diff options
| -rw-r--r-- | CHANGELOG | 8 | ||||
| -rw-r--r-- | Crypto.hs | 117 | ||||
| -rw-r--r-- | Remote/Helper/Chunked.hs | 6 | ||||
| -rw-r--r-- | Types/Crypto.hs | 1 | ||||
| -rw-r--r-- | Types/GitConfig.hs | 7 | ||||
| -rw-r--r-- | Utility/StatelessOpenPGP.hs | 25 | ||||
| -rw-r--r-- | doc/todo/support_using_Stateless_OpenPGP_instead_of_gpg.mdwn | 20 |
7 files changed, 116 insertions, 68 deletions
@@ -2,10 +2,14 @@ git-annex (10.20231228) UNRELEASED; urgency=medium * info: Added "annex sizes of repositories" table to the overall display. * import: Sped up import from special remotes. - * assistant: When generating a gpg secret key, avoid hardcoding the - key algorithm and size. + * Support using commands that implement the Stateless OpenPGP command line + interface, as an alternative to gpg. + Currently only supported for encryption=shared special remotes, + when annex.shared-sop-command is configured. * test: Test a specified Stateless OpenPGP command when run with eg --test-git-config annex.shared-sop-command=sqop + * assistant: When generating a gpg secret key, avoid hardcoding the + key algorithm and size. -- Joey Hess <id@joeyh.name> Fri, 29 Dec 2023 11:52:06 -0400 @@ -1,7 +1,6 @@ {- git-annex crypto - - - Currently using gpg; could later be modified to support different - - crypto backends if necessary. + - Currently using gpg by default, or optionally stateless OpenPGP. - - Copyright 2011-2024 Joey Hess <id@joeyh.name> - @@ -32,7 +31,7 @@ module Crypto ( readBytesStrictly, encrypt, decrypt, - LensGpgEncParams(..), + LensEncParams(..), prop_HmacSha1WithCipher_sane ) where @@ -40,6 +39,7 @@ module Crypto ( import qualified Data.ByteString as S import qualified Data.ByteString.Lazy as L import Control.Monad.IO.Class +import qualified Data.ByteString.Short as S (toShort) import Annex.Common import qualified Utility.Gpg as Gpg @@ -48,29 +48,33 @@ import Types.Crypto import Types.Remote import Types.Key import Annex.SpecialRemote.Config -import qualified Data.ByteString.Short as S (toShort) +import Utility.Tmp.Dir + +{- The number of bytes of entropy used to generate a Cipher. + - + - Since a Cipher is base-64 encoded, the actual size of a Cipher + - is larger than this. 512 bytes of date base-64 encodes to 684 + - characters. + -} +cipherSize :: Int +cipherSize = 512 {- The beginning of a Cipher is used for MAC'ing; the remainder is used - - as the GPG symmetric encryption passphrase when using the hybrid - - scheme. Note that the cipher itself is base-64 encoded, hence the - - string is longer than 'cipherSize': 683 characters, padded to 684. + - as the symmetric encryption passphrase. - - - The 256 first characters that feed the MAC represent at best 192 - - bytes of entropy. However that's more than enough for both the - - default MAC algorithm, namely HMAC-SHA1, and the "strongest" + - Due to the base-64 encoding of the Cipher, the beginning 265 characters + - represent at best 192 bytes of entropy. However that's more than enough + - for both the default MAC algorithm, namely HMAC-SHA1, and the "strongest" - currently supported, namely HMAC-SHA512, which respectively need - (ideally) 64 and 128 bytes of entropy. - - - The remaining characters (320 bytes of entropy) is enough for GnuPG's - - symmetric cipher; unlike weaker public key crypto, the key does not - - need to be too large. + - The remaining characters (320 bytes of entropy) is enough for + - the symmetric encryption passphrase; unlike weaker public key crypto, + - that does not need to be too large. -} cipherBeginning :: Int cipherBeginning = 256 -cipherSize :: Int -cipherSize = 512 - cipherPassphrase :: Cipher -> S.ByteString cipherPassphrase (Cipher c) = S.drop cipherBeginning c cipherPassphrase (MacOnlyCipher _) = giveup "MAC-only cipher" @@ -80,7 +84,7 @@ cipherMac (Cipher c) = S.take cipherBeginning c cipherMac (MacOnlyCipher c) = c {- Creates a new Cipher, encrypted to the specified key id. -} -genEncryptedCipher :: LensGpgEncParams c => Gpg.GpgCmd -> c -> Gpg.KeyId -> EncryptedCipherVariant -> Bool -> IO StorableCipher +genEncryptedCipher :: LensEncParams c => Gpg.GpgCmd -> c -> Gpg.KeyId -> EncryptedCipherVariant -> Bool -> IO StorableCipher genEncryptedCipher cmd c keyid variant highQuality = do ks <- Gpg.findPubKeys cmd keyid random <- Gpg.genRandom cmd highQuality size @@ -106,7 +110,7 @@ genSharedPubKeyCipher cmd keyid highQuality = do {- Updates an existing Cipher, making changes to its keyids. - - When the Cipher is encrypted, re-encrypts it. -} -updateCipherKeyIds :: LensGpgEncParams encparams => Gpg.GpgCmd -> encparams -> [(Bool, Gpg.KeyId)] -> StorableCipher -> IO StorableCipher +updateCipherKeyIds :: LensEncParams encparams => Gpg.GpgCmd -> encparams -> [(Bool, Gpg.KeyId)] -> StorableCipher -> IO StorableCipher updateCipherKeyIds _ _ _ SharedCipher{} = giveup "Cannot update shared cipher" updateCipherKeyIds _ _ [] c = return c updateCipherKeyIds cmd encparams changes encipher@(EncryptedCipher _ variant ks) = do @@ -130,7 +134,7 @@ updateCipherKeyIds' cmd changes (KeyIds ks) = do listKeyIds = concat <$$> mapM (keyIds <$$> Gpg.findPubKeys cmd) {- Encrypts a Cipher to the specified KeyIds. -} -encryptCipher :: LensGpgEncParams c => Gpg.GpgCmd -> c -> Cipher -> EncryptedCipherVariant -> KeyIds -> IO StorableCipher +encryptCipher :: LensEncParams c => Gpg.GpgCmd -> c -> Cipher -> EncryptedCipherVariant -> KeyIds -> IO StorableCipher encryptCipher cmd c cip variant (KeyIds ks) = do -- gpg complains about duplicate recipient keyids let ks' = nub $ sort ks @@ -147,10 +151,10 @@ encryptCipher cmd c cip variant (KeyIds ks) = do MacOnlyCipher x -> x {- Decrypting an EncryptedCipher is expensive; the Cipher should be cached. -} -decryptCipher :: LensGpgEncParams c => Gpg.GpgCmd -> c -> StorableCipher -> IO Cipher +decryptCipher :: LensEncParams c => Gpg.GpgCmd -> c -> StorableCipher -> IO Cipher decryptCipher cmd c cip = decryptCipher' cmd Nothing c cip -decryptCipher' :: LensGpgEncParams c => Gpg.GpgCmd -> Maybe [(String, String)] -> c -> StorableCipher -> IO Cipher +decryptCipher' :: LensEncParams c => Gpg.GpgCmd -> Maybe [(String, String)] -> c -> StorableCipher -> IO Cipher decryptCipher' _ _ _ (SharedCipher t) = return $ Cipher t decryptCipher' _ _ _ (SharedPubKeyCipher t _) = return $ MacOnlyCipher t decryptCipher' cmd environ c (EncryptedCipher t variant _) = @@ -198,16 +202,23 @@ readBytesStrictly a h = liftIO (S.hGetContents h) >>= a {- Runs a Feeder action, that generates content that is symmetrically - encrypted with the Cipher (unless it is empty, in which case - - public-key encryption is used) using the given gpg options, and then - - read by the Reader action. + - public-key encryption is used), and then read by the Reader action. - - - Note that the Reader must fully consume gpg's input before returning. + - Note that the Reader must fully consume all input before returning. -} -encrypt :: (MonadIO m, MonadMask m, LensGpgEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a -encrypt cmd c cipher = case cipher of - Cipher{} -> Gpg.feedRead cmd (params ++ Gpg.stdEncryptionParams True) $ - cipherPassphrase cipher - MacOnlyCipher{} -> Gpg.feedRead' cmd $ params ++ Gpg.stdEncryptionParams False +encrypt :: (MonadIO m, MonadMask m, LensEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a +encrypt gpgcmd c cipher feeder reader = case cipher of + Cipher{} -> + let passphrase = cipherPassphrase cipher + in case statelessOpenPGPCommand c of + Just sopcmd -> withTmpDir "sop" $ \d -> + SOP.encryptSymmetric sopcmd passphrase + (SOP.EmptyDirectory d) + (statelessOpenPGPProfile c) + (SOP.Armoring