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package wonka.security;
import java.security.SecureRandomSpi;
import java.util.Random;
/**
** This class is not very Secure since we use a the java.util.Random to get the next values.
** But at least it is a start and it will make sure that the SecureRandom class will work
** (but not so secure as wanted ...).
*/
public final class SecureRandomImpl extends SecureRandomSpi {
private Random random;
public SecureRandomImpl(){
long seed = System.currentTimeMillis();
int sign = (short)seed;
seed = seed ^ ((long)sign)<<32;
Runtime rt = Runtime.getRuntime();
seed ^= rt.freeMemory()<<47;
seed ^= (rt.totalMemory())<<33;
seed ^= (((long)hashCode()) << 32 ) | rt.hashCode();
random = new Random(seed);
}
protected byte[] engineGenerateSeed(int numOfBytes) {
byte[] seed = new byte[numOfBytes];
engineNextBytes(seed);
return seed;
}
protected void engineNextBytes(byte[] bytes) {
random.nextBytes(bytes);
int size = bytes.length;
for (int i = 0 ; i < size ; i++){
int pos = random.nextInt(size);
byte b = bytes[i];
bytes[i] = bytes[pos];
bytes[pos] = b;
}
}
protected void engineSetSeed(byte[] seedBytes) {
int stop = seedBytes.length;
if(stop > 8){
stop = 8;
}
long seed = 0;
for(int i = 0 ; i < stop ; i++){
seed = seed<<8 | (0xff & (char)seedBytes[i]);
}
random.setSeed(seed);
}
}