diff --git a/src/ssn/extractFileStream.ts b/src/ssn/extractFileStream.ts
index ca7899d..8b6689b 100644
--- a/src/ssn/extractFileStream.ts
+++ b/src/ssn/extractFileStream.ts
@@ -31,13 +31,14 @@ export default function extractFileStream(file: ISsnFileEntry, inputStream: stre
 
   let curStream = inputStream;
 
-  //set max length
-  const maxLength = streamSetMaxLength(curStream, 12 + file.compressedSize);
+  const storedSize = (file.decryptionKeys !== undefined) ? (12 + file.compressedSize) : file.compressedSize;
+  //set max length (including random 12 byte encryption header)
+  const maxLength = streamSetMaxLength(curStream, storedSize);
   curStream = maxLength;
 
   //pipe into decryption if file is encrypted
   if (file.decryptionKeys !== undefined) {
-    const decryptTransform = decryptStream(curStream, file.decryptionKeys);
+    const decryptTransform = decryptStream(curStream, [...file.decryptionKeys] as [number, number, number]);
     curStream = decryptTransform;
   }