Refactor on PhotonBeetleEngine and PhotonBeetleDigest

Author: gefeili

core/src/main/java/org/bouncycastle/crypto/digests/PhotonBeetleDigest.java

@@ -17,11 +17,15 @@ public class PhotonBeetleDigest
     public static class Friend
     {
         private static final Friend INSTANCE = new Friend();
-        private Friend() {}
+
+        private Friend()
+        {
+        }
     }
+
     private final byte[] state;
     private final byte[][] state_2d;
-    private final int STATE_INBYTES = 32;
+    private static final int STATE_INBYTES = 32;
     private static final int D = 8;
     private int blockCount;
 
@@ -45,7 +49,7 @@ protected void processBytes(byte[] input, int inOff)
         else
         {
             PhotonBeetleEngine.PhotonPermutation(Friend.INSTANCE, state_2d, state);
-            Bytes.xorTo(BlockSize, input, inOff, state, 0);
+            Bytes.xorTo(BlockSize, input, inOff, state);
         }
         blockCount++;
     }
@@ -71,7 +75,7 @@ else if (blockCount == 4 && m_bufPos == 0)
         else
         {
             PhotonBeetleEngine.PhotonPermutation(Friend.INSTANCE, state_2d, state);
-            Bytes.xorTo(m_bufPos, m_buf, 0, state, 0);
+            Bytes.xorTo(m_bufPos, m_buf, state);
             if (m_bufPos < BlockSize)
             {
                 state[m_bufPos] ^= 0x01; // ozs

core/src/main/java/org/bouncycastle/crypto/engines/PhotonBeetleEngine.java

@@ -1,6 +1,7 @@
 package org.bouncycastle.crypto.engines;
 
 import org.bouncycastle.crypto.digests.PhotonBeetleDigest;
+import org.bouncycastle.util.Bytes;
 
 /**
  * Photon-Beetle, <a href="https://www.isical.ac.in/~lightweight/beetle/"></a>
@@ -96,7 +97,7 @@ protected void init(byte[] key, byte[] iv)
     protected void processBufferAAD(byte[] input, int inOff)
     {
         PhotonPermutation(state_2d, state);
-        XOR(input, inOff, BlockSize);
+        Bytes.xorTo(BlockSize, input, inOff, state);
     }
 
     public void processFinalAAD()
@@ -109,7 +110,7 @@ public void processFinalAAD()
                 if (m_aadPos != 0)
                 {
                     PhotonPermutation(state_2d, state);
-                    XOR(m_aad, 0, m_aadPos);
+                    Bytes.xorTo(m_aadPos, m_aad, state);
                     if (m_aadPos < BlockSize)
                     {
                         state[m_aadPos] ^= 0x01; // ozs
@@ -127,14 +128,14 @@ protected void processBufferEncrypt(byte[] input, int inOff, byte[] output, int
     {
         PhotonPermutation(state_2d, state);
         rhoohr(output, outOff, input, inOff, BlockSize);
-        XOR(input, inOff, BlockSize);
+        Bytes.xorTo(BlockSize, input, inOff, state);
     }
 
     protected void processBufferDecrypt(byte[] input, int inOff, byte[] output, int outOff)
     {
         PhotonPermutation(state_2d, state);
         rhoohr(output, outOff, input, inOff, BlockSize);
-        XOR(output, outOff, BlockSize);
+        Bytes.xorTo(BlockSize, output, outOff, state);
     }
 
     @Override
@@ -157,11 +158,11 @@ protected void processFinalBlock(byte[] output, int outOff)
                 rhoohr(output, outOff, m_buf, 0, bufferLen);
                 if (forEncryption)
                 {
-                    XOR(m_buf, 0, bufferLen);
+                    Bytes.xorTo(bufferLen, m_buf, state);
                 }
                 else
                 {
-                    XOR(output, outOff, bufferLen);
+                    Bytes.xorTo(bufferLen, output, outOff, state);
                 }
                 if (bufferLen < BlockSize)
                 {
@@ -297,14 +298,6 @@ private void rhoohr(byte[] ciphertext, int outOff, byte[] plaintext, int inOff,
         }
     }
 
-    private void XOR(byte[] in_right, int rOff, int iolen_inbytes)
-    {
-        for (int i = 0; i < iolen_inbytes; i++)
-        {
-            state[i] ^= in_right[rOff++];
-        }
-    }
-
     public static void PhotonPermutation(PhotonBeetleDigest.Friend friend, byte[][] state_2d, byte[] state)
     {
         if (null == friend)

core/src/main/java/org/bouncycastle/util/Bytes.java

@@ -32,6 +32,14 @@ public static void xorTo(int len, byte[] x, byte[] z)
         }
     }
 
+    public static void xorTo(int len, byte[] x, int xOff, byte[] z)
+    {
+        for (int i = 0; i < len; ++i)
+        {
+            z[i] ^= x[xOff++];
+        }
+    }
+
     public static void xorTo(int len, byte[] x, int xOff, byte[] z, int zOff)
     {
         for (int i = 0; i < len; ++i)