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

Go to download
Show more of this group Show more artifacts with this name
Show all versions of bctls-fips Show documentation
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.
There is a newer version: 2.0.19
Show newest version
package org.bouncycastle.tls;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;

import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.io.TeeInputStream;

public class ClientHello
{
    private final ProtocolVersion version;
    private final byte[] random;
    private final byte[] sessionID;
    private final byte[] cookie;
    private final int[] cipherSuites;
    private final Hashtable extensions;
    private final int bindersSize;

    public ClientHello(ProtocolVersion version, byte[] random, byte[] sessionID, byte[] cookie,
        int[] cipherSuites, Hashtable extensions, int bindersSize)
    {
        this.version = version;
        this.random = random;
        this.sessionID = sessionID;
        this.cookie = cookie;
        this.cipherSuites = cipherSuites;
        this.extensions = extensions;
        this.bindersSize = bindersSize;
    }

    public int getBindersSize()
    {
        return bindersSize;
    }

    public int[] getCipherSuites()
    {
        return cipherSuites;
    }

    /**
     * @deprecated Use {@link #getVersion()} instead.
     */
    public ProtocolVersion getClientVersion()
    {
        return version;
    }
    
    public byte[] getCookie()
    {
        return cookie;
    }

    public Hashtable getExtensions()
    {
        return extensions;
    }

    public byte[] getRandom()
    {
        return random;
    }

    public byte[] getSessionID()
    {
        return sessionID;
    }

    public ProtocolVersion getVersion()
    {
        return version;
    }

    /**
     * Encode this {@link ClientHello} to an {@link OutputStream}.
     * 
     * @param output
     *            the {@link OutputStream} to encode to.
     * @throws IOException
     */
    public void encode(TlsContext context, OutputStream output) throws IOException
    {
        if (bindersSize < 0)
        {
            throw new TlsFatalAlert(AlertDescription.internal_error);
        }

        TlsUtils.writeVersion(version, output);

        output.write(random);

        TlsUtils.writeOpaque8(sessionID, output);

        if (null != cookie)
        {
            TlsUtils.writeOpaque8(cookie, output);
        }

        TlsUtils.writeUint16ArrayWithUint16Length(cipherSuites, output);

        TlsUtils.writeUint8ArrayWithUint8Length(new short[]{ CompressionMethod._null }, output);

        TlsProtocol.writeExtensions(output, extensions, bindersSize);
    }

    /**
     * Parse a {@link ClientHello} from a {@link ByteArrayInputStream}.
     *
     * @param messageInput
     *            the {@link ByteArrayInputStream} to parse from.
     * @param dtlsOutput
     *            for DTLS this should be non-null; the input is copied to this
     *            {@link OutputStream}, minus the cookie field.
     * @return a {@link ClientHello} object.
     * @throws TlsFatalAlert
     */
    public static ClientHello parse(ByteArrayInputStream messageInput, OutputStream dtlsOutput)
        throws TlsFatalAlert
    {
        try
        {
            return implParse(messageInput, dtlsOutput);
        }
        catch (TlsFatalAlert e)
        {
            throw e;
        }
        catch (IOException e)
        {
            throw new TlsFatalAlert(AlertDescription.decode_error, e);
        }
    }

    private static ClientHello implParse(ByteArrayInputStream messageInput, OutputStream dtlsOutput)
        throws IOException
    {
        InputStream input = messageInput;
        if (null != dtlsOutput)
        {
            input = new TeeInputStream(input, dtlsOutput);
        }

        ProtocolVersion clientVersion = TlsUtils.readVersion(input);

        byte[] random = TlsUtils.readFully(32, input);

        byte[] sessionID = TlsUtils.readOpaque8(input, 0, 32);

        byte[] cookie = null;
        if (null != dtlsOutput)
        {
            /*
             * RFC 6347 This specification increases the cookie size limit to 255 bytes for greater
             * future flexibility. The limit remains 32 for previous versions of DTLS.
             */
            int maxCookieLength = ProtocolVersion.DTLSv12.isEqualOrEarlierVersionOf(clientVersion) ? 255 : 32;

            cookie = TlsUtils.readOpaque8(messageInput, 0, maxCookieLength);
        }

        int cipher_suites_length = TlsUtils.readUint16(input);
        if (cipher_suites_length < 2 || (cipher_suites_length & 1) != 0
            || messageInput.available() < cipher_suites_length)
        {
            throw new TlsFatalAlert(AlertDescription.decode_error);
        }

        /*
         * NOTE: "If the session_id field is not empty (implying a session resumption request) this
         * vector must include at least the cipher_suite from that session."
         */
        int[] cipherSuites = TlsUtils.readUint16Array(cipher_suites_length / 2, input);

        short[] compressionMethods = TlsUtils.readUint8ArrayWithUint8Length(input, 1);
        if (!Arrays.contains(compressionMethods, CompressionMethod._null))
        {
            throw new TlsFatalAlert(AlertDescription.handshake_failure);
        }

        /*
         * NOTE: Can't use TlsProtocol.readExtensions directly because TeeInputStream a) won't have
         * 'available()' method in the FIPS provider, b) isn't a ByteArrayInputStream.
         */
        Hashtable extensions = null;
        if (messageInput.available() > 0)
        {
            byte[] extBytes = TlsUtils.readOpaque16(input);

            TlsProtocol.assertEmpty(messageInput);

            extensions = TlsProtocol.readExtensionsDataClientHello(extBytes);
        }

        return new ClientHello(clientVersion, random, sessionID, cookie, cipherSuites, extensions, -1);
    }
}