src/java.base/share/classes/java/security/interfaces/DSAKeyPairGenerator.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2017, 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

@@ -30,13 +30,16 @@
 /**
  * An interface to an object capable of generating DSA key pairs.
  *
  * <p>The {@code initialize} methods may each be called any number
  * of times. If no {@code initialize} method is called on a
- * DSAKeyPairGenerator, the default is to generate 1024-bit keys, using
- * precomputed p, q and g parameters and an instance of SecureRandom as
- * the random bit source.
+ * DSAKeyPairGenerator, each provider that implements this interface
+ * should supply (and document) a default initialization. Note that
+ * defaults may vary across different providers. Additionally, the default
+ * value for a provider may change in a future version. Therefore, it is
+ * recommended to explicitly initialize the DSAKeyPairGenerator instead
+ * of relying on provider-specific defaults. 
  *
  * <p>Users wishing to indicate DSA-specific parameters, and to generate a key
  * pair suitable for use with the DSA algorithm typically
  *
  * <ol>

@@ -43,16 +46,17 @@
  *
  * <li>Get a key pair generator for the DSA algorithm by calling the
  * KeyPairGenerator {@code getInstance} method with "DSA"
  * as its argument.
  *
- * <li>Initialize the generator by casting the result to a DSAKeyPairGenerator
- * and calling one of the
- * {@code initialize} methods from this DSAKeyPairGenerator interface.
+ * <li>Check if the returned key pair generator is an instance of
+ * DSAKeyPairGenerator before casting the result to a DSAKeyPairGenerator
+ * and calling one of the {@code initialize} methods from this
+ * DSAKeyPairGenerator interface.
  *
  * <li>Generate a key pair by calling the {@code generateKeyPair}
- * method from the KeyPairGenerator class.
+ * method of the KeyPairGenerator class.
  *
  * </ol>
  *
  * <p>Note: it is not always necessary to do algorithm-specific
  * initialization for a DSA key pair generator. That is, it is not always

@@ -61,11 +65,11 @@
  * in the KeyPairGenerator
  * interface is all that is needed when you accept defaults for algorithm-specific
  * parameters.
  *
  * <p>Note: Some earlier implementations of this interface may not support
- * larger sizes of DSA parameters such as 2048 and 3072-bit.
+ * larger values of DSA parameters such as 3072-bit.
  *
  * @since 1.1
  * @see java.security.KeyPairGenerator
  */
 public interface DSAKeyPairGenerator {

@@ -95,12 +99,11 @@
      *
      * <p>If {@code genParams} is true, this method generates new
      * p, q and g parameters. If it is false, the method uses precomputed
      * parameters for the modulus length requested. If there are no
      * precomputed parameters for that modulus length, an exception will be
-     * thrown. It is guaranteed that there will always be
-     * default parameters for modulus lengths of 512 and 1024 bits.
+     * thrown.
      *
      * @param modlen the modulus length in bits. Valid values are any
      * multiple of 64 between 512 and 1024, inclusive, 2048, and 3072.
      *
      * @param random the random bit source to use to generate key bits;