Refactoring in Keccak code

2 files changed, 61 insertions, 86 deletions

diff --git a/crypto/src/pqc/crypto/hqc/HqcKeccakRandomGenerator.cs b/crypto/src/pqc/crypto/hqc/HqcKeccakRandomGenerator.cs
index 655abb82f..090f5a9c0 100644
--- a/crypto/src/pqc/crypto/hqc/HqcKeccakRandomGenerator.cs
+++ b/crypto/src/pqc/crypto/hqc/HqcKeccakRandomGenerator.cs
@@ -6,12 +6,15 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
 {
     internal class HqcKeccakRandomGenerator
     {
-        private static ulong[] KeccakRoundConstants = new ulong[]{0x0000000000000001L, 0x0000000000008082L,
-        0x800000000000808aL, 0x8000000080008000L, 0x000000000000808bL, 0x0000000080000001L, 0x8000000080008081L,
-        0x8000000000008009L, 0x000000000000008aL, 0x0000000000000088L, 0x0000000080008009L, 0x000000008000000aL,
-        0x000000008000808bL, 0x800000000000008bL, 0x8000000000008089L, 0x8000000000008003L, 0x8000000000008002L,
-        0x8000000000000080L, 0x000000000000800aL, 0x800000008000000aL, 0x8000000080008081L, 0x8000000000008080L,
-        0x0000000080000001L, 0x8000000080008008L};
+        private static readonly ulong[] KeccakRoundConstants =
+        {
+            0x0000000000000001L, 0x0000000000008082L, 0x800000000000808aL, 0x8000000080008000L,
+            0x000000000000808bL, 0x0000000080000001L, 0x8000000080008081L, 0x8000000000008009L,
+            0x000000000000008aL, 0x0000000000000088L, 0x0000000080008009L, 0x000000008000000aL,
+            0x000000008000808bL, 0x800000000000008bL, 0x8000000000008089L, 0x8000000000008003L,
+            0x8000000000008002L, 0x8000000000000080L, 0x000000000000800aL, 0x800000008000000aL,
+            0x8000000080008081L, 0x8000000000008080L, 0x0000000080000001L, 0x8000000080008008L
+        };
 
         protected long[] state = new long[26];
         protected byte[] dataQueue = new byte[192];
@@ -34,42 +37,41 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
         {
             switch (bitLength)
             {
-                case 128:
-                case 224:
-                case 256:
-                case 288:
-                case 384:
-                case 512:
-                    InitSponge(1600 - (bitLength << 1));
-                    break;
-                default:
-                    throw new ArgumentException("bitLength must be one of 128, 224, 256, 288, 384, or 512.");
+            case 128:
+            case 224:
+            case 256:
+            case 288:
+            case 384:
+            case 512:
+                InitSponge(1600 - (bitLength << 1));
+                break;
+            default:
+                throw new ArgumentException("bitLength must be one of 128, 224, 256, 288, 384, or 512.");
             }
         }
 
         private void InitSponge(int rate)
         {
             if ((rate <= 0) || (rate >= 1600) || ((rate % 64) != 0))
-            {
                 throw new InvalidOperationException("invalid rate value");
-            }
 
             this.rate = rate;
             for (int i = 0; i < state.Length; ++i)
             {
                 state[i] = 0L;
             }
-            Arrays.Fill(this.dataQueue, (byte)0);
+            Arrays.Fill(this.dataQueue, 0);
             this.bitsInQueue = 0;
             this.squeezing = false;
             this.fixedOutputLength = (1600 - rate) / 2;
         }
-        private void KeccakPermutation(long[] s)
+
+        private void KeccakPermutation()
         {
             long[] A = state;
 
