This is an extract from the CVS src code, server.c
It seems to indicate a method of communicating with CVS and loggin in via
telnet.
Yet I cannot duplicate this manually, can anyone help?
/* The Authentication Protocol. Client sends:
*
* BEGIN AUTH REQUEST\n
* <REPOSITORY>\n
* <USERNAME>\n
* <PASSWORD>\n
* END AUTH REQUEST\n
*
* Server uses above information to authenticate, then sends
*
* I LOVE YOU\n
*
* if it grants access, else
*
* I HATE YOU\n
*
* if it denies access (and it exits if denying).
*
* When the client is "cvs login", the user does not desire actual
* repository access, but would like to confirm the password with
* the server. In this case, the start and stop strings are
*
* BEGIN VERIFICATION REQUEST\n
*
* and
*
* END VERIFICATION REQUEST\n
*
* On a verification request, the server's responses are the same
* (with the obvious semantics), but it exits immediately after
* sending the response in both cases.
*
* Why is the repository sent? Well, note that the actual
* client/server protocol can't start up until authentication is
* successful. But in order to perform authentication, the server
* needs to look up the password in the special CVS passwd file,
* before trying /etc/passwd. So the client transmits the
* repository as part of the "authentication protocol". The
* repository will be redundantly retransmitted later, but that's no
* big deal.
*/
#ifdef SO_KEEPALIVE
/* Set SO_KEEPALIVE on the socket, so that we don't hang forever
if the client dies while we are waiting for input. */
{
int on = 1;
(void) setsockopt (STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE,
(char *) &on, sizeof on);
}
#endif
/* Make sure the protocol starts off on the right foot... */
if (getline_safe (&tmp, &tmp_allocated, stdin, PATH_MAX) < 0)
/* FIXME: what? We could try writing error/eof, but chances
are the network connection is dead bidirectionally. log it
somewhere? */
;
if (strcmp (tmp, "BEGIN VERIFICATION REQUEST\n") == 0)
verify_and_exit = 1;
else if (strcmp (tmp, "BEGIN AUTH REQUEST\n") == 0)
;
else if (strcmp (tmp, "BEGIN GSSAPI REQUEST\n") == 0)
{
#ifdef HAVE_GSSAPI
free (tmp);
gserver_authenticate_connection ();
return;
#else
error (1, 0, "GSSAPI authentication not supported by this server");
#endif
}
else
error (1, 0, "bad auth protocol start: %s", tmp);
#ifndef AUTH_SERVER_SUPPORT
error (1, 0, "Password authentication not supported by this server");
