Re: Where has CRYPTO_TFM_MODE_nnn gone?

[Marc St-Jean <Marc_St-Jean@pmc-sierra.com>]

Herbert Xu wrote:
> On Fri, Jun 08, 2007 at 12:13:17PM -0700, Marc St-Jean wrote:
>  >
>  > In CBC mode we had a line of code copying cipher_desc.info to get the
>  > initialization vector. Such as:
>  >               /* Copy in IV */
>  >               memcpy((u8*)(sa->crypt_iv), desc->info,
>  >                       crypto_tfm_alg_ivsize(tfm));
>  >
>  > Now the only reference to the function I can find is in an IPsec comment
>  > from include/net/esp.h. Any tips on getting the size?
> 
> We now have two types of ciphers, simple ciphers and block ciphers.  The
> former only ever ecnrypts one block at a time, and therefore needs no IV.
> Only block ciphers have IVs.
> 
> The other change is that instead of having everything as crypto_tfm they
> all have their own types now.  So ciphers are crypto_cipher while block
> ciphers are crypto_blkcipher.
> 
> In your case your tfm should be of type crypto_blkcipher.  Then you simply
> call crypto_blkcipher_ivsize(tfm) to get the size.
>  
>  > Thanks, I have been looking at that code but unfortunately it supports
>  > fewer cryptos/hashes so does not answer all my questions.
> 
> The same concept still applies regardless of the actual number of modes.
> 
> Oh and yes you do register it multiple times, once for each combination
> of the blocking mode and the cipher.

Thanks for the info Herbert.

Marc