Add classes for AEAD encryption

New classes in Java 7 for Authenicated Encryption with Additional Data
(AEAD). This allows the use of encryption modes such as Galois/Counter
Mode with performs the equivalent of MAC and encryption simultaneously
and consequently makes encryption safer to use for implementors.

Change-Id: I6302826b096044ade5f62a667dc240e3ab07b351

1 files changed, 97 insertions, 0 deletions

diff --git a/luni/src/main/java/javax/crypto/spec/GCMParameterSpec.java b/luni/src/main/java/javax/crypto/spec/GCMParameterSpec.java
new file mode 100644
index 0000000..a781697
--- /dev/null
+++ b/luni/src/main/java/javax/crypto/spec/GCMParameterSpec.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2013 The Android Open Source Project
+ *
+ * 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 javax.crypto.spec;
+
+import java.security.spec.AlgorithmParameterSpec;
+import java.util.Arrays;
+
+/**
+ * Provides a the parameters for an instance of a {@link javax.crypto.Cipher}
+ * using Galois/Counter Mode (GCM). This is an Authenticated Encryption with
+ * Associated Data (AEAD) mode for a cipher which allows you to use the
+ * {@link javax.crypto.Cipher#updateAAD(byte[])} method to provide data that is
+ * transmitted in the clear but authenticated using a cryptographic Message
+ * Authentication Code (MAC).
+ *
+ * @since 1.7
+ */
+public class GCMParameterSpec implements AlgorithmParameterSpec {
+    private final int tagLen;
+
+    private final byte[] iv;
+
+    /**
+     * Creates a new {@code GCMParameterSpec} instance from the specified
+     * Initial Vector (IV) from buffer {@code iv} and a tag length of
+     * {@code tagLen} in bits.
+     *
+     * @throws IllegalArgumentException if the specified {@code iv} is null or
+     *             {@code offset} and {@code byteCount} do not specify a valid
+     *             chunk in the specified buffer.
+     */
+    public GCMParameterSpec(int tagLen, byte[] iv) {
+        if (tagLen < 0) {
+            throw new IllegalArgumentException("tag should be a non-negative integer");
+        }
+        if (iv == null) {
+            throw new IllegalArgumentException("iv == null");
+        }
+        this.tagLen = tagLen;
+        this.iv = iv.clone();
+    }
+
+    /**
+     * Creates a new {@code GCMParameterSpec} instance with the Initial Vector
+     * (IV) of {@code byteCount} bytes from the specified buffer {@code iv}
+     * starting at {@code offset} and a tag length of {@code tagLen} in bits.
+     *
+     * @throws IllegalArgumentException if the specified {@code iv} is null or
+     *             {@code offset} and {@code byteCount} do not specify a valid
+     *             chunk in the specified buffer.
+     * @throws ArrayIndexOutOfBoundsException if {@code offset} or
+     *             {@code byteCount} are negative.
+     */
+    public GCMParameterSpec(int tagLen, byte[] iv, int offset, int byteCount) {
+        if (tagLen < 0) {
+            throw new IllegalArgumentException("tag should be a non-negative integer");
+        }
+        if (iv == null) {
+            throw new IllegalArgumentException("iv == null");
+        }
+        try {
+            Arrays.checkOffsetAndCount(iv.length, offset, byteCount);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new IllegalArgumentException(e);
+        }
+        this.tagLen = tagLen;
+        this.iv = Arrays.copyOfRange(iv, offset, offset + byteCount);
+    }
+
+    /**
+     * Returns the size of the tag in bits.
+     */
+    public int getTLen() {
+        return tagLen;
+    }
+
+    /**
+     * Returns the Initial Vector (IV) used by this parameter spec.
+     */
+    public byte[] getIV() {
+        return iv.clone();
+    }
+}