| package org.bouncycastle.math.ec.custom.sec; |
| |
| import java.math.BigInteger; |
| |
| import org.bouncycastle.math.raw.Interleave; |
| import org.bouncycastle.math.raw.Nat256; |
| |
| public class SecT193Field |
| { |
| private static final long M01 = 1L; |
| private static final long M49 = -1L >>> 15; |
| |
| public static void add(long[] x, long[] y, long[] z) |
| { |
| z[0] = x[0] ^ y[0]; |
| z[1] = x[1] ^ y[1]; |
| z[2] = x[2] ^ y[2]; |
| z[3] = x[3] ^ y[3]; |
| } |
| |
| public static void addExt(long[] xx, long[] yy, long[] 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]; |
| zz[5] = xx[5] ^ yy[5]; |
| zz[6] = xx[6] ^ yy[6]; |
| } |
| |
| public static void addOne(long[] x, long[] z) |
| { |
| z[0] = x[0] ^ 1L; |
| z[1] = x[1]; |
| z[2] = x[2]; |
| z[3] = x[3]; |
| } |
| |
| public static long[] fromBigInteger(BigInteger x) |
| { |
| long[] z = Nat256.fromBigInteger64(x); |
| reduce63(z, 0); |
| return z; |
| } |
| |
| public static void invert(long[] x, long[] z) |
| { |
| if (Nat256.isZero64(x)) |
| { |
| throw new IllegalStateException(); |
| } |
| |
| // Itoh-Tsujii inversion with bases { 2, 3 } |
| |
| long[] t0 = Nat256.create64(); |
| long[] t1 = Nat256.create64(); |
| |
| square(x, t0); |
| |
| // 3 | 192 |
| squareN(t0, 1, t1); |
| multiply(t0, t1, t0); |
| squareN(t1, 1, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 64 |
| squareN(t0, 3, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 32 |
| squareN(t0, 6, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 16 |
| squareN(t0, 12, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 8 |
| squareN(t0, 24, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 4 |
| squareN(t0, 48, t1); |
| multiply(t0, t1, t0); |
| |
| // 2 | 2 |
| squareN(t0, 96, t1); |
| multiply(t0, t1, z); |
| } |
| |
| public static void multiply(long[] x, long[] y, long[] z) |
| { |
| long[] tt = Nat256.createExt64(); |
| implMultiply(x, y, tt); |
| reduce(tt, z); |
| } |
| |
| public static void multiplyAddToExt(long[] x, long[] y, long[] zz) |
| { |
| long[] tt = Nat256.createExt64(); |
| implMultiply(x, y, tt); |
| addExt(zz, tt, zz); |
| } |
| |
| public static void reduce(long[] xx, long[] z) |
| { |
| long x0 = xx[0], x1 = xx[1], x2 = xx[2], x3 = xx[3], x4 = xx[4], x5 = xx[5], x6 = xx[6]; |
| |
| x2 ^= (x6 << 63); |
| x3 ^= (x6 >>> 1) ^ (x6 << 14); |
| x4 ^= (x6 >>> 50); |
| |
| x1 ^= (x5 << 63); |
| x2 ^= (x5 >>> 1) ^ (x5 << 14); |
| x3 ^= (x5 >>> 50); |
| |
| x0 ^= (x4 << 63); |
| x1 ^= (x4 >>> 1) ^ (x4 << 14); |
| x2 ^= (x4 >>> 50); |
| |
| long t = x3 >>> 1; |
| z[0] = x0 ^ t ^ (t << 15); |
| z[1] = x1 ^ (t >>> 49); |
| z[2] = x2; |
| z[3] = x3 & M01; |
| } |
| |
| public static void reduce63(long[] z, int zOff) |
| { |
| long z3 = z[zOff + 3], t = z3 >>> 1; |
| z[zOff ] ^= t ^ (t << 15); |
| z[zOff + 1] ^= (t >>> 49); |
| z[zOff + 3] = z3 & M01; |
| } |
| |
| public static void sqrt(long[] x, long[] z) |
| { |
| long u0, u1; |
| u0 = Interleave.unshuffle(x[0]); u1 = Interleave.unshuffle(x[1]); |
| long e0 = (u0 & 0x00000000FFFFFFFFL) | (u1 << 32); |
| long c0 = (u0 >>> 32) | (u1 & 0xFFFFFFFF00000000L); |
| |
| u0 = Interleave.unshuffle(x[2]); |
| long e1 = (u0 & 0x00000000FFFFFFFFL) ^ (x[3] << 32); |
| long c1 = (u0 >>> 32); |
| |
| z[0] = e0 ^ (c0 << 8); |
| z[1] = e1 ^ (c1 << 8) ^ (c0 >>> 56) ^ (c0 << 33); |
| z[2] = (c1 >>> 56) ^ (c1 << 33) ^ (c0 >>> 31); |
| z[3] = (c1 >>> 31); |
| } |
| |
| public static void square(long[] x, long[] z) |
