[jcifs] Creating DCE/RPC Requests

[christofer.dutz at c-ware.de]

Hi Mike,

I compared the Wireshark dumps and actually found a difference.
In the PsExec call to bind to the svcctl pipe two Ctx Items are sent and in the JCIFS version only one is sent.
PsExec:
- Item 1:
    - Interface: 367abb81-9844-35f1-ad32-98f038001003 
    - Interface Ver: 2 
    - Interface Ver minor: 0
    - Transfer Syntax: 8a885d04-1ceb-11c9-9fe8-08002b104860 Version 2
- Item 2:
    - Interface: 367abb81-9844-35f1-ad32-98f038001003 
    - Interface Ver: 2 
    - Interface Ver minor: 0
    - Transfer Syntax: 6cb71c2c-9812-4540-0300-000000000000 Version 1

In the JCIFS version only item one is sent, but that one is identical. So I guess that the remote host is expecting to receive this two-item binding request.
Unfortunately I can't figure out how to make JCIFS send such a binding request.

Help is greatly appreciated here.

Chris



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-----Ursprüngliche Nachricht-----
Von: Michael B Allen [mailto:ioplex at gmail.com] 
Gesendet: Donnerstag, 5. Januar 2012 09:17
An: christofer.dutz at c-ware.de
Cc: jcifs at lists.samba.org
Betreff: Re: [jcifs] Creating DCE/RPC Requests

On Wed, Jan 4, 2012 at 2:04 AM, christofer.dutz at c-ware.de <christofer.dutz at c-ware.de> wrote:
> Hi,
>
>
>
> I am currently digging into using the DCE/RPC parts of JCIFS. 
> Unfortunately I am running into problems.
>
> Iused midlc (Version 0.6.1) To generate a JCIFS compatible stub for 
> the svcctl Service and am now trying to call it. Unfortunately I am 
> getting
> "jcifs.dcerpc.DcerpcException: DCERPC_FAULT_PROTO_ERROR"
>
>
>
> Here comes my code:
>
>
>
>             rpc.policy_handle scHandle = new rpc.policy_handle();
>
>             SvcCtl.OpenSCManager openSCManagerRpc = new 
> SvcCtl.OpenSCManager(host, null, 0x0001 | 0x0002, scHandle);
>
>
>
>             // Connection-oriented DCE/RPC over SMB named pipes.
>
>             DcerpcHandle handle = DcerpcHandle.getHandle("ncacn_np:" + 
> host
> + "[\\PIPE\\svcctl]",
>
>
> ConcurrentNtlmAuthenticator.getInstance().getNtlmPasswordAuthenticatio
> n());
>
>             try {
>
>                 handle.sendrecv(openSCManagerRpc);           ßThe 
> Exception is thrown when executing this line.
>
>                 if (openSCManagerRpc.retval != 0) {
>
>                     throw new SmbException(openSCManagerRpc.retval, 
> true);
>
>                 }
>
>             } catch(Exception e) {
>
>                 e.printStackTrace();
>
>             } finally {
>
>                 try {
>
>                     handle.close();
>
>                 } catch(IOException ioe) {
>
>                     ioe.printStackTrace();
>
>                 }
>
>             }
>
>
>
> So what am I doing wrong? I would be really glad if you could help me 
> get started, as Googling doesn't seem to get me very far (There seems 
> to be almost no information on this available)

Hi Chris,

The IDL is probably wrong. Look at Samba IDL. There is a lot of IDL available in Microsoft documentation now too. Note that midlc only understands a small critical subset of MIDL. In practice you really need to get two captures and compare them side-by-side to verify that the NDR segments are encoded in an identical way. This is true even if you get it to actually work.

Mike

--
Michael B Allen
Java Active Directory Integration
http://www.ioplex.com/