fail to check capability in handshake packet

[zhangyangyu]

When connecting to a MySQL server, it might throw such errors:

Exception in thread "main" io.r2dbc.spi.R2dbcPermissionDeniedException: [HY000] Server version '0.0.0' does not support SSL but mode 'VERIFY_IDENTITY' requires SSL
	at dev.miku.r2dbc.mysql.InitHandler.clientCapabilities(QueryFlow.java:665)
	at dev.miku.r2dbc.mysql.InitHandler.initHandshake(QueryFlow.java:704)
	at dev.miku.r2dbc.mysql.InitHandler.accept(QueryFlow.java:600)
	at dev.miku.r2dbc.mysql.InitHandler.accept(QueryFlow.java:545)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:112)
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:854)
	at reactor.core.publisher.MonoFlatMapMany$FlatMapManyInner.onNext(MonoFlatMapMany.java:250)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onNext(FluxPeek.java:200)
	at reactor.core.publisher.FluxHandle$HandleSubscriber.onNext(FluxHandle.java:128)
	at reactor.core.publisher.FluxPeekFuseable$PeekConditionalSubscriber.onNext(FluxPeekFuseable.java:854)
	at reactor.core.publisher.EmitterProcessor.drain(EmitterProcessor.java:537)
	at reactor.core.publisher.EmitterProcessor.tryEmitNext(EmitterProcessor.java:343)
	at reactor.core.publisher.InternalManySink.emitNext(InternalManySink.java:27)
	at reactor.core.publisher.EmitterProcessor.onNext(EmitterProcessor.java:309)
	at dev.miku.r2dbc.mysql.client.ReactorNettyClient$ResponseSink.next(ReactorNettyClient.java:340)
	at dev.miku.r2dbc.mysql.client.ReactorNettyClient.lambda$new$0(ReactorNettyClient.java:103)
	at reactor.core.publisher.FluxPeek$PeekSubscriber.onNext(FluxPeek.java:185)
	at reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:219)
	at reactor.netty.channel.FluxReceive.onInboundNext(FluxReceive.java:353)
	at reactor.netty.channel.ChannelOperations.onInboundNext(ChannelOperations.java:353)
	at reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:96)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at dev.miku.r2dbc.mysql.client.MessageDuplexCodec.handleDecoded(MessageDuplexCodec.java:187)
	at dev.miku.r2dbc.mysql.client.MessageDuplexCodec.channelRead(MessageDuplexCodec.java:95)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:324)
	at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:296)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
	at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:714)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:650)
	at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:576)
	at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
	at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	at java.base/java.lang.Thread.run(Thread.java:829)
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99)
		at reactor.core.publisher.Flux.blockLast(Flux.java:2746)
		at org.example.r2dbc.main(r2dbc.java:18)

But the server does support SSL and the capability flags are set correctly in handshake packet. The reason is that when reading salt in handshake packet it uses readcstring.

r2dbc-mysql/src/main/java/dev/miku/r2dbc/mysql/message/server/HandshakeV10Request.java

Line 145 in bdba9ee

salt.addComponent(true, readCStringRetainedSlice(buf));

So if there is any zero byte in salt part, it breaks. Another thing is the error message reports version 0.0.0, this is not right since in the code the error is thrown before context initialized. https://github.com/mirromutth/r2dbc-mysql/blob/5bdac223822e05b511c74137498c2c90e88d18e9/src/main/java/dev/miku/r2dbc/mysql/QueryFlow.java#L893~L896

Seems this commit already solves this problem a610517#diff-56968f905d43698e634f706f892dfc1898cf586f90db85e0865c88394db4f600, but unfortunately it's not released yet.