OpenSSLDigest.java revision e6bf3e8dfa2804891a82075cb469b736321b4827 
1/*
2 * Copyright (C) 2008 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.bouncycastle.crypto.digests;
18
19import org.apache.harmony.xnet.provider.jsse.NativeCrypto;
20import org.bouncycastle.crypto.ExtendedDigest;
21
22/**
23 * Implements the BouncyCastle Digest interface using OpenSSL's EVP API.
24 */
25public class OpenSSLDigest implements ExtendedDigest {
26
27    /**
28     * Holds the standard name of the hashing algorithm, e.g. "SHA-1";
29     */
30    private final String algorithm;
31
32    /**
33     * Holds the EVP_MD for the hashing algorithm, e.g. EVP_get_digestbyname("sha1");
34     */
35    private final int evp_md;
36
37    /**
38     * Holds the output size of the message digest.
39     */
40    private final int size;
41
42    /**
43     * Holds the block size of the message digest.
44     */
45    private final int blockSize;
46
47    /**
48     * Holds a pointer to the native message digest context. It is
49     * lazily initialized to avoid having to reallocate on reset when
50     * its unlikely to be reused.
51     */
52    private int ctx;
53
54    /**
55     * Holds a dummy buffer for writing single bytes to the digest.
56     */
57    private final byte[] singleByte = new byte[1];
58
59    /**
60     * Creates a new OpenSSLMessageDigest instance for the given algorithm
61     * name.
62     */
63    private OpenSSLDigest(String algorithm, int evp_md, int size, int blockSize) {
64        this.algorithm = algorithm;
65        this.evp_md = evp_md;
66        this.size = size;
67        this.blockSize = blockSize;
68    }
69
70    public String getAlgorithmName() {
71        return algorithm;
72    }
73
74    public int getDigestSize() {
75        return size;
76    }
77
78    public int getByteLength() {
79        return blockSize;
80    }
81
82    public void reset() {
83        free();
84    }
85
86    public void update(byte in) {
87        singleByte[0] = in;
88        update(singleByte, 0, 1);
89    }
90
91    public void update(byte[] in, int inOff, int len) {
92        NativeCrypto.EVP_DigestUpdate(getCtx(), in, inOff, len);
93    }
94
95    public int doFinal(byte[] out, int outOff) {
96        int i = NativeCrypto.EVP_DigestFinal(getCtx(), out, outOff);
97        ctx = 0; // EVP_DigestFinal frees the context as a side effect
98        reset();
99        return i;
100    }
101
102    private int getCtx() {
103        if (ctx == 0) {
104            ctx = NativeCrypto.EVP_DigestInit(evp_md);
105        }
106        return ctx;
107    }
108
109    private void free() {
110        if (ctx != 0) {
111            NativeCrypto.EVP_MD_CTX_destroy(ctx);
112            ctx = 0;
113        }
114    }
115
116    @Override
117    protected void finalize() throws Throwable {
118        try {
119            free();
120        } finally {
121            super.finalize();
122        }
123    }
124
125    public static class MD5 extends OpenSSLDigest {
126        private static final int EVP_MD = NativeCrypto.EVP_get_digestbyname("md5");
127        private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
128        private static final int BLOCK_SIZE = NativeCrypto.EVP_MD_block_size(EVP_MD);
129        public MD5() { super("MD5", EVP_MD, SIZE, BLOCK_SIZE); }
130    }
131
132    public static class SHA1 extends OpenSSLDigest {
133        private static final int EVP_MD = NativeCrypto.EVP_get_digestbyname("sha1");
134        private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
135        private static final int BLOCK_SIZE = NativeCrypto.EVP_MD_block_size(EVP_MD);
136        public SHA1() { super("SHA-1", EVP_MD, SIZE, BLOCK_SIZE); }
137    }
138
139    public static class SHA256 extends OpenSSLDigest {
140        private static final int EVP_MD = NativeCrypto.EVP_get_digestbyname("sha256");
141        private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
142        private static final int BLOCK_SIZE = NativeCrypto.EVP_MD_block_size(EVP_MD);
143        public SHA256() { super("SHA-256", EVP_MD, SIZE, BLOCK_SIZE); }
144    }
145
146    public static class SHA384 extends OpenSSLDigest {
147        private static final int EVP_MD = NativeCrypto.EVP_get_digestbyname("sha384");
148        private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
149        private static final int BLOCK_SIZE = NativeCrypto.EVP_MD_block_size(EVP_MD);
150        public SHA384() { super("SHA-384", EVP_MD, SIZE, BLOCK_SIZE); }
151    }
152
153    public static class SHA512 extends OpenSSLDigest {
154        private static final int EVP_MD = NativeCrypto.EVP_get_digestbyname("sha512");
155        private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
156        private static final int BLOCK_SIZE = NativeCrypto.EVP_MD_block_size(EVP_MD);
157        public SHA512() { super("SHA-512", EVP_MD, SIZE, BLOCK_SIZE); }
158    }
159}
160