1 /* 2 * @(#)DSAKeyPairGenerator.java 1.13 03/12/19 3 * 4 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 5 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. 6 */ 7 8 package java.security.interfaces; 9 10 import java.security.*; 11 12 /** 13 * An interface to an object capable of generating DSA key pairs. 14 * 15 * <p>The <code>initialize</code> methods may each be called any number 16 * of times. If no <code>initialize</code> method is called on a 17 * DSAKeyPairGenerator, the default is to generate 1024-bit keys, using 18 * precomputed p, q and g parameters and an instance of SecureRandom as 19 * the random bit source. 20 * 21 * <p>Users wishing to indicate DSA-specific parameters, and to generate a key 22 * pair suitable for use with the DSA algorithm typically 23 * 24 * <ol> 25 * 26 * <li>Get a key pair generator for the DSA algorithm by calling the 27 * KeyPairGenerator <code>getInstance</code> method with "DSA" 28 * as its argument.<p> 29 * 30 * <li>Initialize the generator by casting the result to a DSAKeyPairGenerator 31 * and calling one of the 32 * <code>initialize</code> methods from this DSAKeyPairGenerator interface.<p> 33 * 34 * <li>Generate a key pair by calling the <code>generateKeyPair</code> 35 * method from the KeyPairGenerator class. 36 * 37 * </ol> 38 * 39 * <p>Note: it is not always necessary to do do algorithm-specific 40 * initialization for a DSA key pair generator. That is, it is not always 41 * necessary to call an <code>initialize</code> method in this interface. 42 * Algorithm-independent initialization using the <code>initialize</code> method 43 * in the KeyPairGenerator 44 * interface is all that is needed when you accept defaults for algorithm-specific 45 * parameters. 46 * 47 * @see java.security.KeyPairGenerator 48 */ 49 public interface DSAKeyPairGenerator { 50 51 /** 52 * Initializes the key pair generator using p, q and g, the DSA 53 * family parameters. 54 * 55 * @param params the parameters to use to generate the keys. 56 * 57 * @param random the random bit source to use to generate 58 * key bits. 59 * 60 * @exception InvalidParameterException if the parameters passed are 61 * invalid or null. 62 */ 63 public void initialize(DSAParams params, SecureRandom random) 64 throws InvalidParameterException; 65 66 /** 67 * Initializes the key pair generator for a given modulus length, 68 * without parameters. 69 * 70 * <p>If <code>genParams</code> is true, this method will generate new 71 * p, q and g parameters. If it is false, the method will use precomputed 72 * parameters for the modulus length requested. If there are no 73 * precomputed parameters for that modulus length, an exception will be 74 * thrown. It is guaranteed that there will always be 75 * default parameters for modulus lengths of 512 and 1024 bits. 76 * 77 * @param modlen the modulus length, in bits. Valid values are any 78 * multiple of 8 between 512 and 1024, inclusive. 79 * 80 * @param random the random bit source to use to generate 81 * key bits. 82 * 83 * @param genParams whether or not to generate new parameters for 84 * the modulus length requested. 85 * 86 * @exception InvalidParameterException if the modulus length is not 87 * between 512 and 1024, or if genParams is false and there are 88 * not precomputed parameters for the modulus length requested. 89 */ 90 public void initialize(int modlen, boolean genParams, SecureRandom random) 91 throws InvalidParameterException; 92 } 93