100 lines
3.8 KiB
Java
100 lines
3.8 KiB
Java
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package org.bouncycastle.pqc.math.linearalgebra;
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/* loaded from: classes6.dex */
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public class PolynomialRingGF2m {
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private GF2mField field;
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private PolynomialGF2mSmallM p;
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protected PolynomialGF2mSmallM[] sqMatrix;
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protected PolynomialGF2mSmallM[] sqRootMatrix;
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public PolynomialGF2mSmallM[] getSquaringMatrix() {
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return this.sqMatrix;
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}
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public PolynomialGF2mSmallM[] getSquareRootMatrix() {
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return this.sqRootMatrix;
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}
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private static void swapColumns(PolynomialGF2mSmallM[] polynomialGF2mSmallMArr, int i, int i2) {
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PolynomialGF2mSmallM polynomialGF2mSmallM = polynomialGF2mSmallMArr[i];
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polynomialGF2mSmallMArr[i] = polynomialGF2mSmallMArr[i2];
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polynomialGF2mSmallMArr[i2] = polynomialGF2mSmallM;
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}
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private void computeSquaringMatrix() {
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int i;
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int degree = this.p.getDegree();
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this.sqMatrix = new PolynomialGF2mSmallM[degree];
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int i2 = 0;
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while (true) {
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i = degree >> 1;
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if (i2 >= i) {
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break;
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}
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int i3 = i2 << 1;
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int[] iArr = new int[i3 + 1];
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iArr[i3] = 1;
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this.sqMatrix[i2] = new PolynomialGF2mSmallM(this.field, iArr);
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i2++;
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}
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while (i < degree) {
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int i4 = i << 1;
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int[] iArr2 = new int[i4 + 1];
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iArr2[i4] = 1;
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this.sqMatrix[i] = new PolynomialGF2mSmallM(this.field, iArr2).mod(this.p);
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i++;
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}
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}
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private void computeSquareRootMatrix() {
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int coefficient;
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int degree = this.p.getDegree();
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PolynomialGF2mSmallM[] polynomialGF2mSmallMArr = new PolynomialGF2mSmallM[degree];
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int i = degree - 1;
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for (int i2 = i; i2 >= 0; i2--) {
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polynomialGF2mSmallMArr[i2] = new PolynomialGF2mSmallM(this.sqMatrix[i2]);
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}
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this.sqRootMatrix = new PolynomialGF2mSmallM[degree];
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while (i >= 0) {
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this.sqRootMatrix[i] = new PolynomialGF2mSmallM(this.field, i);
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i--;
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}
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for (int i3 = 0; i3 < degree; i3++) {
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if (polynomialGF2mSmallMArr[i3].getCoefficient(i3) == 0) {
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int i4 = i3 + 1;
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boolean z = false;
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while (i4 < degree) {
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if (polynomialGF2mSmallMArr[i4].getCoefficient(i3) != 0) {
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swapColumns(polynomialGF2mSmallMArr, i3, i4);
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swapColumns(this.sqRootMatrix, i3, i4);
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i4 = degree;
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z = true;
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}
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i4++;
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}
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if (!z) {
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throw new ArithmeticException("Squaring matrix is not invertible.");
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}
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}
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int inverse = this.field.inverse(polynomialGF2mSmallMArr[i3].getCoefficient(i3));
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polynomialGF2mSmallMArr[i3].multThisWithElement(inverse);
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this.sqRootMatrix[i3].multThisWithElement(inverse);
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for (int i5 = 0; i5 < degree; i5++) {
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if (i5 != i3 && (coefficient = polynomialGF2mSmallMArr[i5].getCoefficient(i3)) != 0) {
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PolynomialGF2mSmallM multWithElement = polynomialGF2mSmallMArr[i3].multWithElement(coefficient);
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PolynomialGF2mSmallM multWithElement2 = this.sqRootMatrix[i3].multWithElement(coefficient);
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polynomialGF2mSmallMArr[i5].addToThis(multWithElement);
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this.sqRootMatrix[i5].addToThis(multWithElement2);
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}
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}
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}
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}
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public PolynomialRingGF2m(GF2mField gF2mField, PolynomialGF2mSmallM polynomialGF2mSmallM) {
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this.field = gF2mField;
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this.p = polynomialGF2mSmallM;
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computeSquaringMatrix();
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computeSquareRootMatrix();
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}
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}
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