| /* GENERATED SOURCE. DO NOT MODIFY. */ |
| package com.android.org.bouncycastle.math.ec.custom.sec; |
| |
| import java.math.BigInteger; |
| |
| import com.android.org.bouncycastle.math.ec.ECFieldElement; |
| import com.android.org.bouncycastle.math.raw.Mod; |
| import com.android.org.bouncycastle.math.raw.Nat; |
| import com.android.org.bouncycastle.math.raw.Nat224; |
| import com.android.org.bouncycastle.util.Arrays; |
| import com.android.org.bouncycastle.util.encoders.Hex; |
| |
| /** |
| * @hide This class is not part of the Android public SDK API |
| */ |
| public class SecP224R1FieldElement extends ECFieldElement.AbstractFp |
| { |
| public static final BigInteger Q = new BigInteger(1, |
| Hex.decodeStrict("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF000000000000000000000001")); |
| |
| protected int[] x; |
| |
| public SecP224R1FieldElement(BigInteger x) |
| { |
| if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0) |
| { |
| throw new IllegalArgumentException("x value invalid for SecP224R1FieldElement"); |
| } |
| |
| this.x = SecP224R1Field.fromBigInteger(x); |
| } |
| |
| public SecP224R1FieldElement() |
| { |
| this.x = Nat224.create(); |
| } |
| |
| protected SecP224R1FieldElement(int[] x) |
| { |
| this.x = x; |
| } |
| |
| public boolean isZero() |
| { |
| return Nat224.isZero(x); |
| } |
| |
| public boolean isOne() |
| { |
| return Nat224.isOne(x); |
| } |
| |
| public boolean testBitZero() |
| { |
| return Nat224.getBit(x, 0) == 1; |
| } |
| |
| public BigInteger toBigInteger() |
| { |
| return Nat224.toBigInteger(x); |
| } |
| |
| public String getFieldName() |
| { |
| return "SecP224R1Field"; |
| } |
| |
| public int getFieldSize() |
| { |
| return Q.bitLength(); |
| } |
| |
| public ECFieldElement add(ECFieldElement b) |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.add(x, ((SecP224R1FieldElement)b).x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement addOne() |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.addOne(x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement subtract(ECFieldElement b) |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.subtract(x, ((SecP224R1FieldElement)b).x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement multiply(ECFieldElement b) |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.multiply(x, ((SecP224R1FieldElement)b).x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement divide(ECFieldElement b) |
| { |
| // return multiply(b.invert()); |
| int[] z = Nat224.create(); |
| SecP224R1Field.inv(((SecP224R1FieldElement)b).x, z); |
| SecP224R1Field.multiply(z, x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement negate() |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.negate(x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement square() |
| { |
| int[] z = Nat224.create(); |
| SecP224R1Field.square(x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| public ECFieldElement invert() |
| { |
| // return new SecP224R1FieldElement(toBigInteger().modInverse(Q)); |
| int[] z = Nat224.create(); |
| SecP224R1Field.inv(x, z); |
| return new SecP224R1FieldElement(z); |
| } |
| |
| /** |
| * return a sqrt root - the routine verifies that the calculation returns the right value - if |
| * none exists it returns null. |
| */ |
| public ECFieldElement sqrt() |
| { |
| int[] c = this.x; |
| if (Nat224.isZero(c) || Nat224.isOne(c)) |
| { |
| return this; |
| } |
| |
| int[] nc = Nat224.create(); |
| SecP224R1Field.negate(c, nc); |
| |
| int[] r = Mod.random(SecP224R1Field.P); |
| int[] t = Nat224.create(); |
| |
| if (!isSquare(c)) |
| { |
| return null; |
| } |
| |
| while (!trySqrt(nc, r, t)) |
| { |
| SecP224R1Field.addOne(r, r); |
| } |
| |
| SecP224R1Field.square(t, r); |
| |
| return Nat224.eq(c, r) ? new SecP224R1FieldElement(t) : null; |
| } |
| |
| public boolean equals(Object other) |
| { |
| if (other == this) |
| { |
| return true; |
| } |
| |
| if (!(other instanceof SecP224R1FieldElement)) |
| { |
| return false; |
| } |
| |
| SecP224R1FieldElement o = (SecP224R1FieldElement)other; |
| return Nat224.eq(x, o.x); |
| } |
| |
| public int hashCode() |
| { |
| return Q.hashCode() ^ Arrays.hashCode(x, 0, 7); |
| } |
| |
| private static boolean isSquare(int[] x) |
| { |
| int[] t1 = Nat224.create(); |
| int[] t2 = Nat224.create(); |
| Nat224.copy(x, t1); |
| |
| for (int i = 0; i < 7; ++i) |
| { |
| Nat224.copy(t1, t2); |
| SecP224R1Field.squareN(t1, 1 << i, t1); |
| SecP224R1Field.multiply(t1, t2, t1); |
| } |
| |
| SecP224R1Field.squareN(t1, 95, t1); |
| return Nat224.isOne(t1); |
| } |
| |
| private static void RM(int[] nc, int[] d0, int[] e0, int[] d1, int[] e1, int[] f1, int[] t) |
| { |
| SecP224R1Field.multiply(e1, e0, t); |
| SecP224R1Field.multiply(t, nc, t); |
| SecP224R1Field.multiply(d1, d0, f1); |
| SecP224R1Field.add(f1, t, f1); |
| SecP224R1Field.multiply(d1, e0, t); |
| Nat224.copy(f1, d1); |
| SecP224R1Field.multiply(e1, d0, e1); |
| SecP224R1Field.add(e1, t, e1); |
| SecP224R1Field.square(e1, f1); |
| SecP224R1Field.multiply(f1, nc, f1); |
| } |
| |
| private static void RP(int[] nc, int[] d1, int[] e1, int[] f1, int[] t) |
| { |
| Nat224.copy(nc, f1); |
| |
| int[] d0 = Nat224.create(); |
| int[] e0 = Nat224.create(); |
| |
| for (int i = 0; i < 7; ++i) |
| { |
| Nat224.copy(d1, d0); |
| Nat224.copy(e1, e0); |
| |
| int j = 1 << i; |
| while (--j >= 0) |
| { |
| RS(d1, e1, f1, t); |
| } |
| |
| RM(nc, d0, e0, d1, e1, f1, t); |
| } |
| } |
| |
| private static void RS(int[] d, int[] e, int[] f, int[] t) |
| { |
| SecP224R1Field.multiply(e, d, e); |
| SecP224R1Field.twice(e, e); |
| SecP224R1Field.square(d, t); |
| SecP224R1Field.add(f, t, d); |
| SecP224R1Field.multiply(f, t, f); |
| int c = Nat.shiftUpBits(7, f, 2, 0); |
| SecP224R1Field.reduce32(c, f); |
| } |
| |
| private static boolean trySqrt(int[] nc, int[] r, int[] t) |
| { |
| int[] d1 = Nat224.create(); |
| Nat224.copy(r, d1); |
| int[] e1 = Nat224.create(); |
| e1[0] = 1; |
| int[] f1 = Nat224.create(); |
| RP(nc, d1, e1, f1, t); |
| |
| int[] d0 = Nat224.create(); |
| int[] e0 = Nat224.create(); |
| |
| for (int k = 1; k < 96; ++k) |
| { |
| Nat224.copy(d1, d0); |
| Nat224.copy(e1, e0); |
| |
| RS(d1, e1, f1, t); |
| |
| if (Nat224.isZero(d1)) |
| { |
| SecP224R1Field.inv(e0, t); |
| SecP224R1Field.multiply(t, d0, t); |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| } |