| /* 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.Nat192; |
| import com.android.org.bouncycastle.util.Arrays; |
| |
| /** |
| * @hide This class is not part of the Android public SDK API |
| */ |
| public class SecP192K1FieldElement extends ECFieldElement |
| { |
| public static final BigInteger Q = SecP192K1Curve.q; |
| |
| protected int[] x; |
| |
| public SecP192K1FieldElement(BigInteger x) |
| { |
| if (x == null || x.signum() < 0 || x.compareTo(Q) >= 0) |
| { |
| throw new IllegalArgumentException("x value invalid for SecP192K1FieldElement"); |
| } |
| |
| this.x = SecP192K1Field.fromBigInteger(x); |
| } |
| |
| public SecP192K1FieldElement() |
| { |
| this.x = Nat192.create(); |
| } |
| |
| protected SecP192K1FieldElement(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 "SecP192K1Field"; |
| } |
| |
| public int getFieldSize() |
| { |
| return Q.bitLength(); |
| } |
| |
| public ECFieldElement add(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.add(x, ((SecP192K1FieldElement)b).x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement addOne() |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.addOne(x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement subtract(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.subtract(x, ((SecP192K1FieldElement)b).x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement multiply(ECFieldElement b) |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.multiply(x, ((SecP192K1FieldElement)b).x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement divide(ECFieldElement b) |
| { |
| // return multiply(b.invert()); |
| int[] z = Nat192.create(); |
| Mod.invert(SecP192K1Field.P, ((SecP192K1FieldElement)b).x, z); |
| SecP192K1Field.multiply(z, x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement negate() |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.negate(x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement square() |
| { |
| int[] z = Nat192.create(); |
| SecP192K1Field.square(x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| public ECFieldElement invert() |
| { |
| // return new SecP192K1FieldElement(toBigInteger().modInverse(Q)); |
| int[] z = Nat192.create(); |
| Mod.invert(SecP192K1Field.P, x, z); |
| return new SecP192K1FieldElement(z); |
| } |
| |
| /** |
| * 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 - 2^30 - 2^10 - 2^6 - 2^5 - 2^4 - 2^1 |
| * |
| * Breaking up the exponent's binary representation into "repunits", we get: |
| * { 159 1s } { 1 0s } { 19 1s } { 1 0s } { 3 1s } { 3 0s} { 3 1s } { 1 0s } |
| * |
| * Therefore we need an addition chain containing 3, 19, 159 (the lengths of the repunits) |
| * We use: 1, 2, [3], 6, 8, 16, [19], 35, 70, 140, [159] |
| */ |
| |
| int[] x1 = this.x; |
| if (Nat192.isZero(x1) || Nat192.isOne(x1)) |
| { |
| return this; |
| } |
| |
| int[] x2 = Nat192.create(); |
| SecP192K1Field.square(x1, x2); |
| SecP192K1Field.multiply(x2, x1, x2); |
| int[] x3 = Nat192.create(); |
| SecP192K1Field.square(x2, x3); |
| SecP192K1Field.multiply(x3, x1, x3); |
| int[] x6 = Nat192.create(); |
| SecP192K1Field.squareN(x3, 3, x6); |
| SecP192K1Field.multiply(x6, x3, x6); |
| int[] x8 = x6; |
| SecP192K1Field.squareN(x6, 2, x8); |
| SecP192K1Field.multiply(x8, x2, x8); |
| int[] x16 = x2; |
| SecP192K1Field.squareN(x8, 8, x16); |
| SecP192K1Field.multiply(x16, x8, x16); |
| int[] x19 = x8; |
| SecP192K1Field.squareN(x16, 3, x19); |
| SecP192K1Field.multiply(x19, x3, x19); |
| int[] x35 = Nat192.create(); |
| SecP192K1Field.squareN(x19, 16, x35); |
| SecP192K1Field.multiply(x35, x16, x35); |
| int[] x70 = x16; |
| SecP192K1Field.squareN(x35, 35, x70); |
| SecP192K1Field.multiply(x70, x35, x70); |
| int[] x140 = x35; |
| SecP192K1Field.squareN(x70, 70, x140); |
| SecP192K1Field.multiply(x140, x70, x140); |
| int[] x159 = x70; |
| SecP192K1Field.squareN(x140, 19, x159); |
| SecP192K1Field.multiply(x159, x19, x159); |
| |
| int[] t1 = x159; |
| SecP192K1Field.squareN(t1, 20, t1); |
| SecP192K1Field.multiply(t1, x19, t1); |
| SecP192K1Field.squareN(t1, 4, t1); |
| SecP192K1Field.multiply(t1, x3, t1); |
| SecP192K1Field.squareN(t1, 6, t1); |
| SecP192K1Field.multiply(t1, x3, t1); |
| SecP192K1Field.square(t1, t1); |
| |
| int[] t2 = x3; |
| SecP192K1Field.square(t1, t2); |
| |
| return Nat192.eq(x1, t2) ? new SecP192K1FieldElement(t1) : null; |
| } |
| |
| public boolean equals(Object other) |
| { |
| if (other == this) |
| { |
| return true; |
| } |
| |
| if (!(other instanceof SecP192K1FieldElement)) |
| { |
| return false; |
| } |
| |
| SecP192K1FieldElement o = (SecP192K1FieldElement)other; |
| return Nat192.eq(x, o.x); |
| } |
| |
| public int hashCode() |
| { |
| return Q.hashCode() ^ Arrays.hashCode(x, 0, 6); |
| } |
| } |