| package org.bouncycastle.math.ec.custom.sec; |
| |
| import java.math.BigInteger; |
| |
| import org.bouncycastle.math.ec.ECFieldElement; |
| import org.bouncycastle.math.raw.Mod; |
| import org.bouncycastle.math.raw.Nat192; |
| import org.bouncycastle.util.Arrays; |
| |
| public class SecP192R1FieldElement extends ECFieldElement.AbstractFp |
| { |
| public static final BigInteger Q = SecP192R1Curve.q; |
| |
| protected int[] x; |
| |
| public SecP192R1FieldElement(BigInteger x) |
| { |
| if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0) |
| { |
| throw new IllegalArgumentException("x value invalid for SecP192R1FieldElement"); |
| } |
| |
| this.x = SecP192R1Field.fromBigInteger(x); |
| } |
| |
| public SecP192R1FieldElement() |
| { |
| this.x = Nat192.create(); |
| } |
| |
| protected SecP192R1FieldElement(int[] x) |
| { |
| this.x = x; |
| } |
| |
| public boolean isZero() |
| { |
| return Nat192.isZero(x); |
| } |
| |
| public boolean isOne() |
| { |
| return Nat192.isOne(x); |
| } |
| |
| public boolean testBitZero() |
| { |
| return Nat192.getBit(x, 0) == 1; |
| } |
| |
| public BigInteger toBigInteger() |
| { |
| return Nat192.toBigInteger(x); |
| } |
| |
| public String getFieldName() |
| { |
| return "SecP192R1Field"; |
| } |
| |
| public int getFieldSize() |
| { |
| return Q.bitLength(); |
| } |
| |
| public ECFieldElement add(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.add(x, ((SecP192R1FieldElement)b).x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement addOne() |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.addOne(x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement subtract(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.subtract(x, ((SecP192R1FieldElement)b).x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement multiply(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.multiply(x, ((SecP192R1FieldElement)b).x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement divide(ECFieldElement b) |
| { |
| // return multiply(b.invert()); |
| int[] z = Nat192.create(); |
| Mod.invert(SecP192R1Field.P, ((SecP192R1FieldElement)b).x, z); |
| SecP192R1Field.multiply(z, x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement negate() |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.negate(x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement square() |
| { |
| int[] z = Nat192.create(); |
| SecP192R1Field.square(x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| public ECFieldElement invert() |
| { |
| // return new SecP192R1FieldElement(toBigInteger().modInverse(Q)); |
| int[] z = Nat192.create(); |
| Mod.invert(SecP192R1Field.P, x, z); |
| return new SecP192R1FieldElement(z); |
| } |
| |
| // D.1.4 91 |
| /** |
| * return a sqrt root - the routine verifies that the calculation returns the right value - if |
| * none exists it returns null. |
| */ |
| public ECFieldElement sqrt() |
| { |
| // Raise this element to the exponent 2^190 - 2^62 |
| |
| int[] x1 = this.x; |
| if (Nat192.isZero(x1) || Nat192.isOne(x1)) |
| { |
| return this; |
| } |
| |
| int[] t1 = Nat192.create(); |
| int[] t2 = Nat192.create(); |
| |
| SecP192R1Field.square(x1, t1); |
| SecP192R1Field.multiply(t1, x1, t1); |
| |
| SecP192R1Field.squareN(t1, 2, t2); |
| SecP192R1Field.multiply(t2, t1, t2); |
| |
| SecP192R1Field.squareN(t2, 4, t1); |
| SecP192R1Field.multiply(t1, t2, t1); |
| |
| SecP192R1Field.squareN(t1, 8, t2); |
| SecP192R1Field.multiply(t2, t1, t2); |
| |
| SecP192R1Field.squareN(t2, 16, t1); |
| SecP192R1Field.multiply(t1, t2, t1); |
| |
| SecP192R1Field.squareN(t1, 32, t2); |
| SecP192R1Field.multiply(t2, t1, t2); |
| |
| SecP192R1Field.squareN(t2, 64, t1); |
| SecP192R1Field.multiply(t1, t2, t1); |
| |
| SecP192R1Field.squareN(t1, 62, t1); |
| SecP192R1Field.square(t1, t2); |
| |
| return Nat192.eq(x1, t2) ? new SecP192R1FieldElement(t1) : null; |
| } |
| |
| public boolean equals(Object other) |
| { |
| if (other == this) |
| { |
| return true; |
| } |
| |
| if (!(other instanceof SecP192R1FieldElement)) |
| { |
| return false; |
| } |
| |
| SecP192R1FieldElement o = (SecP192R1FieldElement)other; |
| return Nat192.eq(x, o.x); |
| } |
| |
| public int hashCode() |
| { |
| return Q.hashCode() ^ Arrays.hashCode(x, 0, 6); |
| } |
| } |