Re: Get current IV value in decrypt AES256 CTR mode

On Fri, Jan 8, 2021 at 10:44 AM Xamix <[email protected]> wrote:
>
> I'm using the library with the templated AES CTR decryptor:
>
> CryptoPP::CTR_Mode<CryptoPP::AES>::Decryption decryptor_ctr_;
>
> I decrypt input data which is previouslly encoded data blocks by using the following function:
>
> decryptor_ecb_.ProcessData(output, input, input_len);
>
> Now I want to get get the IV value after encoding, in order to save it.
> I haven't found any function to retrieve the current IV value which is normally incremented by 1 after each block encoding.
> I can compute it myself but the decryptor should have the value currently after encoding.
>
> Is there a solution to get back the current IV value after encoding?

No, there is no function to retrieve the IV.

There is a function to retrieve the next IV, which only generates a
random block with size of IVsize().

Jeff

-- 
You received this message because you are subscribed to "Crypto++ Users". More information about Crypto++ and this group is available at http://www.cryptopp.com and http://groups.google.com/forum/#!forum/cryptopp-users.
--- 
You received this message because you are subscribed to the Google Groups "Crypto++ Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
To view this discussion on the web visit https://groups.google.com/d/msgid/cryptopp-users/CAH8yC8mSJ-kPWjtD%3Dv%3Da-agBVU1jcUOMn%2BbNezeYJ6h7rw662g%40mail.gmail.com.