BIND 10 #816: TSIG: update XFROUT to use TSIG

[BIND 10 Development]

#816: TSIG: update XFROUT to use TSIG
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                   Reporter:         |                 Owner:  zzchen_pku
  stephen                            |                Status:  reviewing
                       Type:         |             Milestone:
  enhancement                        |  Sprint-20110614
                   Priority:  minor  |            Resolution:
                  Component:         |             Sensitive:  0
  xfrout                             |           Sub-Project:  DNS
                   Keywords:         |  Estimated Difficulty:  5.0
            Defect Severity:  N/A    |           Total Hours:  0
Feature Depending on Ticket:  tsig   |
        Add Hours to Ticket:  0      |
                  Internal?:  0      |
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Changes (by stephen):

 * owner:  stephen => zzchen_pku


Comment:

 '''src/bin/xfrout/xfrout.py.in'''
 dns_xfrout_start()
 the check on rcode_ returned from _parse_query_message will not cope with
 errors other than FORMERR or NOTAUTH.  The logic should be:
 {{{
 if rcode_ == Rcode.NOTAUTH():
     return self._reply_query_with_error_rcode(msg, sock_fd, rcode_)
 elif rcode_ != Rcode.NOERROR():
     return self._reply_query_with_format_error(msg, sock_fd)
 }}}

 _reply_xfrout_query()
 Within _send_message_with_last_soa(), the length of the TSIG RR is added
 to the message_upper_len argument when checking against
 XFROUT_MAX_MESSAGE_SIZE.  However, if the main loop ends when the next
 packet to be sent should include a signature, on exit from the loop,
 message_upper_len will include the length of the TSIG RR.  In this case,
 the TSIG RR length is being included in the calculation twice.

 set_tsig_key_ring()
 Is the comment for this method correct?  It appears to apply to setting
 the TSIG key for a zone, not populating the key ring.


 '''src/bin/xfrout/tests/xfrout_test.py.in'''
 create_request_data_with_tsig()
 There appears to be some line of code (starting
 'self.create_mock_tsig_ctx...') temporarily commented out.

 The "magic number" 655020 seems to be related to the variable
 XFROUT_MAX_MESSAGE_SIZE in the main code.  As it is the relationship
 between the two - rather than the absolute value - that appears to be
 important, I suggest it be defined as a variable equal to
 (XFROUT_MAX_MESSAGE_SIZE - 15) (together with a comment explaining why
 there is the relationship).

-- 
Ticket URL: <http://bind10.isc.org/ticket/816#comment:7>
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