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A solution to Square's "Square Root" Java puzzler (http://corner.squareup.com/2013/03/puzzle-square-root.html)
import square.SquareRoot;
import java.math.BigInteger;
import java.security.Provider;
import java.security.SecureRandomSpi;
import java.security.Security;
/**
* A Not very secure random provider implementation.
* Made for Square's "Square Root" Java puzzler (2013/03/19).
* @author Erik Tjernlund (erik@tjernlund.net)
*/
public class EriksNotSecureRandomSpi extends SecureRandomSpi {
@Override
protected void engineSetSeed(byte[] seed) {
}
@Override
protected void engineNextBytes(byte[] bytes) {
bytes[bytes.length - 1] = 1;
}
@Override
protected byte[] engineGenerateSeed(int numBytes) {
return new byte[0];
}
}
/**
* Security provider that registers an insane secure random algorithm implementation.
* Made for Square's "Square Root" Java puzzler (2013/03/19).
* @author Erik Tjernlund (erik@tjernlund.net)
*/
final class EriksSecurityProvider extends Provider {
public EriksSecurityProvider(String name, double version, String info) {
super(name, version, info);
put("SecureRandom.SHA1PRNG", "EriksNotSecureRandomSpi");
}
/**
* Run to solve Square's "Square Root" Java puzzler (2013/03/19).
*/
public static void main(String[] args) {
Provider provider = new EriksSecurityProvider("EriksSecurityProvider", 1.0, "Erik's not really very secure security provider");
Security.insertProviderAt(provider, 1);
SquareRoot.answer(new BigInteger("1"));
}
}
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