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Indy TIdFTP TSL1.2 Error 534 Protection level C not allowed

I have an older Delphi project where in we use the TIdFTP client. I have been unable to get it to work there so I have started a side project where I can test the component. I am also running a FileZilla FTP server with the minimum TLS version set to 1.2. However when I try to run the List procedure in Delphi I get a response saying

534 Protection level C not allowed

FTP Server log showing the described issue:

26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Command       AUTH TLS
26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Response      234 Using authentication type TLS.
26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Command       USER test
26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Response      331 Please, specify the password.
26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Command       PASS ***
26-08-2024 08:32:54   FTP Session 5 127.0.0.1    Response      230 Login successful.
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       FEAT
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      211-Features:
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      211 End
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       OPTS UTF8 ON
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      202 UTF8 mode is always enabled. No need to send this command
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       TYPE I
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      200 Type set to I
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       SYST
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      215 UNIX emulated by FileZilla.
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       TYPE I
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      200 Type set to I
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       PBSZ 0
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      200 PBSZ=0
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Command       PROT C
26-08-2024 08:32:54   FTP Session 5 127.0.0.1... Response      534 Protection level C not allowed
26-08-2024 08:32:59   FTP Server                 Status        Session 5 ended gracefully.

I have tried changing the settings but no luck.

Delphi Code:
Delphi Code

IdFTP Settings: IdFTP Settings

IdSSLIOHandlerSocketOpenSSL settings: IdSSLIOHandlerSocketOpenSSL settings

I have not used Delphi for very long and this is my first time posting here, so let me know if there is anything else you need.

Solution

  • Your server (rightfully) does not allow unencrypted file transfers.

    So you need to change the DataPortProtection property from ftpdpsClear (PROT C) to ftpdpsPrivate (PROT P).