1 files changed, 49 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/params/DESedeParameters.java b/bcprov/src/main/java/org/bouncycastle/crypto/params/DESedeParameters.java
index 3a4bbfca..5b2d0d46 100644
--- a/bcprov/src/main/java/org/bouncycastle/crypto/params/DESedeParameters.java
+++ b/bcprov/src/main/java/org/bouncycastle/crypto/params/DESedeParameters.java
@@ -54,4 +54,53 @@ public class DESedeParameters
     {
         return isWeakKey(key, offset, key.length - offset);
     }
+
+    /**
+     * return true if the passed in key is a real 2/3 part DES-EDE key.
+     *
+     * @param key bytes making up the key
+     * @param offset offset into the byte array the key starts at
+     */
+    public static boolean isRealEDEKey(byte[] key, int offset)
+    {
+        return key.length == 16 ? isReal2Key(key, offset) : isReal3Key(key, offset);
+    }
+
+    /**
+     * return true if the passed in key is a real 2 part DES-EDE key.
+     *
+     * @param key bytes making up the key
+     * @param offset offset into the byte array the key starts at
+     */
+    public static boolean isReal2Key(byte[] key, int offset)
+    {
+        boolean isValid = false;
+        for (int i = offset; i != offset + 8; i++)
+        {
+            if (key[i] != key[i + 8])
+            {
+                isValid = true;
+            }
+        }
+
+        return isValid;
+    }
+
+    /**
+     * return true if the passed in key is a real 3 part DES-EDE key.
+     *
+     * @param key bytes making up the key
+     * @param offset offset into the byte array the key starts at
+     */
+    public static boolean isReal3Key(byte[] key, int offset)
+    {
+        boolean diff12 = false, diff13 = false, diff23 = false;
+        for (int i = offset; i != offset + 8; i++)
+        {
+            diff12 |= (key[i] != key[i + 8]);
+            diff13 |= (key[i] != key[i + 16]);
+            diff23 |= (key[i + 8] != key[i + 16]);
+        }
+        return diff12 && diff13 && diff23;
+    }
 }