Re: Question about ctr mode 3des-ede IV len

[Jussi Kivilinna]

Hello,

07.12.2016, 14:43, Longpeng (Mike) kirjoitti:
> Hi Jussi and Herbert,
> 
> I saw serveral des3-ede testcases(in crypto/testmgr.h) has 16-bytes IV, and the
> libgcrypt/nettle/RFC1851 said the IV-len is 8-bytes.
> 
> Would you please tell me why these testcases has 16-bytes IV ?

Because I used same tool to create test-vectors which I had previously used to create AES/Camellia/Serpent/Twofish test-vectors. So, I must have forgotten to change 16-byte IV generation to 8 bytes and thus those testcases in crypto/testmgr.h have wrong length. The extra trailing 8 bytes are not used and can be removed.

-Jussi

> 
> Thank you. :)
>