I realize this is off topic, but looking over this perhaps someone can
suggest a solution to my sftp problems on Win after seeing this.

I am attempting to connect to a private site using sftp. Sort of.
Using a client they supplied, along with many switch clicks and such,
we were able to connect securely. Actually you connect "in the clear"
using normal FTP on port 21, but then after connecting to the sever,
the client issues this command:

[11:24:16] AUTH TLS
[11:24:16] 234 AUTH TLS-C/TLS OK.
[11:24:16] Connected. Exchanging encryption keys...
[11:24:17] Session Cipher: 128 bit RC4
[11:24:17] SSL encrypted session established.
[11:24:17] PBSZ 0
[11:24:17] 200 PBSZ 0 OK.

The client then sends the USER/PASS and a few setup commands (like
PASV) before I see this...

[11:24:17] PROT P
[11:24:17] 200 PROT P OK, data channel will be secured.
[11:24:17] CCC
[11:24:17] 200 CCC Context Enabled.

Can someone more familiar with modern FTP explain to me what all of
this means? I assume that the first block of logged text is switching
from FTP to SFTP, in a manner of speaking, in order to protect the
login. Once that is done it then sends additional commands to make the
server use the same encryption on the data channel too. But what is
CCC? Something to do with the command channel? Isn't this already
protected due to the AUTH?

Is there some way I can use flags to do this with curl? I see that
there are a number of flags that turn certain encryption options on at
various stages of curl's operation, but I really don't understand this
stuff enough to match up those options with the various commands I'm
seeing here in the log.

Maury
Received on 2007-11-28