-            long a00 = A[0], a01 = A[1], a02 = A[2], a03 = A[3], a04 = A[4];
-            long a05 = A[5], a06 = A[6], a07 = A[7], a08 = A[8], a09 = A[9];
+            long a00 = A[ 0], a01 = A[ 1], a02 = A[ 2], a03 = A[ 3], a04 = A[ 4];
+            long a05 = A[ 5], a06 = A[ 6], a07 = A[ 7], a08 = A[ 8], a09 = A[ 9];
             long a10 = A[10], a11 = A[11], a12 = A[12], a13 = A[13], a14 = A[14];
             long a15 = A[15], a16 = A[16], a17 = A[17], a18 = A[18], a19 = A[19];
             long a20 = A[20], a21 = A[21], a22 = A[22], a23 = A[23], a24 = A[24];
@@ -83,63 +85,43 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
                 long c3 = a03 ^ a08 ^ a13 ^ a18 ^ a23;
                 long c4 = a04 ^ a09 ^ a14 ^ a19 ^ a24;
 
-                long d1 = (c1 << 1 | Utils.UnsignedRightBitShiftLong(c1, -1)) ^ c4;
-                long d2 = (c2 << 1 | Utils.UnsignedRightBitShiftLong(c2, -1)) ^ c0;
-                long d3 = (c3 << 1 | Utils.UnsignedRightBitShiftLong(c3, -1)) ^ c1;
-                long d4 = (c4 << 1 | Utils.UnsignedRightBitShiftLong(c4, -1)) ^ c2;
-                long d0 = (c0 << 1 | Utils.UnsignedRightBitShiftLong(c0, -1)) ^ c3;
-
-                a00 ^= d1;
-                a05 ^= d1;
-                a10 ^= d1;
-                a15 ^= d1;
-                a20 ^= d1;
-                a01 ^= d2;
-                a06 ^= d2;
-                a11 ^= d2;
-                a16 ^= d2;
-                a21 ^= d2;
-                a02 ^= d3;
-                a07 ^= d3;
-                a12 ^= d3;
-                a17 ^= d3;
-                a22 ^= d3;
-                a03 ^= d4;
-                a08 ^= d4;
-                a13 ^= d4;
-                a18 ^= d4;
-                a23 ^= d4;
-                a04 ^= d0;
-                a09 ^= d0;
-                a14 ^= d0;
-                a19 ^= d0;
-                a24 ^= d0;
+                long d1 = Longs.RotateLeft(c1, 1) ^ c4;
+                long d2 = Longs.RotateLeft(c2, 1) ^ c0;
+                long d3 = Longs.RotateLeft(c3, 1) ^ c1;
+                long d4 = Longs.RotateLeft(c4, 1) ^ c2;
+                long d0 = Longs.RotateLeft(c0, 1) ^ c3;
+
+                a00 ^= d1; a05 ^= d1; a10 ^= d1; a15 ^= d1; a20 ^= d1;
+                a01 ^= d2; a06 ^= d2; a11 ^= d2; a16 ^= d2; a21 ^= d2;
+                a02 ^= d3; a07 ^= d3; a12 ^= d3; a17 ^= d3; a22 ^= d3;
+                a03 ^= d4; a08 ^= d4; a13 ^= d4; a18 ^= d4; a23 ^= d4;
+                a04 ^= d0; a09 ^= d0; a14 ^= d0; a19 ^= d0; a24 ^= d0;
 
