VSFTPD require_ssl_reuse ssl ftp

While attempting to connect to a vsftpd server using SSL with a php script to upload a file I encountered this error message:

Warning:  ftp_put(): SSL connection failed; session reuse required: see require_ssl_reuse option in vsftpd.conf man page

The transfer does not complete successfully but an empty file is transferred.

http://vsftpd.beasts.org/vsftpd_conf.html

The vsftpd page says

require_ssl_reuse

If set to yes, all SSL data connections are required to exhibit SSL session reuse (which proves that they know the same master secret as the control channel). Although this is a secure default, it may break many FTP clients, so you may want to disable it. For a discussion of the consequences, see http://scarybeastsecurity.blogspot.com/2009/02/vsftpd-210-released.html (Added in v2.1.0).

Default: YES

This is an option to thwart the connection attack described here:

http://scarybeastsecurity.blogspot.ie/2008/02/your-ftp-ssl-solution-is-really-secure.html

The php client does not support the option “require_ssl_reuse” so if you disable require_ssl_reuse in the /etc/vsftpd/vsftpd.conf it will work, but you don’t have the extra protection this feature would give you.