therefore, we should attempt to preserve it.
    stamp <- getInputFileTime ctx fname
    input <- readInputFileL ctx fname
    let edta = scanAndParse (fmap Left dateParser <> fmap Right (pkcs1 <> cert)) $ Char8.lines input
        pkcs1 = fmap (parseRSAPrivateKey . pemBlob)
                    $ pemParser $ Just "RSA PRIVATE KEY"
        cert  = fmap (fmap PEMCertificate . parseCertBlob False . pemBlob)
                    $ pemParser $ Just "CERTIFICATE"
        parseRSAPrivateKey dta = do
           let e = decodeASN1 DER dta
           asn1 <- either (const $ mzero) return e
           rsa <- either (const mzero) (return . fst) (fromASN1 asn1)
           let _ = rsa :: RSAPrivateKey
           return $ PEMPacket $ rsaToPGP stamp rsa
        dta = catMaybes $ map snd $ scanl mergeDate (stamp,Nothing) edta
        mergeDate (_,obj) (Left tm) = (fromTime tm,obj)
        mergeDate (tm,_) (Right (Just (PEMPacket key))) = (tm,Just $ PEMPacket key')
            where key' = if tm < fromTime (timestamp key)
                            then key { timestamp = fromTime tm }
                            else key
        mergeDate (tm,_) (Right mb) = (tm,mb)
    return $ dta


readSecretDNSFile :: InputFile -> IO Packet
readSecretDNSFile fname = do
    let ctx = InputFileContext "" ""
    stamp <- getInputFileTime ctx fname
    input <- readInputFileL ctx fname
    let kvs = map ( second (Char8.dropWhile isSpace . Char8.drop 1)
                  . Char8.break (==':'))
               $ Char8.lines input
        alg = maybe RSA parseAlg $ lookup "Algorithm" kvs
        parseAlg spec = case Char8.words spec of
                            nstr:_ -> case read (Char8.unpack nstr) :: Int of
                                            2  -> DH
                                            3  -> DSA -- SHA1
                                            5  -> RSA -- SHA1
                                            6  -> DSA -- NSEC3-SHA1 (RFC5155)
                                            7  -> RSA -- RSASHA1-NSEC3-SHA1 (RFC5155)
                                            8  -> RSA -- SHA256
                                            10 -> RSA -- SHA512 (RFC5702)
                                            -- 12 -> GOST
                                            13 -> ECDSA -- P-256 SHA256 (RFC6605)
                                            14 -> ECDSA -- P-384 SHA384 (RFC6605)
                            _ -> RSA
    case alg of
        RSA -> return $ rsaToPGP stamp $ fromJust $ extractRSAKeyFields kvs

spemPacket :: SecretPEMData -> Maybe Packet
spemPacket (PEMPacket p) = Just p
spemPacket _             = Nothing

spemCert :: SecretPEMData -> Maybe ParsedCert
spemCert (PEMCertificate p) = Just p
spemCert _                  = Nothing

fingerdress :: Packet -> SockAddr
fingerdress topk = fromMaybe zero $ Hosts.inet_pton addr_str
 where
    zero = SockAddrInet 0 0
    addr_str = colons $  "fd" ++ drop 10 (map toLower $ show $ fingerprint topk)
    colons (a:b:c:d:xs@(_:_)) = [a,b,c,d,':'] ++ colons xs
    colons xs                 = xs

getSubkeys :: SubkeyStatus -> Packet -> Map.Map KeyKey SubKey -> String -> [Packet]
getSubkeys ck topk subs tag = do
        SubKey k sigs <- Map.elems subs
        let subk = packet k
        let sigs' = do
                -- require tag
                torsig <- filter (has_tag tag) $ map (packet . fst) sigs

                -- require parent's signature
                when (ck > Unsigned) $ do
                    sig <- (signatures $ Message [topk,subk,torsig])
                    let v = verify (Message [topk]) sig
                    -- Require parent's signature
                    guard (not . null $ signatures_over v)

                -- require child's back signature
                when (ck == CrossSigned ) $ do
                    let unhashed = unhashed_subpackets torsig
                        subsigs = mapMaybe backsig unhashed
                        -- This should consist only of 0x19 values
                        -- subtypes = map signature_type subsigs
                    -- subtyp <- subtypes
                    -- guard (subtyp == 0x19)
                    sig' <- signatures . Message $ [topk,subk]++subsigs
                    let v' = verify (Message [subk]) sig'
                    -- Require subkey's signature
                    guard . not . null $ signatures_over v'
                return torsig
        guard (not $ null sigs')
        return subk

socketFamily :: SockAddr -> Family
socketFamily (SockAddrInet _ _) = AF_INET
socketFamily (SockAddrInet6 {}) = AF_INET6
socketFamily (SockAddrUnix _)   = AF_UNIX