False) + feeder reader + Nothing -> Gpg.feedRead gpgcmd (params ++ Gpg.stdEncryptionParams True) passphrase feeder reader + MacOnlyCipher{} -> Gpg.feedRead' gpgcmd (params ++ Gpg.stdEncryptionParams False) feeder reader where params = getGpgEncParams c @@ -215,12 +226,19 @@ encrypt cmd c cipher = case cipher of - Cipher (or using a private key if the Cipher is empty), and read by the - Reader action. - - - Note that the Reader must fully consume gpg's input before returning. + - Note that the Reader must fully consume all input before returning. - -} -decrypt :: (MonadIO m, MonadMask m, LensGpgEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a -decrypt cmd c cipher = case cipher of - Cipher{} -> Gpg.feedRead cmd params $ cipherPassphrase cipher - MacOnlyCipher{} -> Gpg.feedRead' cmd params +decrypt :: (MonadIO m, MonadMask m, LensEncParams c) => Gpg.GpgCmd -> c -> Cipher -> Feeder -> Reader m a -> m a +decrypt cmd c cipher feeder reader = case cipher of + Cipher{} -> + let passphrase = cipherPassphrase cipher + in case statelessOpenPGPCommand c of + Just sopcmd -> withTmpDir "sop" $ \d -> + SOP.decryptSymmetric sopcmd passphrase + (SOP.EmptyDirectory d) + feeder reader + Nothing -> Gpg.feedRead cmd params passphrase feeder reader + MacOnlyCipher{} -> Gpg.feedRead' cmd params feeder reader where params = Param "--decrypt" : getGpgDecParams c @@ -235,19 +253,26 @@ prop_HmacSha1WithCipher_sane = known_good == macWithCipher' HmacSha1 "foo" "bar" where known_good = "46b4ec586117154dacd49d664e5d63fdc88efb51" -class LensGpgEncParams a where - {- Base parameters for encrypting. Does not include specification +class LensEncParams a where + {- Base gpg parameters for encrypting. Does not include specification - of recipient keys. -} getGpgEncParamsBase :: a -> [CommandParam] - {- Parameters for encrypting. When the remote is configured to use + {- Gpg parameters for encrypting. When the remote is configured to use - public-key encryption, includes specification of recipient keys. -} getGpgEncParams :: a -> [CommandParam] - {- Parameters for decrypting. -} + {- Gpg parameters for decrypting. -} getGpgDecParams :: a -> [CommandParam] + {- Set when stateless OpenPGP should be used rather than gpg. + - It is currently only used for SharedEncryption and not the other + - schemes which use public keys. -} + statelessOpenPGPCommand :: a -> Maybe SOP.SOPCmd + {- When using stateless OpenPGP, this may be set to a profile + - which should be used instead of the default. -} + statelessOpenPGPProfile :: a -> Maybe SOP.SOPProfile {- Extract the GnuPG options from a pair of a Remote Config and a Remote - Git Config. -} -instance LensGpgEncParams (ParsedRemoteConfig, RemoteGitConfig) where +instance LensEncParams (ParsedRemoteConfig, RemoteGitConfig) where getGpgEncParamsBase (_c,gc) = map Param (remoteAnnexGnupgOptions gc) getGpgEncParams (c,gc) = getGpgEncParamsBase (c,gc) ++ {- When the remote is configured to use public-key encryption, @@ -261,9 +286,21 @@ instance LensGpgEncParams (ParsedRemoteConfig, RemoteGitConfig) where getRemoteConfigValue pubkeysField c _ -> [] getGpgDecParams (_c,gc) = map Param (remoteAnnexGnupgDecryptOptions gc) + statelessOpenPGPCommand (c,gc) = case remoteAnnexSharedSOPCommand gc of + Nothing -> Nothing + Just sopcmd -> + {- So far stateless OpenPGP is only supported + - for SharedEncryption, not other encryption + - methods that involve public keys. -} + case getRemoteConfigValue encryptionField c of + Just SharedEncryption -> Just sopcmd + _ -> Nothing + statelessOpenPGPProfile (_c,gc) = remoteAnnexSharedSOPProfile gc {- Extract the GnuPG options from a Remote. -} -instance LensGpgEncParams (RemoteA a) where +instance LensEncParams (RemoteA a) where getGpgEncParamsBase r = getGpgEncParamsBase (config r, gitconfig