Andrew Bartlett schrieb:
> On Fri, 2008-09-05 at 22:25 +0200, Stefan (metze) Metzmacher wrote:
>> Hongwei Sun schrieb:
>>> Metze/Andrew,
>>>
>>>   The subkey in the EncAPRepPart of the AP-REP should be used as the 
>>> session key when the mutual authentication is enabled(as described in RFC 
>>> 4121).    When DES and RC4 are used in Kerberos, the implementation is 
>>> based on RFC1964 (instead of RFC4121).  According to RFC1964, you can pick 
>>> the subkey in AP_REQ as the session key as it is the same as the subkey in 
>>> AP_REP, but this is not true when AES is used because both subkeys are 
>>> different (again AES means RFC4121 being used, not RFC1964).       This 
>>> explains what you observed.   We will add the information to [MS-KILE] to 
>>> describe how the session key is selected.
>>>
>>>    The session key returned from  Kerberos package can be used for SMB 
>>> signing as described in the section 4.3 of  [MS-SMB].  You have to truncate 
>>> the keys to 128 bits in your code  because SMB does the truncation on the 
>>> windows side.
>>>
>>>    I ran the similar testing as you did.  I had one Vista machine connected 
>>> to Windows 2008 DC/KDC and configured AES256-CTS-HMAC-SHA1-96 as Kerberos 
>>> encryption type with mutual authentication enabled.  I cannot duplicate 
>>> your SMB signing problem(see the network capture attached). It is working 
>>> between Windows servers and clients.
>> I got it working, the session key isn't truncated for the SMB signing.
>>
>> The problem was that we reseted the sequence number when updating the
>> session key from the initiator subkey to the acceptor subkey between the
>> session setup request and response.
>>
>> Also windows signs the response with the acceptor subkey, so that the
>> client needs to check the signature after processing the response.
> 
> I think I hit the same issue Samba/Samba last night (after I enabled
> mandatory smb signing in our server).  Is your fix for this up
> somewhere?

http://gitweb.samba.org/?p=metze/samba/wip.git;a=shortlog;h=v4-0-aes
http://gitweb.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=b53e6387e30010509034835acf88b91b380ff44a

metze

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