Example usage for org.bouncycastle.crypto.signers RSADigestSigner generateSignature

Introduction

In this page you can find the example usage for org.bouncycastle.crypto.signers RSADigestSigner generateSignature.

Prototype

public byte[] generateSignature() throws CryptoException, DataLengthException 

Source Link

Document

Generate a signature for the message we've been loaded with using the key we were initialised with.

Usage

From source file:org.cryptacular.util.KeyPairUtil.java

License:Open Source License

/**
 * Determines whether the given RSA public and private keys form a proper key
 * pair by computing and verifying a digital signature with the keys.
 *
 * @param  pubKey  RSA public key./*from  w  w w  .  jav  a2s  .c om*/
 * @param  privKey  RSA private key.
 *
 * @return  True if the keys form a functioning keypair, false otherwise.
 *          Errors during signature verification are treated as false.
 */
public static boolean isKeyPair(final RSAPublicKey pubKey, final RSAPrivateKey privKey) {
    final RSADigestSigner signer = new RSADigestSigner(new SHA256Digest());
    signer.init(true, new RSAKeyParameters(true, privKey.getModulus(), privKey.getPrivateExponent()));
    signer.update(SIGN_BYTES, 0, SIGN_BYTES.length);
    try {
        final byte[] sig = signer.generateSignature();
        signer.init(false, new RSAKeyParameters(false, pubKey.getModulus(), pubKey.getPublicExponent()));
        signer.update(SIGN_BYTES, 0, SIGN_BYTES.length);
        return signer.verifySignature(sig);
    } catch (CryptoException e) {
        return false;
    }
}

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From source file:org.diqube.ticket.TicketSignatureService.java

License:Open Source License

/**
 * Calculates the signature of a ticket and updates the given {@link Ticket} object directly.
 * /*  w w  w.  ja va 2  s. com*/
 * @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);
    }
}

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