Connection closed unexpectedly using AEAD ciphers

[RyanBernX]

Hi,

I am using ss-qt5 on Linux but it seems not working properly with AEAD ciphers (such as aes-256-gcm). Connections are closed soon after they are established.

Steps to reproduce

• Server : CentOS 7, shadowsocks-libev-3.2.0
• Client: CentOS 7 and Fedora 28, shadowsocks-qt5-3.0.1. I am using the AppImage directly from the release page.
• Both sides use aes-256-gcm.
• After connected to the server, download any file using socks5 proxy

  
  [user@localhost ~]$ curl --socks5-hostname 127.0.0.1:1080 -v http://ftp.tsukuba.wide.ad.jp/software/gcc/releases/gcc-7.3.0/gcc-7.3.0.tar.gz -o gcc.tar.gz

• Trying 127.0.0.1...
• TCP_NODELAY set % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* SOCKS5 communication to ftp.tsukuba.wide.ad.jp:80
• SOCKS5 request granted.
• Connected to 127.0.0.1 (127.0.0.1) port 1080 (#0)

  GET /software/gcc/releases/gcc-7.3.0/gcc-7.3.0.tar.gz HTTP/1.1 Host: ftp.tsukuba.wide.ad.jp User-Agent: curl/7.58.0 Accept: /

  0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0< HTTP/1.1 200 OK < Date: Fri, 29 Jun 2018 09:01:22 GMT < Server: Apache < Last-Modified: Thu, 25 Jan 2018 08:54:27 GMT < ETag: "6b010bd-56395ed5b16c0" < Accept-Ranges: bytes < Content-Length: 112201917 < Content-Type: application/x-gzip < Content-Encoding: x-gzip < { [12774 bytes data] 5 107M 5 5525k 0 0 1062k 0 0:01:43 0:00:05 0:01:38 1105k* transfer closed with 106224679 bytes remaining to read 5 107M 5 5837k 0 0 1089k 0 0:01:40 0:00:05 0:01:35 1441k

• Closing connection 0 curl: (18) transfer closed with 106224679 bytes remaining to read

• Same issue occurs when using browsers (e.g. firefox) to download files through the proxy.

However, it seems that I can still access the websites using proxy, but cannot download files.

Debugging information

After checking the output of ss-qt5 I find many error messages like:

AEAD data chunk is incomplete (too small for payload)
AEAD data chunk is incomplete (too small for length)
Remote: Integrity failure: GCM tag check failed

On the server side, the ss-server throws this error:

2018-06-29 08:28:23 ERROR: server recv: Connection reset by peer

Other Notes

• Same issue occurs when using aes-192-gcm, aes-128-gcm, chacha20-ietf-poly1305. But other ciphers such as aes-256-cfb and aes-256-ctr work fine using ss-qt5.
• AEAD ciphers work fine using ss-local from shadowsocks-libev on my PC.

Any idea on this issue?

[librehat]

I'm not sure why this would happen. It was firstly reported here https://github.com/shadowsocks/libQtShadowsocks/issues/165

[RyanBernX]

Thanks. Look forward to the updates.