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.conf(5):
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
aesni
driver does not attach on systems
that lack the required CPU capability.
The
aesni
driver registers itself to
accelerate AES 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.
AUTHORS¶
The
aesni
driver was written by
Konstantin Belousov
⟨kib@FreeBSD.org⟩. The key schedule calculation code was adopted
from the sample provided by Intel and used in the analogous
OpenBSD driver.