Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels) Summary: [Ctors](https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#pubctors) \| [Methods](https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#pubmethods) \| [Inherited Methods](https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#inhmethods)

# KeyPairGeneratorSpi

` public abstract class KeyPairGeneratorSpi `   
` extends https://developer.android.com/reference/java/lang/Object ` ` `

|---|---|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | java.security.KeyPairGeneratorSpi |

Known direct subclasses [KeyPairGenerator](https://developer.android.com/reference/java/security/KeyPairGenerator) [KeyPairGenerator](https://developer.android.com/reference/java/security/KeyPairGenerator) The KeyPairGenerator class is used to generate pairs of public and private keys.   

*** ** * ** ***

<br />

This class defines the *Service Provider Interface* (**SPI** ) for the `KeyPairGenerator` class, which is used to generate pairs of public and private keys.

All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a key pair generator for a particular algorithm.

In case the client does not explicitly initialize the KeyPairGenerator (via a call to an `initialize` method), each provider must supply (and document) a default initialization. For example, the *Sun* provider uses a default modulus size (keysize) of 1024 bits.
**See also:**

- `https://developer.android.com/reference/java/security/KeyPairGenerator`
- `https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec`

## Summary

| ### Public constructors ||
|---|---|
| ` https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#KeyPairGeneratorSpi()() ` |

| ### Public methods ||
|---|---|
| ` abstract https://developer.android.com/reference/java/security/KeyPair` | ` https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#generateKeyPair()() ` Generates a key pair. |
| ` void` | ` https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#initialize(java.security.spec.AlgorithmParameterSpec,%20java.security.SecureRandom)(https://developer.android.com/reference/java/security/spec/AlgorithmParameterSpec params, https://developer.android.com/reference/java/security/SecureRandom random) ` Initializes the key pair generator using the specified parameter set and user-provided source of randomness. |
| ` abstract void` | ` https://developer.android.com/reference/java/security/KeyPairGeneratorSpi#initialize(int,%20java.security.SecureRandom)(int keysize, https://developer.android.com/reference/java/security/SecureRandom random) ` Initializes the key pair generator for a certain keysize, using the default parameter set. |

### Inherited methods

From class ` https://developer.android.com/reference/java/lang/Object ` ` https://developer.android.com/reference/java/lang/Object` ` https://developer.android.com/reference/java/lang/Object#clone()() `

Creates and returns a copy of this object.
` boolean` ` https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object)(https://developer.android.com/reference/java/lang/Object obj) `

Indicates whether some other object is "equal to" this one.
` void` ` https://developer.android.com/reference/java/lang/Object#finalize()() `

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
` final https://developer.android.com/reference/java/lang/Class<?>` ` https://developer.android.com/reference/java/lang/Object#getClass()() `

Returns the runtime class of this `Object`.
` int` ` https://developer.android.com/reference/java/lang/Object#hashCode()() `

Returns a hash code value for the object.
` final void` ` https://developer.android.com/reference/java/lang/Object#notify()() `

Wakes up a single thread that is waiting on this object's monitor.
` final void` ` https://developer.android.com/reference/java/lang/Object#notifyAll()() `

Wakes up all threads that are waiting on this object's monitor.
` https://developer.android.com/reference/java/lang/String` ` https://developer.android.com/reference/java/lang/Object#toString()() `

Returns a string representation of the object.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait(long,%20int)(long timeoutMillis, int nanos) `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait(long)(long timeoutMillis) `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*, or until a certain amount of real time has elapsed.
` final void` ` https://developer.android.com/reference/java/lang/Object#wait()() `

Causes the current thread to wait until it is awakened, typically by being *notified* or *interrupted*.

## Public constructors

### KeyPairGeneratorSpi

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public KeyPairGeneratorSpi ()
```

<br />

<br />

## Public methods

### generateKeyPair

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public abstract KeyPair generateKeyPair ()
```

Generates a key pair. Unless an initialization method is called using a KeyPairGenerator interface, algorithm-specific defaults will be used. This will generate a new key pair every time it is called.

<br />

| Returns ||
|---|---|
| `https://developer.android.com/reference/java/security/KeyPair` | the newly generated `KeyPair` <br /> |

### initialize

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public void initialize (AlgorithmParameterSpec params, 
                SecureRandom random)
```

Initializes the key pair generator using the specified parameter set and user-provided source of randomness.

This concrete method has been added to this previously-defined abstract class. (For backwards compatibility, it cannot be abstract.) It may be overridden by a provider to initialize the key pair generator. Such an override is expected to throw an InvalidAlgorithmParameterException if a parameter is inappropriate for this key pair generator. If this method is not overridden, it always throws an UnsupportedOperationException.

<br />

| Parameters ||
|---|---|
| `params` | `AlgorithmParameterSpec`: the parameter set used to generate the keys. <br /> |
| `random` | `SecureRandom`: the source of randomness for this generator. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/security/InvalidAlgorithmParameterException` | if the given parameters are inappropriate for this key pair generator. |

### initialize

Added in [API level 1](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)

```
public abstract void initialize (int keysize, 
                SecureRandom random)
```

Initializes the key pair generator for a certain keysize, using the default parameter set.

<br />

| Parameters ||
|---|---|
| `keysize` | `int`: the keysize. This is an algorithm-specific metric, such as modulus length, specified in number of bits. <br /> |
| `random` | `SecureRandom`: the source of randomness for this generator. <br /> |

| Throws ||
|---|---|
| `https://developer.android.com/reference/java/security/InvalidParameterException` | if the `keysize` is not supported by this KeyPairGeneratorSpi object. |