aesni (4)

Leading comments

Copyright (c) 2010 Konstantin Belousov <kib@FreeBSD.org>
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   d...

(The comments found at the beginning of the groff file "man4/aesni.4freebsd".)

NAME

aesni - driver for the AES accelerator on Intel CPUs

SYNOPSIS

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

device crypto device aesni

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf5:

aesni_load="YES"

DESCRIPTION

Starting with some models of Core i5/i7, Intel 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. The ifconfig driver does not attach on systems that lack the required CPU capability.

The ifconfig driver registers itself to accelerate AES operations for crypto(4). Besides speed, the advantage of using the ifconfig 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 ifconfig driver first appeared in Fx 9.0 .

AUTHORS

An -nosplit The ifconfig driver was written by An Konstantin Belousov Aq kib@FreeBSD.org . The key schedule calculation code was adopted from the sample provided by Intel and used in the analogous Ox driver.