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|
{-# LANGUAGE OverloadedStrings, BangPatterns #-}
{- Copyright 2016 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Main where
import Types
import Tunables
import qualified CmdLine
import UI
import Encryption
import Entropy
import Benchmark
import Tests
import Cost
import SecretKey
import Share
import Storage
import Types.Server
import BackupLog
import AutoStart
import HTTP.Server
import ServerBackup
import qualified Gpg
import Data.Maybe
import Data.Time.Clock
import Data.Time.Calendar
import Data.Monoid
import Data.List
import Control.DeepSeq
import qualified Data.Text as T
import qualified Data.ByteString as B
import qualified Data.ByteString.UTF8 as BU8
import qualified Data.Set as S
import System.Posix.User (userGecos, getUserEntryForID, getEffectiveUserID)
main :: IO ()
main = do
cmdline <- CmdLine.get
ui <- selectUI (CmdLine.gui cmdline)
let mkt = CmdLine.customizeShareParams cmdline
(tunables, possibletunables) <- if CmdLine.testMode cmdline
then do
showInfo ui "Test mode"
"Keysafe is running in test mode. This is not secure, and should not be used with real secret keys!"
return (mkt testModeTunables, [mkt testModeTunables])
else return (mkt defaultTunables, map (mkt . snd) knownTunings)
dispatch cmdline ui tunables possibletunables
dispatch :: CmdLine.CmdLine -> UI -> Tunables -> [Tunables] -> IO ()
dispatch cmdline ui tunables possibletunables = do
mode <- CmdLine.selectMode cmdline
go mode (CmdLine.secretkeysource cmdline)
where
go CmdLine.Backup (Just secretkeysource) =
backup cmdline ui tunables secretkeysource
=<< getSecretKey secretkeysource
go CmdLine.Restore (Just secretkeydest) =
restore cmdline ui possibletunables secretkeydest
go CmdLine.Backup Nothing =
backup cmdline ui tunables Gpg.anyKey
=<< Gpg.getKeyToBackup ui
go CmdLine.Restore Nothing =
restore cmdline ui possibletunables Gpg.anyKey
go CmdLine.UploadQueued _ =
uploadQueued ui (CmdLine.localstoragedirectory cmdline)
go CmdLine.AutoStart _ =
autoStart cmdline tunables ui
go (CmdLine.Server) _ =
runServer
(CmdLine.localstoragedirectory cmdline)
(CmdLine.serverConfig cmdline)
go (CmdLine.BackupServer d) _ =
backupServer (CmdLine.localstoragedirectory cmdline) d
go (CmdLine.RestoreServer d) _ =
restoreServer (CmdLine.localstoragedirectory cmdline) d
go (CmdLine.Chaff hn) _ = storeChaff hn
(CmdLine.serverPort (CmdLine.serverConfig cmdline))
(CmdLine.chaffMaxDelay cmdline)
go CmdLine.Benchmark _ =
benchmarkTunables tunables
go CmdLine.Test _ =
runTests
backup :: CmdLine.CmdLine -> UI -> Tunables -> SecretKeySource -> SecretKey -> IO ()
backup cmdline ui tunables secretkeysource secretkey = do
installAutoStartFile
username <- userName
Name theirname <- case CmdLine.name cmdline of
Just n -> pure n
Nothing -> fromMaybe (error "Aborting on no username")
<$> promptName ui "Enter your name"
usernamedesc (Just username) validateName
go theirname
where
go theirname = do
cores <- fromMaybe 1 <$> getNumCores
Name othername <- case CmdLine.name cmdline of
Just n -> pure n
Nothing -> fromMaybe (error "aborting on no othername")
<$> promptName ui "Enter other name"
othernamedesc Nothing validateName
let name = Name (theirname <> " " <> othername)
(kek, passwordentropy) <- promptpassword name
let sis = shareIdents tunables name secretkeysource
let cost = getCreationCost kek <> getCreationCost sis
(r, queued, locs) <- withProgressIncremental ui "Encrypting and storing data"
(encryptdesc cost cores) $ \addpercent -> do
let esk = encrypt tunables kek secretkey
shares <- genShares esk tunables
_ <- esk `deepseq` addpercent 25
_ <- sis `seq` addpercent 25
let step = 50 `div` sum (map S.size shares)
storeShares (cmdLineStorageLocations cmdline) sis shares (addpercent step)
backuplog <- mkBackupLog $ backupMade (mapMaybe getServer locs) secretkeysource passwordentropy
case r of
StoreSuccess -> do
storeBackupLog backuplog
if queued
then do
willautostart <- isAutoStartFileInstalled
showInfo ui "Backup queued" $ "Some data was not sucessfully uploaded to servers, and has been queued for later upload."
++ if willautostart then "" else " Run keysafe --uploadqueued at a later point to finish the backup."
else showInfo ui "Backup success" "Your secret key was successfully encrypted and backed up."
