[Cryptix-commits] projects/jce/src/cryptix.jce.provider.elgamal ElGamalCipher.java

[<gel...@mx...>]

gelderen    03/02/07 10:14:55

  Modified:    jce/src/cryptix.jce.provider.elgamal ElGamalCipher.java
  Log:
  Fix: Attempt to decrypt with wrong key can produce an
       ArrayIndexOutofBoundsException.
  
  Submitted-By: Kevin Dana <kd...@ag...>

Revision  Changes    Path
1.9       +21 -14    projects/jce/src/cryptix.jce.provider.elgamal/ElGamalCipher.java

Index: ElGamalCipher.java
===================================================================
RCS file: /home/cryptix-cvs/cvsroot/projects/jce/src/cryptix.jce.provider.elgamal/ElGamalCipher.java,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -r1.8 -r1.9
--- ElGamalCipher.java	15 Jan 2003 21:07:50 -0000	1.8
+++ ElGamalCipher.java	7 Feb 2003 15:14:55 -0000	1.9
@@ -1,4 +1,4 @@
-/* $Id: ElGamalCipher.java,v 1.8 2003/01/15 21:07:50 gelderen Exp $
+/* $Id: ElGamalCipher.java,v 1.9 2003/02/07 15:14:55 gelderen Exp $
  *
  * Copyright (C) 1995-2000 The Cryptix Foundation Limited.
  * All rights reserved.
@@ -42,7 +42,8 @@
  * Expirimental ElGamal implementation.
  *
  * @author Paul Waserbrot (pw...@cr...)
- * @version $Revision: 1.8 $
+ * @author Kevin Dana, Agorics Inc. (Agorics mod: 16273)
+ * @version $Revision: 1.9 $
  */
 public final class ElGamalCipher extends CipherSpi {
 
@@ -391,19 +392,25 @@
     throws BadPaddingException {
         int bt = input[inOffset + 1];
         int padLen = 1;
-        switch (bt) {
-          case 0x00:
-            for (;; padLen++)
-                if (input[inOffset + padLen + 1] != (byte)0x00) break;
-            break;
-          case 0x01:
-          case 0x02:
-            for (;; padLen++)
-                if (input[inOffset + padLen] == (byte)0x00) break;
-            break;
-          default:
-            throw new BadPaddingException("Wrong block type!");
+        try {
+            switch (bt) {
+              case 0x00:
+                for (;; padLen++)
+                    if (input[inOffset + padLen + 1] != (byte)0x00) break;
+                break;
+              case 0x01:
+              case 0x02:
+                for (;; padLen++)
+                    if (input[inOffset + padLen] == (byte)0x00) break;
+                break;
+              default:
+                throw new BadPaddingException("Wrong block type!");
+            }
+        } catch (ArrayIndexOutOfBoundsException ex) {
+            throw new BadPaddingException(
+                "Cannot unpad: padding incorrect for PKCS#1 block type "+bt);
         }
+
         padLen++;
 
         int len = inputLen - inOffset - padLen;