Because TLS versions older than TLS 1.2 are declared as "deprecated" by the IETF, FTP now supports only version 1.2 of the TLS protocol. Therefore the option -tlsProtocol is currently superfluous, but becomes useful again, when FTP starts to support TLS 1.3. The usage of the previous option values SSLv3, TLSv1 or TLSv1.1 leads to a warning message and ignoring the option value.
As the OpenSSL interface behind this option is declared as "deprecated", in future the option will be replaced by the options -tlsMinProtcolVersion and -tlsMaxProtocolVersion.
-tlsProtocol |
[+ | -] { TLSv1.2 | ALL } ... |
+
The protocol specified after this sign is permissible.
-
The protocol specified after this sign is not permissible.
If neither “+” nor “-” is specified, this has the same effect as specifying “+”.
TLSv1.2
TLS protocol version 1.2.
ALL
All supported protocols are to be enabled; curently this is only TLS 1.2.
ALL is the default.
Example
The specifications -tlsProtocol ALL and -tlsProtocol TLSv1.2 have the same effect as long as no support of the TLS version 1.3 is added to FTP.