StoreFailure s -> showError ui ("There was a problem storing your encrypted secret key: " ++ s)
StoreAlreadyExists -> do
showError ui $ unlines
[ "Another secret key is already being stored under the name you entered."
, "Please try again with a different name."
]
go theirname
promptpassword name = do
password <- fromMaybe (error "Aborting on no password")
<$> promptPassword ui True "Enter password" passworddesc
kek <- genKeyEncryptionKey tunables name password
passwordentropy <- getPasswordEntropy password name
let crackcost = estimateAttackCost spotAWS $
estimateBruteforceOf kek passwordentropy
let mincost = Dollars 100000
if crackcost < mincost
then do
showError ui $ "Weak password! It would cost only " ++ show crackcost ++ " to crack the password. Please think of a better one. More words would be good.."
promptpassword name
else do
(thisyear, _, _) <- toGregorian . utctDay
<$> getCurrentTime
ok <- promptQuestion ui "Password strength estimate"
(crackdesc crackcost thisyear)
"Is your password strong enough?"
if ok
then return (kek, passwordentropy)
else promptpassword name
keydesc = case secretkeysource of
GpgKey _ -> "gpg secret key"
KeyFile _ -> "secret key"
usernamedesc = unlines
[ "Keysafe is going to backup your " ++ keydesc ++ " securely."
, ""
, "You will be prompted for some information. To restore your " ++ keydesc
, "at a later date, you will need to remember and enter the same information."
, ""
, "To get started, what is your name?"
]
othernamedesc = unlines
[ "Now think of another name, which not many people know."
, "This will be used to make it hard for anyone else to find"
, "the backup of your " ++ keydesc ++ "."
, ""
, "Some suggestions:"
, ""
, otherNameSuggestions
, ""
, "Make sure to pick a name you will remember later,"
, "when you restore your " ++ keydesc ++ "."
]
passworddesc = unlines
[ "Pick a password that will be used to protect your secret key."
, ""
, "It's very important that this password be hard to guess."
, ""
, "And, it needs to be one that you will be able to remember years from now"
, "in order to restore your secret key."
]
crackdesc crackcost thisyear = unlines $
"Rough estimate of the cost to crack your password: " :
costOverTimeTable crackcost thisyear
encryptdesc cost cores = unlines
[ "This will probably take around " ++ showCostMinutes cores cost
, ""
, "(It's a feature that this takes a while; it makes it hard"
, "for anyone to find your data, or crack your password.)"
, ""
, "Please wait..."
]
otherNameSuggestions :: String
otherNameSuggestions = unlines $ map (" * " ++)
[ "Your high-school sweetheart."
, "Your first pet."
, "Your favorite teacher."
, "Your college roomate."
, "A place you like to visit."
]
restore :: CmdLine.CmdLine -> UI -> [Tunables] -> SecretKeySource -> IO ()
restore cmdline ui possibletunables secretkeydest = do
cores <- fromMaybe 1 <$> getNumCores
username <- userName
Name theirname <- case CmdLine.name cmdline of
Just n -> pure n
Nothing -> fromMaybe (error "Aborting on no username")
<$> promptName ui "Enter your name"
namedesc (Just username) validateName
Name othername <- case CmdLine.name cmdline of
Just n -> pure n
Nothing -> fromMaybe (error "aborting on no othername")
<$> promptName ui "Enter other name"
othernamedesc Nothing validateName
let name = Name (theirname <> " " <> othername)
password <- fromMaybe (error "Aborting on no password")
<$> promptPassword ui True "Enter password" passworddesc
let mksis tunables = shareIdents tunables name secretkeydest
r <- downloadInitialShares storagelocations ui mksis possibletunables
case r of
Nothing -> showError ui "No shares could be downloaded. Perhaps you entered the wrong name?"
Just (tunables, shares, sis, usedservers) -> do
let candidatekeys = candidateKeyEncryptionKeys tunables name password
let cost = getCreationCost candidatekeys
<> castCost (getDecryptionCost candidatekeys)
case combineShares tunables [shares] of
Left e -> showError ui e
Right esk -> do
final <- withProgress ui "Decrypting"
(decryptdesc cost cores) $ \setpercent ->
go tunables [shares] usedservers sis setpercent $
tryDecrypt candidatekeys esk
final =<< getPasswordEntropy password name
where
storagelocations = cmdLineStorageLocations cmdline
go tunables firstshares firstusedservers sis setpercent r = case r of
DecryptFailed -> return $ \_ ->
showError ui "Decryption failed! Probably you entered the wrong password."
DecryptSuccess secretkey -> do
_ <- setpercent 100
writeSecretKey secretkeydest secretkey
return $ \passwordentropy -> do
showInfo ui "Success" "Your secret key was successfully restored!"
-- Since the key was restored, we know it's
-- backed up; log that.
backuplog <- mkBackupLog $
backupMade firstusedservers secretkeydest passwordentropy
storeBackupLog backuplog
DecryptIncomplete kek -> do
-- Download shares for another chunk.
