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(#358) Catch NTLM hash if non-SSP authentication #367

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merged 26 commits into from
Nov 26, 2021
Merged

(#358) Catch NTLM hash if non-SSP authentication #367

merged 26 commits into from
Nov 26, 2021

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lubiedo
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@lubiedo lubiedo commented Oct 26, 2021

This PR will enable PyRDP to catch the NTLM Hash during a client's connection even when it was not executed with CredSSP authentication enabled and the server enforces it. To achieve this it will cut connection with the server and create a challenge PDU for the client to respond with an authentication message.

cc @obilodeau

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lubiedo commented Nov 2, 2021

Getting closer to finishing this PR. @obilodeau: let me know what you think and if you have some changes for me to add to this.

@lubiedo lubiedo changed the title Catch NTLM hash if non-SSP authentication (#358) Catch NTLM hash if non-SSP authentication Nov 11, 2021
@lubiedo lubiedo linked an issue Nov 11, 2021 that may be closed by this pull request
Grab the Net-NTLM hash before closing an NLA connection #358
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obilodeau reviewed Nov 16, 2021
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Things are taking shape. Here's my review. A lot of little things, nothing major. Great work!

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Another round of review/comments.

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Another important problem showed up. There seems to be a problem if we don't already have a copy of the server's certificate:

[2021-11-23 16:50:03,586] - INFO - Ellyn175837 - pyrdp.mitm.connections.x224 - Server requires CredSSP. Closing connection with server and attempting to capture NTLM hashes.
Unhandled Error
Traceback (most recent call last):
  File "/usr/lib/python3.9/asyncio/base_events.py", line 596, in run_forever
    self._run_once()
  File "/usr/lib/python3.9/asyncio/base_events.py", line 1890, in _run_once
    handle._run()
  File "/usr/lib/python3.9/asyncio/events.py", line 80, in _run
    self._context.run(self._callback, *self._args)
  File "/home/olivier/Documents/gosecure/src/pyrdp/venv/lib/python3.9/site-packages/twisted/internet/asyncioreactor.py", line 273, in _onTimer
    self.runUntilCurrent()
--- <exception caught here> ---
  File "/home/olivier/Documents/gosecure/src/pyrdp/venv/lib/python3.9/site-packages/twisted/internet/base.py", line 994, in runUntilCurrent
    call.func(*call.args, **call.kw)
  File "/home/olivier/Documents/gosecure/src/pyrdp/pyrdp/mitm/RDPMITM.py", line 229, in doClientTls
    privKey, certFile = self.certs.lookup(cert)
builtins.UnboundLocalError: local variable 'cert' referenced before assignment

obilodeau
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Another important problem showed up. There seems to be a problem if we don't already have a copy of the server's certificate:

I might have a fix for this in the works.

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lubiedo commented Nov 24, 2021

Thanks for the reviews @obilodeau! Will work on them ASAP.

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lubiedo commented Nov 24, 2021

Fix for major issue #367 (comment) fixed with commit 527a03b

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Very minor suggestions/comments

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@lubiedo lubiedo added the enhancement New feature or request label Nov 26, 2021
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This PR sparks joy! 🌟

@obilodeau obilodeau merged commit 25b3ee0 into GoSecure:master Nov 26, 2021
This was referenced Nov 26, 2021
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@obilodeau obilodeau mentioned this pull request Jan 5, 2022
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obilodeau added a commit to alxbl/pyrdp that referenced this pull request Jan 6, 2022
@lubiedo @obilodeau
Capture the NetNTLM hash if server enforces NLA (GoSecure#367)
24f3477 
If we don't use the NLA redirection feature and the server doesn't support downgrade attacks then the best we can do is steal the hash. Some ASN.1 BER improvements were required as well.

Fixes GoSecure#358

Co-authored-by: Olivier Bilodeau <obilodeau@gosecure.net>
obilodeau added a commit that referenced this pull request Jan 17, 2022
@lubiedo @obilodeau
Capture the NetNTLM hash if server enforces NLA (#367)
d8408a8 
If we don't use the NLA redirection feature and the server doesn't support downgrade attacks then the best we can do is steal the hash. Some ASN.1 BER improvements were required as well.

Fixes #358

Co-authored-by: Olivier Bilodeau <obilodeau@gosecure.net>
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Grab the Net-NTLM hash before closing an NLA connection
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