crypto/tls: the whole http body is read, but an Unexpected EOF is return at the same time

[Jarvis-Zhou]

What version of Go are you using (go version)?

$ go version
go1.16.6 linux/amd64

Does this issue reproduce with the latest release?

yes

What operating system and processor architecture are you using (go env)?

amd64 ubuntu

What did you do?

I just send a http request and use ioutil.ReadAll to read body, all the body is read, but I got an unexpected error at the same time.

May my env is special, I use tcpdump and wareshark the trace the connection, I found that the last packet from server end with part of Alert meg 0x15 0x03 0x03, and later the server send a RST packet.

After reading golang code, I find out that after the whole body is read, we will check the alert packet. But as the alert packet is not full, will return the Unexpected EOF.

https://github.com/golang/go/blame/9e6ad46bccfa7a63e768236bcd1fd54dab38e4d1/src/crypto/tls/conn.go#L1305

What did you expect to see?

I think We should add a check here, this error show in resp.Body.Close or next read.

What did you see instead?

[Jarvis-Zhou]

CC @FiloSottile @bradfitz

[cagedmantis]

Could you provide an example of the code that produced the error, preferably as a Go playground link?

[Jarvis-Zhou]

https://play.golang.org/p/hCyV1oEl4YC , my code is just like this, very normal. But in my environment, I got an Unexpected EOF with the whole body. Then I add log print in tls/conn, I found that it will return Unexpected EOF when TLS Alert packet is not right.

[Jarvis-Zhou]

I also write my code using python or just using curl, it is ok. because they are not deal with the alert packet in body reading.

[Jarvis-Zhou]

[Jarvis-Zhou]

@cagedmantis

[cagedmantis]

@Jarvis-Zhou Thank you for the updated information.

[bradfitz]

Which web server is replying with this broken TLS interrupting its response?

[Jarvis-Zhou]

It is a http server in my local environment. And I am keeping on finding out the problem why it is interrupted.

[Jarvis-Zhou]

But other language does not return this error