Refactor for Mayo

Author: gefeili

core/src/main/java/org/bouncycastle/pqc/crypto/mayo/GF16Utils.java

@@ -101,27 +101,6 @@ public static void mulAddMUpperTriangularMatXMat(int mVecLimbs, long[] bsMat, by
         }
     }
 
-    /**
-     * Computes P1_times_O.
-     * <p>
-     * In C:
-     * P1_times_O(p, P1, O, acc) calls:
-     * mul_add_m_upper_triangular_mat_x_mat(PARAM_m_vec_limbs(p), P1, O, acc, PARAM_v(p), PARAM_v(p), PARAM_o(p), 1);
-     *
-     * @param p   the parameter object.
-     * @param P1  the P1 matrix as a long[] array.
-     * @param O   the O matrix as a byte[] array.
-     * @param acc the output accumulator (long[] array).
-     */
-    public static void P1TimesO(MayoParameters p, long[] P1, byte[] O, long[] acc)
-    {
-        int mVecLimbs = p.getMVecLimbs();
-        int paramV = p.getV();
-        int paramO = p.getO();
-        // Here, bsMatRows and bsMatCols are both paramV, and matCols is paramO, triangular=1.
-        mulAddMUpperTriangularMatXMat(mVecLimbs, P1, O, acc, paramV, paramV, paramO, 1);
-    }
-
     /**
      * Multiplies the transpose of a single matrix with m matrices and adds the result into acc.
      *
@@ -304,10 +283,7 @@ public static long mulFx8(byte a, long b)
         int aa = a & 0xFF;
         // Carryless multiplication: for each bit in 'aa' (considering only the lower 4 bits),
         // if that bit is set, multiply 'b' (by 1, 2, 4, or 8) and XOR the result.
-        long p = ((aa & 1) * b)
-            ^ ((aa & 2) * b)
-            ^ ((aa & 4) * b)
-            ^ ((aa & 8) * b);
+        long p = ((aa & 1) * b) ^ ((aa & 2) * b) ^ ((aa & 4) * b) ^ ((aa & 8) * b);
 
         // Reduction mod (x^4 + x + 1): process each byte in parallel.
         long topP = p & 0xf0f0f0f0f0f0f0f0L;
@@ -366,28 +342,6 @@ public static void matAdd(byte[] a, int aOff, byte[] b, int bOff, byte[] c, int
         }
     }
 
-    /**
-     * Returns 0x00 if a equals b, otherwise returns 0xFF.
-     * This operation is performed in constant time.
-     *
-     * @param a an 8-bit value
-     * @param b an 8-bit value
-     * @return 0x00 if a == b, 0xFF if a != b
-     */
-    public static byte ctCompare8(byte a, byte b)
-    {
-        // Compute the difference between a and b using XOR.
-        // Masking with 0xFF ensures we work with values in 0..255.
-        int diff = (a ^ b) & 0xFF;
-        // Negate the difference.
-        int negDiff = -diff;
-        // Right shift by 31 bits (since 8*sizeof(uint32_t)-1 equals 31 for 32-bit integers).
-        // If diff is 0, then -diff is 0, and shifting yields 0.
-        // If diff is nonzero, -diff is negative, so the arithmetic shift yields -1 (0xFFFFFFFF),
-        // which when cast to a byte becomes 0xFF.
-        return (byte) (negDiff >> 31);
-    }
-
     public static void efUnpackMVector(int legs, long[] packedRow, int packedRowOff, byte[] out)
     {
         int outIndex = 0;

core/src/main/java/org/bouncycastle/pqc/crypto/mayo/MayoKeyPairGenerator.java

@@ -72,7 +72,9 @@ public AsymmetricCipherKeyPair generateKeyPair()
         System.arraycopy(P, p1Limbs, P2, 0, P2.length);
 
         // Compute P1 * O + P2 and store the result in P2.
-        GF16Utils.P1TimesO(p, P, O, P2);
+//        GF16Utils.P1TimesO(p, P, O, P2);
+        // Here, bsMatRows and bsMatCols are both paramV, and matCols is paramO, triangular=1.
+        GF16Utils.mulAddMUpperTriangularMatXMat(mVecLimbs, P, O, P2, v, v, o, 1);
 
         // Compute P3 = O^T * (P1*O + P2).
         // Here, treat P2 as the bsMat for the multiplication.

core/src/main/java/org/bouncycastle/pqc/crypto/mayo/MayoParameters.java

@@ -18,7 +18,7 @@ public class MayoParameters
         40,                 // r_bytes
         120159,             // P1_bytes
         24336,              // P2_bytes
-        1404,               // P3_bytes
+        // P3_bytes
         24,                 // csk_bytes
         1420,               // cpk_bytes
         454,                // sig_bytes
@@ -46,7 +46,7 @@ public class MayoParameters
         34,                 // r_bytes
         66560,              // P1_bytes
         34816,              // P2_bytes
-        4896,               // P3_bytes
+        // P3_bytes
         24,                 // csk_bytes
         4912,               // cpk_bytes
         186,                // sig_bytes
@@ -74,7 +74,7 @@ public class MayoParameters
         55,                 // r_bytes
         317844,             // P1_bytes
         58320,              // P2_bytes
-        2970,               // P3_bytes
+        // P3_bytes
         32,                 // csk_bytes
         2986,               // cpk_bytes
         681,                // sig_bytes
@@ -102,7 +102,7 @@ public class MayoParameters
         72,                 // r_bytes
         720863,             // P1_bytes
         120984,             // P2_bytes
-        5538,               // P3_bytes
+        // P3_bytes
         40,                 // csk_bytes
         5554,               // cpk_bytes
         964,                // sig_bytes
@@ -129,7 +129,6 @@ public class MayoParameters
     private final int rBytes;
     private final int P1Bytes;
     private final int P2Bytes;
-    private final int P3Bytes;
     private final int cskBytes;
     private final int cpkBytes;
     private final int sigBytes;
@@ -141,7 +140,7 @@ public class MayoParameters
     private final int skSeedBytes;
 
     private MayoParameters(String name, int n, int m, int mVecLimbs, int o, int v, int ACols, int k, int q,
-                           int mBytes, int OBytes, int vBytes, int rBytes, int P1Bytes, int P2Bytes, int P3Bytes,
+                           int mBytes, int OBytes, int vBytes, int rBytes, int P1Bytes, int P2Bytes,
                            int cskBytes, int cpkBytes, int sigBytes, int[] fTail, byte[] fTailArr,
                            int saltBytes, int digestBytes, int pkSeedBytes, int skSeedBytes)
     {
@@ -160,7 +159,6 @@ private MayoParameters(String name, int n, int m, int mVecLimbs, int o, int v, i
         this.rBytes = rBytes;
         this.P1Bytes = P1Bytes;
         this.P2Bytes = P2Bytes;
-        this.P3Bytes = P3Bytes;
         this.cskBytes = cskBytes;
         this.cpkBytes = cpkBytes;
         this.sigBytes = sigBytes;
@@ -315,13 +313,5 @@ public int getP3Limbs()
     {
         return ((o * (o + 1)) / 2) * mVecLimbs;
     }
-
-    /**
-     * Computes: P1_limbs + P2_limbs + P3_limbs
-     */
-    public int getEPKLimbs()
-    {
-        return getP1Limbs() + getP2Limbs() + getP3Limbs();
-    }
 }