using System; using System.Diagnostics; using Org.BouncyCastle.Math.Raw; namespace Org.BouncyCastle.Math.EC.Custom.Sec { internal class SecT131Field { private const ulong M03 = ulong.MaxValue >> 61; private const ulong M44 = ulong.MaxValue >> 20; public static void Add(ulong[] x, ulong[] y, ulong[] z) { z[0] = x[0] ^ y[0]; z[1] = x[1] ^ y[1]; z[2] = x[2] ^ y[2]; } public static void AddExt(ulong[] xx, ulong[] yy, ulong[] zz) { zz[0] = xx[0] ^ yy[0]; zz[1] = xx[1] ^ yy[1]; zz[2] = xx[2] ^ yy[2]; zz[3] = xx[3] ^ yy[3]; zz[4] = xx[4] ^ yy[4]; } public static void AddOne(ulong[] x, ulong[] z) { z[0] = x[0] ^ 1UL; z[1] = x[1]; z[2] = x[2]; } public static ulong[] FromBigInteger(BigInteger x) { ulong[] z = Nat192.FromBigInteger64(x); Reduce61(z, 0); return z; } public static void Invert(ulong[] x, ulong[] z) { if (Nat192.IsZero64(x)) throw new InvalidOperationException(); // Itoh-Tsujii inversion ulong[] t0 = Nat192.Create64(); ulong[] t1 = Nat192.Create64(); Square(x, t0); Multiply(t0, x, t0); SquareN(t0, 2, t1); Multiply(t1, t0, t1); SquareN(t1, 4, t0); Multiply(t0, t1, t0); SquareN(t0, 8, t1); Multiply(t1, t0, t1); SquareN(t1, 16, t0); Multiply(t0, t1, t0); SquareN(t0, 32, t1); Multiply(t1, t0, t1); Square(t1, t1); Multiply(t1, x, t1); SquareN(t1, 65, t0); Multiply(t0, t1, t0); Square(t0, z); } public static void Multiply(ulong[] x, ulong[] y, ulong[] z) { ulong[] tt = Nat192.CreateExt64(); ImplMultiply(x, y, tt); Reduce(tt, z); } public static void MultiplyAddToExt(ulong[] x, ulong[] y, ulong[] zz) { ulong[] tt = Nat192.CreateExt64(); ImplMultiply(x, y, tt); AddExt(zz, tt, zz); } public static void Reduce(ulong[] xx, ulong[] z) { ulong x0 = xx[0], x1 = xx[1], x2 = xx[2], x3 = xx[3], x4 = xx[4]; x1 ^= (x4 << 61) ^ (x4 << 63); x2 ^= (x4 >> 3) ^ (x4 >> 1) ^ x4 ^ (x4 << 5); x3 ^= (x4 >> 59); x0 ^= (x3 << 61) ^ (x3 << 63); x1 ^= (x3 >> 3) ^ (x3 >> 1) ^ x3 ^ (x3 << 5); x2 ^= (x3 >> 59); ulong t = x2 >> 3; z[0] = x0 ^ t ^ (t << 2) ^ (t << 3) ^ (t << 8); z[1] = x1 ^ (t >> 56); z[2] = x2 & M03; } public static void Reduce61(ulong[] z, int zOff) { ulong z2 = z[zOff + 2], t = z2 >> 3; z[zOff ] ^= t ^ (t << 2) ^ (t << 3) ^ (t << 8); z[zOff + 1] ^= (t >> 56); z[zOff + 2] = z2 & M03; } public static void Square(ulong[] x, ulong[] z) { ulong[] tt = Nat.Create64(5); ImplSquare(x, tt); Reduce(tt, z); } public static void SquareAddToExt(ulong[] x, ulong[] zz) { ulong[] tt = Nat.Create64(5); ImplSquare(x, tt); AddExt(zz, tt, zz); } public static void SquareN(ulong[] x, int n, ulong[] z) { Debug.Assert(n > 0); ulong[] tt = Nat.Create64(5); ImplSquare(x, tt); Reduce(tt, z); while (--n > 0) { ImplSquare(z, tt); Reduce(tt, z); } } protected static void ImplCompactExt(ulong[] zz) { ulong z0 = zz[0], z1 = zz[1], z2 = zz[2], z3 = zz[3], z4 = zz[4], z5 = zz[5]; zz[0] = z0 ^ (z1 << 44); zz[1] = (z1 >> 20) ^ (z2 << 24); zz[2] = (z2 >> 40) ^ (z3 << 4) ^ (z4 << 48); zz[3] = (z3 >> 60) ^ (z5 << 28) ^ (z4 >> 16); zz[4] = (z5 >> 36); zz[5] = 0; } protected static void ImplMultiply(ulong[] x, ulong[] y, ulong[] zz) { /* * "Five-way recursion" as described in "Batch binary Edwards", Daniel J. Bernstein. */ ulong f0 = x[0], f1 = x[1], f2 = x[2]; f2 = ((f1 >> 24) ^ (f2 << 40)) & M44; f1 = ((f0 >> 44) ^ (f1 << 20)) & M44; f0 &= M44; ulong g0 = y[0], g1 = y[1], g2 = y[2]; g2 = ((g1 >> 24) ^ (g2 << 40)) & M44; g1 = ((g0 >> 44) ^ (g1 << 20)) & M44; g0 &= M44; ulong[] H = new ulong[10]; ImplMulw(f0, g0, H, 0); // H(0) 44/43 bits ImplMulw(f2, g2, H, 2); // H(INF) 44/41 bits ulong t0 = f0 ^ f1 ^ f2; ulong t1 = g0 ^ g1 ^ g2; ImplMulw(t0, t1, H, 4); // H(1) 44/43 bits ulong t2 = (f1 << 1) ^ (f2 << 2); ulong t3 = (g1 << 1) ^ (g2 << 2); ImplMulw(f0 ^ t2, g0 ^ t3, H, 6); // H(t) 44/45 bits ImplMulw(t0 ^ t2, t1 ^ t3, H, 8); // H(t + 1) 44/45 bits ulong t4 = H[6] ^ H[8]; ulong t5 = H[7] ^ H[9]; Debug.Assert(t5 >> 44 == 0); // Calculate V ulong v0 = (t4 << 1) ^ H[6]; ulong v1 = t4 ^ (t5 << 1) ^ H[7]; ulong v2 = t5; // Calculate U ulong u0 = H[0]; ulong u1 = H[1] ^ H[0] ^ H[4]; ulong u2 = H[1] ^ H[5]; // Calculate W ulong w0 = u0 ^ v0 ^ (H[2] << 4) ^ (H[2] << 1); ulong w1 = u1 ^ v1 ^ (H[3] << 4) ^ (H[3] << 1); ulong w2 = u2 ^ v2; // Propagate carries w1 ^= (w0 >> 44); w0 &= M44; w2 ^= (w1 >> 44); w1 &= M44; Debug.Assert((w0 & 1UL) == 0); // Divide W by t w0 = (w0 >> 1) ^ ((w1 & 1UL) << 43); w1 = (w1 >> 1) ^ ((w2 & 1UL) << 43); w2 = (w2 >> 1); // Divide W by (t + 1) w0 ^= (w0 << 1); w0 ^= (w0 << 2); w0 ^= (w0 << 4); w0 ^= (w0 << 8); w0 ^= (w0 << 16); w0 ^= (w0 << 32); w0 &= M44; w1 ^= (w0 >> 43); w1 ^= (w1 << 1); w1 ^= (w1 << 2); w1 ^= (w1 << 4); w1 ^= (w1 << 8); w1 ^= (w1 << 16); w1 ^= (w1 << 32); w1 &= M44; w2 ^= (w1 >> 43); w2 ^= (w2 << 1); w2 ^= (w2 << 2); w2 ^= (w2 << 4); w2 ^= (w2 << 8); w2 ^= (w2 << 16); w2 ^= (w2 << 32); Debug.Assert(w2 >> 42 == 0); zz[0] = u0; zz[1] = u1 ^ w0 ^ H[2]; zz[2] = u2 ^ w1 ^ w0 ^ H[3]; zz[3] = w2 ^ w1; zz[4] = w2 ^ H[2]; zz[5] = H[3]; ImplCompactExt(zz); } protected static void ImplMulw(ulong x, ulong y, ulong[] z, int zOff) { Debug.Assert(x >> 45 == 0); Debug.Assert(y >> 45 == 0); ulong[] u = new ulong[8]; //u[0] = 0; u[1] = y; u[2] = u[1] << 1; u[3] = u[2] ^ y; u[4] = u[2] << 1; u[5] = u[4] ^ y; u[6] = u[3] << 1; u[7] = u[6] ^ y; uint j = (uint)x; ulong g, h = 0, l = u[j & 7] ^ u[(j >> 3) & 7] << 3 ^ u[(j >> 6) & 7] << 6; int k = 33; do { j = (uint)(x >> k); g = u[j & 7] ^ u[(j >> 3) & 7] << 3 ^ u[(j >> 6) & 7] << 6 ^ u[(j >> 9) & 7] << 9; l ^= (g << k); h ^= (g >> -k); } while ((k -= 12) > 0); Debug.Assert(h >> 25 == 0); z[zOff ] = l & M44; z[zOff + 1] = (l >> 44) ^ (h << 20); } protected static void ImplSquare(ulong[] x, ulong[] zz) { Interleave.Expand64To128(x[0], zz, 0); Interleave.Expand64To128(x[1], zz, 2); zz[4] = Interleave.Expand8to16((uint)x[2]); } } }