selectPublicKey :: (KeySpec,Maybe String) -> KeyDB -> Maybe Packet
selectPublicKey (spec,mtag) db = selectKey0 True (spec,mtag) db

parseCertBlob :: Bool -> ByteString -> Maybe ParsedCert
parseCertBlob comp bs = do
    asn1 <- either (const Nothing) Just
                $ decodeASN1 DER bs
    let asn1' = drop 2 asn1
    cert <- either (const Nothing) (Just . fst) (fromASN1 asn1')
    let _ = cert :: X509.Certificate
        notBefore :: UTCTime
        notBefore =  toUTC ( timeFromElapsedP (timeGetElapsedP vincentTime) :: CTime) -- nanoToUTCTime nano
            where (vincentTime,_) = X509.certValidity cert
    case X509.certPubKey cert of
        X509.PubKeyRSA key -> do
            let withoutkey =
                    let ekey = toStrict $ encodeASN1 DER (toASN1 key [])
                        (pre,post) = S.breakSubstring ekey $ toStrict bs
                        post' = S.drop (S.length ekey) post
                        len :: Word16
                        len = if S.null post then maxBound
                                             else fromIntegral $ S.length pre
                    in if len < 4096
                        then encode len <> GZip.compress (Char8.fromChunks [pre,post'])
                        else bs
            return
                ParsedCert { pcertKey = packetFromPublicRSAKey notBefore
                                                               (MPI $ RSA.public_n key)
                                                               (MPI $ RSA.public_e key)
                           , pcertTimestamp = notBefore
                           , pcertBlob = if comp then withoutkey
                                                 else bs
                           }
        _ -> Nothing

rsaToPGP :: TimeUtil.IsUTC a => a -> RSAPrivateKey -> Packet
rsaToPGP stamp rsa = SecretKeyPacket
                { version = 4
                , timestamp = fromTime stamp -- toEnum (fromEnum stamp)
                , key_algorithm = RSA
                , key = [ -- public fields...
                         ('n',rsaN rsa)
                        ,('e',rsaE rsa)
                        -- secret fields
                        ,('d',rsaD rsa)
                        ,('p',rsaQ rsa) -- Note: p & q swapped
                        ,('q',rsaP rsa) -- Note: p & q swapped
                        ,('u',rsaCoefficient rsa)
                        ]
                -- , ecc_curve = def
                , s2k_useage = 0
                , s2k = S2K 100 ""
                , symmetric_algorithm = Unencrypted
                , encrypted_data = ""
                , is_subkey = True
                }

extractRSAKeyFields :: [(ByteString,ByteString)] -> Maybe RSAPrivateKey
extractRSAKeyFields kvs = do
    let kvs' = mapMaybe  (\(k,v) -> (k,) <$> parseField v) kvs
    n <- lookup "Modulus" kvs'
    e <- lookup "PublicExponent" kvs'
    d <- lookup "PrivateExponent" kvs'
    p <- lookup "Prime1" kvs' -- p
    q <- lookup "Prime2" kvs' -- q
    dmodp1 <- lookup "Exponent1" kvs' -- dP = d `mod` (p - 1)
    dmodqminus1 <- lookup "Exponent2" kvs' -- dQ = d `mod` (q - 1)
    u <- lookup "Coefficient" kvs'
    {-
    case (d,p,dmodp1) of
        (MPI dd, MPI pp, MPI x) | x == dd `mod` (pp-1) -> return ()
        _ -> error "dmodp fail!"
    case (d,q,dmodqminus1) of
        (MPI dd, MPI qq, MPI x) | x == dd `mod` (qq-1) -> return ()
        _ -> error "dmodq fail!"
    -}
    return $ RSAPrivateKey
        { rsaN = n
        , rsaE = e
        , rsaD = d
        , rsaP = p
        , rsaQ = q
        , rsaDmodP1 = dmodp1
        , rsaDmodQminus1 = dmodqminus1
        , rsaCoefficient = u }
 where
    parseField blob = MPI <$> m
     where m = bigendian <$> functorToMaybe (convertFromBase Base64 $ Char8.toStrict blob)
    bigendian bs = snd $ S.foldl' (\(c,a) w8 -> (c-1, a + 256^c * fromIntegral w8)) (nlen-1,0) bs
     where
        nlen = S.length bs


-- TODO: Data.ByteString.Lazy now exports this.
toStrict :: L.ByteString -> S.ByteString
toStrict = foldr1 (<>) . L.toChunks

packetFromPublicRSAKey :: UTCTime -> MPI -> MPI -> Packet
packetFromPublicRSAKey notBefore n e =
    PublicKeyPacket { version = 4
                    , timestamp = round $ utcTimeToPOSIXSeconds notBefore
                    , key_algorithm = RSA
                    , key = [('n',n),('e',e)]
                    , is_subkey = True
                    , v3_days_of_validity = Nothing
                    }