2.4.4 FTP

The Kerberos V5 FTP program works exactly like the standard UNIX FTP program, with the following Kerberos features added:

-k realm

requests tickets for the remote host in the specified realm, instead of determining the realm itself.

-f

requests that your tickets be forwarded to the remote host. The -f argument must be the last argument on the command line.

protect level

(issued at the ftp> prompt) sets the protection level. “Clear” is no protection; “safe” ensures data integrity by verifying the checksum, and “private” encrypts the data. Encryption also ensures data integrity.

For example, suppose jennifer wants to get her RMAIL file from the directory ~jennifer/Mail, on the host daffodil.mit.edu. She wants to encrypt the file transfer. The exchange would look like the following:

     shell% ftp daffodil.mit.edu
     Connected to daffodil.mit.edu.
     220 daffodil.mit.edu FTP server (Version 5.60) ready.
     334 Using authentication type GSSAPI; ADAT must follow
     GSSAPI accepted as authentication type
     GSSAPI authentication succeeded
     200 Data channel protection level set to private.
     Name (daffodil.mit.edu:jennifer):
     232 GSSAPI user jennifer@ATHENA.MIT.EDU is authorized as jennifer
     230 User jennifer logged in.
     Remote system type is UNIX.
     Using binary mode to transfer files.
     ftp> protect private
     200 Protection level set to Private.
     ftp> cd ~jennifer/MAIL
     250 CWD command successful.
     ftp> get RMAIL
     227 Entering Passive Mode (128,0,0,5,16,49)
     150 Opening BINARY mode data connection for RMAIL (361662 bytes).
     226 Transfer complete.
     361662 bytes received in 2.5 seconds (1.4e+02 Kbytes/s)
     ftp> quit
     shell%

The full set of options to Kerberos V5 FTP are discussed in the Reference section of this manual. (see FTP Reference)