private void checkMask(int count, DerivationFunction kdf, byte[] seed, byte[] result) {
byte[] data = new byte[result.length];
kdf.init(new MGFParameters(seed));
kdf.generateBytes(data, 0, data.length);
if (!areEqual(result, data)) {
fail("MGF1 failed generator test " + count);
}
}
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 ASN1ObjectIdentifier(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);
}