Socks5PrivateAuthRequestDecoder Class — netty Architecture

Source Code

codec-socks/src/main/java/io/netty/handler/codec/socksx/v5/Socks5PrivateAuthRequestDecoder.java lines 32–94

public final class Socks5PrivateAuthRequestDecoder extends ByteToMessageDecoder {

    private boolean decoded;

    @Override
    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception {
        try {
            if (decoded) {
                int readableBytes = in.readableBytes();
                if (readableBytes > 0) {
                    out.add(in.readRetainedSlice(readableBytes));
                }
                return;
            }

            // Check if we have enough data to decode the message
            if (in.readableBytes() < 2) {
                return;
            }

            final int startOffset = in.readerIndex();
            final byte version = in.getByte(startOffset);
            if (version != 1) {
                throw new DecoderException("unsupported subnegotiation version: " + version + " (expected: 1)");
            }

            final int tokenLength = in.getUnsignedByte(startOffset + 1);

            // Check if the full message is available
            if (in.readableBytes() < 2 + tokenLength) {
                return;
            }

            // Read the version and token length
            in.skipBytes(2);

            // Read the token
            byte[] token = new byte[tokenLength];
            in.readBytes(token);

            // Add the decoded token to the output list
            out.add(new DefaultSocks5PrivateAuthRequest(token));

            // Mark as decoded to handle remaining bytes in future calls
            decoded = true;
        } catch (Exception e) {
            fail(out, e);
        }
    }

    private void fail(List<Object> out, Exception cause) {
        if (!(cause instanceof DecoderException)) {
            cause = new DecoderException(cause);
        }

        decoded = true;

        Socks5Message m = new
            DefaultSocks5PrivateAuthRequest(EmptyArrays.EMPTY_BYTES);
        m.setDecoderResult(DecoderResult.failure(cause));
        out.add(m);
    }
}