Re: Passwords with Lan Manager (LM) under Windows

From: Thor (Hammer of God) (thor_at_hammerofgod.com)
Date: 09/22/05

  • Next message: Sahir Hidayatullah: "Re: Whitespace in passwords"
    To: "Craig Wright" <cwright@bdosyd.com.au>, <pand0ra.usa@gmail.com>, <pen-test@securityfocus.com>
    Date: Thu, 22 Sep 2005 00:54:20 -0700
    
    

    I saw this one first, so I go top-down (It's getting late for me, so I'll
    get right to it.)

    First off-- don't just Google for it and reference a single article with
    out-of-context "cut and paste" elements from:
    http://www.microsoft.com/technet/itsolutions/cits/mo/smf/smfsecad.mspx

    You quote:
    "advisable to make IPsec-based authentication a part of the authentication
    process"

    The actual text reads:
    "As mentioned earlier, L2TP relies on other protocols for its security. L2TP
    authentication is best for the exchange of packets between the LAC and the
    LNS. Therefore, it is advisable to make IPSec-based authentication a part of
    L2TP." Other quotes are similar..

    My original post was to content regarding actual authentication protocol
    mechanisms like LM, NTLM, NTLMv2 and Kerberos. The article you reference
    does indeed use the phrase "IPSec Authentication," but as any who reads it
    will see, the term is used to describe the higher level protocol deployment;
    a higher
    level protocol that has, as I said before, 3 authentication mechanisms
    available to establish a connection. Here's the article that should be
    referenced:
    http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/ServerHelp/be7540ff-2a1d-47b4-8e7f-501ec692ad11.mspx

    The relevant text being:
    <meat>
    Overview of authentication methods:
    For authentication, IPSec allows you to use the Kerberos V5 protocol,
    certificate-based authentication, or preshared key authentication.
    </meat>

    Which is what I said the first time.

    And not to be blunt, but your previous post describing the IPSec channel
    setup of "system" and "client" is just wrong... the above link has many
    other references that will help you understand how IPSec Policies and
    component filters and actions work. The "2 parts" are the default
    negotiation, and the subsequent filter definitions. Both of which still
    require a PSK, Kerberos auth, or cert to be established.

    The data is all right there if you want to check it out-- I don't see any
    reason to argue about it, and it's all right there in the documentation...
    If you want to discuss this off-list, (in a constructive way) I'm happy to
    do so, but I think we're done on the list... (except for my last response to
    the first message- then I'm hitting the sack ;)

    t

    ----- Original Message -----
    From: "Craig Wright" <cwright@bdosyd.com.au>
    To: "Thor (Hammer of God)" <thor@hammerofgod.com>; <pand0ra.usa@gmail.com>;
    <pen-test@securityfocus.com>
    Sent: Thursday, September 22, 2005 12:01 AM
    Subject: RE: Passwords with Lan Manager (LM) under Windows

    PPPS

    To drop a quote from Technet (Microsoft Corporation)
    "IPsec based Authentication and integrity" and
    "Initial security proposals involve using IPsec-based authentication"
    "advisable to make IPsec-based authentication a part of the
    authentication process"
    "IPsec-based authentication is recommended"

    To quote the "rmt-pi" working party from the IETF
    "provided using IPsec-based authentication at the network layer"

    "I'd have to say that there is no such thing..." - Please inform MSFT -
    they seem to think there is

    Craig

    -----Original Message-----
    From: Thor (Hammer of God) [mailto:thor@hammerofgod.com]
    Sent: 22 September 2005 3:46
    To: Craig Wright; pand0ra.usa@gmail.com; pen-test@securityfocus.com
    Subject: Re: Passwords with Lan Manager (LM) under Windows

    Well, that's an issue with the client, not NTLMv2. NTLMv2 is tight. LM
    sucks- that's obvious (and it was IBM, not MS that gave us that one.)
    And yes, you can use precomputed tables against NTLM hashes, but not
    against NTLMv2... The NTLM hash is keyed off of the password, but NTLMv2
    hashes up the password with the user's domain/user data when generating
    the key...
    You can't precompile that data into a rainbow, you know?

    Regarding the "IPsec based auth" reference (here I go again), I'd have
    to say that there is no such thing... IPSec negotiation in Windows can
    be based on one of three mechanisms: A pre-shared key, Kerberos, or a
    cert-- it is not an authentication protocol in itself... (the cert being
    the strongest IMO).

    t

    ----- Original Message -----
    From: "Craig Wright" <cwright@bdosyd.com.au>
    To: "Thor (Hammer of God)" <thor@hammerofgod.com>;
    <pand0ra.usa@gmail.com>; <pen-test@securityfocus.com>
    Sent: Wednesday, September 21, 2005 10:05 PM
    Subject: RE: Passwords with Lan Manager (LM) under Windows

    Further to the last post
    There are a number of issues with NTLMv2 and legacy applications such as
    Windows RAS that cause lower levels of authentication

    I still say that Kerberos or IPsec based auth is the best policy in
    windows. LanMan, NTLMv1 or V2 are vulnerable.

    Precomputed tables may have been uncommon 12 months ago - but that was
    then and this is now.

    Cain & Abel will use sorted Rainbow Tables for Cryptanalysis attacks

    Craig

    -----Original Message-----
    From: Thor (Hammer of God) [mailto:thor@hammerofgod.com]
    Sent: 22 September 2005 12:00
    To: Craig Wright; pand0ra.usa@gmail.com; pen-test@securityfocus.com
    Subject: Re: Passwords with Lan Manager (LM) under Windows

    ----- Original Message -----
    From: "Craig Wright" <cwright@bdosyd.com.au>
    To: <pand0ra.usa@gmail.com>; <pen-test@securityfocus.com>
    Sent: Wednesday, September 21, 2005 12:32 PM
    Subject: RE: Passwords with Lan Manager (LM) under Windows

    > Even NTLMv2 will break the hashing into chunks which are able to be
    > individually broken down.

    I'm not sure what you mean... NTLMv2 uses a single 128bit key for the
    hash, challenge and response... Or are you referring to the NTLM2
    session response key (56+56+16)? If so, that is not the same thing as
    NTLMv2...
    Can
    you elaborate please ?

    t

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  • Next message: Sahir Hidayatullah: "Re: Whitespace in passwords"

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