implement cipher api

scm-webapp/src/main/java/sonia/scm/security/DefaultCipherHandler.java

@@ -0,0 +1,329 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. Neither the name of SCM-Manager; nor the names of its
+ *    contributors may be used to endorse or promote products derived from this
+ *    software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.security;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.inject.Inject;
+
+import com.google.inject.Singleton;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import sonia.scm.SCMContextProvider;
+import sonia.scm.util.IOUtil;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import com.sun.jersey.core.util.Base64;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.UnsupportedEncodingException;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+
+import javax.crypto.SecretKey;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.PBEParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+@Singleton
+public class DefaultCipherHandler implements CipherHandler
+{
+
+  /** Field description */
+  public static final String CIPHER_TYPE = "AES/CTR/PKCS5PADDING";
+
+  /** Field description */
+  public static final String DIGEST_TYPE = "SHA-512";
+
+  /** Field description */
+  public static final String ENCODING = "UTF-8";
+
+  /** Field description */
+  private static final String CIPHERKEY_FILENAME = ".cipherkey";
+
+  /** Field description */
+  private static final char[] KEY_BASE = new char[]
+  {
+    '1', '4', '7', '3', 'F', '2', '1', 'E', '-', 'C', '4', 'C', '4', '-', '4',
+    '6', 'C', 'C', '-', '8', '7', 'F', '6', '-', '7', 'B', '4', 'F', '0', '5',
+    'E', 'C', '7', '7', '2', 'E'
+  };
+
+  /** Field description */
+  private static final String KEY_TYPE = "AES";
+
+  /** the logger for DefaultCipherHandler */
+  private static final Logger logger =
+    LoggerFactory.getLogger(DefaultCipherHandler.class);
+
+  //~--- constructors ---------------------------------------------------------
+
+  /**
+   * Constructs ...
+   *
+   *
+   * @param context
+   * @param keyGenerator
+   *
+   *
+   * @throws IOException
+   */
+  @Inject
+  public DefaultCipherHandler(SCMContextProvider context,
+                              KeyGenerator keyGenerator)
+          throws IOException
+  {
+    File configDirectory = new File(context.getBaseDirectory(), "config");
+
+    IOUtil.mkdirs(configDirectory);
+    cipherKeyFile = new File(configDirectory, CIPHERKEY_FILENAME);
+
+    if (cipherKeyFile.exists())
+    {
+      loadKey();
+    }
+    else
+    {
+      key = keyGenerator.createKey().toCharArray();
+      storeKey();
+    }
+  }
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param value
+   *
+   * @return
+   */
+  @Override
+  public String decode(String value)
+  {
+    return decode(key, value);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plainKey
+   * @param value
+   *
+   * @return
+   */
+  public String decode(char[] plainKey, String value)
+  {
+    String result = null;
+
+    try
+    {
+      byte[] encodedInput = Base64.decode(value);
+      byte[] salt = new byte[8];
+      byte[] encoded = new byte[encodedInput.length - 8];
+
+      System.arraycopy(encodedInput, 0, salt, 0, 8);
+      System.arraycopy(encodedInput, 8, encoded, 0, encodedInput.length - 8);
+
+      PBEParameterSpec parameterSpec = new PBEParameterSpec(salt, 20);
+      SecretKey secretKey = buildSecretKey(plainKey);
+      javax.crypto.Cipher cipher = javax.crypto.Cipher.getInstance(CIPHER_TYPE);
+
+      cipher.init(javax.crypto.Cipher.DECRYPT_MODE, secretKey, parameterSpec);
+
+      byte[] decoded = cipher.doFinal(encoded);
+
+      result = new String(decoded, ENCODING);
+    }
+    catch (Exception ex)
+    {
+      logger.error("could not decode string", ex);
+
+      throw new CipherException(ex);
+    }
+
+    return result;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param value
+   *
+   * @return
+   */
+  @Override
+  public String encode(String value)
+  {
+    return encode(key, value);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plainKey
+   * @param value
+   *
+   * @return
+   */
+  public String encode(char[] plainKey, String value)
+  {
+    String res = null;
+
+    try
+    {
+      byte[] salt = new byte[8];
+
+      random.nextBytes(salt);
+
+      IvParameterSpec iv = new IvParameterSpec(salt);
+      SecretKey secretKey = buildSecretKey(key);
+      javax.crypto.Cipher cipher = javax.crypto.Cipher.getInstance(CIPHER_TYPE);
+
+      cipher.init(javax.crypto.Cipher.ENCRYPT_MODE, secretKey, iv);
+
+      byte[] inputBytes = value.getBytes(ENCODING);
+      byte[] encodedInput = cipher.doFinal(inputBytes);
+      byte[] result = new byte[salt.length + encodedInput.length];
+
+      System.arraycopy(salt, 0, result, 0, 8);
+      System.arraycopy(encodedInput, 0, result, 8, result.length - 8);
+      res = new String(Base64.encode(result), ENCODING);
+    }
+    catch (Exception ex)
+    {
+      logger.error("could not encode string", ex);
+
+      throw new CipherException(ex);
+    }
+
+    return res;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param plainKey
+   *
+   * @return
+   *
+   * @throws NoSuchAlgorithmException
+   * @throws UnsupportedEncodingException
+   */
+  private SecretKey buildSecretKey(char[] plainKey)
+          throws UnsupportedEncodingException, NoSuchAlgorithmException
+  {
+    byte[] raw = new String(plainKey).getBytes(ENCODING);
+    MessageDigest digest = MessageDigest.getInstance(DIGEST_TYPE);
+
+    raw = digest.digest(raw);
+
+    return new SecretKeySpec(raw, KEY_TYPE);
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @throws IOException
+   */
+  private void loadKey() throws IOException
+  {
+    BufferedReader reader = null;
+
+    try
+    {
+      reader = new BufferedReader(new FileReader(cipherKeyFile));
+
+      String line = reader.readLine();
+
+      key = decode(KEY_BASE, line).toCharArray();
+    }
+    finally
+    {
+      IOUtil.close(reader);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @throws FileNotFoundException
+   */
+  private void storeKey() throws FileNotFoundException
+  {
+    String storeKey = encode(KEY_BASE, new String(key));
+    PrintWriter output = null;
+
+    try
+    {
+      output = new PrintWriter(cipherKeyFile);
+      output.write(storeKey);
+    }
+    finally
+    {
+      IOUtil.close(output);
+    }
+  }
+
+  //~--- fields ---------------------------------------------------------------
+
+  /** Field description */
+  private File cipherKeyFile;
+
+  /** Field description */
+  private char[] key = null;
+
+  /** Field description */
+  private SecureRandom random = new SecureRandom();
+}