git-annex/Types/Key.hs
Joey Hess 4315bb9e42
add retrievalSecurityPolicy
This will be used to protect against CVE-2018-10859, where an encrypted
special remote is fed the wrong encrypted data, and so tricked into
decrypting something that the user encrypted with their gpg key and did
not store in git-annex.

It also protects against CVE-2018-10857, where a remote follows a http
redirect to a file:// url or to a local private web server. While that's
already been prevented in git-annex's own use of http, external special
remotes, hooks, etc use other http implementations and could still be
vulnerable.

The policy is not yet enforced, this commit only adds the appropriate
metadata to remotes.

This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.
2018-06-21 11:36:36 -04:00

175 lines
7.1 KiB
Haskell

{- git-annex Key data type
-
- Copyright 2011-2018 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
{-# LANGUAGE CPP #-}
module Types.Key where
import Utility.PartialPrelude
import System.Posix.Types
{- A Key has a unique name, which is derived from a particular backend,
- and may contain other optional metadata. -}
data Key = Key
{ keyName :: String
, keyVariety :: KeyVariety
, keySize :: Maybe Integer
, keyMtime :: Maybe EpochTime
, keyChunkSize :: Maybe Integer
, keyChunkNum :: Maybe Integer
} deriving (Eq, Ord, Read, Show)
{- A filename may be associated with a Key. -}
newtype AssociatedFile = AssociatedFile (Maybe FilePath)
deriving (Show, Eq, Ord)
{- There are several different varieties of keys. -}
data KeyVariety
= SHA2Key HashSize HasExt
| SHA3Key HashSize HasExt
| SKEINKey HashSize HasExt
| Blake2bKey HashSize HasExt
| Blake2sKey HashSize HasExt
| Blake2spKey HashSize HasExt
| SHA1Key HasExt
| MD5Key HasExt
| WORMKey
| URLKey
-- Some repositories may contain keys of other varieties,
-- which can still be processed to some extent.
| OtherKey String
deriving (Eq, Ord, Read, Show)
{- Some varieties of keys may contain an extension at the end of the
- keyName -}
newtype HasExt = HasExt Bool
deriving (Eq, Ord, Read, Show)
newtype HashSize = HashSize Int
deriving (Eq, Ord, Read, Show)
hasExt :: KeyVariety -> Bool
hasExt (SHA2Key _ (HasExt b)) = b
hasExt (SHA3Key _ (HasExt b)) = b
hasExt (SKEINKey _ (HasExt b)) = b
hasExt (Blake2bKey _ (HasExt b)) = b
hasExt (Blake2sKey _ (HasExt b)) = b
hasExt (Blake2spKey _ (HasExt b)) = b
hasExt (SHA1Key (HasExt b)) = b
hasExt (MD5Key (HasExt b)) = b
hasExt WORMKey = False
hasExt URLKey = False
hasExt (OtherKey s) = end s == "E"
sameExceptExt :: KeyVariety -> KeyVariety -> Bool
sameExceptExt (SHA2Key sz1 _) (SHA2Key sz2 _) = sz1 == sz2
sameExceptExt (SHA3Key sz1 _) (SHA3Key sz2 _) = sz1 == sz2
sameExceptExt (SKEINKey sz1 _) (SKEINKey sz2 _) = sz1 == sz2
sameExceptExt (Blake2bKey sz1 _) (Blake2bKey sz2 _) = sz1 == sz2
sameExceptExt (Blake2sKey sz1 _) (Blake2sKey sz2 _) = sz1 == sz2
sameExceptExt (Blake2spKey sz1 _) (Blake2spKey sz2 _) = sz1 == sz2
sameExceptExt (SHA1Key _) (SHA1Key _) = True
sameExceptExt (MD5Key _) (MD5Key _) = True
sameExceptExt _ _ = False
{- Is the Key variety cryptographically secure, such that no two differing
- file contents can be mapped to the same Key? -}
cryptographicallySecure :: KeyVariety -> Bool
cryptographicallySecure (SHA2Key _ _) = True
cryptographicallySecure (SHA3Key _ _) = True
cryptographicallySecure (SKEINKey _ _) = True
cryptographicallySecure (Blake2bKey _ _) = True
cryptographicallySecure (Blake2sKey _ _) = True
cryptographicallySecure (Blake2spKey _ _) = True
cryptographicallySecure _ = False
{- Is the Key variety backed by a hash, which allows verifying content?
- It does not have to be cryptographically secure against eg birthday
- attacks.
-}
isVerifiable :: KeyVariety -> Bool
isVerifiable (SHA2Key _ _) = True
isVerifiable (SHA3Key _ _) = True
isVerifiable (SKEINKey _ _) = True
isVerifiable (Blake2bKey _ _) = True
