2 files changed, 39 insertions, 0 deletions

diff --git a/Arbitrary.patch b/Arbitrary.patch
index 9c753cb..6d855f1 100644
--- a/Arbitrary.patch
+++ b/Arbitrary.patch
@@ -10,6 +10,15 @@
                     1 -> do x1 <- arbitrary
                             x2 <- arbitrary
                             x3 <- arbitrary
+@@ -108,7 +107,7 @@
+                    6 -> return AES192
+                    7 -> return AES256
+                    8 -> return Twofish
+-                   9 -> do x1 <- arbitrary
++                   9 -> do x1 <- suchThat arbitrary (`notElem` [00,01,02,03,04,07,08,09,10])
+                            return (SymmetricAlgorithm x1)
+                    _ -> error "FATAL ERROR: Arbitrary instance, logic bug"
+
 @@ -116,7 +115,7 @@
 
  instance Arbitrary MPI where
diff --git a/Data/OpenPGP.hs b/Data/OpenPGP.hs
index acf5fb6..878fb99 100644
--- a/Data/OpenPGP.hs
+++ b/Data/OpenPGP.hs
@@ -46,6 +46,7 @@ module Data.OpenPGP (
         SignatureSubpacket(..),
         HashAlgorithm(..),
         KeyAlgorithm(..),
+        SymmetricAlgorithm(..),
         CompressionAlgorithm(..),
         MPI(..),
         find_key,
@@ -590,6 +591,35 @@ instance BINARY_CLASS KeyAlgorithm where
         put = put . enum_to_word8
         get = fmap enum_from_word8 get
 
+data SymmetricAlgorithm = Unencrypted | IDEA | TripleDES | CAST5 | Blowfish | AES128 | AES192 | AES256 | Twofish | SymmetricAlgorithm Word8
+        deriving (Show, Read, Eq)
+
+instance Enum SymmetricAlgorithm where
+        toEnum 00 = Unencrypted
+        toEnum 01 = IDEA
+        toEnum 02 = TripleDES
+        toEnum 03 = CAST5
+        toEnum 04 = Blowfish
+        toEnum 07 = AES128
+        toEnum 08 = AES192
+        toEnum 09 = AES256
+        toEnum 10 = Twofish
+        toEnum x  = SymmetricAlgorithm $ fromIntegral x
+        fromEnum Unencrypted = 00
+        fromEnum IDEA        = 01
+        fromEnum TripleDES   = 02
+        fromEnum CAST5       = 03
+        fromEnum Blowfish    = 04
+        fromEnum AES128      = 07
+        fromEnum AES192      = 08
+        fromEnum AES256      = 09
+        fromEnum Twofish     = 10
+        fromEnum (SymmetricAlgorithm x) = fromIntegral x
+
+instance BINARY_CLASS SymmetricAlgorithm where
+        put = put . enum_to_word8
+        get = fmap enum_from_word8 get
+
 data CompressionAlgorithm = Uncompressed | ZIP | ZLIB | BZip2 | CompressionAlgorithm Word8
         deriving (Show, Read, Eq)