[Twisted-Python] ldaptor problem with STARTTLS and python 3

[Thomas Westfeld]

>-----Original Message-----
>From: Twisted-Python [mailto:twisted-python-bounces at twistedmatrix.com] On
>Behalf Of Adi Roiban
>Sent: Tuesday, May 28, 2019 12:39 PM
>To: Twisted general discussion
>Subject: Re: [Twisted-Python] ldaptor problem with STARTTLS and python 3
>
>On Tue, 28 May 2019 at 11:22, Thomas Westfeld
><thomas.westfeld at currenta.de> wrote:
>>
>> Dear all,
>>
>> I am experiencing an error when trying to use the quick usage example posted on
>the ldaptor github page https://github.com/twisted/ldaptor . I have included the
>starttls command to promote the connection to an encrypted one, but I am
>experiencing an deprecation warning:
>>
>> DeprecationWarning: LDAPStartTLSInvalidResponseName.__str__ method is
>deprecated and will not be used for getting bytes representation in the future
>releases, use LDAPStartTLSInvalidResponseName.toWire instead
>>   category=DeprecationWarning)
>>
>> This puzzles me as I cannot track this error down. The usual strategy to introduce
>debugging print statements or start the debugger like "import pdb; pdb.set_trace()"
>does not work. I would appreciate help here how to debug this deferred code.
>>
>> Besides this warning I am receiving no output whatsoever. Also print statements in
>the example method do not print anything, which is strange to me.
>>
>> To debug it on a networking level, I have wiresharked the ldap communication and
>it seems fine (see below):
>>
>> REQUEST
>>
>> Transmission Control Protocol, Src Port: 53964, Dst Port: 389, Seq: 1, Ack: 1,
>Len: 31
>> Lightweight Directory Access Protocol
>>     LDAPMessage extendedReq(1)
>>         messageID: 1
>>         protocolOp: extendedReq (23)
>>             extendedReq
>>                 requestName: 1.3.6.1.4.1.1466.20037 (LDAP_START_TLS_OID)
>>         [Response In: 2587]
>>
>> RESPONSE
>>
>> Transmission Control Protocol, Src Port: 389, Dst Port: 53964, Seq: 1, Ack: 32,
>Len: 46
>> Lightweight Directory Access Protocol
>>     LDAPMessage extendedResp(1)
>>         messageID: 1
>>         protocolOp: extendedResp (24)
>>             extendedResp
>>                 resultCode: success (0)
>>                 matchedDN:
>>                 errorMessage:
>>                 responseName: 1.3.6.1.4.1.1466.20037 (LDAP_START_TLS_OID)
>>         [Response To: 2581]
>>         [Time: 0.245555000 seconds]
>>
>> I have posted the example code with the starttls command in this gist:
>>
>> https://gist.github.com/westfeld/bb1d5e8727ce13910623933e041e9782
>
>It looks like a bug.
>
>With the Python3 migration the usage of the implicit __str__ for
>serialization/marshaling of the LDAP messages was removed.
>
>Please add a new issue/ticket/bug in Github for ldaptor.
>
>I am debugging these things by patching the ldap code and adding a PDB call here
>https://github.com/twisted/ldaptor/blob/d3c191921bd32c359a3e4974c2251f9af852a
>b2b/ldaptor/_encoder.py#L56
>
>then you can go up and see where str is called, and consider if it
>should be repalced with .toWire()
>
>Cheers
>
>--
>Adi Roiban

Dear all,

it turns out to be an issue with binary vs. string. The __str__ method was called by the errback only. This has been fixed in pull request #147 already. All the observed errors have been fixed in the pre-release 19.1 version of ldaptor. The example is working with STARTTLS when using HEAD.

Thanks for the great community for fixing things so quickly.

I am looking forward to the 19.1. release.


Regards,
Thomas