| { |
| long[] tt = Nat256.createExt64(); |
| implSquare(x, tt); |
| reduce(tt, z); |
| } |
| |
| public static void squareAddToExt(long[] x, long[] zz) |
| { |
| long[] tt = Nat256.createExt64(); |
| implSquare(x, tt); |
| addExt(zz, tt, zz); |
| } |
| |
| public static void squareN(long[] x, int n, long[] z) |
| { |
| // assert n > 0; |
| |
| long[] tt = Nat256.createExt64(); |
| implSquare(x, tt); |
| reduce(tt, z); |
| |
| while (--n > 0) |
| { |
| implSquare(z, tt); |
| reduce(tt, z); |
| } |
| } |
| |
| public static int trace(long[] x) |
| { |
| // Non-zero-trace bits: 0 |
| return (int)(x[0]) & 1; |
| } |
| |
| protected static void implCompactExt(long[] zz) |
| { |
| long z0 = zz[0], z1 = zz[1], z2 = zz[2], z3 = zz[3], z4 = zz[4], z5 = zz[5], z6 = zz[6], z7 = zz[7]; |
| zz[0] = z0 ^ (z1 << 49); |
| zz[1] = (z1 >>> 15) ^ (z2 << 34); |
| zz[2] = (z2 >>> 30) ^ (z3 << 19); |
| zz[3] = (z3 >>> 45) ^ (z4 << 4) |
| ^ (z5 << 53); |
| zz[4] = (z4 >>> 60) ^ (z6 << 38) |
| ^ (z5 >>> 11); |
| zz[5] = (z6 >>> 26) ^ (z7 << 23); |
| zz[6] = (z7 >>> 41); |
| zz[7] = 0; |
| } |
| |
| protected static void implExpand(long[] x, long[] z) |
| { |
| long x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3]; |
| z[0] = x0 & M49; |
| z[1] = ((x0 >>> 49) ^ (x1 << 15)) & M49; |
| z[2] = ((x1 >>> 34) ^ (x2 << 30)) & M49; |
| z[3] = ((x2 >>> 19) ^ (x3 << 45)); |
| } |
| |
| protected static void implMultiply(long[] x, long[] y, long[] zz) |
| { |
| /* |
| * "Two-level seven-way recursion" as described in "Batch binary Edwards", Daniel J. Bernstein. |
| */ |
| |
| long[] f = new long[4], g = new long[4]; |
| implExpand(x, f); |
| implExpand(y, g); |
| |
| implMulwAcc(f[0], g[0], zz, 0); |
| implMulwAcc(f[1], g[1], zz, 1); |
| implMulwAcc(f[2], g[2], zz, 2); |
| implMulwAcc(f[3], g[3], zz, 3); |
| |
| // U *= (1 - t^n) |
| for (int i = 5; i > 0; --i) |
| { |
| zz[i] ^= zz[i - 1]; |
| } |
| |
| implMulwAcc(f[0] ^ f[1], g[0] ^ g[1], zz, 1); |
| implMulwAcc(f[2] ^ f[3], g[2] ^ g[3], zz, 3); |
| |
| // V *= (1 - t^2n) |
| for (int i = 7; i > 1; --i) |
| { |
| zz[i] ^= zz[i - 2]; |
| } |
| |
| // Double-length recursion |
| { |
| long c0 = f[0] ^ f[2], c1 = f[1] ^ f[3]; |
| long d0 = g[0] ^ g[2], d1 = g[1] ^ g[3]; |
| implMulwAcc(c0 ^ c1, d0 ^ d1, zz, 3); |
| long[] t = new long[3]; |
| implMulwAcc(c0, d0, t, 0); |
| implMulwAcc(c1, d1, t, 1); |
| long t0 = t[0], t1 = t[1], t2 = t[2]; |
| zz[2] ^= t0; |
| zz[3] ^= t0 ^ t1; |
| zz[4] ^= t2 ^ t1; |
| zz[5] ^= t2; |
| } |
| |
| implCompactExt(zz); |
| } |
| |
| protected static void implMulwAcc(long x, long y, long[] z, int zOff) |
| { |
| // assert x >>> 49 == 0; |
| // assert y >>> 49 == 0; |
| |
| long[] u = new long[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; |
| |
| int j = (int)x; |
| long g, h = 0, l = u[j & 7] |
| ^ (u[(j >>> 3) & 7] << 3); |
| int k = 36; |
| do |
| { |
| j = (int)(x >>> k); |
| g = u[j & 7] |
| ^ u[(j >>> 3) & 7] << 3 |
| ^ u[(j >>> 6) & 7] << 6 |
| ^ u[(j >>> 9) & 7] << 9 |
| ^ u[(j >>> 12) & 7] << 12; |
| l ^= (g << k); |
| h ^= (g >>> -k); |
| } |
| while ((k -= 15) > 0); |
| |
| // assert h >>> 33 == 0; |
| |
| z[zOff ] ^= l & M49; |
| z[zOff + 1] ^= (l >>> 49) ^ (h << 15); |
| } |
| |
| protected static void implSquare(long[] x, long[] zz) |
| { |
| Interleave.expand64To128(x[0], zz, 0); |
| Interleave.expand64To128(x[1], zz, 2); |
| Interleave.expand64To128(x[2], zz, 4); |
| zz[6] = (x[3] & M01); |
| } |
| } |