AESNI(4)               FreeBSD Kernel Interfaces Manual               AESNI(4)

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(7), 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.

FreeBSD 13.1-RELEASE-p6          July 29, 2020         FreeBSD 13.1-RELEASE-p6