diff --git a/crypto/src/math/ec/rfc7748/X25519Field.cs b/crypto/src/math/ec/rfc7748/X25519Field.cs
index c3373c7ea..5c9eadc6b 100644
--- a/crypto/src/math/ec/rfc7748/X25519Field.cs
+++ b/crypto/src/math/ec/rfc7748/X25519Field.cs
@@ -3,10 +3,6 @@ using System.Diagnostics;
using Org.BouncyCastle.Math.Raw;
-#if NET5_0_OR_GREATER
-using static System.Math;
-#endif
-
namespace Org.BouncyCastle.Math.EC.Rfc7748
{
public static class X25519Field
@@ -959,361 +955,5 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
z[i] = 0;
}
}
-
-#if NET5_0_OR_GREATER
-
- public const int Size64 = 5;
-
- private const long M51 = 0x0007FFFFFFFFFFFFL;
-
- private static readonly long[] RootNegOne64 = { 0x00061B274A0EA0B0L, 0x0000D5A5FC8F189DL, 0x0007EF5E9CBD0C60L,
- 0x00078595A6804C9EL, 0x0002B8324804FC1DL };
-
- public static void Add(ReadOnlySpan<long> x, ReadOnlySpan<long> y, Span<long> z)
- {
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = x[i] + y[i];
- }
- }
-
- public static void AddOne(Span<long> z)
- {
- z[0] += 1L;
- }
-
- public static void Apm(ReadOnlySpan<long> x, ReadOnlySpan<long> y, Span<long> zp, Span<long> zm)
- {
- for (int i = 0; i < Size64; ++i)
- {
- long xi = x[i], yi = y[i];
- zp[i] = xi + yi;
- zm[i] = xi - yi;
- }
- }
-
- public static long AreEqual(ReadOnlySpan<long> x, ReadOnlySpan<long> y)
- {
- long d = 0;
- for (int i = 0; i < Size64; ++i)
- {
- d |= x[i] ^ y[i];
- }
- return (~d & (d - 1)) >> 63;
- }
-
- public static bool AreEqualVar(ReadOnlySpan<long> x, ReadOnlySpan<long> y)
- {
- return 0 != AreEqual(x, y);
- }
-
- public static void CMov(long cond, ReadOnlySpan<long> x, Span<long> z)
- {
- Debug.Assert(0L == cond || -1L == cond);
-
- for (int i = 0; i < Size64; ++i)
- {
- long z_i = z[i], diff = z_i ^ x[i];
- z_i ^= diff & cond;
- z[i] = z_i;
- }
- }
-
- public static void CNegate(long negate, Span<long> z)
- {
- Debug.Assert(negate >> 1 == 0L);
-
- long mask = 0L - negate;
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = (z[i] ^ mask) - mask;
- }
- }
-
- public static void Copy(ReadOnlySpan<long> x, Span<long> z)
- {
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = x[i];
- }
- }
-
- public static void CSwap(long swap, Span<long> a, Span<long> b)
- {
- Debug.Assert(swap >> 1 == 0);
- Debug.Assert(a != b);
-
- long mask = 0 - swap;
- for (int i = 0; i < Size64; ++i)
- {
- long ai = a[i], bi = b[i];
- long dummy = mask & (ai ^ bi);
- a[i] = ai ^ dummy;
- b[i] = bi ^ dummy;
- }
- }
-
- public static long IsOne(ReadOnlySpan<long> x)
- {
- long d = x[0] ^ 1L;
- for (int i = 1; i < Size64; ++i)
- {
- d |= x[i];
- }
- return (~d & (d - 1)) >> 63;
- }
-
- public static bool IsOneVar(ReadOnlySpan<long> x)
- {
- return 0 != IsOne(x);
- }
-
- public static long IsZero(ReadOnlySpan<long> x)
- {
- long d = x[0];
- for (int i = 1; i < Size64; ++i)
- {
- d |= x[i];
- }
- return (~d & (d - 1)) >> 63;
- }
-
- public static bool IsZeroVar(ReadOnlySpan<long> x)
- {
- return 0 != IsZero(x);
- }
-
