New submission from Ye Wang: According to RFC4217 (Securing FTP with TLS, aka the FTPS spec),
http://tools.ietf.org/html/rfc4217.html#section-10.2 " It is reasonable for the server to insist that the data connection uses a TLS cached session. This might be a cache of a previous data connection or of a cleared control connection. If this is the reason for the refusal to allow the data transfer, then the '522' reply should indicate this. Note: This has an important impact on client design, but allows servers to minimize the cycles used during TLS negotiation by refusing to perform a full negotiation with a previously authenticated client." It appears that vsftpd server implemented exactly that by enforcing the "SSL session reuse between the control and data connection". http://scarybeastsecurity.blogspot.com/2009/02/vsftpd-210-released.html Looking at the source of Python core library ftplib.py, there isn't any regard to the idea of SSL session reuse between data connection vs. control connection (correct me if I am wrong here. I've tried FTP_TLS.transfercmd(cmd[, rest])ΒΆ, didn't work). This issue is well documented on other FTP clients that supports FTPS, I.E. WinSCP: http://winscp.net/tracker/show_bug.cgi?id=668 See test log file attached. A vsftpd server with "require_ssl_reuse" set to true in vsftpd.conf would do the trick and can be reproduced. ---------- components: Library (Lib) files: ftplib-FTPS-bug.txt messages: 202193 nosy: Ye.Wang priority: normal severity: normal status: open title: Error when connecting to FTPS servers not supporting SSL session resuming type: behavior versions: Python 2.7, Python 3.1, Python 3.2, Python 3.3, Python 3.4, Python 3.5 Added file: http://bugs.python.org/file32505/ftplib-FTPS-bug.txt _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue19500> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
