diff options
Diffstat (limited to 'bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP224R1Field.java')
| -rw-r--r-- | bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP224R1Field.java | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP224R1Field.java b/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP224R1Field.java new file mode 100644 index 00000000..02a86f0f --- /dev/null +++ b/bcprov/src/main/java/org/bouncycastle/math/ec/custom/sec/SecP224R1Field.java @@ -0,0 +1,298 @@ +package org.bouncycastle.math.ec.custom.sec; + +import java.math.BigInteger; + +import org.bouncycastle.math.raw.Nat; +import org.bouncycastle.math.raw.Nat224; + +public class SecP224R1Field +{ + private static final long M = 0xFFFFFFFFL; + + // 2^224 - 2^96 + 1 + static final int[] P = new int[]{ 0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + static final int[] PExt = new int[]{ 0x00000001, 0x00000000, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, + 0xFFFFFFFF, 0x00000000, 0x00000002, 0x00000000, 0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; + private static final int[] PExtInv = new int[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000001, 0x00000000, + 0x00000000, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0x00000001 }; + private static final int P6 = 0xFFFFFFFF; + private static final int PExt13 = 0xFFFFFFFF; + + public static void add(int[] x, int[] y, int[] z) + { + int c = Nat224.add(x, y, z); + if (c != 0 || (z[6] == P6 && Nat224.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void addExt(int[] xx, int[] yy, int[] zz) + { + int c = Nat.add(14, xx, yy, zz); + if (c != 0 || (zz[13] == PExt13 && Nat.gte(14, zz, PExt))) + { + if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0) + { + Nat.incAt(14, zz, PExtInv.length); + } + } + } + + public static void addOne(int[] x, int[] z) + { + int c = Nat.inc(7, x, z); + if (c != 0 || (z[6] == P6 && Nat224.gte(z, P))) + { + addPInvTo(z); + } + } + + public static int[] fromBigInteger(BigInteger x) + { + int[] z = Nat224.fromBigInteger(x); + if (z[6] == P6 && Nat224.gte(z, P)) + { + Nat224.subFrom(P, z); + } + return z; + } + + public static void half(int[] x, int[] z) + { + if ((x[0] & 1) == 0) + { + Nat.shiftDownBit(7, x, 0, z); + } + else + { + int c = Nat224.add(x, P, z); + Nat.shiftDownBit(7, z, c); + } + } + + public static void multiply(int[] x, int[] y, int[] z) + { + int[] tt = Nat224.createExt(); + Nat224.mul(x, y, tt); + reduce(tt, z); + } + + public static void multiplyAddToExt(int[] x, int[] y, int[] zz) + { + int c = Nat224.mulAddTo(x, y, zz); + if (c != 0 || (zz[13] == PExt13 && Nat.gte(14, zz, PExt))) + { + if (Nat.addTo(PExtInv.length, PExtInv, zz) != 0) + { + Nat.incAt(14, zz, PExtInv.length); + } + } + } + + public static void negate(int[] x, int[] z) + { + if (Nat224.isZero(x)) + { + Nat224.zero(z); + } + else + { + Nat224.sub(P, x, z); + } + } + + public static void reduce(int[] xx, int[] z) + { + long xx10 = xx[10] & M, xx11 = xx[11] & M, xx12 = xx[12] & M, xx13 = xx[13] & M; + + final long n = 1; + + long t0 = (xx[7] & M) + xx11 - n; + long t1 = (xx[8] & M) + xx12; + long t2 = (xx[9] & M) + xx13; + + long cc = 0; + cc += (xx[0] & M) - t0; + long z0 = cc & M; + cc >>= 32; + cc += (xx[1] & M) - t1; + z[1] = (int)cc; + cc >>= 32; + cc += (xx[2] & M) - t2; + z[2] = (int)cc; + cc >>= 32; + cc += (xx[3] & M) + t0 - xx10; + long z3 = cc & M; + cc >>= 32; + cc += (xx[4] & M) + t1 - xx11; + z[4] = (int)cc; + cc >>= 32; + cc += (xx[5] & M) + t2 - xx12; + z[5] = (int)cc; + cc >>= 32; + cc += (xx[6] & M) + xx10 - xx13; + z[6] = (int)cc; + cc >>= 32; + cc += n; + +// assert cc >= 0; + + z3 += cc; + + z0 -= cc; + z[0] = (int)z0; + cc = z0 >> 32; + if (cc != 0) + { + cc += (z[1] & M); + z[1] = (int)cc; + cc >>= 32; + cc += (z[2] & M); + z[2] = (int)cc; + z3 += cc >> 32; + } + z[3] = (int)z3; + cc = z3 >> 32; + +// assert cc == 0 || cc == 1; + + if ((cc != 0 && Nat.incAt(7, z, 4) != 0) + || (z[6] == P6 && Nat224.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void reduce32(int x, int[] z) + { + long cc = 0; + + if (x != 0) + { + long xx07 = x & M; + + cc += (z[0] & M) - xx07; + z[0] = (int)cc; + cc >>= 32; + if (cc != 0) + { + cc += (z[1] & M); + z[1] = (int)cc; + cc >>= 32; + cc += (z[2] & M); + z[2] = (int)cc; + cc >>= 32; + } + cc += (z[3] & M) + xx07; + z[3] = (int)cc; + cc >>= 32; + +// assert cc == 0 || cc == 1; + } + + if ((cc != 0 && Nat.incAt(7, z, 4) != 0) + || (z[6] == P6 && Nat224.gte(z, P))) + { + addPInvTo(z); + } + } + + public static void square(int[] x, int[] z) + { + int[] tt = Nat224.createExt(); + Nat224.square(x, tt); + reduce(tt, z); + } + + public static void squareN(int[] x, int n, int[] z) + { +// assert n > 0; + + int[] tt = Nat224.createExt(); + Nat224.square(x, tt); + reduce(tt, z); + + while (--n > 0) + { + Nat224.square(z, tt); + reduce(tt, z); + } + } + + public static void subtract(int[] x, int[] y, int[] z) + { + int c = Nat224.sub(x, y, z); + if (c != 0) + { + subPInvFrom(z); + } + } + + public static void subtractExt(int[] xx, int[] yy, int[] zz) + { + int c = Nat.sub(14, xx, yy, zz); + if (c != 0) + { + if (Nat.subFrom(PExtInv.length, PExtInv, zz) != 0) + { + Nat.decAt(14, zz, PExtInv.length); + } + } + } + + public static void twice(int[] x, int[] z) + { + int c = Nat.shiftUpBit(7, x, 0, z); + if (c != 0 || (z[6] == P6 && Nat224.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); + z[2] = (int)c; + c >>= 32; + } + c += (z[3] & M) + 1; + z[3] = (int)c; + c >>= 32; + if (c != 0) + { + Nat.incAt(7, z, 4); + } + } + + 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); + z[2] = (int)c; + c >>= 32; + } + c += (z[3] & M) - 1; + z[3] = (int)c; + c >>= 32; + if (c != 0) + { + Nat.decAt(7, z, 4); + } + } +} |