Sleuth Kit Java Bindings (JNI)  4.12.1
Java bindings for using The Sleuth Kit
HashUtility.java
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1 /*
2  * Sleuth Kit Data Model
3  *
4  * Copyright 2011-2020 Basis Technology Corp.
5  * Contact: carrier <at> sleuthkit <dot> org
6  *
7  * Licensed under the Apache License, Version 2.0 (the "License");
8  * you may not use this file except in compliance with the License.
9  * You may obtain a copy of the License at
10  *
11  * http://www.apache.org/licenses/LICENSE-2.0
12  *
13  * Unless required by applicable law or agreed to in writing, software
14  * distributed under the License is distributed on an "AS IS" BASIS,
15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16  * See the License for the specific language governing permissions and
17  * limitations under the License.
18  */
19 package org.sleuthkit.datamodel;
20 
21 import java.io.IOException;
22 import java.security.MessageDigest;
23 import java.security.NoSuchAlgorithmException;
24 import java.util.ArrayList;
25 import java.util.Collection;
26 import java.util.List;
27 import java.util.logging.Level;
28 import java.util.logging.Logger;
29 import java.util.Map;
30 import java.util.HashMap;
31 import java.util.Arrays;
32 
36 public class HashUtility {
37 
38  private final static int BUFFER_SIZE = 16 * 1024;
39 
50  static public List<HashResult> calculateHashes(Content content, Collection<HashType> hashTypes) throws TskCoreException {
51  Map<HashType, MessageDigest> digests = new HashMap<>();
52 
53  for (HashType type : hashTypes) {
54  try {
55  digests.put(type, MessageDigest.getInstance(type.getName()));
56  } catch (NoSuchAlgorithmException ex) {
57  throw new TskCoreException("No algorithm found matching name " + type.getName(), ex);
58  }
59  }
60 
61  // Read in byte size chunks and update the hash value with the data.
62  byte[] data = new byte[BUFFER_SIZE];
63  int totalChunks = (int) Math.ceil((double) content.getSize() / (double) BUFFER_SIZE);
64  int read;
65  for (long i = 0; i < totalChunks; i++) {
66  try {
67  read = content.read(data, i * BUFFER_SIZE, BUFFER_SIZE);
68  } catch (TskCoreException ex) {
69  throw new TskCoreException("Error reading data at address " + i * BUFFER_SIZE + " from content with ID: " + content.getId(), ex);
70  }
71 
72  // Check for EOF
73  if (read == -1) {
74  break;
75  }
76 
77  // Only update with the read bytes.
78  if (read == BUFFER_SIZE) {
79  for (HashType type : hashTypes) {
80  digests.get(type).update(data);
81  }
82  } else {
83  byte[] subData = Arrays.copyOfRange(data, 0, read);
84  for (HashType type : hashTypes) {
85  digests.get(type).update(subData);
86  }
87  }
88  }
89 
90  List<HashResult> results = new ArrayList<>();
91  for (HashType type : hashTypes) {
92  byte hashData[] = digests.get(type).digest();
93  StringBuilder sb = new StringBuilder();
94  for (byte b : hashData) {
95  sb.append(String.format("%02x", b));
96  }
97  results.add(new HashResult(type, sb.toString()));
98  }
99  return results;
100  }
101 
109  public static boolean isValidMd5Hash(String md5Hash) {
110  return md5Hash.matches("^[A-Fa-f0-9]{32}$");
111  }
112 
120  public static boolean isValidSha1Hash(String sha1Hash) {
121  return sha1Hash.matches("^[A-Fa-f0-9]{40}$");
122  }
123 
131  public static boolean isValidSha256Hash(String sha256Hash) {
132  return sha256Hash.matches("^[A-Fa-f0-9]{64}$");
133  }
134 
144  public static boolean isNoDataMd5(String md5) {
145  return md5.toLowerCase().equals("d41d8cd98f00b204e9800998ecf8427e"); //NON-NLS
146  }
147 
151  public static class HashResult {
152 
153  private final HashType type;
154  private final String value;
155 
156  public HashResult(HashType type, String value) {
157  this.type = type;
158  this.value = value;
159  }
160 
161  public HashType getType() {
162  return type;
163  }
164 
165  public String getValue() {
166  return value;
167  }
168  }
169 
173  public enum HashType {
174  MD5("MD5"),
175  SHA256("SHA-256");
176 
177  private final String name; // This should be the string expected by MessageDigest
178 
179  HashType(String name) {
180  this.name = name;
181  }
182 
183  String getName() {
184  return name;
185  }
186  }
187 
200  @Deprecated
201  static public String calculateMd5(AbstractFile file) throws IOException {
202  Logger logger = Logger.getLogger(HashUtility.class.getName());
203  String md5Hash = calculateMd5Hash(file);
204  try {
205  file.getSleuthkitCase().setMd5Hash(file, md5Hash);
206  } catch (TskCoreException ex) {
207  logger.log(Level.WARNING, "Error updating content's md5 in database", ex); //NON-NLS
208  }
209  return md5Hash;
210  }
211 
223  @Deprecated
224  static public String calculateMd5Hash(Content content) throws IOException {
225  try {
226  List<HashResult> results = calculateHashes(content, Arrays.asList(HashType.MD5));
227  return results.stream()
228  .filter(result -> result.getType().equals(HashType.MD5))
229  .findFirst().get().getValue();
230 
231  } catch (TskCoreException ex) {
232  // Wrap in an IOException to retain the current method signature
233  throw new IOException(ex);
234  }
235  }
236 }
static String calculateMd5(AbstractFile file)
static boolean isNoDataMd5(String md5)
static List< HashResult > calculateHashes(Content content, Collection< HashType > hashTypes)
static boolean isValidSha256Hash(String sha256Hash)
static boolean isValidSha1Hash(String sha1Hash)
static String calculateMd5Hash(Content content)
static boolean isValidMd5Hash(String md5Hash)

Copyright © 2011-2021 Brian Carrier. (carrier -at- sleuthkit -dot- org)
This work is licensed under a Creative Commons Attribution-Share Alike 3.0 United States License.