randomS2K utility.

2 files changed, 15 insertions, 0 deletions

diff --git a/Data/OpenPGP/Util.hs b/Data/OpenPGP/Util.hs
index 19d98ec..6b1ebb1 100644
--- a/Data/OpenPGP/Util.hs
+++ b/Data/OpenPGP/Util.hs
@@ -6,6 +6,7 @@ module Data.OpenPGP.Util
     , pgpSign
     , GenerateKeyParams(..)
     , generateKey
+    , randomS2K
     ) where
 
 import Data.OpenPGP.Util.Fingerprint
diff --git a/Data/OpenPGP/Util/DecryptSecretKey.hs b/Data/OpenPGP/Util/DecryptSecretKey.hs
index 1c519ae..1188f3e 100644
--- a/Data/OpenPGP/Util/DecryptSecretKey.hs
+++ b/Data/OpenPGP/Util/DecryptSecretKey.hs
@@ -4,6 +4,7 @@
 module Data.OpenPGP.Util.DecryptSecretKey where
 
 import qualified Data.OpenPGP as OpenPGP
+import Data.OpenPGP.Internal (decode_s2k_count)
 import qualified Data.ByteString as BS
 import qualified Data.ByteString.Lazy as LZ
 import Data.Word (Word16)
@@ -19,6 +20,7 @@ import Data.Binary.Get (runGet)
 #endif
 import Control.Exception as Exception (IOException(..),catch)
 import Data.Binary.Put (runPut)
+import qualified Data.Serialize as Cereal
 import Control.Applicative ( (<$>) )
 
 import qualified Crypto.Cipher.AES as Vincent
@@ -231,3 +233,15 @@ encryptSecretKey passphrase s2k salgo plain = do
 
 
     -- k = string2key s2k passphrase -- OpenPGP.string2key hashBySymbol s2k passphrase
+
+randomS2K :: OpenPGP.HashAlgorithm -> IO OpenPGP.S2K
+randomS2K hash = do
+    g <- makeGen Nothing
+#if defined(VERSION_cryptonite)
+    let (saltbs,g') = Vincent.randomBytesGenerate 9 g
+#else
+    let (saltbs,g') = Vincent.cprgGenerate 9 g
+#endif
+    let Right salt = Cereal.decode (BS.drop 1 saltbs)
+    return $ OpenPGP.IteratedSaltedS2K hash salt (decode_s2k_count $ BS.head saltbs)
+