# AlgorithmParameters

public class **AlgorithmParameters** extends [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)  
This class is used as an opaque representation of cryptographic parameters.

An `AlgorithmParameters` object for managing the parameters
for a particular algorithm can be obtained by
calling one of the `getInstance` factory methods
(static methods that return instances of a given class).

Once an `AlgorithmParameters` object is obtained, it must be
initialized via a call to `init`, using an appropriate parameter
specification or parameter encoding.

A transparent parameter specification is obtained from an
`AlgorithmParameters` object via a call to
`getParameterSpec`, and a byte encoding of the parameters is
obtained via a call to `getEncoded`.

Android provides the following `AlgorithmParameters` algorithms:

| Algorithm | Supported API Levels |
|---|---|
| AES | 1+ |
| BLOWFISH | 10+ |
| ChaCha20 | 28+ |
| DES | 1+ |
| DESede | 1+ |
| DH | 1+ |
| DSA | 1+ |
| EC | 26+ |
| GCM | 22+ |
| IES | 1-8 |
| OAEP | 1+ |
| PBEwithHmacSHA1AndAES_128 | 26+ |
| PBEwithHmacSHA1AndAES_256 | 26+ |
| PBEwithHmacSHA224AndAES_128 | 26+ |
| PBEwithHmacSHA224AndAES_256 | 26+ |
| PBEwithHmacSHA256AndAES_128 | 26+ |
| PBEwithHmacSHA256AndAES_256 | 26+ |
| PBEwithHmacSHA384AndAES_128 | 26+ |
| PBEwithHmacSHA384AndAES_256 | 26+ |
| PBEwithHmacSHA512AndAES_128 | 26+ |
| PBEwithHmacSHA512AndAES_256 | 26+ |
| PKCS12PBE | 1+ |
| PSS | 1-8,24+ |

These algorithms are described in the [AlgorithmParameters section](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/security/StandardNames.html#AlgorithmParameters) of the Java Cryptography Architecture Standard Algorithm Name Documentation.

<br />

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/AlgorithmParameterSpec.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/DSAParameterSpec.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/KeyPairGenerator.html`

### Protected Constructor Summary

|---|---|
|   | [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#AlgorithmParameters(java.security.AlgorithmParametersSpi,%20java.security.Provider,%20java.lang.String))([AlgorithmParametersSpi](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParametersSpi.html) paramSpi, [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html) provider, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm) Creates an AlgorithmParameters object. |

### Public Method Summary

|---|---|
| final [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [getAlgorithm](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getAlgorithm())() Returns the name of the algorithm associated with this parameter object. |
| final byte\[\] | [getEncoded](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getEncoded(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) format) Returns the parameters encoded in the specified scheme. |
| final byte\[\] | [getEncoded](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getEncoded())() Returns the parameters in their primary encoding format. |
| static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html) | [getInstance](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getInstance(java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm) Returns a parameter object for the specified algorithm. |
| static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html) | [getInstance](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getInstance(java.lang.String,%20java.lang.String))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) provider) Returns a parameter object for the specified algorithm. |
| static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html) | [getInstance](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getInstance(java.lang.String,%20java.security.Provider))([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm, [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html) provider) Returns a parameter object for the specified algorithm. |
| final \<T extends [AlgorithmParameterSpec](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/AlgorithmParameterSpec.html)\> T | [getParameterSpec](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getParameterSpec(java.lang.Class<T>))([Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<T\> paramSpec) Returns a (transparent) specification of this parameter object. |
| final [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html) | [getProvider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#getProvider())() Returns the provider of this parameter object. |
| final void | [init](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#init(byte[]))(byte\[\] params) Imports the specified parameters and decodes them according to the primary decoding format for parameters. |
| final void | [init](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#init(java.security.spec.AlgorithmParameterSpec))([AlgorithmParameterSpec](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/AlgorithmParameterSpec.html) paramSpec) Initializes this parameter object using the parameters specified in `paramSpec`. |
| final void | [init](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#init(byte[],%20java.lang.String))(byte\[\] params, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) format) Imports the parameters from `params` and decodes them according to the specified decoding scheme. |
| final [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html#toString())() Returns a formatted string describing the parameters. |

### Inherited Method Summary

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

## Protected Constructors

#### protected
**AlgorithmParameters**
([AlgorithmParametersSpi](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParametersSpi.html) paramSpi, [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html) provider, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm)

Creates an AlgorithmParameters object.

##### Parameters

| paramSpi | the delegate |
| provider | the provider |
| algorithm | the algorithm |
|---|---|

## Public Methods

#### public final [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)
**getAlgorithm**
()

Returns the name of the algorithm associated with this parameter object.

##### Returns

- the algorithm name.

#### public final byte\[\]
**getEncoded**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) format)

Returns the parameters encoded in the specified scheme.
If `format` is null, the
primary encoding format for parameters is used. The primary encoding
format is ASN.1, if an ASN.1 specification for these parameters
exists.

##### Parameters

| format | the name of the encoding format. |
|---|---|

##### Returns

- the parameters encoded using the specified encoding scheme.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | on encoding errors, or if this parameter object has not been initialized. |
|---|---|

#### public final byte\[\]
**getEncoded**
()

Returns the parameters in their primary encoding format.
The primary encoding format for parameters is ASN.1, if an ASN.1
specification for this type of parameters exists.

##### Returns

- the parameters encoded using their primary encoding format.

