Re: [PATCH 12/38] crypto: drbg - Remove support for CTR_DRBG

[Stephan Mueller]

Am Montag, 20. April 2026, 08:33:56 Mitteleuropäische Sommerzeit schrieb Eric 
Biggers:

Hi Eric,

> Remove the support for CTR_DRBG.  It's likely unused code, seeing as
> HMAC_DRBG is always enabled and prioritized over it unless
> NETLINK_CRYPTO is used to change the algorithm priorities.

Just as an FYI: the CTR DRBG implementation is used, because it provides 
massive superior performance. The CTR DRBG implementation is lined up to use 
the AES-CTR mode directly. If you have an accelerated implementation like AES-
NI or ARM-CE, your performance increase is significant.

For example, on my M4 development system, the generation of 1GB of data from 
the CTR DRBG takes 90ms whereas the HMAC DRBG takes more than 4 seconds.

The default of HMAC DRBG, however, was used since it has a simple logic and 
smaller code.

Ciao
Stephan