ECPoint.java revision f6c387128427e121477c1b32ad35cdcaa5101ba3
1f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project/* 2f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * this work for additional information regarding copyright ownership. 5f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * (the "License"); you may not use this file except in compliance with 7f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the License. You may obtain a copy of the License at 8f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 9f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 11f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * See the License for the specific language governing permissions and 15f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * limitations under the License. 16f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 17f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 18f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectpackage java.security.spec; 19f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 20f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport java.math.BigInteger; 21f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 22f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectimport org.apache.harmony.security.internal.nls.Messages; 23f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 24f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project/** 25f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * A Point on an Elliptic Curve in barycentric (or affine) coordinates. 26f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 27f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 28f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 29f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Projectpublic class ECPoint { 30f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 31f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 32f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * The point on an Elliptic Curve at infinity. 33f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 34f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 35f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 36f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public static final ECPoint POINT_INFINITY = new ECPoint(); 37f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project // affine X coordinate of this point 38f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project private final BigInteger affineX; 39f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project // affine Y coordinate of this point 40f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project private final BigInteger affineY; 41f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 42f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project // Private ctor for POINT_INFINITY 43f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project private ECPoint() { 44f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project affineX = null; 45f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project affineY = null; 46f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 47f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 48f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 49f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Creates a new point at the specified coordinates. 50f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 51f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @param affineX 52f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the x-coordinate. 53f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @param affineY 54f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the y-coordinate. 55f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 56f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 57f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public ECPoint(BigInteger affineX, BigInteger affineY) { 58f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project this.affineX = affineX; 59f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this.affineX == null) { 60f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project throw new NullPointerException(Messages.getString("security.83", "X")); //$NON-NLS-1$ //$NON-NLS-2$ 61f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 62f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project this.affineY = affineY; 63f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this.affineY == null) { 64f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project throw new NullPointerException(Messages.getString("security.83", "Y")); //$NON-NLS-1$ //$NON-NLS-2$ 65f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 66f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 67f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 68f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 69f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Returns the x-coordinate. 70f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 71f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return the x-coordinate, or {@code null} for the infinite point. 72f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 73f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 74f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public BigInteger getAffineX() { 75f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return affineX; 76f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 77f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 78f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 79f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Returns the y-coordinate. 80f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 81f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return the y-coordinate, or {@code null} fot the infinite point. 82f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 83f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 84f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public BigInteger getAffineY() { 85f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return affineY; 86f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 87f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 88f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 89f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Returns whether the specified object and this elliptic curve point are 90f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * equal. 91f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 92f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @param other 93f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * the object to compare. 94f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return {@code true} if the specified object and this elliptic curve 95f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * point are equal, otherwise {@code false}. 96f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 97f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 98f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public boolean equals(Object other) { 99f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this == other) { 100f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return true; 101f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 102f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (other instanceof ECPoint) { 103f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this.affineX != null) { 104f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project ECPoint otherPoint = (ECPoint)other; 105f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project // no need to check for null in this case 106f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return this.affineX.equals(otherPoint.affineX) && 107f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project this.affineY.equals(otherPoint.affineY); 108f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } else { 109f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return other == POINT_INFINITY; 110f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 111f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 112f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return false; 113f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 114f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project 115f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project /** 116f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * Returns the hashcode of this elliptic curve point. 117f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * 118f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @return the hashcode of this elliptic curve point. 119f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project * @since Android 1.0 120f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project */ 121f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project public int hashCode() { 122f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project if (this.affineX != null) { 123f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return affineX.hashCode() * 31 + affineY.hashCode(); 124f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 125f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project return 11; 126f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project } 127f6c387128427e121477c1b32ad35cdcaa5101ba3The Android Open Source Project} 128