- public static void Mul(ReadOnlySpan<long> x, ReadOnlySpan<long> y, Span<long> z)
- {
- long x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3], x4 = x[4];
- long y0 = y[0], y1 = y[1], y2 = y[2], y3 = y[3], y4 = y[4];
- long z0, z1, z2, z3, z4, t5, t6, t7, t8, t9;
-
- long hi00 = BigMul(x0, y0, out long lo00);
-
- z0 = lo00 & M51;
- z1 = (hi00 << 13)
- + (lo00 >> 51);
-
- long hi01 = BigMul(x0, y1, out long lo01);
- long hi10 = BigMul(x1, y0, out long lo10);
-
- z1 += (lo01 & M51) + (lo10 & M51);
- z2 = ((hi01 + hi10) << 13)
- + (lo01 >> 51) + (lo10 >> 51);
-
- long hi02 = BigMul(x0, y2, out long lo02);
- long hi11 = BigMul(x1, y1, out long lo11);
- long hi20 = BigMul(x2, y0, out long lo20);
-
- z2 += (lo02 & M51) + (lo11 & M51) + (lo20 & M51);
- z3 = ((hi02 + hi11 + hi20) << 13)
- + (lo02 >> 51) + (lo11 >> 51) + (lo20 >> 51);
-
- long hi03 = BigMul(x0, y3, out long lo03);
- long hi12 = BigMul(x1, y2, out long lo12);
- long hi21 = BigMul(x2, y1, out long lo21);
- long hi30 = BigMul(x3, y0, out long lo30);
-
- z3 += (lo03 & M51) + (lo12 & M51) + (lo21 & M51) + (lo30 & M51);
- z4 = ((hi03 + hi12 + hi21 + hi30) << 13)
- + (lo03 >> 51) + (lo12 >> 51) + (lo21 >> 51) + (lo30 >> 51);
-
- long hi04 = BigMul(x0, y4, out long lo04);
- long hi13 = BigMul(x1, y3, out long lo13);
- long hi22 = BigMul(x2, y2, out long lo22);
- long hi31 = BigMul(x3, y1, out long lo31);
- long hi40 = BigMul(x4, y0, out long lo40);
-
- z4 += (lo04 & M51) + (lo13 & M51) + (lo22 & M51) + (lo31 & M51) + (lo40 & M51);
- t5 = ((hi04 + hi13 + hi22 + hi31 + hi40) << 13)
- + (lo04 >> 51) + (lo13 >> 51) + (lo22 >> 51) + (lo31 >> 51) + (lo40 >> 51);
-
- long hi14 = BigMul(x1, y4, out long lo14);
- long hi23 = BigMul(x2, y3, out long lo23);
- long hi32 = BigMul(x3, y2, out long lo32);
- long hi41 = BigMul(x4, y1, out long lo41);
-
- t5 += (lo14 & M51) + (lo23 & M51) + (lo32 & M51) + (lo41 & M51);
- t6 = ((hi14 + hi23 + hi32 + hi41) << 13)
- + (lo14 >> 51) + (lo23 >> 51) + (lo32 >> 51) + (lo41 >> 51);
-
- long hi24 = BigMul(x2, y4, out long lo24);
- long hi33 = BigMul(x3, y3, out long lo33);
- long hi42 = BigMul(x4, y2, out long lo42);
-
- t6 += (lo24 & M51) + (lo33 & M51) + (lo42 & M51);
- t7 = ((hi24 + hi33 + hi42) << 13)
- + (lo24 >> 51) + (lo33 >> 51) + (lo42 >> 51);
-
- long hi34 = BigMul(x3, y4, out long lo34);
- long hi43 = BigMul(x4, y3, out long lo43);
-
- t7 += (lo34 & M51) + (lo43 & M51);
- t8 = ((hi34 + hi43) << 13)
- + (lo34 >> 51) + (lo43 >> 51);
-
- long hi44 = BigMul(x4, y4, out long lo44);
-
- t8 += lo44 & M51;
- t9 = (hi44 << 13)
- + (lo44 >> 51);
-
- z3 += t8 * 19;
- z4 += t9 * 19;
-
- z4 += z3 >> 51; z3 &= M51;
- t5 += z4 >> 51; z4 &= M51;
-
- z0 += t5 * 19;
- z1 += t6 * 19;
- z2 += t7 * 19;
-
- z1 += z0 >> 51; z0 &= M51;
- z2 += z1 >> 51; z1 &= M51;
- z3 += z2 >> 51; z2 &= M51;
- z4 += z3 >> 51; z3 &= M51;
-
- z[0] = z0; z[1] = z1; z[2] = z2; z[3] = z3; z[4] = z4;
- }
-
- public static void Negate(ReadOnlySpan<long> x, Span<long> z)
