File Doc Category Size Date Package
DSAKeyPairGenerator.java API Doc Java SE 6 API 3863 Tue Jun 10 00:25:48 BST 2008 java.security.interfaces

DSAKeyPairGenerator

public interface DSAKeyPairGenerator

An interface to an object capable of generating DSA key pairs.

The initialize methods may each be called any number of times. If no 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.

Users wishing to indicate DSA-specific parameters, and to generate a key pair suitable for use with the DSA algorithm typically

Get a key pair generator for the DSA algorithm by calling the KeyPairGenerator getInstance method with "DSA" as its argument.
Initialize the generator by casting the result to a DSAKeyPairGenerator and calling one of the initialize methods from this DSAKeyPairGenerator interface.
Generate a key pair by calling the generateKeyPair method from the KeyPairGenerator class.

Note: it is not always necessary to do do algorithm-specific initialization for a DSA key pair generator. That is, it is not always necessary to call an initialize method in this interface. Algorithm-independent initialization using the initialize method in the KeyPairGenerator interface is all that is needed when you accept defaults for algorithm-specific parameters.

see: java.security.KeyPairGenerator

Fields Summary
Constructors Summary
Methods Summary
public void initialize(java.security.interfaces.DSAParams params, java.security.SecureRandom random)
Initializes the key pair generator using the DSA family parameters (p,q and g) and an optional SecureRandom bit source. If a SecureRandom bit source is needed but not supplied, i.e. null, a default SecureRandom instance will be used.
param
params the parameters to use to generate the keys.
param
random the random bit source to use to generate key bits; can be null.
exception
InvalidParameterException if the params value is invalid or null.
public void initialize(int modlen, boolean genParams, java.security.SecureRandom random)
Initializes the key pair generator for a given modulus length (instead of parameters), and an optional SecureRandom bit source. If a SecureRandom bit source is needed but not supplied, i.e. null, a default SecureRandom instance will be used.
If 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.
param
modlen the modulus length in bits. Valid values are any multiple of 8 between 512 and 1024, inclusive.
param
random the random bit source to use to generate key bits; can be null.
param
genParams whether or not to generate new parameters for the modulus length requested.
exception
InvalidParameterException if modlen is not between 512 and 1024, or if genParams is false and there are no precomputed parameters for the requested modulus length.