org.bouncycastle.tls.TlsECDHanonKeyExchange Maven / Gradle / Ivy

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The Bouncy Castle Java APIs for the TLS, including a JSSE provider. The APIs are designed primarily to be used in conjunction with the BC FIPS provider. The APIs may also be used with other providers although if being used in a FIPS context it is the responsibility of the user to ensure that any other providers used are FIPS certified and used appropriately.

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package org.bouncycastle.tls;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.bouncycastle.tls.crypto.TlsAgreement;
import org.bouncycastle.tls.crypto.TlsECConfig;
import org.bouncycastle.tls.crypto.TlsSecret;

/**
 * (D)TLS ECDH_anon key exchange (see RFC 4492).
 */
public class TlsECDHanonKeyExchange
    extends AbstractTlsKeyExchange
{
    private static int checkKeyExchange(int keyExchange)
    {
        switch (keyExchange)
        {
        case KeyExchangeAlgorithm.ECDH_anon:
            return keyExchange;
        default:
            throw new IllegalArgumentException("unsupported key exchange algorithm");
        }
    }

    protected TlsECConfig ecConfig;

    protected TlsAgreement agreement;

    public TlsECDHanonKeyExchange(int keyExchange)
    {
        this(keyExchange, null);
    }

    public TlsECDHanonKeyExchange(int keyExchange, TlsECConfig ecConfig)
    {
        super(checkKeyExchange(keyExchange));

        this.ecConfig = ecConfig;
    }

    public void skipServerCredentials() throws IOException
    {
    }

    public void processServerCredentials(TlsCredentials serverCredentials) throws IOException
    {
        throw new TlsFatalAlert(AlertDescription.internal_error);
    }

    public void processServerCertificate(Certificate serverCertificate) throws IOException
    {
        throw new TlsFatalAlert(AlertDescription.unexpected_message);
    }

    public boolean requiresServerKeyExchange()
    {
        return true;
    }

    public byte[] generateServerKeyExchange() throws IOException
    {
        ByteArrayOutputStream buf = new ByteArrayOutputStream();

        TlsECCUtils.writeECConfig(ecConfig, buf);

        this.agreement = context.getCrypto().createECDomain(ecConfig).createECDH();

        generateEphemeral(buf);

        return buf.toByteArray();
    }

    public void processServerKeyExchange(InputStream input) throws IOException
    {
        this.ecConfig = TlsECCUtils.receiveECDHConfig(context, input);

        byte[] point = TlsUtils.readOpaque8(input, 1);

        this.agreement = context.getCrypto().createECDomain(ecConfig).createECDH();

        processEphemeral(point);
    }

    public short[] getClientCertificateTypes()
    {
        return null;
    }

    public void processClientCredentials(TlsCredentials clientCredentials) throws IOException
    {
        throw new TlsFatalAlert(AlertDescription.internal_error);
    }

    public void generateClientKeyExchange(OutputStream output) throws IOException
    {
        generateEphemeral(output);
    }

    public void processClientCertificate(Certificate clientCertificate) throws IOException
    {
        throw new TlsFatalAlert(AlertDescription.unexpected_message);
    }

    public void processClientKeyExchange(InputStream input) throws IOException
    {
        byte[] point = TlsUtils.readOpaque8(input, 1);

        processEphemeral(point);
    }

    public TlsSecret generatePreMasterSecret() throws IOException
    {
        return agreement.calculateSecret();
    }

    protected void generateEphemeral(OutputStream output) throws IOException
    {
        byte[] point = agreement.generateEphemeral();

        TlsUtils.writeOpaque8(point, output);
    }

    protected void processEphemeral(byte[] point) throws IOException
    {
        TlsECCUtils.checkPointEncoding(ecConfig.getNamedGroup(), point);

        this.agreement.receivePeerValue(point);
    }
}