1 files changed, 100 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/helper/Hashing.java b/src/main/java/org/traccar/helper/Hashing.java
new file mode 100644
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+++ b/src/main/java/org/traccar/helper/Hashing.java
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+/*
+ * Copyright 2015 Anton Tananaev (anton@traccar.org)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.traccar.helper;
+
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.PBEKeySpec;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+
+public final class Hashing {
+
+    public static final int ITERATIONS = 1000;
+    public static final int SALT_SIZE = 24;
+    public static final int HASH_SIZE = 24;
+
+    private static SecretKeyFactory factory;
+    static {
+        try {
+            factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static class HashingResult {
+
+        private final String hash;
+        private final String salt;
+
+        public HashingResult(String hash, String salt) {
+            this.hash = hash;
+            this.salt = salt;
+        }
+
+        public String getHash() {
+            return hash;
+        }
+
+        public String getSalt() {
+            return salt;
+        }
+    }
+
+    private Hashing() {
+    }
+
+    private static byte[] function(char[] password, byte[] salt) {
+        try {
+            PBEKeySpec spec = new PBEKeySpec(password, salt, ITERATIONS, HASH_SIZE * Byte.SIZE);
+            return factory.generateSecret(spec).getEncoded();
+        } catch (InvalidKeySpecException e) {
+            throw new SecurityException(e);
+        }
+    }
+
+    private static final SecureRandom RANDOM = new SecureRandom();
+
+    public static HashingResult createHash(String password) {
+        byte[] salt = new byte[SALT_SIZE];
+        RANDOM.nextBytes(salt);
+        byte[] hash = function(password.toCharArray(), salt);
+        return new HashingResult(
+                DataConverter.printHex(hash),
+                DataConverter.printHex(salt));
+    }
+
+    public static boolean validatePassword(String password, String hashHex, String saltHex) {
+        byte[] hash = DataConverter.parseHex(hashHex);
+        byte[] salt = DataConverter.parseHex(saltHex);
+        return slowEquals(hash, function(password.toCharArray(), salt));
+    }
+
+    /**
+     * Compares two byte arrays in length-constant time. This comparison method
+     * is used so that password hashes cannot be extracted from an on-line
+     * system using a timing attack and then attacked off-line.
+     */
+    private static boolean slowEquals(byte[] a, byte[] b) {
+        int diff = a.length ^ b.length;
+        for (int i = 0; i < a.length && i < b.length; i++) {
+            diff |= a[i] ^ b[i];
+        }
+        return diff == 0;
+    }
+
+}