Package org.bouncycastle.crypto.agreement.kdf

## Class ConcatenationKDFGenerator

- java.lang.Object
- - org.bouncycastle.crypto.agreement.kdf.ConcatenationKDFGenerator

- All Implemented Interfaces:
    `DerivationFunction`

      public class ConcatenationKDFGenerator
      extends java.lang.Object
      implements DerivationFunction

  Generator for Concatenation Key Derivation Function defined in NIST SP 800-56A, Sect 5.8.1

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `ConcatenationKDFGenerator​(Digest digest)` |

  - ### 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

    - #### ConcatenationKDFGenerator

          public ConcatenationKDFGenerator​(Digest digest)

      Parameters:
        `digest` - the digest to be used as the source of generated bytes

  - ### Method Detail

    - #### init

          public void init​(DerivationParameters param)

      Specified by:
        `init` in interface `DerivationFunction`

    - #### getDigest

          public Digest getDigest()

      return the underlying digest.

    - #### 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:
        `DataLengthException` - if the out buffer is too small.
        `java.lang.IllegalArgumentException`