Movatterモバイル変換

Network Working Group                                       Bob BresslerRequest for Comments #487                                   BBNNIC #15065                                                  6 April 1973Free File Transfer    In the past several months, many people have commented to me abouttheir difficulty in transferring files.  The hang up appears to be withsystems that have some flavor of security, but on which the user has noaccess privileges.  Specifically, the FTP server demands a user andpassword before it will grant any system access.  The loophole whichpeople have been using is the MAIL FILE facility, which is both limitedin scope and intended for other purposes.    A frequently used model for file protection is to define threelevels of user access:  1) only the user himself; 2) all users in agroup; 3) everyone.  Up until now, "everyone" has meant anyone alreadygranted logon privileges.  A new class is, perhaps, needed to covereveryone, exclusive of whether or not they are logged on.    With all this in mind, I propose the following course of action:    If a user connects to an FTP server and makes a file request withoutsupplying a user name-password, the server should then examine the fileaccess parameters.  If the file is listed as accessible to anyone, thenthe transfer should be allowed to proceed.    This scheme can be implemented so as not to yield file creationsprivileges - for example, store commands can be implemented via anappend mechanism.  If I wanted a file sent to me I could create an emptyfile with unlimited append access.  I would then inform the foreign userto store (append?) to that file.    The problem of accounting is somewhat more complex.  Clearly,storing a file in a user's directory can be charged to that user.  Whenretrieving a file from a general system directory, there is no "user"specified, and overhead may have to be billed.  The former case involvedboth CPU time for transfer and secondary storage charges for storing thenew file.  In the latter case, only CPU charges are involved, and thesemay be sufficiently small to not cause a major problem.    BBN TENEX has agreed to modify their FTP server to allow generalaccess transfers as described above.  Specific details for usage will beavailable when installation is complete.  I urge other systems to makethis service available, if only on an experimental basis.  The successof such an experiment will be judged by the reaction of the general userBressler                                                        [Page 1]

RFC 487                    Free File Transfer                 April 1973community and the uses to which FTP is put.NOTE:  Bob Clements tells me that the BBN TENEX implementation will       probably require a user name of something like "FREE" or       "ANONYMOUS", but not require a password.RB/jm       [ This RFC was put into machine readable form for entry ]       [ into the online RFC archives by Alex McKenzie with    ]       [ support from GTE, formerly BBN Corp.             9/99 ]Bressler                                                        [Page 2]