There are 2 types of FTP in use today on most mainframes. SFTP - which uses Open/SSH (SSHAGNT as client and SSHD as a server) and the encryption/authentication is generally provided by the use of RSA/DSA public/private key pairs. The public keys are exchanged and stored in known_hosts files (if acting as client) or authorized_keys file (if acting as server) - Uses Server PORT 22 and ephemeral ports
FTPS - completely different mechanism the AT/TLS functions are provided by ICSF and policy agent (PAGENT) - You must configure an FTPS TLS rule to allow the connection and the partner side also will require a similar rule. The encryption/authentication come from the PAGENT rule and the use of x.509 certificates. These are exchanged between partners and loaded onto the RACF keyring. The PAGNET rule points back to the keyring. - Uses Server PORT 990 by an old implicit default most sites use a different port and connect clients with ephemeral port ranges. FTPS handles MVS datasets better if possible use FTPS for MF to MF and use SFTP for MF to Other platforms(MS,UNIX,etc) MS -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Tom Brennan Sent: Tuesday, June 30, 2020 12:58 PM To: [email protected] Subject: [EXTERNAL] Re: AT-TLS ? Very Basic Questions I've tried to skim some of the AT-TLS doc, and even attended an IBM webinar last week, but I'm still missing what I imagine are important background points. Maybe someone here can explain things, but don't worry too much about it. Client and server programs like SSH/SSHD call programs such as OpenSSL to handle the encryption handshake and processing. So when you set those up, there is no AT-TLS needed for encryption. Same with the TN3270 server and client, as long as you set that up with keys and parameters on the host side, and settings on the client side. I'm thinking because of the name "Application Transparent" that AT-TLS was made for programs that DON'T have their own logic to call OpenSSL (or whatever) to do their own encryption. Let's use clear-text FTP as an example. So somehow, AT-TLS hooks into the processing and provides an encrypted "tunnel", kind of like VPN does, but only for that one application. Does that sound correct? If so, then the encryption is "transparent" to the FTP server code and FTP does not need to be changed, which I think is the whole idea here. Yet we now have an encrypted session. Does that sound correct? Then if so, what happens on the FTP client side? I certainly can't use the Windows FTP command, for example, because it's not setup for any kind of encryption. That's kind of my big question here. On 6/30/2020 1:44 AM, Lionel B Dyck wrote: > Sweet - thank you > > > Lionel B. Dyck <sdg>< > Website: https://www.lbdsoftware.com > > "Worry more about your character than your reputation. Character is > what you are, reputation merely what others think you are." - John > Wooden > > -----Original Message----- > From: IBM Mainframe Discussion List <[email protected]> On > Behalf Of kekronbekron > Sent: Tuesday, June 30, 2020 2:34 AM > To: [email protected] > Subject: Re: AT-TLS ? > > Hi LBD!, > > Check these out- > > > http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/PRS5416 > http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/PRS5415 > http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/PRS5414 > > - KB > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐ > On Monday, June 29, 2020 3:56 AM, Lionel B Dyck <[email protected]> wrote: > >> Anyone have any pointers for configuring AT-TLS on z/OS? >> >> Lionel B. Dyck <sdg>< >> Website: https://www.lbdsoftware.com https://www.lbdsoftware.com >> >> "Worry more about your character than your reputation. Character is >> what you are, reputation merely what others think you are." - John >> Wooden >> >> >> --------------------------------------------------------------------- >> - >> --------------------------------------------------------------------- >> - >> ----- >> >> For IBM-MAIN subscribe / signoff / archive access instructions, send >> email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. 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