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Member "tin-2.4.1/doc/auth.txt" (28 Aug 2013, 4373 Bytes) of package /linux/misc/tin-2.4.1.tar.gz:


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    1                   Authentication to a NNTP server with tin
    2 
    3 Tin is able to do authentication to news servers according to the "Common
    4 NNTP Extensions" (this document is available at [1]). There are several ways
    5 of authentication described in that text which are referred to as Original
    6 AUTHINFO, AUTHINFO GENERIC, and AUTHINFO SIMPLE. Tin supports the Original
    7 AUTHINFO and the AUTHINFO GENERIC methods and if tin is linked against
    8 libgsasl and the server announces it as described in RFC 3977 [2] it
    9 supports the AUTHINFO SASL PLAIN mechanisem as described in RFC 4643 [3]. In
   10 addition to answers to authentication requests as described in the "Common
   11 NNTP Extensions", tin also provides authentication at connection startup.
   12 
   13 Unfortunately, you cannot rely on the response codes of authentication
   14 requests as described in the "Common NNTP Extensions"; today's news servers
   15 mostly send NNTP codes 480, regardless of the type of authentication they
   16 expect. Therefore, authentication is always done in the same manner: First,
   17 tin tries an AUTHINFO GENERIC authorization. If this fails, Original
   18 AUTHINFO is used. If this does not work for you (which it should), please
   19 contact me to track this problem down. There are known problems with the
   20 reference nntp server available at ftp.academ.com -- this is a server bug
   21 and not tin's fault; if you need a patch or workaround, drop me a mail.
   22 
   23 Authentication requests will be handled whenever they occur; the command
   24 that caused the request will be sent again.
   25 
   26 For an authentication with the Original AUTHINFO method, tin needs a
   27 user-name and a password for the current news server. This information is
   28 obtained from a file .newsauth in the $HOME directory. The format of the
   29 .newsauth file is as follows:
   30 
   31 news.server1 password1 [username1]
   32 news.server2 password2 [username2]
   33 ...
   34 
   35 The first line matching the current news server is taken. The delimiters
   36 between the fields MUST be spaces or TABS. If a password contains spaces,
   37 you have to surround the whole password by double quotes. If no user-name is
   38 given for the current news server, the user-id of the user who started tin
   39 is assumed. Mind that tin expects unix line endings ('\n'), a
   40 .newsauth-file with dos line endings ('\r\n') or mac line endings ('\r')
   41 is likely to cause trouble.
   42 
   43 Security consideration: Make sure that the .newsauth file cannot be read by
   44 others. Tin checks the permissions of the file and complains if they are
   45 insecure (i.e., if they are not -rw-------) but continues.
   46 
   47 If you do not have a .newsauth file in your $HOME directory, tin prompts
   48 you for a user-name and a password. This is not done automatically at
   49 connection startup, because there is no way for tin to find out if an
   50 authentication at this time is needed. If you need to authenticate at the
   51 beginning of your news session, use the -A option when invoking tin or just
   52 provide a .newsauth file.
   53 
   54 The AUTHINFO GENERIC authentication was implemented by someone else and has
   55 not been tested by me since I do not know a server that supports this.
   56 
   57 To use AUTHINFO GENERIC, set up an environment variable NNTPAUTH with the
   58 command and its parameters to invoke for authentication. The content of
   59 NNTPAUTH is also used as the authenticator in the AUTHINFO GENERIC response
   60 to the server. The environment variable NNTP_AUTH_FDS is used to store file
   61 descriptors for reading from and writing to the server, and for a temporary
   62 file ("cookie"); the three descriptors are separated by dots. The
   63 authentication command can take use of NNTP_AUTH_FDS when invoked; it should
   64 exit successful if the authentication was accepted.
   65 
   66 If NNTPAUTH is empty or not available, tin sends an "authinfo generic any
   67 <user-id>" command to the server and expects the result as a NNTP response
   68 code.
   69 
   70 The AUTHINFO SASL PLAIN authentication method requires tin to be linked
   71 against libgsasl.
   72 
   73 The AUTHINFO SIMPLE authentication method is not supported by tin (and
   74 possibly won't be since nobody seems to use it and there are some problems
   75 with the protocol). If you need this, drop me a message or see the source
   76 code in auth.c. With the specification at [1], the implementation should not
   77 be difficult.
   78 
   79 Dirk Nimmich (2000-01-22)
   80 <nimmich@uni-muenster.de>
   81 
   82 References:
   83 [1] <http://www.karlsruhe.org/rfc/rfc2980.txt>
   84 [2] <http://www.karlsruhe.org/rfc/rfc3977.txt>
   85 [3] <http://www.karlsruhe.org/rfc/rfc4643.txt>