> Von: linux-crypto-owner@vger.kernel.org [linux-crypto-owner@vger.kernel.org]" im Auftrag von "Corentin LABBE [clabbe.montjoie@gmail.com]
> Gesendet: Montag, 30. März 2015 19:59
> An: linux-crypto@vger.kernel.org
> Cc: linux-sunxi@googlegroups.com
> Betreff: problem with testing a CTR block cipher mode which is partially working
> 
> hello
> 
> I am trying to add the CTR (counter) block cipher mode for AES on my Security System driver.
> 
> When testing with the tcrypt module I got the following result:
> [ 1256.986989] alg: skcipher: Test 1 failed on encryption for ctr-aes-sunxi-ss
> [ 1256.987004] 00000000: 87 4d 61 91 b6 20 e3 26 1b ef 68 64 99 0d b6 ce
> [ 1256.987013] 00000010: 40 94 25 91 d7 b4 4f 49 ab c1 9d 33 a4 4e f6 54
> [ 1256.987023] 00000020: ce 58 d2 f0 01 8f 92 a2 5f 2c bb 66 13 8b 9d 76
> [ 1256.987032] 00000030: 30 fa 4a 40 b1 67 2e f3 46 b7 9a 7c ba 91 0b a2
> 
> As you can see the first ciphered block is correct (according to testmgr.h), the subsequent blocks are bad.
> 
> So Could I assume that the setting of key and IV are good (at least for the first cipher pass.
> 
> The number of inputs(register) are limited and I have tested near all the possibility.
> Any idea of what could be wrong.
> 

had a similar challenge a few months ago. I had to take care about

- counter IV is big endian (implemented it little endian in first place)
- CTR allows to encrypt data that does not need to be amultiple of 16 bytes.

Markus

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