1 /*
2 * This file is part of dependency-check-core.
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 * Copyright (c) 2014 Jeremy Long. All Rights Reserved.
17 */
18 package org.owasp.dependencycheck.utils;
19
20 import org.slf4j.Logger;
21 import org.slf4j.LoggerFactory;
22
23 import java.io.File;
24 import java.io.FileInputStream;
25 import java.io.IOException;
26 import java.nio.MappedByteBuffer;
27 import java.nio.channels.FileChannel;
28 import java.security.MessageDigest;
29 import java.security.NoSuchAlgorithmException;
30
31 /**
32 * Includes methods to generate the MD5 and SHA1 checksum.
33 *
34 * @author Jeremy Long
35 *
36 */
37 public final class Checksum {
38
39 /**
40 * The logger.
41 */
42 private static final Logger LOGGER = LoggerFactory.getLogger(Checksum.class);
43
44 /**
45 * Private constructor for a utility class.
46 */
47 private Checksum() {
48 }
49
50 /**
51 * <p>
52 * Creates the cryptographic checksum of a given file using the specified algorithm.</p>
53 *
54 * @param algorithm the algorithm to use to calculate the checksum
55 * @param file the file to calculate the checksum for
56 * @return the checksum
57 * @throws IOException when the file does not exist
58 * @throws NoSuchAlgorithmException when an algorithm is specified that does not exist
59 */
60 public static byte[] getChecksum(String algorithm, File file) throws NoSuchAlgorithmException, IOException {
61 final MessageDigest digest = MessageDigest.getInstance(algorithm);
62 FileInputStream fis = null;
63 try {
64 fis = new FileInputStream(file);
65 final FileChannel ch = fis.getChannel();
66 long remainingToRead = file.length();
67 long start = 0;
68 while (remainingToRead > 0) {
69 long amountToRead;
70 if (remainingToRead > Integer.MAX_VALUE) {
71 remainingToRead -= Integer.MAX_VALUE;
72 amountToRead = Integer.MAX_VALUE;
73 } else {
74 amountToRead = remainingToRead;
75 remainingToRead = 0;
76 }
77 final MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, start, amountToRead);
78 digest.update(byteBuffer);
79 start += amountToRead;
80 }
81 } finally {
82 if (fis != null) {
83 try {
84 fis.close();
85 } catch (IOException ex) {
86 LOGGER.trace("Error closing file '{}'.", file.getName(), ex);
87 }
88 }
89 }
90 return digest.digest();
91 }
92
93 /**
94 * Calculates the MD5 checksum of a specified file.
95 *
96 * @param file the file to generate the MD5 checksum
97 * @return the hex representation of the MD5 hash
98 * @throws IOException when the file passed in does not exist
99 * @throws NoSuchAlgorithmException when the MD5 algorithm is not available
100 */
101 public static String getMD5Checksum(File file) throws IOException, NoSuchAlgorithmException {
102 final byte[] b = getChecksum("MD5", file);
103 return getHex(b);
104 }
105
106 /**
107 * Calculates the SHA1 checksum of a specified file.
108 *
109 * @param file the file to generate the MD5 checksum
110 * @return the hex representation of the SHA1 hash
111 * @throws IOException when the file passed in does not exist
112 * @throws NoSuchAlgorithmException when the SHA1 algorithm is not available
113 */
114 public static String getSHA1Checksum(File file) throws IOException, NoSuchAlgorithmException {
115 final byte[] b = getChecksum("SHA1", file);
116 return getHex(b);
117 }
118 /**
119 * Hex code characters used in getHex.
120 */
121 private static final String HEXES = "0123456789abcdef";
122
123 /**
124 * <p>
125 * Converts a byte array into a hex string.</p>
126 *
127 * <p>
128 * This method was copied from <a
129 * href="http://www.rgagnon.com/javadetails/java-0596.html">http://www.rgagnon.com/javadetails/java-0596.html</a></p>
130 *
131 * @param raw a byte array
132 * @return the hex representation of the byte array
133 */
134 public static String getHex(byte[] raw) {
135 if (raw == null) {
136 return null;
137 }
138 final StringBuilder hex = new StringBuilder(2 * raw.length);
139 for (final byte b : raw) {
140 hex.append(HEXES.charAt((b & 0xF0) >> 4)).append(HEXES.charAt(b & 0x0F));
141 }
142 return hex.toString();
143 }
144 }