(nextshares, sis', nextusedservers)
<- retrieveShares storagelocations sis (return ())
let shares = firstshares ++ [nextshares]
let usedservers = nub (firstusedservers ++ nextusedservers)
case combineShares tunables shares of
Left e -> return $ \_ -> showError ui e
Right esk ->
go tunables shares usedservers sis' setpercent $
decrypt kek esk
namedesc = unlines
[ "When you backed up your secret key, you entered some information."
, "To restore it, you'll need to remember what you entered back then."
, ""
, "To get started, what is your name?"
]
othernamedesc = unlines
[ "What other name did you enter when you backed up your secret key?"
, ""
, "Back then, you were given some suggestions, like these:"
, ""
, otherNameSuggestions
]
passworddesc = unlines
[ "Enter the password to unlock your secret key."
]
decryptdesc cost cores = unlines
[ "This will probably take around " ++ showCostMinutes cores cost
, ""
, "(It's a feature that this takes so long; it prevents cracking your password.)"
, ""
, "Please wait..."
]
-- | Try each possible tunable until the initial set of
-- shares are found, and return the shares, and
-- ShareIdents to download subsequent sets.
downloadInitialShares
:: StorageLocations
-> UI
-> (Tunables -> ShareIdents)
-> [Tunables]
-> IO (Maybe (Tunables, S.Set Share, ShareIdents, [Server]))
downloadInitialShares storagelocations ui mksis possibletunables = do
cores <- fromMaybe 1 <$> getNumCores
withProgressIncremental ui "Downloading encrypted data" (message cores) $ \addpercent -> do
go possibletunables addpercent
where
go [] _ = return Nothing
go (tunables:othertunables) addpercent = do
-- Just calculating the hash to generate the stream of idents
-- probably takes most of the time.
let !sis = mksis tunables
addpercent 50
let m = totalObjects (shareParams tunables)
let step = 50 `div` m
(shares, sis', usedservers) <- retrieveShares storagelocations sis (addpercent step)
if S.null shares
then go othertunables addpercent
else return $ Just (tunables, shares, sis', usedservers)
possiblesis = map mksis possibletunables
message cores = unlines
[ "This will probably take around "
++ showCostMinutes cores (mconcat $ map getCreationCost possiblesis)
, ""
, "(It's a feature that this takes a while; it makes it hard"
, "for anyone else to find your data.)"
, ""
, "Please wait..."
]
validateName :: Name -> Maybe Problem
validateName (Name n)
| B.length n < 2 = Just "The name should be at least 2 letters long."
| otherwise = Nothing
userName :: IO Name
userName = do
u <- getUserEntryForID =<< getEffectiveUserID
return $ Name $ BU8.fromString $ takeWhile (/= ',') (userGecos u)
cmdLineStorageLocations :: CmdLine.CmdLine -> StorageLocations
cmdLineStorageLocations cmdline
| CmdLine.localstorage cmdline = localStorageLocations lsd
| otherwise = networkStorageLocations lsd
where
lsd = CmdLine.localstoragedirectory cmdline
getPasswordEntropy :: Password -> Name -> IO (Entropy UnknownPassword)
getPasswordEntropy password name = do
username <- userName
let badwords = concatMap namewords [name, username]
return $ calcPasswordEntropy password badwords
where
namewords (Name nb) = words (BU8.toString nb)
uploadQueued :: UI -> Maybe LocalStorageDirectory -> IO ()
uploadQueued ui d = do
problems <- tryUploadQueued d
if null problems
then return ()
else showError ui ("Problem uploading queued data to servers:\n\n" ++ unlines problems ++ "\n\nYour secret keys have not yet been backed up.")
autoStart :: CmdLine.CmdLine -> Tunables -> UI -> IO ()
autoStart cmdline tunables ui = do
-- Upload queued first, before making any more backups that might
-- queue more.
uploadQueued ui (CmdLine.localstoragedirectory cmdline)
-- Ask about backing up any gpg secret key that has not been backed up
-- or asked about before. If there are multiple secret keys, only
-- the first one is asked about, to avoid flooding with prompts
-- if the user for some reason generated a lot of secret keys.
ls <- readBackupLogs
ks <- Gpg.listSecretKeys
case filter (\(_, k) -> not $ any (matchesSecretKeySource (GpgKey k)) ls) ks of
[] -> return ()
((Name n,kid@(KeyId kt)):_) -> do
let kdesc = if length ks < 2
then "gpg secret key "
else "gpg secret key for " ++ BU8.toString n ++ " (" ++ T.unpack kt ++ ") "
ans <- promptQuestion ui ("Back up gpg secret key?")
("Your " ++ kdesc ++ " has not been backed up by keysafe yet.\n\nKeysafe can securely back up the secret key to the cloud, protected with a password.\n")
"Do you want to back up the gpg secret key now?"
if ans
then backup cmdline ui tunables (GpgKey kid)
=<< Gpg.getSecretKey kid
else storeBackupLog
=<< mkBackupLog (BackupSkipped (GpgKey kid))
|