| java.lang.Object
 java.security.AlgorithmParameterGenerator
| AlgorithmParameterGenerator | | public class AlgorithmParameterGenerator (Code) | | The AlgorithmParameterGenerator class is used to generate a
set of
parameters to be used with a certain algorithm. Parameter generators
are constructed using the getInstance factory methods
(static methods that return instances of a given class).
The object that will generate the parameters can be initialized
in two different ways: in an algorithm-independent manner, or in an
algorithm-specific manner:
- The algorithm-independent approach uses the fact that all parameter
generators share the concept of a "size" and a
source of randomness. The measure of size is universally shared
by all algorithm parameters, though it is interpreted differently
for different algorithms. For example, in the case of parameters for
the DSA algorithm, "size" corresponds to the size
of the prime modulus (in bits).
When using this approach, algorithm-specific parameter generation
values - if any - default to some standard values, unless they can be
derived from the specified size.
- The other approach initializes a parameter generator object
using algorithm-specific semantics, which are represented by a set of
algorithm-specific parameter generation values. To generate
Diffie-Hellman system parameters, for example, the parameter generation
values usually
consist of the size of the prime modulus and the size of the
random exponent, both specified in number of bits.
In case the client does not explicitly initialize the
AlgorithmParameterGenerator
(via a call to an init method), each provider must supply (and
document) a default initialization. For example, the Sun provider uses a
default modulus prime size of 1024 bits for the generation of DSA
parameters.
author:
Jan Luehe
version:
1.36, 02/02/00
See Also: AlgorithmParameters
See Also: java.security.spec.AlgorithmParameterSpec
since:
1.2 |
| Method Summary | |
| final public AlgorithmParameters | generateParameters()
Generates the parameters. | | final public String | getAlgorithm()
Returns the standard name of the algorithm this parameter
generator is associated with.
the string name of the algorithm. | | public static AlgorithmParameterGenerator | getInstance(String algorithm)
Generates an AlgorithmParameterGenerator object that implements the
specified digest algorithm. | | public static AlgorithmParameterGenerator | getInstance(String algorithm, String provider)
Generates an AlgorithmParameterGenerator object for the requested
algorithm, as supplied from the specified provider,
if such a parameter generator is available from the provider.
Parameters:
algorithm - the string name of the algorithm.
Parameters:
provider - the string name of the provider. | | public static AlgorithmParameterGenerator | getInstance(String algorithm, Provider provider)
Generates an AlgorithmParameterGenerator object for the requested
algorithm, as supplied from the specified provider,
if such a parameter generator is available from the provider.
Note: the provider doesn't have to be registered. | | final public Provider | getProvider()
Returns the provider of this algorithm parameter generator object. | | final public void | init(int size)
Initializes this parameter generator for a certain size. | | final public void | init(int size, SecureRandom random)
Initializes this parameter generator for a certain size and source
of randomness. | | final public void | init(AlgorithmParameterSpec genParamSpec)
Initializes this parameter generator with a set of algorithm-specific
parameter generation values. | | final public void | init(AlgorithmParameterSpec genParamSpec, SecureRandom random)
Initializes this parameter generator with a set of algorithm-specific
parameter generation values. |
| AlgorithmParameterGenerator | | protected AlgorithmParameterGenerator(AlgorithmParameterGeneratorSpi paramGenSpi, Provider provider, String algorithm)(Code) | | Creates an AlgorithmParameterGenerator object.
Parameters:
paramGenSpi - the delegate
Parameters:
provider - the provider
Parameters:
algorithm - the algorithm |
| generateParameters | | final public AlgorithmParameters generateParameters()(Code) | | Generates the parameters.
the new AlgorithmParameters object. |
| getAlgorithm | | final public String getAlgorithm()(Code) | | Returns the standard name of the algorithm this parameter
generator is associated with.
the string name of the algorithm. |
| getInstance | | public static AlgorithmParameterGenerator getInstance(String algorithm) throws NoSuchAlgorithmException(Code) | | Generates an AlgorithmParameterGenerator object that implements the
specified digest algorithm. If the default provider package
provides an implementation of the requested digest algorithm,
an instance of AlgorithmParameterGenerator containing that
implementation
is returned. If the algorithm is not available in the default
package, other packages are searched.
Parameters:
algorithm - the string name of the algorithm thisparameter generator is associated with. the new AlgorithmParameterGenerator object.
exception:
NoSuchAlgorithmException - if the algorithm isnot available in the environment. |
| getInstance | | public static AlgorithmParameterGenerator getInstance(String algorithm, Provider provider) throws NoSuchAlgorithmException(Code) | | Generates an AlgorithmParameterGenerator object for the requested
algorithm, as supplied from the specified provider,
if such a parameter generator is available from the provider.
Note: the provider doesn't have to be registered.
Parameters:
algorithm - the string name of the algorithm.
Parameters:
provider - the provider. the new AlgorithmParameterGenerator object.
exception:
NoSuchAlgorithmException - if the algorithm isnot available from the provider.
exception:
IllegalArgumentException - if the provider isnull.
See Also: Provider
since:
1.4 |
| getProvider | | final public Provider getProvider()(Code) | | Returns the provider of this algorithm parameter generator object.
the provider of this algorithm parameter generator object |
| init | | final public void init(int size)(Code) | | Initializes this parameter generator for a certain size.
To create the parameters, the SecureRandom
implementation of the highest-priority installed provider is used as
the source of randomness.
(If none of the installed providers supply an implementation of
SecureRandom, a system-provided source of randomness is
used.)
Parameters:
size - the size (number of bits). |
| init | | final public void init(int size, SecureRandom random)(Code) | | Initializes this parameter generator for a certain size and source
of randomness.
Parameters:
size - the size (number of bits).
Parameters:
random - the source of randomness. |
| init | | final public void init(AlgorithmParameterSpec genParamSpec) throws InvalidAlgorithmParameterException(Code) | | Initializes this parameter generator with a set of algorithm-specific
parameter generation values.
To generate the parameters, the SecureRandom
implementation of the highest-priority installed provider is used as
the source of randomness.
(If none of the installed providers supply an implementation of
SecureRandom, a system-provided source of randomness is
used.)
Parameters:
genParamSpec - the set of algorithm-specific parameter generation values.
exception:
InvalidAlgorithmParameterException - if the given parametergeneration values are inappropriate for this parameter generator. |
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