isVerifiable (Blake2sKey _ _) = True
isVerifiable (Blake2spKey _ _) = True
isVerifiable (SHA1Key _) = True
isVerifiable (MD5Key _) = True
isVerifiable WORMKey = False
isVerifiable URLKey = False
isVerifiable (OtherKey _) = False
formatKeyVariety :: KeyVariety -> String
formatKeyVariety v = case v of
SHA2Key sz e -> adde e (addsz sz "SHA")
SHA3Key sz e -> adde e (addsz sz "SHA3_")
SKEINKey sz e -> adde e (addsz sz "SKEIN")
Blake2bKey sz e -> adde e (addsz sz "BLAKE2B")
Blake2sKey sz e -> adde e (addsz sz "BLAKE2S")
Blake2spKey sz e -> adde e (addsz sz "BLAKE2SP")
SHA1Key e -> adde e "SHA1"
MD5Key e -> adde e "MD5"
WORMKey -> "WORM"
URLKey -> "URL"
OtherKey s -> s
where
adde (HasExt False) s = s
adde (HasExt True) s = s ++ "E"
addsz (HashSize n) s = s ++ show n
parseKeyVariety :: String -> KeyVariety
parseKeyVariety "SHA256" = SHA2Key (HashSize 256) (HasExt False)
parseKeyVariety "SHA256E" = SHA2Key (HashSize 256) (HasExt True)
parseKeyVariety "SHA512" = SHA2Key (HashSize 512) (HasExt False)
parseKeyVariety "SHA512E" = SHA2Key (HashSize 512) (HasExt True)
parseKeyVariety "SHA224" = SHA2Key (HashSize 224) (HasExt False)
parseKeyVariety "SHA224E" = SHA2Key (HashSize 224) (HasExt True)
parseKeyVariety "SHA384" = SHA2Key (HashSize 384) (HasExt False)
parseKeyVariety "SHA384E" = SHA2Key (HashSize 384) (HasExt True)
parseKeyVariety "SHA3_512" = SHA3Key (HashSize 512) (HasExt False)
parseKeyVariety "SHA3_512E" = SHA3Key (HashSize 512) (HasExt True)
parseKeyVariety "SHA3_384" = SHA3Key (HashSize 384) (HasExt False)
parseKeyVariety "SHA3_384E" = SHA3Key (HashSize 384) (HasExt True)
parseKeyVariety "SHA3_256" = SHA3Key (HashSize 256) (HasExt False)
parseKeyVariety "SHA3_256E" = SHA3Key (HashSize 256) (HasExt True)
parseKeyVariety "SHA3_224" = SHA3Key (HashSize 224) (HasExt False)
parseKeyVariety "SHA3_224E" = SHA3Key (HashSize 224) (HasExt True)
parseKeyVariety "SKEIN512" = SKEINKey (HashSize 512) (HasExt False)
parseKeyVariety "SKEIN512E" = SKEINKey (HashSize 512) (HasExt True)
parseKeyVariety "SKEIN256" = SKEINKey (HashSize 256) (HasExt False)
parseKeyVariety "SKEIN256E" = SKEINKey (HashSize 256) (HasExt True)
#if MIN_VERSION_cryptonite(0,23,0)
parseKeyVariety "BLAKE2B160" = Blake2bKey (HashSize 160) (HasExt False)
parseKeyVariety "BLAKE2B160E" = Blake2bKey (HashSize 160) (HasExt True)
parseKeyVariety "BLAKE2B224" = Blake2bKey (HashSize 224) (HasExt False)
parseKeyVariety "BLAKE2B224E" = Blake2bKey (HashSize 224) (HasExt True)
parseKeyVariety "BLAKE2B256" = Blake2bKey (HashSize 256) (HasExt False)
parseKeyVariety "BLAKE2B256E" = Blake2bKey (HashSize 256) (HasExt True)
parseKeyVariety "BLAKE2B384" = Blake2bKey (HashSize 384) (HasExt False)
parseKeyVariety "BLAKE2B384E" = Blake2bKey (HashSize 384) (HasExt True)
parseKeyVariety "BLAKE2B512" = Blake2bKey (HashSize 512) (HasExt False)
parseKeyVariety "BLAKE2B512E" = Blake2bKey (HashSize 512) (HasExt True)
parseKeyVariety "BLAKE2S160" = Blake2sKey (HashSize 160) (HasExt False)
parseKeyVariety "BLAKE2S160E" = Blake2sKey (HashSize 160) (HasExt True)
parseKeyVariety "BLAKE2S224" = Blake2sKey (HashSize 224) (HasExt False)
parseKeyVariety "BLAKE2S224E" = Blake2sKey (HashSize 224) (HasExt True)
parseKeyVariety "BLAKE2S256" = Blake2sKey (HashSize 256) (HasExt False)
parseKeyVariety "BLAKE2S256E" = Blake2sKey (HashSize 256) (HasExt True)
parseKeyVariety "BLAKE2SP224" = Blake2spKey (HashSize 224) (HasExt False)
parseKeyVariety "BLAKE2SP224E" = Blake2spKey (HashSize 224) (HasExt True)
parseKeyVariety "BLAKE2SP256" = Blake2spKey (HashSize 256) (HasExt False)
parseKeyVariety "BLAKE2SP256E" = Blake2spKey (HashSize 256) (HasExt True)
#endif
parseKeyVariety "SHA1" = SHA1Key (HasExt False)
parseKeyVariety "SHA1E" = SHA1Key (HasExt True)
parseKeyVariety "MD5" = MD5Key (HasExt False)
parseKeyVariety "MD5E" = MD5Key (HasExt True)
parseKeyVariety "WORM" = WORMKey
parseKeyVariety "URL" = URLKey
parseKeyVariety s = OtherKey s