fix(mssql): handle TDS error when NTLM challenge absent and fix local-auth flow

[azoxlpf]

Description

Fixes #1065: when the server answers the integrated LOGIN7 with a TDS error instead of NTLM, we no longer call parse_challenge() on that data (no more crash). We log a short message and still finish host setup so SQL auth with --local-auth works. Tested against MSSQL on Debian where integrated Windows auth is not available. Parsing is minimal not a full TDS error decode just enough to avoid the exception.

Type of change

Insert an "x" inside the brackets for relevant items (do not delete options)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Deprecation of feature or functionality
• This change requires a documentation update
• This requires a third party update (such as Impacket, Dploot, lsassy, etc)
• This PR was created with the assistance of AI (list what type of assistance, tool(s)/model(s) in the description)

Setup guide for the review

install mssql server on debian with docker :

docker run -e "ACCEPT_EULA=Y"  -e "MSSQL_SA_PASSWORD=Password123!"  -p 1433:1433 --name mssql -d mcr.microsoft.com/mssql/server:2022-latest

Screenshots (if appropriate):

Before :

After :

Checklist:

Insert an "x" inside the brackets for completed and relevant items (do not delete options)

• I have ran Ruff against my changes (poetry: poetry run ruff check ., use --fix to automatically fix what it can)
• I have added or updated the tests/e2e_commands.txt file if necessary (new modules or features are required to be added to the e2e tests)
• If reliant on changes of third party dependencies, such as Impacket, dploot, lsassy, etc, I have linked the relevant PRs in those projects
• I have linked relevant sources that describes the added technique (blog posts, documentation, etc)
• I have performed a self-review of my own code (not an AI review)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (PR here: https://github.com/Pennyw0rth/NetExec-Wiki)

[NeffIsBack]

Thanks for the bug fix PR!

[NeffIsBack]

Shouldn't we properly parse the message tho? Do you know what exactly the structure is? Then we could probably just parse it with impacket.

[azoxlpf]

Shouldn't we properly parse the message tho? Do you know what exactly the structure is? Then we could probably just parse it with impacket.

The integrated-auth failure path now pulls MsgText with Impacket’s TDS_INFO_ERROR (scan for 0xAA / 0xAB in the LOGIN7 response, full packet then the legacy [3:] slice). Dropped the manual UTF-16 heuristic. LGTM :

[NeffIsBack]

Few small formatting changes left :)

[NeffIsBack]

Fyi, added a NTLM:False banner as this is more accurate imo. LGTM: