Updates to raw math classes from bc-java

6 files changed, 148 insertions, 42 deletions

diff --git a/crypto/src/math/raw/Nat.cs b/crypto/src/math/raw/Nat.cs
index 5cf5fe218..9786d3ecf 100644
--- a/crypto/src/math/raw/Nat.cs
+++ b/crypto/src/math/raw/Nat.cs
@@ -161,6 +161,31 @@ namespace Org.BouncyCastle.Math.Raw
             return (uint)c;
         }
 
+        public static uint AddTo(int len, uint[] x, int xOff, uint[] z, int zOff, uint cIn)
+        {
+            ulong c = cIn;
+            for (int i = 0; i < len; ++i)
+            {
+                c += (ulong)x[xOff + i] + z[zOff + i];
+                z[zOff + i] = (uint)c;
+                c >>= 32;
+            }
+            return (uint)c;
+        }
+
+        public static uint AddToEachOther(int len, uint[] u, int uOff, uint[] v, int vOff)
+        {
+            ulong c = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                c += (ulong)u[uOff + i] + v[vOff + i];
+                u[uOff + i] = (uint)c;
+                v[vOff + i] = (uint)c;
+                c >>= 32;
+            }
+            return (uint)c;
+        }
+
         public static uint AddWordAt(int len, uint x, uint[] z, int zPos)
         {
             Debug.Assert(zPos <= (len - 1));
@@ -297,6 +322,32 @@ namespace Org.BouncyCastle.Math.Raw
             return new ulong[len];
         }
 
+        public static int CSub(int len, int mask, uint[] x, uint[] y, uint[] z)
+        {
+            long MASK = (uint)-(mask & 1);
+            long c = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                c += (long)x[i] - (y[i] & MASK);
+                z[i] = (uint)c;
+                c >>= 32;
+            }
+            return (int)c;
+        }
+
+        public static int CSub(int len, int mask, uint[] x, int xOff, uint[] y, int yOff, uint[] z, int zOff)
+        {
+            long MASK = (uint)-(mask & 1);
+            long c = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                c += (long)x[xOff + i] - (y[yOff + i] & MASK);
+                z[zOff + i] = (uint)c;
+                c >>= 32;
+            }
+            return (int)c;
+        }
+
         public static int Dec(int len, uint[] z)
         {
             for (int i = 0; i < len; ++i)
@@ -554,10 +605,10 @@ namespace Org.BouncyCastle.Math.Raw
             ulong zc = 0;
             for (int i = 0; i < len; ++i)
             {
-                ulong c = MulWordAddTo(len, x[i], y, 0, zz, i) & M;
-                c += zc + (zz[i + len] & M);
-                zz[i + len] = (uint)c;
-                zc = c >> 32;
+                zc += MulWordAddTo(len, x[i], y, 0, zz, i) & M;
+                zc += zz[i + len] & M;
+                zz[i + len] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -567,10 +618,10 @@ namespace Org.BouncyCastle.Math.Raw
             ulong zc = 0;
             for (int i = 0; i < len; ++i)
             {
-                ulong c = MulWordAddTo(len, x[xOff + i], y, yOff, zz, zzOff) & M;
-                c += zc + (zz[zzOff + len] & M);
-                zz[zzOff + len] = (uint)c;
-                zc = c >> 32;
+                zc += MulWordAddTo(len, x[xOff + i], y, yOff, zz, zzOff) & M;
+                zc += zz[zzOff + len] & M;
+                zz[zzOff + len] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;
@@ -902,11 +953,18 @@ namespace Org.BouncyCastle.Math.Raw
             }
             while (j > 0);
 
+            ulong d = 0UL;
+            int zzPos = 2;
+
             for (int i = 1; i < len; ++i)
             {
-                c = SquareWordAdd(x, i, zz);
-                AddWordAt(extLen, c, zz, i << 1);
+                d += SquareWordAddTo(x, i, zz);
+                d += zz[zzPos];
+                zz[zzPos++] = (uint)d; d >>= 32;
+                d += zz[zzPos];
+                zz[zzPos++] = (uint)d; d >>= 32;
             }
+            Debug.Assert(0UL == d);
 
             ShiftUpBit(extLen, zz, x[0] << 31);
         }
@@ -926,15 +984,23 @@ namespace Org.BouncyCastle.Math.Raw
             }
             while (j > 0);
 
+            ulong d = 0UL;
+            int zzPos = zzOff + 2;
+
             for (int i = 1; i < len; ++i)
             {
-                c = SquareWordAdd(x, xOff, i, zz, zzOff);
-                AddWordAt(extLen, c, zz, zzOff, i << 1);
+                d += SquareWordAddTo(x, xOff, i, zz, zzOff);
+                d += zz[zzPos];
+                zz[zzPos++] = (uint)d; d >>= 32;
+                d += zz[zzPos];
+                zz[zzPos++] = (uint)d; d >>= 32;
             }
+            Debug.Assert(0UL == d);
 
             ShiftUpBit(extLen, zz, zzOff, x[xOff] << 31);
         }
 
+        [Obsolete("Use 'SquareWordAddTo' instead")]
         public static uint SquareWordAdd(uint[] x, int xPos, uint[] z)
         {
             ulong c = 0, xVal = (ulong)x[xPos];
@@ -949,6 +1015,7 @@ namespace Org.BouncyCastle.Math.Raw
             return (uint)c;
         }
 
+        [Obsolete("Use 'SquareWordAddTo' instead")]
         public static uint SquareWordAdd(uint[] x, int xOff, int xPos, uint[] z, int zOff)
         {
             ulong c = 0, xVal = (ulong)x[xOff + xPos];
@@ -964,6 +1031,35 @@ namespace Org.BouncyCastle.Math.Raw
             return (uint)c;
         }
 
+        public static uint SquareWordAddTo(uint[] x, int xPos, uint[] z)
+        {
+            ulong c = 0, xVal = (ulong)x[xPos];
+            int i = 0;
+            do
+            {
+                c += xVal * x[i] + z[xPos + i];
+                z[xPos + i] = (uint)c;
+                c >>= 32;
+            }
+            while (++i < xPos);
+            return (uint)c;
+        }
+
+        public static uint SquareWordAddTo(uint[] x, int xOff, int xPos, uint[] z, int zOff)
+        {
+            ulong c = 0, xVal = (ulong)x[xOff + xPos];
+            int i = 0;
+            do
+            {
+                c += xVal * (x[xOff + i] & M) + (z[xPos + zOff] & M);
+                z[xPos + zOff] = (uint)c;
+                c >>= 32;
+                ++zOff;
+            }
+            while (++i < xPos);
+            return (uint)c;
+        }
+
         public static int Sub(int len, uint[] x, uint[] y, uint[] z)
         {
             long c = 0;
diff --git a/crypto/src/math/raw/Nat128.cs b/crypto/src/math/raw/Nat128.cs
index 27ed5abe4..7617a9ee9 100644
--- a/crypto/src/math/raw/Nat128.cs
+++ b/crypto/src/math/raw/Nat128.cs
@@ -422,9 +422,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_3 + zz[i + 3];
                 zz[i + 3] = (uint)c;
                 c >>= 32;
-                c += zc + zz[i + 4];
-                zz[i + 4] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[i + 4];
+                zz[i + 4] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -452,9 +453,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_3 + zz[zzOff + 3];
                 zz[zzOff + 3] = (uint)c;
                 c >>= 32;
-                c += zc + zz[zzOff + 4];
-                zz[zzOff + 4] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[zzOff + 4];
+                zz[zzOff + 4] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;
diff --git a/crypto/src/math/raw/Nat160.cs b/crypto/src/math/raw/Nat160.cs
index 57212cae0..f5514d7b4 100644
--- a/crypto/src/math/raw/Nat160.cs
+++ b/crypto/src/math/raw/Nat160.cs
@@ -384,9 +384,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_4 + zz[i + 4];
                 zz[i + 4] = (uint)c;
                 c >>= 32;
-                c += zc + zz[i + 5];
-                zz[i + 5] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[i + 5];
+                zz[i + 5] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -418,9 +419,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_4 + zz[zzOff + 4];
                 zz[zzOff + 4] = (uint)c;
                 c >>= 32;
-                c += zc + zz[zzOff + 5];
-                zz[zzOff + 5] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[zzOff + 5];
+                zz[zzOff + 5] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;
diff --git a/crypto/src/math/raw/Nat192.cs b/crypto/src/math/raw/Nat192.cs
index 06c75aa54..1311dee04 100644
--- a/crypto/src/math/raw/Nat192.cs
+++ b/crypto/src/math/raw/Nat192.cs
@@ -498,9 +498,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_5 + zz[i + 5];
                 zz[i + 5] = (uint)c;
                 c >>= 32;
-                c += zc + zz[i + 6];
-                zz[i + 6] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[i + 6];
+                zz[i + 6] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -536,9 +537,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_5 + zz[zzOff + 5];
                 zz[zzOff + 5] = (uint)c;
                 c >>= 32;
-                c += zc + zz[zzOff + 6];
-                zz[zzOff + 6] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[zzOff + 6];
+                zz[zzOff + 6] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;
diff --git a/crypto/src/math/raw/Nat224.cs b/crypto/src/math/raw/Nat224.cs
index ff1eb6306..565abcb9c 100644
--- a/crypto/src/math/raw/Nat224.cs
+++ b/crypto/src/math/raw/Nat224.cs
@@ -509,9 +509,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_6 + zz[i + 6];
                 zz[i + 6] = (uint)c;
                 c >>= 32;
-                c += zc + zz[i + 7];
-                zz[i + 7] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[i + 7];
+                zz[i + 7] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -551,9 +552,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_6 + zz[zzOff + 6];
                 zz[zzOff + 6] = (uint)c;
                 c >>= 32;
-                c += zc + zz[zzOff + 7];
-                zz[zzOff + 7] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[zzOff + 7];
+                zz[zzOff + 7] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;
diff --git a/crypto/src/math/raw/Nat256.cs b/crypto/src/math/raw/Nat256.cs
index 2be03d642..5c473c405 100644
--- a/crypto/src/math/raw/Nat256.cs
+++ b/crypto/src/math/raw/Nat256.cs
@@ -632,9 +632,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_7 + zz[i + 7];
                 zz[i + 7] = (uint)c;
                 c >>= 32;
-                c += zc + zz[i + 8];
-                zz[i + 8] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[i + 8];
+                zz[i + 8] = (uint)zc;
+                zc >>= 32;
             }
             return (uint)zc;
         }
@@ -678,9 +679,10 @@ namespace Org.BouncyCastle.Math.Raw
                 c += x_i * y_7 + zz[zzOff + 7];
                 zz[zzOff + 7] = (uint)c;
                 c >>= 32;
-                c += zc + zz[zzOff + 8];
-                zz[zzOff + 8] = (uint)c;
-                zc = c >> 32;
+
+                zc += c + zz[zzOff + 8];
+                zz[zzOff + 8] = (uint)zc;
+                zc >>= 32;
                 ++zzOff;
             }
             return (uint)zc;