- {
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = -x[i];
- }
- }
-
- public static void Normalize(Span<long> z)
- {
- long x = (z[4] >> 50) & 1L;
- Reduce(z, x);
- Reduce(z, -x);
- Debug.Assert(z[4] >> 51 == 0);
- }
-
- public static void One(Span<long> z)
- {
- z[0] = 1L;
- for (int i = 1; i < Size64; ++i)
- {
- z[i] = 0L;
- }
- }
-
- private static void PowPm5d8(ReadOnlySpan<long> x, Span<long> rx2, Span<long> rz)
- {
- // z = x^((p-5)/8) = x^FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFD
- // (250 1s) (1 0s) (1 1s)
- // Addition chain: [1] 2 3 5 10 15 25 50 75 125 [250]
-
- Span<long> x2 = rx2; Sqr(x, x2); Mul(x, x2, x2);
- Span<long> x3 = stackalloc long[Size64]; Sqr(x2, x3); Mul(x, x3, x3);
- Span<long> x5 = x3; Sqr(x3, 2, x5); Mul(x2, x5, x5);
- Span<long> x10 = stackalloc long[Size64]; Sqr(x5, 5, x10); Mul(x5, x10, x10);
- Span<long> x15 = stackalloc long[Size64]; Sqr(x10, 5, x15); Mul(x5, x15, x15);
- Span<long> x25 = x5; Sqr(x15, 10, x25); Mul(x10, x25, x25);
- Span<long> x50 = x10; Sqr(x25, 25, x50); Mul(x25, x50, x50);
- Span<long> x75 = x15; Sqr(x50, 25, x75); Mul(x25, x75, x75);
- Span<long> x125 = x25; Sqr(x75, 50, x125); Mul(x50, x125, x125);
- Span<long> x250 = x50; Sqr(x125, 125, x250); Mul(x125, x250, x250);
-
- Span<long> t = x125;
- Sqr(x250, 2, t);
- Mul(t, x, rz);
- }
-
- private static void Reduce(Span<long> z, long x)
- {
- long t = z[4], z4 = t & M51;
- t = (t >> 51) + x;
-
- long cc = t * 19;
- cc += z[0]; z[0] = cc & M51; cc >>= 51;
- cc += z[1]; z[1] = cc & M51; cc >>= 51;
- cc += z[2]; z[2] = cc & M51; cc >>= 51;
- cc += z[3]; z[3] = cc & M51; cc >>= 51;
- cc += z4 ; z[4] = cc;
- }
-
- public static void Sqr(ReadOnlySpan<long> x, Span<long> z)
- {
- Mul(x, x, z);
- }
-
- public static void Sqr(ReadOnlySpan<long> x, int n, Span<long> z)
- {
- Debug.Assert(n > 0);
-
- Sqr(x, z);
-
- while (--n > 0)
- {
- Sqr(z, z);
- }
- }
-
- public static bool SqrtRatioVar(ReadOnlySpan<long> u, ReadOnlySpan<long> v, Span<long> z)
- {
- Span<long> uv3 = stackalloc long[Size64];
- Span<long> uv7 = stackalloc long[Size64];
-
- Mul(u, v, uv3);
- Sqr(v, uv7);
- Mul(uv3, uv7, uv3);
- Sqr(uv7, uv7);
- Mul(uv7, uv3, uv7);
-
- Span<long> t = stackalloc long[Size64];
- Span<long> x = stackalloc long[Size64];
- PowPm5d8(uv7, t, x);
- Mul(x, uv3, x);
-
- Span<long> vx2 = stackalloc long[Size64];
- Sqr(x, vx2);
- Mul(vx2, v, vx2);
-
- Sub(vx2, u, t);
- Normalize(t);
- if (IsZeroVar(t))
- {
- Copy(x, z);
- return true;
- }
-
- Add(vx2, u, t);
- Normalize(t);
- if (IsZeroVar(t))
- {
- Mul(x, RootNegOne64, z);
- return true;
- }
-
- return false;
- }
-
- public static void Sub(ReadOnlySpan<long> x, ReadOnlySpan<long> y, Span<long> z)
- {
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = x[i] - y[i];
- }
- }
-
- public static void SubOne(Span<long> z)
- {
- z[0] -= 1L;
- }
-
- public static void Zero(Span<long> z)
- {
- for (int i = 0; i < Size64; ++i)
- {
- z[i] = 0L;
- }
- }
-
-#endif
}
}
|
