Module java.base
Package java.security.interfaces

# Interface XECPrivateKey

All Superinterfaces:
  `Destroyable`, `Key`, `PrivateKey`, `Serializable`, `XECKey`

public interface XECPrivateKey extends XECKey, PrivateKey
An interface for an elliptic curve private key as defined by RFC 7748. These keys are distinct from the keys represented by `ECPrivateKey`, and they are intended for use with algorithms based on RFC 7748 such as the XDH `KeyAgreement` algorithm. An XEC private key is an encoded scalar value as described in RFC 7748. The decoding procedure defined in this RFC includes an operation that forces certain bits of the key to either 1 or 0. This operation is known as "pruning" or "clamping" the private key. Arrays returned by this interface are unpruned, and implementations will need to prune the array before using it in any numerical operations.

Since:
  11

## Field Summary

### Fields declared in interface java.security.PrivateKey

`serialVersionUID`

## Method Summary

Modifier and Type
Method
Description
`Optional<byte[]>`
`getScalar()`
Get the scalar value encoded as an unpruned byte array.

### Methods declared in interface javax.security.auth.Destroyable

`destroy, isDestroyed`

### Methods declared in interface java.security.Key

`getAlgorithm, getEncoded, getFormat`

### Methods declared in interface java.security.interfaces.XECKey

`getParams`

## Method Details

### getScalar

Optional<byte[]> getScalar()
Get the scalar value encoded as an unpruned byte array. A new copy of the array is returned each time this method is called.

Returns:
  the unpruned encoded scalar value, or an empty Optional if the scalar cannot be extracted (e.g. if the provider is a hardware token and the private key is not allowed to leave the crypto boundary).