base58

commit b36e36e9dfbd793dec2908b3640394b8f47860db
parent 6cfa6b51774c195c6c637483593b08e3885eb352
Author: Jared Tobin <jared@jtobin.io>
Date:   Sat, 10 Oct 2026 15:24:32 +0400

lib: require a full checksum in base58check decode

Diffstat:
M
lib/Data/ByteString/Base58Check.hs
 | 
3
++-

1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/lib/Data/ByteString/Base58Check.hs b/lib/Data/ByteString/Base58Check.hs
@@ -40,7 +40,8 @@ decode :: BS.ByteString -> Maybe BS.ByteString
 decode mb = do
   bs <- B58.decode mb
   let len = BS.length bs
-      (pay, kek) = BS.splitAt (len - 4) bs
+  guard (len >= 4)
+  let (pay, kek) = BS.splitAt (len - 4) bs
       man = BS.take 4 (SHA256.hash (SHA256.hash pay))
   guard (kek == man)
   pure pay