src/java.base/share/classes/java/security/SecureRandomSpi.java

rev 13987 : 8051408: NIST SP 800-90A SecureRandom implementations

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -25,50 +25,154 @@
 
 package java.security;
 
 /**
  * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
- * for the {@code SecureRandom} class.
+ * for the {@link SecureRandom} class.
+ * <p>
  * All the abstract methods in this class must be implemented by each
  * service provider who wishes to supply the implementation
  * of a cryptographically strong pseudo-random number generator.
  *
+ * @implSpec
+ * If the {@link #SecureRandomSpi(SecureRandomInstantiateParameters)}
+ * constructor is overridden in an implementation, it will always be called
+ * whenever a {@code SecureRandom} is instantiated. Precisely, if an object is
+ * instantiated with one of {@code SecureRandom}'s {@code getInstance} methods
+ * <em>without</em> a {@link SecureRandomInstantiateParameters} parameter,
+ * the constructor will be called with a {@code null} argument and the
+ * implementation is responsible for creating its own
+ * {@code SecureRandomInstantiateParameters} parameter for use when
+ * {@link #engineGetParameters()} is called. If an object
+ * is instantiated with one of {@code SecureRandom}'s {@code getInstance}
+ * methods <em>with</em> a {@code SecureRandomInstantiateParameters} argument,
+ * the constructor will be called with that argument. The
+ * {@link #engineGetParameters()} method must not return {@code null}.
+ * <p>
+ * Otherwise, if the {@code SecureRandomSpi(SecureRandomInstantiateParameters)}
+ * constructor is not overridden in an implementation, the
+ * {@link #SecureRandomSpi()} constructor must be overridden and it will be
+ * called if an object is instantiated with one of {@code SecureRandom}'s
+ * {@code getInstance} methods <em>without</em> a
+ * {@code SecureRandomInstantiateParameters} argument. Calling one of
+ * {@code SecureRandom}'s {@code getInstance} methods <em>with</em>
+ * a {@code SecureRandomInstantiateParameters} argument will never
+ * return an instance of this implementation. The
+ * {@link #engineGetParameters()} method must return {@code null}.
  *
- * @see SecureRandom
  * @since 1.2
  */
 
 public abstract class SecureRandomSpi implements java.io.Serializable {
 
     private static final long serialVersionUID = -2991854161009191830L;
 
     /**
-     * Reseeds this random object. The given seed supplements, rather than
-     * replaces, the existing seed. Thus, repeated calls are guaranteed
-     * never to reduce randomness.
+     * Constructor without a parameter.
+     */
+    public SecureRandomSpi() {
+        // ignored
+    }
+
+    /**
+     * Constructor with a parameter.
+     *
+     * @param params the {@link SecureRandomInstantiateParameters} object.
+     *               This argument can be {@code null}.
+     * @throws IllegalArgumentException if {@code params} is
+     *         unrecognizable or unsupported by this {@code SecureRandom}
+     *
+     * @since 9
+     */
+    protected SecureRandomSpi(SecureRandomInstantiateParameters params) {
+        // ignored
+    }
+
+    /**
+     * Reseeds this random object with the given seed. The seed supplements,
+     * rather than replaces, the existing seed. Thus, repeated calls
+     * are guaranteed never to reduce randomness.
      *
      * @param seed the seed.
      */
     protected abstract void engineSetSeed(byte[] seed);
 
     /**
      * Generates a user-specified number of random bytes.
      *
-     * <p> If a call to {@code engineSetSeed} had not occurred previously,
-     * the first call to this method forces this SecureRandom implementation
-     * to seed itself.  This self-seeding will not occur if
-     * {@code engineSetSeed} was previously called.
-     *
      * @param bytes the array to be filled in with random bytes.
      */
     protected abstract void engineNextBytes(byte[] bytes);
 
     /**
+     * Generates a user-specified number of random bytes with
+     * additional parameters.
+     *
+     * @implSpec The default implementation throws
+     * an {@link UnsupportedOperationException}.
+     *
+     * @param bytes the array to be filled in with random bytes
+     * @param params additional parameters
+     * @throws UnsupportedOperationException if the implementation
+     *         has not overridden this method
+     * @throws IllegalArgumentException if {@code params} is {@code null},
+     *         unrecognizable or unsupported by this {@code SecureRandom}
+     *
+     * @since 9
+     */
+    protected void engineNextBytes(
+            byte[] bytes, SecureRandomNextBytesParameters params) {
+        throw new UnsupportedOperationException("not supported");
+    }
+
+    /**
      * Returns the given number of seed bytes.  This call may be used to
      * seed other random number generators.
      *
      * @param numBytes the number of seed bytes to generate.
      *
      * @return the seed bytes.
      */
      protected abstract byte[] engineGenerateSeed(int numBytes);
+
+    /**
+     * Reseeds this random object with entropy input read from its
+     * entropy source with additional parameters.
+     * <p>
+     * If this method is called by {@link SecureRandom#reseed()},
+     * {@code params} will be {@code null}.
+     *
+     * @implSpec The default implementation throws
+     *           an {@link UnsupportedOperationException}.
+     *
+     * @param params extra parameters, can be {@code null}.
+     * @throws UnsupportedOperationException if the implementation
+     *         has not overridden this method
+     * @throws IllegalArgumentException if {@code params} is
+     *         unrecognizable or unsupported by this {@code SecureRandom}
+     *
+     * @since 9
+     */
+    protected void engineReseed(SecureRandomReseedParameters params) {
+        throw new UnsupportedOperationException("not supported");
+    }
+
+    /**
+     * Returns the effective {@link SecureRandomInstantiateParameters}
+     * that is actually used to instantiate this {@code SecureRandom}.
+     *
+     * @implSpec The default implementation returns {@code null}.
+     *
+     * @return the parameters used in instantiation, or {@code null} if no
+     * parameters were used.
+     *
+     * @since 9
+     */
+    protected SecureRandomInstantiateParameters engineGetParameters() {
+        return null;
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName();
+    }
 }