import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
protected Signer createSigner(AlgorithmIdentifier sigAlgId, AlgorithmIdentifier digAlgId)
        throws OperatorCreationException {
    if (!AlgorithmUtil.isRSASigAlgId(sigAlgId)) {
        throw new OperatorCreationException(
                "the given algorithm is not a valid RSA signature algirthm '"
                + sigAlgId.getAlgorithm().getId() + "'");
    }

    if (!PKCSObjectIdentifiers.id_RSASSA_PSS.equals(sigAlgId.getAlgorithm())) {
        Digest dig = digestProvider.get(digAlgId);
        return new RSADigestSigner(dig);
    }

    try {
        return SignerUtil.createPSSRSASigner(sigAlgId);
    } catch (XiSecurityException ex) {
        throw new OperatorCreationException(ex.getMessage(), ex);
    }
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
static Signer createSigner(int keyAlgorithm, int hashAlgorithm)
    throws PGPException
{
    switch(keyAlgorithm)
    {
    case PublicKeyAlgorithmTags.RSA_GENERAL:
    case PublicKeyAlgorithmTags.RSA_SIGN:
        return new RSADigestSigner(createDigest(hashAlgorithm));
    case PublicKeyAlgorithmTags.DSA:
        return new DSADigestSigner(new DSASigner(), createDigest(hashAlgorithm));
    case PublicKeyAlgorithmTags.ECDSA:
        return new DSADigestSigner(new ECDSASigner(), createDigest(hashAlgorithm));
    default:
        throw new PGPException("cannot recognise keyAlgorithm: " + keyAlgorithm);
    }
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
/**
 * Calculates the signature of a ticket and updates the given {@link Ticket} object directly.
 * 
 * @throws IllegalStateException
 *           If ticket cannot be signed.
 */
public void signTicket(Ticket ticket) throws IllegalStateException {
  byte[] serialized = TicketUtil.serialize(ticket);
  byte[] claimBytes = TicketUtil.deserialize(ByteBuffer.wrap(serialized)).getRight();

  RSAPrivateCrtKeyParameters signingKey = keyManager.getPrivateSigningKey();

  if (signingKey == null)
    throw new IllegalStateException("Cannot sign ticket because there is no private signing key available.");

  RSADigestSigner signer = new RSADigestSigner(new SHA256Digest());
  signer.init(true, signingKey);
  signer.update(claimBytes, 0, claimBytes.length);
  try {
    byte[] signature = signer.generateSignature();
    ticket.setSignature(signature);
  } catch (DataLengthException | CryptoException e) {
    throw new IllegalStateException("Cannot sign ticket", e);
  }
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
protected Signer createSigner(AlgorithmIdentifier sigAlgId)
    throws OperatorCreationException
{
    AlgorithmIdentifier digAlg = digestAlgorithmFinder.find(sigAlgId);
    Digest dig = digestProvider.get(digAlg);

    return new RSADigestSigner(dig);
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
protected Signer createSigner(AlgorithmIdentifier sigAlgId, AlgorithmIdentifier digAlgId)
    throws OperatorCreationException
{
    Digest dig = digestProvider.get(digAlgId);

    return new RSADigestSigner(dig);
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
@Override
protected Signer createSigner(AlgorithmIdentifier sigAlgId) throws OperatorCreationException {
    if (PKCSObjectIdentifiers.id_RSASSA_PSS.equals(sigAlgId.getAlgorithm())) {
        try {
            return SignerUtil.createPSSRSASigner(sigAlgId);
        } catch (XiSecurityException ex) {
            throw new OperatorCreationException(ex.getMessage(), ex);
        }
    } else {
        AlgorithmIdentifier digAlg = digestAlgorithmFinder.find(sigAlgId);
        return new RSADigestSigner(digestProvider.get(digAlg));
    }
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
public static void verifySignatureSHA256(APublicKey publicKey, byte[] payload, byte[] sig) throws Exception
{
	CipherParameters pub = getCipherParameters(publicKey);
	RSADigestSigner signer = new RSADigestSigner(new SHA256Digest());
	signer.init(false, pub);
	signer.update(payload, 0, payload.length);
	if(!signer.verifySignature(sig))
	{
		throw new Exception("failed signature verification");
	}
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
public static byte[] generateSignatureSHA256(APrivateKey privateKey, byte[] payload) throws Exception
{
	CipherParameters pub = getCipherParameters(privateKey);
	RSADigestSigner signer = new RSADigestSigner(new SHA256Digest());
	signer.init(true, pub);
	signer.update(payload, 0, payload.length);
	return signer.generateSignature();
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
/**
 * Checks if a {@link Ticket} has a valid signature.
 * 
 * @param deserializedTicket
 *          The result of {@link TicketUtil#deserialize(ByteBuffer)} of the serialized {@link Ticket}.
 * @return true if {@link Ticket} signature is valid.
 */
public boolean isValidTicketSignature(Pair<Ticket, byte[]> deserializedTicket) {
  for (RSAKeyParameters pubKey : keyManager.getPublicValidationKeys()) {
    RSADigestSigner signer = new RSADigestSigner(new SHA256Digest());
    signer.init(false, pubKey);
    signer.update(deserializedTicket.getRight(), 0, deserializedTicket.getRight().length);
    if (signer.verifySignature(deserializedTicket.getLeft().getSignature()))
      return true;
  }
  return false;
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
static Signer createSigner(int keyAlgorithm, int hashAlgorithm)
    throws PGPException
{
    switch(keyAlgorithm)
    {
    case PublicKeyAlgorithmTags.RSA_GENERAL:
    case PublicKeyAlgorithmTags.RSA_SIGN:
        return new RSADigestSigner(createDigest(hashAlgorithm));
    case PublicKeyAlgorithmTags.DSA:
        return new DSADigestSigner(new DSASigner(), createDigest(hashAlgorithm));
    default:
        throw new PGPException("cannot recognise keyAlgorithm");
    }
}
 

import org.bouncycastle.crypto.signers.RSADigestSigner; //导入依赖的package包/类
/**
 * Creates a new RSA signature class that uses the given digest algorithm
 * for message digest computation.
 *
 * @param d
 *            Message digest algorithm.
 */
public RSASignature(final DigestAlgorithm d) {
	super(ALGORITHM);
	digest = d;
	signer = new RSADigestSigner(d.getDigest());
}