diff options
Diffstat (limited to 'core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP192R1Field.java')
| -rw-r--r-- | core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP192R1Field.java | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP192R1Field.java b/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP192R1Field.java new file mode 100644 index 00000000..4188b8f8 --- /dev/null +++ b/core/src/main/java/org/spongycastle/math/ec/custom/sec/SecP192R1Field.java @@ -0,0 +1,286 @@ +package org.spongycastle.math.ec.custom.sec; + +import java.math.BigInteger; + +import org.spongycastle.math.raw.Nat; +import org.spongycastle.math.raw.Nat192; + +public class SecP192R1Field +{ + private static final long M = 0xFFFFFFFFL; + + // 2^192 - 2^64 - 1 + static final int[] P = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + static final int[] PExt = new int[]{ 0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001, + 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private static final int[] PExtInv = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFE, + 0xFFFFFFFF, 0x00000001, 0x00000000, 0x00000002 }; + private static final int P5 = 0xFFFFFFFF; + private static final int PExt11 = 0xFFFFFFFF; + + public static void add(int[] x, int[] y, int[] z) + { + int c = Nat192.add(x, y, z); + if (c != 0 || (z[5] == P5 && Nat192.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void addExt(int[] xx, int[] yy, int[] zz) + { + int c = Nat.add(12, xx, yy, zz); + if (c != 0 || (zz[11] == PExt11 && Nat.gte(12, zz, PExt))) + { + if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0) + { + Nat.incAt(12, zz, PExtInv.length); + } + } + } + + public static void addOne(int[] x, int[] z) + { + int c = Nat.inc(6, x, z); + if (c != 0 || (z[5] == P5 && Nat192.gte(z, P))) + { + addPInvTo(z); + } + } + + public static int[] fromBigInteger(BigInteger x) + { + int[] z = Nat192.fromBigInteger(x); + if (z[5] == P5 && Nat192.gte(z, P)) + { + Nat192.subFrom(P, z); + } + return z; + } + + public static void half(int[] x, int[] z) + { + if ((x[0] & 1) == 0) + { + Nat.shiftDownBit(6, x, 0, z); + } + else + { + int c = Nat192.add(x, P, z); + Nat.shiftDownBit(6, z, c); + } + } + + public static void multiply(int[] x, int[] y, int[] z) + { + int[] tt = Nat192.createExt(); + Nat192.mul(x, y, tt); + reduce(tt, z); + } + + public static void multiplyAddToExt(int[] x, int[] y, int[] zz) + { + int c = Nat192.mulAddTo(x, y, zz); + if (c != 0 || (zz[11] == PExt11 && Nat.gte(12, zz, PExt))) + { + if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0) + { + Nat.incAt(12, zz, PExtInv.length); + } + } + } + + public static void negate(int[] x, int[] z) + { + if (Nat192.isZero(x)) + { + Nat192.zero(z); + } + else + { + Nat192.sub(P, x, z); + } + } + + public static void reduce(int[] xx, int[] z) + { + long xx06 = xx[6] & M, xx07 = xx[7] & M, xx08 = xx[8] & M; + long xx09 = xx[9] & M, xx10 = xx[10] & M, xx11 = xx[11] & M; + + long t0 = xx06 + xx10; + long t1 = xx07 + xx11; + + long cc = 0; + cc += (xx[0] & M) + t0; + int z0 = (int)cc; + cc >>= 32; + cc += (xx[1] & M) + t1; + z[1] = (int)cc; + cc >>= 32; + + t0 += xx08; + t1 += xx09; + + cc += (xx[2] & M) + t0; + long z2 = cc & M; + cc >>= 32; + cc += (xx[3] & M) + t1; + z[3] = (int)cc; + cc >>= 32; + + t0 -= xx06; + t1 -= xx07; + + cc += (xx[4] & M) + t0; + z[4] = (int)cc; + cc >>= 32; + cc += (xx[5] & M) + t1; + z[5] = (int)cc; + cc >>= 32; + + z2 += cc; + + cc += (z0 & M); + z[0] = (int)cc; + cc >>= 32; + if (cc != 0) + { + cc += (z[1] & M); + z[1] = (int)cc; + z2 += cc >> 32; + } + z[2] = (int)z2; + cc = z2 >> 32; + +// assert cc == 0 || cc == 1; + + if ((cc != 0 && Nat.incAt(6, z, 3) != 0) + || (z[5] == P5 && Nat192.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void reduce32(int x, int[] z) + { + long cc = 0; + + if (x != 0) + { + long xx06 = x & M; + + cc += (z[0] & M) + xx06; + z[0] = (int)cc; + cc >>= 32; + if (cc != 0) + { + cc += (z[1] & M); + z[1] = (int)cc; + cc >>= 32; + } + cc += (z[2] & M) + xx06; + z[2] = (int)cc; + cc >>= 32; + +// assert cc == 0 || cc == 1; + } + + if ((cc != 0 && Nat.incAt(6, z, 3) != 0) + || (z[5] == P5 && Nat192.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void square(int[] x, int[] z) + { + int[] tt = Nat192.createExt(); + Nat192.square(x, tt); + reduce(tt, z); + } + + public static void squareN(int[] x, int n, int[] z) + { +// assert n > 0; + + int[] tt = Nat192.createExt(); + Nat192.square(x, tt); + reduce(tt, z); + + while (--n > 0) + { + Nat192.square(z, tt); + reduce(tt, z); + } + } + + public static void subtract(int[] x, int[] y, int[] z) + { + int c = Nat192.sub(x, y, z); + if (c != 0) + { + subPInvFrom(z); + } + } + + public static void subtractExt(int[] xx, int[] yy, int[] zz) + { + int c = Nat.sub(12, xx, yy, zz); + if (c != 0) + { + if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0) + { + Nat.decAt(12, zz, PExtInv.length); + } + } + } + + public static void twice(int[] x, int[] z) + { + int c = Nat.shiftUpBit(6, x, 0, z); + if (c != 0 || (z[5] == P5 && Nat192.gte(z, P))) + { + addPInvTo(z); + } + } + + private static void addPInvTo(int[] z) + { + long c = (z[0] & M) + 1; + z[0] = (int)c; + c >>= 32; + if (c != 0) + { + c += (z[1] & M); + z[1] = (int)c; + c >>= 32; + } + c += (z[2] & M) + 1; + z[2] = (int)c; + c >>= 32; + if (c != 0) + { + Nat.incAt(6, z, 3); + } + } + + private static void subPInvFrom(int[] z) + { + long c = (z[0] & M) - 1; + z[0] = (int)c; + c >>= 32; + if (c != 0) + { + c += (z[1] & M); + z[1] = (int)c; + c >>= 32; + } + c += (z[2] & M) - 1; + z[2] = (int)c; + c >>= 32; + if (c != 0) + { + Nat.decAt(6, z, 3); + } + } +} |