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authorJoey Hess <joeyh@joeyh.name>2016-08-10 12:16:44 -0400
committerJoey Hess <joeyh@joeyh.name>2016-08-10 12:16:44 -0400
commit90b7c385f4e2f293502f9aca38aaa041b7b2f486 (patch)
tree5cc2d68b41406081d9c52271af5852ab148d1ba6 /Types.hs
parent730c54a40681776aaaab1b727af42559cf1592fe (diff)
downloadkeysafe-90b7c385f4e2f293502f9aca38aaa041b7b2f486.tar.gz
types for new version storage scheme
Diffstat (limited to 'Types.hs')
-rw-r--r--Types.hs81
1 files changed, 4 insertions, 77 deletions
diff --git a/Types.hs b/Types.hs
index 41c3a00..7262f33 100644
--- a/Types.hs
+++ b/Types.hs
@@ -6,94 +6,21 @@ import Types.Cost
import Entropy
import qualified Data.ByteString as B
import qualified Data.ByteString.Lazy as BL
-import qualified Crypto.Argon2 as Argon2
import Data.String
-- | keysafe stores secret keys.
newtype SecretKey = SecretKey B.ByteString
--- | Objects stored on a keysafe server are (probably) a shard of an
--- encrypted secret key.
-newtype StorableObject = StorableObject { fromStorableObject :: BL.ByteString }
-
--- | Parameters for sharding. The secret is split into
--- N objects, such that only M are needed to reconstruct it.
-data ShardParams = ShardParams
- { totalObjects :: Int -- ^ N
- , neededObjects :: Int -- ^ M
- }
-
--- | keysafe stores data for a long time, and needs to be able to process
--- data from a long time ago when restoring a key. We don't want to be
--- locked into old choices of crypto primitives etc forever.
---
--- So, every parameter that can be tuned is configured in this data
--- structure. Carefully chosen parts of this are exposed at various points
--- in the data stored for a key, to allow future versions of keysafe to
--- make the right decisions when processing it.
-data Tunables = Tunables
- { shardParams :: ShardParams
- , objectSize :: Int
- -- ^ a StorableObject is exactly this many bytes in size
- , expensiveHashTunable :: ExpensiveHashTunable
- , encryptionTunable :: EncryptionTunable
- , decryptionPuzzleTunable :: DecryptionPuzzleTunable
- }
-
--- | An expensive hash, used to make it hard to crack an encrypted secret key.
-data ExpensiveHashTunable = UseArgon2 Argon2.HashOptions (Cost CreationOp)
- deriving (Show)
-
--- | What encryption to use.
-data EncryptionTunable = UseAES256
- deriving (Show)
-
--- | An additional puzzle that makes decryption more expensive.
-data DecryptionPuzzleTunable = KeyBlindingLeftSide (Cost DecryptionOp)
- deriving (Show)
-
-defaultTunables :: Tunables
-defaultTunables = Tunables
- { shardParams = ShardParams { totalObjects = 3, neededObjects = 2 }
- , objectSize = 1024*64 -- 64 kb
- , expensiveHashTunable = UseArgon2 argonoptions argoncost
- , encryptionTunable = UseAES256
- -- AES can be calculated more efficiently by a GPU, so the
- -- cost is a GPU cost.
- -- This is set to only 1 minute because GPUs are quite a lot
- -- faster than CPUs at AES, and so setting it higher would make
- -- clients too slow at key recovery.
- , decryptionPuzzleTunable = KeyBlindingLeftSide (GPUCost (Seconds 60))
- }
- where
- argonoptions = Argon2.HashOptions
- { Argon2.hashIterations = 10000
- , Argon2.hashMemory = 131072 -- 128 mebibtyes per thread
- , Argon2.hashParallelism = 4 -- 4 threads
- , Argon2.hashVariant = Argon2.Argon2i
- }
- -- argon2 is GPU and ASIC resistent, so it uses CPU time.
- -- The above HashOptions were benchmarked at 661 seconds CPU time
- -- on a 2 core Intel(R) Core(TM) i5-4210Y CPU @ 1.50GHz.
- -- Since cost is measured per core, we double that.
- argoncost = CPUCost (Seconds (2*600))
-
--- | Dials back cryptographic difficulty, not for production use.
-testModeTunables :: Tunables
-testModeTunables = Tunables
- { shardParams = ShardParams { totalObjects = 3, neededObjects = 2 }
- , objectSize = 1024*64
- , expensiveHashTunable = UseArgon2 Argon2.defaultHashOptions (CPUCost (Seconds (2*600)))
- , encryptionTunable = UseAES256
- , decryptionPuzzleTunable = KeyBlindingLeftSide (GPUCost (Seconds 60))
- }
-
-- | The secret key, encrypted with a password.
data EncryptedSecretKey = EncryptedSecretKey B.ByteString (CostCalc BruteForceOp UnknownPassword)
instance Bruteforceable EncryptedSecretKey UnknownPassword where
getBruteCostCalc (EncryptedSecretKey _ cc) = cc
+-- | Objects stored on a keysafe server are (probably) a shard of an
+-- encrypted secret key.
+newtype StorableObject = StorableObject { fromStorableObject :: BL.ByteString }
+
-- | A password used to encrypt a key stored in keysafe.
newtype Password = Password B.ByteString
deriving (IsString)