1 files changed, 52 insertions, 0 deletions

diff --git a/KnownHosts.hs b/KnownHosts.hs
new file mode 100644
index 0000000..a8f4fe3
--- /dev/null
+++ b/KnownHosts.hs
@@ -0,0 +1,52 @@
+{-# LANGUAGE OverloadedStrings #-}
+module KnownHosts where
+
+import qualified Data.ByteString.Lazy.Char8 as L
+import Data.Char
+import Data.List
+import qualified SSHKey as SSH
+
+data KnownHostsEntry = KnownHostsEntry
+    { eLineno :: Int
+    , eSp :: [L.ByteString]
+    , eComment :: L.ByteString
+    , eKeyBlob :: L.ByteString
+    , eKeyHeader :: L.ByteString
+    , eHosts :: [L.ByteString]
+    }
+ deriving (Eq,Show)
+
+serializeLine :: KnownHostsEntry -> L.ByteString
+serializeLine (KnownHostsEntry { eSp = sp
+                               , eComment = comment
+                               , eKeyHeader = hdr
+                               , eKeyBlob = key
+                               , eHosts = hosts
+                               })
+    = L.concat $ zipWith L.append [host,hdr,key] (take 3 sp) ++ [comment]
+ where
+    host = L.intercalate "," hosts
+    
+
+parseLine :: Int -> L.ByteString -> KnownHostsEntry
+parseLine num str = KnownHostsEntry
+    { eLineno = num
+    , eSp = sp
+    , eComment = comment
+    , eKeyHeader = hdr
+    , eKeyBlob = key
+    , eHosts = hosts
+    }
+ where
+    gs = L.groupBy (\a b -> isSpace a==isSpace b) str
+    (sp,ns) = partition (\x -> isSpace (L.head x)) gs
+    hosts = do
+        h <- take 1 ns
+        let hs = L.groupBy (\_ b -> b/=',') h
+            hs' = map L.tail $ drop 1 hs
+        h0 <- take 1 hs
+        h0 : hs'
+    hdr = L.concat $ take 1 (drop 1 ns)
+    key = L.concat $ take 1 (drop 2 ns)
+    comment = L.concat $ zipWith L.append (drop 3 ns) (drop 3 sp ++ repeat "")
+