1 /*
2 * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
37 * @since 1.5
38 */
39 public class ECPoint {
40
41 private final BigInteger x;
42 private final BigInteger y;
43
44 /**
45 * This defines the point at infinity.
46 */
47 public static final ECPoint POINT_INFINITY = new ECPoint();
48
49 // private constructor for constructing point at infinity
50 private ECPoint() {
51 this.x = null;
52 this.y = null;
53 }
54
55 /**
56 * Creates an ECPoint from the specified affine x-coordinate
57 * <code>x</code> and affine y-coordinate <code>y</code>.
58 * @param x the affine x-coordinate.
59 * @param y the affine y-coordinate.
60 * @exception NullPointerException if <code>x</code> or
61 * <code>y</code> is null.
62 */
63 public ECPoint(BigInteger x, BigInteger y) {
64 if ((x==null) || (y==null)) {
65 throw new NullPointerException("affine coordinate x or y is null");
66 }
67 this.x = x;
68 this.y = y;
69 }
70
71 /**
72 * Returns the affine x-coordinate <code>x</code>.
73 * Note: POINT_INFINITY has a null affine x-coordinate.
74 * @return the affine x-coordinate.
75 */
76 public BigInteger getAffineX() {
77 return x;
78 }
79
80 /**
81 * Returns the affine y-coordinate <code>y</code>.
82 * Note: POINT_INFINITY has a null affine y-coordinate.
83 * @return the affine y-coordinate.
84 */
85 public BigInteger getAffineY() {
86 return y;
87 }
88
89 /**
90 * Compares this elliptic curve point for equality with
91 * the specified object.
92 * @param obj the object to be compared.
93 * @return true if <code>obj</code> is an instance of
94 * ECPoint and the affine coordinates match, false otherwise.
95 */
96 public boolean equals(Object obj) {
97 if (this == obj) return true;
98 if (this == POINT_INFINITY) return false;
99 if (obj instanceof ECPoint) {
100 return ((x.equals(((ECPoint)obj).x)) &&
101 (y.equals(((ECPoint)obj).y)));
102 }
103 return false;
104 }
105
106 /**
107 * Returns a hash code value for this elliptic curve point.
108 * @return a hash code value.
109 */
110 public int hashCode() {
111 if (this == POINT_INFINITY) return 0;
112 return x.hashCode() << 5 + y.hashCode();
113 }
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1 /*
2 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
37 * @since 1.5
38 */
39 public class ECPoint {
40
41 private final BigInteger x;
42 private final BigInteger y;
43
44 /**
45 * This defines the point at infinity.
46 */
47 public static final ECPoint POINT_INFINITY = new ECPoint();
48
49 // private constructor for constructing point at infinity
50 private ECPoint() {
51 this.x = null;
52 this.y = null;
53 }
54
55 /**
56 * Creates an ECPoint from the specified affine x-coordinate
57 * {@code x} and affine y-coordinate {@code y}.
58 * @param x the affine x-coordinate.
59 * @param y the affine y-coordinate.
60 * @exception NullPointerException if {@code x} or
61 * {@code y} is null.
62 */
63 public ECPoint(BigInteger x, BigInteger y) {
64 if ((x==null) || (y==null)) {
65 throw new NullPointerException("affine coordinate x or y is null");
66 }
67 this.x = x;
68 this.y = y;
69 }
70
71 /**
72 * Returns the affine x-coordinate {@code x}.
73 * Note: POINT_INFINITY has a null affine x-coordinate.
74 * @return the affine x-coordinate.
75 */
76 public BigInteger getAffineX() {
77 return x;
78 }
79
80 /**
81 * Returns the affine y-coordinate {@code y}.
82 * Note: POINT_INFINITY has a null affine y-coordinate.
83 * @return the affine y-coordinate.
84 */
85 public BigInteger getAffineY() {
86 return y;
87 }
88
89 /**
90 * Compares this elliptic curve point for equality with
91 * the specified object.
92 * @param obj the object to be compared.
93 * @return true if {@code obj} is an instance of
94 * ECPoint and the affine coordinates match, false otherwise.
95 */
96 public boolean equals(Object obj) {
97 if (this == obj) return true;
98 if (this == POINT_INFINITY) return false;
99 if (obj instanceof ECPoint) {
100 return ((x.equals(((ECPoint)obj).x)) &&
101 (y.equals(((ECPoint)obj).y)));
102 }
103 return false;
104 }
105
106 /**
107 * Returns a hash code value for this elliptic curve point.
108 * @return a hash code value.
109 */
110 public int hashCode() {
111 if (this == POINT_INFINITY) return 0;
112 return x.hashCode() << 5 + y.hashCode();
113 }
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