/**
* Generates a user-specified number of random bytes.
*
* @param bytes The array to fill with random bytes.
*/
public void engineNextBytes(byte[] bytes) {
int index = 0;
int todo;
byte[] output = this.remainder;
// First use remainder from last time
int rC = this.remCount;
if (rC > 0) {
todo = (bytes.length - index) < (4 - rC) ? (bytes.length - index) : (4 - rC);
for (int i = 0; i < todo; i++, rC++) bytes[i] = output[rC];
this.remCount += todo;
index += todo;
}
// If we need more bytes, get them
while (index < bytes.length) {
output = ISAACEngine.toByteArray(this.isaac.nextInt());
todo = (bytes.length - index) > 4 ? 4 : (bytes.length - index);
for (int i = 0; i < todo; i++, index++) bytes[index] = output[i];
this.remCount += todo;
}
// Store remainder for next time
this.remainder = output;
this.remCount %= 4;
}
/**
* Reseeds this random object. The given seed supplements, rather than replaces, the existing
* seed.
*
* @param seed The seed.
*/
public void engineSetSeed(byte[] seed) {
this.isaac.supplementSeed(ISAACEngine.packToIntArray(seed));
}
/**
* Creates a new instance and seeds it with random data obtained from <code>
* java.security.SecureRandom</code>'s <code>getSeed()</code> method.
*/
public ISAACEngine() {
byte[] temp = new byte[1024]; // SecureRandom.getSeed (1024);
new SecureRandom().nextBytes(temp);
this.isaac = new ISAACAlgorithm(ISAACEngine.packToIntArray(temp));
}
