NAME

       aesni — driver for the AES and SHA accelerator on x86 CPUs

SYNOPSIS

       To compile this driver into the kernel, place the following lines in your kernel configuration file:

             device crypto
             device cryptodev
             device aesni

       Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

             aesni_load="YES"

DESCRIPTION

       Starting  with  Intel Westmere and AMD Bulldozer, some x86 processors implement a new set of instructions
       called AESNI.  The set of six instructions accelerates the  calculation  of  the  key  schedule  for  key
       lengths  of  128, 192, and 256 of the Advanced Encryption Standard (AES) symmetric cipher, and provides a
       hardware implementation of the regular and the last encryption and decryption rounds.

       The processor capability is reported as AESNI in the Features2 line at boot.

       Starting with the Intel Goldmont and AMD Ryzen microarchitectures, some x86 processors  implement  a  new
       set  of  SHA  instructions.  The set of seven instructions accelerates the calculation of SHA1 and SHA256
       hashes.

       The processor capability is reported as SHA in the Structured Extended Features line at boot.

       The aesni driver does not attach on systems that lack both CPU capabilities.   On  systems  that  support
       only one of AESNI or SHA extensions, the driver will attach and support that one function.

       The aesni driver registers itself to accelerate AES and SHA operations for crypto(4).  Besides speed, the
       advantage  of  using  the  aesni driver is that the AESNI operation is data-independent, thus eliminating
       some attack vectors  based  on  measuring  cache  use  and  timings  typically  present  in  table-driven
       implementations.

SEE ALSO

       crypt(3), crypto(4), intro(4), ipsec(4), padlock(4), random(4), crypto(9)

HISTORY

       The aesni driver first appeared in FreeBSD 9.0.  SHA support was added in FreeBSD 12.0.

AUTHORS

       The aesni driver was written by Konstantin Belousov <kib@FreeBSD.org> and Conrad Meyer <cem@FreeBSD.org>.
       The key schedule calculation code was adopted from the sample provided by Intel and used in the analogous
       OpenBSD driver.  The hash step intrinsics implementations were supplied by Intel.

Debian                                         September 26, 2017                                       AESNI(4)