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      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 
     17 package org.conscrypt;
     18 
     19 import java.security.MessageDigest;
     20 import java.security.NoSuchAlgorithmException;
     21 
     22 /**
     23  * Implements the JDK MessageDigest interface using OpenSSL's EVP API.
     24  */
     25 public class OpenSSLMessageDigestJDK extends MessageDigest implements Cloneable {
     26 
     27     /**
     28      * Holds a pointer to the native message digest context.
     29      */
     30     private long ctx;
     31 
     32     /**
     33      * Holds the EVP_MD for the hashing algorithm, e.g. EVP_get_digestbyname("sha1");
     34      */
     35     private final long evp_md;
     36 
     37     /**
     38      * Holds the output size of the message digest.
     39      */
     40     private final int size;
     41 
     42     /**
     43      * Holds a dummy buffer for writing single bytes to the digest.
     44      */
     45     private final byte[] singleByte = new byte[1];
     46 
     47     /**
     48      * Creates a new OpenSSLMessageDigest instance for the given algorithm
     49      * name.
     50      */
     51     private OpenSSLMessageDigestJDK(String algorithm, long evp_md, int size)
     52             throws NoSuchAlgorithmException {
     53         super(algorithm);
     54         this.evp_md = evp_md;
     55         this.size = size;
     56     }
     57 
     58     @Override
     59     protected void engineReset() {
     60         free();
     61     }
     62 
     63     @Override
     64     protected int engineGetDigestLength() {
     65         return size;
     66     }
     67 
     68     @Override
     69     protected void engineUpdate(byte input) {
     70         singleByte[0] = input;
     71         engineUpdate(singleByte, 0, 1);
     72     }
     73 
     74     @Override
     75     protected void engineUpdate(byte[] input, int offset, int len) {
     76         NativeCrypto.EVP_DigestUpdate(getCtx(), input, offset, len);
     77     }
     78 
     79     @Override
     80     protected byte[] engineDigest() {
     81         byte[] result = new byte[size];
     82         NativeCrypto.EVP_DigestFinal(getCtx(), result, 0);
     83         ctx = 0; // EVP_DigestFinal frees the context as a side effect
     84         return result;
     85     }
     86 
     87     public Object clone() throws CloneNotSupportedException {
     88         OpenSSLMessageDigestJDK d = (OpenSSLMessageDigestJDK) super.clone();
     89         d.ctx = NativeCrypto.EVP_MD_CTX_copy(getCtx());
     90         return d;
     91     }
     92 
     93     private long getCtx() {
     94         if (ctx == 0) {
     95             ctx = NativeCrypto.EVP_DigestInit(evp_md);
     96         }
     97         return ctx;
     98     }
     99 
    100     private void free() {
    101         if (ctx != 0) {
    102             NativeCrypto.EVP_MD_CTX_destroy(ctx);
    103             ctx = 0;
    104         }
    105     }
    106 
    107     @Override protected void finalize() throws Throwable {
    108         try {
    109             free();
    110         } finally {
    111             super.finalize();
    112         }
    113     }
    114 
    115     public static class MD5 extends OpenSSLMessageDigestJDK {
    116         private static final long EVP_MD = NativeCrypto.EVP_get_digestbyname("md5");
    117         private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
    118         public MD5() throws NoSuchAlgorithmException {
    119             super("MD5",EVP_MD, SIZE);
    120         }
    121     }
    122 
    123     public static class SHA1 extends OpenSSLMessageDigestJDK {
    124         private static final long EVP_MD = NativeCrypto.EVP_get_digestbyname("sha1");
    125         private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
    126         public SHA1() throws NoSuchAlgorithmException {
    127             super("SHA-1", EVP_MD, SIZE);
    128         }
    129     }
    130 
    131     public static class SHA256 extends OpenSSLMessageDigestJDK {
    132         private static final long EVP_MD = NativeCrypto.EVP_get_digestbyname("sha256");
    133         private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
    134         public SHA256() throws NoSuchAlgorithmException {
    135             super("SHA-256", EVP_MD, SIZE);
    136         }
    137     }
    138 
    139     public static class SHA384 extends OpenSSLMessageDigestJDK {
    140         private static final long EVP_MD = NativeCrypto.EVP_get_digestbyname("sha384");
    141         private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
    142         public SHA384() throws NoSuchAlgorithmException {
    143             super("SHA-384", EVP_MD, SIZE);
    144         }
    145     }
    146 
    147     public static class SHA512 extends OpenSSLMessageDigestJDK {
    148         private static final long EVP_MD = NativeCrypto.EVP_get_digestbyname("sha512");
    149         private static final int SIZE = NativeCrypto.EVP_MD_size(EVP_MD);
    150         public SHA512() throws NoSuchAlgorithmException {
    151             super("SHA-512", EVP_MD, SIZE);
    152         }
    153     }
    154 }
    155