[cifs-protocol] [MS-SAMR] AEAD-AES-256-CBC-HMAC-SHA512

[Andreas Schneider]

Hello Dochelp,

I'm trying to implement support for AEAD-AES-256-CBC-HMAC-SHA512 from [MS-
SAMR] 3.2.2.4 AES Cipher Usage.

This is not really easy as there are some details unclear. I would love to 
write a unit test for AEAD-AES-256-CBC-HMAC-SHA512.

Could you please provide hexdump of the buffers used in encryption from a 
SamrSetInformationUser2 level 31 from a test platform.

When it performs the following:

Let enc_key ::= HMAC-SHA-512(CEK, SAM_AES256_ENC_KEY_STRING)
Let mac_key ::= HMAC-SHA-512(CEK, SAM_AES256_MAC_KEY_STRING)
Let Cipher ::= AES-CBC(enc_key, IV, secret_plaintext)
Let AuthData ::= HMAC-SHA-512(mac_key, versionbyte + IV + Cipher + 
versionbyte_length)


I would like to have hexdumps of the following buffers:

* cek (16byte sesssion key)
* enc_key
* mac_key
* IV
* secret_plaintext
* cipher
* authdata

The RFC implementation provides something like that, see:
https://tools.ietf.org/id/draft-mcgrew-aead-aes-cbc-hmac-sha2-03.html#rfc.section.5.4

This would allow me to write a unit test and figure out the details what in my 
implementation something goes wrong. I can then provide feedback to improve 
the documentation.


Thank you very much!


Best regards


	Andreas Schneider


-- 
Andreas Schneider                      asn at samba.org
Samba Team                             www.samba.org
GPG-ID:     8DFF53E18F2ABC8D8F3C92237EE0FC4DCC014E3D