BIND 10 #2595: cmdctl with chusr crashes due to permission issue

[BIND 10 Development]

#2595: cmdctl with chusr crashes due to permission issue
-------------------------------------+-------------------------------------
            Reporter:  jinmei        |                        Owner:
                Type:  defect        |  jinmei
            Priority:  medium        |                       Status:
           Component:  cmd-ctl       |  reviewing
            Keywords:                |                    Milestone:
           Sensitive:  0             |  Sprint-20130205
         Sub-Project:  Core          |                   Resolution:
Estimated Difficulty:  3             |                 CVSS Scoring:
         Total Hours:  0             |              Defect Severity:  N/A
                                     |  Feature Depending on Ticket:
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Comment (by jinmei):

 First, I noticed one (unrelated) style issue and fixed it in the branch.

 Replying to [comment:11 jelte]:

 > > - shouldn't we close the socket here?
 > > {{{#!python
 > >         except (CmdctlException, IOError) as cce:
 > >             logger.error(CMDCTL_SSL_SETUP_FAILURE_READING_CERT, cce)
 > >             # raise socket error to finish the request
 > >             raise socket.error
 > > }}}
 > >   like the case of `SSLError`?  In fact, probably due to this bindctl
 > >   now seems to revert to the previous unhelpful error message.
 >
 > doh, of course

 Actually, it was still not sufficient.  On a closer look, I realized
 catching ECONNRESET at bindctl shouldn't help, because in this case
 it's not "connection reset" (getting TCP RST).  At the TCP level it
 would be a close of the connection (FIN), and even that's not really
 correct.  As the (unhelpful) error message shows, the error was caught
 at the SSL level and returned to bindcmd.  So what we need to catch is
 an sslSSLError exception whose errno is `SSL_ERROR_EOF`, e.g:

 {{{#!python
         try:
             response = self.send_POST('/login', param)
             data = response.read().decode()
             return (response, data)
         except ssl.SSLError as err:
             self._print("SSL error while sending login information: ",
 err)
             if err.errno == ssl.SSL_ERROR_EOF:
                 self._print("Please check the logs of b10-cmdctl, there
 may "
                             "be a problem accepting SSL connections, such
 "
                             "as a permission problem on the server "
                             "certificate file.")
             raise FailToLogin()
         except socket.error as err:
             self._print("Socket error while sending login information: ",
 err)
             raise FailToLogin()
 }}}
 (note that we'll need some additional tests).  I'd also note that in
 Python 3.3 this will have to be ssl.SSLEOFError (not sure if the errno
 check also works).

 Other changes look okay.

-- 
Ticket URL: <https://bind10.isc.org/ticket/2595#comment:12>
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