                 // rho/pi
-                c1 = a01 << 1 | Utils.UnsignedRightBitShiftLong(a01, 63);
-                a01 = a06 << 44 | Utils.UnsignedRightBitShiftLong(a06, 20);
-                a06 = a09 << 20 | Utils.UnsignedRightBitShiftLong(a09, 44);
-                a09 = a22 << 61 | Utils.UnsignedRightBitShiftLong(a22, 3);
-                a22 = a14 << 39 | Utils.UnsignedRightBitShiftLong(a14, 25);
-                a14 = a20 << 18 |  Utils.UnsignedRightBitShiftLong(a20, 46);
-                a20 = a02 << 62 | Utils.UnsignedRightBitShiftLong(a02, 2);
-                a02 = a12 << 43 |  Utils.UnsignedRightBitShiftLong(a12, 21);
-                a12 = a13 << 25 |  Utils.UnsignedRightBitShiftLong(a13, 39);
-                a13 = a19 << 8 |  Utils.UnsignedRightBitShiftLong(a19, 56);
-                a19 = a23 << 56 |  Utils.UnsignedRightBitShiftLong(a23, 8);
-                a23 = a15 << 41 |  Utils.UnsignedRightBitShiftLong(a15, 23);
-                a15 = a04 << 27 | Utils.UnsignedRightBitShiftLong(a04, 37);
-                a04 = a24 << 14 |  Utils.UnsignedRightBitShiftLong(a24, 50);
-                a24 = a21 << 2 |  Utils.UnsignedRightBitShiftLong(a21, 62);
-                a21 = a08 << 55 | Utils.UnsignedRightBitShiftLong(a08, 9);
-                a08 = a16 << 45 |  Utils.UnsignedRightBitShiftLong(a16, 19);
-                a16 = a05 << 36 | Utils.UnsignedRightBitShiftLong(a05, 28);
-                a05 = a03 << 28 | Utils.UnsignedRightBitShiftLong(a03, 36);
-                a03 = a18 << 21 | Utils.UnsignedRightBitShiftLong(a18, 43);
-                a18 = a17 << 15 | Utils.UnsignedRightBitShiftLong(a17, 49);
-                a17 = a11 << 10 |  Utils.UnsignedRightBitShiftLong(a11, 54);
-                a11 = a07 << 6 | Utils.UnsignedRightBitShiftLong(a07, 58);
-                a07 = a10 << 3 | Utils.UnsignedRightBitShiftLong(a10, 61);
+                c1  = Longs.RotateLeft(a01,  1);
+                a01 = Longs.RotateLeft(a06, 44);
+                a06 = Longs.RotateLeft(a09, 20);
+                a09 = Longs.RotateLeft(a22, 61);
+                a22 = Longs.RotateLeft(a14, 39);
+                a14 = Longs.RotateLeft(a20, 18);
+                a20 = Longs.RotateLeft(a02, 62);
+                a02 = Longs.RotateLeft(a12, 43);
+                a12 = Longs.RotateLeft(a13, 25);
+                a13 = Longs.RotateLeft(a19,  8);
+                a19 = Longs.RotateLeft(a23, 56);
+                a23 = Longs.RotateLeft(a15, 41);
+                a15 = Longs.RotateLeft(a04, 27);
+                a04 = Longs.RotateLeft(a24, 14);
+                a24 = Longs.RotateLeft(a21,  2);
+                a21 = Longs.RotateLeft(a08, 55);
+                a08 = Longs.RotateLeft(a16, 45);
+                a16 = Longs.RotateLeft(a05, 36);
+                a05 = Longs.RotateLeft(a03, 28);
+                a03 = Longs.RotateLeft(a18, 21);
+                a18 = Longs.RotateLeft(a17, 15);
+                a17 = Longs.RotateLeft(a11, 10);
+                a11 = Longs.RotateLeft(a07,  6);
+                a07 = Longs.RotateLeft(a10,  3);
                 a10 = c1;
 
                 // chi
@@ -233,7 +215,7 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
                 inputLen -= (int) (rateBytes - state[25]);
                 count += (int) (rateBytes - state[25]);
                 state[25] = 0;
-                KeccakPermutation(state);
+                KeccakPermutation();
             }
 
             for (int i = 0; i < inputLen; i++)
@@ -271,7 +253,7 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
 
             while (outLen > 0)
             {
-                KeccakPermutation(state);
+                KeccakPermutation();
 
                 for (i = 0; i < outLen && i < rateBytes; i++)
                 {
diff --git a/crypto/src/pqc/crypto/hqc/Utils.cs b/crypto/src/pqc/crypto/hqc/Utils.cs
index bbd72b05b..4d44db07c 100644
--- a/crypto/src/pqc/crypto/hqc/Utils.cs
+++ b/crypto/src/pqc/crypto/hqc/Utils.cs
@@ -144,13 +144,6 @@ namespace Org.BouncyCastle.Pqc.Crypto.Hqc
             return a & 0xffff;
         }
 
-        internal static long UnsignedRightBitShiftLong(long a, int b)
-        {
-            ulong tmp = (ulong)a;
-            tmp >>= b;
-            return (long)tmp;
-        }
-
         internal static void XorULongToByte16Array(ushort[] output, int outOff, ulong input)
         {
             output[outOff + 0] ^= (ushort)input;