Add NTLM SIGN flag for SMB Server - #1826
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Adds the NTLMSSP_NEGOTIATE_SIGN flag to the NTLM CHALLENGE message returned by the SMB server. This is needeed for clients that generate a SPNEGO mechListMIC which require signing to be enabled on the NTLM context.
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Jul 13, 2025
Adds the NTLMSSP_NEGOTIATE_SIGN flag to the NTLM CHALLENGE message returned by the SMB server. This is needeed for clients that generate a SPNEGO mechListMIC which require signing to be enabled on the NTLM context.
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Adds the NTLMSSP_NEGOTIATE_SIGN flag to the NTLM CHALLENGE message returned by the SMB server. This is needeed for clients that generate a SPNEGO mechListMIC which require signing to be enabled on the NTLM context.
Some background information, a client that sends an NTLM token wrapped in a SPNEGO payload can set the mechListMIC but the MS-NLMP docs are unclear what the signature behaviour is without the
NTLMSSP_NEGOTIATE_SIGNorNTLMSSP_NEGOTIATE_ALWAYS_SIGNflags. I've interpreted it as signing isn't supported and thus themechListMICfield cannot be computed. What should happen is if the client itself specified theNTLMSSP_NEGOTIATE_SIGNflag then the challenge should also respond with it which this change does. This is backed up by the protocol docs for CHALLENGE_MESSAGE