Re: [PATCH] tcrypt: add self test for des3_ebe cipher operating in cbc mode

[Adrian-Ken Rueegsegger <rueegsegger@swiss-it.ch>]

Neil Horman wrote:
> On Sun, Jun 01, 2008 at 03:44:23AM +0200, Adrian-Ken Rueegsegger wrote:
>> Neil Horman wrote:
>>> On Sat, May 31, 2008 at 08:46:22AM +1000, Herbert Xu wrote:
>>>> On Fri, May 30, 2008 at 07:26:38PM +0200, Adrian-Ken Rüegsegger wrote:
>>>>> I was wondering why you created your own test vectors. Wouldn't standardized test vectors by NIST or ANSI be preferable?
>>>> If you could post a patch with those that would be very much
>>>> appreciated.  Thanks!
>> I am putting together a patch using the test vectors found at [3] and the ones I gathered from ANSI X9.52 and ISO/IEC FDIS 10116:2005. Strange enough the ANSI and ISO test vectors pass while the ones from NIST do not yield the expected results. I have not yet identified the specific differences between the various test vector sets. It is not clearly stated if/which padding was employed so that might be the reason...
>>
> 
> I thought that TDES input/output vectors had to be an even multiple of the key
> length.  As such if the vectors aren't an even multiple, doesn't padding have to
> be employed?

It's actually multiple of the cipher's block length, which all plain-/ciphertext values of the test vectors are. I some cases keys are also padded if one only supplies 2 keys and not 3 (192 bits in total). Since I used the test vectors with three distinct 64 bit keys I was wrong with my thinking that padding could be an issue. As you mentioned in the other mail, I will see if something with my setup is off.

Adrian
>>> For future reference, do you have a link where NIST standard test vectors can be
>>> obtained?
>> A good place to start is [1]. More specifically for TDES: [2] and [3]. Note that the tests described in [2] will not work with the current DES3 implementation since the employed keys will be identified as weak keys and the setkey operation would fail.
>>
>> By the way: when explicitly trying to set a weak key for DES3 I got the following warning:
>>
>> setkey() failed flags=0
>>
>> Shouldn't the flags be set to CRYPTO_TFM_RES_BAD_KEY_SCHED at that point (see crypto/des_generic.c, line 873)?
> I ran into this too when I wrote my vector. I'm not sure why this is happening,
> as it appears the *flags->crt_flags | FLAGS statements should set these.  I'm
> looking into why
> Neil
> 
>> Thanks,
>> Adrian
>> __________
>>
>> [1] - http://csrc.nist.gov/groups/STM/cavp/standards.html
>> [2] - http://csrc.nist.gov/publications/nistpubs/800-20/800-20.pdf
>> [3] - http://csrc.nist.gov/groups/STM/cavp/documents/des/tripledes-vectors.zip
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