1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package org.conscrypt;
18
19import java.security.InvalidAlgorithmParameterException;
20import java.security.InvalidParameterException;
21import java.security.KeyPair;
22import java.security.KeyPairGenerator;
23import java.security.SecureRandom;
24import java.security.spec.AlgorithmParameterSpec;
25import java.security.spec.ECGenParameterSpec;
26import java.security.spec.ECParameterSpec;
27import java.util.HashMap;
28import java.util.Map;
29
30public final class OpenSSLECKeyPairGenerator extends KeyPairGenerator {
31    private static final String ALGORITHM = "EC";
32
33    private static final int DEFAULT_KEY_SIZE = 192;
34
35    private static final Map<Integer, String> SIZE_TO_CURVE_NAME = new HashMap<Integer, String>();
36
37    static {
38        /* NIST curves */
39        SIZE_TO_CURVE_NAME.put(192, "prime192v1");
40        SIZE_TO_CURVE_NAME.put(224, "secp224r1");
41        SIZE_TO_CURVE_NAME.put(256, "prime256v1");
42        SIZE_TO_CURVE_NAME.put(384, "secp384r1");
43        SIZE_TO_CURVE_NAME.put(521, "secp521r1");
44    }
45
46    private OpenSSLECGroupContext group;
47
48    public OpenSSLECKeyPairGenerator() {
49        super(ALGORITHM);
50    }
51
52    @Override
53    public KeyPair generateKeyPair() {
54        if (group == null) {
55            final String curveName = SIZE_TO_CURVE_NAME.get(DEFAULT_KEY_SIZE);
56            group = OpenSSLECGroupContext.getCurveByName(curveName);
57        }
58
59        final OpenSSLKey key = new OpenSSLKey(NativeCrypto.EC_KEY_generate_key(group.getContext()));
60        return new KeyPair(new OpenSSLECPublicKey(group, key), new OpenSSLECPrivateKey(group, key));
61    }
62
63    @Override
64    public void initialize(int keysize, SecureRandom random) {
65        final String name = SIZE_TO_CURVE_NAME.get(keysize);
66        if (name == null) {
67            throw new InvalidParameterException("unknown key size " + keysize);
68        }
69
70        /*
71         * Store the group in a temporary variable until we know this is a valid
72         * group.
73         */
74        final OpenSSLECGroupContext possibleGroup = OpenSSLECGroupContext.getCurveByName(name);
75        if (possibleGroup == null) {
76            throw new InvalidParameterException("unknown curve " + name);
77        }
78
79        group = possibleGroup;
80    }
81
82    @Override
83    public void initialize(AlgorithmParameterSpec param, SecureRandom random)
84            throws InvalidAlgorithmParameterException {
85        if (param instanceof ECParameterSpec) {
86            ECParameterSpec ecParam = (ECParameterSpec) param;
87
88            group = OpenSSLECGroupContext.getInstance(ecParam);
89        } else if (param instanceof ECGenParameterSpec) {
90            ECGenParameterSpec ecParam = (ECGenParameterSpec) param;
91
92            final String curveName = ecParam.getName();
93
94            /*
95             * Store the group in a temporary variable until we know this is a
96             * valid group.
97             */
98            final OpenSSLECGroupContext possibleGroup = OpenSSLECGroupContext
99                    .getCurveByName(curveName);
100            if (possibleGroup == null) {
101                throw new InvalidAlgorithmParameterException("unknown curve name: " + curveName);
102            }
103
104            group = possibleGroup;
105        } else {
106            throw new InvalidAlgorithmParameterException(
107                    "parameter must be ECParameterSpec or ECGenParameterSpec");
108        }
109    }
110}
111