public
class
AlgorithmParameterGenerator
extends Object
java.lang.Object | |
↳ | java.security.AlgorithmParameterGenerator |
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:
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.
Android provides the following AlgorithmParameterGenerator
algorithms:
Name | Supported (API Levels) |
---|---|
AES | 1–8 |
DES | 1–8 |
DESede | 1–8 |
DH | 1+ |
DSA | 1+ |
Protected constructors | |
---|---|
AlgorithmParameterGenerator(AlgorithmParameterGeneratorSpi paramGenSpi, Provider provider, String algorithm)
Creates an AlgorithmParameterGenerator object. |
Public methods | |
---|---|
final
AlgorithmParameters
|
generateParameters()
Generates the parameters. |
final
String
|
getAlgorithm()
Returns the standard name of the algorithm this parameter generator is associated with. |
static
AlgorithmParameterGenerator
|
getInstance(String algorithm)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm. |
static
AlgorithmParameterGenerator
|
getInstance(String algorithm, String provider)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm. |
static
AlgorithmParameterGenerator
|
getInstance(String algorithm, Provider provider)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm. |
final
Provider
|
getProvider()
Returns the provider of this algorithm parameter generator object. |
final
void
|
init(AlgorithmParameterSpec genParamSpec, SecureRandom random)
Initializes this parameter generator with a set of algorithm-specific parameter generation values. |
final
void
|
init(int size)
Initializes this parameter generator for a certain size. |
final
void
|
init(int size, SecureRandom random)
Initializes this parameter generator for a certain size and source of randomness. |
final
void
|
init(AlgorithmParameterSpec genParamSpec)
Initializes this parameter generator with a set of algorithm-specific parameter generation values. |
Inherited methods | |
---|---|
From
class
java.lang.Object
|
AlgorithmParameterGenerator (AlgorithmParameterGeneratorSpi paramGenSpi, Provider provider, String algorithm)
Creates an AlgorithmParameterGenerator object.
Parameters | |
---|---|
paramGenSpi |
AlgorithmParameterGeneratorSpi :
the delegate |
provider |
Provider :
the provider |
algorithm |
String :
the algorithm
|
AlgorithmParameters generateParameters ()
Generates the parameters.
Returns | |
---|---|
AlgorithmParameters |
the new AlgorithmParameters object. |
String getAlgorithm ()
Returns the standard name of the algorithm this parameter generator is associated with.
Returns | |
---|---|
String |
the string name of the algorithm. |
AlgorithmParameterGenerator getInstance (String algorithm)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm.
This method traverses the list of registered security Providers, starting with the most preferred Provider. A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the first Provider that supports the specified algorithm is returned.
Note that the list of registered providers may be retrieved via
the Security.getProviders()
method.
Parameters | |
---|---|
algorithm |
String :
the name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names. |
Returns | |
---|---|
AlgorithmParameterGenerator |
the new AlgorithmParameterGenerator object. |
Throws | |
---|---|
NoSuchAlgorithmException |
if no Provider supports an AlgorithmParameterGeneratorSpi implementation for the specified algorithm. |
See also:
AlgorithmParameterGenerator getInstance (String algorithm, String provider)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm.
A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
Note that the list of registered providers may be retrieved via
the Security.getProviders()
method.
Parameters | |
---|---|
algorithm |
String :
the name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names. |
provider |
String :
the string name of the Provider. |
Returns | |
---|---|
AlgorithmParameterGenerator |
the new AlgorithmParameterGenerator object. |
Throws | |
---|---|
NoSuchAlgorithmException |
if an AlgorithmParameterGeneratorSpi implementation for the specified algorithm is not available from the specified provider. |
NoSuchProviderException |
if the specified provider is not registered in the security provider list. |
IllegalArgumentException |
if the provider name is null or empty. |
See also:
AlgorithmParameterGenerator getInstance (String algorithm, Provider provider)
Returns an AlgorithmParameterGenerator object for generating a set of parameters to be used with the specified algorithm.
A new AlgorithmParameterGenerator object encapsulating the AlgorithmParameterGeneratorSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.
Parameters | |
---|---|
algorithm |
String :
the string name of the algorithm this
parameter generator is associated with.
See the AlgorithmParameterGenerator section in the
Java Cryptography Architecture Standard Algorithm Name Documentation
for information about standard algorithm names. |
provider |
Provider :
the Provider object. |
Returns | |
---|---|
AlgorithmParameterGenerator |
the new AlgorithmParameterGenerator object. |
Throws | |
---|---|
NoSuchAlgorithmException |
if an AlgorithmParameterGeneratorSpi implementation for the specified algorithm is not available from the specified Provider object. |
IllegalArgumentException |
if the specified provider is null. |
See also:
Provider getProvider ()
Returns the provider of this algorithm parameter generator object.
Returns | |
---|---|
Provider |
the provider of this algorithm parameter generator object |
void init (AlgorithmParameterSpec genParamSpec, SecureRandom random)
Initializes this parameter generator with a set of algorithm-specific parameter generation values.
Parameters | |
---|---|
genParamSpec |
AlgorithmParameterSpec :
the set of algorithm-specific parameter generation values. |
random |
SecureRandom :
the source of randomness. |
Throws | |
---|---|
InvalidAlgorithmParameterException |
if the given parameter generation values are inappropriate for this parameter generator. |
void init (int size)
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 |
int :
the size (number of bits).
|
void init (int size, SecureRandom random)
Initializes this parameter generator for a certain size and source of randomness.
Parameters | |
---|---|
size |
int :
the size (number of bits). |
random |
SecureRandom :
the source of randomness.
|
void init (AlgorithmParameterSpec genParamSpec)
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 |
AlgorithmParameterSpec :
the set of algorithm-specific parameter generation values. |
Throws | |
---|---|
InvalidAlgorithmParameterException |
if the given parameter generation values are inappropriate for this parameter generator. |