Refactoring in Sparkle

2 files changed, 48 insertions, 44 deletions

diff --git a/crypto/src/crypto/digests/SparkleDigest.cs b/crypto/src/crypto/digests/SparkleDigest.cs
index df51c9935..f818f0257 100644
--- a/crypto/src/crypto/digests/SparkleDigest.cs
+++ b/crypto/src/crypto/digests/SparkleDigest.cs
@@ -24,12 +24,8 @@ namespace Org.BouncyCastle.Crypto.Digests
             ESCH384
         }
 
-        private const int RATE_BITS = 128;
         private const int RATE_BYTES = 16;
-        private const int RATE_UINTS = 4;
-
-        private static readonly uint[] RCON = { 0xB7E15162U, 0xBF715880U, 0x38B4DA56U, 0x324E7738U, 0xBB1185EBU,
-            0x4F7C7B57U, 0xCFBFA1C8U, 0xC2B3293DU };
+        private const int RATE_WORDS = 4;
 
         private string algorithmName;
         private readonly uint[] state;
@@ -37,7 +33,7 @@ namespace Org.BouncyCastle.Crypto.Digests
         private readonly int DIGEST_BYTES;
         private readonly int SPARKLE_STEPS_SLIM;
         private readonly int SPARKLE_STEPS_BIG;
-        private readonly int STATE_UINTS;
+        private readonly int STATE_WORDS;
 
         private int m_bufPos = 0;
 
@@ -50,20 +46,20 @@ namespace Org.BouncyCastle.Crypto.Digests
                 DIGEST_BYTES = 32;
                 SPARKLE_STEPS_SLIM = 7;
                 SPARKLE_STEPS_BIG = 11;
-                STATE_UINTS = 12;
+                STATE_WORDS = 12;
                 break;
             case SparkleParameters.ESCH384:
                 algorithmName = "ESCH-384";
                 DIGEST_BYTES = 48;
                 SPARKLE_STEPS_SLIM = 8;
                 SPARKLE_STEPS_BIG = 12;
-                STATE_UINTS = 16;
+                STATE_WORDS = 16;
                 break;
             default:
                 throw new ArgumentException("Invalid definition of ESCH instance");
             }
 
-            state = new uint[STATE_UINTS];
+            state = new uint[STATE_WORDS];
         }
 
         public string AlgorithmName => algorithmName;
@@ -165,7 +161,7 @@ namespace Org.BouncyCastle.Crypto.Digests
             // addition of constant M1 or M2 to the state
             if (m_bufPos < RATE_BYTES)
             {
-                state[(STATE_UINTS >> 1) - 1] ^= 1U << 24;
+                state[(STATE_WORDS >> 1) - 1] ^= 1U << 24;
 
                 // padding
                 m_buf[m_bufPos] = 0x80;
@@ -176,25 +172,24 @@ namespace Org.BouncyCastle.Crypto.Digests
             }
             else
             {
-                state[(STATE_UINTS >> 1) - 1] ^= 1U << 25;
+                state[(STATE_WORDS >> 1) - 1] ^= 1U << 25;
             }
 
-            // addition of last msg block (incl. padding)
             ProcessBlock(m_buf, 0, SPARKLE_STEPS_BIG);
 
-            Pack.UInt32_To_LE(state, 0, RATE_UINTS, output, outOff);
+            Pack.UInt32_To_LE(state, 0, RATE_WORDS, output, outOff);
 
-            if (STATE_UINTS == 16)
+            if (STATE_WORDS == 16)
             {
                 SparkleEngine.SparkleOpt16(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state, 0, RATE_UINTS, output, outOff + 16);
+                Pack.UInt32_To_LE(state, 0, RATE_WORDS, output, outOff + 16);
                 SparkleEngine.SparkleOpt16(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state, 0, RATE_UINTS, output, outOff + 32);
+                Pack.UInt32_To_LE(state, 0, RATE_WORDS, output, outOff + 32);
             }
             else
             {
                 SparkleEngine.SparkleOpt12(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state, 0, RATE_UINTS, output, outOff + 16);
+                Pack.UInt32_To_LE(state, 0, RATE_WORDS, output, outOff + 16);
             }
 
             Reset();
@@ -208,7 +203,7 @@ namespace Org.BouncyCastle.Crypto.Digests
             // addition of constant M1 or M2 to the state
             if (m_bufPos < RATE_BYTES)
             {
-                state[(STATE_UINTS >> 1) - 1] ^= 1U << 24;
+                state[(STATE_WORDS >> 1) - 1] ^= 1U << 24;
 
                 // padding
                 m_buf[m_bufPos] = 0x80;
@@ -219,25 +214,25 @@ namespace Org.BouncyCastle.Crypto.Digests
             }
             else
             {
-                state[(STATE_UINTS >> 1) - 1] ^= 1U << 25;
+                state[(STATE_WORDS >> 1) - 1] ^= 1U << 25;
             }
 
             // addition of last msg block (incl. padding)
             ProcessBlock(m_buf, SPARKLE_STEPS_BIG);
 
-            Pack.UInt32_To_LE(state[..RATE_UINTS], output);
+            Pack.UInt32_To_LE(state[..RATE_WORDS], output);
 
