add encryption support

git-svn-id: https://svn.apache.org/repos/asf/poi/branches/hssf_cryptoapi@1756964 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 19 insertions, 10 deletions

diff --git a/src/java/org/apache/poi/poifs/crypt/ChunkedCipherInputStream.java b/src/java/org/apache/poi/poifs/crypt/ChunkedCipherInputStream.java
index 7b5632dea7..e59ceb369c 100644
--- a/src/java/org/apache/poi/poifs/crypt/ChunkedCipherInputStream.java
+++ b/src/java/org/apache/poi/poifs/crypt/ChunkedCipherInputStream.java
@@ -222,24 +222,33 @@ public abstract class ChunkedCipherInputStream extends LittleEndianInputStream {
     /**

      * Used when BIFF header fields (sid, size) are being read. The internal

      * {@link Cipher} instance must step even when unencrypted bytes are read

+     * 

      */

-    public int readPlain(byte b[], int off, int len) throws IOException {

+    @Override

+    public void readPlain(byte b[], int off, int len) {

         if (len <= 0) {

-            return len;

+            return;

         }

 

-        int readBytes, total = 0;

-        do {

-            readBytes = read(b, off, len, true);

-            total += Math.max(0, readBytes);

-        } while (readBytes > -1 && total < len);

-

-        return total;

+        try {

+            int readBytes, total = 0;

+            do {

+                readBytes = read(b, off, len, true);

+                total += Math.max(0, readBytes);

+            } while (readBytes > -1 && total < len);

+    

+            if (total < len) {

+                throw new EOFException("buffer underrun");

+            }

+        } catch (IOException e) {

+            // need to wrap checked exception, because of LittleEndianInput interface :(

+            throw new RuntimeException(e);

+        }

     }

 

     /**

      * Some ciphers (actually just XOR) are based on the record size,

-     * which needs to be set before encryption

+     * which needs to be set before decryption

      *

      * @param recordSize the size of the next record

      */