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | on encoding errors, or if this parameter object has not been initialized. |
|---|---|

#### public static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html)
**getInstance**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm)

Returns a parameter object for the specified algorithm.

This method traverses the list of registered security Providers,
starting with the most preferred Provider.
A new AlgorithmParameters object encapsulating the
AlgorithmParametersSpi implementation from the first
Provider that supports the specified algorithm is returned.

Note that the list of registered providers may be retrieved via
the `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Security.html#getProviders()` method.

The returned parameter object must be initialized via a call to
`init`, using an appropriate parameter specification or
parameter encoding.

##### Parameters

| algorithm | the name of the algorithm requested. See the AlgorithmParameters section in the [Java Cryptography Architecture Standard Algorithm Name Documentation](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/security/StandardNames.html#AlgorithmParameters) for information about standard algorithm names. |
|---|---|

##### Returns

- the new parameter object.

##### Throws

| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if no Provider supports an AlgorithmParametersSpi implementation for the specified algorithm. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html`

#### public static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html)
**getInstance**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) provider)

Returns a parameter object for the specified algorithm.

A new AlgorithmParameters object encapsulating the
AlgorithmParametersSpi 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 `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Security.html#getProviders()` method.

The returned parameter object must be initialized via a call to
`init`, using an appropriate parameter specification or
parameter encoding.

##### Parameters

| algorithm | the name of the algorithm requested. See the AlgorithmParameters section in the [Java Cryptography Architecture Standard Algorithm Name Documentation](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/security/StandardNames.html#AlgorithmParameters) for information about standard algorithm names. |
| provider | the name of the provider. |
|---|---|

##### Returns

- the new parameter object.

##### Throws

| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if an AlgorithmParametersSpi implementation for the specified algorithm is not available from the specified provider. |
| [NoSuchProviderException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchProviderException.html) | if the specified provider is not registered in the security provider list. |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the provider name is null or empty. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html`

#### public static [AlgorithmParameters](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/AlgorithmParameters.html)
**getInstance**
([String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) algorithm, [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html) provider)

Returns a parameter object for the specified algorithm.

A new AlgorithmParameters object encapsulating the
AlgorithmParametersSpi implementation from the specified Provider
object is returned. Note that the specified Provider object
does not have to be registered in the provider list.

The returned parameter object must be initialized via a call to
`init`, using an appropriate parameter specification or
parameter encoding.

##### Parameters

| algorithm | the name of the algorithm requested. See the AlgorithmParameters section in the [Java Cryptography Architecture Standard Algorithm Name Documentation](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/security/StandardNames.html#AlgorithmParameters) for information about standard algorithm names. |
| provider | the name of the provider. |
|---|---|

##### Returns

- the new parameter object.

##### Throws

| [NoSuchAlgorithmException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/NoSuchAlgorithmException.html) | if an AlgorithmParameterGeneratorSpi implementation for the specified algorithm is not available from the specified Provider object. |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) | if the provider is null. |
|---|---|

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html`

#### public final T
**getParameterSpec**
([Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<T\> paramSpec)

Returns a (transparent) specification of this parameter object.
`paramSpec` identifies the specification class in which
the parameters should be returned. It could, for example, be
`DSAParameterSpec.class`, to indicate that the
parameters should be returned in an instance of the
`DSAParameterSpec` class.

##### Parameters

| paramSpec | the specification class in which the parameters should be returned. |
|---|---|

##### Returns

- the parameter specification.

##### Throws

| [InvalidParameterSpecException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/InvalidParameterSpecException.html) | if the requested parameter specification is inappropriate for this parameter object, or if this parameter object has not been initialized. |
|---|---|

#### public final [Provider](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/Provider.html)
**getProvider**
()

Returns the provider of this parameter object.

##### Returns

- the provider of this parameter object

#### public final void
**init**
(byte\[\] params)

Imports the specified parameters and decodes them according to the
primary decoding format for parameters. The primary decoding
format for parameters is ASN.1, if an ASN.1 specification for this type
of parameters exists.

##### Parameters

| params | the encoded parameters. |
|---|---|

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | on decoding errors, or if this parameter object has already been initialized. |
|---|---|

#### public final void
**init**
([AlgorithmParameterSpec](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/AlgorithmParameterSpec.html) paramSpec)

Initializes this parameter object using the parameters
specified in `paramSpec`.

##### Parameters

| paramSpec | the parameter specification. |
|---|---|

##### Throws

| [InvalidParameterSpecException](https://developers.google.com/j2objc/javadoc/jre/reference/java/security/spec/InvalidParameterSpecException.html) | if the given parameter specification is inappropriate for the initialization of this parameter object, or if this parameter object has already been initialized. |
|---|---|

#### public final void
**init**
(byte\[\] params, [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) format)

Imports the parameters from `params` and decodes them
according to the specified decoding scheme.
If `format` is null, the
primary decoding format for parameters is used. The primary decoding
format is ASN.1, if an ASN.1 specification for these parameters
exists.

##### Parameters

| params | the encoded parameters. |
| format | the name of the decoding scheme. |
|---|---|

##### Throws

| [IOException](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/IOException.html) | on decoding errors, or if this parameter object has already been initialized. |
|---|---|

#### public final [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html)
**toString**
()

Returns a formatted string describing the parameters.

##### Returns

- a formatted string describing the parameters, or null if this parameter object has not been initialized.