-            if (STATE_UINTS == 16)
+            if (STATE_WORDS == 16)
             {
                 SparkleEngine.SparkleOpt16(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state[..RATE_UINTS], output[16..]);
+                Pack.UInt32_To_LE(state[..RATE_WORDS], output[16..]);
                 SparkleEngine.SparkleOpt16(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state[..RATE_UINTS], output[32..]);
+                Pack.UInt32_To_LE(state[..RATE_WORDS], output[32..]);
             }
             else
             {
                 SparkleEngine.SparkleOpt12(state, SPARKLE_STEPS_SLIM);
-                Pack.UInt32_To_LE(state[..RATE_UINTS], output[16..]);
+                Pack.UInt32_To_LE(state[..RATE_WORDS], output[16..]);
             }
 
             Reset();
@@ -280,7 +275,7 @@ namespace Org.BouncyCastle.Crypto.Digests
             state[3] ^= t3 ^ tx;
             state[4] ^= ty;
             state[5] ^= tx;
-            if (STATE_UINTS == 16)
+            if (STATE_WORDS == 16)
             {
                 state[6] ^= ty;
                 state[7] ^= tx;
diff --git a/crypto/src/crypto/engines/SparkleEngine.cs b/crypto/src/crypto/engines/SparkleEngine.cs
index cd6586623..13aaf1edf 100644
--- a/crypto/src/crypto/engines/SparkleEngine.cs
+++ b/crypto/src/crypto/engines/SparkleEngine.cs
@@ -563,7 +563,7 @@ namespace Org.BouncyCastle.Crypto.Engines
                     uint s_j = state[j];
                     if (forEncryption)
                     {
-                        state[i] = s_j       ^ buffer[i] ^ state[RATE_WORDS + i];
+                        state[i] =       s_j ^ buffer[i] ^ state[RATE_WORDS + i];
                         state[j] = s_i ^ s_j ^ buffer[j] ^ state[RATE_WORDS + (j & CAP_MASK)];
                     }
                     else
@@ -817,7 +817,7 @@ namespace Org.BouncyCastle.Crypto.Engines
                 uint d_i = Pack.LE_To_UInt32(buffer, bufOff + (i * 4));
                 uint d_j = Pack.LE_To_UInt32(buffer, bufOff + (j * 4));
 
-                state[i] = s_j       ^ d_i ^ state[RATE_WORDS + i];
+                state[i] =       s_j ^ d_i ^ state[RATE_WORDS + i];
                 state[j] = s_i ^ s_j ^ d_j ^ state[RATE_WORDS + (j & CAP_MASK)];
             }
 
@@ -868,7 +868,7 @@ namespace Org.BouncyCastle.Crypto.Engines
                 uint d_i = Pack.LE_To_UInt32(buffer, bufOff + (i * 4));
                 uint d_j = Pack.LE_To_UInt32(buffer, bufOff + (j * 4));
 
-                state[i] = s_j       ^ d_i ^ state[RATE_WORDS + i];
+                state[i] =       s_j ^ d_i ^ state[RATE_WORDS + i];
                 state[j] = s_i ^ s_j ^ d_j ^ state[RATE_WORDS + (j & CAP_MASK)];
 
                 Pack.UInt32_To_LE(d_i ^ s_i, output, outOff + (i * 4));
@@ -883,26 +883,35 @@ namespace Org.BouncyCastle.Crypto.Engines
 
         private void ProcessFinalAad()
         {
-            // Authentication of Last Block
-
-            // addition of ant A0 or A1 to the state
-            state[STATE_WORDS - 1] ^= (m_bufPos < RATE_BYTES) ? _A0 : _A1;
-
-            // Rho and rate-whitening for the authentication of the last associated-data block.
-            uint[] buffer = new uint[RATE_WORDS];
-            for (int i = 0; i < m_bufPos; ++i)
+            // addition of constant A0 or A1 to the state
+            if (m_bufPos < RATE_BYTES)
             {
-                buffer[i >> 2] |= (uint)m_buf[i] << ((i & 3) << 3);
+                state[STATE_WORDS - 1] ^= _A0;
+
+                // padding
+                m_buf[m_bufPos] = 0x80;
+                while (++m_bufPos < RATE_BYTES)
+                {
+                    m_buf[m_bufPos] = 0x00;
+                }
             }
-            if (m_bufPos < RATE_BYTES)
-            {  // padding
-                buffer[m_bufPos >> 2] |= 0x80U << ((m_bufPos & 3) << 3);
+            else
+            {
+                state[STATE_WORDS - 1] ^= _A1;
             }
-            for (int i = 0, j = RATE_WORDS / 2; i < RATE_WORDS / 2; i++, j++)
+
+            for (int i = 0; i < RATE_WORDS / 2; ++i)
             {
-                uint tmp = state[i];
-                state[i] = state[j] ^ buffer[i] ^ state[RATE_WORDS + i];
-                state[j] ^= tmp ^ buffer[j] ^ state[RATE_WORDS + (j & CAP_MASK)];
+                int j = i + (RATE_WORDS / 2);
+
+                uint s_i = state[i];
+                uint s_j = state[j];
+
+                uint d_i = Pack.LE_To_UInt32(m_buf, i * 4);
+                uint d_j = Pack.LE_To_UInt32(m_buf, j * 4);
+
+                state[i] =       s_j ^ d_i ^ state[RATE_WORDS + i];
+                state[j] = s_i ^ s_j ^ d_j ^ state[RATE_WORDS + (j & CAP_MASK)];
             }
 
             SparkleOpt(state, SPARKLE_STEPS_BIG);