Initial import.

src/cz/cvut/keyczar/Keyczar.java

@@ -0,0 +1,153 @@
+/*
+ * Copyright 2008 Google Inc.
+ *
+ * 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 cz.cvut.keyczar;
+
+import org.apache.log4j.Logger;
+import cz.cvut.keyczar.enums.KeyPurpose;
+import cz.cvut.keyczar.enums.KeyStatus;
+import cz.cvut.keyczar.exceptions.KeyczarException;
+import cz.cvut.keyczar.i18n.Messages;
+import cz.cvut.keyczar.interfaces.EncryptedReader;
+import cz.cvut.keyczar.interfaces.KeyczarReader;
+import cz.cvut.keyczar.util.Util;
+
+import java.util.HashMap;
+
+/**
+ * Manages a Keyczar key set.
+ *
+ * @author steveweis@gmail.com (Steve Weis)
+ * @author arkajit.dey@gmail.com (Arkajit Dey)
+ *
+ */
+abstract class Keyczar {
+  static final Logger KEYCZAR_LOGGER = Logger.getLogger(Keyczar.class);
+  static final byte FORMAT_VERSION = 0;
+  static final byte[] FORMAT_BYTES = { FORMAT_VERSION };
+  static final int KEY_HASH_SIZE = 4;
+  static final int HEADER_SIZE = 1 + KEY_HASH_SIZE;
+
+  final KeyMetadata kmd;
+  KeyVersion primaryVersion;
+  final HashMap<KeyVersion, KeyczarKey> versionMap =
+    new HashMap<KeyVersion, KeyczarKey>();
+  final HashMap<KeyHash, KeyczarKey> hashMap =
+    new HashMap<KeyHash, KeyczarKey>(); // keep track of used hash identifiers
+
+  private class KeyHash {
+    private byte[] data;
+
+    private KeyHash(byte[] d) {
+      if (d.length != KEY_HASH_SIZE) {
+        throw new IllegalArgumentException();
+      }
+      data = d;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+      return (o instanceof KeyHash && o.hashCode() == this.hashCode());
+    }
+
+    @Override
+    public int hashCode() {
+      return Util.toInt(data);
+    }
+  }
+
+  /**
+   * Instantiates a new Keyczar object by passing it a Keyczar reader object
+   *
+   * @param reader A KeyczarReader to read keys from
+   * @throws KeyczarException
+   */
+  public Keyczar(KeyczarReader reader) throws KeyczarException {
+    // Reads keys from the KeyczarReader
+    kmd = KeyMetadata.read(reader.getMetadata());
+    if (!isAcceptablePurpose(kmd.getPurpose())) {
+      throw new KeyczarException(
+          Messages.getString("Keyczar.UnacceptablePurpose", kmd.getPurpose()));
+    }
+
+    if (kmd.isEncrypted() && !(reader instanceof EncryptedReader)) {
+      throw new KeyczarException(
+          Messages.getString("Keyczar.NeedEncryptedReader"));
+    }
+    for (KeyVersion version : kmd.getVersions()) {
+      if (version.getStatus() == KeyStatus.PRIMARY) {
+        if (primaryVersion != null) {
+          throw new KeyczarException(
+              Messages.getString("Keyczar.SinglePrimary"));
+        }
+        primaryVersion = version;
+      }
+      KeyczarKey key = KeyczarKey.readKey(kmd.getType(),
+          reader.getKey(version.getVersionNumber()));
+      KEYCZAR_LOGGER.info(Messages.getString("Keyczar.ReadVersion", version));
+      hashMap.put(new KeyHash(key.hash()), key);
+      versionMap.put(version, key);
+    }
+  }
+
+  /**
+   * Instantiates a new Keyczar object with a KeyczarFileReader instantiated
+   * with the given file location
+   *
+   * @param fileLocation
+   * @throws KeyczarException
+   */
+  public Keyczar(String fileLocation) throws KeyczarException {
+    this(new KeyczarFileReader(fileLocation));
+  }
+
+  @Override
+  public String toString() {
+    return kmd.toString();
+  }
+
+  /**
+   * Adds a new KeyczarKey (new version) to the key store. Associates it
+   * with given version. Adds new KeyVersion to the key set.
+   *
+   * @param version KeyVersion
+   * @param key KeyczarKey
+   */
+  void addKey(KeyVersion version, KeyczarKey key) {
+    hashMap.put(new KeyHash(key.hash()), key);
+    versionMap.put(version, key);
+    kmd.addVersion(version);
+  }
+
+  KeyczarKey getPrimaryKey() {
+    if (primaryVersion == null) {
+      return null;
+    }
+    return versionMap.get(primaryVersion);
+  }
+
+  KeyczarKey getKey(byte[] hash) {
+    return hashMap.get(new KeyHash(hash));
+  }
+
+  /**
+   * Returns true if the purpose is acceptable for this key set.
+   *
+   * @param purpose
+   * @return true if the purpose is acceptable, false otherwise.
+   */
+  abstract boolean isAcceptablePurpose(KeyPurpose purpose);
+}