git-annex/Types/Backend.hs
Joey Hess cc17ac423b
implement isCryptographicallySecureKey for VURL
Considerable difficulty to work around an import cycle. Had to move the
list of backends (except for VURL) to Backend.Variety to VURL could use
it.

Sponsored-by: Kevin Mueller on Patreon
2024-02-29 17:26:35 -04:00

47 lines
1.7 KiB
Haskell

{- git-annex key backend data type
-
- Most things should not need this, using Types instead
-
- Copyright 2010-2024 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU AGPL version 3 or higher.
-}
module Types.Backend where
import Types.Key
import Types.KeySource
import Utility.Metered
import Utility.FileSystemEncoding
import Utility.Hash (IncrementalVerifier)
data BackendA a = Backend
{ backendVariety :: KeyVariety
, genKey :: Maybe (KeySource -> MeterUpdate -> a Key)
-- Verifies the content of a key, stored in a file, using a hash.
-- This does not need to be cryptographically secure.
, verifyKeyContent :: Maybe (Key -> RawFilePath -> a Bool)
-- Incrementally verifies the content of a key, using the same
-- hash as verifyKeyContent, but with the content provided
-- incrementally a piece at a time, until finalized.
, verifyKeyContentIncrementally :: Maybe (Key -> a IncrementalVerifier)
-- Checks if a key can be upgraded to a better form.
, canUpgradeKey :: Maybe (Key -> Bool)
-- Checks if there is a fast way to migrate a key to a different
-- backend (ie, without re-hashing).
, fastMigrate :: Maybe (Key -> BackendA a -> AssociatedFile -> a (Maybe Key))
-- Checks if a key is known (or assumed) to always refer to the
-- same data.
, isStableKey :: Key -> Bool
-- Are all keys using this backend verified using a cryptographically
-- secure hash?
, isCryptographicallySecure :: Bool
-- Checks if a key is verified using a cryptographically secure hash.
, isCryptographicallySecureKey :: Key -> a Bool
}
instance Show (BackendA a) where
show backend = "Backend { name =\"" ++ decodeBS (formatKeyVariety (backendVariety backend)) ++ "\" }"
instance Eq (BackendA a) where
a == b = backendVariety a == backendVariety b