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Network Working Group                                      Jim LiebRFC # 697                                                  SUMEX-AIMNIC # 32963                                                July 14, 1975CWD Command of FTPIntroductionThe Tenex file system support a "files only" directory.  This type ofdirectory cannot be "logged in" but it can be "connected to".  A logingives directory "owner" access to the job generated by the system and anaddress space in which the user can execute programs.   A connect allowsan existing job and its associated user "owner" access to a directorybut creates no address space.  The words "owner", "group", and"universal" or "public" determine which field of the protectionspecification is to be used to check the legality of a file accessrequest.ProblemThe Tenex FTP server does not allow an FTP Login to a "files only"directory.  The current protocol contains the CWD (Change WorkingDirectory) command which gets part of the "connect" functions but itdoes not grant "owner" access to the user.  Therefore, there is no way auser can access a "files only" directory as the "owner" (i.e. he cansupply the password).  This is undesirable for private directories ofthis type since it is uneconomical to define a user - directory "group"for so few directories and unrestricted "public" access may beundesirable.SolutionThere are two approach we can take.  Either we remove the distinction"files only" from the FTP login, or we create a command that does the"connect" function.  The restriction placed on "files only" directoriesis based on how we define a user of FTP to the server.  If we say thatany net user who knows the password to a directory has ownership of thatdirectory as far as FTP is concerned, then we have a solution.  If wewant an FTP login to be as restrictive as a user login, then we need thesecond alternative.Lieb                                                            [Page 1]

RFC 697                    CWD Command of FTP                  July 1975ProposalChange the protocol in one of the following ways:1.  Remove the restriction on "files only" directories for FTP logins or2.  Add an optional argument to the CWD (Change Working Directory)    command to specify the password string for the directory.  If the    password check is successful the user is granted ownership rights to    that directory.  If the password is not present or the check fails,    the command functions as it presently does and access is controlled    by the current protection mechanism.  Anonymous users should not be    allowed to use this mechanism to change their access to the file    system.       [ 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.            10/99 ]Lieb                                                            [Page 2]