Add multipartMerge

2 files changed, 26 insertions, 0 deletions

diff --git a/Codec/Encryption/OpenPGP/ASCIIArmor.hs b/Codec/Encryption/OpenPGP/ASCIIArmor.hs
index 26d58dd..6d0c172 100644
--- a/Codec/Encryption/OpenPGP/ASCIIArmor.hs
+++ b/Codec/Encryption/OpenPGP/ASCIIArmor.hs
@@ -7,7 +7,9 @@ module Codec.Encryption.OpenPGP.ASCIIArmor (
    encode
  , decode
  , parseArmor
+ , multipartMerge
 ) where
 
 import Codec.Encryption.OpenPGP.ASCIIArmor.Encode (encode)
 import Codec.Encryption.OpenPGP.ASCIIArmor.Decode (decode, parseArmor)
+import Codec.Encryption.OpenPGP.ASCIIArmor.Multipart (multipartMerge)
diff --git a/Codec/Encryption/OpenPGP/ASCIIArmor/Multipart.hs b/Codec/Encryption/OpenPGP/ASCIIArmor/Multipart.hs
new file mode 100644
index 0000000..8719c7c
--- /dev/null
+++ b/Codec/Encryption/OpenPGP/ASCIIArmor/Multipart.hs
@@ -0,0 +1,24 @@
+-- ASCIIArmor/Multipart.hs: OpenPGP (RFC4880) ASCII armor implementation
+-- Copyright Ⓒ 2012  Clint Adams
+-- This software is released under the terms of the ISC license.
+-- (See the LICENSE file).
+
+module Codec.Encryption.OpenPGP.ASCIIArmor.Multipart (
+   multipartMerge
+) where
+
+import Codec.Encryption.OpenPGP.ASCIIArmor.Types
+
+import Data.ByteString (ByteString)
+import qualified Data.ByteString as B
+
+multipartMerge :: [Armor] -> Armor
+multipartMerge as = go as (Armor ArmorMessage [] B.empty)
+    where
+        go :: [Armor] -> Armor -> Armor
+        go [] state = state
+        go ((Armor at hs bs):as) state = go as (go' at hs bs state)
+        go' :: ArmorType -> [(String,String)] -> ByteString -> Armor -> Armor
+        go' (ArmorSplitMessage _ _) hs bs (Armor _ ohs obs) = Armor ArmorMessage (ohs ++ hs) (obs `B.append` bs)
+        go' (ArmorSplitMessageIndefinite _) hs bs (Armor _ ohs obs) = Armor ArmorMessage (ohs ++ hs) (obs `B.append` bs)
+        go' _ _ _ state = state