[FFmpeg-devel] libavutil: added camellia block cipher

supraja reddy supraja0493 at gmail.com
Fri Dec 26 16:18:27 CET 2014


Hello,

I made a small change in the decrypt function which I should have done so
earlier.
Please let me know of the further changes/fixes.

Thanks,

Supraja

On Thu, Dec 25, 2014 at 4:11 AM, supraja reddy <supraja0493 at gmail.com>
wrote:

> Hello,
>
> Thank you for your reviews. I have attached the updated patch .
>
> You are using a single array K for all the keys, without distinguishing
>> between
>> kw, k and ke as in the rfc. This makes code harder to read/maintain with
>> no
>> real gain I guess. Any reason why you made this decision?
>>
>
> I have created a single array for all keys to make the key scheduling more
> compact as you have seen. Please let me know if there is any other way to
> do so .
>
>>
>> > +    Zl ^= ((Zr << 8) | (Zr >> 24));
>> > +    Zr ^= ((Zl << 16) | (Zl >> 16));
>> > +    Zl ^= ((Zr >> 8) | (Zr << 24));
>> > +    Zr ^= ((Zl >> 8) | (Zl << 24));
>>
>> This optimization is correct, just curious, where did you read about it?
>>
>
> I have found a specifications page for camellia by the authors of the
> algorithm. Here's the link to it :
> www.cryptrec.go.jp/cryptrec_03_spec_cypherlist_files/PDF/06_01espec.pdf
> I hope I am allowed to do so. Please let me know if you find anything
> useful in the above link that I can incorporate.
>
> Please let me know if there are any further changes.
>
> Thanks,
>
> Supraja
>
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