// 
// Decompiled by Procyon v0.6.0
// 

package org.bouncycastle.crypto.generators;

import org.bouncycastle.util.BigIntegers;
import org.bouncycastle.crypto.params.RSAPrivateCrtKeyParameters;
import org.bouncycastle.crypto.CryptoServicesRegistrar;
import org.bouncycastle.crypto.params.ParametersWithRandom;
import org.bouncycastle.crypto.CipherParameters;
import java.security.SecureRandom;
import org.bouncycastle.crypto.params.RSAKeyParameters;
import java.math.BigInteger;

public class RSABlindingFactorGenerator
{
    private static BigInteger TWO;
    private RSAKeyParameters key;
    private SecureRandom random;
    
    public void init(final CipherParameters cipherParameters) {
        if (cipherParameters instanceof ParametersWithRandom) {
            final ParametersWithRandom parametersWithRandom = (ParametersWithRandom)cipherParameters;
            this.key = (RSAKeyParameters)parametersWithRandom.getParameters();
            this.random = parametersWithRandom.getRandom();
        }
        else {
            this.key = (RSAKeyParameters)cipherParameters;
            this.random = CryptoServicesRegistrar.getSecureRandom();
        }
        if (this.key instanceof RSAPrivateCrtKeyParameters) {
            throw new IllegalArgumentException("generator requires RSA public key");
        }
    }
    
    public BigInteger generateBlindingFactor() {
        if (this.key == null) {
            throw new IllegalStateException("generator not initialised");
        }
        final BigInteger modulus = this.key.getModulus();
        final int n = modulus.bitLength() - 1;
        BigInteger randomBigInteger;
        do {
            randomBigInteger = BigIntegers.createRandomBigInteger(n, this.random);
        } while (randomBigInteger.compareTo(RSABlindingFactorGenerator.TWO) < 0 || !BigIntegers.modOddIsCoprime(modulus, randomBigInteger));
        return randomBigInteger;
    }
    
    static {
        RSABlindingFactorGenerator.TWO = BigInteger.valueOf(2L);
    }
}