[cifs-protocol] [MS-NRPC] Problem encrypting data when use AES based Netlogon SChannel

[Stefan (metze) Metzmacher]

Hi,

>    According to MS-NRPC pg 111, bit 17 (indicated as  bit R) of  negotiable flag is actually referring to  "supports the NetrServerPasswordSet2 functionality".  
> In the packet trace that attached earlier, I had successfully negotiated the session key (from pkt 519-523) with the DC using unprotected RPC and established the SChannel.    
> However, when sending the encrypted message (encrypted with AES-key derived from the session key) over Schannel to DC, DC   responded with DCE RPC fault with error = 0x00000721. 
> 
> And,  I also tried to use the initialization vector constructed using the last block (size=8 bytes) of the encrypted Confounder field, same error code returned from DC. 
> 
> There's no problem if only integrity is negotiated.   
> So, I suppose the ivec mentioned in the MS-NRPC spec  to encrypt the message might not correct  ?   

Take a look at this branch, it contains working code, at least it worked
a year ago against w2k8r2.
http://gitweb.samba.org/?p=metze/samba/wip.git;a=shortlog;h=refs/heads/master3-schannel

Maybe that helps.
metze

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