How to use

generateBytes

method

in

org.spongycastle.crypto.DerivationFunction

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

private byte[] generateKdfBytes(
  KDFParameters kParam,
  int length)
{
  byte[]  buf = new byte[length];
  kdf.init(kParam);
  kdf.generateBytes(buf, 0, buf.length);
  return buf;
}

  protected KeyParameter generateKey(BigInteger n, BigInteger r, int keyLen)
  {
    byte[] R = BigIntegers.asUnsignedByteArray((n.bitLength() + 7) / 8, r);

    // Initialise the KDF
    kdf.init(new KDFParameters(R, null));

    // Generate the secret key
    byte[] K = new byte[keyLen];
    kdf.generateBytes(K, 0, K.length);

    return new KeyParameter(K);
  }
}

protected SecretKey engineGenerateSecret(
  String algorithm)
  throws NoSuchAlgorithmException
{
  byte[] secret = bigIntToBytes(result);
  if (kdf != null)
  {
    if (!algorithms.containsKey(algorithm))
    {
      throw new NoSuchAlgorithmException("unknown algorithm encountered: " + algorithm);
    }
    
    int    keySize = ((Integer)algorithms.get(algorithm)).intValue();
    DHKDFParameters params = new DHKDFParameters(new DERObjectIdentifier(algorithm), keySize, secret);
    byte[] keyBytes = new byte[keySize / 8];
    kdf.init(params);
    kdf.generateBytes(keyBytes, 0, keyBytes.length);
    secret = keyBytes;
  }
  else
  {
    // TODO Should we be ensuring the key is the right length?
  }
  return new SecretKeySpec(secret, algorithm);
}

kdf.generateBytes(keyBytes, 0, keyBytes.length);

  protected KeyParameter deriveKey(int keyLen, byte[] C, byte[] PEH)
  {
    byte[] kdfInput = PEH;
    if (!SingleHashMode)
    {
      kdfInput = Arrays.concatenate(C, PEH);
      Arrays.fill(PEH, (byte)0);
    }

    try
    {
      // Initialise the KDF
      kdf.init(new KDFParameters(kdfInput, null));
  
      // Generate the secret key
      byte[] K = new byte[keyLen];
      kdf.generateBytes(K, 0, K.length);

      // Return the ciphertext
      return new KeyParameter(K);
    }
    finally
    {
      Arrays.fill(kdfInput, (byte)0);
    }
  }
}

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

public int generateBytes(byte[] out, int outOff, int len)
  throws DataLengthException, IllegalArgumentException
{
  // TODO Create an ASN.1 class for this (RFC3278)
  // ECC-CMS-SharedInfo
  ASN1EncodableVector v = new ASN1EncodableVector();
  v.add(new AlgorithmIdentifier(algorithm, new DERNull()));
  v.add(new DERTaggedObject(true, 2, new DEROctetString(integerToBytes(keySize))));
  try
  {
    kdf.init(new KDFParameters(z, new DERSequence(v).getEncoded(ASN1Encoding.DER)));
  }
  catch (IOException e)
  {
    throw new IllegalArgumentException("unable to initialise kdf: " + e.getMessage());
  }
  return kdf.generateBytes(out, outOff, len);
}

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);

K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
K = new byte[K1.length + K2.length];
kdf.generateBytes(K, 0, K.length);
System.arraycopy(K, 0, K1, 0, K1.length);
System.arraycopy(K, K1.length, K2, 0, K2.length);