The only reason I mentioned it was, as you may remember, my mission is to connect to a Linux FTP server using AUTH TLS. Everything is fine except if I select "Passive" mode and PROT=Private, I cannot login. I get SSL handshake errors. They suggested that I should use BLOCK mode in this instance. I'm not so sure that this is the solution and may just tell them there are plenty of other combinations that work.

Incidentally using the ICS SSL FTP Client demo with the Server demo does not have any issues with any combination of Active/Passive and Private/Clear.


On 12/02/2018 11:18, Angus Robertson - Magenta Systems Ltd wrote:
I see that the component supports MODE S and MODE Z. Is there any
way it can, or will in the future, support MODE B (Block)?
Block mode goes back to the RFC959 written over 40 years ago, before
the internet really existed and FTP was used by mainframe computers.

I've never really come across it until you mentioned it, but a little
Googling suggests IIS FTP7 does actually support it, and it may be
beneficial for lots of small files avoiding lots of separate data
connections (particularly with SSL connection overhead).

So perhaps it is a good idea to add to ICS, not easy and I certainly
won't have time for several months, too busy adding Jose stuff like JWK,
JWS, JWT, ACME and OAuth2, mostly for Let's Encrypt SSL certificates,
then OpenSSL 1.1.1 and TLS/1.3, never mind my own projects.


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