--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/security/spec/EllipticCurve.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.security.spec;
+
+import java.math.BigInteger;
+import java.util.Arrays;
+
+/**
+ * This immutable class holds the necessary values needed to represent
+ * an elliptic curve.
+ *
+ * @see ECField
+ * @see ECFieldFp
+ * @see ECFieldF2m
+ *
+ * @author Valerie Peng
+ *
+ * @since 1.5
+ */
+public class EllipticCurve {
+
+ private final ECField field;
+ private final BigInteger a;
+ private final BigInteger b;
+ private final byte[] seed;
+
+ // Check coefficient c is a valid element in ECField field.
+ private static void checkValidity(ECField field, BigInteger c,
+ String cName) {
+ // can only perform check if field is ECFieldFp or ECFieldF2m.
+ if (field instanceof ECFieldFp) {
+ BigInteger p = ((ECFieldFp)field).getP();
+ if (p.compareTo(c) != 1) {
+ throw new IllegalArgumentException(cName + " is too large");
+ } else if (c.signum() < 0) {
+ throw new IllegalArgumentException(cName + " is negative");
+ }
+ } else if (field instanceof ECFieldF2m) {
+ int m = ((ECFieldF2m)field).getM();
+ if (c.bitLength() > m) {
+ throw new IllegalArgumentException(cName + " is too large");
+ }
+ }
+ }
+
+ /**
+ * Creates an elliptic curve with the specified elliptic field
+ * {@code field} and the coefficients {@code a} and
+ * {@code b}.
+ * @param field the finite field that this elliptic curve is over.
+ * @param a the first coefficient of this elliptic curve.
+ * @param b the second coefficient of this elliptic curve.
+ * @exception NullPointerException if {@code field},
+ * {@code a}, or {@code b} is null.
+ * @exception IllegalArgumentException if {@code a}
+ * or {@code b} is not null and not in {@code field}.
+ */
+ public EllipticCurve(ECField field, BigInteger a,
+ BigInteger b) {
+ this(field, a, b, null);
+ }
+
+ /**
+ * Creates an elliptic curve with the specified elliptic field
+ * {@code field}, the coefficients {@code a} and
+ * {@code b}, and the {@code seed} used for curve generation.
+ * @param field the finite field that this elliptic curve is over.
+ * @param a the first coefficient of this elliptic curve.
+ * @param b the second coefficient of this elliptic curve.
+ * @param seed the bytes used during curve generation for later
+ * validation. Contents of this array are copied to protect against
+ * subsequent modification.
+ * @exception NullPointerException if {@code field},
+ * {@code a}, or {@code b} is null.
+ * @exception IllegalArgumentException if {@code a}
+ * or {@code b} is not null and not in {@code field}.
+ */
+ public EllipticCurve(ECField field, BigInteger a,
+ BigInteger b, byte[] seed) {
+ if (field == null) {
+ throw new NullPointerException("field is null");
+ }
+ if (a == null) {
+ throw new NullPointerException("first coefficient is null");
+ }
+ if (b == null) {
+ throw new NullPointerException("second coefficient is null");
+ }
+ checkValidity(field, a, "first coefficient");
+ checkValidity(field, b, "second coefficient");
+ this.field = field;
+ this.a = a;
+ this.b = b;
+ if (seed != null) {
+ this.seed = seed.clone();
+ } else {
+ this.seed = null;
+ }
+ }
+
+ /**
+ * Returns the finite field {@code field} that this
+ * elliptic curve is over.
+ * @return the field {@code field} that this curve
+ * is over.
+ */
+ public ECField getField() {
+ return field;
+ }
+
+ /**
+ * Returns the first coefficient {@code a} of the
+ * elliptic curve.
+ * @return the first coefficient {@code a}.
+ */
+ public BigInteger getA() {
+ return a;
+ }
+
+ /**
+ * Returns the second coefficient {@code b} of the
+ * elliptic curve.
+ * @return the second coefficient {@code b}.
+ */
+ public BigInteger getB() {
+ return b;
+ }
+
+ /**
+ * Returns the seeding bytes {@code seed} used
+ * during curve generation. May be null if not specified.
+ * @return the seeding bytes {@code seed}. A new
+ * array is returned each time this method is called.
+ */
+ public byte[] getSeed() {
+ if (seed == null) return null;
+ else return seed.clone();
+ }
+
+ /**
+ * Compares this elliptic curve for equality with the
+ * specified object.
+ * @param obj the object to be compared.
+ * @return true if {@code obj} is an instance of
+ * EllipticCurve and the field, A, and B match, false otherwise.
+ */
+ public boolean equals(Object obj) {
+ if (this == obj) return true;
+ if (obj instanceof EllipticCurve) {
+ EllipticCurve curve = (EllipticCurve) obj;
+ if ((field.equals(curve.field)) &&
+ (a.equals(curve.a)) &&
+ (b.equals(curve.b))) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Returns a hash code value for this elliptic curve.
+ * @return a hash code value computed from the hash codes of the field, A,
+ * and B, as follows:
+ * <pre>{@code
+ * (field.hashCode() << 6) + (a.hashCode() << 4) + (b.hashCode() << 2)
+ * }</pre>
+ */
+ public int hashCode() {
+ return (field.hashCode() << 6 +
+ (a.hashCode() << 4) +
+ (b.hashCode() << 2));
+ }
+}