EthereumIESEngine.HandshakeKDFFunction (Bouncy Castle Library 1.68 API Specification)

java.lang.Object
- org.bouncycastle.crypto.engines.EthereumIESEngine.HandshakeKDFFunction

All Implemented Interfaces:

DerivationFunction, DigestDerivationFunction

Enclosing class:

EthereumIESEngine
```
public static class EthereumIESEngine.HandshakeKDFFunction
extends java.lang.Object
implements DigestDerivationFunction
```
Basic KDF generator for derived keys and ivs as defined by IEEE P1363a/ISO 18033
This implementation is based on ISO 18033/P1363a.
This class has been adapted from the BaseKDFBytesGenerator implementation of Bouncy Castle. Only one change is present specifically for Ethereum.

Constructor Summary

Constructors
Constructor Description

HandshakeKDFFunction(int counterStart, Digest digest)
Construct a KDF Parameters generator.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`int`	`generateBytes(byte[] out, int outOff, int len)`	fill len bytes of the output buffer with bytes generated from the derivation function.
`Digest`	`getDigest()`	return the underlying digest.
`void`	`init(DerivationParameters param)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - HandshakeKDFFunction
```
public HandshakeKDFFunction(int counterStart,
                            Digest digest)
```
    Construct a KDF Parameters generator.
    
    Parameters:
    
    counterStart - value of counter.
    
    digest - the digest to be used as the source of derived keys.
- Method Detail
  - init
```
public void init(DerivationParameters param)
```
    Specified by:
    
    init in interface DerivationFunction
  - getDigest
```
public Digest getDigest()
```
    return the underlying digest.
    
    Specified by:
    
    getDigest in interface DigestDerivationFunction
  - generateBytes
```
public int generateBytes(byte[] out,
                         int outOff,
                         int len)
                  throws DataLengthException,
                         java.lang.IllegalArgumentException
```
    fill len bytes of the output buffer with bytes generated from the derivation function.
    
    Specified by:
    
    generateBytes in interface DerivationFunction
    
    Throws:
    
    java.lang.IllegalArgumentException - if the size of the request will cause an overflow.
    
    DataLengthException - if the out buffer is too small.