import org.bouncycastle.bcpg.RSAPublicBCPGKey; //导入依赖的package包/类
private void init(KeyFingerPrintCalculator fingerPrintCalculator)
    throws PGPException
{
    BCPGKey                key = publicPk.getKey();

    this.fingerprint = fingerPrintCalculator.calculateFingerprint(publicPk);

    if (publicPk.getVersion() <= 3)
    {
        RSAPublicBCPGKey    rK = (RSAPublicBCPGKey)key;
        
        this.keyID = rK.getModulus().longValue();
        this.keyStrength = rK.getModulus().bitLength();
    }
    else
    {
        this.keyID = ((long)(fingerprint[fingerprint.length - 8] & 0xff) << 56)
                        | ((long)(fingerprint[fingerprint.length - 7] & 0xff) << 48)
                        | ((long)(fingerprint[fingerprint.length - 6] & 0xff) << 40)
                        | ((long)(fingerprint[fingerprint.length - 5] & 0xff) << 32)
                        | ((long)(fingerprint[fingerprint.length - 4] & 0xff) << 24)
                        | ((long)(fingerprint[fingerprint.length - 3] & 0xff) << 16)
                        | ((long)(fingerprint[fingerprint.length - 2] & 0xff) << 8)
                        | ((fingerprint[fingerprint.length - 1] & 0xff));
        
        if (key instanceof RSAPublicBCPGKey)
        {
            this.keyStrength = ((RSAPublicBCPGKey)key).getModulus().bitLength();
        }
        else if (key instanceof DSAPublicBCPGKey)
        {
            this.keyStrength = ((DSAPublicBCPGKey)key).getP().bitLength();
        }
        else if (key instanceof ElGamalPublicBCPGKey)
        {
            this.keyStrength = ((ElGamalPublicBCPGKey)key).getP().bitLength();
        }
    }
}
 

import org.bouncycastle.bcpg.RSAPublicBCPGKey; //导入依赖的package包/类
private final static void checkWeakKey(PGPPublicKey pk)
    throws PGPException
{
    BCPGKey k = pk.getPublicKeyPacket().getKey();
    if (k instanceof RSAPublicBCPGKey) {
        checkWeakRSA((RSAPublicBCPGKey) k);
    }
    else if (k instanceof DSAPublicBCPGKey) {
        checkDSA((DSAPublicBCPGKey) k);
    }
    // tbd
}
 

import org.bouncycastle.bcpg.RSAPublicBCPGKey; //导入依赖的package包/类
private final static void checkWeakRSA(RSAPublicBCPGKey rsak)
    throws PGPException
{
    BigInteger n = rsak.getModulus();
    BigInteger e = rsak.getPublicExponent();

    // n and e should be odd.
    if (!n.testBit(0) || !e.testBit(0)) {
        throw new PGPException("modulus and exponent must not be even.");
    }

    // e should be > 2
    if (e.compareTo(TWO) <= 0) {
        throw new PGPException("exponent must be >= 3");
    }

    // modulus should fail primality test
    if (n.isProbablePrime(80)) {
        throw new PGPException
            ("modulus doesn't seem to be a composite number.");
    }

    // modulus should have no small factors
    BigInteger factor = n.gcd(SMALL_FACTORS);
    if (!factor.equals(BigInteger.ONE)) {
        throw new PGPException("modulus has a small factor ("+factor+")");
    }
}