1 files changed, 25 insertions, 21 deletions

diff --git a/Codec/Encryption/OpenPGP/ASCIIArmor/Decode.hs b/Codec/Encryption/OpenPGP/ASCIIArmor/Decode.hs
index e69087c..0376abc 100644
--- a/Codec/Encryption/OpenPGP/ASCIIArmor/Decode.hs
+++ b/Codec/Encryption/OpenPGP/ASCIIArmor/Decode.hs
@@ -26,17 +26,17 @@ import Data.Serialize.Put (runPut, putWord32be)
 import Data.String (IsString, fromString)
 import Data.Word (Word32)
 
-decode :: (Integral a, Read a, Show a, IsString e) => ByteString -> Either e ([Armor a])
+decode :: IsString e => ByteString -> Either e [Armor]
 decode bs = go (parse parseArmors bs)
     where
         go (Fail t c e) = Left (fromString e)
         go (Partial cont) = go (cont B.empty)
         go (Done _ r) = Right r
 
-parseArmors :: (Integral a, Read a, Show a) => Parser ([Armor a])
+parseArmors :: Parser [Armor]
 parseArmors = many parseArmor
 
-parseArmor :: (Integral a, Read a, Show a) => Parser (Armor a)
+parseArmor :: Parser Armor
 parseArmor = do
     atype <- prefixed beginLine <?> "begin line"
     headers <- armorHeaders <?> "headers"
@@ -45,23 +45,27 @@ parseArmor = do
     endLine atype <?> "end line"
     return $ Armor atype headers payload
 
-beginLine :: (Integral a, Read a, Show a) => Parser (ArmorType a)
+beginLine :: Parser ArmorType
 beginLine = do
-    string "-----BEGIN PGP "
-    atype <- message <|> pubkey <|> privkey<|> parts <|> signature
-    string "-----"
-    many (satisfy (inClass " \t"))
-    lineEnding
+    string "-----BEGIN PGP " <?> "leading minus-hyphens"
+    atype <- pubkey <|> privkey <|> parts <|> message <|> signature
+    string "-----" <?> "trailing minus-hyphens"
+    many (satisfy (inClass " \t")) <?> "whitespace"
+    lineEnding <?> "line ending"
     return atype
     where
-        message = string "MESSAGE" >> return ArmorMessage
-        pubkey = string "PUBLIC KEY BLOCK" >> return ArmorPublicKeyBlock
-        privkey = string "PRIVATE KEY BLOCK" >> return ArmorPrivateKeyBlock
-        signature = string "SIGNATURE" >> return ArmorSignature
-        parts = do
-            string "MESSAGE, PART "
-            firstnum <- read . BC8.unpack . B.pack <$> many1 (satisfy isDigit_w8)
-            return $ ArmorSplitMessageIndefinite firstnum
+        message = string "MESSAGE" *> return ArmorMessage
+        pubkey = string "PUBLIC KEY BLOCK" *> return ArmorPublicKeyBlock
+        privkey = string "PRIVATE KEY BLOCK" *> return ArmorPrivateKeyBlock
+        signature = string "SIGNATURE" *> return ArmorSignature
+        parts = string "MESSAGE, PART " *> (partsdef <|> partsindef)
+        partsdef = do
+            firstnum <- num
+            word8 (fromIntegral . fromEnum $ '/')
+            secondnum <- num
+            return $ ArmorSplitMessage (B.pack firstnum) (B.pack secondnum)
+        partsindef = ArmorSplitMessageIndefinite . B.pack <$> num
+        num = many1 (satisfy isDigit_w8) <?> "number"
 
 lineEnding :: Parser ByteString
 lineEnding = string "\n" <|> string "\r\n"
@@ -82,17 +86,17 @@ armorHeader = do
 blankishLine ::  Parser ByteString
 blankishLine = many (satisfy (inClass " \t")) >> lineEnding
 
-endLine :: (Integral a, Read a, Show a) => ArmorType a -> Parser ByteString
+endLine :: ArmorType -> Parser ByteString
 endLine atype = do
     string $ "-----END PGP " `B.append` aType atype `B.append` "-----"
     lineEnding
 
-aType :: (Integral a, Read a, Show a) => ArmorType a -> ByteString
+aType :: ArmorType -> ByteString
 aType (ArmorMessage) = BC8.pack "MESSAGE"
 aType (ArmorPublicKeyBlock) = BC8.pack "PUBLIC KEY BLOCK"
 aType (ArmorPrivateKeyBlock) = BC8.pack "PRIVATE KEY BLOCK"
-aType (ArmorSplitMessage x y) = BC8.pack $ "MESSAGE, PART " ++ show x ++ "/" ++ show y
-aType (ArmorSplitMessageIndefinite x) = BC8.pack $ "MESSAGE, PART " ++ show x
+aType (ArmorSplitMessage x y) = BC8.pack "MESSAGE, PART " `B.append` x `B.append` BC8.singleton '/' `B.append` y
+aType (ArmorSplitMessageIndefinite x) = BC8.pack "MESSAGE, PART " `B.append` x
 aType (ArmorSignature) = BC8.pack "SIGNATURE"
 
 base64Data :: Parser ByteString