1 files changed, 111 insertions, 6 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/crypto/modes/gcm/GCMUtil.java b/bcprov/src/main/java/org/bouncycastle/crypto/modes/gcm/GCMUtil.java
index ce02be4..4875301 100644
--- a/bcprov/src/main/java/org/bouncycastle/crypto/modes/gcm/GCMUtil.java
+++ b/bcprov/src/main/java/org/bouncycastle/crypto/modes/gcm/GCMUtil.java
@@ -19,14 +19,23 @@ abstract class GCMUtil
         return tmp;
     }
 
+    static byte[] asBytes(int[] ns)
+    {
+        byte[] output = new byte[16];
+        Pack.intToBigEndian(ns, output, 0);
+        return output;
+    }
+
     static int[] asInts(byte[] bs)
     {
-        int[] us = new int[4];
-        us[0] = Pack.bigEndianToInt(bs, 0);
-        us[1] = Pack.bigEndianToInt(bs, 4);
-        us[2] = Pack.bigEndianToInt(bs, 8);
-        us[3] = Pack.bigEndianToInt(bs, 12);
-        return us;
+        int[] output = new int[4];
+        Pack.bigEndianToInt(bs, 0, output);
+        return output;
+    }
+
+    static void asInts(byte[] bs, int[] output)
+    {
+        Pack.bigEndianToInt(bs, 0, output);
     }
 
     static void multiply(byte[] block, byte[] val)
@@ -71,6 +80,17 @@ abstract class GCMUtil
         }
     }
 
+    static void multiplyP(int[] x, int[] output)
+    {
+        boolean lsb = (x[3] & 1) != 0;
+        shiftRight(x, output);
+        if (lsb)
+        {
+            output[0] ^= 0xe1000000;
+        }
+    }
+
+    // P is the value with only bit i=1 set
     static void multiplyP8(int[] x)
     {
 //        for (int i = 8; i != 0; --i)
@@ -89,6 +109,19 @@ abstract class GCMUtil
         }
     }
 
+    static void multiplyP8(int[] x, int[] output)
+    {
+        int lsw = x[3];
+        shiftRightN(x, 8, output);
+        for (int i = 7; i >= 0; --i)
+        {
+            if ((lsw & (1 << i)) != 0)
+            {
+                output[0] ^= (0xe1000000 >>> (7 - i));
+            }
+        }
+    }
+
     static void shiftRight(byte[] block)
     {
         int i = 0;
@@ -105,6 +138,22 @@ abstract class GCMUtil
         }
     }
 
+    static void shiftRight(byte[] block, byte[] output)
+    {
+        int i = 0;
+        int bit = 0;
+        for (;;)
+        {
+            int b = block[i] & 0xff;
+            output[i] = (byte) ((b >>> 1) | bit);
+            if (++i == 16)
+            {
+                break;
+            }
+            bit = (b & 1) << 7;
+        }
+    }
+
     static void shiftRight(int[] block)
     {
         int i = 0;
@@ -121,6 +170,22 @@ abstract class GCMUtil
         }
     }
 
+    static void shiftRight(int[] block, int[] output)
+    {
+        int i = 0;
+        int bit = 0;
+        for (;;)
+        {
+            int b = block[i];
+            output[i] = (b >>> 1) | bit;
+            if (++i == 4)
+            {
+                break;
+            }
+            bit = b << 31;
+        }
+    }
+
     static void shiftRightN(int[] block, int n)
     {
         int i = 0;
@@ -137,6 +202,22 @@ abstract class GCMUtil
         }
     }
 
+    static void shiftRightN(int[] block, int n, int[] output)
+    {
+        int i = 0;
+        int bits = 0;
+        for (;;)
+        {
+            int b = block[i];
+            output[i] = (b >>> n) | bits;
+            if (++i == 4)
+            {
+                break;
+            }
+            bits = b << (32 - n);
+        }
+    }
+
     static void xor(byte[] block, byte[] val)
     {
         for (int i = 15; i >= 0; --i)
@@ -145,6 +226,22 @@ abstract class GCMUtil
         }
     }
 
+    static void xor(byte[] block, byte[] val, int off, int len)
+    {
+        while (len-- > 0)
+        {
+            block[len] ^= val[off + len];
+        }
+    }
+
+    static void xor(byte[] block, byte[] val, byte[] output)
+    {
+        for (int i = 15; i >= 0; --i)
+        {
+            output[i] = (byte)(block[i] ^ val[i]);
+        }
+    }
+
     static void xor(int[] block, int[] val)
     {
         for (int i = 3; i >= 0; --i)
@@ -152,4 +249,12 @@ abstract class GCMUtil
             block[i] ^= val[i];
         }
     }
+
+    static void xor(int[] block, int[] val, int[] output)
+    {
+        for (int i = 3; i >= 0; --i)
+        {
+            output[i] = block[i] ^ val[i];
+        }
+    }
 }