r) getGpgEncParams r = getGpgEncParams (config r, gitconfig r) getGpgDecParams r = getGpgDecParams (config r, gitconfig r) + statelessOpenPGPCommand r = statelessOpenPGPCommand (config r, gitconfig r) + statelessOpenPGPProfile r = statelessOpenPGPProfile (config r, gitconfig r) diff --git a/Remote/Helper/Chunked.hs b/Remote/Helper/Chunked.hs index 3e7f8a47e1..29b97b761a 100644 --- a/Remote/Helper/Chunked.hs +++ b/Remote/Helper/Chunked.hs @@ -115,7 +115,7 @@ numChunks = pred . fromJust . fromKey keyChunkNum . fst . nextChunkKeyStream - writes a whole L.ByteString at a time. -} storeChunks - :: LensGpgEncParams encc + :: LensEncParams encc => UUID -> ChunkConfig -> EncKey @@ -250,7 +250,7 @@ removeChunks remover u chunkconfig encryptor k = do - Handles decrypting the content when encryption is used. -} retrieveChunks - :: LensGpgEncParams encc + :: LensEncParams encc => Retriever -> UUID -> VerifyConfig @@ -391,7 +391,7 @@ retrieveChunks retriever u vc chunkconfig encryptor basek dest basep enc encc - into place. (And it may even already be in the right place..) -} writeRetrievedContent - :: LensGpgEncParams encc + :: LensEncParams encc => FilePath -> Maybe (Cipher, EncKey) -> encc diff --git a/Types/Crypto.hs b/Types/Crypto.hs index 38f4daeb10..2b3b065d71 100644 --- a/Types/Crypto.hs +++ b/Types/Crypto.hs @@ -35,6 +35,7 @@ data EncryptionMethod | HybridEncryption deriving (Typeable, Eq) +-- A base-64 encoded random value used for encryption. -- XXX ideally, this would be a locked memory region data Cipher = Cipher ByteString | MacOnlyCipher ByteString diff --git a/Types/GitConfig.hs b/Types/GitConfig.hs index b8158ea8e6..0c531fbf06 100644 --- a/Types/GitConfig.hs +++ b/Types/GitConfig.hs @@ -47,7 +47,7 @@ import Types.View import Config.DynamicConfig import Utility.HumanTime import Utility.Gpg (GpgCmd, mkGpgCmd) -import Utility.StatelessOpenPGP (SOPCmd(..)) +import Utility.StatelessOpenPGP (SOPCmd(..), SOPProfile(..)) import Utility.ThreadScheduler (Seconds(..)) import Utility.Url (Scheme, mkScheme) @@ -374,7 +374,7 @@ data RemoteGitConfig = RemoteGitConfig , remoteAnnexGnupgOptions :: [String] , remoteAnnexGnupgDecryptOptions :: [String] , remoteAnnexSharedSOPCommand :: Maybe SOPCmd - , remoteAnnexSharedSOPProfile :: Maybe String + , remoteAnnexSharedSOPProfile :: Maybe SOPProfile , remoteAnnexRsyncUrl :: Maybe String , remoteAnnexBupRepo :: Maybe String , remoteAnnexBorgRepo :: Maybe String @@ -444,7 +444,8 @@ extractRemoteGitConfig r remotename = do , remoteAnnexGnupgDecryptOptions = getoptions "gnupg-decrypt-options" , remoteAnnexSharedSOPCommand = SOPCmd <$> notempty (getmaybe "shared-sop-command") - , remoteAnnexSharedSOPProfile = notempty $ getmaybe "shared-sop-profile" + , remoteAnnexSharedSOPProfile = SOPProfile <$> + notempty (getmaybe "shared-sop-profile") , remoteAnnexRsyncUrl = notempty $ getmaybe "rsyncurl" , remoteAnnexBupRepo = getmaybe "buprepo" , remoteAnnexBorgRepo = getmaybe "borgrepo" diff --git a/Utility/StatelessOpenPGP.hs b/Utility/StatelessOpenPGP.hs index 35b4b17ccc..7a4c2063ca 100644 --- a/Utility/StatelessOpenPGP.hs +++ b/Utility/StatelessOpenPGP.hs @@ -9,9 +9,10 @@ module Utility.StatelessOpenPGP ( SOPCmd(..), - SopSubCmd, + SOPSubCmd, + SOPProfile(..), Password, - Profile, + EmptyDirectory(..), Armoring(..), encryptSymmetric, decryptSymmetric, @@ -37,18 +38,18 @@ import qualified Data.ByteString as B newtype SOPCmd = SOPCmd { unSOPCmd :: String } {- The subcommand to run eg encrypt. -} -type SopSubCmd = String +type SOPSubCmd = String + +newtype SOPProfile = SOPProfile String {- Note that SOP requires passwords to be UTF-8 encoded, and that they - may try to trim trailing whitespace. They may also forbid leading - whitespace, or forbid some non-printing characters. -} type Password = B.ByteString -type Profile = String - newtype Armoring = Armoring Bool -{- The path to an empty temporary directory. +{- The path to a sufficiently empty directory. - - This is unfortunately needed because of an infelicity in the SOP - standard, as documented in section 9.9 "Be Careful with Special @@ -61,6 +62,9 @@ newtype Armoring = Armoring Bool - special designators, an empty directory has to be provided, and the - command is run in that directory. Of course, this necessarily means - that any relative paths passed to the command have to be made absolute. + - + - The directory does not really have to be empty, it just needs to be one + - that should not contain any files with names starting with "@". -} newtype EmptyDirectory = EmptyDirectory FilePath @@ -70,7 +74,7 @@ encryptSymmetric => SOPCmd -> Password -> EmptyDirectory - -> Maybe Profile + -> Maybe SOPProfile -> Armoring -> (Handle -> IO ()) -> (Handle -> m a) @@ -84,7 +88,8 @@ encryptSymmetric sopcmd password emptydirectory mprofile armoring feeder reader Armoring True -> Nothing , Just "--as=binary" , case mprofile of - Just profile -> Just $ "--profile=" ++ profile + Just (SOPProfile profile) -> + Just $ "--profile=" ++ profile Nothing -> Nothing ] @@ -121,7 +126,7 @@ test_encrypt_decrypt_Symmetric a b password armoring v = catchBoolIO $ feedRead :: (MonadIO m, MonadMask m) => SOPCmd - -> SopSubCmd + -> SOPSubCmd -> [CommandParam] -> Password -> EmptyDirectory @@ -166,7 +171,7 @@ feedRead cmd subcmd params password emptydirectory feeder reader = do feedRead' :: (MonadIO m, MonadMask m) => SOPCmd - -> SopSubCmd + -> SOPSubCmd -> [CommandParam] -> Maybe EmptyDirectory -> (Handle -> IO ()) diff --git a/doc/todo/support_using_Stateless_OpenPGP_instead_of_gpg.mdwn b/doc/todo/support_using_Stateless_OpenPGP_instead_of_gpg.mdwn index 75bebba247..e6600e88a5 100644 --- a/doc/todo/support_using_Stateless_OpenPGP_instead_of_gpg.mdwn +++ b/doc/todo/support_using_Stateless_OpenPGP_instead_of_gpg.mdwn @@ -19,6 +19,14 @@ That example uses symmetric encryption, which is what git-annex uses for encryption=shared. So git-annex could use this or gpg to access the same encrypted special remote. +Update: That's implemented now, when annex.shared-sop-command is configured +it will be used for encryption=shared special remotes. It interoperates +fine with using gpg, as long as the sop command uses a compatable profile +(setting annex.shared-sop-profile = rfc4880 is probably a good idea). + +Leaving this todo open because there are other encryption schemes than +encryption=shared, for which using sop is not yet supported. + For the public key encryption used by the other encryption= schemes, sop would be harder to use, because it does not define any location to store private keys. Though it is possible to export gpg private keys @@ -39,14 +47,6 @@ It can detect if a password is needed by trying the sop operation without a password and checking for an exit code of 67. See [this issue on sop password prompting](https://gitlab.com/dkg/openpgp-stateless-cli/-/issues/64) -git-annex also uses gpg to generate random data for an encryption cipher -when setting up an encrypted special remote. Of course there are other ways -to generate random data, but it does make sense to use gpg or a similar -tool for this particular random data generation, since it's effectively a -secret key. And genRandom already using --armor. So when using sop, it -seems like it might make sense to use the `generate-key` command, and -extract the armored data from it. Although note that not all of that output -is random, the first several bytes are OpenPGP header that doesn't change -much. - See also: [[todo/whishlist__58___GPG_alternatives_like_AGE]] + +[[!meta title="support using Stateless OpenPGP instead of gpg for encryption methods other than encryption=shared"]] |